光学和电子显微镜的直边衍射和象质评价

本文在部分相干条件下,研究了光学和电子显微镜的直边衍射和象质的评价及定量测试方法。描述了相应的实验装置,物理模型和数值计算结果。这些结果为显微(或微缩)系统的设计评价和装校测试提供了新的途径。     

数控车床和铣床的扩展和设计

本文主要论述了车床和铣床的数控化扩展和设计中的改变系统结构由封闭式想pc机+控制器的开放式转变,以及铣床的注意事项.通过此种方式可以大大提高其适应现代化生产的需要,满足当今网络化、敏捷化制造的要求.     

振动和冲击测量的校准和标准

本文叙述了如何建立标准加速度计体系,例如工作传感器可以追溯到基准和基本单位。概观当今振动和冲击测量用加速度计的绝对校准法和比较校准法,可以通过下列方法来精确地实现。     

免疫电泳和双向电泳技术的发展和应用

1937年电泳技术的鼻祖Tiselius教授建立了最早期的移界电泳用于蛋白质分离与鉴定,开创了现代电泳技术的新纪元.随着各种电泳新技术的发展,电泳和其他技术的结合,以及各种先进的电泳仪的不断出现,使得许多与蛋白质结构和功能有关的研究得以飞速发展.本文主要就近年来备受关注的免疫电泳和双向电泳技术的发展和应用做一评述.     

我国包装和食品机械行业现状和科技进步展望

改革开放以来,随着我国国民经济的迅速发展。我国的包装和食品机械行业取得了世人瞩目的发展。农、林、牧、副、渔业资源的深度加工,包装工业和食品工业的广阔市场,人民生活水平的不断提高,使包装和食品机械行业成为直接为提高人民生活质量服务,为包装工业和食品工业服务,为广大农业服务的新兴行业。产品品种和数量不断增加,产品质量和技术水平不断提高。基本上满足了我国包装工业和食品工业及大农业发展的需求。并有部分产品走出国门为国家创汇。     

液压泵和马达安装法兰和轴伸的尺寸系列和标记(一)

本标准规定了液压泵和马达的菱形、方形安装法兰和轴伸的尺寸系列和标记,作为制订各类液压泵和马达采用该型式的安装法兰和轴伸的依据。有特殊要求的航空用液压泵和马达的安装连接尺寸,不属此范围。本标准参考了国际标准ISO3019/2《液压泵和马达安装法兰和轴伸尺寸系列和标记,第二部分:2孔和4孔法兰和轴伸——米制》。 1、菱形、方形安装法兰 1.1 菱形安装法兰,分为短止口和长止口二种,设计时根据具体情况采用。其结构和尺寸系列按图1和表1规定。     

我国包装和食品机械行业现状和科技进步展望

改革开放以来,随着我国国民经济的迅速发展。我国的包装和食品机械行业取得了世人瞩目的发展。农、林、牧、副、渔业资源的深度加工,包装工业和食品工业的广阔市场,人民生活水平的不断提高,使包装和食品机械行业成为直接为提高人民生活质量服务,为包装工业和食品工业服务,为广大农业服务的新兴行业。产品品种和数量不断增     

碳酸根和碳酸氢根测定方法和自动测定仪

油田水中含有大量的碳酸根和碳酸氢根 ,介绍采用双电极法测定的原理和方法 ,并研制基于该法的自动测定系统。测试系统以单片机为核心进行控制和信号处理 ,放大电路实现高阻抗匹配和信号放大 ,温度补偿电路实现温度的自补偿。系统具有性能可靠、测量速度快、测量范围宽、可长时间连续使用和在线测试的特点。     

责任感和建设性

今年5月底，我参加了在沈阳和大连召开的“百万吨乙烯装置配套重大装备技术交流会”，此次技术交流会是为落实国家发改委关于积极推进百万吨级乙烯建设工程装备国产化的要求，进一步做好国产化技术论证工作，由机械工业联合会和中石油、中石化共同研究召开的。国家主管部门、制造商和应用行业客户三方专家会聚一堂，会议上中石化、中石油有关部门和专家介绍了百万吨乙烯装置的工艺和技术要求，     

互感分压器和互感分流器的误差和实际应用

本文介绍互感分压器和分流器的结构、误差和实际应用。二者的结构和误差计算公式相同，因而有的仪器可分别作为分压器和分流器使有。实际应用主要有：检定电流和电压互感器，检定电阻分流器和分压器，进行阻抗和导纳比较以及检定互感器校验仪整检装置和互感器校验仪的同相盘。文中对检定结果的误差计算作了分析和推导。     

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.     

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....     

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。     

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.