Abstract:The swine industry is the pillar industry of animal husbandry in China. With the development of national economy and the scale farming, the demand for engineering technology of swine facilities is increasing in China. In order to provide reference and support for the development of swine farming, the research and application of key facilities engineering technology in swine farming were summarized and analyzed. The research and development of pig houses, piglet breading facilities, feeders and manure disposal facilities were mainly analyzed. At present, the engineering technology system for swine facilities and equipment was established in China, which can meet the demand of swine farming in China, but there was still a certain gap compared with the engineering technology of swine facilities in developed countries in animal husbandry, the development of various links in swine facilities engineering was not balanced, and the technical level of mechanization, automation and intellectualization of the facilities engineering was low. The basic researching system of key facilities engineering technology was not perfect, the matching of swine facilities was poor, and the applicability and reliability of swine farming equipment was low. Establishing a perfect researching system for the engineering technology of swine facilities, and strengthening the integration and cooperation of breeding, feed, facilities, resources and environment, and then boosting the research and development of swine facilities and equipment suitable for the supporting applications in the North and South China, so as to realize the health/welfare, ecology, automation and intellectualization of the swine farming process, which would be the development trend of swine facilities engineering technology in China.

Abstract:For the purpose of overcoming the obstacles in application of autonomous rice drill seeder in paddy fields, a path tracking algorithm with high accuracy used for steering control during straight traveling in uneven mud paddy fields was introduced. Combining lateral deviation and heading angle deviation as feedback, a nonlinear steering control model was developed in the algorithm. Integrators were added to the nonlinear control model to eliminate the steadystate errors. Moreover, the velocity of vehicle was also taken into account in the model to improve the path tracking accuracy of the algorithm. To avoid the position error caused by incline, the influence caused by the roll angle and the pitch angle of the vehicle on position coordinates given by GPS were taken into account when the vehicle was on a slant. The algorithm about turn control at the edge of the field was introduced. The overall control scheme was implemented and the experiments carried out in arable paddy fields showed that the mean absolute lateral deviation of the algorithm was 0.027m and the mean heading angle deviation was 0027°. The path tracking algorithm was able to meet the required precision for autonomous rice drill seeder in paddy fields of China.

Abstract:In order to detect the mango yield on trees rapidly, a green mango visual detection method based on unmanned aerial vehicle (UAV) was proposed. The deep learning technology and the YOLOv2 model were adopted to detect the mango images captured by UAV. Firstly, totally 471 images of the mango on trees were collected by the UAV. To meet the demand of diversity, totally 360 images included different shooting distances and different lighting situations were selected. Among which, 300 images were selected randomly as the training set, the other 60 images were used as the test set. Also, the shooting plan of the whole tree was designed. By image collecting and image mosaic, the integrated images of five mango trees were worked out for the yield estimating experiment of mango. After image collection, these images were marked manually and used to build the training set and the test set. The batch size and the initial learning rate were determined by experiments. During the model training, the learning rate was reduced gradually as the training times were changed. The mean average precision (MAP) of the trained model on the training set was 86.43%. By designing the experiments, the accuracy of mango recognition with images that containing different fruit numbers and different lighting conditions was worked out. Also, the yield estimation experiment was designed. The experimental results showed that the average running time of an image using the given algorithm was 0.08s, while the accuracy of the teat set was 90.64% and the false recognition rate was 9.36%; the highest recognition accuracy of image with different numbers of fruits was 94.55% and the lowest was 88.05%. The recognition accuracy was 93.42% under the condition of direct sunlight, and the recognition accuracy was 87.18% under the condition of backlight. The average error of the yield estimation of mango tree was 12.79%. The result demonstrated that the algorithm was effective for mango in natural environment, which can provide technical support for estimating the yield of fruits and vegetables in intelligent agricultural production.

Abstract:Corn is one of the main grain crops in China and its production accounts for more than 20% of the World’s corn production. Weed is one of the most important factors influencing maize yield. Effective recognition method of cron and weed can improve corn quality and production accounts. At present, pesticide spraying is the main way of removing weed in China. Excessive spraying of pesticides brings problems such as environmental pollution and food safety, and therefore precise spraying is the key of weeding to reduce the amount of pesticides and increase the utilization of pesticides. Precise application of pesticides is based on accurate identification of weeds, researchers at home and abroad have done a lot of research. Most existing weed identification methods rely on manually selected weed features, such as shape, texture, etc., which takes longer time to identify the image, and the accuracy of identification still needs further improvement. The deep learning method was used to achieve automatic extraction of weed image features without relying on artificial feature screening, and combined the binary Hash code to compress high-dimensional weed feature data to achieve rapid weed identification and provide information support for subsequent field drug spraying. In order to improve accuracy of crop and weed identification, combining with the strong feature extraction capabilities of the deep convolutional network and the ease of storage and fast retrieval of the Hash code, a fast field weed identification method was proposed based on the deep convolutional network and binary Hash code. A pretrained multilayer convolutional neural network was used to construct a weed identification model with a binary Hash layer, and the model was fine-tuned with the collected weed data set. The binary Hash layer proposed could effectively compress the highdimensional weed image features to facilitate the storage and subsequent calculation of the highdimensional weed image features. During tests of weed identification, the trained model was used to extract the fullconnection layer feature codes and binary Hash codes of the input image, and then compared with the fullconnection layer feature codes and binary Hash codes stored in the database to calculate the Hamming distance and the Euclidean distance. After that, the most similar K images could be found out according to last step’s results. Finally, the labels’ frequency of the K images was counted and the original image was classified into the highest frequency category of label to achieve the purpose of weed identification. The effects of different layers of convolutional networks and different length binary Hash code on weed identification were compared, and finally the weed identification model was determined, which included four layers convolutional neural network and 128bit binary Hash code. The experimental results showed that the method proposed could achieve 98.6% accuracy in field weed identification, and the loss function stability was improved compared with the ordinary model. At the same time, it also performed well on other weeds datasets with an accuracy of 95.8%, which meant that the proposed method was universal. The research results could provide reference for precision weeding. The experiment carried out in corn field showed that the method could achieve 92.7% accuracy, and it could effectively reduce pesticide waste which was suitable for precision spray.

Abstract:Collecting airborne urediniospores of Puccinia striiformis f. sp. tritici (Pst) in wheat fields using spore trap devices has currently become an important approach for devising strategies early and effectively controlling wheat stripe rust. However, the existing spore trap devices have some shortcomings, such as low efficiency, timeconsuming and requiring manual replacement of slides or plastic tapes. To this end, a highmagnification and highresolution microimage remote acquisition system of uredinispores of Puccinia striiformis f. sp. tritici was designed and manufactured based on ARK-1123C embedded industrial computer and microscope CCD digital camera. The hardware and software architectures of the microimage remote acquisition system were designed, which realized a series of functions, including automatic supply of slide, coating a thin film of petroleum jelly, aerial urediniospore capture, urediniospore microimage acquisition, and slide recycling. Besides, the parameters of urediniospore capture and microimage acquisition could be set remotely according to user’s requirement, and the collected images could be transmitted to the remote server by 4G wireless network. In order to verify the performance of the system, the system was deployed and tested in a wheat field for 40 d. Experimental results showed that the system worked stably for a long time, which could capture the microimages of uredinispores, with 400 times magnification and 4096 pixels×3288 pixels resolution. The experiments validated that the proposed remote acquisition system can automatically collect and remotely transmit the microscopic image of uredinispores in real time, which provided important technical support for the automatic counting of the airborne uredinispores and the prediction of the wheat stripe rust in the field. It can also provide a reference for monitoring other airborne fungal spores.

Abstract:In order to solve the problem of large amount of DEM-CFD calculation, the Fluent simulation was firstly used and threefactor threelevel orthogonal test of the position of the air inlet was designed. The mean of pressure in seed filling area holes, mean of pressure in self cleared area holes, mean of pressure in clearing seed area and pressure of other holes were taken. The mean value was the evaluation index, the range and variance analysis were carried out to determine the optimum inlet location parameters. Secondly, the Bonding model of corn grain adhesive particles was established. The structure grid of the airways flow field was divided and the relevant parameters were set up to realize the DEM-CFD gas solid coupling simulation of corn gas suction seed metering device. The pressure of the plate holes was extracted from the flow field when the corn seeds adsorbed. It was concluded that the pressure changes in each region were stable, and the pressure ranges from large to small was filling area, self cleaning area, clear seed area, seed carrying area and seed unloading area. Through theoretical calculation, the minimum pressure of adsorption was obtained, which was compared with the results obtained by simulation. The results showed that the simulation results were higher than the theoretical calculation of the minimum adsorption pressure. The first generation of conventional chamber structure seed metering device and the designed seed metering device were used to test and analyze the air pressure, which verified the rationality of the selected inlet position parameters. Finally, by changing the speed of the plate, the common operating speed of the seed metering device was 8km/h, 10km/h, 12km/h and 14km/h, and the qualified index, multiple index and missing index were used to evaluate the performance of seed metering performance under different conditions by simulation test, and the comparison was carried out through the bench test. The results showed that in the simulation test, when the operation speed was not more than 14km/h and the negative pressure was 3kPa, the qualified index was not less than 89.7%, the missing index was less than 7.8% and the multiple index was less than 2.5%. In the bench test, under the same operating speed and negative pressure value, the seed spacing qualified index can reach 90.3%, the multiple index was less than 2.7%, and the missing index was less than 7%. The simulation test was close to the bench test, which verified the feasibility of the simulation.

Abstract:In order to adjust to the requirement of hill seeding for pneumatic centralized metering device for hybrid rice, a seed hill feeding device was designed to supply quantitative seeds. According to the mechanical and physical properties of rice seeds and agronomic requirement of hill seeding, the involutetype modelhole was introduced. The main structural parameters of the seed hill feeding device were determined and the mechanical models of seed filling and throwing processes were established. The effects of varieties of rice seeds, number of involutetype feeding unit and rotational speed on seed feeding and hillforming performance were carried out in bench test. The results showed that when the number of involutetype feeding unit was 3~8 and rotational speed was 10~40r/min, the seed quantity was increased with the increase of number of involutetype feeding unit and rotational speed. The range of seed quantity was 2392~17732 grains per minute. The variation coefficient of seed quantity was less than 10% for the rotational speed of 20~40r/min. The seed hill feeding device could be applied in different varieties of rice seeds, but the seed quantity was affected by the length and bulk density of rice seed. The seed quantity per hill was increased with the increase of number of involutetype feeding unit, and decreased with the decrease of rotational speed. The optimum rotational speed which resulted in the variation coefficient of seed quantity per hill less than 25.0% was 20~30r/min. The seed quantity per hill was 19~38 grains. The hill diameter was increased with the increase of number of involutetype feeding unit and rotational speed. The seed spacing was stable for different treatments. The field experiments indicated that the hill seeding could be realized by using the seed hill feeding device. The average seedlings and seed spacing were 3.07 seedlings per hill and 180.2mm, respectively, which met the agronomic requirements of rice directseeding. The results can provide basis for structural design of pneumatic centralized metering device and hill seeding for hybrid rice.

Abstract:The stubble clearance efficiency of instrument is an important indicator of notillage seeding under the mode of protective farming mode. Based on the conservation tillage model in Northeast China, a straw cleaning mechanism with concave structure was designed and improved on the 2BMZF-2 notill planter produced by Jilin Kangda Agricultural Machinery Co., Ltd. In addition, factors such as the operating speed of planter in the stubble clearance mechanism, the soil contacting depth of stubble clearance wheel and the movement declination angle of stubble clearance wheel were analyzed. The key parameters of stubble clearance mechanism were identified according to the simulation analysis and the analysis on the results of field trial, which can be listed as follows: the diameter of stubble clearance wheel disc was 350mm, the angle between the movement direction of the stubble clearance wheel and the working direction of notillage planter was 37.5°, and the soil contacting depth was 70mm. The result of the experiment indicated that the stubble clearance rate could reach up to as high as 8361% at the operating speed of 2.77m/s. The stubble clearance mechanism designed could effectively clean the seedbed and prevent the blocking of instrument, which, in the meantime, was suitable for the uniform ridge farming mode of maize as well as the wide and narrow row farming mode of maize.

Abstract:As one of the core working parts of automatic transplanter, the planting mechanism directly determines the effect of transplanting seedlings. The problem of different plant spacings of different crops was focused on. With the selfmade planting mechanism with planetary gears as the research object, the composition and working principle of the planting mechanism were clarified. On this basis, a theoretical model of the planting mechanism was constructed, and the mathematical model of the trajectory about the planting points on front and back duckbills were analyzed and established. The mathematical model was programmed by using Matlab to establish its analysis program. Computeraided optimization of humancomputer interaction interface was developed based on the Matlab GUI platform. With the aid of the optimized design interface, the mathematical model of the trajectory on planting points was solved to simulate the trajectory curve of the planting points on front and back duckbills. The effects of changes in the main parameters of the planting mechanism such as the rotation radius of planet frame, the length of the duckbill, the angle between the initial position of the duckbill and the horizontal line, and the distance from the end point of duckbill to the center of the rotation on the trajectory of the planting site were analyzed. With the value of characteristic parameter λ being greater than 1, the height of the buckle on the planting section being greater than the height of the pot seedling, the front and back duckbills without dragging and hanging seedlings, the size of the hole formed by duckbills on the ridge surface being relatively small and other conditions as optimization goals, through simulation analysis on the influence of main parameters of planting mechanism on trajectory of planting points, institutional parameters that can meet the planting requirements of 280mm, 310mm and 345mm at the same time were obtained and the planting trajectory of parameter combination was verified under three planting distances by simulation. The cucumber seedlings cultivated by 72hole plug trays were selected as the test objects. With the variation coefficient and planting verticality as the evaluation index, prototype performance tests were conducted on the optimized mechanical parameters. The results showed that the excellent rate of planting verticality on three plant distances was higher than 81%, the total passing rate was over 94.8%, and the variation coefficient of spacing distances was less than 3.2%. This proved that the optimized design of the planting mechanism with planetary gears had good transplanting performance, which can meet the requirements for transplanting of multiple planting distances, and verified the correctness and feasibility of theoretical models and optimization methods. The research results provided an effective method for transplanter design.

Abstract:Due to the problem of low rate of garlic bulbil with upward direction after mechanical sowing in China recently, the physical and geometric parameters of Cangshan garlic were measured, and the discrete element method was used. The dynamics model of mechanism with double duck bill shape adjusting the direction of the garlic bulbil was established. The movement law of garlic in three kinds of garlic adjusting mechanism and different factors’ influences on the rate of garlic bulbil with upward direction were studied, such as the different curves of duck bill, gravity of garlics, speed of seeding and the secondary bouncing of garlics. Besides, the principle of adjusting the garlics to upward direction was also studied. The indoor planting testbed and the field prototype were manufactured. The seeding experiment was carried out, and the dynamic images of garlics’ movement at one point were recorded by visual method. It was found that the result was consistent with the simulation process, and the deviation between the rate of garlic bulbil with upward direction of the experiment and that of the simulation was less than 5%. The results showed that it was effective to use the discrete element method to analyze the movement of garlics during sowing. The rate of garlic bulbil with upward direction of the test in field can be up to 95.67%, which was increased by 4.67 percentage points.

Abstract:Holefertilizing technology can be used for fixedpoint, quantitative and accurate fertilization while seeding is in operation, which is an effective method to improve the fertilizer use efficiency of corn, soybean and other crops. During the fertilizer transfer process of the holefertilizing apparatus, the rigid contact of fertilizer plate with fertilizer protection cavity caused the phenomenon of fertilizer blocking, which seriously affected the stability of fertilizer delivery. Thus a flexible fertilizer protection method was put forward and a flexible fertilizer protection mechanism was designed by using the nylon fiber which was in the shape of plum flowers. The theoretical calculation and finite element analysis of the mechanical property of single nylon fiber was carried out, the effect of the structural parameters of nylon fiber on the stress was obtained and the diameter of the selected fiber was determined as 0.1mm. The analysis of fiber bundle structure showed that the fiber length should be 13mm and the mounting hole diameter should be 4mm, to ensure the safe distance of mounting hole and reasonable clearance of brush bundle. EDEM software was used to simulate the stress changes of each wall during the process of fertilizer group compressed in fertilizer cavity, the negative clearance between fertilizer plate and bottom fertilizer protection brush was designed as 1.6mm and 0.5mm with side fertilizer protection brush. Flexible fertilizer protection mechanism was designed and the test results showed that there was no fertilizer blocking problem, the rotary torque of the fertilizer plate was 4.71N·m which was reduced by 58.54% compared with the original mechanism without flexible fertilizer protection mechanism. This mechanism could effectively avoid the fertilizer blocking problem, reduce the resistance of fertilizer delivery and insure the stability of the fertilizer delivery. The research result might provide a new approach for precise fertilizer delivery.

Abstract:Aiming at the inaccuracy of fertilizer location in potato planter popularized in China, combined with the distribution law of potato root system and the planting pattern characteristics of one ridge two rows for potato, and the separated layer fertilization technology based on surface drainage and V type anti blocking structure was proposed. The design and analysis of separated layer fertilization furrow opener and a depth adjustable separated layer fertilization furrow opener was developed. The motion relationship between the soil and furrow opener was studied, and the movement process of fertilizer on curved surface fertilizing plate was analyzed. The variation coefficient of the stability of the lower layer was experimented by single factor bench test, and the optimum working length of groove wheel was 50mm. Under the condition of optimum working length of groove wheel, the quadratic universal rotary assembly experiment of two factors were carried out with the rotation speed of manure shaft and the curved surface angle of fertilizing plate as experimental factors, the variation coefficient of the stability of left and right sides for upper layer fertilizing box as experimental index. The saliency analysis of regression equation and parameter optimization were obtained by using the DPS and Matlab software. The results showed that the rotation speed of fertilizing shaft of 20.5r/min and the curved surface angle of fertilizing plate of 15° were the best combination factors, which led to the variation coefficient of the stability of left and right sides for upper layer fertilizing box of 3.30%. Five repeated experiments were carried out under the optimal parameters. The results showed that the average variation coefficient of the stability of left and right sides for upper layer fertilizing box was 3.71%, and the experimental value was similar to that of the theoretical value. Meanwhile, the field performance experiment showed that the performance of separated layer fertilization furrow opener completely met the relevant standards of potato planting.

Abstract:For the repression of hilly area in Northeast China, the soil moisture content of different topography is different and the topography varies greatly. To achieve better repression effect, the corresponding load and forward speed need to be matched. In order to find the optimal level combination of rigid crushing wheel operation in hilly areas, velocity variables were firstly added to establish a dynamic repression and soil mechanism model based on quasistatic principle of repressive and soil mechanism model, and seek soil moisture content, load and advancement. The relationship between speed and soil subsidence and working resistance was then obtained based on SPH algorithm to construct a threedimensional simulation model of rigid repression wheel and soil in LS-DYNA software to simulate the dynamic process of interaction between rigid repressing wheel and soil. The numerical simulation method was combined with the central surface composite response test scheme to carry out the simulation test. The mathematical regression model of soil water content, load, forward speed, soil subsidence and working resistance was obtained by simulation test. On this basis, the R language was used. The ant colony algorithm performed multiobjective optimization on the mathematical regression model to obtain the Pareto optimal solution set, and the water contents of（12±0.1）%,（14±0.1）%,（16±0.1）%,（18±0.1）% and （20±0.1）% were selected to find the five optimal solutions. The soil trough test was carried out to verify the optimal solution. The error between the test result and prediction result was less than 12%, which indicated the reliability of test optimization result and also verified the feasibility of simulation. The research result can provide theoretical and data basis for the research of planter and supporting technology in hilly area.

Abstract:With the increase of planting area of safflower in Xinjiang, problems such as low efficiency of artificial picking, high labor intensity and serious filaments residue are becoming increasingly prominent. The development of safflower industrialization is seriously restricted, so it is urgent to realize mechanized picking of safflower. The clamping combtype picking device was developed. The motion attitude of safflower had an important influence on picking effect, in order to reveal the relationship between different structure parameters and motion parameters of picking device and safflower movement, a combpicking model was established based on the material characteristics of safflower. The picking process was simulated by ANSYS/LS-DYNA software, and the structure and motion parameters of the picking device were adjusted continuously until the safflower ball and branch reached the ideal picking position. The simulation results showed that the movement of safflower balls and branches picked in low position was more stable than that in high position, and picking device can realize ideal picking. When walking velocity was 2.5km/h，rotation velocity was 150r/min，and the horizontal distance between the limit rod and the rotating center of comb teeth was 30mm, the picking effect was the best. According to the field picking requirements of safflower, the experiment platform was built and the picking experiment was carried out. The result of picking test showed that 56% of safflower can realize ideal picking and average recovery rate was 48.5%. The results provided a theoretical basis for the parameter optimization design of combed safflower picking device.

Abstract:In order to improve the efficiency of castor shelling, the method of tumbling shelling was determined, and the shelling device with double curved table structure was designed. The cleaning mechanism combined vibration screening and air suction was designed. Depending on the physical and mechanical properties of the castor fruit, the asymmetrical double circular table structure of the inner shell of husking device was designed. The taper angle was determined and the outer shell of the shelling drum was designed, the mathematical model of the position of the shelling drum and the shelling gap at different stages was established, and a theoretical basis was provided for the dynamic simulation of the shelling device; the ADAMS was used to extract the nettle. The kinematics simulation was carried out in different shelling stages to analyze the variation of the displacement and velocity of the material in the fracturing stage and the shelling stage, and analyze the influence of gap of discharge port of different unloading drums on each stage. The simulation results showed that in the fracturing stage, with the increase of gap of discharge port of upper shelling drum, the time after castor fruit reached the specific fracturing position was delayed, the displacement was increased, the speed of movement reached the maximum at 056s. In the shelling stage, with the increase of gap of discharge port of lower shelling drum, the time when the castor seed reached the specific shelling position was delayed; when the castor seed reached the shell breaking condition, the displacement was increased, and the moving speed was firstly increased and then decreased. According to the ADAMS simulation results, the reasonable working parameter interval of the adjustable castor shelling and clearing device was selected, taking the speed of the shelling drum, the gap of the upper shelling drum outlet and the gap of the lower shelling drum outlet as the factors. The response surface analysis method was used to test the sealing device. After double target optimization, the rotation speed of the drum was 270r/min, the gap of discharge port of upper shelling drum was 13.54mm, and the gap of outlet of lower shelling drum was 5mm. The test result showed that the performance of the sealing device was the best. The removal rate was 92.03% and the breakage rate was 3.1%.

Abstract:The microorganism fermented feed can improve the production performance, enhance immunity and improve meat quality in pigs, and the production of fermented feed is solidstate fermentation in domestic. In order to produce fermented feed in feeding field and automatic feeding, an automatic fermenting and feeding equipment was designed. The equipment was composed of feed fermentation system, PLC and PIC MCU control system and feeding system. The complete diet mixed with bacterial liquid was placed in the hopper, and conveyed to the transverse screw conveyor through the metering grooved wheel under the hopper, and then conveyed to the fermentor by a longitudinal screw conveyor. In the screw conveyors, bacteria and feed were fully mixed. The fermentor was designed with 100L in volume and 7 in number, which can ensure punctual feeding for different breeding objects. When fermentation was over，feed was layout from the fermentor to the feeding vehicle automatically, and then discharged into different trough quantitatively. The PLC system and the PIC MCU system constituted the control system, and wireless communication was used between them. The operator only needed to pour the feed to be fermented into the hopper, and then set the parameters of the fermentation time, the volume of the feed and the feeding object in the humancomputer interface. This equipment would automatically accomplish the whole process from fermentation to feeding. The test result showed that the volume errors of screw conveyors and feeding vehicle were both less than 6%; the positioning error of feeding vehicle to the troughs was less than 11.75mm; the parameters included fermentation time, feeding object and feeding vehicle speed were controlled accurately. The equipment worked stable and reliable, which can reduce labor intensity significantly and meet the requirements of solidstate fermented feed production and feeding in feeding field.

Abstract:In order to study the influence of airfoil camber on the hydraulic performance of the axialflow pump, the methods of numerical simulation and model test were adopted to do the research. The position and height of the maximum camber of the airfoil were changed to maintain the similar lift coefficient. Based on the parametric airfoil, different airfoils with different airfoil cambers were designed. The corresponding axialflow impellers on the hydraulic characteristics were analyzed. Firstly, the airfoil optimization method was adopted for the maximum camber position of the twodimensional airfoil at 0.3L~0.65L, which ensured that the lift coefficient of the airfoil was basically the same. So the airfoil design schemes with different maximum airfoil degrees were obtained. Secondly, the twodimensional cascade theory was used to design the axial flow pump impeller based on the three designed airfoil schemes of the maximum airfoil camber position of 0.4L, 0.5L and 0.6L. The rest of the design parameters remained unchanged, and the three different axialflow impellers were obtained. The matching guide vane, elbow and impeller were combined into a pump section for numerical simulation calculation. Finally, the reliability of the numerical calculation results was verified by the pump section model test. The research results showed that in order to ensure better energy and cavitation performance of the axialflow pump, the maximum airfoil camber position was preferably selected as 0.4L~0.6L. When the maximum airfoil camber position was 0.5L, the pump had a wide range of highefficiency area, and the flowhead curve was relatively smooth. In the large flow area, as the maximum airfoil camber position was closer to the airfoil trailing edge, the cavitation and the energy performance of the pump would increase. The research had important theoretical significance and guiding significance in the design of axialflow pump and practical engineering application.

Abstract:Soil moisture content (SMC) is one of the most critical soil components for successful plant growth and land management, particularly in arid and semiarid areas. In existing researches, it was determined by a conventional method based on oven drying of samples collected from fields. The first derivative (FD), absorbance (Abs) and continuumremoval (CR) algorithm were brought into the preprocessing of hyperspectral data based on the initial Savitzky-Golay (SG) smoothing. With SMC data and unmanned aerial vehicle (UAV) platform derived imaging hyperspectral imagery collected from the cropland in Fukang Oasis, Xinjiang Uyghur Autonomous Region, China. Then, the raw hyperspectral reflectance data were transformed into five preprocessing, i.e., SG, SG-FD, CR, Abs and Abs-FD. In addition, the relationships between SMC and pretreated difference index (DI), ratio index (RI), normalization index (NDI) and perpendicular vegetation index (PVI) were discussed. The correlation coefficients between each spectral index and SMC were also computed. Based on the optimal spectral index and pretreatment scheme, the hyperspectral quantitative estimating model was constructed for the dictation of SMC in oasis cropland in arid area. The result showed that the correlation between pretreated spectral index and SMC was improved to some extent, and the PVI (R644, R651) based on Abs preprocessing was the best with correlation coefficient of 0788. The cubic fitting function was optimal. On the basis of noise elimination, the multivariable SMC estimation model based on different preprocessing schemes could detect much finer spectral information from reflectance data, reduce the error caused by the single spectral index, and further improve the quantitative estimation effect of the model. The prediction accuracy of the Abs model was the most prominent, with R2c of 0.84， RMSE of 2.16%， R2p of 0.91 and RMSE of 1.71%. The effect of the SMC estimation model constructed was based on the preprocessing and noise elimination. The constructed SMC estimation model could reduce the error of independent single variable; and further resolve the problem of over fitting. The model could be used for hyperspectral mapping and performance estimating. The research result could provide a novel perspective and scheme for the remote sensed detection of soil water condition, especially in the arid and semiarid areas.

Abstract:The traditional tree species identification depends on timeconsuming and laborintensive efficiency of artificial field survey. In order to more effectively utilize the point cloud data identification tree of groundbased LiDAR, taking Beijing Forestry University as the research area, and FARO Photon 120 groundbased LiDAR was used to obtain point cloud data of a sample set of 92 trees, four tree species in the study area. According to the threedimensional coordinate values of point cloud, the six treemeasuring factors of breast diameter, height of branches, height of tree, height of crown, width of crown, and the longest direction of vertical trees in the study area were extracted, and the extracted treemeasuring factors were combined. The robust tree features six parameters, namely crown length tree height ratio, DBH height ratio, crown height tree height ratio, branch angle, crown length ratio, maximum crown width and vertical direction. For the ratio of crown width, the tree species were automatically identified by using the treemeasuring factor and the combined feature point parameters to support the tree sample by using the support vector machine, the classification regression decision tree and the random forest. The results showed that for the tree identification method using treemeasuring factor, the average accuracy of recognition was 0.765, and the average recall rate was 0.778. Among the three identification methods, the best effect was classification regression decision, followed by random forest, and finally support vector. Using the combined feature parameter tree identification method, the average accuracy of recognition was 0.891, and the average recall rate was 0.896. The best method was random forest and support vector machine, followed by classification regression decision. In general, the combined feature parameter method had higher accuracy and recall rate of single tree species or overall than those of the treemeasuring factor method, random forests were relatively the best for three different classification methods. The research result showed that the tree species identification classification combining the point cloud obtained by ground-based LiDAR and different machine learning classification methods could achieve satisfactory results and save a lot of time and manpower.

Abstract:A new method was proposed for early diagnosis of disease and pest level based on stem water content, which provided early warning for diseases and pests. Lagerstroemia indica seedlings with different health levels were monitored for acquiring stem water content. Then the features of stem water content were respectively extracted by two methods, including key parameter and principle component analysis. Ultimately, some supervised and unsupervised models were established for early diagnosis of disease and pest level on Lagerstroemia indica. Judging from variance analysis, the effects of health level on four key parameters (daily minimum, maximum, average and range of stem water contents) were all in very significant difference. Judging from principle component analysis, the cumulative contribution rate of the first four principal components of stem water content reached 99.7%. Among supervised models, BP model with input of PCA features performed the best and its average recognition reached 98%. Among unsupervised models, Kmeans model with input of PCA features performed the best and its average recognition rate reached 92%. Hence, stem water content can be chosen as a reliable index for early diagnosis of plant disease and pest level. The PCA features were superior to the key parameter features. The performance of supervised models was better than that of unsupervised models.

Abstract:The seed orchards design is the basic work for forest tree breeding. The goal of seed orchards design is to minimize the inbreeding between clones and guarantee the high genetic effects in seed orchards. The data source was genetic distance between the 1st, 1.5th and 2nd seed orchards of Pinussylvestris var. mongolica in Inner Mongolia Honghuaerji Sylvestris National Seed Areas by using SSR molecular marker technique. Considering the complex relationships between parents, the scheme of seed orchards was achieved by improved fruit fly optimization algorithm. The result was compared with other intelligent optimization algorithms and traditional algorithms, and it was showed that the speed and effectiveness of the improved fruit fly optimization were significantly better than those of other algorithms. After executing 200 times respectively, its maximum value was significantly lower than the minimum value of other algorithms. Finally, the improved fruit fly optimization design scheme was compared with the completely random design scheme and the genetic algorithm design scheme. Multiple same clones existed adjacent to each other in the completely random algorithm design, but the genetic algorithm and the improved fruit fly optimization design program did not appear as close neighbors of the same clonal ramets. However, the preferred mating of the improved fruit fly optimization design scheme was superior to the genetic algorithm design scheme. Based on the genetic distance to deal with the complex relationships of the parents, using the intelligent optimization algorithms to design seed orchard can provide reference for the design of highgeneration seed orchards.

Abstract:The object was to study the response of plant leaf traits and their related relationships to the thermal environment effect of urban underlying surface and its ecological tradeoff strategy. Results showed that specific leaf area, chlorophyll content, stomatal area, stomatal aperture and leaf nitrogenphosphorus ratio were all increased firstly and then decreased with the increase of environmental surface temperature, which was expressed as grassplanting bricks surface, grass surface, marble surface, cement surface, brick surface, asphalt surface from large to small. While the leaf dry matter content, leaf tissue density, stomatal density, leaf nitrogen content, leaf phosphorus content and leaf vein density showed opposite changes, which were expressed as asphalt surface, brick surface, cement surface, marble surface, grass surface and grassplanting brick surface from large to small. There was a certain correlation between plant leaf functional traits. Specific leaf area showed a significant negative correlation with leaf dry matter content, leaf tissue density and stomatal density (P<0.01), and a significant positive correlation with leaf nitrogen content and leaf phosphorus content (P<0.01). Leaf dry matter content showed a significant positive correlation with leaf tissue density, leaf vein density and leaf nitrogen content (P<0.01). Stomatal density was significantly and negatively correlated with stomatal aperture and stomatal area (P<0.05), and significantly and positively correlated with leaf vein density (P<0.05). Leaf vein density was significantly and positively correlated with leaf nitrogen content (P<0.05) and leaf tissue density (P<0.01). With the increase of surface temperature, the correlation between plant leaf traits was firstly increased and then decreased. The small temperature increase was generally beneficial to strengthen the correlation between leaf functional traits, which significantly reduced its correlation relationship when the temperature was too high. In urban ecosystems, plant leaves showed low specific leaf area, chlorophyll content, stomatal area, stomatal aperture and leaf nitrogenphosphorus ratio, and high leaf dry matter content, leaf tissue density, stomatal density, leaf nitrogen content and leaf phosphorus content. The research further verified the existence of the economics spectrum of the lower temperature of high temperature stress habitat on the underlying surface of the city, and it was a “quick investmentreturn” type in the global leaf economics spectrum, which provided an important theoretical basis for the selection and configuration of urban greening plants and urban planning. The study further validated the existence of economics spectrum in the urban system, which was a “quick investmentbenefit” type.

Abstract:In order to further elucidate the effects of different water and nitrogen regulation models on the accumulation of ammonium and nitrate in different soil layers and the effectiveness of soil nitrogen in the black soil region of cold area, based on field plot experiment and 15N tracing microzone test, the inorganic nitrogen and NH+415N and NO-315N accumulations of nitrogen in soil profiles under different water and nitrogen regulation models were studied, and the effect of different water and nitrogen regulation models on soil nitrogen availability was calculated according to the results of isotopic determination. The results showed that the accumulation of soil inorganic nitrogen and fertilizer nitrogen with inorganic nitrogen form residue in the soil profile was increased with the increase of nitrogen application and decreased with the increase of soil depth in two irrigation modes under controlled irrigation and conventional irrigation. The accumulation of inorganic nitrogen and nitrogen in the form of inorganic nitrogen in surface soil (0~20cm) of paddycontrolled irrigation mode under different nitrogen application rates was higher than that of conventional irrigation. The total amount of inorganic nitrogen and NO-315N in 20~40cm and 40~60cm soil layers was lower than that of conventional irrigation, and the accumulation of NH+415N in 40~60cm soil layer under low nitrogen fertilization between two irrigation modes was not significant (P>0.05). The NO-315N accumulation of 20~40cm soil layer in conventional irrigation mode at the same nitrogen application rate was 10~11 times than that of controlled irrigation mode. The NO-315N accumulation of 40~60cm soil layer was nearly three times higher than that of control irrigation mode. Totally 77.77%~84.51% of the accumulation of nitrogen under ricecontrolled irrigation mode at different nitrogen application rates was from soil nitrogen, which was 12.91%~23.12% higher than that under conventional irrigation, and the “A” value expressing soil nitrogen availability in ricecontrolled irrigation mode under the same nitrogen application was increased by 9.41%, 5.65% and 3.69%, respectively. Compared with conventional irrigation, the ricecontrolled irrigation mode can effectively improve the nitrogen efficiency of paddy soil, reduce the leaching loss of fertilizer nitrogen, and play an important role in saving water and reducing emissions, and the research results can provide a reference for the formulation of reasonable water and nitrogen control measures in the black soil area.

Abstract:It is of great significance for the sustainable development of agriculture in the arid and semiarid region to seek effective straw resources returned to the farmland. A twoyear field experiment was conducted to evaluate the effects of different pretreated straw returned to the farmland on the dynamics of several ecophysical characteristics of plant shoot height, leaf area index (LAI), aboveground biomass, canopy cover (CC), corn yield, soil water content, evapotranspiration and water use efficiency (WUE) so as to investigate the optimal scheme of the pretreated straw practices in 2014 and 2015. The experiments included two ammoniated straw levels (A0: no ammoniated straw; A1: ammoniated straw) and two straw length levels (L0: wheat straw was crushed into straw debris; L1: length of wheat straw was greater than 50mm). The results indicated that the average volumetric soil water contents of ammoniated short wheat straw (wheat straw was crushed into straw debris) plowed into the soil (A1L0) were significantly higher than those of long wheat straw (length of wheat straw was greater than 50mm) plowed into the soil (A0L1) by 10.7% in 2014 and 6.4% in 2015 during the summer maize growing season, respectively. Meanwhile, the treatment of ammoniated short wheat straw (wheat straw was crushed into straw debris) plowed into the soil (A1L0) could significantly increase average green canopy (CC) than other treatments by 3.7%~10.7% during the filling stage in two years, consecutively. Compared with other treatments, the treatment of A1L0 could significantly enhance average biomass, average corn yield and water use efficiency (WUE) by 2.1%~9.5%, 2.8%~9.1% and 1.7%~7.4% during the maturity stage in two years, respectively. The treatment of A1L0 could significantly increase the average corn yield and water use efficiency of summer maize. The average volumetric moisture content at 0~160 cm soil layers of ammoniated treatments were significantly higher than that of A0L0 and A0L1 treatments, and the ammoniated treatments (A1L0 and A1L1) significantly increased the crop water use efficiency in different growth periods. While the tendency between different treatments of water consumption was not significant, therefore, the treatment of ammoniated short wheat straw plowed into the soil (A1L0) can effectively promote the growth and yield of summer maize, which was a better measure for keeping soil water, promoting corn yields and enhancing water use efficiency (WUE).

Abstract:The Hetao Irrigation District in the Inner Mongolia is one of the most important bases for commodity grains in China. However, there was a substantial reduction in the total water quantity diverted from the Yellow River. In order to alleviate the crisis of water shortage and promote agricultural watersaving in the irrigation district, a twoyear field experiment was conducted, in which five different threshold values of soil matric potentials (SMP) were set to trigger the mulched drip irrigation for spring maize, i.e., -10kPa (S1), -20kPa (S2), -30kPa (S3), -40kPa (S4) and -50kPa (S5). The soil water distribution, crop growth, and water use efficiency (WUE) were studied for the different treatments. The results showed that soil water contents varied significantly at different SMP threshold values during the two growing seasons of spring maize. The weighted averages of volumetric water content in the 0~60cm soil profile were increased significantly with the increase of SMP (p<0.05). When under lower SMP threshold values, plant height and leaf area index (LAI) of maize were relatively lower during the growing season. And premature senility of maize was observed when under the SMP threshold value of -50kPa. Aboveground biomass, hundredgrain weight and number of grains per spike were increased with the increase of SMP threshold values. When under higher SMP threshold values, higher maize yields were obtained. The yields of treatments of S1, S2 and S3 were significantly higher than those of S4 and S5 (p<0.05), but there were no significant difference among S1, S2 and S3. With the decrease of SMP threshold value, WUE was increased first and then decreased. The highest WUE value was obtained when under the SMP threshold value of -30kPa. Therefore, both taking into account the yield and WUE, it was recommended that the SMP value of -30kPa can be the threshold value to trigger mulched drip irrigation for spring maize production in the Hetao Irrigation District.

Abstract:In order to reveal the residue of fertilizer nitrogen in paddy soil under the watersaving irrigation model in the low temperature black soil area of Songnen Plain, two irrigation modes were set up in the field experiment, which were controlled irrigation and conventional flooding, and three nitrogen levels (85kg/hm2, 110kg/hm2 and 135kg/hm2) and six treatments. At the same time, by using the method of 15N tracer in situ in the field plot, the basal, tillering and panicle nitrogen fertilizers were labeled and treated with a total of 18 parts. The residue of fertilizer nitrogen in paddy soil after rice harvest was studied, and the distribution of fertilizer nitrogen in 0~60cm soil in paddy field was investigated. The results showed that the residual rate of basal nitrogen in paddy soil was 29.7%~32.7% under different nitrogen levels, and the residue rate of tillering fertilizer was 54.9%~57.3%, and the residue rate of panicle was 29.4%~35.4%; the total residue rate of fertilizer nitrogen in soil was 36.4%~37.1%, the residual rate of the fertilizer nitrogen in the soil was higher than that of the conventional flooding irrigation under the same nitrogen application. There were significant differences in the residues of fertilizer nitrogen in the same depth soil under different irrigation modes. Under different nitrogen application conditions, the residue in rice paddy soil (0~20cm) was higher than that in the normal flooded irrigation mode during the growth period of paddyfield. The residual amount of 20~40cm and 40~60cm soil was lower than that of conventional flooded irrigation. Compared with the conventional flooding irrigation, the riceirrigated model can improve the residue of fertilizer nitrogen in root soil (0~20cm), and reduce the loss of fertilizer nitrogen, and the residual fertilizer nitrogen can supplement the soil nitrogen reservoir in the black soil area to some extent. It was beneficial to soil protection and fertility improvement of paddy field in black soil area. The correlation analysis showed that the total residue of fertilizer nitrogen in soil was positively correlated with the residue of fertilizer nitrogen in soil, and the residue of basal and spike fertilizer was significantly positive. The research results provided a reference for the formulation of suitable water and nitrogen regulation model in the black soil region, effectively managed and made full use of residual nitrogen fertilizer, and improved the paddy field ecological environment in black soil area.

Abstract:In order to study the mode of application of biochar in the black soil area, a field runoff plot of 3° slope cultivated land in Northeast China was studied for a period of three years. In 2015, according to the amount of biochar applied, five treatments of C0 (0t/hm2), C25 (25t/hm2), C50 (50t/hm2), C75 (75t/hm2) and C100 (100t/hm2) were set up. The treatments were applied with the same amount of biochar in 2016 and 2017, respectively. The changes of soil physical and chemical properties, the effects of soil and water conservation and the effects of watersaving and yieldincreasing were studied after applying biochar for three consecutive years in black soil area. And a model was established based on an improved TOPSIS to comprehensively evaluate the application mode of biochar. The results showed that the soil organic carbon density, pH value and the applied amount of biochar presented a linear increasing trend, the soil bulk density and the applied amount of biochar showed a linear decreasing trend, and the longer the service life was, the more obvious the effect was. The field water holding capacity and the applied amount of biochar were increased linearly in the first year. The C100 treatment had the largest amount of water in the field, which was 3548%. And the field water capacity and applied amount of biochar during the twoyear and threeyear continuous applications showed a quadratic parabola changes. The parabola changes reached the maximum at C50 treatment, which were 36.20% and 36.24%. The threeyear annual runoff, annual soil erosion and applied amount of biochar were firstly reduced and then increased by the quadratic parabola. Continuous application of two years of 50t/hm2 biochar had the best reduction effect and antierosion effect. The application of biochar for three consecutive years increased soybean yield and water use efficiency, The highest increase in yield and water use efficiency in each year were C75 (21.8%, 25.3%), C50 (33.3%, 27.6%) and C50 (24.1%, 19.8%), respectively. Under the conditions of different biochar application rates and application years, the improved TOPSIS model can objectively and clearly describe the process of soil productivity changes, and summarize the proposed biochar application mode. That was, continuous application of 50t/hm2 biochar for two years gave the best improvement in soil productivity, which followed by 75t/hm2 for a year. The results of this research can provide a theoretical basis for practical production.

Abstract:The leaching loss of soil nutrients along with water is serious in the process of agricultural planting, it not only wastes fertilizer resources, but also causes eutrophication of surface water and further threatens groundwater quality, and the phenomenon is more serious during the application of liquid bioorganic fertilizer biogas slurry. Biochar has strong adsorption due to its special physical and chemical properties, adding biochar to soil to reduce the loss of nutrient has become a research focus. However, its leaching process and law still need to be further studied. To investigate the effects of soil nutrient leaching after biogas slurry was applied under different conditions, the orthogonal design of threefactor and threelevel L9 (33) was adopted through indoor soil column simulation test. The effects of biochar addition amount（2%, 5% and 10%）, leaching intensity（46mL, 137mL and 250mL） and biogas slurry addition amount（100mL, 200mL and 300mL）on soil nutrient leaching and vertical distribution of soil nutrients after leaching were systematically studied. The results showed that soil nutrient leaching was mainly concentrated in the early stage of leaching (leaching was mainly concentrated in the first five times of leaching), the leaching loss amount remained at a low level and gradually became stable at later stage. The effects of various factors on the leaching loss of ammonia nitrogen, rapidly available phosphorus and rapidly available potassium were successively the leaching strength, amount of biochar added and amount of biogas slurry applied, however, the effects on the loss amount of nitrate nitrogen leaching were successively the amount of biochar, amount of biogas slurry and leaching intensity. Compared with the control group, the nutrient leaching loss of biochar treatment was significantly reduced. The content of various nutrients of the soil with depth of 0~20cm added with biochar was significantly higher than that of the soil with depth of 20~40cm without biochar. The effects of various factors on the content of ammonia nitrogen, nitrate nitrogen and rapidly available potassium in soil were significantly different in longitudinal depth, but there was no significant difference on the content of rapidly available phosphorus. The experiment laid a theoretical foundation for the research on leaching effect of biochar addition and biogas slurry application on soil nutrients, the research and application of biochar as a soil improvement additive as well as the scientific and reasonable application of biogas slurry in the field production can be accelerated.

Abstract:In order to evaluate the reliability of dual crop coefficient approach on calculating evapotranspiration of summer maize with mulched drip irrigation in arid region, the evapotranspiration of maize was measured by stable carbon isotope technique and water balance methods in measurement pits in 2016 and 2017. Five treatments were set up according to fixed irrigation cycle (W1, W2 and W3) and variable irrigation cycle (W4, W5) and the corresponding values were also calculated by dual crop coefficient approach. Experimental results showed that evapotranspiration calculated by dual crop coefficient approach had positive correlation with those values obtained by water balance methods, and the root mean square error was about 10mm. The crop transpiration calculated by dual crop coefficient approach also had positive correlation with those values obtained by stable carbon isotope technique, and the root mean square error was about 20mm. By calculation and analysis on the root mean square error, regression coefficient and consistency index, it can be concluded that dual crop coefficient approach was an effective method to calculate and distinguish evapotranspiration of summer maize with partial mulched drip irrigation in arid region. In whole growing season of summer maize, the simulated soil evaporation accounted for 21.33% and 23.97% of evapotranspiration and plant transpiration accounted for 78.67% and 76.03% of evapotranspiration in 2016 and 2017, respectively.

Abstract:Effects of tillage on soil carbon and nitrogen retention and stratification in ricewheat system were studied to provide a theoretical basis for exploring tillage methods which could be beneficial to the construction of soil organic carbon (SOC) and total nitrogen (TN) pools and the improvement of soil fertility in farmland. A fouryear field experiment was conducted based on Heheng demonstration park of ecoagricultural science and technology, including four treatments of minimum tillage with straw retention (MT), rotary tillage with straw retention (RT), conventional tillage with straw retention (CT) and conventional tillage without straw retention (CT0). Soil at 0~20cm depth was collected to determine soil bulk density, content of SOC and TN. Then the ratio of C to N, the stratification ratio and the SOC and TN storage (using the equivalent soil mass approach) were calculated. Results showed that the contents of SOC and TN in 0~5cm, 5~10 and 10~20cm depths were increased by MT, RT and CT, respectively. Soil C∶N ratio at 10~20cm depth was decreased with the increase of tillage intensity. MT significantly increased the stratification ratio of SOC and TN, while the stratification ratio of C∶N ratio at 0~5cm and 10~20cm depths was increased with the increase of tillage intensity. MT increased the SOC stocks at 0~20cm depth and the TN stocks at 0~10cm depth, but the TN stocks at 0~20cm depth were lower than those of RT and CT. Straw retention significantly increased SOC and TN contents and C∶N ratio, which were beneficial to SOC and TN sequestration, but it had no significant effect on stratification ratio of SOC and TN contents at 0~20cm depth.

Abstract:To explore the effects of biochar and fertilizer interaction on tomato soil moisture content and yield, five biochar levels were set at 0t/hm2 (B1), 10t/hm2 (B2), 20t/hm2(B3), 40t/hm2 (B4) and 60t/hm2 (B5); two fertilization levels were set at midfertilizer (F1) and lowfertilizer (F2). The results showed that with the increase of biochar application, the soil water content of the highbiochars were increased. Among them, B4F1 was the most significant and was increased by 40%. However, the soil water content in 20~40cm was opposite to that of 0~20cm. Compared with the control, it showed a downward trend. Among them, B4F1 and B4F2 had the smallest soil water content, which was only 70% of the control. The overall changing trend of soil water content in 40~80cm was consistent with that in 20~40cm. After the application of biochar, the changing range (Ka) and variation degree (Cv) of soil water content were decreased. For the same depth of soil, with the increase of application rate, the biochar Ka and Cv appeared decreasing trend. Compared with the control, the Cv under high application of charcoal (B4F1, B4F2, B5F1 and B5F2) was relatively small. With the growth of tomatoes, the effect of soil water content on the vertical profile showed that compared with the control the higher application of biochar (B4F1, B4F2, B5F1 and B5F2) effectively maintained the effective water. With the increase of biochar application, the increase in tomato yields was firstly increased and then decreased, and both were higher than that of control. The yield of B4F1, B4F2, B5F1 and B5F2 were increased by 46.34%, 58.61%, 49.63% and 39.18%, respectively. Among them, the yield of B4F2 treatment was the highest. There was no significant difference in different fertilization treatments. The research results can provide a basis for agricultural production in semiarid regions of Inner Mongolia.

Abstract:Acidic ionic liquids (ILs) are used as promising and environmentallyfriendly catalysts for levulinates synthesis, which can replace the sulfuric acid owing to their beneficial characteristics such as high catalytic activity, high selectivity, low corrosion of equipment and ease of recycling. Eight different acidic ILs were examined as catalysts in the synthesis of ethyl levulinate (EL) from carbohydrates with ethanol. Among them, the cations of ILs were imidazole, pyridine and triethylamine salts, and the anion ions were inorganic acids and organic acids. The structures of ILs were confirmed by 1H NMR and13C NMR. All of the ILs exhibited excellent thermal stability over 200℃ through the TG-DTG. The acidity of the ILs was investigated by determining the Hammett acidity functions under UVvisible spectroscopy by using 4nitroaniline as indicator. The introduction of a SO3H group into the IL greatly increased its Brnsted acidity. Anions of ILs had a great influence on the acidity of ionic liquids, and cations with imidazoles were more acidic than pyridine and triethylamine salts. It was found that the \[BmimSO3H\]HSO4 showed the best catalytic activity among all the ILs. The activity of catalytic synthesis of EL was closely related to the Brnsted acid. The highest EL yield of 5679% was obtained for the reaction carried out at 170℃ for 60min with 2mmol \[BmimSO3H\]HSO4 as catalyst and using glucose as the substrate. Furthermore, the ILs remained high activity and stability after reused for 5 times. On the whole, \[BmimSO3H\]HSO4 had stable structural properties in the process of catalytic alcoholysis of carbohydrates into EL, showing a better catalytic conversion efficiency.

Abstract:The high water content is one of factors limiting cow manure treatment approach. The hydrothermal carbonization (HTC), which can convert cow manure with high water content into hydrochar, is considered as a potential approach for safe disposal and resource utilization of cow manure. Fresh cow manure was hydrothermally treated at 190℃ and 260℃ for 1h, 6h and 12h, respectively. And then the collected solid products were determined for the physicochemical properties. Based on entropyweight TOPSIS model, the agricultural value was evaluated. The aim was to investigate the effect of temperature and time on hydrochar nature, and then provide a theoretical reference for its agricultural application. The results showed that physicochemical properties of hydrochar was changed with carbonization temperature and duration. Compared with the hydrochar produced at 190℃ for 1h, carbon, total phosphorus and potassium concentrations of hydrochar produced at 260℃ for 12h were increased by 17.88%, 39.06% and 85.19%, but yield, H/C atomic ratio, O/C atomic ratio, (O+N)/C atomic ratio, ammonium nitrogen, exchangeable P and K contents were reduced by 26.65%, 24.00%, 68.42%, 64.29%, 98.91%, 89.26% and 42.30%, respectively. Meanwhile, carbonization degree was increased significantly. With high temperature and long duration, position of functional group absorption peak was varied less, intensity of oxygen functional groups absorption peak was reduced, but intensity of metalhalogen chemical compound performed an opposite trend. The higher reaction temperature and longer residence time caused less surface charges, lower pH value dependence, smaller specific pore volume and specific surface area. Overall, temperature had a large impact on hydrochar nature compared with reaction duration. Cow manure hydrochar produced at low temperature for short time was more suitable as a soil conditioner due to its higher agricultural value.

Abstract:Taking rape straw and anthracite and bituminous coal as the research object, based on the simultaneous thermogravimetric technology, the dynamic characteristics of cocombustion were studied systematically with different mass fractions of wheat straw (100%, 60%, 40%, 20%, 10% and 0) and the ratio was optimized. The results showed that WS was rich in volatile matter with a content of 75.69%, while bituminous coal had the highest fixed carbon content (54.77%). Therefore, the fuel ratio (fixed carbon/volatile) of BTC (167) was much larger than that of WS (014), indicating that bituminous coal was more conducive to combustion. There was significant difference on cocombustion characteristics under different mass fractions from TG and DTG curves. From DTG curves of cocombustion, it can be seen that as the proportion of wheat straw was decreased, the volatile combustion peak was gradually decreased from 2079%/min to 208%/min (WS10%). The maximum rate of fixed carbon combustion of wheat straw (4033%/min) appeared at 419℃. The ignition temperature was not significantly improved when the ratio of straw was declined to 10%, which was within 260~268℃, indicating a desirable performance of ignition. While the burn out temperature was significantly improved along with the decrease of straw from 520℃ (WS) to 596℃ (BTC). The comprehensive index (SN) value was decreased from 8.78×10-7%2/(K3·min2) to 1.17×10-7%2/(K3·min2) as the straw ratio was decreased, indicating that the combustion performance was gradually weakened. However, the group WS40% with a SN value of 3.60×10-7%2/(K3·min2) can ensure better combustion behavior. From DSC analysis, mixture with 40% propotion of WS can release heat up to 84.14% of BTC’s.In summary, based on the evaluation of combustion performance and improving heating value of mixture, the mass fraction of 40% was recommended for wheat straw when blended with bituminous coal for cocombustion.

Abstract:In order to guide the intensive aquaculture effectively and improve the accuracy and stability of water temperature prediction, based on the analysis of water temperature factors, a prediction model (EMD-IGA-SELM) was proposed with the combination of empirical mode decomposition (EMD), improved genetic algorithm (IGA) and improved extreme learning machine (SELM). Firstly, the outlier and missing data were corrected with the calculation of composite meteorological index. Secondly, the Pearson correlation was utilized to explore the relationships between affecting factors and water temperature, and construct the input and output of prediction model. Then, Softplus function was used as activation function of SELM to replace Sigmoid. The best weight and threshold of SELM were obtained from the IGA, which introduced the chaotic sequence to traditional GA. Finally, EMD algorithm was applied to decompose the original water temperature time series into a series of intrinsic mode function (IMF). IGA-SELM prediction models were trained in each IMF sequence, and the predicted values were calculated by the sum of predicted value in each IMF sequence. The experimental results showed that EMD-IGA-SELM had better prediction accuracy, and the mean absolute error (MAE), mean absolute percentage error (MAPE) and root mean square error (RMSE) of GA-SELM were 0.1233℃, 0.0043 and 0.1478℃, respectively. Research results met the practical needs of the aquaculture and provided decision support for water quality management and control.

Abstract:In order to explore a kind of ventilation method with heat preservation, high efficiency and low operating cost about the chicken house, according to the principle of thermal balance, the fresh air ventilation system was adopted for the ventilation of chicken house, which used a high efficiency gasair plate heat exchanger. It was different from the traditional platefin sandwich type heat exchange core body, but the special design at the inlet and outlet increased the length of countercurrent portion and reduced the length of crossflow portion. The fresh air passage and exhaust passage were arranged at intervals in honeycomb body. It was a heat recovery ventilation system with low production cost, simple manufacturing process and high heat exchange efficiency. The temperature, relative humidity, sensible heat exchange efficiency, and growth performance of the chicken house were monitored with a fresh air ventilation system installed, and the cost of regenerative fresh air ventilator was analyzed. The test results showed that the temperature and relative humidity of test group and control group can meet the requirements of each week. And at the fourth week, the air temperature and relative humidity in the test group were 24.91℃ and 48.96%, respectively, which were significantly lower than those in the control group （P<0.01). At the fourth week, the carbon dioxide mass concentration, ammonia mass concentration, PM25 concentration and PM10 concentration in the test group were 2.36116mg/m3, 7.28mg/m3, 12.54mg/m3 and 107.58mg/m3, respectively, which were significantly lower than those in the control group （P<0.01). The air quality and ventilation effects of the test group were better than those in the control group. The average sensible heat exchange efficiency of the fresh air ventilation system can reach 80% during 19:00—07:00. The fresh air ventilation system can greatly recover the heat from the exhaust gas; there was no significant difference in length and body weight between the test group and the control group （P>0.05), which indicated that the heat recovery and fresh air ventilator can meet the growth needs of the chickens; from the heat recovery effect point of view, when the outdoor temperature during the test was -8~8℃, the recovery cost days was about 80d. When the outdoor temperature was lower than 19℃, the fresh air ventilation system can balance the heat recovery efficiency and ventilation requirements and meet the ventilation and energy saving needs of livestock houses. It was concluded that it had a good ventilation effect when the fresh air ventilation system was used in a chicken house. It was an effective way to solve the contradiction between heat insulation and ventilation of a chicken house.

Abstract:In order to solve problems relating to online recognition of stems/calyxes and bruise of apples, a selfdesigned machine vision inspection system was applied to online image acquisition of apples, images of three different motion states were synthesized by the automatic segmentation synthesis algorithm, and stems/calyxes and bruise in images of apples were extracted by the areaofinterest extraction algorithm. To study applicability of different characteristics of images, early bruise midterm bruise and later bruise were identified through variables of textural features and edge gradient features respectively. As textures of stems and calyxes were more complex than those of early and middle bruise, the support vector machine model based on two variables of textural features, namely entropy and energy/angular second moment, was used and showed a good effect with an overall accuracy of 97%. Due to brown stain and depression of the most later bruises, its textural characteristics were similar to those of stems and calyxes. Hence, later bruise can not be distinguished from stems and calyxes with parameters of textural characteristics. As a result, an edge gradient features extraction algorithm was designed to extract peak intensity and peak positions of later bruises, stems and calyxes and a support vector machine model was created with an overall accuracy of 96%. On this basis, a comprehensive inspection algorithm about stems/calyxes and bruise of apples was designed. Totally 80 different types of bruiserelated algorithms were purchased to verify this algorithm and its accuracy reached 95%. Testing results showed that online recognition of stems/calyxes and bruise of apples could be realized through this algorithm.

Abstract:The matching method for time temperature indicator (TTI) is the critical factor affecting the application of intelligent indicator. Most current methods depend mainly on the corresponding parameters coupling, correlation analysis and practice logistics verifying without concerning about the reaction extent in matching mechanisms between TTI and agriproduce which needs to be monitored. The relationship between remain shelf life and reaction extent was established and a new matching method between TTI and agriproduce was constructed through keeping the consistency of their reaction extents based on the norder kinetic models. After a series of analysis and formula, the condition for matching between them was the valid reaction time or remain shelf life of them under any reasonable isothermal process were equal, or the contour lines of them were coincident, no matter whether the orders of their kinetic models were equal or not. In this case, there was a proportional relationship between the reaction speeds of them which was a key character under matching condition. By using the result above, three kinetic models with different orders were constructed, and the matching method was verified based on the consistency of their reaction extents, the appreciate kinetic functions of TTIs for indicating the firmness quality of Crimson seedless grape precisely under alternative and constant temperature logistic was deduced in different order kinetic models. The conclusions validated the feasibility and effectiveness of the proposed method, which could promote the application of TTIs.

Abstract:In order to explore the mechanical properties of barley grain in the operation process of harvesting, threshing, storage, transportation and so on, the compression experiment and finite element simulation method (FEM) of barley grain were carried out. At present, the conventional modeling method of irregular shape agricultural material was simplified into regular body to deal with. Because of the difference between barley grain and simulation model in size and surface shape, the actual physical parameters of barley grain were not suitable for the finite element model which was approximately treated, thus existing a few problems, such as more sample consumption and cumbersome measurement. Five wet basis moisture content (7.94%, 11.02%, 14.29%, 16.85% and 20.37%) and three kinds of loading directions (horizontal, width and vertical directions) of barley grain were selected as test materials. Mechanical parameters like and different forms of damage, rupture strength, elastic modulus and compression work of barley grain were measured by universal materials tester. The compression tests results showed that under these conditions the elastic modulus of barley grain was 87.39～167.84MPa, the rupture strength of barley grain was 70.40～157.32N, the yield strength of barley grain was 0.85～2.12MPa, and the maximum strain of barley grain was 0.26%～1.15%. The results showed that the elastic modulus, rupture strength and yield strength of barley grain were descended obviously with the increase of moisture content. The rupture strength in width direction was the maximum and in vertical direction was the minimum under the condition of the same moisture content. The elastic modulus in horizontal direction was bigger than that in vertical direction. Then the threedimensional finite element model of barley grain was built based on 3D laser scanning technology, point clouds of barley grain were acquired by the software Geomagic Studio which were processed by cloud processing and reverse modeling techniques to get high quality point clouds, thus a geometric model highly similar to the real barley grain was obtained. And mechanical analogue simulation was performed based on the geometric model. The compression test results and finite element solutions were compared, and the maximal difference was 7.2%, which showed that the modeling method of barley grain based on 3D laser scanning technology was effective and accurate. The modeling method of barley grain provided a new technology to improve the accuracy of the irregular agricultural material model and reduce the simulation error. Meanwhile, the mechanics parameters and the rules of barley grain could provide reference for its utilization and optimization of related processing machinery.

Abstract:In order to optimize matching of the tractor powertrain and improve the power and fuel economy of the tractor, a new matching optimization method for tractor powertrain was put forward based on the improved nondominated sorting genetic algorithmⅡ. The normal distribution crossover operator (NDX) was introduced to expand the spatial search range on the premise of ensuring the quality of the nondominated solution set. And meanwhile, the differential evolution mutation operator based differential evolutionary algorithm was used as directional guiding ideology to avoid falling into the local optimum and improve the uniformity of population distribution. Subsequently, by analyzing the design requirements and powershift transmissions produced by New Holland, Case IH and John Deere, the optimization model of transmission ratios was established with constraints such as vehicle speed, ratio of gear ratios, driving adhesion restriction, and so on. In this model, gear ratios were taken as input variables, and the optimization objective was to get the lowest drive power loss rate and the lowest specific fuel consumption loss rate. The proposed algorithm was used to optimize the tractor powertrain and compared with the original NSGA-Ⅱ and the weighted genetic algorithm. The experimental results showed that the distributed index SP of the proposed algorithm was smaller than that of the original NSGA-Ⅱ, which meant that the improved NSGA-Ⅱ could obtain a more uniformly distributed and precise optimal solutions. And after optimization of the improved NSGA-Ⅱ, the drive power loss rate and the specific fuel consumption loss rate of the tractor could be theoretically reduced by 41.62% and 62.8%, respectively, and the climbing angle of the first transport gear could be increased by 2.35% than before, which was better than NSGA-Ⅱ and the weighted genetic algorithm. The overall performance of the tractor was improved obviously which verified the effectiveness of the improved NSGA-Ⅱ algorithm. To sum up, this method could provide a certain reference for the design and optimization of the tractor transmission.

Abstract:Conventional agricultural chassis was difficult to adapt to the slope which put a severe test during the operation. Taking the auto leveling system as the research content, a twodegree of freedom platform and its selfcontrol system was developed. The mechanicalelectricalhydraulic multiphysics simulation model was established based on SimMechanics and SimHdraulics, which helped to analyze spatial kinematics through SimMechanics while hydraulic system simulation through SimHdraulics. Due to dualacting asymmetric hydraulic cylinders, a dualchannel PID control strategy was used to control following response, displacement error, velocity respectively and dualaxis inclination. The hydraulic cylinder with push and return movements could be regarded as different hydraulic cylinders with different piston areas. The characteristic of dualchannel PID control meant when errors were adjusted with different PID parameter values. The simulation results showed that the maximum following error was 1.90mm and the response time was 0.228s under dualchannel PID control. The equilibrium time in the limit state was 2.98s. Compared with singlechannel PID control, the maximum control error was reduced by 49.3%, and the response speed was increased by 45.8%. Tests under eight different gradients were performed. These results showed that the response time of the auto leveling system was 0.328s. With the increase of gradient, the maximum error of the test platform leveling was 1.14°, and the maximum root mean square error was 0.299°. The auto leveling system had a fast response, small following error, good followability and high control accuracy under the dualchannel PID control and it can meet the requirements of ring slope operation.

Abstract:With the dramatically growing use of agricultural highpower tractors, comfort of cab is an important problem in China. Because of the indirect impact with low comfort of cab, the productivity is restricted. Health of tractor drivers was also undermined by low comfort of the cab. 〖JP3〗Highpower tractors play an important role in tilling machine. The PM concentration in ambient air is very high (512mg/m3). 〖JP〗Foreign mainstream tractor comfortable cabs are enclosure cabs to protect PM into cabs. In the field research, enclosure cab can protest PM10 and PM25 very well except tilling work. The PM10 and PM25 concentration cannot reach the human healthy standard when tractor is tilling. The foreign research of PM cleaning system in tractor cab is at an initial stage and the research in Chins is empty. So, the PM research is meaningful. The concentration of PM10 and PM25 simulation was done based on collection data in other researches. Firstly, the concentration variety model and cleaning model were deduced according to the mass conservation theory. Then, the simulation was done under different cleaning methods (return, supply and freestanding filter) and cleaning efficiency (50%, 75% and 90%) by IAQx11-PM. The results showed that the relative cleaning efficiency of return and supply were 92.78% and 96.13%, respectively. These two methods could reach the international human healthy standard. The PM10 and PM25 concentrations in supply method could be lower than 800μg/m3. Although the relative cleaning efficiency of freestanding filter was between 48% and 66%, the international human healthy standard still could not be reached. The curve of PM10 and PM25 concentrations showed that supply method was the fastest to get stable statues (1h). Finally, the human inhalation exposure was calculated. It was indicated that HVAC design method should be used in comfort cab. This method could save the volume of air conditioner volume and control the temperature and PM concentration.

Abstract:In kinematic calibration of a serial manipulator, to avoid the complex process and determine the relation between measurement coordinates and robot base coordinates when using pose error, a distanceerror model was proposed, which placed its base on the geometric property of joint screw and error compensation scheme of adjoint transform. Comparing with other distanceerror models such as DH model and MDH model, the proposed model can guarantee the geometric constraints on the joint screw to be naturally satisfied. Furthermore, the physical meanings of the kinematic parameters involved in this model were explicit. As a result, it was relatively easy to evaluate the influence of each kinematic parameter on the distance errors. To enhance the robustness of the model, the kinematic parameters redundancy was studied by investigating the null space of the Jacobian matrix. It was found that the number of independent parameters was determined by the measurement method used to measure the distance errors. Specifically, let r be the number of revolute joints, then, the maximum number of the calibrated parameters was 4r-2, and the number became 2r and 3r-1 when measuring the errors by rotating the corresponding joint and taking the initial configuration as the reference, respectively. In order to verify the effectiveness of the proposed model and the correctness of the redundancy analysis, calibration experiments were performed on KUKA youBot with five degrees of freedom. It was found that the result about calibrated parameters obtained from the theoretic analysis was the same as that of experiment. Meanwhile, the mean distance error was decreased by 116 times after calibration than before calibration. Therefore, the kinematic accuracy of the robot can be greatly improved by the proposed distanceerror model.

Abstract:With the development of space technology, the highprecision instruments carried by spacecraft have higher requirements on the vibration environment. Active control of spacecraft microvibration was studied and analyzed. Firstly, according to the different vibration isolation requirements, the openloop transfer function of disturbance displacement transmission and disturbance force transmission of singleaxis vibration isolator and the closedloop transfer function based on force feedback were established respectively. Then, the disturbance displacement suppression was taken as an example to theoretically derive. The active vibration isolation effect based on force feedback PI control and linear active disturbance rejection control was analyzed, and the influence of Butterworth filter on active vibration isolation system was discussed. Finally, a singleaxis active vibration isolation experimental platform was built to verify the correctness of the theoretical derivation results. Linear active disturbance rejection control can achieve better vibration isolation effect in the full frequency range of 20~500Hz. The attenuation rate of microvibration can reach 10dB in the low frequency band and 20dB in the resonant frequency and high frequency.

Abstract:As an endeffector in the micromanipulation system, the compliant microgripper is of great importance in micro manipulations. A pseudorigidbody model of a novel compliant microgripper was established, and the kinematic equations were formulated based on developing and analyzing the pseudorigidbody model by using the principle of virtual work. The relationship between input and output displacements as well as the relationship between input force and output displacement were then derived. The analytical model was verified via 3D simulations by using ANSYS software. The simulation results were compared with the theoretical results and the error was less than 28% within the required range. Finally, the compliant microgripper was fabricated and the micromanipulation system was established. Then displacement experimental tests were conducted by using the fabricated microgripper. Experimental data was compared with both analytical and simulation results to further validate the accuracy of the analytical model. It was proved that the new microgripper displacement can get 8965μm with 1V voltage applied. And the error between the analytical results and experimental data was not more than 32% in useable range. The displacement characteristics were got by the pseudorigidbody model and verified by the simulation results and the experiments data. The microgripper can manipulate suitable subjects with size within 500μm to 679μm from the analysis results.

Abstract:Stiffness is one of the most important performance factors that should be considered for parallel mechanism. A semianalytical approach for the stiffness analysis of a 3-R[TXX-]RS parallel mechanism was presented with consideration of gravity. The force analysis was carried out by taking both gravity of all moving components and the externally applied wrench imposed upon the platform into account. The deflection analysis that considered the distributed gravity of all limbs and joint/link compliances was investigated. On the basis of the formulation of component stiffness matrices in the joint space, the stiffness model of the parallel mechanism was achieved. Based on a numerical example, the stiffness distributions and deflection distributions induced by gravity throughout the entire task workspace were evaluated, and the contributions of the component stiffness to the global stiffness and the contributions of the components gravity to platform deflection were investigated. Meanwhile, the effectiveness of the proposed modeling approach was verified by the FEA software at a typical configuration. Numerical example showed that in order to make the parallel mechanism with lightweight yet rigid design, the rigidities of different components, as well as the actuated and constraint rigidities of each component should be matched each other. For the considered 3-R[TXX-]RS parallel mechanism, the rigidity of the spherical joint should be improved while the rigidity of the revolute joint should be reduced, the actuated rigidity of the limb should be enhanced while the constraint rigidities of that should be reduced.

Abstract:Dynamic analysis of complex and fine structure often involves external load with different time scales. Meanwhile, a local refined mesh is needed at the analysis zone. The classical explicit-implicit mixed method was used to deal with such problems with the interpolation process of boundary data which was likely to cause computational instability. At the same time, a single time step would cause waste of computing resources. An improved explicit-implicit mixed asynchronous time step computing method was proposed with multiple boundary mesh. Node segmentation was used to divide the finite element model into explicit and implicit partitions. A compatible format predictive correction Newmark integration scheme was adopted in different partitions. A larger time step was used for implicit partition and a smaller time step for explicit region. The prediction waveform for explicit partition can be transmitted completely in the boundary mesh without truncation. Sparse storage row compression CRS format was used in the implicit partition and node data can be obtained by sparse direct solver. The node acceleration data for explicit and implicit partition were solved sequentially and efficiently. Numerical examples showed that the accuracy of the proposed method was higher than that of the traditional explicitimplicit mixed method and the computation time for dynamics analysis was further reduced.

Abstract:The process of two translation and two rotation (2T2R) parallel mechanism (PM) type synthesis was systematically discussed according to the method of topological structural synthesis of parallel mechanism based on position ad orientation characteristic (POC) equations. The structure synthesis of complex branches, the method of judging geometric assembly condition of parallel mechanism and the judgment of drive unit of the parallel mechanism were all illustrated with examples. The type synthesis of hybrid single open chain (HSOC) branch chains was the foundation of the type synthesis of parallel mechanism, five new HSOC branches were proposed based on the complex branch synthesis method by the idea of equivalent substitution of topology structure. Totally 15 kinds of 2T2R parallel mechanisms were synthesized and classified according to branch structure and number of moving platform. Totally 10 kinds of them were new structures. Furthermore, the topological characteristics of them were analyzed, including the Assure kinematic chain (AKC), number of independent displacement equations for parallel mechanisms, degree of coupling, type of degree of freedom (DOF) and motion decoupling. In addition, according to the characteristics of topological structure, the 2T2R mechanism was classified and analyzed. These structures were simple and easy to be assembled and manufactured. All these new structures had practical value.

Abstract:In traditional pressure control loops, the power elements use a conventional singleacting pump. When the circuit uses only one pump to provide pressure, the pressure control loop cannot meet the system’s need for multiple flows. The new multipump and multispeed motors were based on the double stator theory and a new type of hydraulic components was developed, which can achieve a pump (motor) multioutput. When the conventional singleacting pump and singleacting motor were used in the conventional hydraulic circuit, the hydraulic circuit at this time was a new type of hydraulic circuit. Due to the special nature of the components, the system can meet the needs of multiple outputs and multiple powers. Since the new hydraulic circuit reduced a lot of control elements, the new hydraulic circuit can save a lot of energy when implementing the same functions as the traditional hydraulic circuit. The experimental results of the new multipump and multispeed motor pressure control circuit showed that with the increase of the system pressure, the measured flow of the double stator pump was decreased; the volumetric efficiency of the double stator pump was decreased with the increase of pressure difference, the mechanical efficiency and total efficiency were increased with it. Although the error was caused by some uncontrollable factors, it verified the feasibility of the circuit and the rationality of hydraulic components. The experimental results laid the foundation for the innovation and development of multipumps (motors) for other hydraulic circuits.