Abstract:Real time efficiency is one of the bottleneck problems in the field of image processing, especially in the natural scene of the agricultural robot vision system. Nowadays superpixel segmentation algorithm was proposed as the high robustness to deal with the random uncertainty in natural scene. Simple linear iterative clustering(SLIC) has drawn much attention due to its outstanding performance in terms of accuracy， speed, antishadow and antihighlight. In this paper, by applying the Cauchy-Schwarz inequality, we derived a condition to leave unnecessary operations from the cluster inspection procedure. In the proposed algorithm, we reduced the redundant computation by using a robust inequality condition based on weighted L2 norm of pixel and cluster center representation. Then we put up with an advanced algorithm: FSLIC algorithm. We built a database with 2000 apple images in almost all natural conditions. Several kinds of extreme situations were chosen: high intensity of illumination light condition, low intensity of illumination backlight condition, uneven illumination of cloudy condition, adjacency and severe adhesion condition. The error rate curves of the insufficient segmentation, the hit rate curves of the boundary and execution time were analyzed with the 500 apple images; the GCE, FNR and FPR were detected with the 30 images in extreme condition. In the experimental results, it was confirmed that the GCE in Graphbased and FSLIC algorithm was reduced by 13% than BP algorithm, WT algorithm and SVM algorithm, the GCE in FSLIC algorithm was reduced by 19% than the traditional algrithms. The hit rate of the boundary in FSLIC algorithm was increased by 21.7% and the speed was 1.83 times than Graphbased algorithm.

Abstract:In order to solve the problems of low accuracy of cucumber leaf disease image segmentation in complex background, a new segmentation algorithm of cucumber leaf disease image based on saliency detection (SCLDSD) was proposed. The proposed algorithm mainly consists of two parts: saliency detection in cucumber disease image which is used to get the leaf extraction and image segmentation which is used to get cucumber leaf disease. The algorithm first used the superpixel segmentation method to divide the cucumber image into blocks, got the edge of cucumber leaf preferably, and proposed a new method to calculate the weights among different superpixels. Then the algorithm used Harris points and convex hull to select saliency seeds. After using manifold ranking to compute the saliency map, the threshold segmentation was adopted on the obtained saliency map to get the binary map. At last, the cucumber disease leaf and background of the original image were separated by adding the binary map to the original image. In order to obtain the disease parts, ExG was used to expand the disparity of green parts and lesion parts and then threshold was used to carry out the segmentation. Finally, the morphological operation was processed in order to obtain fuller lesion. The proposed algorithm was tested on common cucumber disease images. The experimental result shows that the algorithm effectively solves the redundant segmentation and its more accurate with the error rate less than 5% and the average execution time of the algorithm less than 4.000ms in segmentation. From the results it can be concluded that the algorithm verifies the feasibility and practicality of the saliency detection algorithm in processing of disease images. Meanwhile it lays the foundation for the subsequent establishment of the automatic identification system of cucumber disease.

Abstract:As high spatial resolution remotely sensed image be acquired more easily, there is a great potential for obtaining forest inventory automatically and costefficiently. A method was proposed to detect the lichee’s treetop and delineate treecrown. The method can be divided into three steps. In the first step, a 3×3 mean filter was utilized to smooth image, and then the image was inverted through subtracting image from the maximum of the filtered image. The second step was individual tree detection, namely treetop detection. The inverted image can be viewed as a topographic surface, the flow direction grid was built and then the depressions grid was extracted. The depressions distributed on roads and constructions were deleted according to the predefined threshold. Watersheds were delineated to obtain the contributing area of depressions viewing depressions as the pour point. For solving that the multiple depressions were erroneously identified within the same crown, the depressions were deleted if the distance to the nearest depression was less than threshold and the mean value of depression in the filtered image was not the maximum in multiple depressions, the watersheds of multiple depressions were merged. The remaining depressions were viewed as the detected treetop. The third step was to delineate the treecrown by using region growing method. The remaining depressions were used for seed points, crown regions were expanded from depression to surrounding pixels until the difference between the pixel and mean value of depression exceeded the predefined threshold or to the boundary of depression watershed. A 324 pixel×483 pixel Pléiades image with 0.5 m resolution was employed to test the method. A promising agreement between the detected results and manual delineation results was achieved in counting the number of trees and the area of delineating tree crowns. For individual tree detection, the overall accuracy was 87.75%, user’s accuracy was 80.69%, producer’s accuracy was 96.06%; for individual treecrow delineation, the overall accuracy was 78.69%, user’s accuracy was 71.32%, producer’s accuracy was 87.76%.

Abstract:The existence of axillary buds of cherry tomato growing between stem and branches will waste nutrients, resulting in a decrease in production. So they should be removed regularly. At present, they are removed manually, which increases the cost of production greatly. Using robots instead of by hands can reduce the costs. The key issue was the position of cherry tomato buds growing point detected by machine vision. An image processing method based on blue light staining was proposed. A monocular camera assisted with ultrasonic displacement sensor was used for capturing images and getting the 3D coordinate of axillary bud growing point. It was difficult to segment image, because the color of the axillary buds, branches and stems of cherry tomato was same to those of background. A blue LED light source was used to irradiate the axillary buds in order to dye the buds blue. The background was the other tomato plants whose color was green, so it was easy to extract the object from image. The image collected was complete, when the distance between the LED light source and the plant was 13cm. B component image in RGB spatial domain was a gray image and its histogram was bimodal. The gray value was selected as a threshold, and then the image was segmented, the outline of the object could be gotten clearly. However, there were burrs on the edge of the outline, so the gray image should be translated into frequencydomain diagram by fast Fourier transform (FFT). A low pass filter was used to filter out the burrs at high frequency, and the outline at low frequency was retained. The cutoff frequency was set to 28% of the maximum frequency of the image. After the inverse transformation, the burrs could be removed completely. Deformation would occur at the edge of the contour, but it did not affect the subsequent processing. The corner points at both ends of the axillary bud were key feature points. In order to highlight the characteristics of the key feature points, the morphological dilation of image was processed by the 7×7 cross structure element. Then all the corners on the image were found out by using the Shi-Tomasi corner detection algorithm. A discriminant condition was set after analyzing the growth characteristics of cherry tomato axillary buds. Then all the corners were iterated over, if there were two corners in accordance with the discriminant requirement, then the two points were the key feature points, and the midpoint of the two points was the axillary bud growth point. If there was not a couple of corners meet the requirement, then there was no axillary bud growth. If there were two couples corner points meet the discriminant requirement, it showed that there were two buds. There were errors between the axillary bud growth points located by the images and actual points. The error could be accepted since it was within 1cm. 90 images of cherry tomato plants with axillary buds growing were identified, 82 images could be detected the axillary bud successfully, the correct recognition rate was 93.94%. After the removal of axillary buds, stubble length less than 1cm accounted for 88.9%.

Abstract:Due to the differences of soil, climate, varieties in different regions and different planting habits, the rice planting agronomic requirements are different. In order to meet the seeding requirement of conventional rice and hybrid rice simultaneously and to adjust the seeding rate quickly, a combined holetype metering device was designed based on a simple holetype metering device which was developed by South China Agricultural University. The device included holetype shell, holetype roller and adjusting mechanism. A complete holetype was comprised by the label through holes which were uniformly distributed on the holetype shell and the small/big holetype which were uniformly distributed on holetype roller. The shape, size and style of the holetype and the adjusting mechanism were designed and optimized. The reliability experiments of the adjusting mechanism were carried out and the result showed that its structure was reasonable and the seeding rate adjusting process could be completed in 5 s. According to the existed model and theory, the outline dimensions of the holetype were calculated and the results confirmed that the number of the holetype was 8, the big radius was 5mm, the small radius was 4.5mm and the length was 11mm. To further study on the main impact factors of the seeding performance of the metering device, the length and the chamfering angle of the guiding groove and the type of the holetype were selected as the factors of the performance experiment while the conventional rice pregerminated seed Yuxiangyouzhan was selected as the experimental material. The results indicated that the optimal combination parameters were the length of the guiding groove of 6.5mm, the chamfering angle of 60°, the big holetype on the holetype roller with 6.5mm cylindrical hole and the small holetype with 4mm spoonshaped hole. The test results with rotational speed of 50r/min showed that the qualified rate of the seed number per hole of the small holetype was 87%, the seeding qualified rate of the big holetype was 8767%, and the seeding variable coefficients of these towed holetype were 2260% and 2046% which could meet the rice seeding requirement. The correlation analysis showed that the main effect on the qualified rate was the type of the holetype, and the length and the chamfering angle of the guiding groove had effects on the seeding variable coefficients as well. Furthermore, the adaptability experiment was designed by 4 varieties pregerminated rice seeds and 4 rotational speeds (30r/min, 40r/min, 50r/min and 60r/min). The results showed that the combined holetype metering device had good adaptability of seeding conventional rice seeds such as Xiushui 134 and Yuxiangyouzhan, and hybrid rice seeds such as Huayou 14 and Peizataifeng.

Abstract:In order to increase the yield of intertilled crops and enhance the effective utilization rate of fertilizer, a kind of corn automatic hole fertilization control mechanism for intertilled crop was designed. The structure and working parameters of hole fertilization control mechanism were analyzed by soil bin testing. The influence law of parameters of transmission mechanism on the accuracy of fertilizing control was studied. The orthogonal rotation combination method was used with the power output shaft speed, vehicle forward speed and seedling needle height as impact factors, the seedling injury rate and the fitting degree of holes and plants as response functions. The regression analysis of Design-Expert platform and the response surface method were used. The singlefactor and multifactor orthogonal experiment was carried out. The results showed that, when the vehicle forward speed was 1.25m/s, power output shaft speed was 16.5r/min, seedling needle height was 5mm, the fitting degree of holes and plants can reach to 0.796 and seedling injury rate was close to 10%. The optimized parameters can meet the requirements of corn fertilization during seedling stage.

Abstract:At present, the residual film recovery device needs to stop artificially and adjust repeatedly for its groundbreaking depth and rolling speed based on actual situation during the work. It often leads to low levels of mechanization and efficiency. In order to improve intelligence and efficiency of the plastic film recovery unit, the subject takes the elastic tooth residual film recovery device of existing independently developed as the research object. BECKHOFF CX2030 controller and the module were used to collect the data of each sensor in real time and control the operation of the servo motor. Then through the Ethernet interface which based on EtherCAT bus and the GPRS network, it can realize the film shovel automatic lifting adjustment, the film cutting speed online detection, the residual film recovery online visual feedback, the data transmission and monitoring. Through the structure design, theoretical analysis and experimental verification of the intelligent film shovel, the inclination angle of the blade was obtained as 65° to 75°, the safety ground breaking depth was 20mm to 50mm. The application of image technology and computer simulation software was conducive to the realtime feedback of residual film legacy and scientific calculation of residual film recovery rate and operating efficiency. The field experiment in sandy loam soil of potato ridge using the intelligent residual film recovery device based on EtherCAT & GPRS showed that, the effect of the residual film recovery operations was significant in the intelligent level and residual film recovery rate, and the overall level of the device was greatly improved. The successful research and development of the device will greatly promote the residual film recovery to multifunction, intelligence, digitization and automation.

Abstract:With the advancement of the rice cultivation technology and the vigorously promotion of the super hybrid rice, the rice yield is increased rapidly, which proposes higher demand for the performance of the threshing and separating device for the largeamount feeding combine harvester (7~9kg/s feeding amount). When facing large feeding amount, the transition between tangential flow roller and longitudinalaxial flow separating roller will easily get blocking. In order to optimize the structure of newstyle threshing and separating device in oblique tangentiallongitudinal combine and to meet the requirements of highyielding rice harvest at present in China, rice harvest in field was conducted to study the influence of speeds of tangential drum and longitudinal drum, structure form of the tangential drum concave, gap of the conical spiral transition and cover on the performance of total consumption and total loss. The combine was reconstructed based on selfdeveloped oblique tangentiallongitudinal combine and load test system was built for the combine. Orthogonal test with three factors and three levels was carried out in the combine. Optimal parameters were gained by orthogonal test range analysis method. According to the analyzed results of orthogonal test, the rotational speeds of tangential drum and longitudinal drum were 862r/min and 806r/min. The structure form of the tangential drum concave was the type of orientation and separation hole. The gap of the conical spiral transition and cover was 50mm. Under the optimal parameters, the field experiment results were total loss rate of 062% and total power consumption of 40.42kW.

Abstract:According to the existing problems of subsoilers applied in loam soil area in NorthChina Plain, such as high working resistance, high fuel consumption, poor surface flatness and poor soil moisture conservation due to the formation of crack after subsoiling, a polyline soilbreaking blade subsoiler which could effectively reduce working resistance and fuel consumption was designed based on the difference of soil layer thickness and physical properties among plough layer, plow pan layer and subsoil layer. Discrete element method(DEM) was used to establish soil model, the soil particle contact model was set, and virtual simulation parameters of different soil particles in plough layer, plow pan layer and subsoil layer were measured. A virtual simulation experiment on subsoiler performance was conducted using EDEM. As shown in the result, minimum working resistance was detected when the rake angle (θ) of soilbreaking blade was ranged from 40°~45°; minimum power dissipation was obtained when the corresponding shearing angle (φ) to the higher, middle and lower parts of soilbreaking blade were 31°, 36°, 33°, respectively; when comparing with circular arc subsoiler, polyline soilbreaking blade subsoiler resulted in less impact on soil particles, reduced soil disturbance, decreased tractive resistance, significantly improved surface flatness and groove width. The field test indicated that the polyline soilbreaking blade subsoiler effectively decreased soil bulk density and compactness of plow pan layer, hence the working resistance was reduced by 11.52% with better working stability and reliability with comparison to circular arc subsoiler. The rationality and feasibility of threelayer DEM soil model was confirmed through the comparison of field test and virtual simulation experiment, and the model could satisfy the requirement of subsoiler performance experiment.

Abstract:In order to comprehensively evaluate the applicability of plant protection machinery, this paper established the evaluation index system from three aspects：technical index, economic index and operation condition index, used analytic hierarchy process to calculate the results of the expert questionnaires based on the structure model of the evaluation system, and determined the weights of each evaluation index by using judgment matrix and weighted geometric average method. And then it obtained the scores of the third level indicators by the method of test, as well as survey and evaluation of users, and then got the index scores of all levels through analysis and calculation. Finally the comprehensive evaluation index system for the applicability of plant protection machinery was built. This paper evaluated the selfpropelled boom sprayer for example, and obtained the conclusions of the single index evaluation and the comprehensive evaluation. This can provide scientific basis for popularization and application of plant protection machinery by the comprehensive evaluation system, at the same time, it has guiding significance to the optimization and promotion of mechanical performance and operations quality of plant protection machinery.

Abstract:To characterize jet mixture profiles for inline injection of pesticides, twophase flow fields in conventional mixing chambers were investigated under various test conditions. The twophase flow was formed with water mixed with either a watersoluble liquid or a fatsoluble liquid (silicon oil). Test results illustrated that there were limitations for the conventional mixers to obtain uniform mixtures with the fatsoluble pesticide. To overcome these limitations, a new mixing device based on the swirling jet mechanism was conceived and developed to improve the mixture uniformity of water and the fatsoluble pesticide. The swirling jet mixer consisted of a spiral curved shrink tube, a diffuser and a guide vane to accelerate the twophase flow spiral movement and blend the two liquids. A computational fluid dynamics program (Fluent) was used to simulate the flow field inside the swirling jet mixer to optimize its design. The mixture uniformity was evaluated by introducing the uniformity index γa, representing that the two liquids were blended homogenously as γa was 1. Simulated results showed that the γa was 0.9989 across the entire cross sections inside the mixer, confirming uniform mixture profiles with the new mixer design. 〖JP3〗Therefore, the new swirling jet mixer would solve the nonuniform mixture problem associated with conventional mixers and could significantly improve the inline injection technology to reduce pesticide waste.

Abstract:Aiming at the problem of increasing investment cost of knotter production due to difficulty in evaluation of good or bad design after structure improvement or parameters adjustment of the knotter, a kind of virtual knotting method of knotter based on rigidflexible contact dynamics was presented according to the judgment rule of whether the knotter could tie a knot during design phase. The method used the Bushing connection tool under ADAMS to build up dynamic model of flexible rope with large deformation. A complete virtual knotting simulation process of the knotter was implemented by setting up multiple contact constraint between the rope and rigid component of the knotter and applying load to the rope. Rigidflexible interactive mechanical behaviors of tying a knot of the knotter were studied under the action of pulling force of the rope. The comparison analyses between knotting movements of the knotter prototype and virtual knotting results validated the correctness of dynamic model of the rope and simulation model of rigidflexible contact dynamics. It may be regarded as an effective method to evaluate good or bad design and guarantee disposable successful production of the knotter. The effects of the timing sequence difference value φ between the motion of knotting hook and the motion of ropeholding plate on knotting motion of the knotter were analyzed by using the proposed virtual knotting method, which can play visual validation role to judge whether the knotter can knot or tie a good and bad knot after parameters match of the knotter.

Abstract:Peanut breeding in mini area has the characteristics of various varieties, many deals in mini area, little yield and no mixed peanut in mini area and in variety. In order to solve the problems of time and working consuming, lower efficacy and easy to mix in artificial harvesting, an overall scheme of semifeeding peanut picking device was proposed. The structure of staggered matched stack form and the picking parts, including reinforced type, bow tooth and rectangular tooth with adjustable swing diameters were adopted. The structure and parameters of peanuts picking parts were designed. Preliminary experiment was carried out for choosing eventual form of picking parts. The main peanut varieties “huayu30” in Liaoning province were selected as test materials, through orthogonal experiment analysis, the three parameters: picking roller rotating speed, angle of picking roller and overlap distance of picking roller were selected as experimental factors, peanut picking rate and peanut breaking rate were selected as experimental indexes. The structure and working parameter of threshing performance were optimized. Experimental results indicated that picking roller rotating speed, angle of picking roller and the overlap distance of picking roller all had significant impact on peanut picking rate and peanut breaking rate. The most optimum combination index of the picking roller rotating speed was 400r/min, the angle of picking roller was 45° and the overlap distance of picking roller was 10mm. The results of the analysis of the peanut picking rate was 9896% and the peanut breaking rate was 1.03%.

Abstract:A walnut shelling machine with functions of shell crushing, kernel taking and shellkernel separating was designed, which could increase the shellbroken rate and kernelunbroken rate. However, the problems of incomplete brokenshell and unhulling crushedshell were also remained. Thus, the flexiblebelt and differential velocity extrusion system was used to make the walnut kernel out and the effect of that operation was analyzed. The results showed that when the mean crack length was 20mm and the critical external force for crack extension was 191N, the cracks could be further extended. Onefactor test was carried out to explore the influences of the top and low section belt spacing (A), top and low section speed difference (B) and upper belt tension (C) on hulling, and the orthogonal experiment was carried out to analyze the influence of the above three factors. According to the experimental results, the influences on the first grade kernel rate and the second grade kernel rate were C＞A＞B, and for kernelbreaking rate and kernelunseen rate, A＞C＞B. When the top and low section belt spacing was 14mm, top and low section speed difference was 0.19m/s and upper belt tension was 231N, the hulling effect was optimal(hulling rate was 98% and kernelunbroken rate was 93.7%).

Abstract:In order to improve cleaning performance of cross airandscreen cleaning device in maize harvester, through comparing the screening performance of woven screen and shell screen, the structure of shell screen was selected as the main object of study. In order to obtain the optimal parameters of the shell screen, computational fluid dynamics and discrete element method (CFD-DEM) were coupled in the quadratic orthogonal rotationalcombinational simulation tests. Objective indexes were screening efficiency of shell screen and cleaning rate of grain. The factors were the length and height of screen hole and the space between screen holes. The test data were analyzed by the response surface method and the regression mathematical models were multiobjective optimized by using Design-Expert software. Simulation results showed that height of screen holes had the most significant effect on the indexes, followed by the space between screen holes, then the length of screen holes. The optimized parameters were the length of screen hole of 21.68mm, height of screen hole of 10.86mm and space between screen holes of 55.04mm. The results of verified test showed that screening efficiency was increased from 81.79% to 89.91% and the cleaning rate of grain was increased to 9728%, which were consistent with the simulated results. The performance of the cleaning device was enhanced.

Abstract:In order to solve the existing problems of the leakage and dropping of fruit in the process of peanut harvest using machine, this paper designed the twicereceiving device on 4HBL-2 peanut combine. The device is mainly composed of twicereceiving shovel, conveying device, fixed frame and transmission chain, etc. It can finish the process of twicereceiving, cleaning and gripping fruit when harvesting. Besides, this paper designed and did analysis on twicereceiving device and determined the optimal structural parameters and working parameters: the twicereceiving installation angle was 20°, the twicereceiving chain conveyor speed was 12m/s, the bar was 10mm. When the unit speed was 0.6m/s, the peanuts average net fruit rate was 90.16%, the average leakage rate was 0.12%, improving the quality of peanut harvester, reducing the labor intensity of the peanut twicereceiving and operating costs. This equipment will give theory and technical support for the design of twicereceiving multifunction peanut combine. Others, the technical level of peanut combine in China has been greatly improved, and has developed many machines, such as: 4HB-2A, 4HBL-2 and 4HL-2, etc. Those machines can complete the work of mining, picking, soilclearing, fruitpicking, cleaning, and collecting, etc. But the problems of leakage off of peanut fruit in the process of peanut harvesting, there is an average of 5%~8% of the losing. Besides, the cost of twicereceiving of artificial is high and there is no research of twicereceiving on peanut combine in China or at abroad. The main reasons of the existing peanut combine on leakage and off are: first, because of the high maturity of peanuts, the peanut roots and fruit node relay cant meet the requirements of harvesting; second, some peanuts in the process of soilclearing felloff on the ground. So the research of this twicereceiving device of peanut combine has important significance.

Abstract:A lot of study has shown that the distribution of vertical stress in soil just below a loaded tyre is not uniform, and the stress distribution as well as the size and form of the tyre-soil interface are decisive for the topsoil compaction. The distribution of vertical stress was measured in the contact area for three different tyre inflation pressures (85, 100, 120kPa) and load of 21kN. The study took place on a sandy soil in Zhuozhou city, Hebei province. The effects of three different inflation pressures were tested in a randomized block design with three replicates. The vertical stress was measured with load cells located in about 0.1m soil depth. The collected data in the experiment was used to calibrate and validate the FRIDA model. The validated FRIDA was used to predict soil-tyre contact area and the stress distribution across soil-tyre interface. The validation results showed that the RMSE(root mean square errors) and Bias (standard deviation) for soil-tyre contact area were ranged from 0.022m2 to 0.013m2 and from -0.19m2 to 0.019m2, respectively. The decision coefficient of contactarea between the tested and simulated values was 0.948. The relative errors (RE) of measured and predicted values of peak stress and mean stress were generally less than 0.1. Results showed that the FRIDA model could predict the soil compaction problems in sandy soil of north China. The FRIDA model was used to simulate the soil-tyre contact properties and stress distribution at different tyre inflation pressures. At the recommended inflation pressure, tyre displayed a stress distribution across the width of the wheel that could be evaluated as optimal with regard to a minimized topsoil compaction. The FRIDA model seems very well suited for describing the stress distribution at soil-tyre interface, but should be validated with other soil conditions.

Abstract:At present, Procambarus clarkii processing enterprises mainly remove shrimp intestines manually. The problems of large labor intensity, low production efficiency and easy to pollution were existed. A continuous clamping and pulling intestine removing machine for Procambarus clarkii was designed. After the headremoving process, the shrimp tail was put in the clamping device and moved with it at the same time. The upper cover of the shrimp tail was closed with the action of the clip cover guide rail and the spring. When the shrimp tail moved to the intestine removing device, the shrimp sausage component was driven by chains. The tail fan got into the intestine removing clamp mouth along the tail fan guide. The intestine removing clamp mouth first clamped the tail fan, and then pulled it out with the shrimp intestines. The key parts of continuous clamping and pulling intestine removing machine were descripted, including shrimp intestines institutions, shrimp intestines guide rail, conveyer, shrimp tail clamp lock, shrimp intestine cleaning, etc. The transmission system design and prototype test were also accomplished. Though adjusting the relative position of the shrimp tail clamp and intestinal clamp mouth, different sizes of Procambarus clarkii could adapted well. Through the prototype test, the following result could be got as intestine removing rate of 91.0%, net rate of 86.5%, production efficiency of single mechanism of 1.4 shrimp per second.

Abstract:Rill erosion is one of the most important slope erosion in loess area, and soil detachment process is an important link of rill erosion. However, the existing studies only are based on a single soil conditions, while the simple relationship between soil detachment rate and water dynamics cannot fully reflect the coupling mechanism of the soil detachment rate under different types of soil. More importantly, the existing research involves little on the relationship between the detachment rate and bed surface morphology. The article adopted the combination of six kinds of slope gradients (2°, 4°, 6°, 8°, 10° and 12°) and five discharges (8L/min, 16L/min, 24L/min, 32L/min, 40L/min) to do scouring experiment. The results showed that: soil detachment rate had power function relationship with discharge and slope, and slope had a greater influence than discharge; Different types of nondimensional soil detachment rate and nondimensional unit stream power had zoned phenomenon with nondimensional flow velocity which showed that soil detachment had other influence factors except diameter of particles; Nondimensional soil detachment rate and nondimensional shear stress doublelog function had a linear increase relationship, and there was no partition; Soil detachment rate had a trend of increase power function with the increase of down hole development coefficient, and the soil detachment rate had a power function decreasing trend with the L/H increases. This results show that the more complex bed surface morphology increased, the more mature down hole developed increasingly and the more intense soil detachment is. The results of the study have some theoretical value to the mechanism of sediment transport on rill flow erosion, moreover it has a certain guiding significance on loess slope surface soil detachment control and ecological restoration.

Abstract:In view of the planting characteristics which are mainly consisted of small farmers and some large growing farmers in China, the solar energy technology was combined with spray irrigation technology together. In addition, a light and small solar energy canal feed sprinkler irrigation machine was developed. An autonomous navigation system was developed on selfdeveloped solar energy canal feed sprinkler machine. Under different working conditions, angle sensor and electronic compass were adopted for the autonomous navigation test. The precision irrigation control system and spraying domain control system were integrated to realize automatic control of sprinkler machine. According to the attitude information of the sprinkler machine acquired from angle sensor, electronic compass and wheel speed sensor, a fuzzy controller for autonomous navigation was built. By adjusting the speed of driving wheels on both sides, a closeloop feedback control system of steering was also built. Besides, to verify the navigation accuracy of the system, a tracking experiment was carried out. The results indicated that the lateral tracking error could be well eliminated with travelling speeds of 0.5m/min and 1.0m/min, which showed that the sprinkler machine was provided with high reliability and stability. In other words, the control system can well meet the demand of spraying work.

Abstract:In order to investigate the fractal characteristics and influence factors of irrigation water use efficiency in different scales irrigation areas, the measuring results of irrigation water use efficiency in 115 different scales irrigation area were selected as samples during 2009—2014. The fractal characteristics of above samples were studied by using the method of rank-size distribution, and the influence factors of irrigation water use efficiency of Heilongjiang province were analyzed by using principal component analysis. The result showed that the fractal dimension value D of irrigation water use efficiency of Heilongjiang province was ranged in 5.26~6.25 in 2009—2014, and the distribution of irrigation water use efficiency changed from multifractal structure to single fractal structure. For the largemiddle scale irrigation area (D1=4.58), irrigation water use efficiency was the maximum of 44.44%. For the miniature irrigation area (D2=4.79), irrigation water use efficiency was the maximum of 53.81%. For the pure well irrigation area (D3=6.98), irrigation water use efficiency can reach maximum of 70.41%. For the whole province (D=5.13), irrigation water use efficiency can reach maximum value of 57.03%. In the influence factors analysis for irrigation water use efficiency of different scales irrigation area, the channel lining rate and engineering equipment rate were the most two influential factors to irrigation water use efficiency of largemiddle scale irrigation area. To miniature irrigation area, the influence of the channel lining rate was the most, and the influence of the ratio of evaporation to transpiration was the least. Field leakage was the most influential factor to irrigation water use efficiency of pure well irrigation area. The research results provided a theoretical basis for the balanced promotion of irrigation water use efficiency in Heilongjiang province.

Abstract:In order to understand the relation between the developing process of rill erosion and flow shear stress, the paper simulated the developing process of rill erosion applying hydrodynamics software ANSYS CFX (version 15.0.7) to explore the distribution of flow velocity and shearing stress in the rill section. Based on flume experiment, 6m long flush tank was used and rill development in 8 sections was measured. The experimental flow rate was 800L/h. The paper anaylized the characteristics of flow velocity and sheer stress combined with the measured value of rill section and it is a supplement in computing hydrodynamics of the fracture mechanism of rills under water flow. The results showed that the rill section average flow velocity was 0.71 times of the surface velocity, the correction coefficient was 0.78 with the dye method to determine the rill flow velocity when using the way of CFX numerical simulate pattern method. Rill section shape affects the magnitude of shear stress. The sheer stress value of broadshallow section was less than the narrowdeep section which is between 1.41~2.10Pa. The shear stress determined the rill development, and the point sheer stress distribution of rill section was normal distribution. The point sheer stress of rill section was consistent with the rill development and sheer stress was tightly correlated with the development of each point in the section.

Abstract:Soil nematode and microbes are essential and very sensitive to any upsets in terrestrial ecosystems. In order to reveal the tendency of soil quality of wolfberry (Lycium barbarum L.) orchard, make the origin of L. barbarum as the objective region, different stand ages of soil were selected in wolfberry orchard. The objective of the study was achieved by nematode and phospholipid fatty acid (PLFA) biomarker analysis of soil samples from L. barbarum orchards in the objective region. The change rule of soil nematode and microbial community diversity with the change of season, soil layer and stand age was analyzed. The results showed that the abundance of nematode was increased and then decreased in 0~20cm of soil, with the highest nematode at the stand age of 6. The proportion of bacterivores was the highest (57.23% and 61.19% in summer and autumn, respectively), and plant parasites nematode was next, fungivorous nematode and predatorsomnivore had the lowest abundance. Plant parasites nematode was relatively higher at 20~40cm than that at 0~20cm. The average concentrations of total and bacterial PLFAs in the surface soil were initially decreased and then increased, and the highest microbial PLFA concentrations were obtained in 9th year. The tendency change of total and bacterial PLFAs were similar to nematode abundance at 20~40cm in summer. With longer stand age, Shannon diversity index (H′) and richness index (SR) of nematode were increased and then decreased, however, H′ and SR of microbial were decreased, and dominant index was increased. The change tendency of abundance, H′ and SR of soil nematode were similar to soil microbial. There was significant negative correlation between soil pH value, EC, microbial and bacteria PLFA. The organic matter, total nitrogen and available P were significantly positively correlated to the abundance of nematodes and concentration of microbial PLFA, respectively. Total abundance of nematode, bacterivores and bacteria, fungi and actinomyces PLFA were significantly positively correlated. On the whole, the season, layer and stand age had different effects on the nematode and microbial community, and the stand age had the least effect; the season, soil layer and 〖JP3〗stand age had more significant effect on microbe than nematode. Furthermore, the microenvironment of soil was improved and then declined gradually as the stand age increased in the same season as well as the soil layer.

Abstract:In the ion selective electrode (ISE) based soil nitratenitrogen (NO-3N) detection, coexisting chloridion (Cl-), changing of temperature and soil moisture are the primary interference factors. Aiming at improving the accuracy and timeliness of NO-3N detection on site, measurement models for eliminating interference factor’s effects were studied. First, theoretical analysis of modeling and fresh field soil immediate detection was carried on. Modeling theoretical analysis was based on ISE detection principle and multivariate calibration in chemometrics. And to improve timeliness of soil NO-3N detection on site, how to detect fresh field soil immediately and calculate NO-3N content were discussed. Second, two groups of experiments were conducted. One was ISE potential signals collection of mixed solutions with different concentrations (NO-3 and Cl-) at various temperatures measured by detection instrument. According to modeling dataset of ISE potential signals, interference factor’s effects were discussed and three kinds of measurement models were built, including unitary linear regression model of 25℃(base model), multivariate linear regression model of 25℃(simultaneous detection of NO-3 and Cl-), and multivariate temperature correction model of 5~30℃(simultaneous detection of NO-3 and Cl- at changing temperature). And the accuracy of three models were verified and compared according to validation dataset. The other one was NO-3N content detection of fresh field soil measured by corrected and uncorrected NO-3N content conservation equation. The results showed that when Cl- existed and environment temperature changed, multivariate linear regression model of 25℃ was the best (relative error of NO-3 and Cl-  was respectively less than -8.37% and -12.03%). Besides, corrected soil NO-3N content conservation equation can reduce the error caused by soil moisture.

Abstract:Leaf angle distribution (LAD) can be used to describe the canopy structure of vegetation completely, such as crops, trees and grass. It’s one of the important parameters to quantitative description of vegetation canopy structure. At the present, there are few studies used the spectral data to inverse LAD, and results of the most existing studies of mean leaf tilt angle and leaf angle distribution were the locational inversion. Therefore, this study set the study site in five counties of Baoding City, Hebei Province, using terrestrial laser scanning (TLS) to acquire the leaf angle distribution data of maize. Combining the Landsat8 remote sensing data, firstly, the principle component analysis was taken to extract the principle information of measured leaf angle distribution of maize. Secondly, the back propagation artificial neural network was taken to model the relationship of principal information and spectral data. Then, the model was used in the whole study area to accomplish the upscaling transform. Finally, the upscaled mean tilt angel (MTA) was calculated based on the predicted LAD by principal component inverse transformation, in order to quantitate the leaf angle data. The cross validation result showed that the accuracy (R2) between upscaled MTA and measured MTA was 0.7862, and the mean square root error (RMSE) was 3.04°. Consequently, it shows that this method can realize the aim of LAD upscaling.

Abstract:To investigate the effects of water regimes on yield formation, photosynthetic characteristics and transpiration efficiency of rice plants in arid region, plot experiments were conducted in 2011 and 2012 in Shihezi City with three water treatments, including flooding irrigation (W1), controlled irrigation technology (W2) and aerobic rice (W3). The results showed that there was no significant difference for net photosynthetic rate (Pn) in W1 and W2 treatments before anthesis, but W1 treatment was 11.29%~20.91% higher than W2 treatment, and 38.65%~52.03% higher than W3 treatment after anthesis across both years. Further analysis indicated that little difference of the parameters of Pn, carboxylation efficiency, saturation light intensity, and compensation light intensity were existed in W1 and W2 treatments in saturated soil moisture, the lower Pn in W2 and W3 treatments than that in W1 treatment was mainly due to significantly decreased Pn in W2 and W3 treatments when soil water content was unsaturated in 2011 and 2012 （p＜005). Moreover, the diurnal changes of Pn was higher in W1 treatment than that in W2 and W3 treatments during whole observed times, and the difference was greater on forenoon (before 12:00) than on afternoon (after 14:00) among treatments. Finally, the grain yield in W2 and W3 treatments only decreased by 4.43%~18.72% and 31.23%~39.45% when compared with W1 treatment considering both years. The transpiration efficiency in W2 treatment was always significantly greater than that in W1 and W3 treatments during whole growth stages in both years （p＜005). Generally speaking, the W2 treatment performs high grain yield and high water use efficiency in arid region, meanwhile, the grain yield in W2 treatment could be increased when improving photosynthetic produce ability in the afternoon at grainfilling stage.

Abstract:In order to reveal the further influence mechanism and law of intermittent infiltration of surge irrigation,based on the theory of Green-Ampt and Philip models, this paper proposes the concept of dividing the infiltration and wetting zone of the second water supply period and later period of water supply into two zones. The two zones were humid region of gravity potential and matrix potential. And the infiltration of concept characteristics of two zones was described. Building a mathematical model of the increasing capacity of volumetric water content by the inner relationship between the parameters of the two models (Green-Ampt and Philip models) and based on the linear pattern characteristics between the increment of soil volumetric water content and cumulative infiltration capacity, the water movement parameters of different water supply periods were determined. One of the water movement parameters was suction value of wetting flog hf and another was characterized saturated hydraulic conductivity Ks. The value of hf of intermittent period has the decreasing trend with the increase of the number of cycles. Finally, using the improved model to compare the calculated cumulative infiltration capacity and wetting front with measured data, a higher fitting precision was acquired. Compared with the measured data, the overall average relative deviations were 3.6% and 8.6% respectively. The improved model has good applicability. Hence a more accurate description of the mechanism of intermittent infiltration of surge irrigation could be described by this model which provides theoretical basis for the reasonable design of surge flow irrigation technology.

Abstract:Crop planting structure was generally considered to be basic data for assessment of water productivity and agricultural irrigation water management. And the adjustment and spatial distribution of crop planting structure was closely related to the water consumption and the improvement of soil and water environment, especially in large irrigation district of north China. To deal with water resources crisis caused by climate change and intensified human activities in Hetao irrigation district in north China, many watersaving irrigation projects were taken to solve the problems since 1999. In recent years, net water diversion and ground water depth tended to decrease obviously, and the irrigation efficiency of irrigation districts tended to increase which showed good result of water conservation projects. The purpose of this study was to discover the changes of planting structure adjustment, the characteristics of spatial distribution, the effect on agricultural water consumption changes and the response to the distribution of groundwater. A data fusion approach (Enhance spatial and temporal adaptive reflectance fusion model, ESTAFM) was applied to generate synthetic Landsat7 ETM+ data with MODIS and construct the high spatial and temporal NDVI data sets. And major crop types were extracted successfully by spectral matching technique (SMT) in 2015. The positional accuracy of maize, sunflower, wheat and interplanting were 95%, 88%, 91% and 90% respectively and the historical change of total area of different crops was consistent with the statistics data. Using this method, the planting structure of Jiefangzha irrigation area, the second largest irrigation field in Hetao irrigation district, was effectively extracted over the years and its temporal and spatial variation and correlation with the distribution of groundwater depth were acquired. The result showed that the area of maize and wheat was increasing, the sunflower was decreasing firstly and later converted into an upward trend,and the interplanting area was declining year by year. The factor for the changes of crop planting structure mainly attributed to the market demand and national policies. For spatial distribution, sunflower concentrated in the region with severe salinization in shallow groundwater level, on the contrary, the maize, wheat and intercropping concentrated in the region with slight salinization in deeper groundwater level. The spatial distribution of crop planting was not only closely related to water and soil environment but also physiological characteristics of crops. Although net water diverted from Yellow River decreased year by year, the agricultural evapotranspiration showed an upward trend which caused by planting structure, especially the variation of maize. The groundwater depth declined from 1.76m to 2.33m and the water and soil environment was improved which was contributed to the good performance of watersaving projection.

Abstract:This study was about crop decomposition characteristic changes of corn and bean residues (with different water conditions and C/N ratios) decomposition in the fields of three land uses (vineyard, peach orchard, farmland), using nylon mesh bags method and thermogravimetry (TG), which can provide a scientific basis for the rational use of straw resources. The results showed that at the early stage of the decomposition (0~20d), the decomposition rate was more than 20% and the decomposition rate of bean straws was faster than that of corn straws. On 0~90d of the decomposition, they were relatively stable. Then the decomposition rates increased to 60%~70% at the end (300d). In TG-DTG curves, the mass loss of 200~300℃ stage（20%~30%） was caused by the corn straws during the decomposition (20~45d). At the end of decomposition, the 300~400℃ mass losses of bean straws were significantly higher than those of corn straws. The values of 600~700℃ in TG and DTG curves at the end of the decomposition (300d) were about 6%. The decomposition rates and percentages of fixed carbon and volatile matters were significantly different between fresh and dry treatments, corn residues and bean residues, and low C/N ratio and high C/N ratio treatments （P < 0.05). While, there were no obvious differences in three different land uses （P > 0.05). The decomposition rates and fixed carbon contents were significantly positively related to soil temperature and precipitation （P < 0.05), and volatile matters were negatively correlated with soil temperature and precipitation （P < 0.05). Corn and bean straws in soils could increase the carbon content. Type, C/N ratio and water condition of crop residues, and soil temperature and precipitation could affect the crop straw decomposition in the soil.

Abstract:A laboratory scale experiment of chicken manure digestion cocomposting was carried out using a reactor system with oxygen monitoring and feedback control. The physiochemical indexes, including temperature, oxygen concentration, volatile solid content (VS), moisture, C/N, pH value, EC, cellulose, hemicellulose, lignin, biological index, and main gas emissions (CH4, NH3 and N2O) were monitored and analyzed, respectively. Physical, chemical and biological indicators presented a good dynamic corresponding relationship, and the degradation of cellulose materials mainly appeared at the middle and later periods of aerobic cocomposting. Temperature and oxygen concentration had an effect on gas emissions: high temperature promoted the emissions of NH3 and N2O with a significantly positive correlation (r=0.378; r=0.695), high temperature and oxygen concentration decreased the emission of CH4 with a significantly negative correlation (r=-0.470; r=-0.494). Gas emissions can be controlled through adjusting the levels of composing oxygen concentration and temperature. Multiparameters characterization and correlation analyses can provide theoretical and methodological basis for process optimization of chicken manure and digestion co-composting. However, characterization and the coordination mechanism should be explored in depth on fermentation performance and gas emissions combining with comprehensive multiindexes during and digestion cocomposting in future studies.

Abstract:The installation of artificial sludge blanket layer to the anaerobic ponds has accelerated the sludge formation rates, shortened the cultivation time and improved the sludge activity. It also enhances the operability of the formation process of the anaerobic granular sludge.The impacts on the formation of anaerobic granular sludge from the artificial sludge bed and the mechanisms of granular sludge adsorption were investigated. Scanning electron microscope (SEM) was used to measure the shapes of the anaerobic granular sludge and furthermore determine their fractal dimension. A granular sludge adsorption model was developed based on the distribution patterns, average particle sizes and water contents of the granular sludge. Results show that when attached to the artificial sludge blanket layer, the anaerobic granular sludge was evenly distributed across the layer, with particle sizes between 4mm and 5mm, and made up to 80% of the total sludge in the system. Under the SEM, their shapes were clearly observed and their fractal dimensions were between 2.68 and 2.83. Results also show strong stability of granular sludge on the artificial sludge layer. When the hydraulic loading rate reached 5kg/(L·d), they still maintained an average concentration of 5.84kg/m3. Results from the granular sludge adsorption model indicated that the internal circulation of the sludge inside the reaction pond can stimulate the formation of the anaerobic granular sludge. Peak adsorption capacity of the anaerobic granular sludge was achieved when the concentration ratio of upflow/downflow sludge fell between 0.8 and 0.9. This study will provide a reference to the formation of anaerobic granular sludge for the industrial treatment of wastewater with high organic concentrations.

Abstract:Lactobacillus extracellular proteins are key molecular factors in promoting the probiotichost crosstalk and signal transduction. Their extractions and identifications could contribute to unravelling the probiotic molecular mechanisms such as adhesion to intestinal surfaces, modulating immune response and enhancing antagonism towards pathogens. A protocol based on trichloroacetic acid (TCA)acetone precipitation of proteins was presented and optimized. The method was tested on seven Lactobacillus strains after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The extracellular proteins secretion capacity of L. paracasei SW2 in different growth phases was studied and some protein bands were selected for identification by tandem MS. The extracellular proteome of L. paracasei L14 were analyzed by 2-D electrophoresis (2-DE). The results showed that the final concentration of 6% TCA was the most suitable for extracting extracellular proteins from lactobacilli. More extracellular proteins could be extracted in the stationary phase than midexponential growth phase. Three of extracellular proteins extracted from L. paracasei SW2 were successfully identified. The extracellular samples extracted from semidefined medium (SDM) could be analyzed by 2-DE. 130±10 spots, corresponding to about 46% coverage of the predicted secretome of L. paracasei, were detected in the 2-DE map of L. paracasei L14 extracellular proteome. In conclusion, this study preliminarily established the extraction method and 2-DE analysis system of extracellular proteins from lactobacilli and paved the way for a more comprehensive insight into relevant research.

Abstract:With the improvement of people’s living standard, people are more and more concerned about the quality of fruits and vegetables during freezing and cold storage. However, fruits and vegetables are constant in the process of freezing-thawing during freezing and cold storage. Therefore, it is very important to research the phase transition of fruits and vegetables during the freezing-thawing process. The phase transition of fruits and vegetables in the freezing-thawing process was studied by using red grape as the test object. Grape pulp was tested with different rates, frequencies, time intervals, rate gradients and the rates through maximum ice crystal generation zone during the freezing-thawing process by DSC. By analyzing the heat flow curve in the experiment, the effect of freezing-thawing process on grape sample under different conditions was found. The greater the freezing rate was, the lower the freezing point temperature was, the shorter the time during the freezing process was. With the increase of the rate, the peak temperature of phase transition, the end point of phase transition temperature and the latent heat of phase change all increased during the process of thawing. In the process of temperature change from 2℃/min to 20℃/min, the latent heat of phase change increased 1.79 times, the peak temperature of phase transition increased 0.94 times, and the end point of phase transition temperature increased 5.07 times. The study provides a basis of quality recovery after freezing-thawing process for fruits and vegetables.

Abstract:To explore a rapid method for detecting moisture content of cow’s milk, a network analyzer and an openended coaxialline probe were applied to measure the dielectric properties (relative dielectric constant and dielectric loss factor) of 105 milk samples over the frequency range of 20~4500MHz at room temperature (25±0.5)℃. The low linear correlation coefficient between the moisture content and the permittivities at a single frequency of used milk samples showed that it was difficult to predict the moisture content of milk using a single permittivity value. Therefore, the dielectric spectra combined with chemometrics were used to determine the moisture content of milk. All samples were partitioned into calibration set (75 samples) and prediction set (30 samples) by using set partitioning method based on joint X-Y distances. Fifteen characteristic variables that predicting moisture content of cow’s milk were selected by successive projection algorithm from full spectra. The generalized regression neural network, support vector machine and extreme learning machine models were established to predict moisture content of milk (87.28%~91.30%), based on the original full dielectric spectra and characteristic variables. The results showed that the extreme learning machine model established using the characteristic variables selected by successive projection algorithm was the best model in determining moisture content of milk, with the correlation coefficient of prediction, rootmeansquare error of prediction, and residual prediction deviation of 0.988, 0.119%, and 6.723, respectively. The study indicates that the dielectric spectra combined with chemometrics could be used to detect moisture content of milk. The research is helpful to develop a new milk moisture detector which could be used in situ or online detection.

Abstract:Cultivated land（CL） resource is an important resource for human survival and development, and it bears the function of ensuring food security and social stability. The research on the value evaluation of CL resources provides a theoretical basis for the protection of CL, and has important practical significance. With the scarcity of ecosystem services become more and more prominent, the ecological value (EV) evaluation of CL has received unprecedented attention.This paper explored the research advances and perspectives of evaluation on EV of CL. Firstly, the current value of CL classification system and the connotation were summarized. The research of the CL resources value has experienced the development process from the value of no value to a single value then to the comprehensive value accounting at home and abroad, and scholars focused on how much food and how many people will be able to produce, and gradual transition to the economic output value of the cultivated land, the social security function and the value of ecological services, the EV of CL were defined on the basis of the study above. Secondly, the accounting methods of EV of CL were summarized at home and abroad, including equivalent value correction method, substitute market method and simulation market method, and the advantages and disadvantages of each method were summarized. Finally, this paper put forward the focus of future research about EV evaluation of CL，including the follows: research on EV system of CL, the EV of CL evaluation method research, the EV refinement and evaluation of CL and in the ecocompensation for CL in applied research.The research results and conclusions had great significance for the theory and method of the EV evaluation of CL.

Abstract:The occurrence of agricultural diseases has been one of the restrict factors of sustainable agricultural development for a long time, and agricultural diseases early warning technology gradually becomes a hot issue in China and abroad. Based on the literature review, the important meaning of agricultural diseases early warning technology for agricultural development was presented. This article expounded the characteristics and classification of agriculture diseases early warning firstly. And then a systematical analysis and discussion were carried on the key technologies for agricultural diseases early warning information acquisition, mainly summarizing the internet of things and sensor technology, 3S technology, spectrum technology and pathogenic microorganism examination technology. And also an introduction of agricultural diseases early warning information processing technologies was made, such as image processing technology, expert system of disease early warning and disease prediction technology. Finally, the conclusion of the whole article was obtained. The results indicated that the integration and combination of mutitechnology would cover the whole agricultural diseases early warning area and get a higher accuracy of disease early warning；the acquisition of agricultural information was becoming precision and extensive; the early detection，diagnose and warning of agricultural diseases would be a new development direction; the agricultural disease early warning systems and equipment would be developed with lower cost; the realtime and online agricultural diseases automatic early warning will be an important research direction.

Abstract:In order to provide more specific knowledge and technology of plant field, the main task of KG (knowledge graph) is to extract a wealth of concepts and relationships. Due to the relation extraction is the most difficult in KG construction, this paper makes use of ontology learning, and proposes a nontaxonomic relation learning method to obtain representative concepts and their relations from unstructured and semistructured texts of Baidu Encyclopedia entry content by using lexiconsyntactic patterns based on dependency grammar analysis. Moreover, the methods of adding constraint models and words filtering were adopted to build heavy weight ontology automatically based on a lightweight ontology and greatly improved the precision of the relation extraction. The approach established a concept structure from the plant domain corpus, ameliorated the discovery of the most representative non-taxonomic relation, and formalized them in the standardized OWL 2.0. A set of experiments was performed using the approach implemented in the plant domain. The results indicated that extraction by patterns should be performed directly after natural language processing, which has a comparatively high accuracy compared to the former algorithms, and this approach can extract non-taxonomic relations with high effectiveness, which lays the foundation for KG construction of plant field.

Abstract:In the ecologically vulnerable area which locates in northwest arid and semiarid areas, ecological land is the important guarantee to maintain the security and stability of regional ecological environment. Studying the simulation of ecological land use change is of great significance. Accordingly, based on the typical ecologically vulnerable area—Dengkou County, this paper simulates ecological land use evolution of Dengkou County, using the four remote sensing image interpretation data of 2002, 2007, 2012 and 2015. Taking ecological ecoresistance barriers and EnKF-MCRP model into account, an ecological resistance surface was built. The EnKF-MCRP model was constructed to simulate the evolution of ecological sources considering the ecological sources change, ecological source level, distance and base surface resistance characteristics. The results showed that the combination of data assimilation and EnKF-CA/Markov model made a total accuracy of 82.4%, by using ensemble Kalman filter, the model can accumulate less errors and improve the accuracy of simulation, i.e., data assimilation can reduce the accumulation of errors. According to the expandability, ecological sources of Dengkou County were divided into five grades, of which the spatial layout of 3, 4, 5 grades formed the northeastsouthwest and northwestsouthwest pattern of desertification prevention. The building of EnKF-MCRP which takes the ecological source evolution into consideration made the highest precision. And the area of ecological sources and spatial distribution were the closest to the reality, of which the variance met 0.4. Different levels of ecological sources and ecological barriers were used to modify the model, which can improve the accuracy of the simulation results. This study could provide a scientific basis for the current and future ecological land planning and management.

Abstract:Daily behaviors are the important indicators of health status for calves. The suitability of using behavioural changes to provide an early indication of calf’s disease was studied. The possibility of achieving a realtime analysis of a number of specific changes in behaviours, such as lying, standing, walking, running, and jumping, is crucial for disease prevention. Considering the limitation for sensing animal behavior by contacting device and in order to improve the welfare of calves, a method based on video analysis was studied and applied to recognize calf basic behaviors. Firstly, a looping algorithm based on maximum connected region was proposed for fast detection of calf target under complex environment. Secondly, a realtime model was built to renew the background and detect the calf’s target quickly and accurately. Thirdly, the position of the centroid, the ratio of the height and width of the target outline, and differences of the centroid moving curve were extracted as the features of behaviors. These features could be the characterizations of the internal properties of behaviors constituted the sequence structure of calf behaviors. Finally, a classifier based on structure similarity of behavior features was designed to recognize basic behaviors of the calf. By testing 162 videos, the results demonstrated that the recognition rate of lying, standing, walking and runjump were 100%, 96.17%, 95.85% and 97.26%, respectively. On the basis of these research outcomes, the proposed method is feasible for computing calf behavioural indices and the realtime detection of behavioural changes, and also lays a foundation for recognizing and understanding senior behaviors of large animal.

Abstract:In recent years, the phenomenon of the landscape degradation in the river basin has been more and more serious because of over ecotourism, and the forestry visualization technology provides important reference for ecosystem restoration and landscape optimization decision, therefore, it is necessary and practically significant to research the visual simulation of vegetation growth in the river basin. This paper presented the case of pterocarya stenoptera in aquatic-terrestrial ecotones in Lijiang River, and found that total nitrogen content of soil plays a critical role during its growth after analyzing the correlation between soil sample and growth data. Based on this finding, the modified Hegyi’s simple competition index model with added nitrogen factors was adopted to the single tree growth model for pterocarya stenoptera stands built in Lijiang River, then diameter distribution model and random algorithm were applied to whole stand model. In the process of simulation, the information of location and diameter at breast height distribution of pterocarya stenoptera in the plot was confirmed by the trees distribution model first; the next step, the height and the crown of each pterocarya stenoptera were simulated according to the fitting relationship between tree height and diameter at breast height, crowns with diameter at breast height and the diameter at breast height of each pterocarya stenoptera were measured, and then, the growth of pterocarya stenoptera was simulated by iterative execution of the growth model using the data got before; after that twodimensional simulation with different soil nitrogen contents was achieved by implementing C# programming language and GDI+ technology, and then the dot and the circle in twodimensional simulation would be mapped into specific pterocarya stenoptera model on 3D Max; finally the threedimensional visual simulation of the growth of pterocarya stenoptera in Virtools platform was achieved. The result showed that a significantly positively relationship existed between diameter at breast height growth and soil total nitrogen content of pterocarya stenoptera, and the correlation coefficient was 0.749; a significantly negative relationship exists between competition index and diameter at breast height growth, and the correlation coefficient improved from -0.621 to -0.657 with the competition index model improved; the error rates were 6.25% and 11.9% respectively when fitting the diameter distribution of pterocarya stenoptera in the simulation and the decision coefficient of diameter at breast height growth model reached 0734. It’s found that adopting modified Hegyi’s simple competition index model and random algorithm had strong applicability and higher fidelity for pterocarya stenoptera growth simulation in aquatic-terrestrial ecotone. The originality of this paper is to adopte modified Hegyi’s simple competition index model with added nitrogen factors, with the help of Virtools platform, to lay the foundation for further development of humancomputer interaction and real time walkthrough. In this article, it provides theoretical basis and reference for the vegetation restoration and succession simulation in Lijiang River watershed, and presents a feasible research idea and implementation method for the forestry visualization research by visualization simulation of pterocarya stenoptera growth in the Lijiang River watershed.

Abstract:The observation data of LAI-2000 and vegetation index was generated by satellite remote sensing data of HJ, combining three kinds of commonly used regression model. LAI (Leaf area index) inversion model was constructed according to growth period, growth stage and threshold boundaries of summer maize, respectively. The optimal LAI inversion model was acquired based on the above three modes. The summer corn LAI scatter grams of the vegetative growth period, the tasseling stage as well as the reproductive stage were generated after verification and evaluation of the model reliability. The productions of MODIS LAI (MOD15A2) were verified by LAIHJ based on the inversion of model HJ image. According to the survey, except HJVI, during the whole growth period of summer maize, a linear model of RVI with LAI was regarded as the best fitting model (R2 = 0.662); during the vegetative growth period, a linear model of OSAVI with LAI was regarded as the best fitting model (R2=0.724); at the tasseling stage, index model of OSAVI with LAI was regarded as the best fitting model(R2=0.749); at the reproductive stage, a linear model of NDVI with LAI was regarded as the best fitting model(R2=0.700). The correlation of HJVI and LAI at the growth period achieved to 0875, and the correlation at different growth stages with LAI is higher than the other vegetation indexes (during the vegetative period, R2=0.769; at the tasseling stage, R2=0.783; at the reproductive stage, R2=0.703). EVI is the best index when LAI is less than 3 (R2=0.358), while OSAVI is the best when LAI is more than 3(R2=0.515). During the three reproductive periods, R2 of LAIM and LAIHJ is 0.732, 0.761 and 0.661. Conclusions were drawn: the inversion method of LAI at different stages is optimal. HJVI shows obvious advantage for LAI inversion ability. The production of MODIS LAI could be used for crop monitoring in special situation. The study not only broadens the mode of inversion LAI using vegetation index, but also confirms the importance of HJ data in agricultural field.

Abstract:Accurately acquiring crops distribution information is of great significance for agricultural production management and yield estimation, but the roads, forest belts and ditches in the farmland seriously affect the accuracy of crops classification and extraction. Chinese small satellite constellation of small satellites for environment and disaster monitoring and forecasting (HJ-1A/1B satellite) is a good data source for crops classification, because it is free for researchers and has a higher spatial resolution of 30m and a higher time resolution of two days. In this paper, Shuanghe farm in Heilongjiang province of China was the research area, 23 timeseries HJ-1A/1B images which cover the growth period of the major crops from April 3th to November 9th, 2012, were used to monitor the roads and forest belts in the farm, extract spatial distribution of the major crops based on decision tree and objectoriented method, and the classification result was compared to traditional decision tree. The timeseries image set and the timeseries characteristic index set such as NDVI, DVI, RVI, EVI and NDWI were built after the original image data pretreatment. Firstly, the road in the farm was extracted with objectoriented classification based on elements of lengthwidth ratio and other parameters, then the timeseries set was masked by the road in order to rule out the interference of roads, forest belts and ditches for the extraction of crops information. Secondly, seven effective characteristic parameters and 14 sensitive time phases were chosen by using the object spectrum, time phase and time series characteristics. The thresholds of characteristic parameters were determined, and the decision tree classification model of major crops was established. Finally, the major crops in Shuanghe farm such as corn and rice were extracted. The result showed that using many characteristic indices to classify crops was very effective, and especially NDWI was very helpful for rice extraction. The method of decision tree and objectoriented classification was better than the traditional decision tree for extracting the spatial distribution of major crops in Shuanghe farm, it could effectively eliminate the interference of roads, forest belts and ditches in the farm for crops classification, and the total accuracy was increased from 89.22% to 95.18%. The integration of decision tree and objectoriented classification can provide reference for crops distribution information extraction in other agricultural areas with low cost and high precision.

Abstract:With the rapid development of agricultural informationization, the demand for accuracy and reality of regional soil and water resources information data becomes higher and higher. The progress of remote sensing technology makes the selectable data source richer. High spatial resolution images contain rich shape and texture information which are widely used in soil and water resources survey, while traditional image classification method cannot satisfy the requirement any more.Because of this, unmanned aerial vehicle (UAV) images were used as experimental objects, and the image objectoriented classification method based on optimal segmentation scale and decision tree was proposed. Firstly, a segmentation quality function was established based on internal homogeneity and heterogeneity of images, and the optimal segmentation scale was obtained according to this function. Then, optimal segmentation scale evaluation model based on spectral and area information was proposed to evaluate segmentation result. Lastly, soil and water resource information classification was completed by introducing decision tree rule mechanism, and compared with the maximum likelihood classification results. The experimental results showed that the segmentation quality function can obtain optimal segmentation scale accurately, and avoid the subjectivity of manual segmentation. The overall accuracy is 86.78% and compared with 77.59% of maximum likelihood classification method has a great improvement in classification accuracy.

Abstract:Drought is one of the most important agricultural disasters in the Guanzhong Plain, China. Assessing the influence of the droughts in the plain accurately can provide reference for drought mitigation and maintaining stable crop yields. Based on remotely sensed vegetation temperature condition index (VTCI) which was calculated at tenday intervals for monitoring droughts in the years of 2008—2013 in the plain, the Copula function method was used to assess the effect of drought at the main growth stages of winter wheat on the yields. The mutually independent principal factors were extracted from the VTCIs at the main growth stages of winter wheat by using principal component analysis (PCA), overcoming difficulty of parameter estimation for multivariate Copula, and then incorporated into the Copula function to establish a PCA-Copula method. The comprehensive values of VTCIs at the main growth stages were determined by the PCA-Copula method, and then linear regression model between the comprehensive VTCIs and wheat yields was established to assess the effect of drought on the yields. The results showed that the linear correlation coefficient between the wheat yields and comprehensive VTCIs was at the extremely significant level (P<0.001). Compared with the linear regression model based on the entropy value method, the determination coefficient of the model with the PCA-Copula method reached 0.49 from 0.39, which indicated that the fitting degree of the model was improved, and the root mean square error and average relative error between the estimated and measured yields reduced by 30.2kg/hm2 and 0.66%, respectively. These results indicated that the PCA-Copula method was a better approach for accessing the impact of droughts at the main growth stages of winter wheat on the yield.

Abstract:The number of tillers has a significant effect on the winter wheat field management and the prediction of winter wheat yield. However，the traditional manual counting method of the tiller counting is inefficient. With the development of spectral technology and the application of low altitude remote sensing technology in agriculture, a method was provided for monitoring the number of tillers and growth of the winter wheat by calculating crop canopy reflectance and vegetation index. A 4waveband crop monitor with spectral reflectance was used to carry on the experiment (Tainong 18). The instrument can obtain the crop canopy reflecting signals at 550nm, 650nm, 766nm and 850nm simultaneously. After that the crop canopy reflectance was first calculated and then nine vegetation indexes: OSAVI, MSAVI, SAVI, EVI2, TVI, NDGI,NDVI, RVI and DVI, were also calculated. The relationship between the tillering of winter wheat and each index of nine vegetation indexes was analyzed in both regreening and erecting stages. In regreening stage, the correlation between OSAVI（650,850）and tillers was the highest (R2 is 0.85, RMSE is 11893), while in erecting stage, the correlation between EVI2（650,850）and tillers was the highest (R2 is 0.84, RMSE is 73.04). The results of the test showed that there was a significant relationship between the winter wheat tillers and the two vegetation indexes. This may help the development of the instrument for winter wheat tillers counting based on canopy spectral reflection. The conclusions can be used in rapid predicting of wheat tillering and giving suggestions to field precision management.

Abstract:Among the phase change material microencapsulation process，In Situ Polymerization，Interfacial Polymerization, and other polymerization method are more commonly used in small scale laboratory chemical preparation. In the process of In Situ Polymerization, wall materials of monomer or prepolymer and the catalyst need soluble in the continuous phase, while Interfacial Polymerization reaction requires two kinds of wall material monomers dissolving in immiscible dispersed phase and a continuous phase respectively. Characteristics of microencapsulated phase change material include its apparent morphology, thermal properties of the core material, particle size distribution, toughness and thickness of wall materials and other factors. Selection of core materials in microencapsulation mainly considers their phase transition temperature and ambient temperature of applications, and the screening of wall materials mainly observed their balling effect, chemical stability, thermal stability and mechanical strength, etc. Latent functionally thermal fluid means when microencapsulated phase change material powder is added in a singlephase heat transfer fluid, a stable suspension of solidliquid twophase fluid is made, namely phasechange microcapsule suspension. In order to develop a proper kind of microencapsulated phase change material (MEPCM) which can be applied in greenhouse heat storage, three different kinds of MEPCMs were prepared, with butyl stearate, No. 30 paraffin and their mixture as the core materials respectively, melamine resin and polyurea resin and polymethyl methacrylate (PMMA) as wall materials respectively. The property characterization analysis demonstrated that melamine resin microcapsule performed the best: the particle sac wall was smooth and tight; the particle size distribution was uniform and concentrated at about 1μm, and the average diameter of microcapsule granules was 75.15μm; the heat resistant temperature was higher than 100℃, meeting the demands of solar greenhouse application; the thermal gravimetric surplus rate of the microcapsules was more than 50%, far larger than that of the other two kinds of polyurea resin and polymethyl methacrylate microcapsules, namely with relatively higher thermostability. Therefore, the melamine resin can be used as suitable wall material of microcapsules for preparing microencapsulated phase change material suspensions which can be utilized as liquid medium for solar heat collection, conveyance and release in greenhouses.

Abstract:To study the cavitation occurring in diesel nozzle and its effects on the flow capacity, the process of cavitation and the flow characteristics in diesel injector orifice were analyzed based on optical testing and threedimensional CFD simulation. In the experiment, the visualization of cavitation was recorded by a highspeed camera, the frame rate was set to 6688 frames per second. The highfrequency Kistler pressure transducers were assembled before and after the nozzle to acquire pressure. Ultimately, the data of pictures and pressure were stored by a computer. The 3D CFD diesel cavitation simulations were carried out under conditions of different inlet pressures and back pressures based on the commercial code Fluent. The CFD simulations were validated by the experimental data. The results showed that: when K>2.49, there were no bubbles in the nozzle, which was named nocavitation period; during nocavitation period, both the gasliquid mixed phase volume fraction and the fuel mass flow in each section did not increase and the flow coefficient was constant. When K≤2.49, it is the cavitation developing period when the gasliquid mixed phase volume fraction of the entrance of the nozzle (plane A) started to increase which represented cavitation inception. At the same time, the growth rate of fuel mass flow reduced, and the flow coefficient began to decreased. When K≤1.91, the gasliquid mixed phase volume at plane A became stable, which meant the cavitation saturation period. During the saturation period, the fuel mass flow rised to its maximum and maintained stable while the flow coefficient decreased. It can be seen that the cavitation occurred in diesel injector nozzle had large impact on the flow characteristics. Meanwhile, the cavitation had impact on the fuel mass flow, the flow coefficient and the gasliquid mixing phase volume fraction at different nozzle cross sections.

Abstract:The active steering system can provide steering intervention to improve the vehicle handling stability. In order to improve the vehicle stability, a rear wheel active pulsed steering system was proposed and its performance was analyzed and verified by simulation and vehicle test. Firstly, a hydraulic pulsed steering system was designed and modeled. A simplified 2DOF vehicle model was considered as the analytical model, and a rear suspension ADAMS model with the hydraulic pulse actuator was developed. Secondly, the effect of the steering system on vehicle stability was studied and the pulse signal parameters (frequency and amplitude) were evaluated to determine their optimum values. And then, a control structure and algorithm were designed, and the simulations were addressed based on CarSim and Simulink to verify the performance of the proposed system. Finally, a set of hydraulic pulse steering device was designed and assembled to carry out road experiments to assess the applicability of the proposed system. Results from simulation and test indicated considerable improvements in vehicle yaw stability can be achieved and also the roll angle was reduced for improving the vehicle rollover ability. Sideslip angle and lateral acceleration in the peak were reduced by 46.8% and 23.5%, which improved the vehicle lateral stability. Roll factor can be controlled in the set threshold limits \[-08,08\] and vehicle roll angle was decreased by 25.4%, the vehicle anti rollover ability was improved and showed a better control effect than the active steering system. The considerable improvements in vehicle stability can be achieved.

Abstract:The permanent magnet slip clutchelectronically controlled hydraulic power steering system which is referred as P-ECHPS was proposed. The speed control model of permanent magnet slip clutch (PMSC) which is the key transmission part of P-ECHPS was established and all subsystems of P-ECHPS including of mechanical systems, hydraulic systems and three degrees of freedom steering dynamics system were also established in Matlab/Simulink. The variable assist characteristic curves were designed by analyzing the requirements of steering system under different speeds. According to the variable assist characteristic curves and the model of steering pump, the ideal speed of steering pump was obtained. For P-ECHPS containing various uncertain factors during steering process, such as parameter perturbation and external disturbance, and requirement of fast response, the adaptive nonsingular fast terminal sliding mode was used to control the speed of PMSC. Further it can realize the indirect control of P-ECHPS. The controller was designed according to the adaptive nonsingular fast terminal sliding mode control strategy. Through simulation, the results show that adaptive nonsingular fast terminal sliding mode control can ensure the output speed of PMSC track to the ideal speed quickly and has great robustness. The convergence rate of adaptive nonsingular fast terminal sliding mode control respectively increased by about 82.9% and 66.7% than that of sliding mode control and nonsingular terminal sliding mode control. It can also realize variable assist characteristic accurately to meet the handling stability and energy efficiency.

Abstract:There are 32 ways in which the two RR constraints are added to the 6R loop to form 1DOF eightbar linkage. First, the solution curve was obtained based on expanding burmester curve theory. Then the eightbar linkage can be synthesized by adding two RR constraints on the solution curves. Each point on the solution curve can be viewed as the added RR constraint, so infinitely many solutions can be got. The solution curve can be converted into the solution plane which presents infinitely many solutions. The solution plane was called solution region. The solution region was divided into two categories according to whether the two added RR constraints were related. The linkages were classified by the method of Assur group. The motion of eightbar linkage was analyzed by the iterative position analysis method which relegated the fourbar Assur groups or sixbar Assur groups to several twobar Assur groups. Whether a linkage could be defected depends on if it can sequently move through the four positions of 6R loop. After the defect linkages were removed, the feasible solution region can be got. In the solution region, the feasible linkage can be classified into two types, the crank and the noncrank, according to the rotatable angle range of the driving link. The solution region synthesis theory makes designers choose the feasible linkage directly and accurately, so the design efficiency was improved. In addition, eightbar linkage can achieve more movement function compared with sixbar linkage and fourbar linkage. The synthesis of eightbar linkage for 6R loop through four positions makes the solution region synthesis theory more perfectly, provides more choices for designer and lays the foundation for the application of eightbar linkage in practice. Finally, an example of eightbar linkage specifies the four positions synthesis.

Abstract:Magnetorheological (MR) valve is a kind of smart control mechanism that using magnetorheologcial fluid as the working fluid. A compact hybrid fluid flow MR valve was developed and prototyped, the fluid flow paths of the proposed MR valve were consisted of a single annular flow channel, a single radial flow channel and an orifice flow channel through structural design. In order to investigate the changes of the magnetic flux density and yield stress along the fluid flow paths under the four different radial resistance gaps, the magnetic circuit design and finite element analysis were carried out. The simulation results showed that this design methodology can provide a larger pressure drop of 3342kPa at 0.5mm radial resistance gap and 1.0mm annular resistance gap, which constrained in a volume space of MR valve with an outer diameter of 62mm and overall length of 80mm. Meanwhile, the experimental pressure drop under the four different radial resistance gaps was also carried out on the test rig. The results showed that the pressure drop was increased as the applied current increased, and the pressure drop also increased as the radial resistance gap decreased from 1.5mm to 0.5mm, the maximum pressure drop was approximately 2650kPa at the applied current of 1.2A when the radial resistance gap was 0.5mm, which was well accorded with the simulation results. This proposed MR valve significantly improved its efficiency through compact design and changeable radial resistance gap, which is beneficial to control the MR damper as a bypass control valve for its good pressure regulating capability.

Abstract:In order to make error compensation of machine tools relate to error modeling closely, and to avoid the tedious calculation of Jacobian matrix, a geometric error compensation method of machine tools based on differential change construction was proposed. At first, geometric error modeling of machine tools was developed using differential change matrices of coordinate frames. According to the forward kinematic chain of the machine tool, differential change matrix of each axis was established. The differential motion vector of each axis was obtained according to the properties of geometric errors. On the basis, the impacts of geometric errors of each axis on the precision of the tool were calculated. The integrated differential motion vector in the coordinate frame of tool was obtained by adding these impacts together. Then, based on homogeneous motion matrix of forward kinematics chain of the machine tool, the integrated geometric error model of the machine tool was established by transforming the integrated differential motion vector to coordinate frame of the working table. Next, the differential change construction was used to extract the corresponding column vector of differential change matrix of each axis to establish Jacobian matrix of the machine tool. The Jacobian matrix can compensate the integrated differential motion vector in the coordinated frame of tool. The differential change construction does not need extra calculation, and reuses the differential change matrices established in modeling. At last, the workpiece cutting experiments were carried out on Carver800T threeaxis machine tool. The results show that the geometric error compensation based on differential change construction is effective.

Abstract:In order to solve problems that conventional electromechanical converter of 2D valve had deficiency of complicated magnetic circuit, intricate structure and lacking high pressure resistance, a torque motor with simple structure, limited working stroke and high pressure resistance was developed based on symmetrical magnetic circuit with singlephase excitation. Working principle and detailed structure were discussed. Prototype motor was fabricated and test rig for static and dynamic characteristics was built. Torqueangle characteristics and frequency response were studied using approaches of magnetic circuit analysis, FEM simulation and experiments. The experimental results were in a close agreement with the simulated results, which indicated the torqueangle characteristic was close to linear relationship and its amplitude increased with excited current. The simulated results don’t have hysteresis characteristics since it is a static electromagnetic simulation. And experimental curves show slight hysteresis, which are mainly due to magnetic hysteresis loops of soft magnetic materials and each static and dynamic frictions existing in the test rig. The maximum static torque reaches about 0.042N·m and the experimental frequency width can meet requirements of 2D proportional and directional valves. Therefore the proposed torque motor is appropriate to be an electromechanical converter of such applications. If proper heat treatment can be performed, the static and dynamic characteristics of torque motor will be further improved.