Abstract:Maize can be used as food, animal feed and industrial raw material. The increase in maize yield is of great value to support growing population in the world. At present, it is widely planted around the world, and maize planters are generally adopted in the seeding process. Because cultivatable field is limited, increasing the yield per area is the only way to increase the whole yield. Precision seeding is an effective method to increase the yield. However, the precision that mechanization contributes to the seeding has been maximized. In order to further improve the seeding precision, intelligent technology has gradually been used on maize planters. For domestic planters, it is relatively high on the mechanization level, but it is low on the intelligent level. Maize planters play important role in the seeding process, however, people still have to play a part in monitoring the state of planters. It is not only laborintensive, but also lacking of precision. Therefore, intelligent technologies must be fully used to replace the human labor. The seeding process can be classified into metering process, transporting process and landing process. From this perspective, the working principle, technical feature and developing situation of seeding technology and its measurement and control technology applied to maize planters were described. On the basics of analyzing and generalizing all advantages and disadvantages of seeding technology, the developing trends of seeding technologies were prospected, and the new demands about maize seeding technologies in the background of precision agriculture were predicted.

Abstract:Path planning with distance and time constraints is often required for mobile robots. Meanwhile, reducing energy consumption is much more important in order to make robot perform more tasks and more efficiently with limit energy supply. Hence, it is important to minimize the energy consumption of mobile robots deployed in real world missions. One of the ways that can be accomplished is to choose the robot’s motion to minimize the mechanical and electrical energy usage required by the robot’s motion. However, this method will cause the robot accelerate or decelerate frequently. Taking into account the demand for reducing energy consumption and improving the efficiency of path planning, an energy optimal path planning method was proposed based on AD* algorithm. The energy consumption was reduced with the proposed energy optimal path planning method by taking into account the distance and time constraints. Firstly, the energy consumption of path was calculated by using the dynamic model and power model of the robot. The samplebased model predictive optimization algorithm was used to generate the optimal trajectory cluster based on the kinematics model of robot. Then, an energy optimal path planning method was proposed based on AD* search algorithm by integrating the energy consumption into the node’s evaluation function. Energy optimal path planning was carried out online to find the optimal energy consumption path, according to the connection relationship of nodes and environment map. Finally, the effectiveness of the proposed energy optimal path plannign method was confirmed by comparing the simulation results with distance optimal path planning method. The proposed energy optimal path planning method can be deployed on the mobile robot platform which served in outdoor terrain environments for decreasing energy consumption.

Abstract:Phenotype-based classification plays an essential role in plant research. Chrysanthemum flower has great momentous economic value and medicinal value, and has feature of morphological and genetic diversity as well. Due to the limitations of the artificial classification model by expert and the characteristic of genetic diversity, phenotype-based classification has been facing great challenges for its research. At present, the technologies and applications of machine learning and artificial intelligence are developing rapidly. With the vehicle of machine learning, the semi-supervised learning technology was employed to provide an effective way for improving the classification performance. This method was based on label propagation of graph model as well as active learning technique. According to this method, a small number of classified chrysanthemum data as well as a large amount of unlabeled chrysanthemum samples were exploited to improve the classification accuracy. This method can automatically make use of the unlabeled samples to improve the quality of chrysanthemum classification without relying on external interactions. The chrysanthemum phenotypic data was collected to train the learning model, and manually annotate the chrysanthemum category information. For exploiting the categorical attribute, the coding skill was studied as well. The label propagation of graph model was utilized by the semi-supervised learning skill for the unlabeled chrysanthemums. In order to improve the effectiveness of semi-supervised classification, active learning technique was applied, which was based on the entropy maximization strategy to select difficult-to-identify samples to improve classification performance further. Extensive experiments were conducted and comparisons were made. The experimental results showed that the unlabeled chrysanthemum samples can improve the classification accuracy remarkably, with the labeled ratio increasing from 6.25% to 23%, the recognition accuracy rapidly reached 0.7, the average recognition accuracy and recall rate can reach 0.91 and 0.88, respectively, when the labeled ratio was 81.25%. In conclusion, semi-supervised based learning for the intelligent identification and effective management of chrysanthemum flowers had great significance in theory and application for the studying of chrysanthemum phenotype.

Abstract:The bird gait score (GS) is an important tool for evaluating the gait status of broiler. GS0~GS5 corresponds to the broilers whose limping level varies from low to high. The level of limping is used as an important indicator to measure the health of broilers. At present, traditional methods for gait assessment of broiler are mostly completed by visual inspection. The process is timeconsuming with low standardization. The dynamic feature variables extracted from video were used to evaluate the gait status of broilers based on decisiontree, and a fast, stable and noncontact broiler gait evaluation method was explored. The experiment was conducted at Quanjiao Broiler Breeding Center of Wenzhou Group, from December 2017 to January 2018. A total of 260 broilers (GS0~GS4) were selected. Each broiler was subjected to twice walkingexperiments. The experiment was conducted in a special broiler walkway. Two cameras were placed on the opposite side of the walkway and at the top of walkway, and videos were collected horizontally and vertically. Each frame of the video underwent image reorganization, filtering for pretreatment in HSV space. The broiler projection area was calculated by the least squares ellipse fitting based on vertical image, and the dynamic parameters such as the walking speed, stridelength, stridedifference value, and walking steps of the broilers were calculated based on horizontal image. Based on the study of the dynamic parameters of GS0 broilers, the linear fitting relationship between walking speed, stridelength and projection area of broilers was obtained by the least square method, the coefficient of certainty was 0.8051 and 0.7935, respectively. According to the fitting results, based on the different top projection areas of the broiler, the ideal stride and ideal speed of the broiler were proposed. Then, according to the difference between the actual value and the ideal value of the parameters such as stride and speed, the abnormal index of dynamic parameters in broiler walking was defined. Taking the anomaly index, including speed, stride and step difference as training attributes, the C45 decision tree model was optimized for learning and postpruning. Totally 520 data was verified by a 10fold crossover method to obtain the classification result. The accuracy of GS0~GS4 classification was 66%, 71%, 74%, 98% and 95%, and the overall accuracy was 78%. The above results showed that based on the dynamic multifeature variables extracted from video and decision tree model, the quantitative evaluation of limping state of broilers can be achieved. The research result provided a method for assessing the degree of noncontact broilers with high accuracy. The method can be used as an early detection tool for identification and early warning for broilers limping, which provided support for the realization of farming automation and animal welfare industry upgrading, which had certain practical value.

Abstract:During the process of maize production in brown soil in northeast of China, the method of deep burial straw returning can break the plow pan, increase the fertility of deep soil, store water, retain soil moisture and construct a reasonable plough layer structure. Besides, it also solved the problem of effective treatment of straw. The 1JHL-2 type deep burial straw returning machine can complete crushing, collecting, trenching and burying operation of straw that covered the surface at one time. In order to solve the problems such as large ditching resistance, uneven force of whole machine and poor linearity of advancement, the parameter optimization design was carried out on spiral type opener. For the problems of sticking with the soil and blocking easily during ditching, bionic optimization design was applied on the spiral blade surface. Through the kinetic analysis on spiral type opener device, the optimal structural parameters were finally determined. Taking the deep burial rate of straw, power consumption of trenching and maximum deviation of straight travel of the machine as experimental indexes, the forward velocity, rotate speed of spiral type opener and ditching depth as experimental factors, quadratic regression orthogonal rotational combing design with three factors was also used. The experimental results showed that forward velocity of 1.04m/s, rotate speed of 275r/min and ditching depth of 28.5cm were the best parameter combination of working performance. With the optimal parameter combination, the average rate of straw deep burial reached 92.03%, the average power consumption of trenching was 17.7kW and the maximum deviation of straight travel was 74mm, which were verified experimentally in field and met the technical requirements.

Abstract:In order to solve the problem that artificial transplanting of Salvia miltiorrhiza with disadvantage of low efficiency and quality，high labor intensity, and the existing transplanter is not suitable for transplanting nudeseedlings of Salvia miltiorrhiza, and to ensure the erectness rate of mechanized transplanting nakedseedlings of Salvia miltiorrhiza，a kind of fivebar Salvia miltiorrhiza transplanting mechanism was designed，on the basis of establishing the workingconditions constraint and free movement constraint condition of fivebar mechanism and combining the kinematic model，the visual auxiliary interface of the humancomputer interaction was established by using Matlab (Matrix Laboratory). With the help of the auxiliary interface， trajectory location method was used to study the regional trajectory distribution characteristics of the implant endpoint and the influence of the mechanism parameters on the trajectory，according to the trajectory requirements of mechanism, the parameters of fivebar mechanism was got to meet the transplanting requirements of Salvia miltiorrhiza through the numerical cycle comparison method. LA-S series plant image analysis system was used to measure the morphological parameters of Salvia miltiorrhiza，the parameters of duckbill transplanter was designed according to it. Prototype test showed that the transplanting mechanism of Salvia miltiorrhiza based on the fivebar mechanism could meet the requirements of transplanting Salvia miltiorrhiza which can ensure the highlift trajectory，the operation quality and seedling rate of Salvia miltiorrhiza，the seedling qualified rate was 97.3%，the excellent seedling rate was 94%，the leakage rate was 2.5%，the plant spacing variation coefficient was 65%，and the planting depth qualified rate was 94.6%.

Abstract:It is an effective way to reduce chemical fertilizer consumption by changing the fertilization method from traditional strip fertilization to applying fertilizer to concentrated growth zone around the roots of the corn plant. A kind of full layer and hole fertilization of corn seeder was designed. The virtual prototype of fertilizer distributor was designed, and the physical engine in Solidworks was used to carry out the motion simulation of the batch fertilizer and the discharge pipe, and optimize the discharging mechanism to make the fertilizer discharge faster and more concentrated, so that the fertilizer can be applied into the soil in 0.15s. LS-DYNA was used to simulate and analyze the falling fertilizer status of intermittent fertilizer mechanism of the layer and hole fertilization system, and the distribution of fertilizer in soil applied by the layered fertilizer pipe, with the MAT147 soil model and smoothed particle hydrodynamics （SPH）algorithm. The simulation results showed that the mechanism can apply fertilizer to the depth from 7cm to 23cm under the surface of soil, and concentrate in a cylindrical space with diameter of 150mm. The amount of fertilizer in this space was increased with the increase of depth, and the quantity was maximum in the deepest layer, it met the practical application requirements of corn plant growth and reduced unnecessary fertilizer waste. Soil bin test and field test were carried out, and the results agreed well with the simulation results. This novel layer hole fertilization can effectively reduce the consumption of chemical fertilizer.

Abstract:Cultivation can remove weeds between the ridges, improve the nutritional conditions of tobacco, and increase the ability of lodging resistance and yield of tobacco during the growth in field. In order to improve the quality and efficiency of field management and cultivation and hilling during tobacco’s middle tillage, a tobacco hilling machine for compound cutting was designed. Based on the prototype, key parts were analyzed and designed, and the principle of compound cutting was clarified. The structure and operation parameters of adjustment device of ridge distance, ridge shape angle, ridge bottom width and hydraulic transmission system were determined. The oblique cutting of the plough and the milling of the spiral earth cutter were analyzed, and the positive milling and reverse milling of the spiral earth cutter were tested. The results showed that the working effect of the spiral earth cutter was better in the reverse milling. At the same time, the operation process of hilling of assembling for compound cutting was analyzed, and the necessary work conditions to make sure that the minimum speed and geometric parameter of spiral soil knife were obtained by analysis and calculation. For the relevant work performance test of prototype, the field experimental results showed that under the condition of operation speed of 2.5 ~ 3.2km/h, the soilbreaking rate was 90%, the qualification rate of hilling thickness was 95%, the qualification rate of ridge shape angle was 93%, the hilling of height was 400mm, the width of furrow was 750mm. The test results met the design and practical requirements. The research conclusion had great theoretical value and practical significance to the design of machine which worked for tobacco hilling.

Abstract:The discrete element boundary parameters have an important influence on the simulation accuracy. In order to improve the simulation accuracy, big urea particles were taken as the research object, the macroscopic phenomenon of the repose angle which reflected stacking process of granular particles was chosen, and the Plackett-Burman screening test was used to select the factors which was important based on the angle of repose. The order of importance for determining the effect was the rolling friction coefficient between urea particles, the static friction coefficient between urea particles and the static friction coefficient between particles and ABS plates, and the three boundary parameters influencing the accumulation of urea particles, the angle of repose was increased with the increase of the three boundary parameters. The static friction coefficient, the static friction coefficient between particles and ABS plate and the coefficient of rolling friction between particles were studied by selfmade static friction coefficient measuring instrument and virtual simulation calibration method, respectively. And the simulation and test verification of accumulating process of determined values were carried out. The relative error between the simulation repose angle and the actual test repose angle was only 0.36%. The relative error between the calibrated simulation repose angle and the actual test repose angle with different water contents was not more than 3.25%. The test results verified the validity of the boundary parameters and the simulation model. A new method for calibrating urea particle simulation boundary parameters was proposed. The validity of the calibrated discrete element model and boundary parameters of the urea particles was improved. The calibrated discrete element model and boundary parameters of the urea particles and calibration method can be applied to the dynamic simulation of the fertilizer distributor.

Abstract:Aiming at the status that the mechanism study of the chopper device in sugarcane harvester is insufficient，chopping loss is high, and the requirements to the chopper device present the character of diversification, three different harvest processes varied in the mounting position of the chopper device were compared and analyzed, including frontmounted, centralmounted and rearmounted. Based on the analysis result of the merit and demerit between different harvest processes, the viewpoint that the harvest process which adopted frontmounted structure of chopper device was more suitable for the bending and lodging sugarcane in China was proposed. Further theoretical analysis of the frontmounted structure was conducted and empirical formula of billet length produced under this structure was deduced. Based on this, a chopper testing unit was designed, as well as a new type header of sugarcane harvester charactered by frontmounter chopper. A highspeed photography test was conducted on the testing unit and law of motion of billets and canestalk was observed, as well as the separation process between stalk and leaf, furthermore, sugar loss during chopping process was analyzed through the procedure of fracture formation. Taking the billet acceptability as index, and through orthogonal field test conducted on the header, the factors impacted on billet quality were optimized, and the billet acceptability reached up to 93% under the condition that intersect depth was 4mm, ground speed was 2km/h，and rotational speed of rollers was 300r/min. By means of billet length test and statistical analysis, a conclusion was drawn that billet length was approximately in normal distribution, and the length coefficient in aforesaid formula was deduced as 0.7.

Abstract:In order to solve the problems of soybean grain mixing and mechanical damage caused by single threshing process of soybean. A threshing device was designed for singleplant thresher with differential speed flexible belts. Single threshing was an important part of breeding experiments because it can avoid mixed seeds when there was smaller breeding area, small sample size and precious varieties. Meanwhile, most of the existing threshing devices were rollertype and made by rigid materials, which could cause mechanical damage to the soybean grains easily. However, the new soybean threshing device solved the problem of mechanical damage which would affect the germination and emergence of soybean seeds. And in order to find the optimal combination of the structure and working parameters of the differential flexible belt type soybean thresher, the method of fourfactor with fivelevel quadratic regression orthogonal rotation center combination was employed. The factor of cylinder clearance, top and low section velocity difference, low section velocity, threshing trip were discussed. And the loss of unthreshed grain, loss of entrap grain, cracked grains and average productivity were selected as evaluating indexes. The results showed that the rank of the effect of four factors on loss of unthreshed grain from high to low was as follows: top and low section velocity difference, the cylinder clearance, low section velocity and threshing trip; on loss of entrap grain: low section velocity, the cylinder clearance, threshing trip, top and low section velocity difference; on cracked grains: the cylinder clearance, top and low section velocity difference, threshing trip and low section velocity; on average productivity: threshing trip, low section velocity difference, the cylinder clearance, top and low section velocity difference. In the case of soybean grain with 16%~18% moisture content, the optimum combination region of the 〖JP2〗cylinder clearance was 7.55~13.00mm, the top and low section velocity difference was 0.59~0.70m/s,〖JP〗 the low section velocity difference was 0.84m/s, the threshing trip was 660mm; under this condition, loss of unthreshed grain was less than 12%, loss of entrap grain was less than 09%, cracked grains were less than 0.8%, average productivity was more than 35kg/h. The results laid a theoretical foundation for the development of singleplant thresher with differential speed flexible belts.

Abstract:In recent years, furrowridge potato cultivation with global plastic film mulching technology is widely used in the semiarid areas of the Loess Plateau, this kind of cultivation mode is favorable for mechanical planting, but the difficulty of machine harvest is increased. In order to solve the problems of blockage in the process of digging, poor separation effect, low reliability and white pollution for the complete film mulching, planting line covering and ridge sowing pattern in the dry land of northwestern Chinese Loess Plateau, a potato digger with waste film recollection was designed, which can complete the antiblocking digging, potato separating from soil and film, potato collection and striping, disconnecting the film away from the residue seedlings and the waste film recollection in one process. By theoretical analysis and numerical simulation, the crucial parts, such as bionic digging device, antiblocking crank rocker mechanism, potato and soil separation device, potato and film partition device, residue seedlings and film disconnection device, the waste film recollection components as well as others were analyzed and optimized, and then the performance parameters were determined. Field experiments showed that the potato exposure rate was 97.4%, the potato injury rate was 1.3%, the potato skin damage was 1.8%, the waste film recollection rate was 87.5%, and the productivity can get to 0.17hm2/h, all the index of the potato digger with waste film recollection satisfied the requirements of national and industry standards, the problems such as the mulched potato harvesting and the waste film recollection were solved at the same time.

Abstract:It is a dilemma to solve the picking mechanization of camellia fruit in the camellia industry, of which camellia bud damage is a bottleneck. A motordriven picking actuator of camellia fruit with rotate rubber roller was developed. The principle of camellia fruit picking by rotate rubber roller was analyzed. The interaction between camellia fruit and rotate rubber roller can be summarized as contact, impact and abscission during the process of camellia fruit picking by rotate rubber roller, through which corresponding forces were derived and the critical condition of camellia fruit’s falling off was obtained. By analyzing the parameters of swinging strut of picking head, the efficient adjustable range between upper and lower rubber roller of swinging strut was designed as from 20mm to 65mm, and the preliminary rotate speed was proposed from 20r/min to 40r/min. Tests of camellia fruit picking and its bud damaging were conducted in the camellia forest of Jiangxi Agricultural University when the prototype was completed. Experimental results showed that as the diameter of rubber roller was 30mm, the rotate speed was 30r/min, the linear velocity was 0.833m/s, and the gap between up and down of rubber roller was 25mm, the diameter of camellia fruit above 25mm can be harvested by rotate rubber roller, the percentage of residual camellia fruits on the camellia branches was 13.6%. What’s more, the damage of unopened camellia bud was bare, which verified the practicability of this prototype and provided the reference for the development of camellia fruit picking machine.

Abstract:Aiming at the problems of conveying powder feed by spiral springs and plug plates such as the clean of residue and the measurement of feed quantity, an automatic feeding conveying system consisted of weighing platform, feeding vehicle, translational orbit, overhead orbit and control system was designed. The design of feeding vehicle, orbit and parameters were determined by the relationship between the inner pigpen and the cruise time. Combined with the negative feedback control method of weighing sensor, the WiFi wireless control system was designed with Arduino control board. The system can realize automatic cruise control of feeding vehicle’s loading and unloading, automatic measurement of loading quantity by weighing platform and the joint of weighing platform and the orbits by translational orbit mechanism. The experiment was made with powdery feed at China Agricultural University Shangzhuang Experimental Station. The results indicated that the difference between the relative standard deviation of the weighing system measured value and the actual measured value was less than 1%, 〖JP3〗the maximum relative standard deviation of the system measured value was less than 2.5%, and the weighing system had a high degree of accuracy. Additionally, controlled by the system, the feeding vehicle can complete loading, cruising and unloading functions according to requirements to realize two rows of pigpen feeding. The orbital feeding system had practical application value for precise feeding in the pig house.

Abstract:Vertical inline pump is a singlestage single suction centrifugal pump with a bent pipe before the impeller, which is usually used in where the constraint is installation space such as pumphouses. But these unavoidable bents before the impeller inlet also result in the hydraulic losses at the entry of the pump and the decrease of efficiency. In order to improve the performance of a vertical inline pump, an optimization on inlet pipe was proposed based on artificial neural network (ANN) and particle swarm optimization (PSO). The profile of inlet pipe was controlled by the mid curve and the shape of cross sections. The shape of mid curve was fitted by using a fifth ordered Bezier curve and the trend of parameters of cross sections along the mid curve were fitted by third ordered Bezier curves. Considering the real installation of the pump, totally 11 design parameters of inlet pipe were set as the design variables and the efficiency of the pump was set as the objective function. In order to build highprecision ANN model between the objective function and the 11 design variables, totally 149 groups of sample data were created by using Latin hypercube sampling. After that, the ANN model was solved for the optimum solution of the design variables of inlet pipe by using particle swarm optimization. The result showed that there was a good agreement between computational results and experimental results; the ANN model could accurately fit the objective function and variables, the deviation between predicted value and actual value was 0.32%; after optimization, the efficiency and head of the pump was increased by 1.17 percentage points and 0.23m, respectively. The highefficiency period was also expended. Compared with the original inlet pipe, the flow condition in inlet pipe was improved after optimization.

Abstract:In order to research the internal sound field characteristics and reduce the running noise of vertical pipeline pump, the CFD and Lighthill sound analogy theory was adopted to solve the internal flow and acoustic field. The sawtooth structure of the owl feather was used to conduct bionic optimization to reduce noise. Firstly, the pressure fluctuation of pipeline pump at 0.8Qd, Qd and 1.2Qd were obtained from the unsteady simulation with the RNG k-ε turbulence model in CFX software. The datum of pressure fluctuation were extracted and input into the LMS Virtual.lab acoustics software, the SPL of the pump discharge, internal sound pressure distribution and main noise source in pumps at different flows were got by acoustic field calculation. The simulation results showed that the flowinduced noise of pipeline pump was closely related to the pressure fluctuation which was mainly caused by rotorstator interaction，both of them had the same frequency characteristic, the sound pressure was mainly distributed in shaft frequency, blade frequency and frequency multiplication, the maximum sound pressure appeared at 1 time blade passing frequency. With the decrease of the flow rate, the SPL of the pump discharge was increased. Then, based on the bionics principle, the similarity criterion was used to establish the bionic blade model with reference to the structure characteristics of the specimen of the owl wings. Three parameters, including tooth width, tooth pitch and tooth width were constructed to control the geometry of the bionic blade，and these parameters were chosen to design 16 orthogonal test models. Finally, the internal flow and sound field datum of different impellers under different working conditions were got by calculation. Compared with the optimal model，the result showed that the bionic blade with sawtooth structures can reduce the pressure fluctuation, stabilize the flow field and reduce the noise. Noise reduction was obvious under the design condition, and the noise of the blade frequency was decreased as high as 8dB.

Abstract:Remote sensing images with medium spatial resolution and multiband can provide data source for crop classification on country scale. Based on analysis of the spectral characteristics of single image and its vegetation index, the identification and acreage extraction of major autumn crops can be effectively achieved. Taking Puyang County, Henan Province as study area, and basic image with 13 bands and spatial resolution of 10m, which was collected on August 6th, 2017 was employed. Combined with the ground samples and sample points data, the spectrum curve characteristics, including NDVI and RENDVI of the major crop types (corn, peanut, soybean, rice and minor crops such as vegetables, sweet potato, etc.) in this growth period were extracted. Through the analysis of spectrum curve characteristics of different crop types, it can divide the basic image into different regions by building decision tree, which was built by the threshold segmentation of vegetation index features, and band math tool in ENVI software. Based on curve characteristics of NDVI, the basic image data can tripartite regions such as major crop planting region, noncrop planting region and minor crops planting region. Then on the basis of major crop planting region image and its RENDVI data, it can divide this region into two regional images, including corn/rice and peanut/soybean. Finally, synthesizing the above results, five crop types in the study area were classified by SVM and limited training samples. The precision of the results by using decision tree and SVM was evaluated compared with ML and SVM methods, which were gradually adjusted according to the validation of field samples and sample points. The method can effectively solve problems such as incomplete extraction of linear object, different crops in small plots, and also phenomena of “salt and pepper”. Its overall accuracy and Kappa coefficient reached 92.3% and 0.886, respectively. The precision of classification can meet the demand of remote sensing image classification by analyzing spectral characteristics and vegetation index. Based on mono temporal Sentinel-2A data, it can provide data support and technical reference for regional complex crop classification extraction.

Abstract:The phenomena of different objects having the same spectrum and the same objects having different spectrum bring inconsistency for the same endmember. The existing of endmember variability issue will lead the process of endmember selection and extraction more difficult and decrease the final unmixing accuracy. Aiming to minimize the intraclass variability and maximize the interclass variability, a new method named weighted coefficient of variation analysis (WCVA), which permitted the comparison of variants free from scale effects and made the weighting become more automatic, was proposed for multispectral data. It was on the basis of coefficient of variation (CV) and weighting theory. The proposed method was successfully indicated from theoretical and experimental parts. The comparison with the commonly used optimal index factor (OIF) was conducted in terms of visualizing the spatial distribution of all available band combinations, efficiency and the final unmixing accuracy by fully constrained least squares (FCLS) and post polynomial postnonlinear mixture (PPNM) with TM and GeoEye images in the same research area. In the experimental results, the unmixing accuracy (0.183 and 0.160) based on the feature combination selected by WCVA was higher than that by OIF. Meanwhile, the computation of WCVA was much less than that of OIF as well. The results showed that WCVA not only had benefits for solving endmember variability issue and enhancing the unmixing accuracy, but also had higher efficiency.

Abstract:At present, the research trends and hotspots of regional soil erosion are related to efficiently accessing a large amount of soil erosion factors raster data, quickly calculating and publishing the date of soil erosion intensity. To solve these problem, a GIS was constructed, which consisted of the distributed storage of soil erosion factor raster data, the parallel computing program to calculate soil erosion intensity and the quickly publishing program of soil erosion intensity, based on the latest open source project called Hadoop. Then an experiment of calculating the DaLing River Basin’s soil erosion intensity was taken through the system. The result showed that initially the system can much effectively calculate DaLing River Basin’s soil erosion intensity from a large amount of soil erosion factors raster data. Furthermore, the system can fulfill the requirement of regional soil erosion intensity prediction and forecast. Additionally, in the process of running the program, the localization effect of the calculation task was very obvious, the network transmission pressure in the calculation process was significantly reduced, the network usage rate was maintained at about 22%, and the system performance can be further improved by adding computing nodes. Finally, the studies can provide guidance for GIS design and development of regional soil erosion intensity calculating and publishing with a large amount of highresolution raster data, and provide scientific basis for soil erosion monitoring in DaLing River Basin.

Abstract:With the appearance and continuous development of the Internet of things, the monitoring data grows explosively. Accordingly, traditional data storage and processing can not meet the requirements．In order to store data effectively and query data in real time, intelligent monitoring and management system based on Hadoop for largescale layer house was developed. The HDFS file system and HBase database in the Hadoop ecosystem can store massive data distributed. The environmental monitoring data had the characteristics of once writing and multiple queries. In order to realize the realtime monitoring and largescale data query for environmental data, MySQL database was used to store recent data and HBase database was used to store historical data. Experiments indicated that the query speed was improved effectively. For the unified management of massive heterogeneous video data, the distributed transcoding of video was designed and implemented. Experimental results showed that the proposed scheme can increase about 50% of the transcoding efficiency when the video size was 1.5GB and the segment size was 128MB. The system realized realtime information display, historical information query, infrastructure management, production process management and statistical data analysis, environmental alerts and system management in production and breeding of largescale layer house, which can be accessed through web pages and mobile APP by users in real time. The actual application showed that the system helped managers to control the production process on all aspects and improve the efficiency of the production personnel.

Abstract:In order to realize the demand of low power sensor for pneumatic system, a new type of magneticassisted piezoelectric energy harvester was proposed and it can promote the efficiency of harvesting the dynamic high air. The noncontact force between the magnets was used as magnetic induced prestress acted on the center of the piezoelectric circular diaphragm. The magnetic induced prestress can adjust the surface charge distribution of the piezoelectric circular diaphragm when the dynamic air pressure acted on the piezoelectric circular diaphragm. The simulation research showed that the repulsive force increased the output power of the magneticassisted piezoelectric plate harvester, while the attractive force decreased the output power of the magneticassisted piezoelectric plate harvester. The diameter and thickness of piezoelectric unimorph were 22mm and 0.23mm, respectively. The diameter and distance of cylinder were 63mm and 150mm, respectively, and the prototype of the magneticassisted piezoelectric plate harvester was fabricated. The test system was built to research the rules and performances of the magneticassisted piezoelectric plate harvester. In the test, the pressure, cycle, flow and the magnets distances were adjusted. Experimental results showed that the instantaneous power was 1.39mW when the optimal load resistance was 0.87MΩ, and the output power of the generator was promoted 12.6%, while the magnetic induced prestress was only about 0.6% of the hyperbaric air load. Therefore, the magnetic induced prestress can effectively improve the efficiency of the dynamic high air in the pneumatic system.

Abstract:A parameter adaptive differential evolution algorithm was proposed to measure the diameter at breast height (DBH) of tree trunk by fitting circle. A DBH measuring platform made by laboratory was utilized to collect the data, and the Kmeans algorithm was first introduced to cluster the data and segment the background and target. In order to improve the fitting accuracy, the angle compensation method used arc length was employed to compensate the deflection angle of the trunk surface point to the laser sensor center before fitting. Then, the center of laser sensor was taken as the coordinate origin, and the horizontal and vertical coordinates of the trunk surface points were calculated. Finally, the adaptive differential evolution algorithm was proposed to fit the tree trunk surface. In the process of fitting, the number of population, evolutionary strategy, scaling factor and crossover rate of the differential evolution process were adaptively changed with the evolution process. Totally forty different sizes of trees in the campus and artificial forest were measured and fitted respectively, and the fitting time was 1.41s. The results of the proposed method were compared with the real values of DBH. The RMSE for DBH of trees in the campus and artificial forest were 4.996mm and 4.500mm, respectively. At the same time, the results were compared with the Levenberg-Marquardt (LM), particle swarm optimization (PSO) and Hough transform. The experiments validated that the method proposed can measure the DBH more effectively and accurately.

Abstract:In order to measure the tree diameter at breast height (DBH) rapidly, efficiently and accurately, and improve the work efficiency of forest resource investigation, a portable high precision equipment for measuring tree DBH was developed. This equipment was integrated by central processing unit (CPU）, DBH sensor, liquid crystal display (LCD), storage, wireless communication module and so on. The DBH sensor was developed independently by this experiment. The principle of the DBH sensor was to convert the measured length information into voltage signal by using electronic technology and mechanical principle. The voltage signal would be calculated by CPU and the measured value of DBH was obtained. Wireless communication was used to cooperate with the mobile phone that installed with the data receiving terminal APP. It can achieve the functions of DBH measurement, data encoding, data recording, data editing, data storage and data export. According to the results of the test data, the measurement accuracy of this equipment for different tree species reached more than 99.97%. This device can adapt to different kinds of trees and different diameter trees, which accorded with the national survey accuracy standard of continuous forest inventory. And the measuring efficiency of this equipment was more than twice higher than that of traditional diameter gauge.

Abstract:Crop model is an important tool to simulate crop growth and yield, which can provide a way to cope with the impacts of climate change and human activities, and achieve the target of saving water and increasing yield. Film mulching and watersaving irrigation are widely used in the arid regions of Northwest China. Therefore, the purpose was to modify the crop model AquaCrop based on compensating effect of soil temperature increase on effective air accumulation temperature and impacts of film mulching and canopy interception on rainfall infiltration, so as to make it more suitable for the simulation study of mulched seedmaize in arid areas. The modified model was calibrated and validated based on the experimental data of seedmaize in Shiyang River Basin in 2017. Then it was used to predict the variation of crop yield and water use efficiency (WUE) under the scenarios of future temperature increase and mulching ratio change. Results show that the modified AquaCrop can well predict the growth stages and canopy cover. The values of determination coefficient (R2) of the simulated and measured canopy covers were not less than 095, the values of root mean square error (RMSE) were between 3.9% and 10.1%, and the values of normalized root mean square error (NRMSE) were between 4.9% and 15.3%, indicating that the modified AquaCrop had a good simulation for canopy cover. The modified AquaCrop was validated for simulating soil water storage in 0~1m soil depth under different treatments with 0.60

Abstract:Ridge-furrow with plastic film mulching planting is commonly used in Northwest China because it can obviously increase yield, but it is still unknown whether the effect of increasing yield is based on consuming more water or not. In order to explore above question, field experiments were conducted in Yangling of Shaanxi Province for three maize seasons with two treatments of ridge-furrow with plastic film mulching planting (RM) and flat field without mulching (NM). The HYDRUS-2D model combined with field experiment was also used to study soil water movement. The simulated results showed that HYDRUS-2D model performed well for simulating the movement of soil water, the coefficient of determination R2 was between 0.65 and 0.85, the root mean square error (RMSE) was between 0.0147cm3/cm3 and 0.0213cm3/cm3, both were in suitable range. Transpiration rate and cumulative transpiration of RM were 18.2% and 15.6% larger than those of NM, respectively. RM decreased evaporation rate and cumulative evaporation by 33.3% and 29.6%, respectively. The value of E/ET (ratio between evaporation and evapotranspiration) was also decreased under RM by 25.5%, but leakage of deep water of RM was 82.5mm, 46.0mm and 9.0mm for three years, which were about 1.3 times as large as that of NM. Summer maize yield and water use efficiency of RM were increased by 5.3% and 15.2%, respectively, and water consumption of field was reduced by 2.8%. The research result showed that RM treatment can change the water consumption structure of crop and make soil water to be more available for crop, because it can increase the maize transpiration and decrease the soil evaporation, thus decrease the water consumption of field, so it was profitable in Northwest China.

Abstract:In order to explore the response of growth physiological characteristic and yield of rice to the water consumption process in black soil region, the experiment was carried out by lysimeter at the rice irrigation experiment station of Heilongjiang Province in 2017. The U7（7.6） experiment was conducted to analyze the effects of water consumption at each stage on growth physiological characteristic and yield of rice. The results showed that the water consumption intensity during the growth period of rice generally showed a trend of rising firstly and then decreasing, the maximum water consumption intensity at headingflowering stage was 5.66mm/d; the maximum water consumption percentage during the whole tillering stage was 43.98%, which tended to be stable after the headingflowering stage. The water consumption at the late tillering stage had the greatest influence on dry matter weight of rice leaf; the dry matter weight of stem sheath and spike had significant response to the water consumption at jointingbooting stage and headingflowering stage (P<0.01); the water consumption at the midtillering stage and late tillering stage showed a greatest positive and negative effects on dry matter weight of root, respectively; except for the early tillering stage, the effect of water consumption from the midtillering stage to headingflowering stage on the amount of bleeding of root was represented as ET2, ET3, ET4 and ET5; the water consumption at the midtillering stage, jointingbooting stage and headingflowering stage had a positive effect on Gs and Tr （P<005）; the water consumption at the early tillering stage showed a negative effect on Tr （P<0.05）; except for ET1, the effect of water consumption from the midtillering stage to headingflowering stage on Ci and Pn were represented as ET5, ET2, ET4, ET3 and ET2, ET5, ET4 and ET3，respectively. The λ at the midtillering stage, jointingbooting stage and headingflowering stage were 0.120, 0.244 and 0.252, respectively, and the water consumption of these three stages had more significant effects on rice yield. The research result would provide a basis for making watersaving irrigation of rice in black soil region.

Abstract:The aboveground biomass and yield of winter wheat depend on intercepted photosynthetically active radiation (PAR) by crop canopy and radiation use efficiency (RUE). At present, many successful crop growth models estimate aboveground biomass accumulation and yield formation based on fraction of intercepted PAR (FIPAR) and RUE. In order to investigate the influences of water stress on FIPAR and RUE of winter wheat at different growth stages, field experiments of winter wheat were conducted under a rainout shelter in two growing seasons (2015—2016 and 2016—2017) in Yangling, Shaanxi Province. The experimental design involved four different treatments of water stress: no irrigation at greening and jointing stages (namely the early stress, ES), no irrigation at heading and filling stages (namely the later stress, LS), no irrigation at all stages (namely whole stress, WS), and full irrigation at all stages (namely CK). The irrigation level was 80mm. The incident solar radiation by the canopy was continuously measured all day with PAR sensors installed at the center of each plot. The results showed that the relative available soil water content can effectively reflect water status of winter wheat under different drought treatments. The maximum leaf area index (LAI) of ES, LS and WS were 31%, 15% and 58% lower than that of CK treatment, respectively. Affected by LAI, the maximum FIPAR of CK, ES, LS and WS were 90%, 88%, 79% and 42%, respectively. And the WS treatment was significantly lower than the other three treatments for the maximum FIPAR. Meanwhile, the difference of LAI and FIPAR among different treatments resulted in different extinction coefficient, especially the extinction coefficient of ES is lower than that of LS. The averaged aboveground biomass of CK, ES, LS and WS treatments across the two growing seasons were 1532g/m2, 1410g/m2, 1403g/m2 and 537g/m2, respectively. For RUE of winter wheat, the CK treatment was 355g/MJ, and the ES and LS treatments were 22% and 5% lower than the CK treatment, in addition, the WS treatment was 22% lower than CK. The RUE of winter wheat was firstly increased and then decreased through whole development season, and peaked at the flowering stage. The RUE reduction of winter wheat caused by water stress in the vegetative stage was greater than that in the reproductive stage under water stress. The RUE of winter wheat under the WS treatment showed very different responding mechanisms to water stress, which needed further study. The research result suggested that if the extinction coefficient and RUE that can be treated as a function of growth stage or thermal time accumulated temperature rather than a single constant, the estimation accuracy of dry matter in the current model could be improved and the uncertainties of the model could be reduced under serious water stress. 

Abstract:In order to define the optimum application rate of nitrogen fertilizer under the condition of straw returning in Yanghuang Irrigation Area of Ningxia，the treatment with no straw returning (N0) as the control，the effects of different nitrogen application rates (0kg/hm2 (N0)，150kg/hm2 (N1)，300kg/hm2(N2) and 450kg/hm2(N3)) on soil organic carbon and nitrogen，microbial biomass carbon and nitrogen content，soil enzyme activity，and maize growth were investigated．The results showed that the straw returning with an optimum application rate of nitrogen was useful for increasing soil organic carbon and total nitrogen at 0~40cm layer，and the contents of soil organic carbon，total nitrogen with N2 and N3 were significantly increased，compared with N0．The ration of carbon to nitrogen was decreased with the increase of application rate of nitrogen under the condition of straw returning．The treatment with straw returning and nitrogen application significantly increase the soil microbial biomass carbon and nitrogen compared with straw returning and no nitrogen fertilizer treatment，and the ratio of microbial biomass carbon to microbial biomass nitrogen was decreased with the increase of nitrogen application rate．The improvement effects of soil microbial biomass carbon with N2 and soil microbial biomass nitrogen with N3 were the most significant．Straw returning with nitrogen application could significantly improve the activities of soil urease，catalane，alkaliphosphata，and sucrase，and the improvement effect of soil enzyme activities with N2 and N3 were the best．The effect of N2 on maize growth at middleandlate stages were great，while it had no effects on maize growth at early stage．The maize grain yield and water use efficiency enhancement were the highest under N2．The 2year mean maize grain yields with N2 were significantly increased by 220%，compared with N0．The 2year results indicated that straw returning with application of nitrogen can increase the soil organic carbon and total nitrogen contents，regulate the ration of carbon to nitrogen，increase the soil microbial biomass carbon and nitrogen and enzyme activity，thus improving maize growth and grain yield in Yanghuang Irrigation Area of Ningxia．The straw returning with application of pure nitrogen of 300kg/hm2 was the best．

Abstract:The residue of plastic mulching and premature aging due to high soil temperature at late stage of crop growth would be caused by white plastic film mulching at arid area in northern China, so the main object was choosing the optimal green film mulching. The nine treatments were experimented, including the white and black rapid (WO1 and BO1), medium (WO2 and BO2) , low (WO3 and BO3) degradation film and white and black plastic film (WP and BP), no mulching (CK) to study the effects of different film mulchings on the film damaging and maize yield, and explore instant surface temperature, soil temperature for every hour and every day based on infrared imaging and continuous monitoring technique. The result showed that the proportion of film damaging for black degradation film was higher than that of white degradation film, which was 8.4% after 130d mulching. The higher rank of instant surface temperature was in the order of black film, white film and no film, and the average soil temperature in growth stage was 3410℃, 32.34℃ and 29.12℃, respectively （P<0.05). The higher rank of soil temperature for every hour and every day was in the order of white film, black film and no film, and black film mulching could reduce soil temperature by 1.1℃ of 0~15cm soil layer at daily highest temperature time compared with white film mulching. The average soil temperature difference reached 1.13℃ （P＜0.05) between white and black film mulching at the maize early and late growth stages (May and September), however, it was just 0.45℃ at the maize middle growth stages (from June to August). The proportion of film damaging was influenced by film degradation rate, and it would influence the variability of temperature distribution in space and heat preservation effect. Therefore, lower film degradation rate, less film damaging, and the close heat preservation effect between plastic film and low degradation film mulching. The soil temperature difference for WP, WO3 and WO2 treatments compared with WO1 treatment, respectively, was 3.03℃, 2.70℃ and 1.05℃（P＜0.05), and 3.00℃, 2.57℃ and 1.01℃（P＜0.05) for corresponding black film mulch. There was no difference for maize yield between low degradation film and plastic film whether black or white film mulching. However, there was significant difference among different degradation rates film mulching under same color film mulching （P＜0.05). The higher rank of maize yield for different degradation rates film mulching was in the order of low, middle and rapid degradation film mulching. So, the black film mulching with the best heat preservation effect and higher yield could reduce surface soil temperature at late growth stages, and there were close heat preservation and yieldincreasing effect between black low degradation film and plastic film mulching. It was feasible for developing agriculture in arid areas, northern China to replace white plastic film mulching with black low degradation film mulching.

Abstract:The crop growth model has distinct advantages of clear mechanism and dynamic serial simulation, and it has been widely used in regional crop production forecasting. The research focused on the major problem that the uncertainty of yield prediction with crop model can not be quantized and the issue that the realtime impact of meteorological driving factors on crop model was not timely reflected. Simulations in the main wheat production areas in Baoding and Hengshui of Hebei Province were conducted and a method was proposed to build a historical meteorological dataset as weather inputs to drive the WOFOST model to simulate wheat growth during the forecasting period. Then the yield was continuously forecasted through realtime updating. In this way, the traditional singlevalue forecasting of yield was changed to an ensemblebased probabilistic forecasting, and the regional yield ensemble forecast and event possibility forecast can be generated in everyday in the growing season. The validation results indicated that the WOFOST model with historical meteorological data was able to reflect the uncertainty of regional weather data. In the regional ensemble forecasting of wheat yield, the highest yield forecasting accuracy was achieved in the period from heading to grain filling stage. The correlation coefficient (PCC) between the ensemble mean and the measured yields was 0563, while the minimum average absolute error (MAE) was 458kg/hm2, however, the improvement of yield forecasting accuracy along with forecasting date was slow, because simulation with homogeneous input parameters in potential level was a little coarse. It suggested that with the help of remote sensing data assimilation or medium weather numeric forecasting, yield prediction could achieve better accuracy. The results showed that the regional yield ensemble forecast had strong feasibility, and this research provided a reference for the application of numerical weather forecast and quantification of the uncertainty in crop simulation system.

Abstract:There is no universally accepted approach for evaluating lead (Pb) bioavailability in soil. The diffusive gradient in thinfilms (DGT) technique is a promising tool which has been used for evaluating the bioavailability of heavy metals in water and sediment. The principle of DGT is based on Fick’s first law of diffusion. The ability of this technique to estimate Pb bioavailability in soils was compared with the abilities of other traditional chemical extraction techniques (soil solution, ethylene diamine tetraacetic acid (EDTA), acetic acid (HAc), calcium chloride (CaCl2), and pseudototal Pb methods) based on a greenhouse experiment using Brassica chinensis grown in 15 soils from different provinces of China. In addition, whether these methods were independent of soil properties were assessed. Correlations between the plant and soil Pb concentrations measured with the traditional extraction techniques were dependent on the pH value and organic carbon (OC) content, indicating that these methods were influenced by the soil properties. The regression coefficients (R2) were increased when these prediction models, including soil properties (pH value and OC) though the stepwise multiple linear regressions compared with simple linear regressions besides DGT method. In contrast, the DGT measurements were independent of the soil properties and showed a higher correlation coefficient compared with that of the traditional techniques. And the prediction model built by DGT (R2=0.97, p＜0.01) showed a highest R2. Hence, the DGT technique was better and should be preferable for assessing Pb biological effectiveness in different soil types.

Abstract:A new BP network model was developed to improve the accuracy and assess the groundwater quality. For this purpose, the krill herd algorithm (KHA) was established with the optimization process of the connection weights and thresholds of the BP neural network. Totally 15 farms were selected to evaluate the groundwater quality and identify the main causes of groundwater pollution in Jiansanjiang Administration. In addition, to verify the applicability of the model, the distinction degree method and the theory of serial number summation were used to analyze the reliability and stability of KHA-BP model, PSO-BP model and BP model, respectively. The results exhibited a good agreement of groundwater quality in each farm and there was a certain spatial distribution pattern such as the water quality of grade I was mainly concentrated in the southwest position, grade Ⅱ was distributed in the north and south, while the grade Ⅲ was located in the midwest and mideast of the administration. Fe, Mn, CODMn, NH3N and NO-3N were the main factors caused groundwater pollution. Fe and Mn were local primary hazard but excessive amounts of CODMn, NH3N and NO-3N were mainly related to use of a large number of fertilizers and pesticides. The distinction degree of KHA-BP was 1.1070 and Spearman’s rank coefficient was 0.9286, which was better than those of PSO-BP and BP. In conclusion, this research could provide a scientific basis for the comprehensive management of groundwater resources and construction of water ecological civilization in the core areas of food production.

Abstract:A new type of trough solarconcentrating carbon dioxide generator was designed. The heat collection and gas production performance of the generator was tested under the tracking and nontracking conditions in Huhhot, and the changing rules of the reactor cavity stagnation temperature, integral water temperature and heatcollecting efficiency with the irradiance at the daylight opening were analyzed, the optimal operation mode of the system was determined and two system performance evaluation indexes of gas loss rate and gas production capacity were proposed. The test results showed that the determination coefficient of the fitting formulas were both greater than 0.998 after the calibration with two thermocouples, and the fitting function had high accuracy. During the test, the fitting curve equation was used to correct each test temperature value. The No.1 thermocouple tested the generator cavity temperature, which was installed in the center of the cavity. The No.2 thermocouple was installed close to the outer wall to test the temperature of the outer wall of the generator. Under the two conditions, the change rules of the system performance parameters were similar, but there were also features in common. The temperature of each test point and gas production capacity had positive correlation with the irradiance. The heat generation efficiency of the system was mainly affected by the initial temperature of the heat storage medium, and the higher the initial temperature of the heat storage medium was, the lower the heatcollecting efficiency of the system would be. When the temperature of the heat storage medium approached the limit temperature, the higher solar irradiance was needed to supply the system heat loss and then continue to enhance its heat storage. Under tracking and nontracking conditions, the maximum stagnation temperatures of the reactor were 107℃ and 92℃, respectively. Compared with the nontracking conditions, the maximum stagnation temperatures of the reactor cavity was increased by 1630% under tracking conditions. Under the conditions of tracking and nontracking, the maximum integral water temperatures of the reactor were up to 94℃ and 83.6℃ and the highest heat concentration efficiency were 38.90% and 20.00%, respectively. Compared with the nontracking conditions, the maximum water temperature in the reactor cavity was increased by 12.44% and the maximum heat concentration efficiency of the system was increased by 94.50% under tracking condition. During the test period, the minimum water temperature in the reactor cavity was 62.4℃, which was higher than the complete decomposition temperature of the reaction raw materials. Integral temperature of reactor was less influenced by ambient temperature. The best operation condition of the system was determined to be tracking model. The heatcollecting efficiency of the system was 31.80% within the gas generation temperature range, and the gas loss rate was 450% during the whole gas production process. When the solar direct irradiance was ranged from 650W/m2 to 850W/m2, the gas generation capacity of the system showed a positive correlation with the solar direct irradiance lower than 700W/m2, the gas production capacity gradually tended to be steady, and the gas loss approached the limit value, and the decomposition speed tended to be stable. The relationship between gas production capacity and solar direct irradiance was obtained. Based on the gas production capacity, the determination method of specific structural parameters of line focus solar carbon dioxide generator under the best mode of operation can be determined. The research result was of great significance for promoting the standardized application of the line focus solar carbon dioxide generator.

Abstract:The enzymatic hydrolysis and biogas fermentation of rice straw were studied. The effects of combined ozone and soaking aqueous ammonia pretreatment on the degradation of lignocellulose, monosugars concentration, reducing sugars concentration and biogas production were explored. The results showed that combined ozone and aqueous ammonia pretreatment further increased the delignification ability, improved the saccharification efficiency of rice straw and biogas yield, and enhanced the fiber degradation efficiency. During enzymatic hydrolysis, the glucose concentration was increased first and then decreased with the increase of ozone dosage. When the ozone dosage was 0.75g/g, the glucose concentration was the highest, as 36.92g/L. The longer ammonia pretreatment time was, the higher the reducing sugar concentration was, and the ammonia concentration for 6h ammonia pretreatment was 60.51g/L. Therefore, the suitable combined pretreatment conditions for enzymatic hydrolysis was 0.75g/g ozone dosage and 6h of soaking aqueous ammonia. For biogas fermentation, a high methane yield of 165.39mL/g was obtained with 1.0g/g of ozone dosage and 9h of soaking aqueous ammonia time, which effectively increased the gas production efficiency of rice straw and utilization efficiency of lignocellulosic materials.

Abstract:Corn stover was one of important agricultural residues. Due to Chinese corn farming system, harvesting method, relativity lower mechanism and so on, the corn material for biogas industries was mostly dryyellow corn stover. In order to improve the efficiency of dryyellow corn stover and attain better material for wetstorage, the effect of different wetstorage additives on fermentation performance, bacterial community and biomethane potential (BMP) was focused on. Dryyellow corn stover was stored following five additives treatments for 30d, including Con group (without additives), Glu group (glucose addition of 3%), LP group (glucose addition of 3% and Lactobacillus plantarum addition of 1×106CFU/g), LB group (glucose addition of 3% and Lactobacillus brevis addition of 1×106CFU/g), AA group (glucose addition of 3% and acetic acid addition of 04%). In general, glucose addition 3% prior to storage attained wellpreserve; Lactobacillus plantarum or Lactobacillus brevis addition 1×106CFU/g with glucose addition 3% prior to storage improved the speed of pH value decreasing in early period and water soluble carbohydrate consuming, and significantly higher (P<0.05) lactic acid and acetic acid was produced, respectively. The result of bacterial community from raw material and five treatments showed the most epiphytic bacteria (at the phylum level) was Proteobacteria in raw material, after wetstorage Firmicutes became the dominant flora and Proteobacteria was reduced significantly (P<0.05). The community of lactic acid bacteria showed that Lactobacillus, Enterococcus and Pediococcus were dominant flora when adding glucose alone, and relative abundance of Lactobacillus was increased to 41.07% when adding Lactobacillus plantarum with glucose addition. Weissella became the dominant flora when acetic acid was added. The result of batch test demonstrated that the biomethane potential of dryyellow corn stover was improved by wetstorage with glucose additive. Modified Gompertz models well simulated the anaerobic digestion process of the wetstorage dryyellow corn stover supplemented with additives. Considering the fermentation characteristics, biomethane potential, wetstorage the dryyellow corn stover with glucose addition and acetic acid addition could achieve the well quality and highvalue substance and increase the methane potential yield. 

Abstract:Bacteriocins from lactic acid bacteria (LAB) are ribosomally synthesized peptides or proteins that inhibit or kill the closely related species. Based on the merits of easy degradation by proteases, nonresistance and nontoxic side effects, plantaricin LPL-1 is a promising natural and safe biological preservative for food preservation industry. Aiming at the improvement of plantaricin LPL-1 from Lactobacillus plantarum LPL-1, the inhibitory activity (AU/mL) against Listeria monocytogenes 54002 was used as effect index, and the optimized medium composition was determined by response surface methodology. The major factors were determined as glucose, yeast extract and Tween-80 by single factor tests and Plackett-Burman tests. Based on the results of the steepest grade test and response surface methodology, the optimal medium composition was followed as glucose 208%, yeast extract 051%, tryptone 1.02%, beef extract 1%, Tween-80 1.02mL/L, K2HPO4 3g/L, NaAc 0.5%, MgSO4 0.2g/L, MnSO4 0.3g/L, triammonium citrate 2g/L, and ddH2O 1L. Under the optimal conditions, the inhibitory activity reached up to 75211AU/mL which was increased by 1.62 times. Finally, the research provided insight into the potential use of bacteriocin as a food preservative in the food industry.

Abstract:The enzymeassisted extracted soy emulsion was taken as object to explore the different biological enzyme treatments of emulsion protein structure and stability（Protex 6L, Acalase 24L〖JP〗 lysophospholipase, Phospholipase A2 and Phospholipase D）. It was found that the emulsions were treated with two kinds of proteases and three phospholipases respectively, the particle size distribution, Zeta potential, microscopic observation, infrared spectrum and fluorescence spectrum were known, the results showed that the stratification coefficient and yield of free oil in decreasing trend were lysophospholipase, Acalase 24L, Protex 6L, phospholipase D, and phospholipase A2. Using lysophospholipase hydrolysis, the Zeta potential and the average particle size were increased significantly. The microstructure of the emulsion was found that the oil droplets were accumulated obviously, which was consistent with the results of potential and particle size. The protein secondary structure of the emulsion after the enzyme treatment, the αhelix content was decreased and the random coil content was increased, and αhelix content of the lowest, random coil content was the highest by using lysophospholipase. All samples by protease and phospholipase treatment, the fluorescence intensity was reduced, the fluorescence intensity of the protein was the lowest in the emulsion after lysophospholipase treatment. The content of PA was increased and the PC and PE were decreased by using lysophospholipase, phospholipase A2 and phospholipase D.

Abstract:The change of material mass is an important parameter of material state evaluation during the drying process. Pulsed vacuum drying process is a sealed state, herein, the device of mass measurement must be installed inside the drying chamber, which leads to the measurement processing vulnerable to interference, including the mechanical vibration caused by equipment operation, temperature change caused by drying room heating, airflow interferences which with pulsating state. The multiple effects of these disturbances may cause low measurement accuracy. In order to solve this problem, a measurement plan for separating the heating plate fixed material rack and the material measuring rack was put forward. Firstly, the vibration characteristics of the rack were effectively analyzed. The minimum resonance vibration frequency was about 8Hz, and the main resonance frequency was about 25Hz. According to the vibration characteristic, twoorder IIR digital filter were designed, which effectively solved the vibration problem. Then the drift characteristics of the sensor were measured for zero drift of the sensor caused by temperature. The correction temperature range was 20~45℃, and it was found that it can be corrected by five or six order polynomials. However, the higher calculation of higher order polynomials was not conducive to the realtime control of the whole machine. Therefore, the piecewise polynomial fitting method was adopted. The temperature stage of the piecewise fitting formula of zero drift werey=647062-60410t+1403t2 (20℃≤t<215℃), y=21235-2172t+62t2-065t3 (215℃≤t＜43℃), y=-499406+23206t-2749t2(43℃≤t≤45℃). The air turbulence in the process of inlet and outlet was not regular, which had little effect on the whole drying process. Therefore, the measured data of intake and exhaust stages were removed and replaced with linear interpolation data. In order to get the final mass data, a linear relationship between filtered and corrected sensor output and standard mass was established, and the final mass conversion formula was mo=0.00044021(x-y)-1.4553. In the formula, through the static test, the measurement system of full scale maximum reference error was 0.06%. The results of material drying test showed that the maximum reference error of the drying end was 0.1%. Through the data recording during drying process, it can clearly reflect the quality change and drying rate change in the whole drying process. The research result provided technical support for studying the changing rule of material status and realizing automatic drying process control in the drying process of agricultural products. 

Abstract:A set of high temperature fast drying (HTFD) equipment for hybrid pennisetum was designed to solve the problem that the hybrid pennisetum is difficult to storage due to high moisture content and problem of large artificial labor intensity and large nutrient loss during natural drying. The calculation of key parameters and design of key components were carried out based on the theory of heat and mass transfer. The control unit was designed through mechanical analysis and FLUENT fluid simulation optimization. The drying test of the equipment was conducted and the final moisture content, water activity, color, crude protein and acid washing were used as evaluation indicators. Then the samples were compared with fresh materials and suncured drying samples. The results showed that the final moisture content of hybrid pennisetum dried by HTFD was (16±1.82)%, the water activity was 0.5648 and the productivity was 2.73t/h. L (brightness/darkness) and b (yellowness/blueness) of hybrid pennisetum dried by high temperature fast drying (HTFD) had no significant difference with fresh material, while a (redness/greenness) was increased by 1.43. The crude protein content and the acid detergent fiber (ADF) content had no significant difference, and the crude protein content was decreased by 0.6 percentage point compared with the fresh material. Compared with the suncured drying, the crude protein content of hybrid pennisetum dried by HTFD was increased by 0.63 percentage point, and hybrid pennisetum dried by HTFD had a good apparent quality. The results showed that the set of equipment could meet the drying demand of hybrid pennisetum, which can improve drying yield and the quality of hybrid pennisetum.

Abstract:Agricultural flexible chassis is a kind of vehicle with fourwheel independent steering and four wheel independent driving. There are four special motion modes of this chassis, including straight motion, cross motion, diagonal motion and inplace rotation. Each motion is achieved by controlling the steering stepper motor and the electromagnetic friction lock. For exploring the best controlling parameters of mode switching（MS）, a binary quadratic rotation combination test was conducted by using a selfmade flexible chassis test bench. The speed of the steering stepper motor and the locking voltage of the electromagnetic friction lock were selected as two factors in the test. The entropy method was then used to establish comprehensive evaluation index（CEI） for MS effect integrating the longitudinal force, lateral force, torque of chassis and the angle error of the offcentered arm. Analyses were presented about the influence of two factors on MS effect for the cross motion mode and the inplace rotation mode meanwhile. The regression equation of the CEI and the two factors was also established by DesignExpert 80. The optimal combinations of controlling parameters for these two modes were afterwards obtained by using response surface methodology and finally validated by experiments. The results showed that these two 〖JP3〗factors and their interactions had extremely significant influence on the CEI (P<0.01). The optimal combination of rotation speed and voltage for these two modes was 81r/min, 4.60V and 91r/min, 4.41V, respectively. The maximum relative error between the calculated and experimental values of the CEI was 4.73%. These conclusions can provide references for the study about motion control of agricultural electric chassis.

Abstract:In order to improve the efficiency and movement stability of the high power hydraulic system and reduce the hydraulic impact and energy loss, an electric hydraulic joint valve was designed. The opening and closing of the confluence valve was controlled by the joint control of feedback pressure in the solenoid valve and the reversing valve. The fluid in the valve flowed bidirectional, so the flow speed range was large and the actuator was fast. The valve structure parameters obtained by traditional calculation, throttling groove was designed as U groove, and groove flow area was calculated in Matlab. The AMESim model of the electrohydraulic confluence valve was established and simulated, and the simulation results showed that the flow range of this valve was 0~5.83×10-3m3/s, and the flow rate was stable; in 8~11.5mm spool displacement range, the pressure loss of the confluence valve was decreased with the opening of the valve. When the spool displacement was 11.5mm, the pressure loss of the confluence valve was only 0.18MPa, and the energy loss was small. The test results of the hoisting system of crane showed that the maximum flow rate of the valve was 6×10-3m3/s, and the pressure loss at the maximum flow rate was 0.27MPa. In single pump mode when the hoist was lifted, the minimum stable fretting speed of the reel was 1.9r/min, the starting impact was 2.1MPa, the stop impact was 2.2MPa, the starting delay was 0.7s, and the stop delay was 0.8s; when the hoist was fallen, the minimum stable fretting speed of the reel was 2.17r/min, the starting impact was 5.2MPa, the stop impact was 1.9MPa, the starting delay was 1.1s, and the stop delay was 0.75s. In double pump mode when the hoist was lifted, the minimum stable fretting speed of the reel was 2.17r/min, the starting impact was 2.5MPa, the stop impact was zero, the starting delay was 0.65s, and the stop delay was 0.28s; when the hoist was fallen, the minimum stable fretting speed of the reel was 1.57r/min, the starting impact 〖JP2〗was 2.7MPa, the stop impact was 1.6MPa, the starting delay was 0.57s, and the stop delay was 0.31s.

Abstract:The aim was to propose a combined position/force control scheme for Stewart parallel platform’s interacting tasks with environment or human body based on force sensor and vision system. The vision system included a high resolution camera and a laser range finder which aimed at providing global position information. To enhance the performance of industrial tasks interacting with the environment, a novel hybrid position/force control algorithm using exteroceptive vision system for hydraulic Stewart parallel platform was proposed. A two controlloop scheme was designed for interacting tasks, and gravity compensation was demonstrated to balance the disturbance. A full experimental system was built and a number of experiments were performed. The whole experimental system consisted of two parts, which was the hydraulic parallel manipulator and the docking simulation system. Firstly, a relative position tracking experiment was conducted to investigate the manipulator’s highspeed tracking ability. Movement commands of ±100mm/s in y axis and ±80mm/s in z axis were given to actuate the manipulator. From the experiment result, the relative position tracking errors of y and z axes were both smaller than 10mm. And then the dynamic docking experiment was performed to investigate the interacting performance with the target object of the proposed combined position/force control law, where the movement speeds of the docking simulator was driven along the y axis at 50mm/s and z axis at 40mm/s. In dynamic docking experiment, the contact force of the manipulator was controlled within 300N, the hydraulic manipulator could track and dock with the moving target reliably and quickly. The above two experiments were conducted and the experiment results demonstrated the effectiveness and stability of the proposed algorithm.

Abstract:A solution region design method based on planar sixbar mechanisms for robotic fingers was proposed to achieve the goal of obtaining diversified fingers with different dimensions. An infinite number of solutions of planar sixbar mechanisms can be obtained by predefining four moving positions, and all these solutions can be expressed on a planar region, which was called the solution region. Firstly, the planar sixbar mechanisms had five moving links, and three of them simulated the proximal, middle and the distal knuckle of human fingers, respectively. Four moving positions of the three links, which expressed the bending motion of a finger, were predefined. The coordinates of unknown joints, which were located inside the finger, were limited to restrict them in the kunckle. According to the theory of motion generation in four moving positions of planar sixbar mechanisms, the solution curves and feasible segments of the known joints were obtained. After segmenting the feasible segments, a solution region of planar sixbar mechanisms, expressed by the coordinates of two joints, was established. The parameter K, an index that measured the force transmission property of a mechanism, was introduced to filter the feasible segments. Then a feasible solution region was obtained, and the distribution law of K on the feasible solution region was analyzed. Finally, A planar sixbar mechanism was selected on the feasible solution region to design a finger prototype. The new feasible solution region expressed actual coordinates of the joints, and showed the force transmission property of planer sixbar mechanisms directly, which contributed to the selection of mechanisms that satisfied all the requirements. Each point on the feasible solution region was a planar sixbar mechanism. Therefore, appropriate planar sixbar mechanisms can be selected on the solution region according to different design objectives, such as anthropomorphic fingers, rehabitation fingers. And the prototype proved the validity and availability of the solution region design method for robotic fingers design.

Abstract:During the process of dynamic analysis of the robot, the researchers generally ignored or not fully considered the effect of joint frictions on the dynamic model of the robot. Although the process of mathematical deduction was simplified, the model was quite different from the practice. Taking a 3-RPS parallel robot of which the rotation axes were parallel arranged as the research object, a dynamic modeling method based on modified Lagrange operator was presented. Firstly, the DOF of the moving platform was studied based on the screw theory and the kinematics model of the system was established by vector method. By analyzing the kinetic energy and potential energy of the whole moving components, the ideal dynamic model of the parallel robot was set up based on Lagrange equations. After that, taking the single chain, telescopic rod and moving platform as the research objects, the constraining forces of all motion joints were solved based on the D′ Alemberts principle, the joint frictions were regarded as the nonconservative forces of the system, based on the ‘Coulomb+viscous’ friction model, the work done by joint frictions was disposed accurately and quantitatively. Finally, the work done by joint frictions was always negative, some mechanical energy of the parallel robot was converted to other forms of energy and the mechanical energy of the system was reduced. Based on the ideal Lagrange operator，the Lagrange operator was amended based on the form of negative work done by frictions, and the system dynamic model considering all joint frictions was established. At the same time, the dynamic models with and without considering joint frictions were simulated and contrasted. In a simulation cycle, the results showed that the relative errors of the first, second and third driving forces were 18.1%, 12.6% and 16.5%, the results provided a theoretical basis for the frictional compensation of the robot control system and the analysis process also had reference significance for other parallel robots performance analysis and optimization.

Abstract:The magnetorheological damper (MR damper) is a kind of vibration control device with excellent performance, which is used in construction machinery, vehicle, bridge and other fields widely. The MR damper is a complex system of multi field coupling at work, expressing accurately its mechanical properties with mathematical analytical equations is very difficult. In order to accurately predict the dynamic performance of the MR damper under temperature effect, a parameterized simulation modeling method was proposed. A nonlinear physical parameter equation related to the viscosity temperature characteristics was established by using the measured data fitting method of the magnetorheological fluid test. Based on the Bingham mechanical model and the influence analysis of temperature effect, the ANSYS UDF programs were compiled, the model parameters were set up, and the parametric simulation modeling was carried out. The viscous damping forces were solved by using the Fluent module, and the coulomb damping forces were solved by using Emag module. A mechanical testing platform for MR dampers under temperature effect was built, and the simulation models were modified, compared and verified through experiments, and the variation laws of damping force and energy dissipation at different temperatures were discussed. The results showed that the temperature effect mainly affected the viscous damping force; the simulation results were highly consistent with the measured values. The energy dissipation of dampers at different temperatures and currents was inversely proportional to the temperature and proportional to the coulomb damping force. The simulation modeling method can predict the characteristics of the output damping force, and can be used to carry out the structure design and parameter optimization of the MR damper.

Abstract:According to the principle of Wankel engine transmission, a double inlet and outlet triangular rotor pump was designed, and the working principle, structural characteristics and mathematical model of cylinder line of the triangular rotor pump were described. Mathematical model of mechanical losses of the new pump such as seals loss, rotor end loss, bearings loss and gear meshing loss was built. The working fluid in the pump was numerically simulated by using Fluent. The results of numerical simulation and mathematical model were used to calculate and analyze the flow rate, pressure, mechanical loss and mechanical efficiency of the triangular rotor pump, and the results of numerical simulation were verified by experiments. The results showed that at a rated speed of 190r/min, the inlet flow rate was fluctuated, and the three working chambers alternately performed suction and discharge, and the total outlet flow was relatively stable. The pressure cycle of one work cycle of the working chamber included four phases of the working chamber expansion phase, the rapid pressurization phase, the stable output phase, and the rapid depressurization phase. The flow rate and pressure recorded in the experiment agreed well with the predicted values. With the increase of the rotational speed, the pressure and flow rate were significantly 〖JP3〗increased. The predicted values of the flow rate and pressure at the rated rotational speed were 8.96m3/h and 2013.92kPa, respectively. The friction loss of the seals, rotor end, bearings, and gear meshing at the rated rotational speed obtained by the mathematical model of mechanical loss were 103.4W, 182.5W, 60.5W and 33.2W, respectively, and the predicted and experimental values of mechanical efficiency were in good agreement, which were 92.9% and 93.3%, respectively.

Abstract:A compact giant magnetostrictive actuator with bowtype amplifier structure was designed to meet the driving needs of largeflow electrohydraulic servo valve. Based on mechanics and vibration theory, the static and dynamic models of this structure were established. The influence of the dimensional parameters towards its static and dynamic performance was analyzed, and it was concluded that its static and dynamic properties were mutually restrictive. Combining with the application requirements of giant magnetostrictive actuator in electrohydraulic servo valve, the multiobjective optimization design was conducted for the bowtype structure, and then the static and dynamic models were validated by the finite element analysis. Finally, the giant magnetostrictive actuator with bowtype displacement amplifier structure was prototyped to test its static and dynamic properties. The results showed that the amplification ratio of this structure was fluctuated from 8.13 to 8.72, the maximum output displacement was 107.9μm, and the natural frequency reached 168Hz. The results were basically in consistent with the theoretical models. Compared with the performance before optimization, the natural frequency was increased by 55.6% when the requirement of the static magnification was met. The actuator designed can basically meet the driving requirements of servo valve, which proved that the optimized design method was effective.

Abstract:Unmanned ocean detector, as an important tool for the development of marine resources, generally lacks efficient and reliable power supply. Wave energy is the most widely distributed renewable ocean energy, and it is expected to be the ideal energy source for the detectors. A novel wave energy point absorber was presented based on the counterrotating selfadaptable mechanism. The new point absorber can achieve the selfadaptable deflection of the blades to the water flow and automatically balance the overall torque of the absorber. A comprehensive numerical analysis and experimental verification of the new point absorber were conducted, and the influence rules of structure and system parameters on the power and efficiency characteristics were obtained. Through numerical analysis, it was found that the power and efficiency characteristics of the point absorber were greatly affected by the inclination angle of the blade, the relative flow velocity, the rotational speed and the interaction between the upper and lower absorbers. The highvalue range of power of the absorber was in the high relative velocity range, and the corresponding optimal blade inclination angle was 30°~45°; the highvalue range of efficiency was in the low relative velocity range, and the corresponding optimal blade inclination angle was 20°~35°. A rotational speed of 50~90r/min was suitable for most typical sea conditions. Large blade inclination angle can weaken the interaction between the upper and lower absorbers, and small blade inclination angle can improve the performance of the singlelayer absorber. Selecting suitable structure and system parameters can help further optimize the performance characteristics of the novel point absorber. In addition, validation experiments in test pool and wave tank were conducted respectively to verify the accuracy of numerical analysis and the feasibility of the novel point absorber.

Abstract:Research and development of machinery and equipment focus on innovation of individual components and part of core technology, designers need to consult the manual again and again, and a lot of repetitive work was done. With the rapid development of computer technology, some simple parts libraries, standard parts libraries and part libraries are generated, but these libraries just can realize simple resource collection and original copy, personalized design and development capabilities cannot be provided. Virtual assembly technology is the important link in the process of complex mechanical equipment research and development, and how to realize intelligent and automated virtual assembly is regarded as an important way to improve efficiency of research and development. Establishment of standardized digital model resources and database was required, which was used as model base and information sources to realize intelligent virtual assembly technology. Aiming at the standardized construction of digital model of complex mechanical equipment, digital model holographic identification system based on the matterelement was put forward, and auxiliary identification method was given. Complex mechanical equipment was studied, its topology hierarchy was researched, the basic information of parts and assembly information was analyzed, the composition of basic and assembly matterelement was defined, the semantic information coding and identification rules of matterelement were enacted, creation of assembly reference elements and construction of digital holographic model identification system was completed. Auxiliary identification method of digital model identification was researched in order to achieve efficient and intelligent identification, and a humancomputer interaction platform which was suitable for holographic system was designed. The platform can achieve the functions of rapid extraction and interpret assembly information, assembly related information can be converted to matterelement code, and automatic identification, intelligently auxiliary model identification was completed and assembly reference element was created. Test results showed that digital holographic model identification system and auxiliary identification method was feasible and effective, quick and effective identification method was provided for designers. It also set the base for complex mechanical equipment digital design system which combined with professional knowledge.