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The suspension characteristics of the threshed materials of foxtail millet are the basic characteristics for the research of cleaning working parameter optimization and improved design for the cleaning equipment, and the foxtail millet was harvested by the whole-feeding combine harvester. The threshed materials to be cleaned of foxtail millet include the grains, spikelets, stalks and leaves. Based on the requirements of the Chinese national standard test methods for forage seed suspension velocity, using the suspension velocity testing device for agricultural materials, we designed and conducted the staged suspension experiments to measure the suspension velocities of the 4 kinds of threshed materials of foxtail millet respectively, and we also measured the suspension velocities of the threshed materials with different moisture contents, and then we researched the relations between the suspension velocity of each part of threshed materials and its moisture content. Based on the differences among the measured suspension velocities of threshed materials, we estimated the suitable range of cleaning air velocity and conducted the cleaning experiment via cleaning experimental device to verify our estimation. We got the threshed materials with different moisture contents by means of rehydrating and drying. We immersed the threshed materials harvested into the water for 6 h to make their moisture contents saturate, and then we put the saturate threshed materials into the thermostatic drier box to dry for different times at 100 ℃. The drying times were 10, 20, 30 and 40 min respectively, and thus we got other 4 kinds of threshed materials with different moisture contents from the harvested threshed materials’, and so we totally measured 5 kinds of threshed materials with different moisture contents. The staged suspension experiments included 3 stages. When there were one third of the materials to be measured suspending in the tapered observed pipe at some height, one suspending stage was reached. We measured the suspension velocity of the suspended materials via DP2000-11 type intelligent pressure air-volume anemometer in every stage, and there were 6 measure points in every stage, and we calculated the average value of the 6 measured values. We used the suspended height ruler to measure the suspension height range of the suspended materials, and we used the average value and the suspension height range to calculate the suspension velocity range of the suspended materials based on the flow consistency principle. Synthesizing the 3 suspension velocity ranges, we got one suspension velocity range of this kind of material with a certain moisture content. There were 6 repeats of suspension velocity measurement for every kind of material with a certain moisture content. Synthesizing the 6 suspension velocity ranges of a kind of material with a certain moisture content, we finally got the suspension velocity ranges of this kind of material. The experimental results showed that the suspension velocities of grains, spikelets, stalks and leaves of threshed materials of foxtail millet harvested by combine harvester were respectively 4.29-8.88, 1.03-5.48, 1.71-5.33 and 1.03-3.09 m/s. There was no overlapping numerical interval between the grains’ suspension velocity range and the leaves’, while there were some overlapping numerical intervals between the grains’ suspension velocity range and the spikelets’ or the stalks’. With the decrease of moisture content of foxtail millet, the overlapping numerical intervals were all reducing between the grains’ suspension velocity range and the spikelets’ or the stalks’ or the leaves’. We used the maximum of the suspension velocity range of every kind of material with a certain moisture content to carry out a statistical analysis. The moisture content affected the suspension velocity of every component of the threshed materials significantly, and the significance level P values were all less than or equal to 0.048 8. With the decrease of moisture content, the suspension velocities of grains, spikelets, stalks and leaves were all decreasing, and there were quadratic function relations between the moisture content and the grains’ suspension velocity or the spikelets’ or the stalks’ or the leaves’, and the fitting precisions were all greater than or equal to 0.951 2. The results of cleaning experiment proved that the estimation was rational. The suitable range of cleaning air velocity for the threshed materials of foxtail millet was 4.29-5.48 m/s, and the optimal air velocity at air outlet was 4.47 m/s. Under the action of airflow with optimal air velocity, the loss ratio of grain was 4.68%, and the cleanliness of grain was 98.83%. The research results can provide reference for the determination of the timely harvest time and the optimal cleaning working parameters. [ABSTRACT FROM AUTHOR]

Suspension velocity of agricultural material is important basic data for the research of technology and equipment for mechanical cleaning. Given the characteristics of threshed materials to be cleaned of crops harvested by combine harvester, based on the suspension principle of material and the characteristics of mechanical cleaning working condition, we designed a kind of vertical air sweeping suspension velocity testing device for agricultural material. This device mainly consists of 3 kinds of components, including the air force and its controlling components, the flow field structural components and the measuring components. The air force and its controlling components are directly connected with the flow field structural components by flanges in vertical direction, and the measuring components are installed on the flow field structural components. The structure is compact. The air force and its controlling components consist of the centrifugal fan, the frequency converter, the conduit coupler between fan and pipelines, and the protecting net. The flow field structural components consist of the grille tube, the airflow-smoothing grille, flanges, holding net for materials, entrance gate of materials, collecting board for materials, lower airflow-stablizing pipe, tapered observation pipe, upper airflow-stablizing pipe, obstructive net for materials, and so on. The measuring components consist of the L type Pitot tube, bracket of Pitot tube, intelligent pressure air-volume anemometer, air conduit, suspended height ruler, observation platform, and so on. The overall size of this device (length × width × height) is 1.8 m × 1.1 m × 4.2 m. The motor power of fan is 7.5 kW. The airflow velocity can reach 40 m/s in this device. The flow field structural components are mainly formed by the grille tube, lower airflow-stablizing pipe, tapered observation pipe and upper airflow-stablizing pipe connected successively via flange connections in vertical direction. The 4 pipes are all welded with flanges at both ends and made of polymethyl methacrylate. The lengths of the 3 pipes except the grille tube are all 1 m. The inner diameters of the grille tube, lower airflow-stablizing pipe and the small end of the tapered observation pipe are all 240 mm. The dip angle of tapered observation pipe is 4° and its inner diameter of big end is 380 mm. We designed a circular airflow-smoothing grille installed in this device to avoid generating eddy at the outlet of fan, and its height is 100 mm, the side length of its square hole is 30 mm, and the thickness of grille plate is 2 mm. The anemometer can display the temperature, humidity, pressure, airflow velocity and flow rate in real time in the measurement. We designed and conducted staged suspension experiments to measure the suspension velocity of each component of the threshed materials to be cleaned by combine harvester during the harvesting time of foxtail millet, buckwheat and oat, respectively. The results show that the range of suspension velocity of grains, spikelets, stalks and leaves of threshed materials to be cleaned of foxtail millet is respectively 4.29-8.88, 1.03-6.48, 1.71-6.09 and 1.03-3.09 m/s. The range of suspension velocity of grains, ramulus, stalks and leaves of threshed materials to be cleaned of buckwheat is respectively 4.47-10.18, 1.85-5.18, 2.80-8.37 and 0.76-2.99 m/s. The range of suspension velocity of grains, testas, ramulus, stalks, leaves and unpeeled grains of threshed materials to be cleaned of oat is respectively 4.35-11.01, 0.62-1.71, 1.62-4.52, 1.14-6.28, 0.91-3.56 and 3.24-9.48 m/s. The grains’ suspension velocities of foxtail millet and oat are both different from their most light impurities’, the grains’ suspension velocity of oat is similar to its unpeeled grains’, and the grains’ suspension velocity of buckwheat is different from its minor light impurities’. This study can provide reference for the research and development of cleaning technology and equipment for agricultural materials. [ABSTRACT FROM AUTHOR]

Foxtail millet is a kind of minor coarse cereal. It is not one of the main grain crops, and is a kind of rainfed crop. So, it is mainly planted in the hilly and mountainous areas in northern China. Foxtail millet is becoming more and more popular in congee because of its mellow taste and abundant nutritional value. Given the characteristics of small and scattered planting plots for foxtail millet in northern hilly and mountainous areas, small seeder is more suitable for this kind of plot. According to the agronomic requirements of fine and small-amount sowing for foxtail millet, we design and manufacture the 2BZ-2 type fine and small-amount seeder for foxtail millet. This seeder consists of 2 sowing units, transmission system, ground wheels and body frame. Every unit is mainly made up of seed-metering device, furrow opener, soil coverer and press wheel. We use the tilt dise-type fine and small-amount seed-metering device for foxtail millet that was designed previously, and its working angle is 45°, and it has 36 filling holes and 36 seeding grooves. This device has got the national invention patent in China, and we have published an academic paper about it on Transactions of the Chinese Society of Agricultural Engineering. We design a kind of ship-shaped shovel type furrow opener, and its penetrating angle is 60°, its soil-cutting angle is 30°, its trenching width is 30 mm, and its height is 100 mm. We design a kind of scraper type soil coverer, and it mainly consists of 2 covering boards, connecting board and pull rod. The covering board is trapezoid-shaped, and its length is 100 mm, its front width is 80 mm, its back width is 40 mm, and its thickness is 3 mm. The included angle between the 2 covering boards is 50°, the inclined angle of the covering board toward the ground is 70°, and the width of the back opening between the 2 covering boards is 30 mm. We push the seeder and provide the driving force. The ground wheels pass the driving force to the seed-metering device via the transmission system. The transmission system is composed of two-stage chain drive and one-stage bevel gear drive. The chain drive uses the 08B roller chains and the matched chain wheels to drive down. The bevel gear drive uses 45° straight bevel gears to realize constant speed drive. According to the experimental requirements of Chinese National Standards, we design and conduct the seeding performance experiments and the field sowing experiments to test the working performance of this seeder. The seeding performance experiments include the tests of the consistency of every row's seeding quantity, the steadiness of total seeding quantity and the percentage of damaged millet. The field sowing experiments include the tests of the uniformity of sowing quantity and the consistency of sowing depth. The results of the seeding performance experiments indicate that, the coefficient of variation of consistency of every row's seeding quantity is less than or equal to 1.10%, the coefficient of variation of steadiness of total seeding quantity is less than or equal to 0.66%, and the percentage of damaged millet is less than or equal to 0.05%. The results of the field sowing experiments indicate that, the qualified index of hill spacing is greater than 83%, the replay index is less than 7%, the miss-seeding index is less than 12%, the coefficient of variation of qualified hill spacing is less than 10%, and the coefficient of variation of sowing depth is less than 1.5%. All the 8 indices meet the requirements of Chinese machinery industry standards. This study can provide a theoretical reference for the design and analysis of the fine and small-amount seeding equipment for foxtail millet suitable for the hilly and mountainous areas. [ABSTRACT FROM AUTHOR]

In order to solve the difficulties of sowing for foxtail millet and improve the low germination rate of millet after sowing in dry land of North China, we firstly studied the agricultural requirements of precision drill of millet without thinning out seedlings. We prepared a mixed suspension of foxtail millet using water and agricultural super absorbent polymers, because the agricultural super absorbent polymers can promote crop growth. We did some experiments to find suitable super absorbent polymers and the optimal proportion for mixed suspension according to the requirement of fluid seeding. At the same time we designed a kind of seed metering device by small-amount liquid for foxtail millet. This paper determined the number of rollers, dimension parameter and combination form of tube. It also expounded sucking seeds, delivering seeds and metering seeds of this seed metering device. This device consists of seed box, delivery pump, pump tube, three-way tube, long bent tube, end drainage tube and short bent tube. The function of delivery pump is providing power for the seed metering device, the function of three-way tube is dividing and combining the mixed suspension, the long bent tube or the short bent tube can improve the uniformity of seeding, and the end drainage tube can decrease every drop volume of mixed suspension to ensure that every drop has 2-3 seeds. Because the delivery pump has impulsive motion, we greatly reduced the impulsive motion of this device by using 6 rollers of .delivery pump and designing the structural style of tube, which has long bent tube, short bent tube, three-way tube and end drainage tube. The length of long bent tube is 100 mm, and the length of short bent tube is 74.4 mm. We also chose the material and diameter of tube. The material of tube is silica gel, which has the advantages of good elasticity and long service life. The diameter of pump tube, long bent tube, short bent tube and end drainage tube is 4.8, 4, 4 and 4 mm, respectively. Finally we designed and conducted the experiments of the uniformity and steadiness for mixed suspension of millet, and the variability coefficient of seed number was adopted. And we performed the performance tests with 4 indices adopted, including the percentage of damaged seeds, qualified rate of hill distance, qualified rate of seed number per hill, and rate of no seed hill for seed metering device in laboratory. We also carried out the field experiment of sowing with 3 indices including the qualified rate of hill distance, qualified rate of plant number per hill and seedling emergence rate for this device. The results showed that the suitable agricultural super absorbent polymer was Anxin for preparing the mixed suspension of foxtail millet, and the quality ratio of super absorbent polymers, grain of millet seed and water was 1.1 : 10 : 200 in mixed suspension; the variability coefficient of seed number was 9.8% in this mixed suspension, and was 9.7%-10.4% within 5 hours, and the seeds in mixed suspension had no obvious settlement. The percentage of damaged seeds was less than 0.01%, the qualified rate of hill distance was greater than 86%, the qualified rate of seed number per hill was greater than 75%, and the rate of no seed hill was less than 4% in laboratory test. The qualified rate of hill distance was greater than 77%, the qualified rate of plant number per hill was greater than 74%, and the seedling emergence rate was greater than 87% in field experiment of sowing. The results provide a theoretical reference for the design and analysis of seed metering device by small-amount liquid for small grain seeds. [ABSTRACT FROM AUTHOR]

In order to explore crack damage of apple peel in the process of naturally growing and evaluate quality of different peels varieties, peel samples coming the shadow side and sunlit side of three apple cultivars，Danxia, Fuji, Star-krimson were chosen for longitudinal tests of tensile stress relaxation and creep by means of electronic universal testing machine. Stress-time curve of relaxation test and strain-time curve of creep test were obtained from the tests; and initial stress, residual stress and strain holding of peel relaxation and initial strain, stress holding and creep value of peel creep were also gained. We then set up relaxation five component Maxwell model and creep Burgers model by use of experimental data; and established relaxation and creep characteristic parameters for correlation analysis; and used the relaxation and creep model parameters for principle component analysis. The results indicated that under the action of the same load, discrete degree of peel initial stress was far lower than that of peel residual stress. The standard deviation of initial stress was within 0.4 percent of the average, but the residual stress standard deviation reached about 10% of its average. Initial stress, residual stress, strain holding, initial strain, and stress holding of Star-krimson peel had significant differences (p <0.01) from Danxia and Fuji peels. For different varieties, peel relaxation initial stress, relaxation residual stress; and creep initial strain were large, but creep value was small. For relaxation model parameters of peel, the equilibrium modulus of Star-krimson peel was much larger (p < 0.01) than that of Danxia and Fuji peel; but its relaxation time were much less (p < 0.05) than that of Danxia and Fuji peel. Viscosity factors of Star-krimson peel showed a significant difference (p < 0.05) from that of Fuji peel. For creep model parameters of peel, the mean value of instant elastic modulus of Star-krimson peel was the greatest and that of Fuji peel was the lowest; but decay time and viscosity factors of Fuji peel were the largest. There was a significant (p < 0.05) difference between instant elastic modulus, decay time, viscosity factors of Star-krimson peel and that of Fuji peel. It was found that the relaxation and creep test can objectively describe internal tissue structure differences around different peels; and organization structure of Star-krimson peel had better fluidity and stronger elasticity and that of Fuji peel had weaker fluidity and stronger viscidity. When the principle component analysis was performed for relaxation and creep model parameters of peel, eigenvalue was more than 1 for selected principle component and accumulative contribution rate of Danxia, Fuji, and Star-krimson peel reached 85.13%、83.94% and 91.68%, respectively. Contribution rate of elasticity factor which was on behalf of peel quality was relatively larger in Star-krimson peel, but contribution rate of viscidity factor was relatively higher in Fuji peel, this reflected that Fuji peel surface was easier fragmentation than Star-krimson peel surface；and Fuji peel surface was also easy to injury including harvest, packaging, transportation and storage. The results have significances to provide better apple cultivation and perfect apple texture evaluation system. [ABSTRACT FROM AUTHOR]

In order to solve the difficulties of sowing for small grain seeds, such as foxtail millet, we firstly study the agricultural requirements of precision drill of millet without thinning out seedlings. After analyzing the advantages and disadvantages of different seeding devices, we design a kind of tilt dise-type fine and small-amount seed-metering device for foxtail millet. We measure the shape and dimension of the millets with the microscope using the projection method, and the friction coefficient of millet with different materials as requested by the national standard of China. We analyze the motor process of millet, which helps us design the structure of this device. It is mainly made up of filling dise, shell, discharging dise, elastic flipping device and drill shaft. It has many advantages. Its structure is simple, and its working principle is reliable. Its working position tilt is from 45° to horizontal direction. The overflowing seeds from filling holes are flexibly cleaned under the action of gravity, so they will not be damaged. There are 36 filling holes in the filling dise, and they are uniformly distributed on the circumference of filling dise. Matched with filling holes, there are 36 seeding grooves in the discharging dise, which are uniformly distributed on the circumference of discharging dise. The filling dise is above the shell, and the discharging dise is below the shell, both of which synchronously rotate. There is a passing hole between them in the shell. The millets fall in the filling holes, and revolved around the drill shaft together with filling holes. When they arrive at the passing hole, the millets leave the filling holes, then pass through the passing hole and enter the seeding grooves. The millets continue to revolve around the shaft together with the grooves. There is a dropping hole at the bottom of the shell. Before they arrive at it, the millets move to the end of the grooves. When they arrive at the dropping hole, the millets leave the groove, pass through the dropping hole, and fall into the seeding tube. According to the movement characteristics of millets, on the premise of not damaging them, we design the shapes and dimensions of the filling hole, seeding groove, passing hole and dropping hole. This device is expected to seed 2-3 millets from every seeding groove, and the intervals of millets are kept steady on the soil. We especially design an elastic flipping device to flip the millet stuck in the filling hole out of it, which is installed on the upper boss above the passing hole of the shell. We design the fit clearance of 0.2 mm between filling dise, discharging dise and shell simultaneously, thus eliminating the friction between them. In order to test the performance of this device, we use 6 indices from the national standards of China. They include the percentage of damaged seeds, variability coefficient of steadiness of total seeding quantity, qualified index of hill spacing, repeated sowing index, miss-seeding index and variability coefficient of qualified hill spacing. We design and conduct the experiments of the steadiness of total seeding quantity and the uniformity of seeding rate with this device. We also measure the percentage of damaged seeds discharged from this device. The results show that the variability coefficient of steadiness of total seeding quantity is less than 0.7%, the qualified index of hill spacing is greater than 86%, the repeated sowing index is less than 12%, the miss-seeding index is less than 7%, the variability coefficient of qualified hill spacing is less than 5%, and the percentage of damaged millet is less than 0.05%. All the indices meet the requirements of the industrial standards of China. It will provide a theoretical reference for the design and analysis of fine and small-amount seed-metering device for small grain seeds. [ABSTRACT FROM AUTHOR]

In the pig breeding environment, pig adhesion and debris shielding made it difficult to detect multiple targets of pig individuals. In this paper, pigs in the pen were used as the research object, and the video frame was used as the data source to propose a model FPA-Tiny-YOLO that combines Feature Pyramid Attention (FPA) and Tiny-YOLO. In this model, attention information was integrated into feature extraction, semantic content of different regions was aggregated hierarchically, and global context information was mined. Image processing (include randomly change the brightness, adding Gaussian noise and flipping 180°) was performed on video clips of 45 pigs in 8 bars with age of 20 to 105 days, and 4 102 labeled pictures were obtained. Four kinds of deep FPA modules were constructed and added to YOLOV3 and Tiny-YOLO models. Experiments show that adding a variety of feature pyramid attention information could improve the accuracy of Tiny-YOLO and YOLOV3 models to some extent. Compared with the YOLOV3 models, before adding the FPA module, the Tiny-YOLO model had higher detection accuracy, and the detection real-time performance was better than that of the YOLOV3 model with the same module added. After adding the FPA module, the detection performance of the Tiny-YOLO model was better than that of the YOLOV3 models, the mAP, Precision ratio, Recall rate and F1 value of the Tiny-YOLO model with the FPA-3 module increased by 8.4, 1.04, 7.93, and 5.09 percentage points compared to the YOLOV3 model with the same FPA module. The Recall rate, F1 value and mAP of Tiny-YOLO model with FPA-3 module for multi-target detection of group pigs on the test set reached 86.09%, 91.47% and 85.85% respectively, which improved by 3.75, 2.59 and 4.11 percentage points respectively compared with Tiny-YOLO model without FPA module, The the Recall rate, F1 value and mAP decrease as the score threshold increases when the score and IOU value fixed, but the Precision ratio gradually decreases, whicb indicating that the depth of the FPA module had no regular effects on the detecting effect. The test set pictures were divided into four scenes according to whether adhesion or shielding to explore the robustness of the Tiny-YOLO series models. The experiments showed that compared with Tiny-YOLO model, the Recall rate, F1 value and mAP of the Tiny-YOLO model adding FPA-3 module were improved by 6.73, 4.34 and 7.33 percentage points respectively, the Tiny-YOLO model adding FPA module could extract more complete edges of pigs and had higher prediction reliability and had better detection effects for the pigs far away from the camera and with occlusion, the feature pyramid attention information was beneficial to precisely and effectively conduct multi-target detection of live pigs in different scenes. The research results can provide a reference for the subsequent mobile application of pig identification and behavior analysis. [ABSTRACT FROM AUTHOR]

Millet is one of the most important special crops in arid and semi-arid north region of China. It has the features of strong tolerance to drought and barren soil, high nutritional value, and wide adaptability, and therefore becomes an important part of industry structure development for specialty crop in China. As people adjust their diet structure, millet has increasingly become an essential and high quality food on the dining table. However, the limited development in mechanization of millet production equipment has significantly restricted the development of millet industry. Millet can be mechanically damaged due to the friction in the processes of seeding, harvesting, milling, storage and transportation. So it is important to understand the friction characteristics of millet and use the friction parameters for the design of equipment during the above processes and applications of related technologies. The previous research on grains’ friction characteristics was mostly about big grain kernel and small grain kernel like millet has been rarely studied. In this research, a typical millet, Jingu-21, produced in Shanxi Province, was selected as test material with 4 moisture content treatments of 10.7%, 13.7%, 16.0% and 19.8%.. The parameters of friction characteristics of millet including repose angle, coefficient of sliding friction and coefficient of internal friction were measured using a test device of repose angle, a test device of sliding friction and a direct shear apparatus. Variations of the friction characteristics affected by moisture content, contact material and shear velocity were quantified and modeled. The results showed that the moisture content ranging from 10.7% to 19.8% did not significantly affect the size and shape of millet grains, which in turn were not significant factors influencing the friction characteristics of millet. The friction between millet and contacting surfaces was mainly caused by the meshing of concave and convex surfaces and the adsorption of millets. Moisture content had a significant effect on repose angle of millet, which increased from 27.32° to 28.43°. The coefficient of sliding friction linearly increased as the moisture content increased, and the coefficients of static/dynamic sliding friction between millet and steel, iron and acrylic were 0.185-0.290/0.169-0.278, 0.212-0.336/0.190-0.319 and 0.190-0.312/0.182-0.302, respectively. The coefficient of sliding friction of millet against iron plate was the highest, while that against steel plate was the lowest. In the terms of friction reduction, the mechanical parts contacting with millet, such as metering device, should adopt steel material. The internal friction coefficient of millet was not affected by the shear velocity (P>0.05), but linearly increased as the grain moisture content increased, and decreased significantly as the normal stress increased (P<0.01). The coefficient of internal friction of millet decreased quadratically as the normal stress increased, and tended to be stable when the vertical stress was higher than 150 kPa. When the shear velocity was 4.8 mm/min, the normal stress was 50-200 kPa, and the moisture content was 10.7%-19.8%, the coefficient of internal friction of millet ranged from 0.501 to 0.639. In order to improve the flow characteristics of millet in the processes of seeding, storage and transportation, the moisture content should be reduced and the normal stress be increased appropriately. The above results were analyzed using the statistical regression and the mechanical performance parameters of millet on friction were established as test elements respectively. The study can provide a theoretical basis for the design and development of millet mechanization equipment. [ABSTRACT FROM AUTHOR]

In order to clarify the rheological mechanical properties of millet grain group during mechanical harvesting and processing, this paper studied the effects of different varieties and different moisture contents on the creep characteristics of millet grain group. In this experiment, different varieties (Jingu 21, Zhangza 10), and different moisture contents (12.10%, 16.05%, 20.00%) of millet grain group were selected as creep experimental factors. The creep characteristics (instantaneous elastic modulus, delayed elastic modulus, relaxation time and viscosity coefficient) of millet seed group were used as experimental indicators, and one-way analysis of variance and multi-factor analysis of variance were performed. Based on the original contents of millet seed group, the target moisture contents of the millet grain group were formulated to be 12.10%, 16.05%, 20.00%. The experiment was conducted on the CMT-6104 universal testing machine, and the special fixture for testing the creep characteristics of millet grain group was designed. Combining the Burgers model, nonlinear programming method was used to optimize search regression parameters, and creep parameters of millet grain group were obtained. The creep curve of millet grain group of different varieties showed that, as time going on, the amount of deformation caused by creep tended to be constant, which reaching the strain saturation. There were differences in the millet grain group creep characteristic curves of the different varieties. The significance test standard was 0.05, and the variance analysis was performed. The results showed that the creep characteristics of millet grain group could be described by the four-element Burgers model, and the creep parameters of millet grain group with different moisture content and different varieties were different. The variety had a significant effect on the delayed elastic modulus of the millet grain group. The delayed elastic modulus of the Jingu 21 millet grain group was higher than that of Zhangza 10. The moisture content had significant effects on the instantaneous elastic modulus, delayed elastic modulus and viscosity coefficient of the millet grain group, which was decreasing while the moisture increasing. The instantaneous elastic modulus of the millet grain group with the water content of 12.10% was significantly higher than the water content of 16.05% and 20.00%. The delayed elastic modulus of the millet grain group with the moisture content of 12.10% was significantly higher than the water content of 20.00%. The instantaneous elastic modulus and the delayed elastic modulus represented elasticity and hardness of the millet grain group, respectively. With the increasing of the moisture content of the millet grain group, the instantaneous elastic modulus and the delayed elastic modulus of millet grain group decreased, resulting in a high increasing of the creep curve. The strain in the screw conveyor of combine harvester was correspondingly larger. In this paper, the creep properties of millet grain group with different varieties and different moisture contents were studied experimentally, which provided theoretical support for low-loss harvesting, processing and storage and parameter optimization of millet. There are many factors affecting the mechanical properties of the material, in addition to the influence of moisture contents and varieties, it is also related to many factors such as temperature, internal molecular structure and chemical composition of the material, et al. The rheological properties of agricultural materials need to be further studied in conjunction with the principles of life sciences. [ABSTRACT FROM AUTHOR]

Caragana Korshinskii Kom were charred to yield the biochar in the temperature of 200℃, 300℃, 400℃ and 600℃. The components of Caragana Korshinskii Kom biochar were analyzed, the structure was surveyed through SEM and the adsorption isotherm curve was plotted with the specific surface area analyzer. The pore volume, size, and specific surface area were calculated. Biochar were mixed into soil column to detect the adsorption ability to diuron herbicide. The results showed that the adsorption isotherm curves of Caragana Korshinskii Kom biochar were the traditional I adsorption curves, the productivity of biochar decreased with the raising of charring temperature. Biochar, charred at the temperature of 600℃, had achieved 44.71% of yield rate of carbonization, 187.56 m2·g-1 specific surface area and mean 4.83 nm pore size. The microspore volume account for 53% in total pore volume. 1% of biochar had the significant effect on adsorption of diuron in soil, 3% of biochar in soil reached an optimal application amount balancing between its properties and cost. [ABSTRACT FROM AUTHOR]

Millet contains protein, vitamin B1 and other mineral elements needed for human health, which has functions of enhancing blood circulation, brain tonic, and sleep quality. In recent years, the market demand for millet is rising. However, the mechanization level of millet harvesting is low. Manual harvesting is very common, which requires high labor intensity, has low efficiency and results in insufficient supply of millet. In this paper, we systematically investigated effects of moisture content and varieties of millet on its physical parameters, effects of millet varieties and compression azimuth on the compression mechanical properties (including yield load, deformation, failure energy and apparent elastic modulus) of millet, and effects of compression azimuth on crack formation of millet. The study results are expected to provide the basis for the design and optimization of millet harvester and related processing machinery. In this paper, the 1000-grain weight was measured by an electronic balance, the triaxial sizes by a vernier caliper, and the moisture content by fast grain moisture analyzer for four millet varieties: Zhangza-10, Dungu, Jingu-21, Changgu. The sphericity of the millet, the arithmetic mean diameter and the geometric diameter were calculated using the triaxial sizes. The compression tests were carried out along X, Y, Z axis using a texture analyzer and the data were analyzed by SAS statistics software. The yield load, deformation, and failure energy were obtained from the force-distance curve measured by a texture analyzer. At the same time, the apparent elastic modulus was calculated according to the Hertz formula. The experimental results were summarized as follows in six categories. 1) For the physical parameters of the millet, with a moisture content between 15.2% and 25.1%，the length, width, height, 1 000-grain weight, average diameter and geometric mean diameter of millet grain decreased as the moisture content decreased. The millet length, width and thickness range from 2.028 to 2.112 mm, 1.818 to 1.931 mm, 1.413 to 1.513 mm, respectively. The sphericity of millet was more than 84%; the arithmetic mean diameter varied from 1.750 mm to 1.852 mm; and the geometric mean diameter 1.732 mm to 1.834 mm. Therefore, the shape of millet can be regarded as ellipsoid. There were significant differences (P<0.001) in the triaxial sizes, 1000-grain weight, sphericity, arithmetic mean diameter and geometric mean diameter among different varieties. When the moisture content of millet was about 25%, the 1000-grain weight of Jingu-21 was 3.473 g, which was the heaviest millet, while Zhangza-10 was 3.264 g, which was the lightest millet. The moisture content has a negligible effect on the sphericity. The effect of varieties on sphericity was significant (P<0.001). 2) For factors on the compression mechanical properties, the influence of moisture content, compression azimuth, and variety on the compression mechanical properties were significant (P<0.01). The significant factors affecting the compression mechanical properties were compression azimuth, moisture content, and variety in a sequence from the most significant to the least significant. 3) For the effects of the moisture content, for the same kind of millet, the yield load and apparent elastic modulus decreased as the moisture content increased during compression in X, Y, Z axis. The yield load decreased slowly when moisture content ranged from 20.9% to 25.1%. The deformation and failure energy first decreased and then increased as the moisture content increased. For the same azimuth compression, the better the quality of the millet, the more compact the internal structure, and the smaller the deformation. 4) For crack formation of the millet: on the X axial, a crack started from the crest of the grain along the junction of embryo and endosperm, and then extended throughout the X axis. On the Y axis, a crack started from the connection point of grain and probe and the connection point of grain and base throughout the Y axis because of stress concentration. On the Z axis, a crack started from the junction of embryo and endosperm on the back to the ventral hilum along the weakest part of endosperm resistance extending throughout half of the grain. 5) For the effects of compression azimuth, the yield load increased in turn on the X, Y, and Z axis and the deformation and failure energy decreased on the X, Z, and Y axis in turn. The apparent elastic modulus of the millet increased in turn on the X, Y, and Z axis. This result indicated that millet was not uniform and it was an anisotropic body. 6) For the effects of millet varieties, with the same moisture content, the compression mechanical properties of Jingu-21, Dungu, Changgu and Zhangza-10 varied from large to small. This indicated that Jingu-21 had a relatively good compression resistance and quality. [ABSTRACT FROM AUTHOR]