工件以圆孔在心轴上定位误差的分析与计算

工件以圆孔在心轴上定位误差的分析与计算湘潭机电专科学校彭庚新若定位时孔与心轴（或定位销）固定单边接触，如图１所示，工件孔与水平放置的心轴在上母线接触；要求保证尺寸ｂ＋δｂ０及ａ０＿－δａ，其中尺寸图１定位误差分析示例ｂ＋δｂ０是由铣刀决定的，而尺寸ａ...     

高亮度红色Ca1—xAlxAs／Ga1—yAlyAs发光二极管研究

研制成功了Ｇａ１－ｘＡｌｘＡｓ／Ｇａ１－ｙＡｌｙＡｓ双异质结红色（６７０ｎｍ以光二级管。本项研究采用了具有独创的双层石墨相外延，并改进了电极制作技术，取得很好的结果。     

检验区域输瓶装置的改造与控制

根据生产规模的不同,链板式输瓶机的输送带列数也不等。但在通过检验区域时,输瓶装置必须让瓶子成单列运行,以确保产品的质量和检验效果。这就存在多列输送带要逐渐过渡成单列的问题,处理不好就会出现堵瓶现象,这是输瓶技术中的一个难点。既影响生产,又增加工人的劳动强度。 ９０年代初,我厂安装的一条啤酒包装生产流水线,在检验区域对输瓶装置作了以下技术处理（见图１）。区域入口端电机Ｄ１带动Ａ１、Ａ２、Ａ３和ａ１、ａ２、ａ３列输送带以正常速度运转;为保证瓶子的通过量,区域出口端电机Ｄ２带动Ｂ１、Ｂ２和ｂ１、ｂ２列…     

带内冷却槽的JET－CUT切断刀和切槽刀系统

带内冷却槽的ＪＥＴ－ＣＵＴ切断刀和切槽刀系统现有各种冷却方法存在的一个根本问题，就是冷却液不能到达切削区（图１ａ），因此不能从根本上改善从切削区排热的状况。图１（ａ）从上面浇注冷却液示意图（ｂ）用ＪＥＴ－ＣＵＴ方法注入冷却液（１．被加工毛坯２．冷却液...     

非线性晶体硫硒镓银的生长及光学特性的研究

硫硒镓银ＡｇＧａ（Ｓｅ１－ｘＳｘ）２晶体是优良的红外非线性材料。本文详细探索了硫硒的银的Ｉ型光参量相位匹配特性。利用常用的Ｎｄ：ＹＡＧλ＝１．０６μｍ光源泵浦，计算了ＡｇＧａ（Ｓｅ１－ｘＳｘ）２Ｉ型ＯＰＯ角度调谐曲线。通过改变晶体成份改变短波吸收边、折射率和双折射，来设计新型功能的混合晶体。利用布里奇曼方法生长ｘ＝０．２、０．５和０．７５硫硒镓银单晶体。生长的晶体添加有ＡｇＧａ（Ｓｅ１－ｘＳｘ）２     

单运放组成多限多态比较器

单运放组成多限多态比较器于志刚白明友１由单运放组成的双限双态比较器图１图１（ａ）所示为双限双态比较器；１（ｂ）为其电压传输特性曲线。由图１（ａ）可得：Ｖｐ＝Ｒ２Ｒ１＋Ｒ２ｖｉ；ＶＮ＝Ｒ３Ｒ４Ｒ５×Ｅ２Ｒ５（Ｒ４＋Ｒ３）－Ｅ１Ｒ４（Ｒ３＋Ｒ５）＋ｖｉＲ...     

类四杆五杆机构连杆曲线的变化规律

类四杆五杆机构连杆曲线的变化规律张旭滨（渤海铝业有限公司０６６０００）贲宏艳刘葆旗（燕山大学）１引言类四杆五杆机构就是把铰链四杆机构的某一个杆ａ截成两个杆，并用转动副相联，较短的一个杆称为调节杆ｅ，较长杆为ａ′，且ｅ／ａ′≤０．２５，ｅ和ａ′的传动...     

油气输送管的止裂韧性研究

通过楔子横向加载,用ＣＣＡ试样研究了油气输送管的止裂韧性。显然止裂韧性是一顶重要的材料参数。试验结果表明,止裂韧性Ｋａ与夏比冲击吸收能ＣＶＮ之间存在如下关系：Ｋａ＝０．０１０３ＣＶＮ＾２＋１．２７０３ＣＶＮ＋１４．１４６。裂纹扩展长度取决于应力场强度因子的变化：Ｋ０－Ｋａ＝２５７１．９ａ－１０４．１４。     

同位素稀释质谱法对年青玄武岩K—Ar年龄的测定

用同位素稀释质谱法在ＲＧＡ－１０质谱计和析Ａｒ仪联合系统中，分析测定了一批年青玄武岩样吕的常规Ｋ－Ａｒ年龄。绝大多数杂品的年龄值在０．１－０．７Ｍａ之间，只有少几个样品的值在１－２Ｍａ之间，所测年龄都在第四纪范围内。     

热喷涂镍基高温润滑涂层的研究

采用粉末火焰喷涂技术以１Ｃｒ１８Ｎｉ９Ｔｉ为底材,以ＣａＦ２／ＢａＦ２为润滑剂,采用Ｎｉ６０Ａ自熔粉末为基体制备了镍基高温润滑涂层,并对该涂层的摩擦学性能进行了评价。     

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.