2015年第46卷第4期共收录55篇 1.Accession number: 20151900832358 Title: Enhancement mechanism investigation of centrifugal pump based on bionic coupling functional surface Authors: Tian, Limei1 ; Mei, Haoran1; Li, Xinhong2; Wang, Yinci1; Yang, Le2; Shao, Peng2 Author affiliation: 1 Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun, China 2 Jilin City AO JI TONG PUMP Co., Ltd., Jilin, China Corresponding author: Tian, Limei Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 65-69 and 119 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Dolphin's special skin structure has characteristics of drag reduction, by mimicking this structure, a kind of bionic coupling functional surface which has practical engineering application value was designed. It was applied on the surface of a centrifugal pump impeller to investigate the efficiency enhancement of the pump through contrast experimental method. The experimental results showed that the pump efficiency was improved by 3% by using this kind of bionic coupling functional surface. The hardness of surface material had influence on the pump efficiency. The mechanism of efficiency enhancement of bionic coupling functional surface was the coupling deformation between elastic surface material and bionic structure on the basal material, which can decrease the drag of impeller surface, absorb some energy and effectively reduce the turbulent kinetic energy of the inlet and outlet of impeller, thus, the hydraulic loss would be decreased. Number of references: 15 Main heading: Energy efficiency Controlled terms: Bionics - Centrifugal pumps - Drag - Impellers - Kinetic energy - Kinetics - Pumps Uncontrolled terms: Centrifugal pump impellers - Efficiency enhancement - Enhancement mechanism - Experimental methods - Functional surfaces - Practical engineering applications - Surface materials - Turbulent kinetic energy Classification code: 525.2 Energy Conservation - 601.2 Machine Components - 618.2 Pumps - 731.1 Control Systems - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics DOI: 10.6041/j.issn.1000-1298.2015.04.011 Database: Compendex 2.Accession number: 20151900832350 Title: Analysis on distribution of electric field strength of small-scale cone-jet electro-spraying Authors: Shi, Yanling1 ; Luo, Zhibin2, 3; Gan, Yunhua2, 3 ; Xu, Min2, 3 Author affiliation: 1 College of Engineering, South China Agricultural University, Guangzhou, China 2 School of Electric Power, South China University of Technology, Guangzhou, China 3 Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization, Guangzhou, China Corresponding author: Gan, Yunhua Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 15-20 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Experiments on electro-spraying were carried out under a combined electric field based on micro-scale combustion system by using ethanol as fuel. A stable cone-jet mode was obtained. And theoretical calculation was performed based on the cone-jet mode. The distribution of electric field strength was calculated by using ellipse integral method and the relationship between Cartesian coordinates and polar coordinates. The results showed that the electric field strength produced by the ring electrode alone at the center of nozzle reached its maximum value, which was 0 V/m at the position of the center of ring electrode. It increased with the increase of cone angle when all the other conditions were kept the same. The electric field strength produced by the ring electrode could be ignored compared with that produced by the nozzle electrode due to the much bigger diameter of ring electrode and smaller electrode spacing. The distribution of electric field strength in the jet region was axis-symmetry and extremely non-uniform in the angle range φ of 0°~49.3°. The strength in the center of nozzle was very small while it was bigger around the outer side of nozzle, which enhanced the electric induction. Changing the voltage of the ring electrode put little effect on the electric field distribution in the jet region, but the electric field strength in the spraying region was greatly increased. Number of references: 18 Main heading: Electric fields Controlled terms: Combustion - Electrodes - Nozzles Uncontrolled terms: Cartesian coordinate - Combustion systems - Distribution of electric fields - Electric field distributions - Electric field strength - Electric induction - Ring electrodes - Theoretical calculations Classification code: 521.1 Fuel Combustion - 631.1 Fluid Flow, General - 701.1 Electricity: Basic Concepts and Phenomena - 704.1 Electric Components DOI: 10.6041/j.issn.1000-1298.2015.04.003 Database: Compendex 3.Accession number: 20151900832376 Title: Temperature dynamics in bale silage with damaged cover Authors: Cheng, Hong1, 2 ; Sun, Yurui1 ; Buescher, Wolfgang3; Cheng, Qiang1 Author affiliation: 1 Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, China Agricultural University, Beijing, China 2 College of Information Science and Technology, Agricultural University of Hebei, Baoding, China 3 Institute of Agricultural Engineering, University of Bonn, Bonn, Germany Corresponding author: Sun, Yurui Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 194-199 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The deterioration risk of bale silage is relatively high because of a high surface-area to volume ratio. Therefore, the damages of plastic covers of bales should receive particular attention since it may often occur during removing or transportation process. When bales are punctured, oxygen is allowed to permeate the silage and subsequently aerobic organisms flourish and metabolize the products of fermentation, and the temperature inside the bales will rise up again. So temperature is a key indicator when the material is noticed to be “heating” since while oxygen comes into contact with the silage. In order to forecast the risks of aerobic deterioration of silage, grass bale silage and alfalfa bale silage were selected as study objects. The method which used to embed temperature sensors into the bale to measure the temperature was proposed. The self-developed multi-sensor experimental system with a specific penetration shaft and cone (V-structure) was used. While the cone penetrated into bale, the thermal-couple sensor followed the cone into the bale. If the cone arrived at the place desired, the cone would extract but the thermal sensors would stay at the place. It can put the sensors into bale without introducing air followed. Two schemes measuring temperature changes in punctured bale were designed. The temperature of planned locations in bale was monitored. It was detected that the temperature of the silage which was closer from the damaged cover rose sooner. Paired t test was done between the corresponding values from the upper and the lower within bale silage. The test results showed that two temperature rising processes of upper and lower had a significant difference. By temperature curve comparison of the same silage materials with different dry matter contents, it was found that the temperature rising of silage with higher dry matter was faster. Furthermore, to measure the temperature field inside bale, a specific penetrometer was designed. It was fixed on the platform of measurement and controlled during temperature measurement. Based on the data of temperature distribution, the temperature distribution in bale silage could be visualized in 3D map. It is a powerful tool to analyze temperature distribution around the bale silage in multi-angle. Number of references: 14 Main heading: Temperature distribution Controlled terms: Deterioration - Fixed platforms - Oxygen - Temperature - Temperature measurement Uncontrolled terms: Bale silage - Cover damage - Dry matter content - Experimental system - Measuring temperature - Temperature curves - Temperature dynamics - Transportation process Classification code: 511.2 Oil Field Equipment - 641.1 Thermodynamics - 804 Chemical Products Generally - 944.6 Temperature Measurements - 951 Materials Science DOI: 10.6041/j.issn.1000-1298.2015.04.029 Database: Compendex 4.Accession number: 20151900832352 Title: Internal flow characteristic of screw centrifugal pump based on PIV Authors: Quan, Hui1, 2 ; Li, Rennian1, 2 ; Su, Qingmiao3; Han, Wei1, 2; Jiang, Lei1, 2; Jin, Yi1, 2 Author affiliation: 1 School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, China 2 Key Laboratory of Fluid Machinery and Systems, Lanzhou; Gansu Province, China 3 Lanzhou Huayu Space Technology Applications Ltd., Lanzhou, China Corresponding author: Li, Rennian Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 28-32 and 58 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to research the internal flow mechanism of screw centrifugal pump, the PIV testing technology was used after the pump was improved with the transparent handling. The velocities of shaft section and radial section at different stages were obtained. The flow of each section was received and then the internal flow in screw centrifugal pump was revealed. The results showed that the perturbation of physical parameters at the whole shaft section was bigger than the one at radial section. The vortex was appeared obviously at shaft section of impeller passage and the vortex volume increased significantly in the impeller passage which was deep into volute. With the depth of the fluid flow, it caused fluid force reallocation by the spiral vane segment. At radial section, velocity was rotated along with the direction of the flow line. Simultaneously, there was a trend that fluid moved from the center to the outside due to the centrifugal force from the centrifugal section, which played an important role after the spiral section. The spiral propulsion of spiral section and the energy conversion of centrifugal section were cooperated with each other to make up the working process of screw centrifugal pump. Number of references: 12 Main heading: Flow of fluids Controlled terms: Centrifugal pumps - Centrifugation - Fluid dynamics - Impellers - Pumps - Screws - Testing - Velocity measurement - Vortex flow Uncontrolled terms: Centrifugal Forces - Different stages - Internal flow characteristics - Particle image velocimetries - Physical parameters - Screw centrifugal pumps - Section - Testing technology Classification code: 423.2 Non Mechanical Properties of Building Materials: Test Methods - 601.2 Machine Components - 605 Small Tools and Hardware - 618.2 Pumps - 631.1 Fluid Flow, General - 802.3 Chemical Operations - 943.3 Special Purpose Instruments DOI: 10.6041/j.issn.1000-1298.2015.04.005 Database: Compendex 5.Accession number: 20151900832380 Title: Glass transition and state diagram of mango Authors: Zhao, Jinhong1, 2 ; Zhu, Minghui1, 2; Wen, Xin1, 2; Jiang, Yundong1, 2; Kang, Jiaqi1, 2; Ni, Yuanying1, 2 Author affiliation: 1 College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China 2 National Engineering Research Center for Fruit and Vegetable Processing, China Agricultural University, Beijing, China Corresponding author: Ni, Yuanying Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 226-232 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Sorption isotherms of freeze-dried mango (variety Tainong No. 1) were determined at 25 and the data were modeled by GAB model. A J-shaped sorption isotherm of mango was presented and the GAB monolayer moisture contents were observed to be 0.107 g/g. The unfreezable and freezable water contained in freeze-dried mango was examined to develop the state diagram. The state diagram of mango was developed using glass transition line(glass transition temperature vs solids content), freezing curve(initial freezing point vs solids content) and maximal-freeze-concentration condition. Freezing points and glass transition temperature were measured by differential scanning calorimetry (DSC) as a function of water content. Freezing points were fitted according to the Clausius-Clapeyron model and the parameter E was determined as 0.071 by using non-linear optimization technique. Glass transition was fitted to Gordon-Taylor model. The constants Tgs and k were estimated as 15.7 and 4.42, respectively. Glass transition increased with the increase of solids content, which was due to the plasticizing effect of water in mango solids. Freezing points decreased as total solids content increased. The maximal-freeze-concentration condition was calculated to be at a solid content of 84% with characteristic temperature of end point of freezing (T'm) being -32.8 and characteristic glass transition temperature (T'g) being -52.9. These characteristics revealed that the quantities of unfreezable water were 0.16 g/g indicating the amount of reactive water. The state diagram of mango can be used in evaluating the storage stability as a function of temperature and moisture content. Moreover, it can also be used to design drying and freezing processes. Number of references: 26 Main heading: Glass transition Controlled terms: Adsorption isotherms - Calorimeters - Calorimetry - Differential scanning calorimetry - Digital storage - Freezing - Fruits - Glass - Isotherms - Moisture - Moisture determination - Nonlinear programming - Temperature Uncontrolled terms: Characteristic temperature - Clausius-Clapeyron model - Mango - Monolayer moisture content - Non-linear optimization - Plasticizing effects - State diagram - Total solids contents Classification code: 641.1 Thermodynamics - 722.1 Data Storage, Equipment and Techniques - 801 Chemistry - 801.4 Physical Chemistry - 812.3 Glass - 815.1 Polymeric Materials - 821.4 Agricultural Products - 822.2 Food Processing Operations - 922 Statistical Methods - 944.2 Moisture Measurements - 944.6 Temperature Measurements DOI: 10.6041/j.issn.1000-1298.2015.04.033 Database: Compendex 6.Accession number: 20151900832009 Title: Dynamic control method of infeed angle for continuous flat press Authors: Zhang, Guoliang1, 2 ; Qu, Guofu3; Hou, Xiaopeng1; Liu, Xinyu3; Zhu, Jun3; Zhou, Yucheng1 Author affiliation: 1 Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, China 2 College of Forestry, Agricultural University of Hebei, Baoding, China 3 China Foma(Group)Co., Ltd., Beijing, China Corresponding author: Zhou, Yucheng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 372-378 and 343 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Adjustability of infeed angle is of great importance to design and use of the whole continuous flat press which is used to produce wood-based panels. Based on the capability of bending deformation of the steel, a method using bending deformation of integral infeed upper hot platen shaped as rectangular in cross section to adjust infeed angle was put forward. On the basis of analyzing curving principle of bending deformation and deducing geometrical relationship between radius of curvature and height of curving, bending strength of infeed upper hot platen was calculated by simulation and a distributed system as well as human-computer interaction control system based on fieldbus was established. Displacement gradient progressive-approximation algorithm used for hydraulic cylinders was set up and the system was applied to continuous flat press designed in China. The results showed that bending deformation of upper hot platen met requirements of bending strength, the method of adjusting infeed angle and the control algorithm could be used to achieve progressivity of displacement changing for hydraulic cylinders and dynamic adjusting of infeed angle, and the control precision could be reached by field debugging. The maximum error was 0.4 mm between theoretical and practical value, and maximum horizontal difference was 0.6 mm when radius of curvature was 100 000 mm. Number of references: 14 Main heading: Bending (deformation) Controlled terms: Algorithms - Approximation algorithms - Bending strength - Computer control systems - Cylinders (shapes) - Deformation - Distributed computer systems - Human computer interaction - Mechanical actuators - Presses (machine tools) - Program debugging Uncontrolled terms: Curving height - Displacement gradients - Distributed systems - Dynamic controls - Geometrical relationship - Hydraulic cylinders - Infeed angles - Radius of curvature Classification code: 408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 603.1 Machine Tools, General - 722.2 Computer Peripheral Equipment - 722.4 Digital Computers and Systems - 723.1 Computer Programming - 723.5 Computer Applications - 732.1 Control Equipment - 921 Mathematics DOI: 10.6041/j.issn.1000-1298.2015.04.055 Database: Compendex 7.Accession number: 20151900832364 Title: Numerical simulation of soil moisture infiltration under negative pressure irrigation based on HYDRUS-2D Authors: Ji, Ronghua1 ; Wang, Tingting1; Qi, Lijun2 ; Yang, Zhilun2 Author affiliation: 1 College of Information and Electrical Engineering, China Agricultural University, Beijing, China 2 College of Engineering, China Agricultural University, Beijing, China Corresponding author: Qi, Lijun Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 113-119 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Based on the theory of unsaturated soil water dynamics and characteristics of soil moisture movement under negative pressure irrigation, a moisture infiltration model was proposed. The time-varying rules of moisture infiltration at the vertical soil profile on condition of negative pressure irrigation were simulated by moisture infiltration model of HYDRUS-2D. Result showed that the relative error between simulated and measured value was 2%~4%, which was within a reasonable range. The soil moisture infiltration rules under the negative pressure irrigation can be described effectively by the model. Moisture infiltration with different soils (soil and matrix in Beijing area) and different sizes of emitters (radius varied 8, 10 and 12 cm) were simulated. The simulation results indicated that emitter size was a significant influence factor for soil moisture infiltration. The initial moisture migration rate was faster with larger emitter than that with smaller emitter. Meanwhile, the delay at the beginning of infiltration was shorter with larger emitter. There was a positive correlation between infiltration rate and emitter size, and water infiltration rate increased with the increase of the radius of emitter. Number of references: 22 Main heading: Infiltration Controlled terms: Irrigation - Moisture - Soil moisture - Soils Uncontrolled terms: HYDRUS-2D - Infiltration modeling - Infiltration rate - Moisture movement - Negative pressures - Positive correlations - Unsaturated soil - Water infiltration Classification code: 483.1 Soils and Soil Mechanics - 801.4 Physical Chemistry - 821.3 Agricultural Methods DOI: 10.6041/j.issn.1000-1298.2015.04.017 Database: Compendex 8.Accession number: 20151900832006 Title: Continuity conditions for λ-Bézier curves of degree n Authors: Hu, Gang1, 2 ; Wei, Guo3; Ji, Xiaomin1 Author affiliation: 1 School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, China 2 School of Science, Xi'an University of Technology, Xi'an, China 3 University of North Carolina at Pembroke, Pembroke; NC, United States Corresponding author: Ji, Xiaomin Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 351-359 and 337 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: With the aim to tackle the problem that the engineering complex curves can not be constructed by using a single curve, the continuity condition of the λ-Bézier curves of degree n with shape control parameters were investigated. The λ-Bézier curves of degree n not only inherit the outstanding properties of the corresponding classical Bézier curve of degree n, but also have a good performance on adjusting their shapes by changing shape control parameters. In the particular case where the shape control parameter equals to zero, the λ-Bézier curves degenerate to the classical Bézier curve. Firstly, the Bernstein-like basis functions of arbitrary order n were constructed by using a recursive formula from the initial basis functions, and the geometric property at the endpoints of the λ-Bézier curves were obtained, such as interpolation at the corners, the derivative at end-points and the second derivative at end-points. Secondly, based on the analysis of basis functions and terminal properties, the necessary and sufficient conditions of G1, G2 continuity and C1, C2 continuity between two adjacent λ-Bézier curves were proposed. Finally, some properties of the continuity condition for the λ-Bézier curves and applications in λ-Bézier curves design were discussed. In addition, the influence rules of the shape parameters on the complex λ-Bézier curves shape were studied. The modeling examples showed that the proposed method was effective and easy to implement, which greatly enhanced the ability to construct complex curves by using λ-Bézier curves. Number of references: 27 Main heading: Functions Controlled terms: Point contacts Uncontrolled terms: Basis functions - Continuity conditions - Geometric continuity - Geometric properties - Recursive formula - Second derivatives - Shape parameters - Terminal properties Classification code: 714.2 Semiconductor Devices and Integrated Circuits - 921 Mathematics DOI: 10.6041/j.issn.1000-1298.2015.04.052 Database: Compendex 9.Accession number: 20151900832356 Title: Numerical simulation of clearance flow in francis turbine with weep holes Authors: Zhou, Daqing1 ; Chen, Yang1 Author affiliation: 1 College of Energy and Electrical, Hohai University, Nanjing, China Corresponding author: Zhou, Daqing Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 53-58 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The whole flow passage of Francis turbine including clearance structure such as cavity between crown and top cover, weep hole and seal passage of runner was built to study pressure distributions and velocity distributions in main passage as well as clearance flow characteristics by CFD method. Variation rules of leakage flux and static pressure in chamber head of the turbine was revealed due to different micro channel clearance widths, weep hole diameters and numbers. ICEM structured grid was used to divide the key components to analyze the seal clearance flow. The sizes of grid nodes were set up as one smaller regional area and another larger one according to the large space between the main passage and seal passage. The numerical results showed that seal widths, weep hole diameter and number had an impact on flux leakage and pressure in chamber head. According to numerical simulation results, the weep hole number was determined as 6, weep hole diameter was 40 mm and seal width was 1 mm. Under the rated condition, turbine installation efficiency was 86.75% with flow rate of 5 109 m3/h, and the clearance leakage reach 0.3% of the whole unit flow. The calculation results agreed well with the test, which showed that clearance flow calculation method could provide scientific basis for the design of Francis hydraulic turbine weep hole diameter and number, and details of seal gap structure. The results would benefit to avoiding the hydraulic vibration and ensure the secure and efficient operation of units. Number of references: 16 Main heading: Computational fluid dynamics Controlled terms: Computer simulation - Francis turbines - Hydraulic motors - Numerical models - Turbine components Uncontrolled terms: Calculation results - Clearance flow - Flow calculations - Flow charac-teristics - Hydraulic vibration - Turbine installation - Weep holes - Whole flow passage Classification code: 617 Turbines and Steam Turbines - 617.1 Hydraulic Turbines - 632.2 Hydraulic Equipment and Machinery - 723.5 Computer Applications - 921 Mathematics DOI: 10.6041/j.issn.1000-1298.2015.04.009 Database: Compendex 10.Accession number: 20151900832354 Title: Numerical analysis and prediction of hydraulic performance for axial-flow pumping system with adjustable outlet guide vanes Authors: Yang, Fan1, 2 ; Liu, Chao1, 2; Tang, Fangping1, 2; Xie, Rongsheng1; Chen, Feng1 Author affiliation: 1 School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou, China 2 Hydrodynamic Engineering Laboratory of Jiangsu Province, Yangzhou University, Yangzhou, China Corresponding author: Yang, Fan Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 40-46 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to investigate the effect of adjustable outlet guide vane on hydraulic performance of axial-flow pumping system, the pumping system with seven different adjustable angles of outlet guide vane were simulated based on the RNG k-Ε turbulent model and Reynolds time-averaged equations. Vectorgraph of airfoil flow were analyzed under different operating conditions at different adjustable angles of guide vane. BP-ANN prediction model about effect of adjustable outlet guide vane on the hydraulic performance of axial-flow pumping system was established based on numerical results. The effectiveness of prediction model was verified by using theoretical analysis and numerical simulation. The results showed that the high-efficiency area moved to the large flow rate direction with the adjustable angle of guide vane increased along clockwise, otherwise, it moved to the small flow rate direction. The internal flow field of guide vane was improved by adjusting angle and the flow separation of tail and guide vane inlet ledge were decreased or eliminated, which would improve hydraulic efficiency of pumping system. The input model of the BP-ANN prediction model is presented and the number of middle layer is fixed by many tests. The characteristic data of 42 pumping system operating conditions are used to train the network model, and the data of the other seven pumping system operating conditions are used to test the network model. The prediction accuracy of BP-ANN model was below 1%, which can meet the requirement of practical engineering. Number of references: 15 Main heading: Inlet flow Controlled terms: Axial flow - Flow rate - Flow separation - Forecasting - Neural networks - Numerical analysis - Pumping plants - Pumps Uncontrolled terms: Different operating conditions - Hydraulic efficiency - Hydraulic performance - Outlet guide vanes - Practical engineering - Prediction accuracy - Pumping systems - Time-averaged equations Classification code: 446 Waterworks - 617 Turbines and Steam Turbines - 618.2 Pumps - 631 Fluid Flow - 631.1 Fluid Flow, General - 723.4 Artificial Intelligence - 921 Mathematics - 921.6 Numerical Methods DOI: 10.6041/j.issn.1000-1298.2015.04.007 Database: Compendex 11.Accession number: 20151900832390 Title: Development and performance of rapid compression machine test bench Authors: Zhang, Hongguang1 ; Liu, Hao1; Li, Jiachen1; Zhao, Guangyao1; Yao, Baofeng1; Wang, Yan1 Author affiliation: 1 College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, China Corresponding author: Zhang, Hongguang Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 289-295 and 350 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: A rapid compression machine test bench was developed for studying the combustion characteristic of alternative fuel, and the compression performance tests were carried out. After analyzing the influences of the factors such as hydraulic buffer, driven pressure on properties of the rapid compression machine and improving the compression performance, compression speed of the rapid compression machine was higher than 8 m/s and the compressed temperature can be controlled in the range of 650~1 120 K. Combustion performance tests were carried out by using DME-O2-N2 mixtures. The two-stage combustion and two-stage ignition delay time of the mixtures were observed. The two-stage and overall ignition delay times of DME-O2-N2 mixtures were studied under varied compression ratios, compressed temperatures and compressed pressures. Results showed that with the compressed temperature and compressed pressure increased, the first and overall ignition delay times of mixtures were shorten under the same initial pressure. Under a certain compressed temperature, with increasing compressed pressure, the second and overall ignition delay times of mixtures were shorten while the first stage ignition delay time was shorten slightly. Number of references: 19 Main heading: Ignition Controlled terms: Alternative fuels - Combustion - Hydraulic machinery - Mixtures Uncontrolled terms: Combustion characteristics - Combustion performance - Compression performance - Ignition delay time - Performance tests - Rapid compression machine - Test benches - Two stage combustion Classification code: 521.1 Fuel Combustion - 523 Liquid Fuels - 524 Solid Fuels - 632.2 Hydraulic Equipment and Machinery - 802.3 Chemical Operations DOI: 10.6041/j.issn.1000-1298.2015.04.043 Database: Compendex 12.Accession number: 20151900832362 Title: Effect of mulching on salinized soil freezing and thawing characteristics and autumn irrigation quality Authors: Liang, Jiancai1 ; Shi, Haibin1; Li, Ruiping1 ; Ni, Dongning1; Xu, Zhao1; Zheng, Qian1 Author affiliation: 1 Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Huhhot, China Corresponding author: Li, Ruiping Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 98-105 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The objective of this paper is to discuss the effects of mulching methods on freezing and thawing characteristics of salinized soil and the autumn irrigation quality in cold-drought-salt irrigation district. The field freezing and thawing experiments were conducted with the mulched salinized soil in Hetao Irrigation District. The experiments included five treatments: chopped maize straw 0.9 kg/m2 (F0.9), chopped maize straw 0.6 kg/m2 (F0.6), whole maize straw (YZ), plastic film (DM) and no mulching (CK). The results showed that the heat transport capability of different soil layers was affected by surface mulching after autumn irrigation. Mulching affected the process of soil freezing and thawing and changed the response correlation of the soil frozen depth to the negative accumulated temperature. The soil frozen depth variability during the freezing period can be assessed and predicted by the available negative cumulative air temperature. Results revealed that all mulching treatments improved the soil water storage in the maize sowing time for following year at depth of 0~10, 0~40 and 0~120 cm significantly compared with CK. The soil salinity in the surface layer (0~10 cm) and plough layer (0~40 cm) was drastically lower than that of CK. The salt control effect of whole maize straw YZ was superior to the other treatments. The suitable sowing date of spring maize under plastic film mulching was advanced by 7 d relative to CK, while the straw mulched date was delayed by 6~7 d. Mulching measures improved the maize seedling emergence rate significantly, the emergence rate of maize of YZ and F0.9 were considerably higher than F0.6 and DM. The results could be used to guide the research of autumn irrigation scheduling under mulching situations in Hetao Irrigation District. Number of references: 22 Main heading: Soils Controlled terms: Freezing - Grain (agricultural product) - Irrigation - Plastic films - Scheduling - Soil mechanics - Soil moisture - Thawing Uncontrolled terms: Freezing-thawing - Hetao irrigation districts - Mulching - Negative temperatures - Saline-alkali soils Classification code: 483.1 Soils and Soil Mechanics - 817.1 Polymer Products - 821.3 Agricultural Methods - 821.4 Agricultural Products - 822.2 Food Processing Operations - 912.2 Management DOI: 10.6041/j.issn.1000-1298.2015.04.015 Database: Compendex 13.Accession number: 20151900832397 Title: Efficient condensation parallel computing method for finite element structural analysis based on sparse storage scheme Authors: Miao, Xinqiang1 ; Jin, Xianlong1 ; Ding, Junhong2 Author affiliation: 1 School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai, China 2 Shanghai Supercomputer Center, Shanghai, China Corresponding author: Jin, Xianlong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 338-343 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: An efficient condensation parallel computing method for finite element structural analysis was proposed based on the sparse storage techniques and direct sparse solvers. In the proposed method, the process of condensation was converted to the process of solving a series of linear equations, and then the linear equations were solved with a direct sparse solver. It can avoid the storage and computation of many zero elements within the bandwidth in the traditional parallel computing method with variable bandwidth format condensation. Therefore, the memory space can be greatly saved and the amount of computation can be effectively reduced. Finally, the experiment of the finite element numerical simulation for an engine crankshaft was used to validate the proposed method. Test results showed that, compared with the conventional parallel computing method with variable bandwidth format condensations, the proposed parallel computing approach with sparse storage format condensation could considerably save memory space and significantly improve computational efficiency. The larger the size of each subdomain, the effect of the proposed method on aspects of saving memory space and improving computational efficiency was more obvious. The proposed method can be applied to many industrial areas such as aerospace, automobile, energy, civil and architecture to significantly improve the efficiency of engineering design and analysis. Number of references: 18 Main heading: Finite element method Controlled terms: Bandwidth - Computational efficiency - Condensation - Crankshafts - Linear equations - Numerical methods - Structural analysis Uncontrolled terms: Finite element numerical simulation - Finite element structural analysis - High performance computing - Parallel com- puting - Sparse solvers - Sparse storage formats - Storage technique - Variable bandwidths Classification code: 408.1 Structural Design, General - 601.2 Machine Components - 716.1 Information Theory and Signal Processing - 802.3 Chemical Operations - 921 Mathematics - 921.6 Numerical Methods DOI: 10.6041/j.issn.1000-1298.2015.04.050 Database: Compendex 14.Accession number: 20151900832367 Title: Spatial variability of soil nitrogen and its influential factors in Qionghai Basin Authors: Hu, Yufu1 ; Deng, Liangji1; Xiao, Haihua1; Shu, Xiangyang1; Huang, Chengyi1; Luo, Lanfang1 Author affiliation: 1 College of Resources and Environment, Sichuan Agricultural University, Chengdu, China Corresponding author: Hu, Yufu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 132-140 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Soil nitrogen is necessary nutrient elements for plant in agricultural ecosystem, and excessive nitrogenous fertilizer is one of the main reasons of rural surface source pollution and water eutrophication. Therefore, understanding the spatial variability of soil nitrogen is vital for agricultural production and ecological environment protection. Qionghai lake is the second largest inland plateau freshwater lake of Sichuan Province. And it is important conservation areas for drinking water and nature reserve. Presently the water quality of Qionghai lake was mesotrophic status. Excessive nitrogen from rural surface source pollution was one of the main pollution factors. In this research, 386 soil sample points were selected by using random sampling method in Qionghai Basin, and soil physical and chemical properties were analyzed. Furthermore, spatial variability of soil nitrogen in the surface layer of this region was analyzed by using the geostatistics and GIS method, and its influential factors were also analyzed by means of variance analysis and buffer analysis. The results showed that the contents of soil total nitrogen (TN) and available nitrogen (AN) were (1.85±0.51) g/kg and (138.5±47.7) mg/kg, respectively. Variable coefficients of TN and AN were 27.52% and 32.24%, respectively, which belonged to a moderate level. Geostatistical analysis suggested that the spatial autocorrelations of soil TN and AN were moderate level, and random factors played a more important role in spatial variability than structural factors. The spatial variability of soil TN and AN were anisotropic, and obvious in northeast-southwest direction. TN and AN in the area were distributed in band and patches. Regions with high soil TN and AN contents were mainly distributed in southeast suburbs of Xichang City, and decreased gradually to north, east and south. Regions with low soil TN and AN contents were mainly distributed in north lakeshore zone of Qionghai lake. Spatial variability of soil TN and AN was significantly influenced by land use types, soil parent materials, soil textures, soil pH values as well as distributions of citiy, town, river and Qionghai lake. There was no significant correlation between spatial variability of soil TN and AN contents and roads. Number of references: 21 Main heading: Soils Controlled terms: Agriculture - Chemical analysis - Ecology - Ecosystems - Eutrophication - Factor analysis - Geographic information systems - Lake pollution - Lakes - Land use - Nitrogen - Nitrogen fertilizers - Pollution - Potable water - River pollution - Rural areas - Water pollution - Water quality Uncontrolled terms: Agricultural productions - Buffer analysis - Ecological environment protections - Geo-statistics - Soil nitrogen - Soil physical and chemical properties - Spatial autocorrelations - Spatial variability Classification code: 403 Urban and Regional Planning and Development - 407 Maritime and Port Structures; Rivers and Other Waterways - 444 Water Resources - 453 Water Pollution - 453.2 Water Pollution Control - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 723.3 Database Systems - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics DOI: 10.6041/j.issn.1000-1298.2015.04.020 Database: Compendex 15.Accession number: 20151900832008 Title: Optimum design of parallel mechanism based on kinematics distribution performance Authors: Zhang, Lijie1, 2 ; Guo, Fei1, 2; Li, Yongquan2; Ma, Yalei1, 2 Author affiliation: 1 Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control, Yanshan University, Qinhuangdao, China 2 Key Laboratory of Advanced Forging & Stamping Technology and Science, Ministry of Education, Yanshan University, Qinhuangdao, China Corresponding author: Zhang, Lijie Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 365-371 and 337 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: According to the requirement of a given parallel mechanism end actuator and to make sure that kinematics transmission performance of each branch is relatively better in optimum design of its structure parameters, local and global motion (speed), force and power distribution performance indicators were defined by using the character of dispersion, which reflected the ability of branch to share the load requirements. For a single drive branch power output, the effect of speed and force was discussed which were both variable physical quantities on power, and the movement and force coefficient were defined. The workspace of parallel mechanism was analyzed by using those parameters. Finally the 3-RPS parallel mechanism for attitude adjustment components was used as an example. And a detailed solution to the above indicators was developed. Performance atlas in the modified design space was overlaid, the structural parameters of the mechanism were optimized and the corresponding workspace was found out. The motion, force and power distribution performance indicators can be further applied to the performance analysis of other parallel mechanisms, as well as to guide optimization design of parameters. Each branch of the parallel mechanism obtained through this optimization method has good power, motion and force transmission performance. This sets the foundation for the kinematics and dynamics analysis of parallel mechanism. Number of references: 19 Main heading: Power quality Controlled terms: Benchmarking - Design - Kinematics - Mechanisms Uncontrolled terms: Distribution index - Kinematics and dynamics analysis - Optimum designs - Parallel mechanisms - Performance analysis - Performance atlas - Performance indicators - Transmission performance Classification code: 408 Structural Design - 601.3 Mechanisms - 706.1.2 Electric Power Distribution - 912 Industrial Engineering and Management - 913 Production Planning and Control; Manufacturing - 931.1 Mechanics DOI: 10.6041/j.issn.1000-1298.2015.04.054 Database: Compendex 16.Accession number: 20151900832394 Title: Multi-objective bat algorithm based on decomposition Authors: Wang, Yahui1 ; Jia, Chenhui2; Zhao, Renpeng1 Author affiliation: 1 College of Mechanical Engineering, North China University of Water Resources and Electric, Zhengzhou, China 2 College of Mechatronics Engineering, Henan University of Science and Technology, Luoyang, China Corresponding author: Wang, Yahui Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 316-324 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The bat algorithm was integrated into decomposition mechanism on the basis of its evaluation and a multi-objective bat algorithm based on decomposition (MOBA/D) was proposed. In order to improve the algorithm diversity, the differential evolutionary strategy was introduced into MOBA/D. The performances of MOBA/D on 14 multi-objective optimization problems were tested, which included family benchmark functions of LZ-09 and ZDT with different neighborhood scales effect on the performance of the algorithm. The result indicated that MOBA/D had the best performance with neighborhood size of 20. Compared with MOEA/D-DE and NSGA-II, the simulation results showed that MOBA/D can obtain a more uniform distribution of Pareto solution set and better convergence as well as diversity than those of state-of-the-art multi-objective metaheuristics. For further performance analysis of MOBA/D on constraint problem, the optimization design of sliding bearing was solved to demonstrate the feasibility and effectiveness. The good performance on convergence and diversity of the obtained Pareto set demonstrated that MOBA/D was suitable for engineering practice, which was an effective way for solving complex and high dimensional multi-objective optimization problems. Number of references: 25 Main heading: Multiobjective optimization Controlled terms: Algorithms - Bearings (machine parts) - Benchmarking - Evolutionary algorithms - Optimization Uncontrolled terms: Bat algorithms - Decomposition mechanism - Differential Evolution - Differential evolutionary - Engineering practices - Multi-objective metaheuristics - Multi-objective optimization problem - Sliding bearing Classification code: 601.2 Machine Components - 723 Computer Software, Data Handling and Applications - 912 Industrial Engineering and Management - 913 Production Planning and Control; Manufacturing - 921 Mathematics - 921.5 Optimization Techniques DOI: 10.6041/j.issn.1000-1298.2015.04.047 Database: Compendex 17.Accession number: 20151900832359 Title: Analysis and assessment of water-saving project of Hetao Irrigation District in Inner Mongolia Authors: Qu, Zhongyi1 ; Yang, Xiao1; Huang, Yongjiang1 Author affiliation: 1 Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Huhhot, China Corresponding author: Qu, Zhongyi Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 70-76 and 112 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The net water diversion of agriculture in Hetao Irrigation District was studied. Based on the data during 1982 to 2012 in Hetao Irrigation District, the characteristics of the net water diversion variability in 31 years were analyzed by using several statistic methods, such as ANOM, ANOVA, correlation analysis, time series analysis and survival analysis. In addition, the impact of annual precipitations and water-saving engineering projects was analyzed by the progress of Hetao Irrigation District developmental history. The forecasted net water diversion in Hetao Irrigation District would be about 44.5×108 m3 in 2013, 44.18×108 m3 in 2014 and 43.86×108 m3 in 2015 by the time series analysis method. In current water-saving engineering project, the forecasted net water diversion would be from 35×108 m3 to 55×108 m3 by the survival analysis method. The net water diversion was influenced sharply by annual precipitation (more than 211. 76 mm, namely wet years) and water-saving engineering project. These two factors had a negative correlation with the net water diversion. Finally, the relationship between net water diversion and total investment of water-saving engineering project was discussed. The results provided an important foundation for the management of sustainable development in Hetao Irrigation District. Number of references: 10 Main heading: Time series analysis Controlled terms: Bioinformatics - Climate change - Flood control - Forecasting - Harmonic analysis - Investments - Irrigation - Professional aspects - Time series - Water conservation Uncontrolled terms: Annual precipitation - Correlation analysis - Engineering project - Hetao irrigation districts - Negative correlation - Survival analysis - Water - savings - Water diversions Classification code: 444 Water Resources - 451 Air Pollution - 454.1 Environmental Engineering, General - 821.3 Agricultural Methods - 901.1 Engineering Professional Aspects - 903 Information Science - 911.2 Industrial Economics - 921.6 Numerical Methods - 922.2 Mathematical Statistics DOI: 10.6041/j.issn.1000-1298.2015.04.012 Database: Compendex 18.Accession number: 20151900832377 Title: Progress in infant formula milk powder Authors: Wang, Songping1 ; Ren, Fazheng2 ; Luo, Jie2; Peng, Haixin2; Wang, Yuhan2 Author affiliation: 1 Kexin College, Hebei University of Engineering, Handan, China 2 Key Laboratory of Functional Dairy, Ministry of Education, China Agricultural University, Beijing, China Corresponding author: Ren, Fazheng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 200-210 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Infant formula milk powder is very important for infants whose mother cannot or does not want to breastfeed. There is a growing need for infant formula milk powder market in China, however, the research of basic nutrition and process technology is relative backwardness. The domestic and abroad research progresses about nutrition of infant formula milk powder were introduced by analyzing the breast milk nutrient profile, standard of formula and the development of powder composition. By comparing the dry process and wet process with their effects on powder functionality, the progresses on the process technology of infant formula milk powder were discussed. The hazard analysis was also discussed to better control the quality of infant formula milk powder. A general overview of the selection of formula composition, process technology and the direction of industrial development was provided. Strengthening the basic research on breast milk nutrition, improving the differentiation among products and developing the infant formula which was mostly close to the Chinese breast milk were the key to the future development of China's infant milk powder. Number of references: 83 Main heading: Nutrition Controlled terms: Quality control - Shotcreting Uncontrolled terms: Dry mixes - Humanized milk - Industrial development - Infant milk powder - Milk powder - Nutritional basic - Powder composition - Process Technologies Classification code: 412 Concrete - 461.7 Health Care - 913.3 Quality Assurance and Control DOI: 10.6041/j.issn.1000-1298.2015.04.030 Database: Compendex 19.Accession number: 20151900832392 Title: Attitude measurement system for excavator's manipulator based on vision measurement Authors: Wang, Haibo1 ; Zou, Hailong1; Zhang, Ruzhao1 Author affiliation: 1 School of Mechanical Engineering, Southwest Jiaotong University, Chengdu, China Corresponding author: Wang, Haibo Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 302-308 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: An attitude measuring method for excavator's manipulator based on vision measurement was proposed. Using the industrial camera to grab the perspective images of the manipulator, a saddle point detection was adopted to detect the man-made targets which was fixed on every arm of the excavator. Then the fixed geometric dimensioning between two targets was used as a constraint condition to select the saddle point in targets, and the attitude angle of the corresponding arm can be derived from the saddle point coordinates. The image detection area was reduced through anticipation of target movement and the algorithm processing speed was improved. Experiment results showed that compared with the original displacement sensor system installed on the excavator, the measured deviations of dynamic attitude angle for boom and arm were less than 1 degree and 2 degrees, respectively. The average processing time of this method for each manipulator movement frame was within 100 ms. And the feasibility of this method for measuring excavator manipulator's attitude was verified. Number of references: 18 Main heading: Construction equipment Controlled terms: Excavation - Excavators - Image analysis - Industrial manipulators - Manipulators Uncontrolled terms: Attitude angle - Attitude measurement - Constraint conditions - Displacement sensor systems - Perspective image - Saddle point - Target movements - Vision measurement Classification code: 405.1 Construction Equipment - 405.2 Construction Methods - 731.5 Robotics - 731.6 Robot Applications - 741 Light, Optics and Optical Devices DOI: 10.6041/j.issn.1000-1298.2015.04.045 Database: Compendex 20.Accession number: 20151900832368 Title: Estimating velocity of water flow within gravel layer by different tracer methods Authors: Chen, Liyan1 ; Lei, Tingwu1 ; Dong, Yuequn1; Yan, Yan1 Author affiliation: 1 College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China Corresponding author: Lei, Tingwu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 141-146 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Mountainous soils often contain large amounts of gravels which impact rainfall infiltration, runoff and soil erosion. The flow velocity within gravels is of great importance for research of soil erosion process in rocky mountainous areas. Dye tracer method was commonly used to measure the leading edge velocity. The gravels of about 2 cm in diameter were used to fill to a thickness of about 5 cm in a flume of 4 m long, 15 cm wide and 50 cm high. Five sensors were used to measure the electrolyte conductivity change process at 0.3, 0.6, 0.9, 1.2 and 1.5 m from the solute injector under three flow rates of 3, 6 and 12 L/min and three slope gradients of 4°, 8° and 12°. The peak, mean and leading edge velocities were computed before comparisons were made with those measured by using dye tracer method. The results showed that under different conditions, flow velocity was not significantly affected by discharge rate, but notably affected by slope. With the increase in slope, flow velocity increased from 0.031 m/s to 0.070 m/s. The peak velocities were 0.81~0.83 times of the leading edge velocity, regardless of the effect of slope and flow rate. Mean velocities were about the same as the peak velocities, which were 0.68~0.78 times of the leading edge velocities and increased with distance increasing. The ratio of mean velocity and leading edge velocity can be also used to calculate the flow velocity within gravels measured by dye tracer method. The method should be useful to understand the hydrodynamics of water flow within gravel layers. Number of references: 23 Main heading: Velocity Controlled terms: Erosion - Flow of water - Flow rate - Flow velocity - Gravel - Hydraulics - Soils Uncontrolled terms: Discharge rates - Electrolyte conductivity - Gravel layers - Mean velocities - Mountainous area - Peak velocities - Rainfall infiltration - Tracer methods Classification code: 407 Maritime and Port Structures; Rivers and Other Waterways - 483 Soil Mechanics and Foundations - 631 Fluid Flow - 631.1.1 Liquid Dynamics - 632.1 Hydraulics - 931.1 Mechanics DOI: 10.6041/j.issn.1000-1298.2015.04.021 Database: Compendex 21.Accession number: 20151900832386 Title: Prediction of soil moisture content in air-drying loess using spectral data Authors: Liu, Xiuying1, 2 ; Wang, Li1; Song, Rongjie1; Liu, Miao1; Chang, Qingrui1 Author affiliation: 1 College of Natural Resources and Environment, Northwest A&F University, Yangling; Shaanxi, China 2 Agronomy College, Henan University of Science and Technology, Luoyang, China Corresponding author: Chang, Qingrui Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 266-272 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: 129 loess soil samples taken from the field in Qian County of Shaanxi Province in 2014 were chosen as objects to build the inversion model between soil moisture content and spectra. The spectra and gravimetric moisture content of soil samples were measured during the process of soil air drying, and the relationship between spectra and soil moisture content was analyzed. The spectral predictive models of soil moisture content were established by using the linear regression and exponential analysis. Results showed that the biggest correlation coefficients and absorption depth bands located in 570, 1 460, 1 960 nm and 490, 1 460, 1 960 nm in the region of 400~1 340, 1 460~1 790, 1 960~2 390 nm, respectively. The linear relationship between spectral characteristic indexes and moisture content was better than the index relationship. The linear models were optimum models for predicting moisture content of loess by using characteristic band (C1980) and absorption depth (D1980 and D1480) as independent variables. The calibration and validation coefficient of determination R2 and residual prediction deviation (RPD) were higher than 0.92 and 2.5, respectively, and the root mean square error (RMSE) was less than 2.5%. These results showed that the moisture content of natural soil samples can be predicted rapidly by using spectral reflectance during the soil drying process. The study can provide a reference for real-time and rapid soil moisture content monitoring and soil moisture quantitative inversion in large area by using remote sensing technology. Number of references: 29 Main heading: Soil moisture Controlled terms: Drying - Forecasting - Mean square error - Moisture - Moisture control - Moisture determination - Remote sensing - Sediments - Soil surveys - Soils - Solar dryers Uncontrolled terms: Air drying - Calibration and validations - Coefficient of determination - Correlation coefficient - Predictive modeling - Remote sensing technology - Root mean square errors - Spectral characteristics Classification code: 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 642.1 Process Heating - 731.1 Control Systems - 801.4 Physical Chemistry - 802.1 Chemical Plants and Equipment - 921 Mathematics - 944.2 Moisture Measurements DOI: 10.6041/j.issn.1000-1298.2015.04.039 Database: Compendex 22.Accession number: 20151900832381 Title: Analysis of microwave drying model and water removing mechanism of ginger slices Authors: Lü, Weiqiao1 ; Han, Qinghua2; Li, Shujun2 ; Zhou, Haijun2; Zhao, Donglin2; Zhu, Weihua3 Author affiliation: 1 College of Engineering, China Agricultural University, Beijing, China 2 Chinese Academy of Agricultural Mechanization Sciences, Beijing, China 3 Shenyang Areo Space Xinyang Quick Freezing Equip. Manuf. Co., Ltd., Shenyang, China Corresponding author: Li, Shujun Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 233-237 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The dehydration process of ginger slices at microwave power of 0.8, 1.2, 1.6 W/g (dry basis) was researched. The moisture content, drying speed and moisture ratios at different stages were calculated. Some drying mathematical models were selected, and by fitting analysis of the moisture ratios, Wang-Singh model can be used for dehydration process of ginger slices by microwave fluidized drying. Through the technology of nuclear magnetic resonance (NMR), the flow characteristics of moisture in ginger slices drying process were studied. A conclusion could be got that the free water can be converted to some uneasy flowing bound water in a short time, the whole drying process was dominated by drying bound water, and at the final stage the bound water was decreased to a certain extent and hydration water content increased, while uneven drying hadn't been eliminated completely in microwave fluidized drying. A theoretical basis for the process control and process optimization of ginger slices microwave drying was provided. Number of references: 9 Main heading: Drying Controlled terms: Dehydration - Fluidization - Food additives - Microwave heating - Microwaves - Moisture - Nuclear magnetic resonance - Optimization - Process control Uncontrolled terms: Bound waters - Dehydration process - Different stages - Flow charac-teristics - Free water - Ginger slices - Microwave drying - Nuclear magnetic resonance(NMR) Classification code: 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 731 Automatic Control Principles and Applications - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 921.5 Optimization Techniques - 932.2 Nuclear Physics DOI: 10.6041/j.issn.1000-1298.2015.04.034 Database: Compendex 23.Accession number: 20151900832374 Title: Preparation and performance optimization of clay-based porous ceramics used in subsurface irrigation Authors: Cai, Yaohui1 ; Wu, Pute1, 2 ; Zhu, Delan1, 2; Li, Xiangming1, 2; Zhang, Lin2; Chen, Junying1, 2 Author affiliation: 1 College of Water Resources and Architecture Engineering, Northwest A&F University, Yangling; Shaanxi, China 2 Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling; Shaanxi, China Corresponding author: Wu, Pute Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 183-188 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Subsurface irrigation has been realized by burying pots, pitchers and subsurface porous pipe, but the present preparation process of porous ceramics could not meet the performance requirements of subsurface irrigation emitters. A new preparation process of clay-based porous ceramics used for subsurface irrigation with minimal cost was explored. The effects of the preparation process (shirking temperature, contents and particle size of slag in the green body) on flexural strength, linear shrinkage and open porosity of porous ceramic were discussed. Finally, the optimal preparation process of porous ceramic with high flexural strength, low linear shrinkage and elevated open porosity were selected. The results showed that the sintering temperature and the contents and particle size of slag in the green body were three key factors influencing the properties of porous ceramics. When sintering temperature was 1 075 along with content of slag in the green body between 10% and 30%, the porous ceramics showed the best performance with maximum particle size of 0.613 mm. Flexural strength of porous ceramic was 9.0~11.0 MPa with open porosity of 36.8%~44.8% and the linear shrinkage was 3.8%~4.7%. Therefore, the clay-based porous ceramic could be the appropriate material for subsurface irrigation emitter. Number of references: 22 Main heading: Clay Controlled terms: Bending strength - Ceramic materials - Irrigation - Particle size - Porosity - Shrinkage - Sintering - Slags - Subirrigation Uncontrolled terms: Appropriate materials - High flexural strength - Open porosity - Performance optimizations - Performance requirements - Porous ceramics - Preparation process - Sintering temperatures Classification code: 406 Highway Engineering - 412 Concrete - 413 Insulating Materials - 421 Strength of Building Materials; Mechanical Properties - 812.1 Ceramics - 812.2 Refractories - 821.3 Agricultural Methods - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science DOI: 10.6041/j.issn.1000-1298.2015.04.027 Database: Compendex 24.Accession number: 20151900832396 Title: Solution region synthesis method of eight-bar linkages for 4R open chain Authors: Cui, Guangzhen1 ; Han, Jianyou1 ; Yang, Tong1 Author affiliation: 1 School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China Corresponding author: Han, Jianyou Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 331-337 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: For the dimension synthesis of eight-bar linkages for 4-position, a solution region synthesis method was presented. Firstly, the solution curves meeting the requirements were obtained according to the specified 4-position 4R open chain. The solution region was set up according to feasible sections of solution curves. Secondly, the linkage with defects was removed from the solution region by using defects identification method of eight-bar linkages. Finally, the feasible solution region was built and practical engineering requirements were considered and imposed. The eight-bar linkages from the feasible solution region, which met the requirements, can be picked out rapidly and accurately by designers. The problem of dimension synthesis of eight-bar linkages for 4-position was solved effectively by the solution region synthesis method and the eight-bar linkages could be widely applied in reality. The synthesis process of eight-bar linkages for 4-position was illustrated by the example. Number of references: 20 Main heading: End effectors Controlled terms: Chains - Defects Uncontrolled terms: Bar linkages - Feasible solution - Identification method - Open chain - Practical engineering - Synthesis method - Synthesis process Classification code: 423 Non Mechanical Properties and Tests of Building Materials - 602.1 Mechanical Drives - 731.5 Robotics - 951 Materials Science DOI: 10.6041/j.issn.1000-1298.2015.04.049 Database: Compendex 25.Accession number: 20151900832355 Title: Design and experiment of high specific speed centrifugal submersible sewage pump Authors: Zhu, Rongsheng1 ; Cao, Liang1; Long, Yun1; Zhu, Dongxin2; Fu, Qiang1; Wang, Zhenwei1 Author affiliation: 1 Technical and Research Center of Fluid Machinery Engineering, Jiangsu University, Zhenjiang, China 2 College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China Corresponding author: Zhu, Rongsheng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 47-52 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: To improve the performance of high specific speed centrifugal non-clogging submersible sewage pump, the 350QW 1500-16-90 sewage pump was designed by using unequal head hydraulic design method and traditional equal head hydraulic design method. Three different optimization plans were proposed and CFD software ANSYS CFX was applied to analyze the interior flow field of each plan under different conditions, the performance was predicted and the best plan was selected to test by internal flow characteristics and performance curves. It was demonstrated that using unequal head hydraulic design method can reduce the area of low pressure of impeller working face and backflow, central runner had the lowest relative velocity so that blade outlet of the pump had a uniform static pressure and velocity distribution. The predicted curve obtained by CFD technology and performance curves obtained by experiment of head and efficiency had the consistent variation. There was no saddle zone and overload phenomenon, which indicated that it satisfied the design requirements and the numerical simulation was accurate and it had guiding significance for the high specific speed sewage pump design. The absolute value of head curve slope increased with the increase of flow, the maximum efficiency point was occurred at 1 699.93 m3/h and maximum efficiency was 80.256%. Maximum efficiency point shifted to the large flow, where the efficiency curves changed gently, 0.9Q~1.3Q was high efficiency area which was conformed to be the operating characteristics of the sewage pump running at high flow conditions, it was helpful to improve the current situation of high energy consumption at sewage treatment for using unequal head hydraulic design method. Number of references: 17 Main heading: Design Controlled terms: Centrifugation - Computational fluid dynamics - Computer simulation - Curve fitting - Energy utilization - Experiments - Numerical methods - Numerical models - Pumps - Sewage pumps - Sewage treatment - Software testing - Submersibles - Water piping systems Uncontrolled terms: Consistent variation - Design method - Guiding significances - High energy consumption - High flow conditions - High specific speed - Internal flow characteristics - Operating characteristics Classification code: 408 Structural Design - 452.2 Sewage Treatment - 525.3 Energy Utilization - 618.2 Pumps - 674.1 Small Marine Craft - 723.5 Computer Applications - 802.1 Chemical Plants and Equipment - 802.3 Chemical Operations - 901.3 Engineering Research - 921 Mathematics - 921.6 Numerical Methods DOI: 10.6041/j.issn.1000-1298.2015.04.008 Database: Compendex 26.Accession number: 20151900832007 Title: Linearized robust registration algorithm based on m-estimation Authors: Tan, Gaoshan1, 2 ; Zhang, Liyan1 ; Liu, Shenglan1; Zhang, Tao2 Author affiliation: 1 College of Mechanical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China 2 School of Mathematics and Physics, Anhui University of Technology, Maanshan, China Corresponding author: Zhang, Liyan Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 360-364 and 343 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Rapid and wide application of the complex surface in modern manufacturing makes new demands of the registration techniques on complex surface. Although significant progress has been made in complex surface registration, it remains a difficult problem in some situation. For a complex part with multiple freeform surfaces, the precision of measurement points often exists different in different surface regions due to a variety of measurement methods. Meanwhile, the manufacture precision in different regions is also not the same in complex manufacture process. Problems of registration on complex surface, have become increasingly prominent and new methods are bound to be found. Robust principle was generalized to the complex surface registration in which the precision difference existed in different surface regions. A robust registration was presented based on M-estimation. The effect of low precision measured data was weakened for the registration result by M-estimation functions. But the solving efficiency of the model was low due to the highly nonlinear and piecewise of the objective function. A good initial position was easily available with current registration method, and the error functions were linearly approximated by Taylor expansion when the rotation transform was slight. A linear registration model was found and the efficiency was improved. An approximation of the rotation matrix based on the minimization of Fibonacci norm was adopted in each iteration. Both theoretical and experimental results confirmed the stabilization and efficiency. Number of references: 16 Main heading: Image enhancement Controlled terms: Algorithms - Efficiency - Iterative methods - Linearization - Manufacture - Mathematical transformations Uncontrolled terms: Least Square - M-estimation - Manufacture process - Registration - Registration methods - Registration techniques - Robust estimation - Rotation transforms Classification code: 723 Computer Software, Data Handling and Applications - 741 Light, Optics and Optical Devices - 913.1 Production Engineering - 913.4 Manufacturing - 921 Mathematics DOI: 10.6041/j.issn.1000-1298.2015.04.053 Database: Compendex 27.Accession number: 20151900832365 Title: Spatial variability of soil thermal parameters and its fitting method Authors: Wang, Weihua1 ; Li, Jianbo1; Wang, Shuo2; Wang, Quanjiu3, 4 ; Zhou, Guanglin3 Author affiliation: 1 Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, China 2 Shangluo Water Resources Bureau, Shangluo, China 3 Institute of Water Resources and Hydrologic Engineering, Xi'an University of Technology, Xi'an, China 4 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling; Shaanxi, China Corresponding author: Wang, Quanjiu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 120-125 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: There are some research difficulties and highlights in analyzing spatial variation in recent years, such as how to choose advanced methods, how to make efficient and reasonable experimental designs, how to normalize field sampling program process, and how to select representative sampling points. In view of the above mentioned issues, a research on spatial variable of soil thermal parameters on basin scale in Jinghui Canal Irrigation District, Shaanxi Province was conducted by combining RS, GPS and GIS technology. The results showed that soil thermal capacity, thermal diffusion and thermal conductivity displayed moderate variation in the selected regional scale. Thermal diffusion and thermal conductivity displayed a stronger spatial heterogeneity than soil thermal capacity, which showed a relative weaker one. Furthermore, a strong spatial dependence was found among the above three parameters. The optimum fitting models for soil thermal capacity, thermal diffusion and thermal conductivity were exponential model, spherical model and Gaussian model, respectively. And the sample spacings of above three models were recommended to be 2.67, 3.68 and 2.76 km, respectively. Meanwhile, the best sampling spacing of soil thermal parameters in this region was recommended to be 3 km. A simple fitting formula for soil thermal parameters determined by basic parameters of soil physics was established based on describing the spatial variability of soil thermal parameters. It was proved to be a good applicability with R2>0.80 after verifying. It indicated that quantization analysis on complex spatial variability of soil thermal parameters could be well achieved based on the introduced method. Number of references: 14 Main heading: Thermal conductivity Controlled terms: Design - Diffusion - Soil mechanics - Soils - Thermal diffusion Uncontrolled terms: Basin scale - Jinghui canal irrigation districts - Prediction model - Quantization analysis - Representative sampling - Soil thermal parameters - Spatial heterogeneity - Spatial variability Classification code: 408 Structural Design - 483.1 Soils and Soil Mechanics - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids DOI: 10.6041/j.issn.1000-1298.2015.04.018 Database: Compendex 28.Accession number: 20151900832391 Title: Parameter identification of intake port fuel film dynamic model for gasoline engine Authors: Zheng, Taixiong1 ; Zhou, Kejun2; Li, Yongfu2; Li, Xuanzheng2 Author affiliation: 1 School of Advanced Manufacturing Engineering, Chongqing University of Posts and Telecommunications, Chongqing, China 2 School of Automation, Chongqing University of Posts and Telecommunications, Chongqing, China Corresponding author: Zheng, Taixiong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 296-301 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Accurate air-fuel ratio control is the key element for fuel economy low emissions and good driveability of spark ingnition engine. In order to more accurately identify the fuel film model parameter and achieve precise control of air-fuel ratio, the film identification equation based on fuel film dynamic model was built under the consideration of model error and random error. According to recursive least squares, the parameter estimation with weighted matrix expression was got, then the weighted matrix was solved using Markov estimation and the estimated value of optimal film parameter was got consequently. An engine model was set up using GT-power, and air fuel ratio, mass injection flow engine speed and air mass flow were obtained by using sampling experiment. Parameter identification applying the proposed algorithm and the least squares were conducted at 1 000~3 500 r/min with throttle opened from 5%~75%, respectively. Meanwhile, the identification results were compared with the calibration value. The results showed that the deposition coefficient X of fuel reduced and evaporation time constant τ of film quality increased with increase of throttle opening degree when speed was the same, and X, τ decreased as speed increasing when throttle opening degree was the same. Compared with the least squares algorithm, more accurate identification result can be got by using the proposed algorithm. Number of references: 20 Main heading: Parameter estimation Controlled terms: Algorithms - Dynamic models - Engines - Fuel economy - Fuels - Identification (control systems) Uncontrolled terms: Air-fuel ratio control - Calibration values - Fuel film model - Least squares algorithm - Matrix expression - Recursive least square (RLS) - Recursive least squares algorithms - Throttle opening Classification code: 521 Fuel Combustion and Flame Research - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 612 Engines - 731.1 Control Systems - 921 Mathematics DOI: 10.6041/j.issn.1000-1298.2015.04.044 Database: Compendex 29.Accession number: 20151900832388 Title: Aquaculture pathogens detection based on microfluidic system with magnetic isolation Authors: Guo, Jianjiang1, 2 ; Zhang, Rongbiao1 ; Yang, Ning1; Sun, Jian1; Xu, Peifeng1 Author affiliation: 1 School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, China 2 School of Electronic Information and Electrical Engineering, Changzhou Institute of Technology, Changzhou, China Corresponding author: Zhang, Rongbiao Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 277-281 and 308 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Aiming at the problem that the detection of aquaculture pathogens suffers from difficult isolation, time-consuming and low degree of automation, a detecting method of aquaculture pathogens concentration based on microfluidic system with magnetic isolation was proposed. A dedicated microfluidic chip with automatic sample injecting, magnetic isolation and impedance measurement was designed, and the experiment platform based on microfluidic detection system was built. The optimum impedance measurement frequency, magnetic force and target bacteria capture time in the microfluidic system were determined, and as an example of Escherichia coli O157: H7 the performance of the system was experimentally verified. Experiment results showed that compared with plate counting method the proposed method was nearly the same in detection accuracy, and the detection time was decreased from 48 h to 50 min because of no-cultivation. The microfluidic system realized rapid isolation and detection for aquaculture pathogens with increased automation in the prevention of aquaculture disease. Number of references: 15 Main heading: Microfluidics Controlled terms: Aquaculture - Electric impedance measurement - Escherichia coli - Fluidic devices - Magnetism - Pathogens Uncontrolled terms: Detection accuracy - Escherichia coli O157:H7 - Experiment platforms - Impedance measurement - Magnetic isolation - Micro fluidic system - Microfluidic chip - Microfluidic detection Classification code: 461.9 Biology - 631 Fluid Flow - 701.2 Magnetism: Basic Concepts and Phenomena - 732.1 Control Equipment - 821.3 Agricultural Methods - 942.2 Electric Variables Measurements DOI: 10.6041/j.issn.1000-1298.2015.04.041 Database: Compendex 30.Accession number: 20151900832383 Title: Identification of osmotolerant yeast in apple juice concentrate from Shaanxi Province Authors: Wang, Huxuan1 ; Yue, Tianli1; Hu, Zhongqiu1; Niu, Chen1 Author affiliation: 1 College of Food Science and Engineering, Northwest A&F University, Yangling; Shaanxi, China Corresponding author: Wang, Huxuan Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 246-251 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to study osmotolerant yeasts which are capable of causing spoilage for apple juice concentrate, the yeasts present in apple juice concentrate collected from apple juice processing plants in Shaanxi Province were isolated and purified by using osmotic YPD media. The sugar-tolerance of different yeast isolates was assayed. The colony morphology, cell morphology and physiological characteristics were studied and the phylogenetic tree based on 26S rDNA sequence analysis was constructed to determine the genetic location of isolates. Except the isolate N18 which was identified as strain of Candida tropicalis, all the other isolates belonged to Zygosaccharomyces rouxii. All the isolated strains of Z. rouxii were capable of growing in 900 g/L glucose and apple juice concentrate, displaying better sugar-tolerance ability and greater harm to the quality of apple juice concentrate than isolate of C. tropicalis which showed sugar-tolerance of 750 g/L glucose and no visible growth in apple juice concentrate. The results suggested that strains of Z. rouxii might pose a threat to the quality of apple juice concentrate, and it was needed to be controlled in the production line of apple juice concentrate. Number of references: 19 Main heading: Fruit juices Controlled terms: Candida - Fruits - Glucose - Morphology - Quality control - Yeast Uncontrolled terms: 26S rDNA - Apple juice concentrates - Candida tropicalis - Colony morphology - Osmo-tolerant yeast - Phylogenetic trees - Physiological characteristics - Z. rouxii Classification code: 461.9 Biology - 821.4 Agricultural Products - 822.3 Food Products - 913.3 Quality Assurance and Control - 951 Materials Science DOI: 10.6041/j.issn.1000-1298.2015.04.036 Database: Compendex 31.Accession number: 20151900832372 Title: Distribution patterns of surface water body diversity at different grain sizes Authors: Ren, Yuanyuan1 ; Zhang, Xuelei1, 2 Author affiliation: 1 School of Water Conservancy and Environment, Zhengzhou University, Zhengzhou, China 2 Institute of Natural Resources and Eco-environment, Zhengzhou University, Zhengzhou, China Corresponding author: Zhang, Xuelei Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 168-175 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Three case study areas from north, central and south Henan Province in China were selected for applying spatial grain size method to the research of distribution patterns of surface water body diversity. On the basis of summarizing and adapting the previous research methods of surface water body diversity from related references, a new method of space distribution length index (MSHDLI) was put forward. Then all the selected information was further processed to present the effects of different grain sizes, correlativity and effects of grain size between the correlation coefficient of MSHDLI, water network density (RD) and MSHDAI (modified Shannon diversity area index), and scaling relations between the three used indices and parameter, and multiple regression analysis model at a resolution of 1 km×1 km. Results showed that with the increase of spatial grain size, the granularity of the response curves of MSHDLI, RD and MSHDAI belonged to drop type; MSHDLI maintained significant correlativity with RD and MSHDAI with average correlation coefficient of 0.997 and 0.878 (P<0.01), respectively. Effect of grain size of correlation coefficient was significantly positive correlation between MSHDLI, RD and MSHDAI. The fitting function of MSHDLI and RD was logarithmic function, MSHDLI and MSHDAI was polynomial function. Multivariate linear regression model of MSHDLI, RD and MSHDAI indices was also conducted to show that MSHDLI was the dependent variable and RD, MSHDAI were the independent variables. The fitting model showed that MSHDLI and RD, MSHDAI had linear correlationship, and the level of MSHDLI to explain the others was above 95%. To a certain extent, MSHDLI can be a good combination of the indexes of RD and MSHDAI to describe the breadth and the spatial discreteness in surface water resource distributions. Number of references: 20 Main heading: Surface waters Controlled terms: Grain size and shape - Linear regression - Regression analysis - Water resources Uncontrolled terms: Correlativity analysis - Grain size - MSHDLI - Regression model - Scaling relations - Surface water body Classification code: 444 Water Resources - 444.1 Surface Water - 801.4 Physical Chemistry - 922.2 Mathematical Statistics DOI: 10.6041/j.issn.1000-1298.2015.04.025 Database: Compendex 32.Accession number: 20151900832389 Title: Vehicle tire parameter and state estimation under driving situation based on auxiliary particle filter method Authors: Bao, Ruixin1, 2 ; Sabbioni, Edoardo2; Yu, Huilong2; Zhang, Tao2 Author affiliation: 1 School of Mechanical Engineering, Liaoning Shihua University, Fushun, China 2 Department of Mechanical Engineering, Politecnico di Milano, Milano, Italy Corresponding author: Bao, Ruixin Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 282-288 and 301 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Individual tire magic formula parameter is traditionally derived from expensive equipment in laboratory which needs a large number of experimental data. And then the parameter is transferred to vehicle model at a design stage to simulate the vehicle handling behavior. The main source of uncertainty in this type of models lies in the tire-road interaction due to high nonlinearity. Proper estimation of tire model parameters is important for obtaining reliable results. A vehicle dynamics system containing constant noise and non-linear model was established, and the Runge-Kuttta method was used to simulate the model. The parameters were estimated by using auxiliary particle filter through two rounds weighted processes, and the vehicle dynamic parameters such as tire lateral forces could be estimated by using the parameters estimated before. Meanwhile, the field test was done. The measurements under several standard handling maneuvers (step-steer, double-lane-change, etc.) were presented, and the results showed that the proposed algorithm improved the accuracy of standard particle filter. Number of references: 14 Main heading: Parameter estimation Controlled terms: Airships - Dynamic models - Monte Carlo methods - Research aircraft - Runge Kutta methods - Tires - Vehicles Uncontrolled terms: Auxiliary particle filter - Double lane changes - Driving situations - Expensive equipments - Magic formulas - Parameter and state estimation - Parameters estimated - Tire model parameters Classification code: 432 Highway Transportation - 652.1 Aircraft, General - 652.5 Balloons and Gliders - 731.1 Control Systems - 818.5 Rubber Products - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics DOI: 10.6041/j.issn.1000-1298.2015.04.042 Database: Compendex 33.Accession number: 20151900832348 Title: Automatic control system of seeding depth based on piezoelectric film for no-till planter Authors: Huang, Dongyan1, 2 ; Zhu, Longtu2; Jia, Honglei1 ; Yu, Tingting2 Author affiliation: 1 Key Laboratory of Bionics Engineering, Ministry of Education, Jilin University, Changchun, China 2 College of Information, Jilin Agricultural University, Changchun, China Corresponding author: Jia, Honglei Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 1-8 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Conservation tillage effectively protects the environment. A no-till planter can seed on the straw mulching farmlands, and it is the most important machine in conservation tillage. In order to make sure the consistency of sowing depth, an active seeding depth control system was designed for a no-till planter. The system was consisted of piezoelectric film sensor, a signal processing circuit, a control signal generating circuit and a pneumatic drive system. When planting with a conventional row crop planter which had a plurality of row units mounted on a toolbar, it was necessary to provide a sufficient down force on each row unit to ensure that the seed trench opener was fully penetrated into the soil. Proper down force was also essential to provide proper amount of soil compaction in the side walls of the seed trench. Seeding depth primarily depended on the down force on each row unit. In order to make adjustments to the down force in real time, it was needed to measure the magnitude of the down force on an ongoing basis. The piezoelectric film sensors were used for measuring the deformation of depth limit wheel, the down force of the row unit was monitored in real time according to the deformation of the limit wheel. The piezoelectric film generated charge during rotating of the wheel. The sensor changed the charge into a voltage signal. The voltage signal was processed by low-pass filter and preamplifier circuit in order to eliminate the noise and amplifiy the filter, and then the peak-holding circuit gained the peak voltage value which was sampled by A/D conversion and sent to control signal generating circuit by the wireless transmitter. Wireless receiver received the digital signal which was compared with the present value stored in the microcontroller, if the received signal was less than the present value, the difference between the received signal and the present value formed the control signal. The pneumatic drive system was consisted of air compressors, tank, filters, electric-gas proportional valve and air spring. To provide the necessary down force, an air spring was assembled at the linkage which was mounted in the row unit to the toolbar. Compressed air was generated by the air compressor and stored in the tank, and then the compressed air was filtered to filter out dust and impurities. Pure compressed air was fed to the electric-gas proportional valve; the output of electric-gas proportional valve was connected to the air spring. The output gas pressure of the electric-gas proportional valve was controlled by control signal, the air spring can generate corresponding down force on the unit row. A field experiment was conducted to verify the performance of the seeding depth automatic control system, and the result showed that the seeding depth control system can provide accurate ditching depth and reliable performance of profiling. When the speed of the planter was over 8 km/h, the qualified sowing depth rate of the active seeding depth control system was much better than that of the passive control system. Number of references: 17 Main heading: Air filters Controlled terms: Agricultural machinery - Agriculture - Amplifiers (electronic) - Analog to digital conversion - Automation - Compressed air - Control - Control systems - Deformation - Depth profiling - Gas compressors - Gases - Low pass filters - Piezoelectricity - Pneumatic drives - Pneumatics - Pressure vessels - Process control - Seed - Signal processing - Signal receivers - Soil conservation - Soil mechanics - Springs (components) - Tanks (containers) - Voltage measurement - Wheels Uncontrolled terms: No-till planters - Passive control system - Piezoelectric film - Preamplifier circuit - Reliable performance - Seeding depth - Signal processing circuits - Wireless transmitter Classification code: 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 483.1 Soils and Soil Mechanics - 601.2 Machine Components - 618.1 Compressors - 619.2 Tanks - 632.3 Pneumatics - 632.4 Pneumatic Equipment and Machinery - 701.1 Electricity: Basic Concepts and Phenomena - 703.2 Electric Filters - 713.1 Amplifiers - 716 Telecommunication; Radar, Radio and Television - 716.1 Information Theory and Signal Processing - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 722.4 Digital Computers and Systems - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 801 Chemistry - 802.1 Chemical Plants and Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.2 Physical Properties of Gases, Liquids and Solids - 942.2 Electric Variables Measurements DOI: 10.6041/j.issn.1000-1298.2015.04.001 Database: Compendex 34.Accession number: 20151900832370 Title: Visualized experiment for observing infiltration process affected by preferential flow inside ring infiltrometer Authors: Zhang, Jing1 ; Lei, Tingwu1 ; Hu, Yaqi1; Yan, Jun1; Chen, Tianqin1 Author affiliation: 1 College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China Corresponding author: Lei, Tingwu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 155-160 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Studying the effects of preferential flow on the infiltration process is of great importance to increase the accuracy of measurement. An experimental device was suggested to display water movement process in the soil during infiltration. The device consisted of a disassemble soil container, a halved infiltration ring and see-through container surface made of plexiglass plate. After infiltration ring was hammered into soil inside the container, the soil inside the halved ring was cut radially into two halves with a steel plate, part of soil outside the experimental part of the container was removed and a plexiglass plate was used to cover the soil inside infiltration ring for dynamic visualization infiltration experiment. Then the infiltration process in the soil profile within the ring can be observed. The structure of the device, working principle and its application methodologies were detailed. A series of infiltration experiments were conducted to demonstrate the working procedures of the device with silt loam taken from Beijing. The exemplary soil infiltrability processes were computed based on the water supplied into the ring during the experiments. The dynamic process of wetted area in the soil profile inside the ring indicated that preferential flow not only influenced the initial infiltration process but also affected the total infiltration process. The whole infiltration process was divided into three stages based on the infiltration characteristics produced by wetting soil, which were initial infiltration stage, transitional stage and steady infiltration stage, respectively. Number of references: 20 Main heading: Infiltration Controlled terms: Containers - Display devices - Groundwater flow - Plates (structural components) - Silt - Soils - Testing - Visualization - Wetting Uncontrolled terms: Infiltration process - Infiltrometers - Preferential flows - Test method - Visualization devices Classification code: 408.2 Structural Members and Shapes - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 691 Bulk Handling and Unit Loads - 694 Packaging - 722.2 Computer Peripheral Equipment - 902.1 Engineering Graphics - 931.2 Physical Properties of Gases, Liquids and Solids DOI: 10.6041/j.issn.1000-1298.2015.04.023 Database: Compendex 35.Accession number: 20151900832360 Title: Response of physiological properties and crop water productivity of young apple tree to water and fertilizer Authors: Zhou, Hanmi1 ; Zhang, Fucang1, 2 ; Roger, Kjelgren3; Wu, Lifeng1, 2; Gao, Mingxia1, 2; Li, Zhijun1, 2 Author affiliation: 1 Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling; Shaanxi, China 2 Institute of Water-saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling; Shaanxi, China 3 Department of Plant Soils and Climate, Utah State University, Logan, United States Corresponding author: Zhang, Fucang Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 77-87 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to explore the accurate management mode of water and fertilizer supply for young apple tree in semi-arid region, the bucket cultivation experiment was conducted to study the response mechanism of physiological properties and crop water productivity of two-year-old young apple tree to different water and fertilizer treatments. The treatments consisted of four irrigation levels: 75%~85% (W1), 65%~75% (W2), 55%~65% (W3) and 45%~55% (W4) of field capacity, and three fertilization (N-P2O5-K2O) levels: 0.6-0.6-0.2 (F1), 0.4-0.4-0.2 (F2) and 0.2-0.2-0.2 g/kg (F3) water-free soil. The results showed that relative and saturated water contents and SPAD value of young apple trees' leaves all can reflect the deficit status of soil moisture. The highest and lowest proline were found in F1W4 and F3W1 treatments (that in F1W4 was increased by 440.8% compared with F3W1), and the highest and lowest malonaldehyde were found in F3W4 and F1W1 treatments (that in F3W4 was increased by 167% compared with F1W1), respectively. The highest water use efficiency of leaf (WUE) and crop water productivity (CWP) both appeared in the treatment of F2W2 of which the net photosynthetic rate Pn, transpiration rate Tr and stomatal conductance Gs were decreased by 18.8%, 29.1% and 23.2%, respectively, while WUE was increased by 14.2%, dry mass was decreased by 5.2%, water consumption was also decreased by 16.4% and CWP was increased by 13.4%. WUE can reflect the CWP to some degree and the treatment of F2W2 reached the best water and fertilizer coupling mode. Number of references: 47 Main heading: Fruits Controlled terms: Arid regions - Crops - Fertilizers - Forestry - Photosynthesis - Physiological models - Physiology - Productivity - Soil moisture - Water management - Water supply Uncontrolled terms: Apple trees - Crop water productivity - Net photosynthetic rate - Physiological properties - Stomatal conductance - Transpiration rates - Water productivity - Water use efficiency Classification code: 443 Meteorology - 444 Water Resources - 446 Waterworks - 446.1 Water Supply Systems - 461.1 Biomedical Engineering - 461.9 Biology - 483.1 Soils and Soil Mechanics - 741.1 Light/Optics - 804 Chemical Products Generally - 821.0 Woodlands and Forestry - 821.4 Agricultural Products - 913.1 Production Engineering DOI: 10.6041/j.issn.1000-1298.2015.04.013 Database: Compendex 36.Accession number: 20151900832395 Title: Conformal geometric algebra method for kinematics analysis of spatial parallel mechanisms Authors: Zhang, Zhonghai1, 2 ; Li, Duanling1 Author affiliation: 1 School of Automation, Beijing University of Posts and Telecommunications, Beijing, China 2 Beijing Aerospace Measurement & Control Technology Co., Ltd., Beijing, China Corresponding author: Li, Duanling Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 325-330 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: As a new geometric representation and calculation system, the conformal geometric algebra has been recognized as a research hotspot in recent years. But as a new branch of algebra, the conformal geometric algebra is still in the process of development, especially its application in theory of mechanism is relatively deficient at present. The new geometric algebra method for the kinematics analysis of spatial parallel mechanisms was studied and a conformal geometric algebra method integrating geometric representation and calculation was proposed. With the origin of coordinates on the moving platform describing its position and Euler angles describing its orientation, the conformal geometric algebra expression of an arbitrary point's location on the moving platform in the fixed coordinate system was presented. Then a method to establish kinematics equations for the kinematics analysis of spatial parallel mechanisms was proposed to conduct the forward and inverse kinematics analysis of spatial parallel mechanisms. A 4-UPU parallel mechanism was taken as an example to illustrate the proposed conformal geometric algebra method for kinematics analysis of spatial parallel mechanisms. And a numerical example was given to verify correctness and effectiveness of the proposed approach. The proposed conformal geometric algebra method was a new method for the kinematics analysis of spatial parallel mechanisms by integrating geometric representation and computation. Number of references: 18 Main heading: Spatial variables measurement Controlled terms: Algebra - Computation theory - Fixed platforms - Geometry - Inverse kinematics - Inverse problems - Kinematics - Mechanisms Uncontrolled terms: Conformal Geometric Algebra - Fixed coordinate systems - Forward and inverse kinematics - Forward kinematics - Geometric representation - Kinematics analysis - Spatial parallel mechanism - Theory of mechanisms Classification code: 511.2 Oil Field Equipment - 601.3 Mechanisms - 921 Mathematics - 921.1 Algebra - 931.1 Mechanics - 943.2 Mechanical Variables Measurements DOI: 10.6041/j.issn.1000-1298.2015.04.048 Database: Compendex 37.Accession number: 20151900832371 Title: Spatial distribution of soil organic matter based on topographic unit Authors: Huang, Wei1 ; Han, Zongwei1; Luo, Yun1; Zhang, Chundi1 Author affiliation: 1 College of Resource and Environment, Huazhong Agricultural University, Wuhan, China Corresponding author: Huang, Wei Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 161-167 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The spatial distribution of soil organic matter (SOM) has intimate connection with topography, but the synergy effect of topography for SOM spatial redistribution was frequently ignored in the study of SOM by traditional geostatistics. In order to investigate the influence of different topography on the spatial distribution of SOM, the method of SOM spatial interpolation based on topographic unit was proposed. Firstly, the terrain factors such as slope, aspect, topographic wetness index and topographic position index were calculated from the digital elevation data (30 m×30 m). Secondly, the topographic units were precisely divided into 13 different classical types more subtly by integrating the terrain factors, which effectively avoided the traditional terrain classification method that only based on elevation data. The regions were divided, which was based on terrain classification rules formed by the distribution of terrain factors in different landforms. Thirdly, soil samples were collected in different topographic types, and the distribution of SOM for each sample set in different topographic units was generated by ordinary Kriging. Then, the corresponding results of interpolation for each sample set were segmented based on topographic unit region, and combining the result in each region, the spatial distribution of SOM based on topographic unit was obtained. Finally, verification and comparison with the accuracy of each SOM distributions were performed, which were obtained by using topography based geostatistics and traditional global geostatistics, respectively. The results of experiment for researching the SOM distribution in Zhongxiang City showed that higher accurate and efficacious spatial layout of SOM can be acquired by geostatistics based on topographic units, especially in the gently topography region, the precision was increased by 16.39%. The SOM prediction accuracy in the rest of the terrain unit was similar to the global prediction accuracy with Pearson correlation coefficient of 0.75.Using geomorphic zoning to obtain higher accuracy for spatial distribution of SOM, and the influence of topography was considered in the study of SOM geostatistics. Number of references: 27 Main heading: Spatial distribution Controlled terms: Biogeochemistry - Biological materials - Correlation methods - Interpolation - Landforms - Organic compounds - Soil surveys - Soils - Topography Uncontrolled terms: Digital elevation data - Geo-statistics - Pearson correlation coefficients - Soil organic matters - Spatial variability - Terrain classification - Topographic unit - Topographic wetness index Classification code: 461.2 Biological Materials and Tissue Engineering - 481.1 Geology - 481.2 Geochemistry - 483.1 Soils and Soil Mechanics - 804.1 Organic Compounds - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 951 Materials Science DOI: 10.6041/j.issn.1000-1298.2015.04.024 Database: Compendex 38.Accession number: 20151900832349 Title: Optimal control algorithm and experiment of working speed of cotton-picking machine based on fuzzy PID Authors: Miao, Zhonghua1 ; Li, Chuang1; Han, Keli2; Hao, Fuping2; Han, Zengde2; Zeng, Li3 Author affiliation: 1 School of Mechatronics Engineering and Automation, Shanghai University, Shanghai, China 2 Chinese Academy of Agricultural Mechanization Sciences, Beijing, China 3 Guizhou Pingshui Machinery Co., Ltd., Anshun, China Corresponding author: Miao, Zhonghua Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 9-14 and 27 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The working efficiency of cotton-picking machine is always influenced by its working speed. To solve this problem, an algorithm for real-time adjusting the working speed was put forward based on fuzzy PID control technology. The walking speed regulation model was also established to achieve the optimal control of the working speed of cotton-picking machine. The algorithm combined the traditional PID control with fuzzy algorithm by acquiring the real-time parameters under the input load gradient congestion conditions, such as cotton production online. Both the fuzzy rules and reasoning method of PID were used to set online parameters and adjust the real-time working speed to achieve optimal control of operating speed. The field test was conducted by using 4MZ-5 five-line cotton-picking machine based on FPGA hardware. The testing result showed that the algorithm response speed was stable in 75 s. According to the cotton volume of online production, several parameters were adjusted by using fuzzy rules under the load gradient and block boundary conditions, which ensured the stability of picking up for cotton-picking machine with the best speed and improved working efficiency. It also reduced the loss in the process of picking cotton, and effectively avoided the tube plugging failure as a result of large amount of cotton. The system showed a strong flexibility and versatility and it could be used to reduce the driver's workload and improve the automation and information level for large equipment. Number of references: 15 Main heading: Cotton Controlled terms: Algorithms - Fuzzy inference - Fuzzy rules - Fuzzy sets - Load testing - Optimal control systems - Parameter estimation - Social networking (online) - Speed - Three term control systems Uncontrolled terms: Congestion conditions - Cotton picking - Cotton production - Fuzzy - pid controls - Information levels - Optimal control algorithm - Working efficiency - Working speed Classification code: 483.1 Soils and Soil Mechanics - 723 Computer Software, Data Handling and Applications - 723.4.1 Expert Systems - 731.1 Control Systems - 819.1 Natural Fibers - 921 Mathematics - 931.1 Mechanics DOI: 10.6041/j.issn.1000-1298.2015.04.002 Database: Compendex 39.Accession number: 20151900832382 Title: Wireless electronic nose based on GPRS and its application on mangos Authors: Chen, Xinwei1 ; Wang, Jun1 ; Shen, Ruiqian2 Author affiliation: 1 School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China 2 Zhejiang Golink Instrument Technology Co., Ltd., Hangzhou, China Corresponding author: Wang, Jun Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 238-245 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to meet the needs of quality detection of agricultural products during logistics, a wireless electronic nose (WEN) based on GPRS for applications in the “on-the-go” environment was designed. It consisted of 5 modules which were the sensor-array with 8 MOS sensors, signal processing module, master controlling module, GPRS module and remote monitoring system. The GPRS communication performance of the WEN was tested, it was found that when data transmission cycle exceeded 400 ms, three communication performance indexes of GPRS network which were the time-lag between sending and receiving, packet loss during the transit and transmission rate would meet the demands of detection simultaneously. An application aimed at fresh mangos was taken by using the present WEN, and the obtained profiles of mango aroma were clear and stable. Mango storage prediction models were built with stepwise regression method (SR) and LDA-SVM, respectively, and it was indicated that the SR model of the control group mango had a certain predictive effect only for the mangos stored for 4 and 6 days, the SR model of the experimental group and the LDA-SVM model either of the control group or the experimental group achieved satisfactory predictive effect as a whole. Number of references: 25 Main heading: Electronic nose Controlled terms: Agricultural products - Digital storage - Fruits - Regression analysis - Remote control - Signal processing Uncontrolled terms: Communication performance - Experimental groups - GPRS - LDA-SVM - Remote monitoring - Remote monitoring system - Stepwise regression method - Transmission rates Classification code: 716.1 Information Theory and Signal Processing - 722.1 Data Storage, Equipment and Techniques - 731.1 Control Systems - 821.4 Agricultural Products - 922.2 Mathematical Statistics DOI: 10.6041/j.issn.1000-1298.2015.04.035 Database: Compendex 40.Accession number: 20151900832378 Title: Kinetic model of coagulation process of soymilk gel based on electrical and rheological properties Authors: Xiong, Xiufang1 ; Jin, Lizhen1; Li, Xingshu1, 2 ; Guo, Kangquan1, 2 Author affiliation: 1 College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; Shaanxi, China 2 Shaanxi Engineering Research Center for Agricultural Equipment, Yangling; Shaanxi, China Corresponding author: Li, Xingshu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 211-218 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: To determine the effect of coagulation time and temperature on coagulation process of soymilk and develop a method to online evaluate soymilk gel's qualities nondestructively, electrical impedance spectroscopy (EIS) and rheological measurement (elastic modulus G' and viscous modulus G″) were employed to analyze the coagulation process. Phase angle of soymilk mixture increased drastically at low frequencies and then gradually reached around zero at high frequencies in each tested time course, and 10 kHz was chosen to evaluate soymilk coagulation process as an optimum frequency. Normalized volume resistivity at 10 kHz initially increased sharply and then gradually approached to an equilibrium state for each temperature course. The similar tendency was observed for rheological properties during soymilk coagulation process. Electrical impedance spectroscopy measurement was useful in determination of the endpoint of soymilk coagulation process. The coagulation process of soymilk was divided into two stages which were considered as two successive first-order reactions. The activation energy values calculated by volume resistivity, elastic modulus and viscous modulus were 17.82, 112.90 and 53.72 kJ/mol, respectively. The rheological properties were affected more greatly by coagulation temperature than EIS properties. Good agreements between volume resistivity and rheological properties were ascertained by the linearity of plot at all coagulation temperatures. Therefore, electrical impedance spectroscopy measurement can provide a method for determining the endpoint of soymilk coagulation process, which was also a simple, fast and realtime approach for monitoring the rheological properties of soymilk gel. Number of references: 29 Main heading: Coagulation Controlled terms: Activation energy - Elastic moduli - Electric impedance - Electric impedance measurement - Electric variables measurement - Quality control - Rheology - Spectroscopy Uncontrolled terms: Coagulation process - Coagulation temperature - Electrical impedance spectroscopy - First order reactions - Rheological measurements - Rheological property - Soy milk - Temperature course Classification code: 421 Strength of Building Materials; Mechanical Properties - 701.1 Electricity: Basic Concepts and Phenomena - 801 Chemistry - 801.4 Physical Chemistry - 802.3 Chemical Operations - 913.3 Quality Assurance and Control - 931.1 Mechanics - 942.2 Electric Variables Measurements - 951 Materials Science DOI: 10.6041/j.issn.1000-1298.2015.04.031 Database: Compendex 41.Accession number: 20151900832369 Title: Effects of rainfall and topography on soil erosion processes of black soil hillslope Authors: Li, Guifang1, 2 ; Zheng, Fenli1, 3 ; Lu, Jia3; An, Juan4 Author affiliation: 1 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling; Shaanxi, China 2 University of Chinese Academy of Science, Beijing, China 3 Institute of Soil and Water Conservation, Northwest A&F University, Yangling; Shaanxi, China 4 Institute of Water and Soil Conservation and Environment Protection, Linyi University, Linyi, China Corresponding author: Zheng, Fenli Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 147-154 and 182 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Studying hillslope soil erosion processes in the black soil region is of great importance to black soil conservation and national grain production security. A rainfall simulation study was conducted to examine the effects of rainfall intensity and topography (slope gradient and slope length) on hillslope soil erosion processes. The experimental treatments included two rainfall intensities (50 and 100 mm/h) of representative erosive rainfalls in the black soil region, two common slope gradients (5° and 10°) and two slope lengths (5 and 10 m). Each treatment had two replications. The results showed that runoff was increased by 1.4~12.4 times and 0.1~3.1 times, respectively, when rainfall intensity or slope length was increased under different treatments. Effects of slope gradient on runoff were complex, which were affected by both rainfall intensity and slope length. Rainfall intensity, slope gradient and slope length had important effects on hillslope soil loss. Soil loss was increased by 4.2 times when rainfall intensity was increased from 50 mm/h to 100 mm/h, and it was increased by 0.4 times for increasing slope gradient from 5° to 10° and 0.5 times for increasing slope length from 5 m to 10 m, which indicated that rainfall intensity had the most significant effects on hillslope soil loss. When rainfall intensity, slope gradient and slope length were increased simultaneously, soil loss was increased by 18.0 times, which suggested that the comprehensive effects of three factors were much greater than those of each single factor or the combination of two factors. Runoff had the strongest correlation with rainfall intensity, followed by coupling effects of rainfall intensity-slope length and coupling effects of rainfall intensity-slope gradient-slope length. Soil loss had the strongest correlation with coupling effects of rainfall intensity-slope gradient-slope length, followed by rainfall intensity and coupling effects of rainfall intensity-slope length. According to these observed data, the empirical equations for predicting runoff and soil loss were also established. Number of references: 38 Main heading: Rain Controlled terms: Erosion - Runoff - Soil conservation - Soils Uncontrolled terms: Hillslopes - Rainfall intensity - Slope gradients - Slope length - Soil erosion Classification code: 407 Maritime and Port Structures; Rivers and Other Waterways - 443.3 Precipitation - 444.1 Surface Water - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics DOI: 10.6041/j.issn.1000-1298.2015.04.022 Database: Compendex 42.Accession number: 20151900832363 Title: Simulation of reference evapotranspiration based on gene-expression programming method Authors: Wang, Sheng1 ; Chen, Hongsong1 ; Nie, Yunpeng1; Fu, Zhiyong1; Wang, Kelin1; Ding, Yali1 Author affiliation: 1 Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China Corresponding author: Chen, Hongsong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 106-112 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Reference evapotranspiration (ETo) is a major component of the hydrological cycle. Accurate assessment of evapotranspiration is needed for water resources management and irrigation scheduling. The performance ability of gene-expression programming (GEP) and radical basis function neural network (RBFNN) was investigated for modeling ETo in weather station of Du'an for a 5-year period (2008-2012). The data set was comprised of daily maximum temperature, minimum temperature, sunshine duration and relative humidity, which was employed for modeling ETo by using FAO-56 Penman-Monteith equation as reference. GEP results were compared with RBFNN and Hargreaves models, and their performances were evaluated through determination coefficient (R2) and root mean square error RMSE. Based on the comparisons, GEP was found to perform better than RBFNN and Hargreaves models. The GEP model which can replace Hargreaves model and the GEP model without relative humidity were established. Statistically, GEP is an effectual modeling tool for successfully computing reference evapotranspiration. Number of references: 16 Main heading: Gene expression Controlled terms: Atmospheric humidity - Data flow analysis - Ergonomics - Evapotranspiration - Genes - Mean square error - Scheduling - Water resources Uncontrolled terms: Gene expression programming - Hargreaves - Meteorological factors - Penman-Monteith models - Reference evapotranspiration Classification code: 443.1 Atmospheric Properties - 444 Water Resources - 444.1 Surface Water - 461 Bioengineering and Biology - 723.1 Computer Programming - 731.1 Control Systems - 912.2 Management DOI: 10.6041/j.issn.1000-1298.2015.04.016 Database: Compendex 43.Accession number: 20151900832353 Title: Performance optimization for intermedia stage guide vanes of multistage centrifugal pump Authors: Zhou, Shaoping1 ; Hu, Liangbo1; Zhang, Hao2 Author affiliation: 1 The Key Laboratory of Safety Science of Pressurized System, Ministry of Education, East China University of Science and Technology, Shanghai, China 2 Shanghai First Fluid Machine Co., Ltd., Shanghai, China Corresponding author: Zhou, Shaoping Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 33-39 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to investigate the flow loss in guide vanes, detached eddy simulation (DES) was used to simulate the transient flow field of a multistage centrifugal pump. The obtained numerical results were compared with experimental results, and the outcome showed that mean errors of head and efficiency were less than 4%. Simulation results analyzation showed that there were three main causes of the loss, which were flow separation in return guide vane passage, circumflux in transferable channel and collision in PS side. In order to decrease the loss, return guide vanes were designed through impeller blade design methods and transferable channels were optimized. The results showed that flow separation and collision reduced when applied impeller blade design method and circumflux reduced through TZ type transferable channel, which improved pump's efficiency by 2.4% and 1.7%, respectively. The analysis of flow fields in the coupled vanes showed that circumflux, collision and separation flow were both reduced significantly, which improved pump's efficiency by 2.9%. Number of references: 14 Main heading: Pumps Controlled terms: Centrifugal pumps - Computational fluid dynamics - Computer simulation - Design - Efficiency - Flow fields - Flow separation - Impellers Uncontrolled terms: Detached eddy simulations - Guide vane - Multi-stage centrifugal pumps - Numerical results - Performance optimizations - Separation flow - Transferable channels - Transient flow fields Classification code: 408 Structural Design - 601.2 Machine Components - 617 Turbines and Steam Turbines - 618.2 Pumps - 631 Fluid Flow - 631.1 Fluid Flow, General - 723.5 Computer Applications - 913.1 Production Engineering DOI: 10.6041/j.issn.1000-1298.2015.04.006 Database: Compendex 44.Accession number: 20151900832005 Title: Multi-objective flexible job-shop scheduling problem based on NSGA- with close relative variation Authors: Chen, Honghai1 ; Jiang, Zengqiang2; Zuo, Le2; Zhang, Yanru1 Author affiliation: 1 School of Mechanical and Automotive Engineering, Hefei University of Technology, Hefei, China 2 School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, China Corresponding author: Chen, Honghai Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 344-350 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: At present, the non-dominated sorting genetic algorithm-II (NSGA-II) is used widely in researches of flexible job-shop multi-objective rescheduling problem. Because of the excessive elite reservation, the algorithm is easily precocious, thus the performance of multi-objective optimization algorithm could be improved. By analyzing the research status and insufficiency of multi-objective flexible job-shop scheduling problem (FJSP), a multi-objective FJSP optimization model was put forward, in which the makespan, processing cost and processing quality were considered. According to the above model, a modified non-dominated sorting genetic algorithm (NSGA-II) with close relative variation was designed. In this algorithm, the chromosome mutation rate was determined after calculating the blood relationship between the two cross chromosomes. Crossover and mutation strategies of NSGA-II were optimized, and the prematurity of population was overcome. Finally, the performance of the proposed model and algorithm was evaluated through a case study, and the results demonstrated the efficiency and feasibility of the proposed model and algorithm. Number of references: 22 Main heading: Job shop scheduling Controlled terms: Algorithms - Chromosomes - Genetic algorithms - Multiobjective optimization - Optimization - Scheduling - Scheduling algorithms Uncontrolled terms: Close relative variation - Crossover and mutation - Flexible job shops - Flexible job-shop scheduling problem - Multi-objective scheduling - Non dominated sorting genetic algorithm (NSGA II) - Non dominated sorting genetic algorithm ii (NSGA II) - NSGA-II Classification code: 461.2 Biological Materials and Tissue Engineering - 723 Computer Software, Data Handling and Applications - 912.2 Management - 921 Mathematics - 921.5 Optimization Techniques DOI: 10.6041/j.issn.1000-1298.2015.04.051 Database: Compendex 45.Accession number: 20151900832384 Title: Experiment of propagation characteristics based on different frequency channels of wireless underground sensor network in soil Authors: Yu, Xiaoqing1, 2 ; Han, Wenting2 ; Wu, Pute2; Zhang, Zenglin2 Author affiliation: 1 College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; Shaanxi, China 2 Institute of Water Saving Agriculture in Arid Regions of China, Northwest A&F University, Yangling; Shaanxi, China Corresponding author: Han, Wenting Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 252-260 and 218 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: To explore wireless underground sensor network (WUSN) node deployment, signal transmission and the channel characteristics in the soil, the relationship among radio frequency signal propagation characteristics of AG-UG, UG-AG and UG-UG communication mode under wireless channel and node burial depth, horizontal inter-nodes distance and soil water content were studied with 240, 433 and 868 MHz carrier frequency for configuring wireless underground sensor networks in the soil. The experiment demonstrated that the maximum and minimum determination coefficient R2 of 24 models for goodness of fit were 0.997 and 0.910, respectively, which was the effect of node burial depth and soil water content on RSSI and BER in AG-UG and UG-AG communication. And that maximum and minimum R2 of 12 models for goodness of fit were 0.971 and 0.866, respectively, which was the effect of horizontal inter-nodes distance and soil water content on RSSI and BER in UG-UG communication. Besides, three-dimensional surface of RSSI was built with frequency of 433 MHz, which could reflect the exact wireless signal propagation characteristics in the soil environment, and the model verification experiment was conducted through SPSS software. In the AG-UG and UG-AG communication, the minimum R2 of goodness of fit was 0.954, the maximum was 0.998, and root mean square error was in the range of 0.729~3.198 dBm. In the UG-UG communication, the minimum R2 of goodness of fit was 0.854, the maximum was 0.960, and root mean square error was in the range of 3.238~6.553 dBm. Validation results showed that the model could better predict the received signal strength in different communications. The results can provide technical support for building of wireless underground sensor network system in the soil. Number of references: 19 Main heading: Wireless sensor networks Controlled terms: Experiments - Mean square error - Radio transmission - Radio waves - Sensor nodes - Soil moisture - Soils - Verification Uncontrolled terms: Determination coefficients - Propagation characteristics - Received signal strength - RF frequencies - Signal attenuation - Three-dimensional surface - Wireless signal propagation - Wireless underground sensor networks Classification code: 483.1 Soils and Soil Mechanics - 716.3 Radio Systems and Equipment - 723.1 Computer Programming - 731.1 Control Systems - 901.3 Engineering Research DOI: 10.6041/j.issn.1000-1298.2015.04.037 Database: Compendex 46.Accession number: 20151900832379 Title: Applying matrix to quantify cross-contamination of aeromonas spp. among different medium Authors: Dong, Qingli1 ; Wang, Haimei1; Malakar, Pradeep K2; Liu, Yangtai1 Author affiliation: 1 School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China 2 Gut Health and Food Safety, Institute of Food Research, Norwich, United Kingdom Corresponding author: Dong, Qingli Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 219-225 and 272 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The transfer approach and transfer probability of Aeromonas spp. under various food-handling scenarios were centralized in a two-dimensional data table by applying matrix method, which aimed at quantifying cross-contamination of Aeromonas spp. among different food-contact surfaces. Results showed that the number of Aeromonas spp. on donor and recipient surface could be calculated simultaneously, for instance, the average values of Aeromonas spp. in chilled pork before and after cross-contamination were 3.02 lg CFU/g and 1.82 lg CFU/g, respectively. Results also confirmed that proper conducts after splitting pork including cleaning contaminated boards, knives, hands and/or just changing them into clean ones before splitting Brassica chinensis could effectively reduce cross-contamination level. The study of microbial cross-contamination could be helpful for setting good hygienic practice guidelines for consumers, and it could provide a theoretical basis for assessing the potential risk of cross-contamination. Number of references: 17 Main heading: Contamination Controlled terms: Matrix algebra - Risk assessment Uncontrolled terms: Aeromonas spp - Average values - Cross contamination - Food handling - Matrix methods - Medium - Potential risks - Transfer probability Classification code: 714.2 Semiconductor Devices and Integrated Circuits - 921.1 Algebra - 922.1 Probability Theory DOI: 10.6041/j.issn.1000-1298.2015.04.032 Database: Compendex 47.Accession number: 20151900832357 Title: Runaway stabilities of pump-turbines and its correlations with S characteristic curves Authors: Yang, Jiandong1, 2 ; Zeng, Wei1, 2; Yang, Weijia3; Yao, Shangwu2; Guo, Wencheng1, 2 Author affiliation: 1 State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China 2 School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan, China 3 Department of Engineering Sciences, Uppsala University, Uppsala, Sweden Corresponding author: Yang, Jiandong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 59-64 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Pumped-storage stations can store energy and generate power according to load fluctuations, and play an important role as efficient and effective regulators in the electric grid. The safety and stability of pumped-storage station are directly related to S characteristics of pump-turbines. When pump-turbines reject their load, servomotor often fails with uncertain issues, thus leading to guide vane closing failure and the unit will go into runaway operations with high rotational speed. Pump-turbine S characteristics, however, will prevent unit parameters from converging to constants as normal Francis turbines, thus aggravating the accidents with some harmful oscillations. This phenomenon occurred in pumped-storage stations installed at the downstream surge tank was studied. The linearization method of pump-turbine characteristics was adopted to gain the transfer coefficients of pump turbines. Then, a coupling mathematic model composed of pump-turbines, conduits, surge tank and generators was established based on matrix method. It was used to deduce the stability criterion of runaway operations. It can be concluded that the runaway oscillation of pump-turbines was caused by a couple of factors, in which the slopes of characteristic curves at the runaway point were dominated. Model tests were conducted on a model pumped-storage station in the laboratory which is composed of nine sub-systems. The model data of runaway conditions of two different pump-turbines were gained, and the conclusions of the theoretical analyses were validated. Number of references: 16 Main heading: Hydraulic turbines Controlled terms: Digital storage - Pumped storage power plants - Pumps - Stability criteria - Surge tanks - Tanks (containers) Uncontrolled terms: Characteristic curve - High rotational speed - Linearization methods - Pump-turbines - Pumped storage station - S characteristics - Safety and stabilities - Transfer coefficient Classification code: 402.1 Industrial and Agricultural Buildings - 617.1 Hydraulic Turbines - 618.2 Pumps - 619.2 Tanks - 722.1 Data Storage, Equipment and Techniques - 961 Systems Science DOI: 10.6041/j.issn.1000-1298.2015.04.010 Database: Compendex 48.Accession number: 20151900832373 Title: Fractal features of soil particle size distributions and its effect on soil erosion of Loess Plateau Authors: Ru, Hao1 ; Zhang, Jianjun1 ; Li, Yuting1; Yang, Zongru2; Feng, Huancheng2 Author affiliation: 1 School of Soil and Water Conservation, Beijing Forestry University, Beijing, China 2 Forestry Bureau of Ji County, Linfen, China Corresponding author: Zhang, Jianjun Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 176-182 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Fractal theory was used as one of the methods to quantitatively analyze soil particle size distribution (PSD) because it can better describe soil physical properties. The single- and multi-fractal were used to analyze the features of the soil PSD, the effects of different land use types on fractal parameters and the relationship between fractal parameters and soil PSD. Results showed that soil PSD was diversity in different regions of the Loess Plateau. Soil particle size, which was measured by laser method, was mainly distributed in two power-law domains, named Dsilt and Dsand. It was needed to redefine the domain boundary of Dclay, Dsilt and Dsand. Soil particle size was distributed in range of 20~100 μm which was narrow and presented obvious heterogeneity, thus it was necessary to use multi-fractal method to describe soil particle distribution characteristics. The correlation analysis indicated that Dsilt showed prominent positive correlation with content of clay and silt (P<0.01), Dsand showed negative correlation with sand content but not prominent. Consequently, Dsilt can be used to predict the change of soil texture and soil erosion degree of different land use types. There was an extremely remarkable effect of land use types on clay, silt, sand content, Dsilt, D0, D1 and D1/D0 value (P<0.01), and remarkable effect on Dsand (P<0.05), which indicated that multi-fractal parameters can be the indexes to reflect effects on soil properties. Number of references: 24 Main heading: Particle size Controlled terms: Erosion - Fractal dimension - Fractals - Land use - Landforms - Light transmission - Particle size analysis - Sand - Sediments - Silt - Size distribution - Soils Uncontrolled terms: Correlation analysis - Different land use types - Land use type - Loess Plateau - Positive correlations - Soil erosion - Soil particle size - Soil physical property Classification code: 403 Urban and Regional Planning and Development - 423 Non Mechanical Properties and Tests of Building Materials - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 741.1 Light/Optics - 921 Mathematics - 943.2 Mechanical Variables Measurements - 951 Materials Science DOI: 10.6041/j.issn.1000-1298.2015.04.026 Database: Compendex 49.Accession number: 20151900832375 Title: Performance of downdraft gasifier for hydrogen-rich gas by high temperature steam gasification of biomass Authors: Niu, Yonghong1 ; Ma, Lijun1; Chen, Yisheng2; Pang, Yunji3; Chen, Junjun1 Author affiliation: 1 School of Energy and Environment, Inner Mongolia University of Science and Technology, Baotou, China 2 Analytical Center, Inner Mongolia University of Science and Technology, Baotou, China 3 School of Energy and Power Engineering, Dalian University of Technology, Dalian, China Corresponding author: Niu, Yonghong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 189-193 and 232 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In recent years, high temperature steam gasification (HTSG) is a new gasification technology which utilizes super-heated, high temperature steam as gasifying agent as well as partial heat carrier. A HTSG experimental platform for generating hydrogen-rich gas from biomass was proposed. The experimental platform included a high temperature steam generating system, a downdraft gasifier, a gas purification system, a sample gas collection system and an automatic control system. The gasification performance of the downdraft gasifier was evaluated by using pine wood shavings which considered the effects of reaction temperature. The steam temperature was controlled from 600 to 1 000 during experiment. The results showed that combustible gas composition over volume fraction of 77% was obtained in these experiments. The volume fraction of H2 increased and CO and CH4 decreased as the reaction temperature increased. When steam temperature was (948±4), the volume fraction of H2 reached (51.83±0.12)%, the lower heating value of produced gas was 9.81 MJ/m3, composition ratio of H2/CO reached 2.17 and the gas produced by high temperature steam gasification can be stable to burn, thus the gasification performance was regarded as relatively perfect. High temperature steam gasification is an effective way by using biomass such as pine wood shavings for making hydrogen rich gas, and it has the huge development potential and application space. The results could provide guidance for gasifier and engineering design of the biomass gasification. Number of references: 23 Main heading: Gasification Controlled terms: Air purification - Automation - Biomass - Calorific value - Gases - Hydrogen - Steam - Volume fraction Uncontrolled terms: Biomass Gasification - Development potential - Downdraft gasifier - Experimental platform - Gas collection systems - Gasification technologies - High temperature steam gasifications - Hydrogen-rich gas Classification code: 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 525.1 Energy Resources and Renewable Energy Issues - 641.1 Thermodynamics - 643 Space Heating, Ventilation and Air Conditioning - 672 Naval Vessels - 731 Automatic Control Principles and Applications - 732 Control Devices - 802.3 Chemical Operations - 804 Chemical Products Generally - 931.2 Physical Properties of Gases, Liquids and Solids DOI: 10.6041/j.issn.1000-1298.2015.04.028 Database: Compendex 50.Accession number: 20151900832351 Title: Effect of blade numbers on cavitating flow of centrifugal pump under low flow rates Authors: Fu, Yanxia1 ; Yuan, Shouqi1 ; Yuan, Jianping1; Zhou, Banglun1; Wang, Peng1 Author affiliation: 1 Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China Corresponding author: Yuan, Shouqi Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 21-27 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to investigate the cavitation characteristics of centrifugal pumps under low flow rates, the cavitating flows in the centrifugal pump typed IS50-65-160 with three different blade-number impellers were numerically simulated based on the k-Ε turbulent model combined with Rayleigh-Plesset cavitation model by using the software ANSYS CFX 14.5. Meanwhile, grid independence check was carried out to verify the accuracy of calculation. The effect of blade numbers on the cavitation characteristics in the pump was firstly analyzed from the points of suction performances, torque as well as axial forces acted on impellers. The results showed that as the blade number increased from 4 to 8, the pump head increased while the variable regulation of its efficiency was quite complicated. Both the head-drop and torque-drop curves of impellers with three different blade numbers had the same shape of creeping dropping, with the corresponding break-down points occurring asynchronously. The axial forces acted on impellers almost kept constant as the amount of head dropping was 3% or higher. The vapor volume in one blade was larger than others, and finally a significantly asymmetric distribution occurred on all blades. It was firstly obtained that the creeping-drop characteristics of both pump head and torque acted on the impellers were possibly related to onset of asymmetric blade cavitation phenomenon. Moreover, this study to some extent can also provide some reference for the design of centrifugal pump in the industry in case of avoiding serious cavitation occuring at low flow rates. Number of references: 19 Main heading: Cavitation Controlled terms: Axial flow - Centrifugal pumps - Computer simulation - Drops - Flow rate - Impellers - Pumps - Well pumps Uncontrolled terms: Asymmetric distribution - Blade numbers - Cavitation characteristics - Cavitation performance - Cavitation phenomenon - Drop characteristics - Suction performance - Vapor volume fraction Classification code: 443.1 Atmospheric Properties - 601.2 Machine Components - 618.2 Pumps - 631 Fluid Flow - 723.5 Computer Applications DOI: 10.6041/j.issn.1000-1298.2015.04.004 Database: Compendex 51.Accession number: 20151900832385 Title: Dielectric soil moisture sensing technique based on horizontal scale expansion Authors: Zhou, Haiyang1 ; Sun, Yurui1 ; Schulze Lammers, P.2; Shan, Guilin1; Cheng, Qiang1; Wen, Boying1 Author affiliation: 1 Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, China Agricultural University, Beijing, China 2 Institute of Agricultural Engineering, University of Bonn, Bonn, Germany Corresponding author: Sun, Yurui Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 261-265 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: To date diverse soil moisture sensors have been commercially available but all of these are at point-scales of centimeters-to-decimeters with limited volume of sensitivity (VOS). In many cases, the spatial variability of soil moisture distribution can be considerably larger than the VOS. A novel motorized dielectric PVC-tube sensor prototype was presented for horizontally scanning soil moisture content (maximum scanning length 380 cm). The sensing probe was cylindrical and thus can be mobilized through the PVC tube which was horizontally embedded at a certain depth of soil layer. In order to prove its technical feasibility, two case applications associated with drip emitter tests were presented as well. The experimental results demonstrated that the applications were potential to support the model validation for simulating water migration, monitor soil water variation in root-zone accompanying plant growth, provide one-dimension data for precision irrigation and evaluate the effectiveness of irrigation equipment. Number of references: 26 Main heading: Soil moisture Controlled terms: Irrigation - Moisture - Moisture control - Moisture meters - Soils - Tubes (components) Uncontrolled terms: Irrigation equipment - Linear scan - Precision irrigation - Scanning lengths - Soil moisture distribution - Soil moisture sensing - Soil moisture sensors - Spatial variability Classification code: 483.1 Soils and Soil Mechanics - 616.1 Heat Exchange Equipment and Components - 801.4 Physical Chemistry - 821.3 Agricultural Methods - 944.1 Moisture Measuring Instruments - 944.2 Moisture Measurements DOI: 10.6041/j.issn.1000-1298.2015.04.038 Database: Compendex 52.Accession number: 20151900832366 Title: Impact of super absorbent polymers dosage on carbon footprint of farmland ecological system Authors: Yang, Yonghui1 ; Wu, Jicheng1, 2; Zhao, Shiwei3 ; Pan, Xiaoying1, 2; He, Fang1, 2 Author affiliation: 1 Institute of Plant Nutrition & Resource Environment, Henan Academy of Agricultural Sciences, Zhengzhou, China 2 Yuanyang Experimental Station of Crop Water Use, Ministry of Agriculture, Yuanyang, China 3 Institute of Soil and Water Conservation, Northwest A&F University, Yangling; Shaanxi, China Corresponding author: Zhao, Shiwei Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 126-131 and 125 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to investigate the effect of super absorbent polymers (SAP) dosage on the carbon footprint of farmland ecological system, a field experiment was conducted to study carbon absorption, carbon emission, carbon cost, carbon efficiency and net carbon sink. The results indicated that although the application of SAP and various agricultural inputs increased farmland carbon footprint, they promoted the growth of crop and improved quality of crop dry biomass. Thus SAP and various agricultural inputs significantly improved the carbon absorption, reduced carbon cost and improved the efficiency of carbon and net carbon sink. Carbon cost of the treatment with 60 kg/hm2 of SAP was the minimum, which was reduced by 25.6% compared with the control, while its carbon efficiency and net carbon sink were the maximum, which were increased by 35.3% and 30.6% than that of the control, respectively. Meanwhile, SAP could improve water use efficiency of winter wheat, the treatment with 60 kg/hm2 of SAP was the best. The correlation analysis among different factors showed that positive correlations were found between water use efficiency, carbon sequestration, carbon efficiency and carbon net sink, while negative correlation was found between water use efficiency and carbon cost. Number of references: 23 Main heading: Carbon footprint Controlled terms: Absorption - Agriculture - Carbon - Cost benefit analysis - Cost reduction - Costs - Crops - Ecology - Efficiency - Environmental impact - Farms - Polymers Uncontrolled terms: Carbon sequestration - Carbon sink - Correlation analysis - Ecological systems - Negative correlation - Positive correlations - Superabsorbent polymer - Water use efficiency Classification code: 454 Environmental Engineering - 804 Chemical Products Generally - 815.1 Polymeric Materials - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 911 Cost and Value Engineering; Industrial Economics - 911.2 Industrial Economics - 913.1 Production Engineering - 931.2 Physical Properties of Gases, Liquids and Solids DOI: 10.6041/j.issn.1000-1298.2015.04.019 Database: Compendex 53.Accession number: 20151900832361 Title: Root distribution and soil water dynamics of jujube plantations in loess hilly regions Authors: Wei, Xindong1, 2 ; Wang, Xing1; Wang, Youke1, 2 ; Zhou, Yuhong1; Miao, Ling3 Author affiliation: 1 College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; Shaanxi, China 2 College of Earth Science and Resources, Chang'an University, Xi'an, China 3 Institute of Soil and Water Conservation, Northwest A&F University, Yangling; Shaanxi, China Corresponding author: Wang, Youke Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 88-97 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: The spatial correlation between soil water content and root distribution in non-irrigation dense-dwarf jujube plantations was analyzed in semiarid hilly loess region of China. The soil coring method was used to sample roots at different depths within the 0~1 000 cm soil profile under different-aged jujube plants (1, 3, 5 and 12 a). The results showed that the increment of average annual root depth decreased with the increase of jujube stand age. The maximum root depth of 12-year-old jujube was 520 cm and the minimum root depth was 100 cm from the tree base, which was half-way between two trees planted 2 m apart. The difference between maximum and minimum root depths of 12-year-old jujube trees was 180 cm. Lateral roots started developing intersection networks after three years of planting. Soil water fluctuation was not induced by vertical root systems of dense-dwarf jujube plants. Root depth, dry soil layer depth and annual soil water variance within top 0~200 cm soil layer increased with increase of jujube stand age. However, root-zone soil water content decreased with increase of stand age, while dry soil layer depth was slightly larger than root depth. The results can provide vital technical support for jujube cultivation especially under semiarid conditions. Number of references: 36 Main heading: Soils Controlled terms: Cultivation - Forestry - Sediments - Soil moisture Uncontrolled terms: Intersection networks - Jujube forest - Loess hilly regions - Root system - Semi-arid conditions - Soil water content - Soil water dynamics - Spatial correlations Classification code: 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 821.0 Woodlands and Forestry - 821.3 Agricultural Methods DOI: 10.6041/j.issn.1000-1298.2015.04.014 Database: Compendex 54.Accession number: 20151900832387 Title: Predicting light use efficiency with chlorophyll fluorescence spectra based on SVM Authors: Ren, Shun1 ; Yu, Haiye1 ; Zhou, Li'na2 Author affiliation: 1 School of Biological and Agricultural Engineering, Jilin University, Changchun, China 2 College of Engineering and Technology, Jilin Agricultural University, Changchun, China Corresponding author: Yu, Haiye Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 273-276 and 251 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: Light use efficiency is an important parameter of plant productivity model. It is an evaluation index for plant to turn the solar energy into dry matter efficiency. Taking cucumbers as the study objects, a method for light use efficiency prediction was proposed with the help of analysis technique of laser-induced chlorophyll fluorescence spectra based on the theory of support vector machine (SVM). Chlorophyll fluorescence spectra, net photosynthetic rate and photosynthetic active radiation of cucumber leaves were synchronously acquired, and the 500~800 nm band of chlorophyll fluorescence spectrum was selected as study objects. Firstly, the original spectra was pretreated by SG-FDT method. Secondly, the characteristic values of pretreated spectra were extracted by using principal component analysis (PCA) method, the first ten principal components whose cumulative contribution rate was 93.49% were selected instead of the original spectral information in the study. Finally, the prediction model of light use efficiency was established through the SVM with the radial basis function. The penalty parameter C and kernel function parameter g were ultimately determined as C=0.031 25, g=1 by carrying out a large number of tests, and then 60 training samples were combined to train the model. Ten testing samples were used to test the established model, and the results showed that the average error of the testing samples was 8.94%, which indicated a good predictive power. Number of references: 20 Main heading: Principal component analysis Controlled terms: Chlorophyll - Fluorescence - Forecasting - Laser theory - Plants (botany) - Radial basis function networks - Solar energy - Support vector machines Uncontrolled terms: Chlorophyll fluorescence - Kernel function parameters - Laser-induced chlorophyll fluorescences - Light use efficiency - Net photosynthetic rate - Photosynthetic active radiations - Radial basis functions - Spectral information Classification code: 461.9 Biology - 615.2 Solar Power - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 741.1 Light/Optics - 744.1 Lasers, General - 804.1 Organic Compounds - 922.2 Mathematical Statistics DOI: 10.6041/j.issn.1000-1298.2015.04.040 Database: Compendex 55.Accession number: 20151900832393 Title: Multi-neighborhood structure based multi-objective genetic algorithm Authors: Zhu, Dalin1 ; Zhan, Teng1, 2; Zhang, Yi1; Zheng, Xiaodong1; Zhang, Denghuang1; Yu, Zhuma1 Author affiliation: 1 College of Mechanical & Power Engineering, China Three Gorges University, Yichang, China 2 Zhuzhou Lince Group Co., Ltd., Zhuzhou, China Corresponding author: Zhu, Dalin Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title: Nongye Jixie Xuebao Volume: 46 Issue: 4 Issue date: April 25, 2015 Publication year: 2015 Pages: 309-315 and 324 Language: Chinese ISSN: 10001298 CODEN: NUYCA3 Document type: Journal article (JA) Publisher: Chinese Society of Agricultural Machinery Abstract: In order to solve the problem of multi-objective size optimization of truss structures with stress constraints, a multi-objective optimization algorithm with multi-neighborhood was proposed. Based on the Euclidean distance between individuals, the population was divided into multi-neighborhood to form several niche populations. A number of individuals were assigned to each cell as neighborhood by the proposed algorithm. The individuals were only allowed interacting with each other within its neighborhood and generating offspring. The influence of different sizes of neighbors on the performance was analyzed through simulation experiments. The test results on 18 benchmarks revealed that the proposed algorithm outperformed some state-of-the-art algorithm in terms of covered area and diversity, which showed good uniformity and diversity. The obtained Pareto front showed good uniformity and diversity when solving the classic multi-objective optimization problem of 25-bar truss structure. The algorithm showed good performance in program design, solution space and generality and so on, which was very simple, practical and suitable for engineering practice. Number of references: 21 Main heading: Multiobjective optimization Controlled terms: Algorithms - Buckling - Genetic algorithms - Optimization - Shape optimization - Structural optimization - Trusses Uncontrolled terms: Engineering practices - Euclidean distance - Multi-objective genetic algorithm - Multi-objective optimization problem - Neighbor size - Neighborhood structure - State-of-the-art algorithms - Truss structure Classification code: 408.2 Structural Members and Shapes - 723 Computer Software, Data Handling and Applications - 921 Mathematics - 921.5 Optimization Techniques DOI: 10.6041/j.issn.1000-1298.2015.04.046 Database: Compendex
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