变量施肥液压系统设计与试验研究

通过分析国内外变量施肥技术的研究状况,概述了水稻变量施肥机总体设计和结构特点,对驱动撒肥盘变速的液压驱动系统进行设计,确定了液压组件的型号、参数并进行了转矩与功率校核计算,对决定施肥量变化的肥料流速与落肥口长度之间的函数关系进行试验研究,确定了线性函数方程,用于变量施肥作业.通过施肥试验和实际应用,表明自走式水稻变量施肥机整机结构设计、液压变量施肥系统设计和电磁式排肥活门结构适合整机在水田里自主行走,在水稻生长期实施变量施肥工作要求.     

液压变量施肥控制系统设计与试验

为解决现有水田撒肥机械存在肥量调节控制技术落后、不能适应变量作业工作要求等问题,设计了一种变量撒肥控制系统.通过分析国内外变量施肥技术研究情况,概述了变量撒肥机总体结构和工作原理,研究了控制内容和控制策略,确定了以AT89C51单片机作为主控制核心元件的计算机控制系统,进行软硬件设计和系统集成.通过场地和田间撒肥试验表明,撒肥机作业效率达到6 hm2/h,施肥量偏差小于5％,排肥量稳定性变异系数仅为6.2％,撒肥机工作性能和控制系统设计满足水田变量撒肥工作要求.     

叶菜设施种植自动排肥装置设计与实现

针对叶菜设施种植过程中施肥控制自动化程度低,劳动强度大和施肥效率低的难题,综合运用机电控制、嵌入式软硬件开发和系统集成系统等先进技术,提出一种能够即时便捷控制施肥量的自动排肥方法,研制开发了一种结构轻便微型施肥机,对于降低劳动强度、提高施肥效率等有重要意义。     

2BQMS-2A型免耕坐水播种施肥机设计研究

一、280MS-2A型免耕坐水播种施肥机设计方案 1.2BQMS-2A型免耕坐水播种施肥机结构 如图1所示,该机由风机、传动系统、梁架、破茬器、施肥开沟器、播种开沟器、排肥器、排种器、地轮、镇压轮、覆土器、水箱、水箱架、供水系统等组成.风机安装在拖拉机的前保险杠上,通过三角带与柴油机输出的双联皮带轮相连.     

整地施肥铺膜机施肥装置的设计

设计开发一种能同时适应粉肥和粒肥及其混合物的施肥装置,该装置采用的排肥星轮,能使施肥均匀且施肥量与手扶拖拉机的作业速度同步,通过机构调节,还可实现按需精确施肥;通过田间试验和测试,该施肥装置能满足农艺所需要求.     

基于离散元法的双变量施肥机排肥装置分析与试验

为提高基于处方图技术的双变量施肥机的施肥精度,改善变量施肥系统的稳定性,提高肥料的利用率,建立了外槽轮式双变量施肥机离散元模型,运用离散单元法对不同外槽轮排肥器排肥过程进行性能模拟仿真分析,研究不同排肥器结构对排肥稳定性的影响,并通过台架试验验证仿真实验的准确性。结果表明:改进后的外槽轮c排肥稳定性最好,变异系数最小,相比于外槽轮a降低了36.59%,且验证试验与仿真实验误差较小,具有相同变化趋势。该研究为槽轮排肥器及其关键部件的优化设计提供了参考。     

智能施肥机自动控制系统的分析

我国目前的农业施肥技术虽然取得了一定的进展,但是创新性的研究还有待加强.文章分析了智能施肥机自动控制系统的工作内容、工作原理和主要功能,同时对自动控制技术的总体设计方案、软件技术、通讯技术和相关技术的设计情况进行了研究分析.     

智能施肥机自动控制系统的分析

现阶段,中国在农业施肥技术研究上还存在很多不足之处,所使用的精密施肥装置多来自国外,价格十分昂贵。对智能施肥机控制系统的设计情况进行总结,并从相关技术的合理应用、智能灌溉施肥控制技术的分析、总体设计方案、通讯设计四方面,论述了智能施肥机自动控制系统的主要分析内容。     

墨江县玉米有机肥替代化肥减量试验研究

为考察玉米在同等配方下减少氮磷钾肥的施肥量,增加相应的有机肥后的节肥效果,开展了玉米有机肥替代化肥减量田间试验。结果表明,在同等配方下采用缓释配方肥、缓释配方肥减20%+有机肥、配方肥减20%+有机肥的施肥模式可实现稳肥增产增收、节肥增产增收,为大面积推广玉米化肥减量增效施肥技术提供依据。     

水稻机插秧同步侧深施肥机具性能试验初报

针对本市常用的洋马2ZGQ-6(VP6D)、YR80DF乘坐式高速插秧机配洋马2FC-6侧深施肥装置;久保田2ZGQ-8D1乘坐式高速插秧机配配久保田2FH-1.8A(FSPV6)侧深施肥机开展机械性能试验,对侧深施肥机的作业效率、可靠性、作业质量、排肥均匀度等进行测试。试验表明,水稻机插秧同步侧深施肥机具性能稳定,可靠。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.