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2014年第45卷第9期共收录55篇 1. Accession number:201442113333 Title:Identification method of electronic nose based on KFDA for different vinegar samples Authors:Yin, Yong1 ; Xue, Junli1 ; Yu, Huichun1 ; Chen, Hongyou1 ; Meng, Miaojuan1 Author affiliation:1 School of Food & Bioengineering, Henan University of Science and Technology, Luoyang, China Corresponding author:Yin, Yong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:236-240 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:In order to enhance the correct rate of identification result of six kinds of vinegars, a kernel Fisher discriminant analysis (KFDA) method is introduced. And a measuring method of matrix similarity based on distance discrimination was presented to define the radial basis function (RBF) characteristic parameter, where RBF was selected as the kernel function. The measuring method is that, firstly, an ideal Gram matrix is defined, and the actual kernel Gram matrix is calculated by RBF; secondly, Euclidean distance can be employed to measure the degree of approximation between the actual kernel Gram matrix and the ideal Gram matrix; finally, the optimal kernel parameter can be obtained by extremal solution of the distance. When two kinds of feature vectors, whose were integral value and average value in relative steady-state, were extracted from the E-nose signals of vinegar samples, the corresponding characteristic parameters were 5.770 0 (integral value) and 5.387 8 (average value in relative steady-state). Comparing and analyzing the results of Fisher discriminant analysis (FDA) and KFDA, their identification correct rates were respectively from 93.3% and 90.6% (FDA) up to 98.3% and 98.3% (KFDA). This indicates that the suitable KFDA method can effectively improve the identification results of the six kinds of vinegar samples. Number of references:16 Main heading:Identification (control systems) Controlled terms:Acetic acid - Discriminant analysis - Face recognition - Fisher information matrix - Learning algorithms - Radial basis function networks Uncontrolled terms:Degree of approximation - Electronic NOSE - FDA - Fisher discriminant analysis - Kernel fisher discriminant analysis - KFDA - Radial Basis Function(RBF) - Vinegar Classification code:716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 731.1 Control Systems - 804.1 Organic Compounds - 922 Statistical Methods DOI:10.6041/j.issn.1000-1298.2014.09.038 Database:Compendex 2. Accession number:201442113328 Title:Growth of pseudomonas aeruginosa single cells and cell colonies Authors:Dong, Qingli1 ; Wang, Xin1 ; Ding, Tian2 ; Liu, Qing1 ; Liu, Yangtai1 Author affiliation:1 School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China 2 School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China Corresponding author:Dong, Qingli Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:204-209 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A flow chamber image system was used to study the single cell growth of Pseudomonas Aeruginosa. A stochastic modeling process was applied to connect the growth of P. Aeruginosa single cells and cell colonies, and made it possible to simulate the population growth of P. Aeruginosa. Experimental bacteria growth viable counts using different initial inoculum sizes were detected to validate the simulation process. Meanwhile, many simulations were carried out to verify the effect of inoculum size on the lag time of P. Aeruginosa. The results indicate that the agreement between simulations and viable counts is good at both 25 and 35 and the simulation process can be one of methods for predicting the population growth of P. Aeruginosa. Through many simulations, it demonstrates that the lag time decreased from 12.52 h to 6.33 h at 25 and 8.61 h to 4.01 h at 35 as the initial inoculum size increased from 0 CFU/mL to 100 CFU/mL. The uncertainty and variability in bacteria cell growth are shown clearly in the simulation process. Also this method can be used as a reference to predict bacterial population growth and to study the lag behavior of microorganism. Number of references:21 Main heading:Bacteria Controlled terms:Cell growth - Cells - Cytology - Growth kinetics - Population statistics - Stochastic systems Uncontrolled terms:Image systems - Lag-time - Predictive micro-biology - Pseudomonas aeruginosa - Single cells Classification code:461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 922.2 Mathematical Statistics - 961 Systems Science DOI:10.6041/j.issn.1000-1298.2014.09.033 Database:Compendex 3. Accession number:201442113315 Title:Experiment research of cavitating flow over mini cascade Authors:Zhang, Yao1 ; Zhou, Zhijie1 ; Luo, Xianwu2 ; Xu, Hongyuan2 Author affiliation:1 China Ship Development and Design Center, Wuhan, China 2 Key Laboratory for CO2 Resource Utilization and Emission Reduction of Beijing, Tsinghua University, Beijing, China Corresponding author:Zhang, Yao Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:119-124 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The mini pump having the characteristic dimension of 1~50 mm, has been becoming promising fluid machinery with the growing application in aerospace, new energy and agricultural machinery area for its small size. The cavitating flows over cascade having the chord length of 14mm have been investigated in a cavitation tunnel at different cavitation numbers to study the mechanism and scale effects of cavitation at miniature dimension. Based on the analysis of experimental results, it is shown that the cavitation in miniature flow passage can experience several states such as cavitation inception, sheet cavitation, cloud cavitation and super cavitation with the decrease of cavitation number. For the mini cascade cavitating flow, the cavity characteristics are different from that of single mini hydrofoil because of the interaction among the flows in neighboring flow channels. The mass transfer between liquid and gas phase caused by cavitation for mini cascade is less intense than that for single mini hydrofoil. Thus, there is no large scale cavity shedding in cloud cavitation period in mini cascade. Also, the cavity shape of mini cascade appears thinner and longer at different cavitation states and cavitation development is also hysteresis. Number of references:14 Main heading:Cavitation Controlled terms:Agricultural machinery - Hydrofoils Uncontrolled terms:Cavitation inception - Cavitation tunnels - Cloud cavitations - Experiment research - Flow passage - Fluid machineries - Sheet cavitation - Super cavitation Classification code:631.1.1 Liquid Dynamics - 821.1 Agricultural Machinery and Equipment DOI:10.6041/j.issn.1000-1298.2014.09.020 Database:Compendex 4. Accession number:201442113307 Title:Parallel and fast reconstruction algorithm for compressed sensing apple image Authors:Dai, Yuan1, 2 ; He, Dongjian1 ; Yang, Long2 Author affiliation:1 College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; Shaanxi, China 2 College of Information Engineering, Northwest A&F University, Yangling; Shaanxi, China Corresponding author:He, Dongjian Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:72-78 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:With the emerging of compressed sensing (CS), it is possible to overcome the storage and transmission difficulty of the mass data sampled by traditional methods. It also provides a new way for machine vision applied to apple image sampling. However, the major shortcoming of the reconstruction algorithms for CS signals is the expensive computing time, which limits its applications to the occasions requiring fast processing. Aiming at this problem, two dimensional orthogonal matching pursuit algorithm with parallel computing is proposed for apple image reconstruction. The parallelism of the algorithm is analyzed and the parallel algorithm using CUDA technology on GPU is designed in order to achieve a fast reconstruction algorithm. Experimental results show that the parallel algorithm improves the recovery efficiency by 16 to 35 times and the apple image can be recovered in several seconds. This method provides a new technical support to remote monitoring in real time for apple garden. It can be used in the fast apple quality detection based on image as well. Number of references:18 Main heading:Image matching Controlled terms:Algorithms - Compressed sensing - Computer vision - Digital storage - Fruits - Image processing - Image reconstruction - Parallel algorithms - Parallel architectures - Parallel processing systems - Signal reconstruction Uncontrolled terms:Apple - Compressive sensing - CUDA technologies - Fast reconstruction algorithms - Orthogonal matching pursuit - Quality detection - Reconstruction algorithms - Recovery efficiency Classification code:716.1 Information Theory and Signal Processing - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 741 Light, Optics and Optical Devices - 741.2 Vision - 821.4 Agricultural Products - 921 Mathematics DOI:10.6041/j.issn.1000-1298.2014.09.012 Database:Compendex 5. Accession number:201442113298 Title:Electronic control unit of electronically controlled air suspension systems based on code generation Authors:Yan, Tianyi1 ; Liu, Xinqiang1 ; Zhang, Luzou1 ; Wang, Yulin1 ; Choi, S.B.2 Author affiliation:1 College of Mechanical & Electrical Engineering, Qingdao University, Qingdao, China 2 Department of Mechanical Engineering, Inha University, Incheon, Korea, Republic of Corresponding author:Yan, Tianyi Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:14-19 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:To improve a SUV's ride quality and mobility, the SUV was modified using air suspension systems. An electronic control unit based on Freescale XDP512 microcontroller was designed including a minimum system, a speed signal conditioning module, an air pump control module, a combined valves control module, a body height measuring module and a CAN module, a body acceleration measuring module. The ANSI C code of the control strategy of the ECAS system was generated using Real-Time Workshop (RTW) code generation techniques, and then series of experiments of the car body coupling with speed, cornering, accelerating, decelerating, ride quality were conducted. The results of the experiments showed that the newly designed ECU could effectively finish the following functions: vehicle speed signal conditioning, the coupling of suspension height and vehicle speed, the control of an electrical air pump and a combination valves, etc. Number of references:14 Main heading:Quality control Controlled terms:Air mobility - Automatic programming - Automobile bodies - Automobile suspensions - C (programming language) - Codes (symbols) - Control systems - Industrial electronics - Network components - Servomechanisms - Strain measurement - Suspensions (components) - Valves (mechanical) - Vehicles Uncontrolled terms:Air suspension - Air suspension systems - Automatic code generations - Body acceleration - Control strategies - Electronic control units - Real time workshop - Suspension height Classification code:431.1 Air Transportation, General - 432 Highway Transportation - 601.2 Machine Components - 632.1 Hydraulics - 663.2 Heavy Duty Motor Vehicle Components - 703.1 Electric Networks - 705 Electric Generators and Motors - 714 Electronic Components and Tubes - 715 Electronic Equipment, General Purpose and Industrial - 716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 913.3 Quality Assurance and Control - 943.2 Mechanical Variables Measurements DOI:10.6041/j.issn.1000-1298.2014.09.003 Database:Compendex 6. Accession number:201442113319 Title:Indoor automatic measurement system for rainfall infiltration based on PLC Authors:L, Huafang1 ; Yang, Hanbo1 ; Cong, Zhentao1 ; Lei, Huimin1 Author affiliation:1 State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing, China Corresponding author:L, Huafang Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:144-149 and 160 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Based on the measuring method of manual rainfall infiltration with the Mariotte bottle, an indoor automatic measurement system for rainfall infiltration with PLC (programmable logical controller) and touch panel was designed. This system could automatically water to the Mariotte bottle, adjust rainfall intensity, display and record experiment data in real time, and also provide the function of data query. The PLC collects the analog signal and transforms it into a digital signal, which is used to control the water input of the Mariotte bottle to regulate water level through switching the two electromagnetic valves. In addition, the PLC controls regulating valve opening to adjust the rainfall intensity. Furthermore, this system can be operated easily, rationally reflect the infiltration process, and give a high precision measurement. Number of references:29 Main heading:Infiltration Controlled terms:Bottles - Programmable logic controllers - Rain - Search engines - Water levels Uncontrolled terms:Automatic determination - Automatic measurement system - Electromagnetic valves - High-precision measurement - Infiltration process - Programmable logical controller - Rainfall infiltration - Rainfall intensity Classification code:443.3 Precipitation - 452.1 Sewage - 614.2 Steam Power Plant Equipment and Operation - 694.2 Packaging Materials - 723 Computer Software, Data Handling and Applications - 732.1 Control Equipment DOI:10.6041/j.issn.1000-1298.2014.09.024 Database:Compendex 7. Accession number:201442113309 Title:Inverse design and hydraulic optimization of mixed-flow pump impeller Authors:Xiao, Ruofu1 ; Tao, Ran1 ; Wang, Weiwei1 ; Yang, Wei1 Author affiliation:1 College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China Corresponding author:Xiao, Ruofu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:84-88 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A reliable and convenient optimism method was introduced. Based on a mixed-flow pump designed by 3-dimensional inverse design method and combined with CFD, an optimization design was conducted with the blade-loading as the design variable and the hydraulic efficiency as the optimization objective. With CFD simulation results, the relationship between the hydraulic efficiency and the blade-loading was established by orthogonal test and response surface method. The optimization results show that the blade loading on hub near leading edge has the most significant influence on the hydraulic efficiency. Compared with the pump model with the reference impeller, the hydraulic efficiency of the pump model with optimized impeller increases by 3.2% while the head keeps constant. Number of references:13 Main heading:Computational fluid dynamics Controlled terms:Design - Efficiency - Impellers - Pumps - Surface properties Uncontrolled terms:Hydraulic efficiency - Hydraulic optimizations - Inverse design methods - Inverse designs - Mixed flow pump - Mixed-flow pump impellers - Orthogonal test - Response surface method Classification code:408 Structural Design - 601.2 Machine Components - 618.2 Pumps - 913.1 Production Engineering - 921.6 Numerical Methods - 951 Materials Science DOI:10.6041/j.issn.1000-1298.2014.09.014 Database:Compendex 8. Accession number:201442113306 Title:Geometric parameters recognition of fresh tea leaf based on constrained delaunay triangulation Authors:He, Xuejun1 ; Wang, Jin1 ; Lu, Guodong1 ; Tang, Xiaolin2 Author affiliation:1 State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou, China 2 Hangzhou Tea Research Institute, China CO-OP, Hangzhou, China Corresponding author:Wang, Jin Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:66-71 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:To automatically recognize the geometric parameters of fresh tea leaves with different orientations, constrained Delaunay triangulation was introduced to triangulate the area of fresh tea leaf after operations, which made the contour points distribute evenly and sparsely. Then, with the character of end triangle, adjacent triangle and connect triangle, median axis of tea leaves and tea stalks were calculated, thus the orientation of a fresh tea leaf was determined and the tea leaf was labeled. At the same time, the length, width, and area of each tea leaf was calculated, as well as distance between petioles. Based on above results, a geometric feature index concerning the oldness of fresh bulk tea was proposed, and a possible method to finely divide the grade of fresh tea was also discussed. Totally 150 images with 174 pieces of fresh tea leaves were used to validate the algorithm, and a recognition rate of 94.2% was obtained, and the average time to treat a single fresh tea leaf was 74.7 ms. Number of references:12 Main heading:Geometry Controlled terms:Surveying - Triangulation Uncontrolled terms:Constrained Delaunay triangulation - Contour points - Delau-nay triangulations - Fresh tea leaf - Geometric feature - Geometric parameter - Recognition - Tea leaves Classification code:405.3 Surveying - 921 Mathematics DOI:10.6041/j.issn.1000-1298.2014.09.011 Database:Compendex 9. Accession number:201442113330 Title:Comparison of transfer and correctional methods for pork pH value detection of different varieties by hyperspectral imaging technique Authors:Li, Xiaoyu1 ; Zhong, Xiongbin1 ; Liu, Shanmei2 ; Huang, Tao1 ; Wu, Zhenzhong1 Author affiliation:1 College of Engineering, Huazhong Agricultural University, Wuhan, China 2 College of Sciences, Huazhong Agricultural University, Wuhan, China Corresponding author:Li, Xiaoyu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:216-222 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The calibration model of the pork quality based on hyperspectral data was easily affected by pork varieties and had poor applicability. So different algorithms were compared and a calibration transfer algorithm based on spectral value correction was proposed to improve the model applicability between different varieties. The PLS model for Shanhei pig was established, then was used to predict Linghao pig samples. Prediction accuracy was very poor with only Rp of 0.415, and RMSEP of 0.1804. To improve model applicability, S/B algorithm, model updating and transfer algorithm based on spectral value correction were respectively adopted and compared. For S/B algorithm, Rp of the model prediction for Linghao pig samples was still 0.415, and RMSEP decreased from 0.1804 to 0.1343, only down by 25.54%. For the model updating method, when 14 Linahao pig samples were added to the calibration dataset, the model prediction performance for Linghao pig samples achieved optimal. Rp increased to 0.797, improved by 92.05%, and RMSEP reduced to 0.1121, dropped by 37.86%. For transfer algorithm based on spectral value correction which combined spectral value-physical value coexist distance with DS algorithm, Rp of the model prediction for Linghao pig samples increased to 0.837, rose by 101.69%, and RMSEP reduced to 0.0856, fell by 52.55%. The results showed that the transfer algorithm based on spectral value correction could eliminate the difference of spectral value of different varieties efficiently and improve the model applicability. It gave the best transfer and correction result than the two other algorithms. Number of references:19 Main heading:Algorithms Controlled terms:Forecasting - Imaging techniques - Mammals - Meats - pH - Spectroscopy Uncontrolled terms:Calibration transfer - Hyperspectral Data - Hyperspectral detections - Hyperspectral imaging techniques - Model transfer - pH value - Prediction accuracy - Spectral correction Classification code:723 Computer Software, Data Handling and Applications - 741 Light, Optics and Optical Devices - 746 Imaging Techniques - 801 Chemistry - 801.1 Chemistry, General - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 921 Mathematics DOI:10.6041/j.issn.1000-1298.2014.09.035 Database:Compendex 10. Accession number:201442113343 Title:Three dimensional steady simulation of microclimate pattern inside single plastic greenhouse using computational fluid dynamics Authors:Hao, Feilin1 ; Shen, Mingwei2 ; He, Yong2 ; Feng, Lei2 Author affiliation:1 College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou, China 2 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China Corresponding author:Shen, Mingwei Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:297-304 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:To explore the microclimate factors, such as air-flow, temperature, humidity and CO2 concentration inside a single-span plastic greenhouse, an environmental model was established including components of greenhouse such as inner and outer space, plant and soil layer, etc. The air was assumed to be composed of dry gas, water vapor and CO2. Based on the solar radiation, mass-thermal exchange of plant-environment, transmitting process of energy and momentum of various parts, three dimensional simulation was executed to predict the pattern of temperature, humidity and CO2 concentration. The Monte Carlo method was adopted in the model of thermal-radiation transport process. Plant was simplified as continuous solid medium, and shear stress transport (SST) model was used in air turbulence analysis. The results showed that the ventilation pattern had an obvious effect on distribution of temperature, humidity and CO2 concentration. The values of temperature, humidity and CO2 concentration in upwind area were low, and the environment in downwind area was not favorable for crop growing. Generally, the predicted values were a little lower than those of the measured, while the trend was similar. The relative error values of temperature, humidity and CO2 concentration were less than 8%, 6% and 7%, respectively. Number of references:17 Main heading:Carbon dioxide Controlled terms:Atmospheric composition - Atmospheric humidity - Computational fluid dynamics - Cultivation - Greenhouses - Monte Carlo methods - Oceanography - Soils - Sun - Temperature Uncontrolled terms:Distribution of temperature - Environmental model - Generalized analysis - Plastic greenhouse - Shear-stress transport - Steady simulation - Three dimensional simulations - Ventilation patterns Classification code:443.1 Atmospheric Properties - 471.1 Oceanography, General - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 657.2 Extraterrestrial Physics and Stellar Phenomena - 804.2 Inorganic Compounds - 821.3 Agricultural Methods - 821.6 Farm Buildings and Other Structures - 921.6 Numerical Methods - 922.2 Mathematical Statistics DOI:10.6041/j.issn.1000-1298.2014.09.048 Database:Compendex 11. Accession number:201442113312 Title:Effects of blade tip shape on cavitating flow in axial flow pumps Authors:Shi, Weidong1 ; Wu, Suqing1 ; Zhang, Desheng1 ; Yao, Jie1 ; Cheng, Cheng1 Author affiliation:1 Research Center of National Pump and System Engineering Technology, Jiangsu University, Zhenjiang, China Corresponding author:Shi, Weidong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:101-106 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Tip leakage vortex in axial flow pump mainly caused by the rolling of the main flow and leakage flow from the tip clearance between blade tip and end wall is the main cause of the tip leakage vortex cavitation and blade tip cavitation erosion. In order to find an appropriate tip shape to control and reduce TLV cavitation, experimental results, from high-speed photography cavitation test, and numerical results were compared to validate the correctness of the simulation. Then on the basis of original plane tip shape, the cavitation performance of the other three tip shapes, rounding, chamfered, and rounding chamfered, were studied by simulation. Fluid domain was calculated by structural mesh so as to get fluid characteristic in tip clearance region, precisely. The results show that the rounding tip and rounding chamfered tip make head and efficiency decline while the chamfered tip makes them raise a little. Although the rounding tip eliminates the corner vortex cavitation, it makes TLV cavitation worse. The chamfered tip is in contrast to the rounding tip, and there is cavitation existing in clearance. The rounding chamfered tip does well in controlling corner vortex cavitation and TLV cavitation simultaneously, compared with the others. The study suggests the rounding chamfered tip scheme can be adopt to control the tip cavitation, if the cavitation performance is the primary factor. Number of references:19 Main heading:Cavitation Controlled terms:Axial flow - High speed photography - Leakage (fluid) - Pumps - Vortex flow Uncontrolled terms:Axial flow pump - Blade tip - Cavitating - Cavitation performance - Numerical results - Tip leakage vortex - TLV - Vortex cavitation Classification code:452.3 Industrial Wastes - 618.2 Pumps - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 742.1 Photography DOI:10.6041/j.issn.1000-1298.2014.09.017 Database:Compendex 12. Accession number:201442113339 Title:Three dimensional reconstruction of maize ear based on computer vision Authors:Wang, Chuanyu1 ; Guo, Xinyu1 ; Wu, Sheng1 ; Xiao, Boxiang1 ; Du, Jianjun1 Author affiliation:1 Beijing Research Center for Information Technology in Agriculture, Beijing, China Corresponding author:Guo, Xinyu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:274-279 and 253 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:An approach for rapid, accurate and automatic 3D reconstruction of maize ear based on computer vision was presented. Firstly, we rotate the maize ear in a proper angle interval to acquire images in different views, and then calculate out points cloud of maize ear surface with binocular stereovision. Secondly, we eliminate outliers according to the threshold of reprojection error, find out 2D matching points in two neighboring images, determine the 3D matching points set of points clouds of maize ear surfaces by the 2D matching points, calculate the rotation matrix and translation vector of the matching points between two neighboring views, and test the consistency of the 3D registration model by RANSAC method. Finally, by rotating and translating each point cloud of different views to stitch the whole maize ear surface, eliminating the redundant points, simplifying the mesh, and mapping the texture, we get the final 3D shape of maize ear. The experiment results show that the volume of the 3D reconstruction maize ear has no significant difference from the measurement value, and the method proposed can meet the need of 3D reconstruction of maize ear. Number of references:19 Main heading:Stereo image processing Controlled terms:Computer vision - Stereo vision Uncontrolled terms:3D reconstruction - 3D registration - Binocular stereo vision - Maize ears - RANSAC - SIFT Classification code:723.5 Computer Applications DOI:10.6041/j.issn.1000-1298.2014.09.044 Database:Compendex 13. Accession number:201442113325 Title:Characteristics and influencing factors of soil anti-scourability during maize growing season Authors:Zheng, Zicheng1 ; Zhang, Xizhou1 ; Li, Tingxuan1 ; Jin, Wei1 ; Lin, Chaowen2 Author affiliation:1 College of Resources and Environment, Sichuan Agricultural University, Chengdu, China 2 Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China Corresponding author:Zheng, Zicheng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:180-186 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Soil anti-scourability is one of the important parameters for evaluating the ability of soil resistance to soil erosion. In order to explore the characteristics of soil anti-scourability, dynamic change and influence factors of soil anti-scourability were studied during maize growing season by using the method of the undisturbed soil sample washing experiment and laboratory analysis. The results showed that sediment concentration decreased first and then gradually became a balanced developing state with the prolonging washing time during the maize growth season under the condition of different sloping degrees. The sediment concentration reached the highest value under the condition of 15°. With the growing of maize, soil anti-scourability and enhancement effect increased gradually and reached the maximum in the mature period. With the increase in slope, the enhancement effect of maize root on soil anti-scourability decreased gradually. Soil anti-scourability positively correlated with soil bulk density, organic matter content and >2 mm water-stable aggregates significantly, but negatively correlated with <0.25 mm water-stable aggregates. Soil anti-scourability was significantly correlated with the root content, root surface area, root volume, and total root length. Therefore, it had great significance for guiding comprehensive control of soil erosion to select the maize varieties with <0.5 mm root systems, and applying soil and water conservation measures to increase soil organic matter content and water-stable aggregates. The results could provide theoretical guidance to soil erosion control in purple soil areas. Number of references:17 Main heading:Soil conservation Controlled terms:Aggregates - Biogeochemistry - Biological materials - Chemicals removal (water treatment) - Cultivation - Erosion - Forestry - Organic compounds - Sedimentation - Soils - Washing - Water conservation Uncontrolled terms:Anti-scourability - Comprehensive controls - Influencing factors - Maize - Organic matter content - Purple soils - Soil and water conservation measures - Soil organic matter contents Classification code:406 Highway Engineering - 407 Maritime and Port Structures; Rivers and Other Waterways - 444 Water Resources - 461.2 Biological Materials and Tissue Engineering - 481.2 Geochemistry - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.0 Woodlands and Forestry - 821.3 Agricultural Methods DOI:10.6041/j.issn.1000-1298.2014.09.030 Database:Compendex 14. Accession number:201442113331 Title:Research on meat thickness measurement based on laser double-triangulation method Authors:Hong, Guan1, 2 ; Zhao, Maocheng1 ; Wang, Xiwei1 ; Shang, Qingqing1 ; Ju, Ronghua3 ; Wu, Zhiwei1 Author affiliation:1 College of Electronic and Mechanical Engineering, Nanjing Forestry University, Nanjing, China 2 Nanjing Institute of Railway Technology, Nanjing, China 3 Nanjing Food and Packaging Machinery Institute, Nanjing, China Corresponding author:Zhao, Maocheng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:223-229 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Food foreign bodies harm the human health and hold back the food industry development. To detect food by computer vision and image processing technology, the examination has the advantages of non-destruction, high-speed, accuracy and reliable etc. The meat thickness on-line real-time detection system was first designed and constructed, which collected X-ray image of meat and laser image of meat, including filtering, enhancement and other image preprocessing. The X-ray image system of irregular meat was affected by the gray deviations of uneven thickness of meat. A meat thickness measurement method by laser triangular was proposed to eliminate the gray deviations of the X-ray image of the uneven thickness meat. This study established the mathematical model for the thickness of irregular meat, and a thickness measurement system by symmetrical structure of the laser double-triangulation method. Through calibration method two laser image collected by CCD camera were unified by means of the same coordinates. The meat images were synthesized using the image integration methods based on both gray scale method. The three-dimensional scanning experimental result show that the external shape of meat with corresponding profile, gray variation, and the variational thickness of meat image are close to meat thickness. Number of references:18 Main heading:Meats Controlled terms:CCD cameras - Computer vision - Image processing - Surveying - Thickness gages - Thickness measurement - Triangulation - X ray analysis - X rays Uncontrolled terms:Double-triangulation method - Foreign substances - Image preprocessing - Image processing technology - Real-time detection - Symmetrical structure - Thickness compensation - Three-dimensional scanning Classification code:405.3 Surveying - 421 Strength of Building Materials; Mechanical Properties - 423.1 Non Mechanical Properties of Building Materials: Test Equipment - 714.2 Semiconductor Devices and Integrated Circuits - 741 Light, Optics and Optical Devices - 741.2 Vision - 801 Chemistry - 822.3 Food Products - 932.1 High Energy Physics - 943.2 Mechanical Variables Measurements - 951 Materials Science DOI:10.6041/j.issn.1000-1298.2014.09.036 Database:Compendex 15. Accession number:201442113314 Title:Numerical study of swirling flow fields in francis turbine under small opening condition Authors:Guo, Tao1 ; Zhang, Lixiang1 Author affiliation:1 Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, China Corresponding author:Guo, Tao Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:112-118 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The phenomenon that strong vibration of units occurred when the Francis turbine is operating under the small opening conditions, such as Gongzu, Shiquan, Liujia Gorges, Lijia Gorges and Three Gorges project. It was used the large eddy simulation (LES) method based on Vreman SubGrid-Scale model to analysis the generation and evolution process of turbulence flow, captured the details of the flow structures and the dissipation of the turbulent kinetic energy. The SIMPIEC algorithm was applied to solve the coupled equation of velocity and pressure. The result shows that the small guide opening conditions deviated from the optimal conditions mostly. The unstable flow phenomenon including the swirl, flow separation, interruption and reflux was strong and complicated, which led to the abnormal vibration of the units. Number of references:19 Main heading:Francis turbines Controlled terms:Kinetic energy - Kinetics - Large eddy simulation - Swirling flow - Turbulence Uncontrolled terms:Abnormal vibration - Large Eddy simulation methods - Small opening flow - Sub-grid scale models - Three Gorges project - Turbulence characteristics - Turbulent kinetic energy - Vortex rope Classification code:617.1 Hydraulic Turbines - 631 Fluid Flow - 631.1 Fluid Flow, General - 921 Mathematics - 931.1 Mechanics DOI:10.6041/j.issn.1000-1298.2014.09.019 Database:Compendex 16. Accession number:201442113299 Title:Research on all-terrain profiling crawler power chassis Authors:Zhao, Jianzhu1 ; Wang, Fengchen1 ; Yu, Bin1 ; Wang, Decheng1 Author affiliation:1 College of Engineering, College of Engineering, Beijing, China Corresponding author:Wang, Decheng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:20-24 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:To develop the passing ability and the ride comfort of crawler power chassis, a set of new suspension system was designed. Each suspension system has 5 separate damping units, and each one includes a hydraulic cylinder and a coil spring. The mathematic model was built according to the structure and mechanical properties of damping units. It was revealed from Keq-H curve drawn from the mathematic model that the suspension system had nonlinear stiffness characteristic. 1:4 crawler power chassis prototype and the performance tests were made. The chassis could achieve all-terrain profiling and its maximum grade ability was about 60%, its maximum speed was about 3 km/h. From the vibration acceleration curve, the absolute value of vibration acceleration was lower than 2.0 m/s2. The crawler power chassis with new suspension system is good in its passing ability and ride comfort. Number of references:12 Main heading:Suspensions (components) Controlled terms:Agricultural machinery - Chassis - Damping - Hydraulic machinery - Mechanical properties Uncontrolled terms:Crawler - Hydraulic cylinders - Mathematic model - Non-linear stiffness - Performance tests - Profiling - Suspension system - Vibration acceleration Classification code:601.2 Machine Components - 632.2 Hydraulic Equipment and Machinery - 663.2 Heavy Duty Motor Vehicle Components - 821.1 Agricultural Machinery and Equipment - 931.1 Mechanics DOI:10.6041/j.issn.1000-1298.2014.09.004 Database:Compendex 17. Accession number:201442113342 Title:Path loss modeling for 2.4 GHz wireless channel in wheat fields Authors:Zhang, Haihui1 ; Zhang, Jiaming1 Author affiliation:1 College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; Shaanxi, China Corresponding author:Zhang, Haihui Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:291-296 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:As path loss modeling for wireless channel is an essential issue for applications of wireless sensor network in wheat fields, 4 kinds of path loss modeling methods were studied and their adaptability was analyzed. Firstly, path loss of 2.4 GHz wireless signals was measured by wireless sensor modules in wheat fields, and the trend of path loss was analyzed. Then the measured data were compared with the path loss predicted by the free space model and the two-ray model respectively. A modified two-slope log-distance model was proposed and then the one-slope log-distance model and the modified two-slope log-distance model were applied to perform regressions for the measured data of path loss based on the least square method respectively. The results show that there were big differences between the path loss predicted by the first two models and the measured data, and thus the first two models couldnot be used to predict path loss directly in the environment. The R2 values of the latter two models were 0.879 and 0.943 and the standard error of the estimate were 3.242 and 2.229 respectively, which indicated both of the two models were applicable for path loss modeling in wheat fields and the modified two-slope log-distance model had a better accuracy. Number of references:21 Main heading:Wireless sensor networks Controlled terms:Least squares approximations Uncontrolled terms:2.4 ghz wireless channels - Least square methods - Path loss models - Standard errors - Wheat fields - Wireless channel - Wireless sensor - Wireless signals Classification code:732 Control Devices - 921.6 Numerical Methods DOI:10.6041/j.issn.1000-1298.2014.09.047 Database:Compendex 18. Accession number:201442113323 Title:Multi-objective optimization model of planting structure based on two-level fractional programming Authors:Li, Mo1 ; Guo, Ping1 Author affiliation:1 College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China Corresponding author:Guo, Ping Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:168-174 and 130 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A multi-objective optimization model of planting structure was developed by incorporating fractional programming and two-level programming. The proposed model was solved by interactive fuzzy programming. Two advantages the proposed planting structure model has two advantages: the maximum planting benefit with the minimum of irrigation water could be obtained quantificationally, and the subjectivity was avoided in the previous multi-objective optimization models; the optimal planting structure could be obtained by integrating the decisions from both the upper level and lower level in the study areas. The proposed model and the corresponding solution method were applied to the planting structure optimization in the middle reaches of Black River. The optimal results of planting structure were obtained, and the comparison between the optimal results and the actual results was also made. It shows that the planting benefit per unit of water increased by 1.94 yuan/m3, with the whole planting benefit increasing by 3.2×108 yuan, and the total water consumption decreased by 1.3×109 m3. The obtained results verified the feasibility of the model and its calculation method. The model and the corresponding results will provide theoretical basis and decision support to the study and similar areas. Number of references:21 Main heading:Multiobjective optimization Controlled terms:Decision support systems - Fuzzy systems - Irrigation - Mathematical programming - Optimization - Shape optimization - Structural optimization - Water supply Uncontrolled terms:Corresponding solutions - Fractional programming - Interactive fuzzy programming - Irrigation waters - Multi-objective optimization models - Structure modeling - Structure optimization - Two-level programming Classification code:446.1 Water Supply Systems - 723 Computer Software, Data Handling and Applications - 821.3 Agricultural Methods - 921.5 Optimization Techniques - 961 Systems Science DOI:10.6041/j.issn.1000-1298.2014.09.028 Database:Compendex 19. Accession number:201442112894 Title:Calculation method of minimum length retained in cylinder for swash-plate plunger pump based on energy loss Authors:Cheng, Huanbo1 ; Liu, Zhifeng1 ; Xie, Ping2 ; Zhan, Yifei1 ; Yuan, He1 Author affiliation:1 School of Mechanical and Automotive Engineering, Hefei University of Technology, Hefei, China 2 Guangxi Liugong Machinery Co. Ltd., Liuzhou, China Corresponding author:Liu, Zhifeng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:333-339 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Based on the energy loss analysis of the sliding pair between plunger and cylinder, a mathematical model of overall efficiency loss was established. Based on the principle of minimum overall efficiency loss, a calculation method of minimum length retained in cylinder was proposed. In order to ensure the plunger was not stuck during the relative movement because of friction self-locking, a strength check method of the sliding pair was proposed to validate the rationality of the calculated minimum length. And according to the strength check method, the minimum length and corresponding plunger geometry length were calculated. Under the principle of minimum loss of total efficiency, the optimum clearance of sliding pair was calculated by the strength check method. A case analyzed and verified the correctness of the calculation method, the calculated minimum length is 35 mm or 40 mm for the plunger pump used on an engineering machinery, the corresponding optimal clearance is 0.012 mm or 0.0127 mm, and the theoretical calculated overall efficiency loss is 0.3%. Number of references:12 Main heading:Cylinders (shapes) Controlled terms:Energy dissipation - Locks (fasteners) - Machinery - Pumps Uncontrolled terms:Check method - Energy loss analysis - Engineering machinery - Optimum clearance - Overall efficiency - Plunger pumps - Relative movement - Total efficiency Classification code:408.2 Structural Members and Shapes - 525.4 Energy Losses (industrial and residential) - 601 Mechanical Design - 601.3 Mechanisms - 618.2 Pumps DOI:10.6041/j.issn.1000-1298.2014.09.054 Database:Compendex 20. Accession number:201442112892 Title:Design and test of lamina emergent mechanisms S-shaped flexure hinge Authors:Qiu, Lifang1 ; Meng, Tianxiang1 ; Zhang, Jiuqiao1 ; Yang, Debin1 Author affiliation:1 School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China Corresponding author:Yang, Debin Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:324-328 and 323 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Part of the challenge in designing LEMs (Lamina emergent mechanisms) comes in designing the suitable flexure hinges. A new S-shaped flexure hinge used on LEMs was proposed and its structure was designed. The bending stiffness equivalent and torsion stiffness equivalent of the S-shaped flexure hinge was presented. By theoretical calculation and finite element simulation analysis of the design example, the correctness of the calculation formula and simulation models was verified. The LEMs slider mechanism base on S-shaped flexure hinge was produced. The FEA model and test results prove that this mechanism can produce large deformation with high accuracy in operating state, when the displacement of slider reached to 76 mm, the FEA and test results are basically the same, the deviation between them is 0.76%. Number of references:19 Main heading:Hinges Controlled terms:Compliant mechanisms - Finite element method - Stiffness Uncontrolled terms:Bending stiffness - Calculation formula - Equivalent stiffness - Finite element simulations - Flexure hinge - Lamina emergent mechanisms - LEMs - Theoretical calculations Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 605 Small Tools and Hardware - 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science DOI:10.6041/j.issn.1000-1298.2014.09.052 Database:Compendex 21. Accession number:201442113327 Title:Influence of acid hydrolysis on total sugar determination in sweet sorghum by DNS method Authors:Zhang, Chengming1, 2 ; Jiang, Li1, 2 ; Li, Shizhong1, 2 Author affiliation:1 Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China 2 Beijing Engineering Research Center of Biofuels, Beijing, China Corresponding author:Li, Shizhong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:199-203 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The reason of the influence of acid hydrolysis on total sugar determination in sweet sorghum by 3, 5-dinitrosalicylicacid method was analyzed. Fructose could completely degrade when the ratio of 6 mol/L hydrochloric acid to sugar liquid was 21 in a boiling water bath for 30 min. Under such conditions, the measured values of glucose, fructose and sucrose by DNS method were 100%, 2.5% and 52.2% of the corresponding theoretical values. Meanwhile, the fructose solution after hydrolysis appeared a pseudo-peak of glucose in the HPLC chromatogram, which caused glucose value higher than the real value. The determination of fructose and sucrose was impacted by the acid concentration, hydrolysis time and hydrolysis temperature. Fructose degradation during the acid hydrolysis caused the measurement error in the total sugar determination in sweet sorghum by DNS method. When determinate total sugar content in raw material contained fructose and sucrose by DNS method, it should ensure the complete hydrolysis of sucrose, and no degradation of fructose, otherwise it would result in inaccurate measurement. Number of references:9 Main heading:Liquid sugar Controlled terms:Chromatographic analysis - Fructose - Glucose - Hydrolysis - Sugar (sucrose) - Supersonic aerodynamics Uncontrolled terms:3, 5-dinitrosalicylicacid - Acid hydrolysis - Sucros - Sweet sorghum - Total sugars Classification code:651.1 Aerodynamics, General - 801 Chemistry - 802.2 Chemical Reactions - 822.3 Food Products DOI:10.6041/j.issn.1000-1298.2014.09.032 Database:Compendex 22. Accession number:201442113302 Title:Modeling and experiment of electronic injector of high pressure common rail fuel injection system Authors:He, Zhongbo1 ; Xue, Guangming1 ; Li, Dongwei1 ; Yang, Zhaoshu1 Author affiliation:1 Department of Vehicles and Electrical Engineering, Ordnance Engineering College, Shijiazhuang, China Corresponding author:He, Zhongbo Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:37-43 and 19 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The model of solenoid valve injector in high pressure common rail system is presented. The model considers the influences of flow limiting valve, T type pipe and the pressure loss caused by fuel flow. The forms and positions of the pressure loss were determined. In the model the fuel density and elastic modulus are only viewed as the functions of fuel pressure. The results obtained by Simulink software were compared with experimental results in order to assess the model. Results show that the simulation error of the model considering flow limit valve and T type pipe influences to the experimental results is less than 6%, while the results without these considerations have larger difference from the experimental results. The simulation difference between the model that views fuel density and elastic modulus as constants and the model that views both of them as the functions of pressure is small. The errors of the two models to the experimental results are less than 6%. Number of references:11 Main heading:Fuel injection Controlled terms:Diesel engines - Elastic moduli - Engines - Fuels - Mathematical models - Solenoid valves Uncontrolled terms:Electronic fuel injectors - Flow-limiting valves - High pressure common rail - High pressure common rail fuel injection system - High pressure common rail system - Pressure loss - Simulation error - Simulink software Classification code:421 Strength of Building Materials; Mechanical Properties - 521 Fuel Combustion and Flame Research - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 612 Engines - 612.2 Diesel Engines - 619 Pipes, Tanks and Accessories; Plant Engineering Generally - 921 Mathematics - 951 Materials Science DOI:10.6041/j.issn.1000-1298.2014.09.007 Database:Compendex 23. Accession number:201442113334 Title:Real-time monitoring system for paddy environmental information based on wireless sensor network Authors:Sun, Baoxia1, 2 ; Wang, Weixing1, 3 ; Lei, Gang1 ; Hong, Bingxing1 ; Zhang, Xiong1 Author affiliation:1 College of Engineering, South China Agricultural University, Guangzhou, China 2 Guangdong Engineering Polytechnic College, Guangzhou, China 3 Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China Corresponding author:Wang, Weixing Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:241-246 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:In view of the characteristics of long monitoring period and great environmental interference in the process of farmland environmental data collection, a wireless sensor network real-time monitoring system for paddy environmental information based on hybrid antenna was designed, used cluster routing protocol to networking, configured different types of antennas for different types of nodes, and a turntable was used to control the direction of the directional antenna sink node to expand the coverage of the network and improve the stability of the system. The networking experiment was carried out in paddy based on the system for a long time, and the network packet loss rate and the acquisition accuracy of paddy environmental parameter were tested, the test results show that the system runs stably and the measurements are accurate, the average network data packet loss rate is 0.44%, and the average relative error of paddy air temperature, air humidity and soil moisture content are 0.26%, 0.64% and 0.33% respectively. Number of references:15 Main heading:Wireless sensor networks Controlled terms:Antennas - Directive antennas - Monitoring - Packet loss - Sensor nodes - Soil moisture - Soil surveys - System stability Uncontrolled terms:Average relative error - Directional Antenna - Environmental information - Environmental interference - Environmental parameter - Hybrid antenna - Paddy - Real-time monitoring systems Classification code:483.1 Soils and Soil Mechanics - 716 Telecommunication; Radar, Radio and Television - 722 Computer Systems and Equipment - 732 Control Devices - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 961 Systems Science DOI:10.6041/j.issn.1000-1298.2014.09.039 Database:Compendex 24. Accession number:201442113340 Title:Touching corn kernels based on skeleton features information Authors:Niu, Jie1, 2 ; Bu, Xiongzhu1 ; Qian, Kun3 Author affiliation:1 School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing, China 2 School of Electrical and Electronic Engineering, Changzhou College of Information Technology, Changzhou, China 3 School of Automation, Southeast University, Nanjing, China Corresponding author:Bu, Xiongzhu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:280-284 and 290 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The segmentation method based on Watershed algorithm is inefficient when the object has a much higher aspect ratio. This paper presents an automatic separation procedure of touching kernel images based on their skeleton features. First the images were preprocessed by the vector median filter to get the smoothing images. Then the improved single-pass thinning algorithm was adopted to abstract binary image skeleton. After getting the pose of possible adhesive points with SPT algorithm, each endpoint of skeleton lines concluded and corrected recursively according to the direction and distance. The algorithm was tested for different grain types under different touching scenarios and was successful in separating more than 90% of the touching grains when classical watershed methods allow only to segment 25% of the high length to width ratio (>1.5) grains. The algorithm appears to be robust to separate touching scenarios where the kernels have different length-width ratio. Number of references:16 Main heading:Image segmentation Controlled terms:Algorithms - Aspect ratio - Median filters - Musculoskeletal system - Watersheds Uncontrolled terms:Automatic separations - Length-to-width ratio - Length-width ratios - Segmentation methods - Skeleton - Touching kernels - Vector median filters - Water-shed algorithm Classification code:444.1 Surface Water - 461.3 Biomechanics, Bionics and Biomimetics - 703.2 Electric Filters - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 921 Mathematics - 943 Mechanical and Miscellaneous Measuring Instruments DOI:10.6041/j.issn.1000-1298.2014.09.045 Database:Compendex 25. Accession number:201442113322 Title:Effects of saline water irrigation on soil water-heat-salt variation and cotton yield and quality Authors:Zhang, Junpeng1 ; Feng, Di1 ; Zheng, Chunlian2 ; Sun, Chitao1 ; Sun, Jingsheng1 ; Gao, Yang1 Author affiliation:1 Ministry of Agriculture, Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, China 2 Institute of Dryland Farming, Hebei Academy of Agriculture and Forestry Sciences, Hengshui, China Corresponding author:Sun, Jingsheng Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:161-167 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:To make full use of saline water resources, the effects of irrigation with saline water of different salinity on soil water-heat-salt variation, cotton growth, yield and fiber quality were studied by field contrast experiment. The irrigation water salinities of four treatments were 1 (S1), 3 (S2), 5 (S3), 7 g/L (S4), respectively. Results show that the soil water content in depth of 0~40 cm and the temperature at 5cm soil layer have little differences under every treatment during the cotton growing period. Both of them increase with the salinity. The differences of soil electrical conductivity in the treatments are significant. The higher salinity of irrigation water, the higher the soil electrical conductivity is. The leaching efficiency of rainfall on soil salt is 29.40%~40.40% under each treatment at the end of cotton growth. The profile distribution of soil water and salt are restrained by soil texture, rainfall and water consumption due to cotton evapotranspiration. In drought time, soil is dry and salt accumulates in surface. But in wet period the results are opposite. The seedling rate, plant height, largest leaf area per plant and pro-frost yield of cotton decrease with the irrigation water salty rise. The cotton yields of the treatments from high to low are S2, S1, S3, S4, respectively, among which the difference between S4 and S1 treatments reaches significant level. Saline water irrigation produced a negative impact on fiber quality by changing Mic value, especially for S4 treatment. The study provides an important theoretical support for developing saline water irrigation of cotton. Number of references:20 Main heading:Saline water Controlled terms:Cotton - Cultivation - Electric conductivity - Image quality - Irrigation - Rain - Soil moisture - Soils - Water - Water resources - Water supply Uncontrolled terms:Contrast experiment - Irrigation waters - Profile distributions - Saline water irrigations - Soil electrical conductivity - Soil water content - Water-heat-salt - Yield Classification code:443.3 Precipitation - 444 Water Resources - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 701.1 Electricity: Basic Concepts and Phenomena - 741 Light, Optics and Optical Devices - 821.3 Agricultural Methods - 821.4 Agricultural Products DOI:10.6041/j.issn.1000-1298.2014.09.027 Database:Compendex 26. Accession number:201442113318 Title:Jet-wake flow in the channel of impeller and the effect of surface roughness on it Authors:Zhao, Binjuan1 ; Wang, Yu1 ; Chen, Huilong1 ; Hou, Duohua1 ; Qiu, Jing1 Author affiliation:1 School of Energy and Power Engineering, Jiangsu University, Zhenjiang, China Corresponding author:Zhao, Binjuan Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:138-143 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:For analyzing the flow pattern and reducing the hydraulic loss, the jet-wake flow in the channel of impeller and how it is influenced by the surface roughness have been studied by coupling computational fluid mechanics and the sand-grain roughness method. The results of experiment and simulation were compared to insure the RNG k-Ε model could reflect the variation of the inner flow. The results indicate that the jet-wake flow was obvious in the channel of impeller and the jet flow mainly appeared nearby the rear shroud of the suction side, while the jet flow appeared in the front shroud at the exit of impeller. The surface roughness of the impeller had a great influence on the relative velocity, and had the opposite influence on the pressure and suction side. The effect of surface roughness on the relative velocity become opposite when the value of roughness was higher than a transitional point. With the increase of the value of surface roughness, the amplitude of the relative velocity at the exit of impeller increased obviously, which was caused by the impeller-volute interaction. Number of references:16 Main heading:Surface roughness Controlled terms:Centrifugal pumps - Computer simulation - Fluid mechanics - Impellers - Wakes Uncontrolled terms:Computational fluid mechanics - Hydraulic loss - Inner flow - Jet flow - Jet-wake flows - Relative velocity - Suction side Classification code:601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 723.5 Computer Applications - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids DOI:10.6041/j.issn.1000-1298.2014.09.023 Database:Compendex 27. Accession number:201442113335 Title:Development of handheld terminal for sheep breeding information management based on RFID and ZigBee Authors:Wang, Ling1 ; Zou, Xiaoyu1 ; Liu, Siyao1 ; Shen, Mingxia1 ; Zhu, Hongchao1 ; Zhu, Rongjie1 Author affiliation:1 Jiangsu Province Engineering Lab. for Modern Facility Agriculture Technology & Equipment, Nanjing Agricultural University, Nanjing, China Corresponding author:Wang, Ling Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:247-253 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:In order to select the sheep with better characters than others into the core group, a handheld terminal, used for sheep breeding information management, was developed by combining RFID, ZigBee wireless communication and ARM. The handheld terminal was mainly designed with ARM core board based on S3C6410 processor, 125 kHz RFID reader, ZigBee wireless communication module based on CC2530 chip and multi-functional baseboard. In the process of software development, the embedded Linux system environment with the hardware device drivers mentioned above were established. ARM was used to receive real-time RFID reader data by using Qt/Embedded signal/slot. Through running ZigBee2007 protocol stack under the OSAL operating system, the communication was realized between ARM and ZigBee network. Some background application programs, such as the touch screen interface and serial communication, communication instruction, soft keyboard, buzzer, Chinese display etc., were designed based on Qt, which had functions of daily management, breeding management and disease management. Field test results showed that the handheld terminal could collect, enter, store, copy and query sheep breeding information in real-time, and communicate with the host computer through ZigBee wireless network. It was proved that the developed system could meet the needs of sheep information management. Number of references:20 Main heading:Information management Controlled terms:Application programs - ARM processors - Computer operating systems - Software design - Touch screens - Wireless sensor networks - Wireless telecommunication systems - Zigbee Uncontrolled terms:Communication instructions - Embedded linux system - Embedded technology - Hand-held terminals - Serial communications - Touch screen interface - ZigBee wireless communication - ZigBee wireless networks Classification code:716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 721 Computer Circuits and Logic Elements - 722.2 Computer Peripheral Equipment - 722.3 Data Communication, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 903.2 Information Dissemination DOI:10.6041/j.issn.1000-1298.2014.09.040 Database:Compendex 28. Accession number:201442113296 Title:AMT shift system based on direct-drive and self-energizing technology Authors:Ge, Wenqing1 ; Li, Bo1 ; Zhao, Yanjun2 ; Liu, Zeyan1 Author affiliation:1 School of Transportation and Vehicle Engineering, Shandong University of Technology, Zibo, China 2 School of Mechanical Engineering, Shandong University of Technology, Zibo, China Corresponding author:Ge, Wenqing Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:1-7 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:In order to further improve shifting quality and system robustness of automated manual transmission (AMT), an AMT system program based on direct-drive and self-energizing shifting system is given. These technical measures can improve the compactness of the system and the shift quality of AMT, at the same time, the shifting energy loss happening in the process of gear switching is reduced greatly. The key technologies of shift system based on direct-drive technology are researched by theoretical analysis, simulation and experiment in this thesis. The structure of direct-drive device is designed, and then, the performance tests have been completed. To solve the inherent problems of direct-drive technology, a servo synchronizer with the function of self-energizing and improving the shifting system robustness is studied. The principle prototype of self-energizing shifting system is developed reference to real vehicle parameters. The universal test bench for AMT shift system based on 2-DOF EMA has been constructed. The feasibility, functionality and versatility of AMT shift system based on direct-drive technology are verified in the last. The results show that the maximum instantaneous force provided by self-energizing shifting system is smaller than traditional shifting system in the same shifting quality, and the shifting energy loss can be reduced greatly. The force amplification coefficient nF is nearly 1.54 when the energizing bevel angle θ is equal to 116°. For the direct-drive automated mechanical transmission, the upshift time is controlled in nearly 150 ms and the synchronization time is controlled at 105 ms when the rotary speed difference is 500 r/min, the moment of inertia is 0.04 kg·m2 and the maximum instantaneous force reaches 770N. At this moment, the maximum instantaneous force provided by shift driving device of direct-drive and self-energizing shift system is 500 N, it has been reduced nearly 35%. Thus, the functions of amplifying force output by driving device and improving the shifting system robustness are implemented. It has laid a good technical foundation for decreasing the volume of driving device and reducing the difficulty of shifting control system design. Number of references:16 Main heading:Transmissions Controlled terms:Automation - Energy dissipation - Industrial management - Robustness (control systems) - Speed control - Structure (composition) - Synchronization Uncontrolled terms:Automated manual transmission - Automated mechanical transmissions - Direct drive - Force amplification - Moment of inertia - Shifting controls - Synchronization time - Technical measures Classification code:525.4 Energy Losses (industrial and residential) - 602.2 Mechanical Transmissions - 731 Automatic Control Principles and Applications - 732 Control Devices - 912.2 Management - 951 Materials Science DOI:10.6041/j.issn.1000-1298.2014.09.001 Database:Compendex 29. Accession number:201442113337 Title:Prediction model of plant leaf wilting using 3-D machine vision Authors:Zhang, Xin1 ; Zhao, Yandong1 ; Zheng, Lijia2 ; Kraft, Martin3 Author affiliation:1 School of Technology, Beijing Forestry University, Beijing, China 2 College of Information and Electrical Engineering, China Agricultural University, Beijing, China 3 Thuenen Institute of Agricultural Technology, German Federal Research Institute for Rural Areas, Forestry and Fisheries, Braunschweig, Germany Corresponding author:Zhao, Yandong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:260-267 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Wilting of plants appears when the water supply of plants is insufficient. Quantitative identification of wilting phenomena of plant stems, leaves and other parts is of important practical significance to improve agricultural production and efficient water irrigation. A scanning device based on the principle of laser ranging oblique is used to obtain real-time 3-D plant images. Then leaf curl statistical index, fractal dimension and the DC component of two-dimensional Fourier spectrum were extracted as wilting index to quantify the degree of wilting plants. Three kinds of wilting indexes were tested on zucchini, gourds, pumpkins and okra leaves to find out the correlations with wilting extent. The experiments show that each wilting index had a good correlation with wilting extent (0.82 or more are reached). On this basis, a multiple linear regression model of three kinds of wilting indexes, vapor pressure deficit (VPD) and photosynthetically active radiation (PAR) was built. Number of references:16 Main heading:Plants (botany) Controlled terms:Agricultural machinery - Agriculture - Computer vision - Fractal dimension - Linear regression - Regression analysis - Water supply Uncontrolled terms:3-D image - Agricultural productions - Multiple linear regression models - Photosynthetically active radiation - Plant leaf - Quantitative identification - Vapor pressure deficit - Wilting index Classification code:446.1 Water Supply Systems - 461.9 Biology - 723.5 Computer Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 921 Mathematics - 922.2 Mathematical Statistics DOI:10.6041/j.issn.1000-1298.2014.09.042 Database:Compendex 30. Accession number:201442113344 Title:Influence of outline points on the recognition accuracy of fourier descriptors Authors:Zhao, Sanqin1 ; Liu, Deying1 ; Ding, Weimin1 ; Shen, Baoying1 Author affiliation:1 Engineering Laboratory of Modern Facility Agricultural Technology and Equipment in Jiangsu Province, Nanjing Agricultural University, Nanjing, China Corresponding author:Ding, Weimin Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:305-310 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The number of outline points is the only uncertain parameter when using Fourier descriptors (FDs) to identify or retrieve shapes. By choosing the shape outlines of circle, ellipse and rice planthopper forewings as study object, complex Fourier descriptors and elliptic Fourier descriptors as outline characteristics and intra-cluster similarity and inter-cluster similarity as evaluation indexes, the essential reason of influence of the outline points number on recognition accuracy was investigated and verified. Experimental result shows that intra-cluster similarity/circle boundary energy is changed with the number of boundary points, and thus changing recognition accuracy. And, when the boundary sampling points are more than 64, resampling has no effect on CFD recognition accuracy. However, both of the sampling and resampling point numbers have influence on EFD recognition accuracy. The advantage of CFD is that it can use at least 16 resampling boundary points to express the whole shape of an outline, while EFD needs more than 128 points, especially for identifying quite similar outlines. Number of references:15 Main heading:Fourier transforms Controlled terms:Animals - Uncertainty analysis Uncontrolled terms:Fourier descriptors - Outline points - Rice planthoppers - Shape recognition - Similarity Classification code:461 Bioengineering and Biology - 471 Marine Science and Oceanography - 814 Leather and Tanning - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822 Food Technology - 921.3 Mathematical Transformations - 922.1 Probability Theory DOI:10.6041/j.issn.1000-1298.2014.09.049 Database:Compendex 31. Accession number:201442113300 Title:Emission experiment on a chinese v diesel engine fueled with diesel/biodiesel Authors:Lou, Diming1 ; Kong, Deli1 ; Qiang, Qiang1 ; Hu, Zhiyuan1 ; Tan, Piqiang1 ; Zhou, Yi1 Author affiliation:1 School of Automobile, Tongji University, Shanghai, China Corresponding author:Lou, Diming Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:25-30 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:An experimental study was carried on a Chinese V diesel engine fueled with Chinese V diesel blended with waste cooking oil biodiesel. The correlation between the characteristics of biodiesel and regulated emissions was investigated. The result shows that when fueled with blended fuel, higher oxygen content of the blended fuel led to higher NOx emission, but the increased extent was not obvious. NOx emission of all fuel was highly correlated with high temperature combustion field and R2 of their logarithmic function fitting curve was more than 0.97. Higher oxygen content of blend fuels led to lower THC and CO emissions. THC and CO emissions were highly correlated with combustion duration and R2 of their power function fitting curve was more than 0.96. The total particle number and nuclei mode particle number were higher, and the accumulation mode particle number was lower. Higher nuclei mode particle number was related to higher viscosity and sulfur content, and lower accumulation mode particle number was related to higher oxygen content. Number of references:14 Main heading:Diesel engines Controlled terms:Biodiesel - Combustion - Curve fitting - Engines - Fuels - Oils and fats - Oxygen - Particulate emissions - Waste incineration Uncontrolled terms:Accumulation modes - Combustion duration - Emission standard - High-temperature combustion - Highly-correlated - Logarithmic functions - Regulated emissions - Waste cooking oil Classification code:451.1 Air Pollution Sources - 452.4 Industrial Wastes Treatment and Disposal - 521.1 Fuel Combustion - 523 Liquid Fuels - 612 Engines - 612.2 Diesel Engines - 804 Chemical Products Generally - 804.1 Organic Compounds - 921.6 Numerical Methods DOI:10.6041/j.issn.1000-1298.2014.09.005 Database:Compendex 32. Accession number:201442113311 Title:Multidisciplinary design optimization of axial-flow pump blades Authors:Tang, Fangping1 ; Shi, Lijian1 ; Lei, Cuicui1 ; Yang, Hua1 ; Yang, Fan1 Author affiliation:1 School of Hydraulic Energy and Power Engineering, Yangzhou University, Yangzhou, China Corresponding author:Tang, Fangping Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:96-100 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The design and optimization of axial-flow pump blades usually takes the hydraulic design as the principle, then takes strength check into consideration. That cannot achieve the goal of integrated optimization. The mathematical model of axial flow blades of multidisciplinary design optimization was established on the basis of the subject analysis and the coupling relation between hydraulic and structure subject. The mathematical model could achieve the targets of the highest efficiency of impeller and the lightest weight of blades by using collaborative optimization algorithm. The study shows that multidisciplinary design optimization could improve the overall performance of axial flow blades, which also meet the requirements that the axial is efficient and lightweight. The collaborative optimization algorithm for axial flow blades model of multidisciplinary design optimization is efficient and feasible. Number of references:10 Main heading:Distributed computer systems Controlled terms:Algorithms - Axial flow - Design - Design aids - Optimization - Pumps Uncontrolled terms:Axial flow pump - Blades - Collaborative optimization - Coupling relation - Design and optimization - Hydraulic designs - Integrated optimization - Multidisciplinary design optimization Classification code:618.2 Pumps - 631.1 Fluid Flow, General - 722.4 Digital Computers and Systems - 723 Computer Software, Data Handling and Applications - 902.1 Engineering Graphics - 921 Mathematics - 921.5 Optimization Techniques DOI:10.6041/j.issn.1000-1298.2014.09.016 Database:Compendex 33. Accession number:201442112895 Title:Flow resistance interference property of hemisphere-segment arranged in transverse for valve-less piezoelectric pump Authors:Ji, Jing1, 2 ; Zhang, Jianhui1 ; Chen, Daogen1 ; Zhao, Chunsheng1 Author affiliation:1 State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, China 2 College of Mechanical and Electrical Engineering, Qingdao Agricultural University, Qingdao, China Corresponding author:Zhang, Jianhui Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:340-346 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:In order to analyze the flow resistance property of the hemisphere-segment arranged in transverse for the valve-less piezoelectric pump with bluff-body and the influence of the hemisphere-segment on the output performance of the pump, the flow resistance action law of multiple hemisphere-segments arranged in transverse in pump chamber was studied. Based on the research of single hemisphere-segment flow resistance and the analysis of influence factors for hemisphere-segments arranged in transverse, the action laws of flow resistance interference coefficient and flow resistance coefficient for two hemisphere-segments arranged in transverse were obtained by experiments. Then the theoretical calculation of transverse flow resistance interference coefficient and flow resistance coefficient for multiple hemisphere-segments was derived. And the experiments on flow resistance and flow rate were carried out by using four hemisphere-segments arranged in transverse. The theoretical derivation was proved to be feasible for analyzing and predicting the flow resistance property and the flow rate of such valve-less piezoelectric pump with bluff-body. When the driving voltage was set to 120 V and driving frequency was set to 6 Hz, the flow rate of the pump reached to 44.78 mL/min. And the average deviation between theoretical and experimental was 39.34%. Number of references:22 Main heading:Pumps Controlled terms:Flow rate - Piezoelectric devices - Piezoelectricity Uncontrolled terms:Bluff body - Hemisphere-segment - Piezoelectric pump - Property analysis - Transverse arrangement Classification code:618.2 Pumps - 631 Fluid Flow - 701.1 Electricity: Basic Concepts and Phenomena - 704 Electric Components and Equipment - 714 Electronic Components and Tubes DOI:10.6041/j.issn.1000-1298.2014.09.055 Database:Compendex 34. Accession number:201442112891 Title:Elasto-dynamics optimal design of spatial parallel mechanism Authors:Chen, Xiulong1 ; Zhang, Zhonggong1 ; Deng, Yu1 Author affiliation:1 College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, China Corresponding author:Chen, Xiulong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:318-323 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The elasto-dynamics optimal design of 4-UPS-UPU 5-DOF spatial parallel mechanism was studied. The elasto-dynamic models of 4-UPS-UPU spatial parallel mechanism were established based on kineto-elasto dynamics. The total mass function and base frequency function of the parallel mechanism were integrated into a comprehensive optimization objective function, and the restrictive condition of the maximum deformation energy and the maximum dynamic stress of five driving limbs were considered as constraint equations to perform the optimal design. The optimized methods, such as fmincon function in matlab software and genetic algorithms were usedrespectively. The optimal parameters of the mass of moving platform and the sectional area of five driving limbs were determined based on the optimal design. And the correctness and rationality of the optimized method and results were verified. Number of references:15 Main heading:Dynamics Controlled terms:Design - Genetic algorithms - MATLAB - Mechanisms - Optimal systems Uncontrolled terms:Comprehensive optimizations - Constraint equation - Deformation energy - Elasto-dynamics - Optimal design - Parallel mechanisms - Restrictive conditions - Spatial parallel mechanism Classification code:408 Structural Design - 601.3 Mechanisms - 723 Computer Software, Data Handling and Applications - 921 Mathematics - 931.1 Mechanics - 961 Systems Science DOI:10.6041/j.issn.1000-1298.2014.09.051 Database:Compendex 35. Accession number:201442113338 Title:Maize leaf movement monitoring base on binocular stereo vision Authors:Wang, Chuanyu1 ; Guo, Xinyu1 ; Xiao, Boxiang1 ; Du, Jianjun1 ; Wang, Xiao1 Author affiliation:1 Beijing Research Center for Information Technology in Agriculture, Beijing, China Corresponding author:Guo, Xinyu Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:268-273 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A binocular stereo vision maize leaf motion monitoring system was proposed, the system includes a binocular camera, horizontal movement module, the vertical movement module, the image acquisition card, and a computer. The supporting structure holds camera above the measured maize leaf, and the camera is able to capture image pair at 30 f/s. An image processing program includes image acquisition, image pre-processing, markers extraction, sub-pixel edge refinement, 3D reconstruction and other modules. A fluorescent ball (diameter 0.35 cm) with high reflectivity was chosen as a marker, and its intensity is higher than the background environment which makes it easier to extract contour of ball out of background. The spherical marker will keep its circular shape more or less after perspective projection. In order to further improve the accuracy of stereo matching, a sub-pixel edge detection method based on gradient magnitude was adopted. In the simulation experiment, the camera was set away from the measured object about 50 cm, the system measurement deviation was 0.0139 cm, which is able to detect the small changes of leaf position. In field experiments, the actual measurement of the movement leaf caused by growth and physiological responses achieved the desired results. Number of references:18 Main heading:Stereo image processing Controlled terms:Cameras - Edge detection - Image acquisition - Image processing - Physiological models - Pixels - Stereo vision Uncontrolled terms:Background environment - Binocular stereo vision - Growth monitoring - Maize leaf - Perspective projections - Physiological response - Sub pixels - Subpixel edge detection Classification code:461.1 Biomedical Engineering - 716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 741 Light, Optics and Optical Devices - 741.2 Vision - 742.2 Photographic Equipment DOI:10.6041/j.issn.1000-1298.2014.09.043 Database:Compendex 36. Accession number:201442113305 Title:Positioning method for tea picking using active computer vision Authors:Zhang, Hao1 ; Chen, Yong1 ; Wang, Wei1 ; Zhang, Guolu1 Author affiliation:1 College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, China Corresponding author:Zhang, Hao Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:61-65 and 78 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:For the intelligent tea picking machine, the positioning of tea tips was a difficult procedure. A positioning method based on active computer vision and corresponding visual system were proposed to solve this problem. First, according to the characteristics of the tea picking surface, a cross light path of projection and camera was designed; then the recognition approach of tea tips based on the color factor was developed in natural environment; furthermore, fringe projection profilometry was studied to acquire the height information of tea tips. In fringe projection profilometry, the temporal phase unwrapping method was used to obtain the phase maps, the invalidity identification framework and morphological filter were designed to remove noise points, and a polynomial approximation method which can reduce the nonlinear error was applied to calculate the height. The experimental results show that the positioning system for tea tips based on fringe projection technology can effectively recognize the tips and extract their three-dimensional information, which can help new tea picking machine to realize the positioning function. Number of references:11 Main heading:Computer vision Controlled terms:Polynomial approximation - Profilometry - Projection systems Uncontrolled terms:Fringe projection profilometry - Morphological filters - Polynomial approximation methods - Positioning functions - Positioning methods - Tea - Temporal phase unwrapping - Three-dimensional information Classification code:723.5 Computer Applications - 741.3 Optical Devices and Systems - 921.6 Numerical Methods - 943.3 Special Purpose Instruments DOI:10.6041/j.issn.1000-1298.2014.09.010 Database:Compendex 37. Accession number:201442113341 Title:Method of image segmentation for touching maize kernels Authors:Liu, Guanyi1 ; Liu, Pingyi1 ; Wei, Wenjun1 ; Zhang, Shaoying1 ; Li, Haitao1 Author affiliation:1 College of Engineering, China Agricultural University, Beijing, China Corresponding author:Li, Haitao Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:285-290 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:With the aim to give a more accurate computing result of the maize kernel number based on image analysis, a new segmentation method for touching maize kernels was provided. First, contour smoothing and the Euclidean distance transformation were applied to the binary image of the touching kernels. Then the distance map was regarded as topographic relief and the valley lines were detected as the segmentation lines. Considering the boundary pixels of the distance map as water heads, the water will flow forward. They will turn when facing a slope and will go on when facing a valley mouth according to the terrain of the valley. This results in the segmentation. This method will take no influence on single kernels, so does not need a touching estimate by manual input threshold before segmentation. An experiment to 442 connected components of single kernels and multi-touching kernels shows an accuracy of 99.7% for touching estimation and 94.9% for touching kernels segmentation. Number of references:22 Main heading:Image segmentation Controlled terms:Binary images - Estimation - Facings - Landforms - Mathematical morphology - Watersheds Uncontrolled terms:Connected component - Euclidean distance - Maize kernels - Region growing - Segmentation lines - Segmentation methods - Touching - Touching kernels Classification code:402 Buildings and Towers - 444.1 Surface Water - 481.1 Geology - 723.2 Data Processing and Image Processing - 921 Mathematics DOI:10.6041/j.issn.1000-1298.2014.09.046 Database:Compendex 38. Accession number:201442113329 Title:Control and analysis software design of hyperspectral imaging system for detection in agricultural food quality Authors:Zhao, Juan1 ; Peng, Yankun1 ; Guo, Hui1, 2 ; Tao, Feifei1 ; Zhang, Leilei1 Author affiliation:1 National Research and Development Center for Agro-processing Equipment, China Agricultural University, Beijing, China 2 College of Mechanical and Traffic, Xinjiang Agricultural University, Urumqi, China Corresponding author:Peng, Yankun Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:210-215 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Hyperspectral imaging technology was applied for quality detection of agricultural product. The research was based on laboratory setup and application. A software system was developed for real-time, rapid detection of agricultural product based on hyperspectral imaging technology. A real-time hardware system consisted of sample feeding unit, on-line detection unit and sample separation unit. The important on-line detection unit comprised charged couple device (CCD) camera, imaging spectrometer, lens, data acquisition card, light source. Sensor was developed to acquire image of intact samples. Control and analysis software was designed to detect quality parameter in agricultural food based on the VS2010 and Matlab platforms. The software designed included instrument parameter setting module, signal detection and control module and data collection and analysis module. Each functional module was divided into several sub function modules according to different function. These three main modules were integrated together to achieve the software functions of images acquisition, images synthesis, motion control, data extraction, storage and display. For data analysis, the study emphased on analyzing the process of image synthesis in the interface of image display step by step. At the same time, for efficient image processing and spectral information in the software system, image data correction and choice of region of interest is required to display and calculate data in the whole software. Because of hyperspectral imaging technique included image information and spectral information, two part information for detecting samples was represented different preprocessing analysis method to eliminate noise and correct the original information. This study makes use of all above mentioned hardware and method to design practical analysis software to detect a variety of quality parameters of meet. It describes design ideas of the meet detection flowchart and shows the graphical user interface (GUI). The result stated that this method is effective and practical to design an integrated control analysis software for a real-time system based on hyperspectral imaging technology. Number of references:16 Main heading:Quality control Controlled terms:Agricultural products - Agriculture - Computer control - Computer software - Data acquisition - Digital storage - Graphical user interfaces - Hardware - Image processing - Imaging techniques - Light sources - MATLAB - Real time systems - Social networking (online) - Software design - Spectroscopy Uncontrolled terms:Agricultural foods - Analysis softwares - Charged couple device cameras - Graphical user interfaces (GUI) - Hyperspectral imaging systems - Hyperspectral imaging techniques - Hyperspectral imaging technologies - Quality detection Classification code:605 Small Tools and Hardware - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 744 Lasers - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 913.3 Quality Assurance and Control - 921 Mathematics DOI:10.6041/j.issn.1000-1298.2014.09.034 Database:Compendex 39. Accession number:201442113303 Title:Current situation of navigation technologies for agricultural machinery Authors:Ji, Changying1 ; Zhou, Jun1 Author affiliation:1 College of Engineering, Nanjing Agricultural University, Nanjing, China Corresponding author:Ji, Changying Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:44-54 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Navigation is a key technology for agriculture machinery when it works automatically, and it becomes a hotspot in research field of agricultural machinery at present. In this paper, literatures are reviewed according to the main ways and key technologies of navigation of agricultural machinery. First of all, navigation technologies based on global positioning system and machine vision were reviewed in detail. Then other ways such as electromagnetic navigation, mechanical navigation, laser navigation, ultrasonic navigation, geomagnetic navigation were reviewed briefly. Sensing of environment, control methods and mapping of environment as the key technologies of the navigation were introduced respectively. Finally, the future development of navigation technologies for agricultural machinery was analyzed. Number of references:81 Main heading:Agricultural machinery Controlled terms:Agriculture - Computer vision - Geomagnetism - Navigation - Reviews Uncontrolled terms:Agriculture machinery - Control methods - Current situation - Geomagnetic navigation - Key technologies - Laser navigations - Navigation technology - Research fields Classification code:481.3.2 Earth Magnetism and Terrestrial Electricity - 716.3 Radio Systems and Equipment - 723.5 Computer Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 903.2 Information Dissemination DOI:10.6041/j.issn.1000-1298.2014.09.008 Database:Compendex 40. Accession number:201442113317 Title:Experimental and numerical investigations of cavitation in a centrifugal pump with pre-whirl regulation Authors:Zhang, Yongxue1 ; Song, Pengfei1 ; Xu, Cong1 ; Tian, Yuan1 ; Zhang, Jinya1 Author affiliation:1 College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing, China Corresponding author:Zhang, Yongxue Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:131-137 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:With the aim to explore the influence of inlet guide vane on the cavitation performance of centrifugal pump, the cavitation experiment on IS 150-125-250 centrifugal pumps with original design inlet guide vane has been conducted. Using the Zwart-Gerber-Belamri cavitation model, the 3D unsteady cavitation flow in centrifugal pump flow channels has been simulated. The result shows that the negative pre-whirl by guide vane regulation could improve the cavitation performance of centrifugal pump in a certain angle range, and the cavitation performance was deteriorated when the angle exceeds the certain value. The positive pre-whirl regulation deteriorated the cavitation performance of centrifugal pump, and it become even more serious with the increasing positive pre-whirl angle. The analysis of the vapor volume fraction distribution in impeller channels indicates that the negative pre-whirl angle reduced the cavitation zones in impeller, and the positive pre-whirl angle expanded the cavitation zones in impeller channels. Number of references:12 Main heading:Cavitation Controlled terms:Centrifugal pumps - Computer simulation - Experiments - Impellers - Pumps - Wakes Uncontrolled terms:Cavitation model - Cavitation performance - Impeller channels - Inlet guide vane - Numerical investigations - Pre-whirl regulation - Unsteady cavitation - Vapor volume fraction Classification code:601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 723.5 Computer Applications - 901.3 Engineering Research DOI:10.6041/j.issn.1000-1298.2014.09.022 Database:Compendex 41. Accession number:201442112893 Title:Topology optimization of continuum structures using node variable method Authors:Zhan, Jinqing1 ; Yang, Kang1 ; Huang, Zhichao1 Author affiliation:1 School of Mechanical and Electrical Engineering, East China Jiaotong University, Nanchang, China Corresponding author:Zhan, Jinqing Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:329-332 and 339 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A topology optimization design of continuum structures using node variable method was proposed not only to avoid the phenomenon of numerical instabilities but also to consider the manufacturing requirements. Within the defined sub-domain, the projection function independent on element mesh was adopted to represent the relationship of node design variables and node density variables. It could achieve the minimum length scale constraint of the topological solution to meet processing requirements. With the objective function developed by the minimum strain energy to meet stiffness requirement, and the volume used as the constraints, the topology optimization model of continuum structure under minimum length scale constraints was developed. The method of moving asymptotes was adopted to solve the topology optimization problem. The numerical examples indicated that the approach could avoid the phenomenon of numerical instabilities and obtain distinct topological structure which is convenient for manufacturing. Number of references:15 Main heading:Topology Controlled terms:Manufacture - Numerical methods - Optimization - Shape optimization - Structural design - Structural optimization Uncontrolled terms:Continuum structures - Method of moving asymptotes - Node designs - Node variable method - Numerical instability - Objective functions - Projection function - Topological structure Classification code:408.1 Structural Design, General - 537.1 Heat Treatment Processes - 921 Mathematics DOI:10.6041/j.issn.1000-1298.2014.09.053 Database:Compendex 42. Accession number:201442113321 Title:Anti-clogging design and experimental investigation of PIV for labyrinth-channel emitters of drip irrigation emitters Authors:Yu, Liming1, 2 ; Mei, Qiyong1, 2 Author affiliation:1 School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, China 2 Key Laboratory of Water-sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha University of Science & Technology, Changsha, China Corresponding author:Yu, Liming Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:155-160 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:In order to improve the reference of designing of anti-clogging ability of labyrinth channel emitter, the sand content and water and sand velocity distribution in the trapezoidal labyrinth channels were analyzed by CFD, the movement trajectories and velocity of solid particles in modified channel before and after tested by PIV. The phenomenon of a large number of solid particles concentrated on the surface near the upstream face and low velocity position of trapezoidal-channel emitters. When flow path is being modified, it is appropriate to increase the modification of the upstream face. Combined with the whole flow path and processing requirements, the downstream face may need not modified. Regarded the some one sand content distribution line as the borderlines of trapezoidal-channel to design the channel several times, after structural standardization and selecting the wide flow path, the position with high sand content can be canceled, and the better channel model is got. The method tested by CFD and PIV can keep the previous hydraulic performance before modification, and significantly improve the anti-clogging performance. Number of references:19 Main heading:Computational fluid dynamics Controlled terms:Design - Irrigation - Rivers - Sand - Velocity distribution Uncontrolled terms:Anti-clogging - Configuration designs - Emitter - PIV - Trapezoidal-channel Classification code:407.2 Waterways - 408 Structural Design - 505 Mines and Mining, Nonmetallic - 821.3 Agricultural Methods - 921.6 Numerical Methods - 943.2 Mechanical Variables Measurements DOI:10.6041/j.issn.1000-1298.2014.09.026 Database:Compendex 43. Accession number:201442113297 Title:Control model and time response of magnetorheological speed regulating start technology Authors:Wang, Daoming1 ; Hou, Youfu2 ; Tian, Zuzhi2 ; Meng, Qingrui2 Author affiliation:1 School of Mechanical and Automotive Engineering, Hefei University of Technology, Hefei, China 2 School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, China Corresponding author:Wang, Daoming Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:8-13 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:With the aim to reveal the characteristics and influence factors of time response for the magnetorheological (MR) speed regulating start process, the basic component and working principle of the MR speed regulating start control system were analyzed at first. Then, the mathematical control model of output speed was established in combination with the basic laws of magnetic circuit, constitutive model of MR fluids as well as systematic dynamics equations. Moreover, time response of MR speed regulating start under various excitation currents, input speed and load torques was simulated and analyzed by using the Matlab/Simulink software. And subsequently, several speed regulating start experiments were carried out under different initial conditions. Both the simulation and experimental results concerning the response time of the output speed are presented and discussed in detail. Research results indicate that the response time of MR speed regulating start increases with the decrease of the excitation current and the increase of the load torque, while it exhibits an approximate proportional relationship with the input speed; the influence laws of various factors on time response are basically the same between experiments and simulations, which in return proves the validity of theoretical model and simulation analysis. However, simulation values are relatively smaller for about 0.36 s in compassion with experimental results for not considering the magnetic response of the circuit and the rheological response of the MR fluids. Research results may serve to provide a theoretical reference and experimental basis for the development and practical application of the MR speed control technology. Number of references:15 Main heading:Speed Controlled terms:Magnetorheological fluids - Speed control - Torque measurement - Yield stress Uncontrolled terms:Control technologies - Excitation currents - Matlab/Simulink software - Proportional relationships - Rheological response - Speed-regulating - Theoretical modeling - Time response Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 708.4 Magnetic Materials - 731.3 Specific Variables Control - 931.1 Mechanics - 943.2 Mechanical Variables Measurements - 951 Materials Science DOI:10.6041/j.issn.1000-1298.2014.09.002 Database:Compendex 44. Accession number:201442113332 Title:Identification of expanded kiwifruits by near-infrared diffused spectroscopy Authors:Guo, Wenchuan1 ; Liu, Dayang1 Author affiliation:1 College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; Shaanxi, China Corresponding author:Guo, Wenchuan Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:230-235 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:In order to develop a nondestructive method for identifying expanded kiwifruits, near-infrared diffused spectra of 120 expanded kiwifruits and 120 normal kiwifruits were obtained between 833 and 2500 nm using a Fourier transformation near-infrared diffused spectrograph. Standard normal variate transformation was used to preprocess original spectra. The samples were divided into calibrationset and prediction set based on Kennard-Stone method. Eleven principal components and 6 characteristic wavelengths were selected by principal component analysis (PCA) and successive projections algorithm (SPA). Partial least squares (PLS), support vector machine (SVM), and error back propagation (BP) neural network identification model were established based on full spectrum (FS), PCA, and SPA, respectively. The results showed that correct identification rates of all models were higher than 96.7% and 93.3% for calibration set and predication set, respectively. The established models based on PCA and SPA were much simpler than those based on FS, since the variable numbers of them were only about 0.53% and 0.29% of that of FS, respectively. The identification performance of PLS and SVM were better than that of BP. The best model was PCA-PLS, whose accuracy rate reached 100% for calibration set and predication set. The results clearly indicate that near-infrared diffused spectra technique has the potential as an efficient, accuracy and non-invasive method for distinguishing expanded kiwifruits from normal kiwifruits. Number of references:19 Main heading:Principal component analysis Controlled terms:Backpropagation - Calibration - Fourier transforms - Identification (control systems) - Infrared devices - Least squares approximations - Noninvasive medical procedures - Support vector machines Uncontrolled terms:Error back propagation - Fourier transformations - Kiwifruits - Near infrared spectra - Nondestructive methods - Partial least square (PLS) - Standard normal variate transformations - Successive projections algorithms (SPA) Classification code:461.6 Medicine and Pharmacology - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 731.1 Control Systems - 741.3 Optical Devices and Systems - 921.3 Mathematical Transformations - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments DOI:10.6041/j.issn.1000-1298.2014.09.037 Database:Compendex 45. Accession number:201442113336 Title:Leaves and stems measurement of plants based on laser vision in greenhouses Authors:Zhang, Yu1 ; Wang, Xiaochan1 ; Sun, Guoxiang2 ; Li, Yongbo2 ; Sun, Xin1 Author affiliation:1 College of Engineering, Nanjing Agricultural University, Nanjing, China 2 Jiangsu Province Engineering Lab. for Modern Facilities Agricultural Technology and Equipment, Nanjing, China Corresponding author:Wang, Xiaochan Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:254-259 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A laser vision-based measurement system consisting of a camera and a laser sheet that scanned the plant vertically was developed to measure the stem diameters and leaf lengths automatically. The 3D point cloud was obtained with the laser sheet scanning the plant vertically, while the camera videoed the process of laser scanning. Laser line centers were extracted by improved centroid method. The 3D point cloud structure of the sample plant was obtained. For leaf length measurement, iteration method for point clouds was used to extract the axis of the leaf point cloud set. The centroid of the subset of points was calculated and taken as the next axis point. Leaf length was calculated by curve fitting on these axis points. In order to increase the accuracy of curve fitting, bi-directional starting point selection was used. To evaluate the method in a sample of 8 water spinaches, the lengths of leaves and diameters of stems were measured manually and plotted versus their automatically measured counterparts. The accuracy of leaf lengths and stem diameters are 95.39% and 94.55% respectively. The tests proved that laser vision-based method could be used on plant geometries measurement in greenhouses costly and portably. Number of references:25 Main heading:Plants (botany) Controlled terms:Cameras - Curve fitting - Greenhouses - Iterative methods Uncontrolled terms:3D point cloud - Iteration method - Laser vision - Leaf and stem of plant - Morphological parameters - Point selection - Vision-based measurements - Vision-based methods Classification code:402.1 Industrial and Agricultural Buildings - 461.9 Biology - 742.2 Photographic Equipment - 921.6 Numerical Methods DOI:10.6041/j.issn.1000-1298.2014.09.041 Database:Compendex 46. Accession number:201442113301 Title:Test method research on vehicle's tire side slip angle in extreme driving conditions Authors:Zhang, Xiaolong1 ; Chen, Bin1 ; Song, Jian2 ; Wang, Qiyong1 Author affiliation:1 School of Engineering, Anhui Agricultural University, Hefei, China 2 State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing, China Corresponding author:Song, Jian Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:31-36 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Identification of tire cornering properties is the base of vehicle dynamics stability control, however, tire side slip angle estimation accuracy based on dynamic model goes worse because of the effects of roll steering and compliance steer under the extreme driving conditions. In order to provide technical means for research on steering wheel angle and wheel side slip angle observation model under the extreme conditions, this paper presents a test method for tire side slip angle based on the direct vision measurement of steering wheel angle and the vehicle body attitude. The test principle of the side slip angle was firstly analyzed, then the roadway test system was established based on the high-precision, double antenna differential GPS and the real-time image processing device CVS 1456. On the basis of the calibration of the test vehicle steering system gear ratio, both the pivot steering test and the small lateral acceleration test showed the good consistency of the results of the steering wheel angle based on image acquisition with the hand-wheel angle. In addition, the circular acceleration-deceleration tests showed that the test vehicle reached the extreme conditions while the lateral acceleration was more than 0.8 g, and at this time the steering wheel angle curve with image acquisition method fluctuates and reflects the effects of roll steering and compliance steer, so comprehensively the test vehicle has understeer characteristics. The roadway tests indicate that the method proposed is effective and practicable. Number of references:15 Main heading:Testing Controlled terms:Automobile steering equipment - Compliance control - Image acquisition - Image processing - Steering - Tires - Vehicle wheels - Vehicles - Wheels Uncontrolled terms:Driving conditions - Extreme conditions - Lateral acceleration - Motor vehicle - Real-time image processing - Sideslip angles - Test method - Vision measurement Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 432 Highway Transportation - 601.2 Machine Components - 663.2 Heavy Duty Motor Vehicle Components - 723 Computer Software, Data Handling and Applications - 731.3 Specific Variables Control - 741 Light, Optics and Optical Devices - 818.5 Rubber Products DOI:10.6041/j.issn.1000-1298.2014.09.006 Database:Compendex 47. Accession number:201442113326 Title:Effect of different pretreatment methods on sewage sludge anaerobic digestion Authors:Zhang, Wanqin1 ; Qi, Dandan1 ; Wu, Shubiao2 ; Dong, Renjie2 ; Zhao, Wansheng3 Author affiliation:1 College of Agronomy and Biotechnology, China Agricultural University, Beijing, China 2 College of Engineering, China Agricultural University, Beijing, China 3 Beijing Jun De Construction Engineering Co. Ltd., Beijing, China Corresponding author:Wu, Shubiao Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:187-198 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:With the widely use of biological wastewater treatment, a large number of sewage sludge (SS) was produced in the process. The treatment of SS has become a major challenge for wastewater treatment plants. Landfill and incineration as traditional methods of sludge treatment not only pollute the environment but also consume a lot of energy. Anaerobic digestion as a sustainable sludge treatment method benefits environmental protection and energy saving. However, traditional anaerobic digestion of sludge treatment has the characters of low efficiency, poor biodegradability and long residence time. Therefore, in order to improve the efficiency of anaerobic digestion of SS, the pretreatments are paid more and more attention. According to the physical and chemical properties and the anaerobic digestion of sludge characteristics, this study assessments the different mechanisms of various sludge pretreatment methods. Simultaneously, different types of sludge pretreatment were classified. And the effects of different types of sludge pretreatment on the characteristics of anaerobic digestion of sludge were compared further. Moreover, the influence factors of different sludge anaerobic digestion treatment were evaluated deeply. Besides, the problems of anaerobic sludge digestion and the direction for the future development of anaerobic sludge digestion were briefly analyzed. Number of references:83 Main heading:Sludge digestion Controlled terms:Anaerobic digestion - Biodegradation - Biological sewage treatment - Biological water treatment - Incineration - Sewage sludge - Waste incineration - Wastewater treatment Uncontrolled terms:Anaerobic sludge digestion - Biological waste water treatment - Physical and chemical properties - Pre-Treatment - Pretreatment methods - Sludge - Sludge characteristics - Wastewater treatment plants Classification code:445.1 Water Treatment Techniques - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 801.2 Biochemistry DOI:10.6041/j.issn.1000-1298.2014.09.031 Database:Compendex 48. Accession number:201442113304 Title:Navigation of an agricultural robot based on laser radar Authors:Xue, Jinlin1 ; Zhang, Shunshun1 Author affiliation:1 College of Engineering, Nanjing Agricultural University, Nanjing, China Corresponding author:Xue, Jinlin Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:55-60 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The navigation performance was studied for an agricultural robot based on laser radar between the crop rows with intra-row spacing and without intra-row spacing, especially in the absence of one-side crop row. According to the crop information from the laser radar, the different navigation methods were developed to calculate navigation path and thus to determine the lateral error and heading angle error for the different type of the crop rows. Then the fuzzy logic control was used to control the robot to travel along the calculated navigation path. Tests were conducted in three replications respectively while the robot traveled between the evergreen tree rows with a missing distance of 4 m in one side and the pear tree rows with a missing distance of 6.2 m in one side. Results showed that, the robot traveled successfully, with the maximum navigation errors of 17.5 cm and 28 cm for the evergreen tree tests and the pear tree tests respectively, when the inter-row spacing of the evergreen trees and the pear trees were not fixed in the respective test distance. Meanwhile, the missing distance in one side for the evergreen trees had no significant effect on the traveling of the robot, but it seemed to have an effect for the missing distance of the pear trees. According to the statistic data of the tests and the robot trajectories, it was shown that the control algorithm had ability to make the robot travel along the centerline of the crop rows. Number of references:15 Main heading:Robots Controlled terms:Agriculture - Algorithms - Crops - Forestry - Fruits - Fuzzy logic - Navigation - Optical radar - Radar Uncontrolled terms:Agricultural robot - Evergreen trees - Fuzzy logic control - Navigation error - Navigation methods - Navigation paths - Navigation performance - Robot trajectory Classification code:716.2 Radar Systems and Equipment - 716.3 Radio Systems and Equipment - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723 Computer Software, Data Handling and Applications - 731.5 Robotics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics DOI:10.6041/j.issn.1000-1298.2014.09.009 Database:Compendex 49. Accession number:201442113308 Title:Study of rapid and automatic non-destructive testing grader for red jujubes Authors:Wang, Songlei1, 2 ; Liu, Minfa1 ; He, Jianguo1, 2 ; He, Xiaoguang1 ; Wu, Longguo1 Author affiliation:1 Department of Agriculture, Ningxia University, Yinchuan, China 2 Department of Civil Engineering and Water Conservancy, Ningxia University, Yinchuan, China Corresponding author:He, Jianguo Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:79-83 and 95 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:An automated rapid non-destructive testing grader based on machine vision technology for jujubes was designed, which can discriminate and grade jujubes according to their external indicators. The equipment is mainly composed of five parts: monomeric orientation arrangement conveying system, multi-surface image acquisition and processing system, grading actuators, transmission mechanism and control system. Rapid monomeric arrangement delivery of jujubes was achieved by roller conveyor and cam intermittent motion mechanism, multi-surface images of jujubes were obtained by industrial camera, front and back light and STM32 system. In addition, pneumatic grading actuator was designed to grade jujubes. The performance parameters were determined by calculating and testing, which were conveyor angle 28°, running speed 160 mm/s, monomer orientation arrangement rate 95%, grading speed 10 jujubes/s, accuracy 92%, the maximum production capacity 550 kg/h. The requirement of automated rapid detection and grading can be reached well by the grader. Number of references:17 Main heading:Grading Controlled terms:Actuators - Automation - Computer vision - Conveyors - Design - Nondestructive examination - Pneumatic actuators Uncontrolled terms:Automated grader - Intermittent motion mechanism - Non destructive testing - Performance parameters - Production capacity - Rapid non-destructive testing - Red jujubes - Transmission mechanisms Classification code:408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 692.1 Conveyors - 731 Automatic Control Principles and Applications - 731.6 Robot Applications - 732 Control Devices - 732.1 Control Equipment - 913.3 Quality Assurance and Control DOI:10.6041/j.issn.1000-1298.2014.09.013 Database:Compendex 50. Accession number:201442113324 Title:Comparison of soil hydraulic properties under different land use pattern Authors:She, Dongli1 ; Liu, Yingying1 ; Yu, Shuang'en1 ; Gao, Xuemei1 ; Zheng, Jiaxing1 Author affiliation:1 Key Lab. of Efficient Irrigation-Drainage and Agricultural Soil-Water Environ. in Southern China, Ministry of Education, Hohai University, Nanjing, China Corresponding author:She, Dongli Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:175-179 and 186 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Based on the infiltration experiments using two size-disc infiltrometers, the characteristics of the soil hydraulic properties at four different pressure heads (-9, -6, -3, and 0 cm) were analyzed under four land uses. The results showed that the infiltration rates were not obviously different tested by infiltrometers with different diameter discs. The infiltrometer with small disc was more suitable for the field determination of soil hydraulic properties. With the decreasing of the pressure head, steady infiltration rates of the 4 soils decreased to different extents. Soil hydraulic conductivity and Gardner α were determined according to the experimental data at different negative water pressure heads, which were obviously different with land uses. Land use had significant effects on the contributions of macropores and micropores to flow. The contribution of each class pore to flow was reduced with the decrease of the pore size under tea garden and grass land. However, the contributions of micropores (<0.1 mm) to flow were kept the highest level in vegetable field and protected field. The result could provide references for estimating hydraulic parameters of soils in hilly area of South China. Number of references:22 Main heading:Infiltration Controlled terms:Land use - Microporosity - Soils Uncontrolled terms:Disc infiltrometer - Field determination - Hydraulic parameters - Land use pattern - Soil hydraulic conductivity - Soil hydraulic properties - Steady infiltration rate - Water pressures Classification code:403 Urban and Regional Planning and Development - 483.1 Soils and Soil Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids DOI:10.6041/j.issn.1000-1298.2014.09.029 Database:Compendex 51. Accession number:201442113320 Title:Spatial variability of total soil nitrogen content in karst area of southwest China Authors:Li, Wenjun1 ; Yang, Qiyong2 ; Peng, Baofa1 ; Zhao, Di1 Author affiliation:1 College of Resources and Environment and Tourism, Hunan University of Arts and Science, Changde, China 2 Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, China Corresponding author:Yang, Qiyong Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:150-154 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A typical peak-cluster depression area was selected as the study area. Based on the relationships between total soil nitrogen content in 0~20 cm depth and terrain attributes by multiple linear stepwise regression method, the spatial variability of total nitrogen was studied by ordinary Kriging (OK), univariate Cokriging (COK) and multivariable Cokriging (MCOK) methods. Results showed that the spatial distribution of total nitrogen can be described by two regression models. Distance from ridge of mountains (VDFR) entered into the regression equation for the model (1), and distance from ridge of mountains (VDFR) and relief degree of land surface (VRS) entered into the regression equation for the model (2). Therefore, VDFR was selected as auxiliary variable to predict total nitrogen by COK method, and VDFR and VRS were selected as auxiliary variables to predict total nitrogen by MCOK method. The Kriging interpolation indicated that when the correlation coefficient between total nitrogen and terrain attributes was small, the accuracy of COK was increased litter. While MCOK can promote the accuracy notable. This study can provide a new idea and method for evaluation and ecological reconstruction of the karst rock desertification. Number of references:17 Main heading:Nitrogen Controlled terms:Forestry - Geomorphology - Interpolation - Landforms - Regression analysis - Soils Uncontrolled terms:Co-Kriging - Correlation coefficient - Ecological reconstruction - Kriging interpolation - Semi-variances - Soil nitrogen content - Southwest China - Stepwise regression method Classification code:481.1 Geology - 481.1.1 Geomorphology - 483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 821.0 Woodlands and Forestry - 921.6 Numerical Methods - 922.2 Mathematical Statistics DOI:10.6041/j.issn.1000-1298.2014.09.025 Database:Compendex 52. Accession number:201442113310 Title:Numerical investigation of compessible flow in a three-stage helico-axial multiphase pump Authors:Zhang, Jinya1 ; Cai, Shujie1 ; Zhu, Hongwu1 ; Yang, Ke1 ; Qiang, Rui1 Author affiliation:1 College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing, China Corresponding author:Zhang, Jinya Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:89-95 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Numerical simulations were conducted on a three-stage helico-axial multiphase pump under different conditions of gas volume fraction (GVF). Water was chosen as the first phase and ideal air was the second phase. k-ω SST turbulence model and dispersed phase zero equation model were selected to simulate the liquid-gas two-phase steady and unsteady flow. The hydraulic performance of the pump according to the simulations was well coincident with the experimental results. The results show that GVF and total volume flow declined smoothly from the first stage to the third for the compressiblity of gas. Due to different centrifugal forces on the two phases, the gas was distributed mainly around the hub; with the increase of GVF, the differential pressure of the first stage decreased slowly while the second and third stagesincreased at first and then decreased. When the inlet GVF was less than 10% or more than 80%, the differential pressure among the three stages were close, so the design and simulation in these conditions could regard as the imcompressible fluid. But in other conditions, it was necessary to consider the fluid as the compressible one; because of the stator-rotor interference and limited number of blades, the average pressure decreased at the interface between impeller and diffuser. Number of references:17 Main heading:Compressibility of gases Controlled terms:Compressible flow - Computer simulation - Flowmeters - Gases - Interference suppression - Numerical models - Pumps - Turbulence models - Volume fraction Uncontrolled terms:Design and simulation - Differential pressures - Gas volume fraction - Helico-axial multiphase pump - Hydraulic performance - Imcompressible fluids - Numerical investigations - SST turbulence models Classification code:443.1 Atmospheric Properties - 618.2 Pumps - 631.1.1 Liquid Dynamics - 641.1 Thermodynamics - 711 Electromagnetic Waves - 723.5 Computer Applications - 921 Mathematics - 931.2 Physical Properties of Gases, Liquids and Solids - 943.1 Mechanical Instruments DOI:10.6041/j.issn.1000-1298.2014.09.015 Database:Compendex 53. Accession number:201442113316 Title:Energy loss analysis of impeller flow of screw centrifugal pump Authors:Li, Rennian1 ; Shen, Zhengjing1 ; Han, Wei1 ; Quan, Hui1 ; Li, Qifei1 Author affiliation:1 School of Energy and Power Engineering, Lanzhou University of Technology, 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:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:125-130 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:The flow regime in screw centrifugal pump was simulated by the method of computational fluid dynamics (CFD), which can acquire the distribution of the pressure and relative velocity on the work side and back side of blade. The Rothalpy value along the streamlines of blade was used as a quantitative index of energy loss. The energy loss within the impeller field was analyzed from the perspective of energy loss when the transmission medium is pure water and solid-liquid two phase flow, in which the concentration of sand is 20% and the diameter of sand is 0.076 mm. The result shows that the front of impeller is a transition region of energy conversion, the screw part is the main region of energy increase, and the friction loss at the middle of screw part has an effect on the working capacity of screw part. Compared with pure water transmission medium, the working capacity of the impeller shows some improvement when the transmission medium is the solid-liquid two phase flow. And the energy of the two kind transmission media tends to become average at the outlet of impeller. Number of references:11 Main heading:Two phase flow Controlled terms:Centrifugal pumps - Computational fluid dynamics - Energy dissipation - Impellers - Liquids - Pumps - Screws Uncontrolled terms:Energy loss analysis - Quantitative indices - Relative velocity - Screw centrifugal pumps - Solid-liquid two phase flows - Transition regions - Transmission media - Transmission medium Classification code:525.4 Energy Losses (industrial and residential) - 601.2 Machine Components - 605 Small Tools and Hardware - 618.2 Pumps - 631 Fluid Flow - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids DOI:10.6041/j.issn.1000-1298.2014.09.021 Database:Compendex 54. Accession number:201442113313 Title:3D dynamic characteristics of rotor system of pump storage generator set Authors:Zhai, Liming1 ; Yao, Ze2 ; Huang, Qingsong2 ; Yan, Zongguo3 ; Wang, Zhengwei1 Author affiliation:1 State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing, China 2 Electric Power Research Institute of Guangdong Power Grid Corporation, Guangzhou, China 3 China Power Complete Equipment Co. Ltd., Beijing, China Corresponding author:Wang, Zhengwei Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:107-111 and 137 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:Analysis on shaft critical speed of pumped storage generator set is a complex problem in rotor dynamics under the influences of mechanical, electromagnetic and hydraulic factors. A 3D finite element model of a rotor-bearing-electromagnetic coupled system for pumped storage generator set was built in SAMCEF ROTOR. The stiffness coefficients of unbalanced magnetic pull, the shaft critical speeds and the modes of vibration were calculated. The effects of the stiffness change of unbalanced magnetic pull in generator, turbine guide bearing and generator guide bearings on the critical speed were also discussed. The results show that the unbalanced magnetic pull increases nonlinearly as the excitation current and rotor eccentricity increase, and decreases the first order lateral critical speed. The lateral critical speed increases with the stiffness of the guide bearings, among which the turbine guide bearing mainly affects the second order critical speed, while the upper and lower generator guide bearing mainly influence the first and third critical speeds. Number of references:17 Main heading:Rotors (windings) Controlled terms:Bearings (structural) - Electric generators - Electric machine theory - Finite element method - Hydraulic motors - Hydroelectric generators - Magnetic storage - Speed - Stiffness - Turbines Uncontrolled terms:3D finite element model - Critical speed - Dynamic characteristics - Excitation currents - Lateral critical speed - Rotor eccentricity - Stiffness coefficients - Unbalanced magnetic pull Classification code:408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 612.3 Gas Turbines and Engines - 632.2 Hydraulic Equipment and Machinery - 704.1 Electric Components - 705.1 Electric Machinery, General - 705.2 Electric Generators - 708.4 Magnetic Materials - 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science DOI:10.6041/j.issn.1000-1298.2014.09.018 Database:Compendex 55. Accession number:201442113345 Title:Analysis on dynamics characteristic of heavy-load parallel motion simulation platform mechanism Authors:Yuan, Feihu1 ; Zhao, Tieshi1 ; Bian, Hui2 ; Liu, Xiao2 Author affiliation:1 Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University, Qinhuangdao, China 2 Key Laboratory of Advanced Forging & Stamping Technology and Science, Ministry of Education of China, Yanshan University, Qinhuangdao, China Corresponding author:Zhao, Tieshi Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery Abbreviated source title:Nongye Jixie Xuebao Volume:45 Issue:9 Issue date:September 25, 2014 Publication year:2014 Pages:311-317 Language:Chinese ISSN:10001298 CODEN:NUYCA3 Document type:Journal article (JA) Publisher:Chinese Society of Agricultural Machinery Abstract:A 6UPS-3UPS/UPU-R parallel motion simulation platform mechanism with the capacity to carry heavy load was presented. Driven by electro-hydraulic hybrid, the mechanism could compensate the gravity of the load. Calculation formulas of the force acting on moving platform exerted by the balance platform and the motor torque were obtained by analyzing the dynamics of the mechanism. The balance efficiency was presented, and then the influence of relevant parameters of the balance branches on balance efficiency was researched. The effects of hydraulic cylinders on the force of moving platform and the drive of electric cylinders were got. The numerical analysis indicates that the balance hydraulic cylinder can decrease the motor torque effectively, and the parallel motion simulation platform mechanism can satisfy the application requirements of high precision and heavy load with low manufacturing cost. Number of references:15 Main heading:Loads (forces) Controlled terms:Cylinders (shapes) - Dynamics - Mechanical actuators Uncontrolled terms:Application requirements - Balance platforms - Calculation formula - Electro-hydraulic hybrid - Heavy-load - Hydraulic cylinders - Manufacturing cost - Parallel motion Classification code:408 Structural Design - 408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 732.1 Control Equipment - 931.1 Mechanics DOI:10.6041/j.issn.1000-1298.2014.09.050 Database:Compendex
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