Design Principles of the Non-smooth Surface of Bionic Plow Moldboard

The diverse non-smooth body surfaces to reduce soil adhesion are the evolutional results for the soil animals to fit the adhesive and wet environment and can be used as a biological basis for the design of bionic plow moldboard. The model surfaces for bionic simulation should be taken from soil animal digging organs, on which the soil motion is similar to what is on the surface of moldboard. By analyzing the distribution of non-smooth units on the body surface of the ground beetle jaw and the soil moving stresses, the design principles of the bionic moldboard for the local and the whole moldboard were presented respectively. As well, the effect of soil moving speed on reducing adhesion, the dimensions relationship between soil particles and non-smooth convexes, the relationship between the enveloping surface of non-smooth convexes and the initial smooth surface of the plow body, and the convex types of the sphere coronal and the pangolin scales,etc.were discussed.

Evaluation of plow system performance in long-wall mining method using particle flow code

The underground or open-pit methods are used for the extraction of mineral resources,each of which is divided into different categories.Coal is one of the mineral resources,which is exploited either by the surface or the underground methods.The long-wall mining is one of the methods for the underground coal mining.In this method,which is a mechanized one,some machines such as the shearer or plow are used for the mining.The coal mine in Parvadeh,Tabas is a mechanized mine that is extracted by the long-wall mining.The modeling with particle flow code software was used in this mine for the evaluation of plow performance using the coal specifications.In this regard,the sample was first calibrated by sampling from the Parvadeh coal mine and performing the uniaxial and Brazilian tests on the model.Then,the modeling was done by constructing the model and using the variables such as the clearance angle and the linear velocity of the plow.After making 28 models for the plow,the best model of the plow was selected based on the maximum force applied to the machine in the X direction.Finally,the results of this study showed that the best plow performance is for a model with the clearance angle of zero and the linear velocity of 9 mm/min,and the maximum force applied to this model is equal to 39,000 kN in the X direction.

Optimized Design for the Plow of a Submarine Plowing Trencher

The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the towing force of a vessel. A multi-objective genetic algorithm based on analytical models of the plow surface has been examined and applied in efforts to obtain optimal design of the plow. For a specific soil condition, the draft force and moldboard surface area which are the key parameters in the working process of the plow are optimized by finding the corresponding optimal values of the plow blade penetration angle and two surface angles of the main cutting blade of the plow. Parameters such as the moldboard side angle of deviation, moldboard lift angle, angular variation of the tangent line, and the spanning length are also analyzed with respect to the force of the moldboard surface along soil flow direction. Results show that the optimized plow has an improved plow performance. The draft forces of the main cutting blade and the moldboard are 10.6% and 7%, respectively, less than the original design. The standard deviation of Gaussian curvature of moldboard is lowered by 64.5%, which implies that the smoothness of the optimized moldboard surface is much greater than the original.

Soil remediation of degraded coastal saline wetlands by irrigation with paper mill effluent and plowing

Combined with anti-waterlogging ditches, irrigation with treated paper mill effluent （TPME） and plowing were applied in this study to investigate the effects of remediation of degraded coastal sa- line-alkaline wetlands. Three treatments were employed, viz., control （CK）, irrigated with 10 cm depth of TPME （I）, and plowing to 20 cm deep before irrigating 10 cm depth ofTPME （IP）. Results show that both I-treatment and IP-treatment could improve soil structure by decreasing bulk density by 5% and 8%. Irrigation with TPME containing low salinity stimulated salts leaching instead of accumulating. With anti-waterlogging ditches, salts were drained out of soil. Irrigation with 10 cm depth of TPME lowered total soluble salts in soil and sodium adsorption ration by 33% and 8%, respective!y, but there was no significant difference compared with CK, indicating that this irrigation rate was not heavy enough to remarkably reduce so!l salinity and sodicity, Thus, in-i： gation rate should be enhanced in order to reach better effects of desalinization and desodication. Irrigation with TPME significantly increased soil organic matter, alkali-hydrolyzable nitrogen and available phosphorus due to the abundant organic matter in TPME. Plowing increased soil air circulation, so as to enhance mineralization of organic matter and lead to the loss of organic matter; however, plowing significantly improvedsoil alkali-hydrolyzable nitrogen and available phosphorus. Improvements of physicochemical properties in I-treatment and IP-treatment both boosted soil microbial population and activity. Microbial biomass carbon increased significantly by 327% （I-treatment） and 451% （IP-treatment）, while soil respiration increased significantly by 316% （I-treatment） and 386% （IP-treatment）. Urease and dehydrogenase activities in both I-treatment and IP-treatment were significantly higher than that in CK. Phosphatase in IP-treatment was significantly higher than that in CK. Compared to I-treatment, IP-treatment improved all of the soil properties except for soil organic matter. The key to remediation of degraded sa- line-alkaline wetlands is to decrease soil salinity and sodicity; thus, irri- gation plus plowing could be an ideal method of soil remediation.

Plowshares Wear Investigation of the Plows Working in Mountainous Conditions Using Statistical Probabilistic Modeling

A general technique for modeling of the wear of machine parts using the theory of probability and mathematical statistics is developed,which is implemented through the example of plows of agricultural plows.Regularities of their wear during working under mountainous conditions are established,an adequate probabilistic-statistic mathematical model is obtained,general characteristics of the distribution of wear are determined using statistical moments and their most common(modal)values are determined which allow to substantiate the method of restoring worn parts for the purpose of increasing their life.This technique can also be utilized to study the regularity of wear of parts of other machines.

Plowing Ahead

ALTHOUGH Zhao Zijian＇s business card shows his office is in Beijing, he spends half the year on business trips to Africa. Zhao, who hails from central ChinEs Henan Province. has been in the agricultural and construction machinery business for decades, and is now the general manager of China- Africa Machinery Corp. （CAMACO）. He is involved in agricultural and construction machinery investment and trade in Africa.

Two material removal modes in chemical mechanical polishing:mechanical plowing vs.chemical bonding

With the rapid development of semiconductors,the number of materials needed to be polished sharply increases.The material properties vary significantly,posing challenges to chemical mechanical polishing(CMP).Accordingly,the study aimed to classify the material removal mechanism.Based on the CMP and atomic force microscopy results,the six representative metals can be preliminarily classified into two groups,presumably due to different material removal modes.From the tribology perspective,the first group of Cu,Co,and Ni may mainly rely on the mechanical plowing effect.After adding H_(2)O_(2),corrosion can be first enhanced and then suppressed,affecting the surface mechanical strength.Consequently,the material removal rate(MRR)and the surface roughness increase and decrease.By comparison,the second group of Ta,Ru,and Ti may primarily depend on the chemical bonding effect.Adding H_(2)O_(2)can promote oxidation,increasing interfacial chemical bonds.Therefore,the MRR increases,and the surface roughness decreases and levels off.In addition,CMP can be regulated by tuning the synergistic effect of oxidation,complexation,and dissolution for mechanical plowing,while tuning the synergistic effect of oxidation and ionic strength for chemical bonding.The findings provide mechanistic insight into the material removal mechanism in CMP.

Detection of the farmland plow areas using RGB-D images with an improved YOLOv5 model

Recognition of the boundaries of farmland plow areas has an important guiding role in the operation of intelligent agricultural equipment.To precisely recognize these boundaries,a detection method for unmanned tractor plow areas based on RGB-Depth(RGB-D)cameras was proposed,and the feasibility of the detection method was analyzed.This method applied advanced computer vision technology to the field of agricultural automation.Adopting and improving the YOLOv5-seg object segmentation algorithm,first,the Convolutional Block Attention Module(CBAM)was integrated into Concentrated-Comprehensive Convolution Block(C3)to form C3CBAM,thereby enhancing the ability of the network to extract features from plow areas.The GhostConv module was also utilized to reduce parameter and computational complexity.Second,using the depth image information provided by the RGB-D camera combined with the results recognized by the YOLOv5-seg model,the mask image was processed to extract contour boundaries,align the contours with the depth map,and obtain the boundary distance information of the plowed area.Last,based on farmland information,the calculated average boundary distance was corrected,further improving the accuracy of the distance measurements.The experiment results showed that the YOLOv5-seg object segmentation algorithm achieved a recognition accuracy of 99%for plowed areas and that the ranging accuracy improved with decreasing detection distance.The ranging error at 5.5 m was approximately 0.056 m,and the average detection time per frame is 29 ms,which can meet the real-time operational requirements.The results of this study can provide precise guarantees for the autonomous operation of unmanned plowing units.

电动拖拉机犁耕机组阻力自适应作业控制研究

犁耕质量和效率对粮食高产至关重要,而以往基于悬挂高度调整以适应阻力变化来控制犁耕机组耕作效率存在耕深不均匀的问题。为此,以重心可调电动拖拉机犁耕机组为对象,提出了调定耕深下考虑速度和滑转率的阻力自适应作业控制方法。首先,建立了机组动力学模型并分析了阻力变化下机组的动态特性;然后,采用模糊神经网络控制算法调节驱动电机转矩和电池组位移,使牵引附着性能自动适应阻力变化,以实现速度和滑转率的联合控制;最后,进行了实车测试平台搭建和犁耕试验。结果表明:耕速最大偏差仅为0.48 km/h,相比于控制前滑转率降低了21.42%,牵引效率提高了7.76%。在恒定耕深下机组作业稳定性和效率得以提高,为电动拖拉机的自动化和智能化精准作业提供了技术支持。

Multiscale study of the dynamic friction coefficient due to asperity plowing

A macroscopically nominal flat surface is rough at the nanoscale level and consists of nanoasperities.Therefore,the frictional properties of the macroscale-level rough surface are determined by the mechanical behaviors of nanoasperity contact pairs under shear.In this work,we first used molecular dynamics simulations to study the non-adhesive shear between single contact pairs.Subsequently,to estimate the friction coefficient of rough surfaces,we implemented the frictional behavior of a single contact pair into a Greenwood-Williamson-type statistical model.By employing the present multiscale approach,we used the size,rate,and orientation effects,which originated from nanoscale dislocation plasticity,to determine the dependence of the macroscale friction coefficient on system parameters,such as the surface roughness,separation,loading velocity,and direction.Our model predicts an unconventional dependence of the friction coefficient on the normal contact load,which has been observed in nanoscale frictional tests.Therefore,this model represents one step toward understanding some of the relevant macroscopic phenomena of surface friction at the nanoscale level.

Application of adaptive neuro-fuzzy inference system to predict draft and energy requirements of a disk plow

The energy and draft requirements of a disk plow have been recognized as essential factors when attempting to correctly match it with tractor power.This study examines the possible of using an adaptive neuro-fuzzy inference system(ANFIS)approach and its performance compared to a multiple linear regression(MLR)model to determine the energy and draft requirements of a disk plow.A total of 133 data patterns were obtained by conducting experiments in the field and from the literature.Of these 133 data points,121 were arbitrarily selected and used for training,and the remaining 12 were used for testing the models.The input variables were plowing depth,plowing speed,soil texture index,initial soil moisture content,initial soil bulk density,disk diameter,disk angle,and disk tilt angle,and output variable was draft of the disk plow.Four membership functions were used with ANFIS:a triangular membership function,generalized bell-shaped membership function,trapezoidal membership function,and Gaussian curve membership function.An evaluation of the outcomes of the ANFIS and MLR modeling shows that the triangular membership function performed better than the other functions.When the ANFIS model draft predictions were compared to the measured values,the average relative error was-1.97%.A comparison of the ANFIS model with other approaches showed that the energy and draft requirements of the disk plow could be estimated with satisfactory accuracy.

Effects of autumn plowing on the movement and correlation of moisture,heat and nitrate nitrogen in seasonal freeze-thaw soil

A two-year experiment was established in northern Xinjiang to investigate the effects of autumn plowing methods on nitrate nitrogen accumulation,spring-sown soil conditions and cotton emergence rate,and to explore the response relationship between soil water,heat and nitrate nitrogen.The experiment included five autumn plowing treatments,namely,plough tillage(FG),no-tillage(MG),ridge and furrow alternation(LG),plough tillage with straw mulch(FJ)and plough tillage with activated charcoal mulch(FH).The results showed that both FH and FJ treatments were beneficial to promote the nitrate-nitrogen accumulation in topsoil,while FG,MG and LG treatments aggravated the nitrate nitrogen leaching in topsoil.During the freezing period,FH and FJ treatments were beneficial to reduce soil heat loss and facilitate the coordinated upward migration of soil water and nitrate nitrogen.In the thawing period,FH and FJ treatments favored suppressing the synergistic downward transport of soil water and nitrate-nitrogen and motivated the synergistic upward migration of heat and nitrate nitrogen in deep soil.Binary regression analysis suggested that the interaction between water,heat and nitrate nitrogen under FH and FJ treatments showed a highly significant correlation.FH and FJ treatments showed obvious advantages in regulating soil conditions and optimizing soil water,heat and nitrate nitrogen co-transport mechanism.During the spring sowing period,the FH and FJ treatments increased the average soil temperature by 0.99℃and 1.29℃,and the average soil moisture content by 6.01%and 8.70%,and the average soil nitrate content by 10.20 mg/kg and 10.47 mg/kg,in the 0-25 cm soil layer,respectively.FH and FJ treatments significantly grew the emergence rate of cotton,which can be used as the main autumn tillage strategies in arid areas of northern Xinjiang.

平行犁组翻扣与旋耕组合式油菜种床制备装置研究

针对长江中下游稻-油轮作区土壤黏重板结、秸秆量大,油菜直播机采用普通旋耕时易导致种床耕层浅、秸秆埋覆率低,现有犁旋一体机作业时纵向尺寸大的问题,结合油菜直播农艺要求和合理耕层构建需求,设计了一种平行扣垡犁组,提出了一种“圆盘犁刀切茬-压茬,平行犁组翻扣埋茬,旋耕刀辊碎土-匀土”的组合式耕整作业方案。采用直纹面法对扣垡犁的犁体曲面进行设计,构建了犁体曲面解析参数方程,建立了基于离散元方法的耕作部件-土壤-秸秆互作仿真模型,应用EDEM软件开展了二次正交旋转试验,分析了扣垡犁扣垡性能。仿真结果表明:当偏转角θ取12°、元线角差值Δθ取11°时,犁体扣垡效果最优。田间试验结果表明:当耕深为230 mm、作业速度为5.15 km/h时,扣垡犁平均扣垡率为91.3%,有较好埋茬效果;平行扣垡犁组在高茬秸秆工况下有较好的通过性,秸秆平均埋覆率达到82.5%,平均耕深达到218.6 mm,耕深稳定性系数达到90.2%。田间对比试验结果表明:在水稻收获后平均留茬高度为513 mm的工况下,平行犁组翻扣与旋耕组合式油菜种床制备装置平均耕深达229.7 mm,秸秆埋覆率为87.5%,碎土率为89.7%,厢面平整度为31.8 mm,相比于普通旋耕机作业效果,平均耕深增大90.9 mm,秸秆埋覆率和碎土率分别提高7.2个百分点和6.5个百分点,作业质量满足油菜播种要求,符合油菜“深翻埋茬,上松下紧”的种床合理耕层构建要求。

1LF-5型液压翻转犁的设计与试验

为推动玉米秸秆还田保护性耕作农艺的发展,设计了一种集土壤耕作技术、玉米秸秆还田技术于一体的1LF-5型液压翻转犁,一次作业既翻转了土层、松碎了土壤,又可将土壤表层的玉米秸秆与作物残茬翻入土层下,形成隔层进行还田;同时,犁体受到突发外力冲击时,安全装置自动生效,使犁柱绕固定轴栓旋转,从而保护犁体与犁柱的安全。田间试验表明:1LF-5型液压翻转犁的平均耕作深度稳定为33.45cm,平整度为20mm,变异系数在3.166%~3.535%之间;在第1工况下,翻转犁的耕宽平均值为220.75cm,耕宽的变异系数范围为1.21%~1.71%;在第2工况下,翻转犁的耕宽平均值170.1cm,耕作宽度的变异系数范围为1.26%~1.68%;植被覆盖率平均值为89.97%,土垡破碎率为72.27%。机具满足国家标准GB/T14225对于耕作质量的各项要求,也满足翻耕农艺要求。

基于LS-DYNA的铧式犁结构优化设计及性能分析

基于LS-DYNA法建立犁体与土壤的耦合接触有限元模型,讨论不同犁体导曲线、铧刃角、安装角、端点角、耕作速度对耕作过程翻垡效果和犁体应力影响,并进行试验验证。结果表明:椭圆曲面比抛物线曲面耕作时阻力更小、土壤翻垡效果更好,阻力降低5.6%,翻垡距离提升14.8%;对犁体前进速度、铧刃角、安装角、端点角进行单因素分析,发现翻垡距离随着速度增加而增加,而随着铧刃角、安装角、端点角呈现出先增大后减小的趋势。因此,通过选取合适的速度与结构参数可以提升铧式犁的翻垡性能,减低犁体阻力。

从清宫内务府汉文奏销档看织染局种种

文章基于中国第一历史档案馆藏内务府汉文奏销档中关于织染局的七份档案,通过梳理乾隆和嘉庆年间内织染局设置及所辖人、财、物变更等重要事项,分析了清朝中期织染局的沿革历史、人员构成和分工、所用物料、织造品类和使用去向等种种问题,阐明了织染局作为清代官营织造机构之一的特殊性质和使命,以及与江南三织造的联系和区别。织染局作为清代唯一一处位于京内的官营织造机构,其用丝主要来自江南三织造的供应,在匠役的来源上也与江南地区有着密切联系。由于地理条件及生产规模所限,织染局所产丝织原料质量、生产规模和产品类别均不能与三织造相比。但是作为随传随办的织造机构,织染局能够灵活应变,满足上用和内用的临时需求,因此在清代官营织造机构中具有特殊地位。而且,自乾隆十七年(公元1752年)织染局迁入万寿山演化为耕织图后,不仅通过精简人员和技艺优化来扩大生产品类和提高产品质量,更与皇帝倡导农桑的政策紧密结合,逐渐形成兼具实际生产意义和政策示范性的场所,同时也满足了皇帝对江南田园生活的向往,成为承载官营生产织造和皇帝人文思想的理想机构。

天水市旱作区春玉米—冬油菜秸秆带膜翻压还田栽培模式研究

为解决区域内春玉米—冬油菜一膜两用技术中秸秆利用不合理、土壤有机质含量低、有机肥投入不足、化肥施用不合理、土壤水分利用不足、肥料利用率较低等一系列问题,在天水市旱作区开展了春玉米—冬油菜秸秆带膜翻压还田栽培模式研究,以期为区域内化肥减施、地力提升和农业可持续发展提供依据。结果表明,秸秆粉碎带膜翻压还田可以提高玉米籽粒产量7.96%、冬油菜籽粒产量9.91%,增加0~20 cm土壤有机质、全磷、有效磷含量(分别增加2.53 g/kg、0.08 g/kg、10.93 mg/kg),缓冲土壤pH值,影响土壤速效钾、硝态氮和铵态氮水平。

西南喀斯特地貌区采煤沉陷对稻田的影响研究

为了研究分析采煤沉陷对稻田造成的影响,本文对比分析了采煤沉陷区内正常与非常稻田的土壤物理特性、犁底层入渗参数、水稻生长需水量以及生物和产量等因素。研究结果表明:在西南山地喀斯特地貌区,(1)采煤沉陷对稻田土壤的容重、孔隙度、机械组成影响不大,但影响土壤含水率较明显;(2)采煤沉陷导致稻田犁底层不同损坏,土壤入渗系数超过正常稻田犁底层土壤入渗系数10倍左右;(3)每公顷非正常稻田生长需水量比正常稻田多26.7 m^(3)水量;(4)每公顷正常稻田的产量和秸秆干重比非正常稻田分别多出3100 kg和1200 kg。而正常稻田的单株稻根干重比非正常稻田多1.74 g。总之,在西南山地喀斯特地貌区采煤沉陷已严重影响了稻田的正常生产,特别是稻田犁底层方面的损坏,这对于区域进行稻田生态复垦和社会协调稳定都具有理论与实践价值。

基于犁式卸料器卸煤的筒仓应急排料系统

针对早期建成的筒仓没有惰化保护系统,经常出现由于筒仓使用管理不当而导致储煤自燃且难以处置的问题,提出了基于犁式卸料器卸煤的筒仓储煤自燃应急排料系统的处置方案。该方案实施后取得了良好的效果,可为同类筒仓提供参考。同时,提出了即使新建电厂设计了筒仓惰化保护系统,也应在输煤系统的适当部位设计犁式卸料器或其他适宜的应急排料系统的建议,保障筒仓安全。