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目的 探讨颞浅动脉-大脑中动脉端侧吻合术中不同临时阻断技术的效果及可靠性。 方法 回顾性分析2015年1月—2023年4月南方医科大学南方医院神经外科收治的接受直接搭桥术治疗的烟雾病患者资料，根据临时阻断策略的不同将患者分为3组：①有垫片、多阻断夹阻断组（multi-clips+rubber pad group，M+R组）；②无垫片、多阻断夹阻断组（multi-clips group，M组）；③无垫片、单阻断夹阻断组（single-clip group，S组）。比较组间临时阻断时间、受体动脉切开后有无渗血、术中穿支血管损伤以及术后新发脑梗死情况。 结果 共355例患者、360个大脑半球纳入分析，按大脑半球统计患者360例，其中男性188例，女性172例，平均年龄为（43.8±0.7）岁。其中M+R组45例，M组191例，S组124例。3组平均阻断时间：M+R组为（37.9±9.8）min，M组为（20.9±9.0）min，S组为（11.0±3.5）min，组间差异有统计学意义（P＜0.001）。阻断后受体动脉管腔内渗血以及术中穿支血管损伤发生率：M+R组为8.89%（阻断后受体动脉渗血4例），M组为14.66%（阻断后受体动脉渗血19例，术中穿支血管损伤8例，临时阻断部位有血栓形成1例），S组为5.65%（阻断后受体动脉渗血7例），组间差异无统计学意义（P>0.05）。术后新发脑梗死发生率差异无统计学意义（P>0.05）。 结论 单阻断夹阻断策略安全、有效，能显著缩短临时阻断时间，可以优先考虑作为颞浅动脉-大脑中动脉端侧吻合过程中的临时阻断策略。 Abstract: Objective To investigate the effects and reliability of different temporary occlusion techniques in end-to-side anastomosis of the superficial temporal artery-middle cerebral artery. Methods A retrospective analysis was conducted on the data of patients with Moyamoya disease who underwent direct bypass surgery in the Department of Neurosurgery, Nanfang Hospital, Southern Medical University, from January 2015 to April 2023. The patients were divided into three groups according to the different temporary occlusion strategies: ①multi-clips+rubber pad group (M+R group); ②multi-clips group (M group); and ③single-clip group (S group). Temporary occlusion time, presence of errhysis after recipient artery incision, intraoperative perforator vessel injury, and postoperative novel cerebral infarction were compared among the three groups. Results A total of 355 patients and 360 cerebral hemispheres were included in the analysis, and 360 patients were counted according to the number of cerebral hemispheres, including 188 males and 172 females, with an average age of (43.8±0.7) years. There were 45 cases in the M+R group, 191 cases in the M group, and 124 cases in the S group. The average occlusion time were (37.9±9.8) minutes in the M+R group, (20.9±9.0) minutes in the M group, and (11.0±3.5) minutes in the S group, with significant differences between the groups (P0.05). There was no significant difference in the incidence of novel cerebral infarctions postoperatively (P>0.05). Conclusions The single-clip occlusion strategy is safe and effective, which significantly shortens the temporary occlusion time, and should be prioritized as the temporary occlusion technique in end-to-side anastomosis of the superficial temporal artery-middle cerebral artery.

Copyright of Chinese Journal of Stroke is the property of Chinese Journal of Stroke Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Track skid and slip often occur, when the tracking chassis work in soft soil and uneven field. The accuracy of curved path tracking can inevitably deteriorate in automatic navigation. In this work, path tracking was designed to consider the track skid and slip in field conditions. Firstly, the coefficient of turning radius correction was derived to describe the skid and slip characteristics using the kinematic model of the tracked chassis. Then, the lateral and heading deviations were determined by the look-ahead model. Finally, a three-input fuzzy controller was established with the controller inputs of lateral deviation, heading deviation and turning radius correction coefficient. A dual-motor tracked chassis was designed to validate the model. The control hardware included two brushless DC motors, a motor driver, an STM32 microcontroller, and two photoelectric rotary encoders. In navigation, the position, heading and angular velocity of the chassis were measured by a high-precision RTK-GNSS and an MTi-30 inertial sensor. The measurement values were sent to the upper-level computer using a serial port. The path tracking was carried out to calculate the control signal, and then sent into the lower-level microcontroller. The tracking of the reference path was realized by the motor driver of the lower-level microcontroller on both sides. A field experiment was conducted on automatic navigation to verify the performance of a three-input fuzzy controller. The field was selected with a lot of weeds, where the soil was wet and sticky with a moisture content of 22.4%. There was the low flatness with some pits, bulges and hardened soil blocks that scattered throughout the whole field. The speed of the chassis was set to 0.6 m/s in navigation. The look-ahead distance proportional coefficient of the look-ahead model was set to 1.5. An initial lateral deviation of about 1000 cm was set for the correction. The results showed that the average response time of the control system was 6.79 s, while the average distance was 4.08 m. The tracking test of the U-shaped path was performed on the three-input fuzzy controller. The maximum absolute deviation, average absolute deviation and standard deviation of the straight-line and curve tracking section were 12.0 and 21.3 cm, 3.6 and 8.6 cm, as well as 4.4 and 8.4 cm, respectively. The curve tracking with the three-input fuzzy controller was compared with the conventional one, in order to further determine the path tracking accuracy under track skid and slip. The maximum absolute deviation, average absolute deviation and standard deviation of the conventional and three-input fuzzy controller were 31.1 and 22.4 cm, 8.3 and 7.4 cm, as well as 10.2 and 9.1 cm, respectively. Compared with the conventional, the three-input fuzzy controller was improved by 27.95%, 10.84 % and 10.78 %, respectively, in the maximum absolute deviation, average absolute deviation and standard deviation. The better control performance of the navigation system was achieved in the three-input fuzzy controller, indicating the reduced influence of track skid and slip. This finding can also provide a strong reference for the high-precision navigation of tracked chassis in soft soil environments in the field. [ABSTRACT FROM AUTHOR]

Ratoon rice is a typical cultivation to allow for the growth of another crop of rice using dormant seedlings from the previous harvest. Seedling, raising, and transplanting of double-season rice can be removed to reduce the harm from pesticide residues. Cultivated land quality can also be protected at a low cost. Additionally, the quality and fullness of the second crop of ratoon rice are superior to that of double-season rice. The planting area of machine-harvested ratoon rice has increased rapidly in recent years. Therefore, most research has been focused on the harvest technology and equipment of ratoon rice. Particularly, ratoon rice harvesting is required for the low rolling and high stubble retention for optimal agronomic conditions. The rolling of rice stubble during harvest in the main season can significantly reduce the yield of ratoon rice in the ratoon season. Once the lodging occurs at the mature stage of crop growth, it is detrimental to the harvesting yield and quality. Therefore, the optimal path of harvesting is crucial to improve the efficiency of grain production for better harvesting with minimal loss. Concurrently, the volume limit of the grain bin in the harvesters and the location of the unloading points also exert a significant impact on the loss of harvesting and low rolling of the ratoon rice. Therefore, it is necessary to design the harvest path of the ratoon rice harvesters for the maximum yield in the main season. The optimal path for high-quality agricultural machinery is crucial to saving time and energy, particularly for better operation efficiency and quality with less soil rolling. In this study, a path planning was proposed, called the harvester grain bin capacitated arc routing (HGBCARP). Two modules consisted of information processing and path planning. The information processing module was used to convert the operation information (such as farmland boundaries, unloading point positions, crop lodging directions, and area positions) into a processable data form, and then transmit it to the path planning module. The optimal path planning was obtained after the tasks, such as the direction division of the operation line, the optimization of the operation line traversal sequence, the generation of turning modes, and the calculation of the rolling area. An improved genetic algorithm was utilized to evaluate the performance of three new types of ratoon rice harvesters, as well as two traditional rice harvesters. Three parameters of the field test were taken as evaluation indicators, including the length of the driving path, the rolling area, and the amount of harvested grain. A comparative simulation was then conducted under three field conditions using rotary and HGBCARP harvesting path planning. It was found that the rolling area of the HGBCARP harvesting path was 11.79% to 27.20% less than that of the rotary type. The rolling area was reduced to increase the yield of the main season rice by 1.64% to 1.95%. Additionally, the HGBCARP harvesting path was found to reduce the rolling area by 7.25% to 20.09%, compared with the rotary type. Field harvesting experiments were carried out using an electric unmanned crawler chassis on various harvesting paths. The HGBCARP harvesting path was found to reduce the rolling area by 11.21% to 28.03% and the path length by 6.81% to 23.46%, compared with the traditional cattle tillage reciprocating and rotary harvesting paths. The high effectiveness was achieved in the HGBCARP path planning. This finding can also provide a valuable reference for intelligent operation path planning. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Automatic transplanting of plug seedling has limited for the two challenges. One is that the broken pot can be caused by the weak twining force between roots and soil, when the end of grippers is inserted into the pot to pick up the seedlings; Two is that the low success rate of seedling picking in the stem-pulling seedling picking mechanism, when the seedling claws clip and pull the stem, due to the weak adhesion force between the pot and the plug. In this study, a seedling picking device was proposed with ejecting pot-clamping stem. The picking up seedling was as follows: The pot was ejected by rod to clip out from the seedling, and then the stem was clamped by seedling clip, while seedling was pulled out of plug tray, seedling shift and releasing clip throwing. A series of tests were carried out on the structure design, the device trial and optimization. Taking "Zhongnong Luheng line pepper 363" plug seedlings aged 35 to 50 days as the object, the stem of plug seedling was tested to obtain the characteristic parameters, stem tensile and stem radial compression mechanical properties; The pot of plug seedling was tested to verify the parameters. The result shows that the maximum drawing force was 3.54-5.38 N, the elastic modulus of the pot was 30.64×10−3 MPa, the deformation at the yield point of the pot was 10.87 mm, and the pressure resistance was 12.33 N. The path was optimized for the picking up and throwing seedlings. The optimal path of picking up seedlings stretching along Y direction was 33.98% shorter than that along X direction. The stress models of the pot and stem were established during ejecting and clamping, according to the stem and pot physical properties of pepper plug seedlings. The key parameters of seedling picking up device were designed, including the seedling tray conveying device, the top ejecting device, and the seedling picking up mechanism. An optimal combination of parameters was achieved, where the diameter of the ejecting rod was 15 mm, the height of ejecting pot was 10-20 mm, the height of clamping stem was 20 mm, and the width of the clamping sheet and the width of the seedling clip were both 10 mm. Seedling picking up experiment was carried out on the test bench, where the average total height of plug seedling was 216 mm. The pot moisture content, seedling pick-up frequency, and the height of pot ejecting were used as the influencing factors for the seedling pick-up L9(34) orthogonal experiments. The better growth of the plug seedlings was achieved in the picking up from the ejecting pot-clamping stem. The optimal horizontal combination of factors was determined as well. The damage rate of pot was 1.98% and the success rate of picking up seedling was 98%, when the moisture content was 45%, seedling pick-up frequency was 60 plants/min, and the height of seedling ejecting was 10 mm. Field test was carried out at the working speed of 10 ~ 30 m/min and the picking up seedling frequency of 60 plants/min. The average success rate of seeding pick-up was 93.05%, and the qualified rate of plant spacing was 88.17%. This seedling pick-up device shared the stable seedling pick-up and low damage rate, particularly for the transplanting plug seedlings, such as pepper and tomato. The planter can be expected to install the transplanter for the high-efficient picking up of seedling. [ABSTRACT FROM AUTHOR]

This study aims to separate the soil and corm while harvesting water chestnuts on dry land. A spring roller device of soil-corm separation was also designed for the water chestnut harvester, in order to reduce the injury rate of water chestnut. Positive and negative rotating springs were arranged side by side. During the operation of the harvester, the soil-corm mixture was dug out and passed through the lifting device and rubber-roller soil removal device, and then fell into the spring roller soilcorm separation device, where the water chestnuts were further separated from the soil under the vibration and rubbing of the rotating positive and negative spiral spring rollers. The kinetic analysis was performed on the relative motion of the water chestnut and spring roller. The influencing factors on the separation performance were determined as the spring outer diameter, pitch, adjacent spring spacing, height difference and spring speed, line diameter and operation speed. The simulation of soilcorm separation was carried out to optimize the operating performance of the spring roller. The model was then established using EDEM software, including three particles: large soil clods, water chestnuts and fine-grained soil. A single-factor test was carried out on the structural and working parameters of the spring roller, in order to clarify the influence of each factor on the soil-corm separation. Taking the sieving rates of water chestnut and soil as the test indexes, the quadratic regression orthogonal test was also carried out. An optimal combination of parameters was obtained for the spring roller, where the outer diameter was 100 mm, the pitch was 30 mm, the spacing was 9 mm, and the rotational speed was 420 r/min. The better performance was achieved, where the sieving rates of water chestnut and soil were 80%, and 80.69%, respectively. The verification tests were then conducted to compare the prediction of the model. The average relative errors of water chestnut and soil sieving rate were 2.09%, and 2.42%, respectively. The simulated harvesting and one-way tests were carried out to take the test indexes as the rates of the open, the injured, the peeling, and the digging, with the soil moisture content and spring speed as test factors. Among them, the water chestnuts were pre-buried into the soil layer and then harvested. Three wire diameters of springs of 10, 12, and 14 mm were also selected to evaluate the mud-fruit separating of spring rollers. It was found that the 12 mm wire diameter spring shared both better vibration performance and lower damage rate of water chestnut. Actual harvesting tests were conducted to test the performance of the soil-corm separating device. The performance of the water chestnut harvester was measured as follows: the operating speed was 0.21 m/s, the operating efficiency was 0.19 m²/s, the soil breaking rate was 75.61%, the open water chestnut rate was 82.42%, the injured water chestnut rate was 14.73%, and the peeling water chestnut rate was 7.01%. The soil crushing and soil-corm separation were enhanced with the increase in rotational speed. However, the injury rate of the water chestnut also rose, and the rotational speed of the spring roller should not be more than 244.5 r/min. The broken soil rate was outstandingly improved with the reduction of soil moisture content, but the injured rate of water chestnut increased as well. The damage rate of water chestnut more outstandingly increased with the decrease of soil moisture content at the soil moisture content of 15.77% to 17.44%, compared with the soil moisture content of 17.44% to 19.40%. The finding can provide a strong reference for the development and optimization of water chestnut harvester. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Influenced by the ecological environment and other factors, the quality and yield of lotus root have been seriously affected by the occurrence of diseases and insect pests in recent years. With the improvement of living standards and the development of the lotus industry chain, people are looking for green food, high-yield and high-quality products. Nowadays, many farmers and planters are unable to accurately identify the diseases and pests of lotus due to lack of professional knowledge of diseases and insect pests control. There is a shortage of efficient, low-cost and automatic identification technology for the prevention and control of lotus diseases and insect pests. The diagnosis and identification of diseases and insect pests are of great significance for the prevention and control of diseases and insect pests in lotus fields. Over the past few years, deep learning technology has been widely used in the field of plant diseases and insect pests recognition to automatically extract the features of plant diseases and insect pests. In order to achieve an efficient and accurate diagnosis of lotus leaf diseases and insect pests, lotus leaf diseases and insect pests dataset was constructed and preliminary experiments were constructed on AlexNet, VGG-16, ResNet50, ResNeXt50, and DenseNet121 models. The experimental results indicated that DenseNet121 has the best performance on the dataset, lotus leaf diseases and insect pests identification model based on improved DenseNet was improved. Firstly, different methods for dynamic data enhancement were compared in this paper. The results show that resizing and randomly resizing the image is more accurate than directly resizing to the same size. The loss of detail information in part of the image is caused by over-compressing the image size, which affects the model’s recognition effect. The accuracy of the model was increased from 81.47% to 85.01% by using the data enhancement method of resize, random resized crop, random horizontal flip and random adjust sharpness. AdaMax optimizer was used to replace Stochastic Gradient Optimization optimizer and the accuracy of DenseNet model has been improved by 3.04 percentage points. The Stem block uses multi-layer small convolution for fast dimensionality reduction and a branch structure to combine convolution and maximum pooling. It improves the ability of the model to extract shallow features at a lower operating cost. The Squeeze and Excitation attention mechanism block and sharpen cosine similarity convolution were introduced in the Denselayer of the Dense Block and the Transition Layer. This method improved the recognition ability of the model to lotus leaf diseases, and verified the effectiveness of sharpen cosine convolution to improve the performance of the model. Transfer learning was performed on the Plantvillage dataset. The accuracy of the improved model is 91.34%, which 9.87 percentage points higher than before improvement and optimization. In order to solve the problem of monitoring diseases and insect pests in lotus fields, the improved model was applied to the identification of lotus field diseases and insect pests in UAV images. The calibration area of lotus leaf was cut and predicted by reasoning, then different masks were generated according to the model prediction results and added to the UAV image to generate a distribution map of lotus field diseases and insect pests. The recognition of lotus field diseases and insect pests in the UAV image was investigated, automatic classification and recognition of leaf spot, viral disease, Spodoptera litura, lotus Sclerotium leaf rot and lotus rhizome rot were realized. It provides a new method for efficient and accurate identification and dynamic monitoring of lotus diseases. It also supplies information supports for variable pesticide application and flight path planning in plant disease prevention and control based on UAV. [ABSTRACT FROM AUTHOR]

Allium chinense, as a characteristic vegetable, is exported to Southeast Asian countries such as Japan and South Korea with remarkable economic benefits. Aimed at the problems of Allium chinense planting, main including high labor intensity and artificial planting process cost, a spoon clip seed metering device for Allium chinense was designed. It consists of a seed metering disc, spoon, seed taking and discharging cam, seed box, mounting plate, and other components. The working principle of the spoon clip seed metering device for Allium chinense, and the mechanism of seed taking, seed carrying, and seed discharging were expounded by analyzing the stress state and movement state of Allium chinense seeds in the working process of seed metering device. The seed taking process of the seed metering device was simulated using discrete element simulation software to optimize the spoon for different structures. The Plackett-Burman test method was used to select the significant factors of spoon diameter, spoon depth, start angle of seed taking, the proportion of seed height, and speed of seed taking. Qualified rate of seed taking and missing rate of seed taking were used as test indexes. Orthogonal regression tests were carried out with spoon diameter, start angle of seed taking, and proportion of seed height as experimental factors. Regression models of qualified rate of seed taking and missing rate of seed taking were established, and parameters were optimized. Field test were conducted to examine the field seeding performance of the seed metering device for Allium chinense based on obtaining optimal parameters. Simulation results show that the type of spoon has a high significance on the qualified rate of seed taking (P<0.01). Qualified rate of seed taking of the round spoon is more excellent than the other two spoons at different speeds, with an average value of 91.14%, and the round spoon is selected as the preferred structure through comprehensive analysis. According to the results of the Plackett-Burman test, diameter of spoon has a highly significant effect on the missing rate of seed taking (P<0.01), and proportion of seed height has a significant effect on both the qualified rate of seed taking and missing rate of seed taking (P<0.05). The analysis of the effects of the test factors and their interactions on the test indicators in the Box-Behnken test shows that the test regression model is highly significant (P<0.01). The interaction of spoon diameter and start angle of seed taking have a significant effect on the qualified rate of seed taking. Under the condition that other factors are determined, the qualified rate of seed taking increases with the increase of pickup diameter and then decreases. The qualified rate of seed taking decreases with the increase of the start angle of seed taking for smaller spoon diameters and increases with the increase of the start angle of seed taking for spoon diameters larger than 25 mm. The optimal parameters are as follows: spoon diameter is 27mm, start angle of seed taking is 30°, and proportion of seed height is 92.5%. Under the optimal parameter combination, the filling qualified rate and missing rate of seed taking were obtained, they were 91.17% and 6.17% respectively, which were consistent with the predicted results of the model. Observations of the field test process indicate that the seed metering device can complete the whole process of seed taking, seed carrying, and seed discharging in the field environment. The results of the field seeding test show that the average seeding qualified rate is 63.10%, and the average multiples rate and seeding missing rate are 12.76% and 24.14%, respectively, at the forward speed of 0.1-0.2 m/s. According to the operating quality for single seed metering device can satisfy the field operation. However, stability and efficiency can still be further optimized and improved. The research can provide a reference for the research and design of planting machinery for Allium chinense. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Agricultural University is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water caltrop is one of the annual herbaceous aquatic vegetables in the Lower-and-Middle Section of theYangtze and Pearl River Delta region in China. There is the high nutritional and medicinal value of water caltrop. Among them, the stems and leaves can be used as the green manure or fodder, the petioles and the ripe fruits as the vegetables or starch, the fresh and tender flesh as the raw fruit, as well as the shell can be used to extract the functional ingredients, such as natural pigments. The kernel of water caltrop can also be fabricated into the popular cans, the pickled bags, and special commodities. Nevertheless, the kernel shelling can be the most difficult and the longest duration in the postharvest processing of water caltrop, including the cleaning, grading, shelling, and packaging. The current shelling of fresh water caltrop also depends mainly on the manual operation, due to the irregular shape, hard shell, and uneven surface. The manual shelling cannot fully meet the large-scale production in recent years, particularly for the high labor intensity, low efficiency, as well as the high damage rate with the perishable meat after damage, unfavorable storage and subsequent processing. It is still lacking on the automatic shelling machinery of water caltrop in China at present. More than 90% of the water caltrop products are the raw materials without shelling. A high demand can also be required for the kernel of water caltrop as the high value-added products. Therefore, it is of great significance to clarify the shelling mechanism and the mechanized production, especially with the increase of planting area and output of water caltrop industry. In this study, a clamping sheller was designed for the fresh water caltrop. The overall dimensions and mechanical performance parameters of the water caltrop were collected from the producing base in the Xishui County, Hubei Province, China. According to the configuration and working principle of the whole machine, the structural parameters of the key components were determined, such as the clamping plate, transversal cutting blade, elastic pressing, and shelling device. The working parameters of the transversal cutting blade was analyzed to simulate the motion of water caltrop in the transversal cutting device using ANSYS explicit dynamics. A transversal cutting test was performed on the prototype of the clamping sheller for the fresh water caltrop. The working parameters of the transversal cutting device were also optimized by Design Expert 12.Theresults showed that there was a significant impact of the maturity, conveying, and blade speed on the shell cutting rate, but no significant impact was found on the loss rate of water caltrop kernel. An optimal combination of parameters was achieved in the maturity value of 1.000 01, the conveying speed of 0.100 01 m/s, and the blade speed of 999.981 r/min. The average shell cutting rate and the loss rate of water caltrop kernel were 79.41%, and 9.82%, respectively. Therefore, the optimum working parameters of the shelling device were as follows: the maturity value of 1.008 9, the slow roll speed of 58.862 7 r/min, and the line speed ratio of 1.490 66. The average shelling rate was 66.52%, whereas, the average damage rate of water caltrop kernel was 12.83% in this case. This finding is expected to provide a strong reference for the shelling machinery of fresh water caltrop. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water chestnut is an important aquatic vegetable, particularly with an annual output of more than 800 000 tons in China. The underground expanded bulb of water chestnut can be eaten fresh or cooked. The edible part of water chestnut has a crisp, sweet, and juicy taste, with many kinds of nutrients. The cuticle of water chestnut needs to be peeled off before eating. A large number of cutting methods can often be adopted to ensure the removal rate of the water chestnut from the peel. However, the complicated shape of the water chestnut can result in very little remaining pulp after peeling, indicating serious loss. There are also serious health and safety hidden hazards in manual peeling. There is no specific peeling device of water chestnut machinery at present. Moreover, the bud and root can be firstly removed for the mechanical peel of water chestnut. In this study, a rotary blade synchronous cutting device was designed for the simultaneous removal of the root and bud of water chestnut, according to the previous peeling, such as corn stalk, cotton, and sugarcane. The positions of the water chestnut were limited by the weight of the water chestnut and the structure of the device. The rotating blade group was also developed to simultaneously cut the bud and root. The non-clamping design was adopted to simplify the working process for the high efficiency of the device. A theoretical analysis was made on the number of holes in the disk, the geometry, and position of the rotary blade, as well as the relationship between the rotary blade and the disk. As such, the water chestnut was fixed in the locating hole. A kind of saw-tooth rotary cutting tool was designed to reduce the cutting force of the bud and root of the water chestnut. The simulation and optimization experiments were carried out using EDEM software, particularly with the response surface test using the Box-Behnken principle. Design-Expert 13 software was also used to fit the experimental data for the quadratic regression. The optimal parameters were achieved as follows. The length of the saw tooth base was 5 mm, the tooth height was 15 mm, and the cutting speed was 0.103 0 m/s. A force measuring device was also selected to verify the reliability of the simulation under the best parameters. The results showed that there was a relative error of 13.3 % between the measured and the simulation. The errors were attributed to the simplified force measuring device was not identical to the experimental one, particularly for the structural differences, and there were inevitable precision errors in the process of machining and installation. More importantly, the optimization experiment of locating the hole was carried out for the clamped and fixed water chestnut, in order to reduce the oblique cut under the resultant force in the actual running. The BBD response surface test was carried out with the minimum difference of oblique height as the response value, while the location-hole parameters and cutting speed as the influencing factors. The optimal parameters were achieved, where the arc depth, arc pitch, and cutting speed were 8.23 mm, 5 mm, and 0.103 0 m/s, respectively. The predictive height difference of the model was 4.1 mm under the optimal parameters, indicating that the test result was consistent with the predicted. Consequently, the cutting force and the height difference of oblique cutting were tested to optimize the working parts of the device. The finding can also provide a strong reference for the cutting device of the root and bud of water chestnut. [ABSTRACT FROM AUTHOR]

Water chestnut has been one of the most important aquatic vegetables in Asian countries. Annual production of more than 800 000 tons can be found in the south of the Yangtze River Valley. The edible flesh of the water chestnut is the crisp and tasty bulbous underground with a smooth reddish-brown surface. However, the current deep-processing of the water chestnut completely depends on manual work. The water chestnut industry has been severely limited to labor-intensive, high-cost, and small-scale production at present. It is very necessary to develop the agricultural machinery for the large-scale production of water chestnuts. Fortunately, discrete element simulation (DEM) can be widely used for the optimal design of mechanized progress. In this study, a DEM model was established to determine the key parameters in the peeling and slicing process of water chestnut using the calibration of EDEM software. A series of virtual calibration experiments were conducted to obtain the accurate shape of fresh water chestnut using 3D scanning reverse modeling. The physical tests were carried out for the geometric size of the water chestnut, the parameters of mechanical properties (density, Poisson's ratio, modulus of elasticity), and the basic contact parameters (coefficient of collision recovery, coefficient of static friction, and coefficient of dynamic friction) between a water chestnut and stainless steel. The shear test showed that the average of the maximum force of the blade on water chestnut measured by texture analyzer was 67.2 N, taking as the reference of the virtual calibration experiment. A Hertz-mindlin with the bonding model was established for the water chestnut in EDEM software. A virtual calibration experiment was designed with the shear stress of water chestnut as the evaluation index. A single factor test was used to determine the influence range of each factor, including the particle contact radius, normal stiffness per unit area, shear stiffness per unit area, critical normal stress, critical shear stress, and bonded disk radius. Among them, the normal stiffness per unit area, shear stiffness per unit area, and bonded disk radius were selected as the significant factors after the two-level test. The steepest climb test combined with the response surface (Box-Behnken Design) test was utilized to further reduce the range of the significant parameters. The optimized results demonstrated that the total model decision coefficient R2 of quadratic regression was 0.992 2, indicating a better fitting performance. An optimum combination of parameters was obtained with the objective of the minimum shear force: the normal stiffness per unit area was 1.185×108 N/m3, the shear stiffness per unit area was 9.091×107 N/m3, and the bonded disk radius was 1.655 mm (the rest of the other non-significant factors was the median), the particle contact radius was 1.6 mm, the critical normal stress was 10.0×106 Pa, and the critical shear stress was 10.0×106 Pa. The optimized parameters were simulated to verify by the field measurement, where the relative error between the simulated value and the measured maximum shearing force was 0.89%, indicating the correct model and reliable calibration parameters. Different blade curves were also used in the EDEM software and texturing instrument, in order to verify the generality of water chestnut modeling. The relative error between simulation and measured values was not more than 7.41%. The more stable stress curve of the convex blade without the sudden change of force can be expected to prolong the serving life of the blade. The convex edge can greatly contribute to reducing the maximum force in the process of water chestnut cutting. The finding can provide a strong reference for the design of various devices during water chestnut production. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Forensic Medicine / Fayixue Zazhi is the property of Journal of Forensic Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mechanizedfertilization has widely been one of the most important steps for the highyield of crops.In this study,a centrifugal side throwing fertilizer spreader was designedforthe lotus root field. Firstly, atheoretical model was established for the force of a single fertilizer particle on the blade. The main parameters were then determined for the particle motion,such as the rotating speed of the fertilizer tray, theblade inclination angle, and the blade deflection angle. Secondly, EDEM discrete element simulation software was utilizedto optimize the performance of the spreader.A single factor test was carried out, where the fertilizer feed rate and the above factors were taken as the influencing factors. The results showed thatthe weightdistributionof fertilizer increasedfirst and then decreasedin a single statistical area when taking the center of the spreader as the originalong the throwing direction. Specifically, the quality of fertilizer with the most distribution in a single statistical region was called the peak value, and the distance between this region and the fertilizer spreader was called the peak distance, to accurately quantify the distribution index of fertilizer. The rotating speed of the fertilizer tray and the blade inclination angle poseda significant impact on the peak value and peak distance of fertilizer distribution, whereas, the blade deflection angle and feed rate onthe peak value.An orthogonal rotation simulation test was carried out with the uniformity variation coefficient and peak distance as the evaluation indexes.It was found that there was an extremely significant influence on the uniformity variation coefficient (P<0.01), including the rotating speed of fertilizer tray,the blade inclination angle, the blade deflection angle,the interaction between them,the interaction term between the inclination angle of blade and feed rate,as well asthe quadratic term of blade inclination angle.There was an extremely significant effect on the peak distance (P<0.01), including the rotating speed of fertilizer tray, the blade inclination angle, and the quadratic term, the quadratic term of feed rate.Design-Expert software was utilized to optimizethe structure of the spreader.The blade structure parameters were then calculated to minimize the uniformity variation coefficient, when the peak distance was 10 and 21 m, the blade inclination, and deflection angle were 8.5°, 17.5°, 11.5°, and -1.9°, respectively.Subsequently, the simulation and actual fertilizer application were carried out to evaluate the performance of the fertilizer spreader with the optimalstructural parameters.The simulation results show that the uniformity variation coefficient, peak distance, and working width were 19.43%, 21m, and 29m, respectively,when the rotating speed of the fertilizer tray was 1 250 r/min, and the feed rate was 0.316 kg/s. By contrast, the specific parameters in an actual contrast testwere 21.95%, 18.6m, and 24.5 m, respectively, wherethe errors with the simulation were 12.95%, 11.42%, and 15.51%, respectively. A performance test of fertilizer spreader was carried out with large particle urea, compound fertilizer, and phosphorus fertilizer commonly used in lotus root field topdressing. The results showed that the operation effect of large particle urea was better at 1 300 r/min, feed rate of 0.15kg/s, and operation width of 24m. At this time, the uniformity variation coefficient was 24.56%. The analysis of variance showed that the rotating speed of fertilizer tray,feed rate, fertilizer type, and the interaction term between fertilizer type and feed ratepresentedan extremely significant impact on the coefficient of variation (P<0.01). The rotating speed of fertilizer tray, feed rate,and type presentedan extremely significant impact on the operation width (P<0.01).The finding can provide an important reference for the design of fertilizer spreading machinery in the lotus root field. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Forensic Medicine / Fayixue Zazhi is the property of Journal of Forensic Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rice is one of the main food crops for more than 50% of the world's population. Mechanized rice direct seeding was roughly divided into broadcast seeding, drilling and hill seeding. The broadcast seeding was not conducive to the field growth and management, where the seeding precision was low, the distribution of rice seeds was irregular in the field, and the uniformity of seedling emergence was not good. In the drill seeding, the field distribution was better regular than that in the broadcast seeding. Since about 50% of rice planting area in China is hybrid rice at present, the drill seeding cannot meet the requirements of hybrid rice seeding, particularly suitable for the conventional rice because of its large seeding rate. The hybrid rice has stronger tillering ability and higher yield, compared with the conventional rice. Furthermore, only 3-5 seeds/hill is needed to form high-yield structure, when the mechanized direct seeding was adopted. In this study, a double-cavity pneumatic precision direct seeder was designed for the hybrid rice, with the seeding rate of 3-5 seeds/hill as the goal, thereby to meet the requirement of hybrid rice direct seeding in the field. The seeder was mainly composed of a double-cavity pneumatic seed metering device, gasoline vortex pump, negative pressure pipeline, ditching equipment, and transmission system, where the seed metering device was introduced, and the transmission system was designed. The vacuum pump was also selected, where the gradient reducing pipeline was designed to provide the air flow of negative pressure, according to the negative pressure of seed metering device. Taking the hybrid rice Yongyou 4949 as experimental materials, a field test was carried out under the various negative pressure of sucking seed, and forward speed of seeder (i.e., the rotation speed of sucking seed plate). An attempt was made to explore the effects of sucking seed negative pressure and the forward speed on seeding precision of double-cavity pneumatic rice precision direct seeder. As such, a new type of pneumatic direct seeder was designed with a double cavity for rice precision seeding, according to the requirement of direct seeding of hybrid rice in the field. A field experiment was also carried out to obtain the best working parameters, after the design for the main working parts of the seeder. The results showed that the average seeding qualified rate (3-5 seeds/hill rate) of seeder was 91.04%, the probability of 0-2 seeds/hill was 2.23%, the probability more than 5 seeds/hill was 6.73%, the average number of seeding was 4.16, and the variation coefficient of seeding qualified was 1.24%, when the negative pressure of sucking seed was 3.2 kPa and the forward speed of seeder was low (0.2-0.4 m/s). Two factors can be contributed to the values of parameters in field tests lower than those in laboratory tests. The uneven mud surface can determine the field work of seeder, due to the complex environment of field seeding can be detrimental to the performance of seed sucking, particularly on the vibration of seeder. In the uneven distribution of negative pressure, there was a significant influence on the seeding precision of seeds metering devices, where the others would not be able to achieve the optimal negative pressure of seed sucking, when some of seed-metering devices reached. In the field test, the probability of 0 seed/hill was 0. Compared with the original seeder with the single cavity and single sucking plate, the pneumatic rice precision direct seeder with the double cavity can effectively improve the probability of 0 seed/hill. The seeding precision can meet the requirement of direct seeding of hybrid rice in the field. The finding can provide a sound reference for the precision direct seeding and equipment of hybrid rice. [ABSTRACT FROM AUTHOR]

The decreased progressive sperm and the increased sperm malformation are the most direct causes of male infertility. Under the normal physiological condition, the low level of reactive oxygen species (ROS) in the male reproductive system plays an important role in sperm chromatin coagulation, energy gain, movement and cell defense. However, the high level of ROS destroys the balance between oxidation and anti-oxidation in the body, forms oxidative stress, and negatively affects the movement, morphology of sperm and stability of the sperm DNA, and reduces certain functions and fertilization potential of the sperm. Inositol (MI) and its derivatives disseminated widely in mammalian tissues and cells play an important biological role. MI is involved in a series of complex fertilization processes, such as sperm survival, induction of activation, fertilization, acrosomal reaction and mutual recognition with oocyte membrane. MI can be used as antioxidants for adjuvant treatment of male infertility. Studies have showed that the in vivo supplement of MI can significantly improve the semen quality of patients with asthenospermia, and that the in vitro supplement of MI can significantly improve the sperm vitality of those patients. In this paper, the application of inositol in infertile men will be discussed. [ABSTRACT FROM AUTHOR]

As one of the rice varieties, ratoon rice has the advantages of making full use of temperature and light resources, saving seed, labor, water and pesticide, improving land use efficiency, increasing production and income. The first crop of ratoon rice is often harvested in wet and soft soil and requests high stubble and low rolling rate and degree. However, the rolling rate of common harvester is as high as 40%-50%, which seriously affects the yield of ratoon rice, resulting in significant reduction of economic benefits of ratoon rice production. According to the needs of mechanized harvest and low rolling rate of first crop of ratoon rice, a double-channel feeding harvester for ratoon rice was designed according to the growth characteristics of ratoon rice based on previous researches and theoretical methods proposed by the research group. The machine was mainly composed of a tracked chassis, a header, two sets of threshing and cleaning devices and straw crushers which were bilateral symmetry, a grain bin, an engine and transmission system, and the harvester could realize the process of straw separating, plant-poking, cutting, transporting, threshing, cleaning, straw crushing, grain transporting, grain holding and grain unloading in one time. Compared with the common harvester, by adopting the structure that two sets of working parts share one walking chassis, the weight of the double-channel feeding harvester for ratoon rice was reduce and the damage degree of rolling on the rice stubble was low. According to the harvest rolling model of ratoon rice harvester, the structural parameters were set as the cutting width was 3 000 mm, the track gauge was 1 500 mm, the track width was 400 mm and the grounding length was 1 800 mm. A special header with two channels was designed, which shortened the distance of straw transportation, mitigated the blocking of header, and effectively balanced the power consumption and reduced the vibration by transferring the power separately. Two sets of independent telescopic finger mechanism was adopted which could avoid deformation due to long eccentric shaft, and it was determined that the initial circumferential angle of the two spiral blades in the middle of the two-way spiral conveyor was 180° based on the theoretical analysis. To ensure that the long straw after threshing and cleaning was crushed and scattered to the harvested area, by analyzing the scattering range of straw crusher, it was ascertained that the inclination angle of the outer plate of the tail plate was 8.2°, the inclination angle of the inner plate was 6°, and the angle between the upper cover plate and the vertical direction was 63°. Longitudinal axial threshing cylinder was adopted for threshing. Through analyzing the rolling rate and productivity, it was determined that the available volume of grain bin was 1.5 m³, which could hold 900 kg grain. Harvesting performance was tested according to relevant standards, the major performance evaluation indicators consisted of working speed, feeding rate, loss rate, impurity rate, crushing rate and productivity. The PL60 4LZT-6.0ZC1 harvester of ZOOMLION was used as a contrast. It was suggested from the field test that this machine had stable performance and smooth operation. The tail straw crusher could guide the broken straw into the rolling area, the working speed could reach 0.8 m/s, the feeding rate was 4.6 kg/s, the total loss rate was 2.1%, the impurity rate was 0.4% and the crushing rate was 0.2%. The straight rolling rate was as low as 26.7%, which was 16.2% lower than that of the contrast. The yield of ratoon rice in the first season was 10 175.4 kg/hm², the yield in the second season was 6 013.5 kg/hm², and the total yield in the first and second season was 16 188.9 kg/hm². In control area harvested by the common harvester, the yield of ratoon rice in the first season was 10 175.4 kg/hm², the yield in the second season was 4 854.6 kg/hm², and the total yield in the first and second season was 15 030 kg/hm². Compared with the common harvester, the yield increased by 23.9% (1 158.9 kg/hm²) in the second crop harvested by the double-channel feeding harvester. This research could provide valuable reference for the research and extension of ratoon rice mechanical harvesting technology in the middle and lower reaches of Yangtze River. [ABSTRACT FROM AUTHOR]

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Forensic Medicine / Fayixue Zazhi is the property of Journal of Forensic Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to realize field precision seeding and raise the utilization of seeding machine, a kind of double-cavity side-filled precision seed metering device for rice was designed, and a new seed-retaining structure was proposed, which used the brush to clean and protect seeds. The working principle seed metering device was analyzed and the related parameters were established. Qualification ratio, resowing ratio, missed seeding ratio and breaking ratio were regarded as the evaluation index. The study objects were "Peizataifeng" (hybrid rice) and "Huanghuazhan" (conventional rice), which were pre-germinated and their moisture were respectively 22.47% (wet basis) and 21.66% (wet basis). The single cavity of seed metering device was used to seed the hybrid rice and the double cavities of seed metering device were used to seed conventional rice with the different rotational speed of seeding axle, the different forward speed of conveyor belt, and the regular throwing-seed height. The experimental results showed there existed optimal combination parameters for the capability of the metering device to meet the needs of precision seeding, which were that the rotational speed of seeding axle was 25 r/min, the forward speed of conveyor belt was 1.0 m/s, the hole distance was 150 mm, the throwing-seed height was 150 mm, the angle between the type hole central line and the seeding disc axis line was 20°, and the angle between the radial direction of long axis for the section of type hole and the radial direction along the end face of the seeding disc was 90°. under the optimal combination parameters, the qualification ratio (2-4 seeds per hole) of seeding "Peizataifeng" (hybrid rice) with single cavity was 87.04%, the resowing ratio (0-1 seed per hole) was 2.96%, the cavity ratio (0 seed per hole) was 3.33%, and the breaking ratio was 0.40%. Meanwhile, the qualification ratio (5-8 seeds per hole) of seeding "Huanghuazhan" (conventional rice) with double cavities was 70.26%, the resowing ratio (0-4 seeds per hole) was 0, the cavity ratio (0 seed per hole) was 0, and the breaking ratio was 0.06%. The single cavity and the double cavities of seed metering device to seed different rice type, the change trends of the qualification ratio, the resowing ratio, the missed seeding ratio and the breaking ratio were consistent. The experimental results showed that the qualification ratio (2-4 seeds per hole) of seeding "Huanghuazhan" was more than 84.13%, the cavity ratio (0 seed per hole) was less than 3.33%, and the breaking ratio was less than 0.47%, when the rotation speed of seeding axle ranged from 10 to 25 r/min. Because the seed metering device has a double-cavity structure, it can seed with single cavity or double cavities, and the adjustment of seeding quantity is convenient. The study provides a basis for the design of double-cavity type seed metering device. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)