京瓷推出加工效率与寿命达原来2倍的加工工具

日本京瓷公司正在开发加工效率与寿命提高到原来产品2倍左右的钢加工工具“CA5515”与“CA5525”，定于2005年1月下旬上市。面向高可靠加工的CA5515重视耐缺损性，面向长寿命加工的CA5525重视耐摩损性，均可以降低加工时的总成本。     

新型线切割放电加工机——三菱NA系列

三菱公司生产的NA系列机床是针对高精度加工的领域而开发，从机床结构、加工电源、控制系统、驱动系统等方面都作了全面更新，并同时考虑加工精度、速度、装夹性以及节能性。     

涡轮叶片经济性研磨加工方略

在加工制造涡轮叶片时要对弯曲面进行内加工和外加工，还有些涡轮叶片部位接近性差，而且涡轮叶片材料也难于切削，     

涡轮叶片经济性研磨加工方略

在加工制造涡轮叶片时要对弯曲而进行内加工和外加工，还有此涡轮叶片部位接近性差，而且涡轮叶片材料也难于切削。     

五轴数控加工中多刀加工自由曲面的刀具选择

针对自由曲面的五轴数控加工，提出一种新的刀具选择方法，此算法可以自动地选择出最优刀具组合，每个刀具对应一个或多个特定的加工区域。多刀具组合的加工方法既可以保证加工曲面的精确性，又可以实现大刀具的高效加工。此外，还提出了种五轴教控加工时间的近似算法，通过对比用刀具组合加工时间和单个刀具加工时间，从而证明了该方法的有效性。     

系统柔度的不均匀性对加工精度的影响

本文从理论上证明了车削加工工艺系统柔度的不均匀性对加工精度的影响规律，提出了一些提高加工精度的措施和建议。     

汽车细长传动轴类零件的加工工艺

本文针对汽车细长传动轴类零件的加工，讨论了此类零件在加工工艺方案、工艺方案经济技术性、工装配置、刀具选择、设备选型及加工生产线布置等方面的共性问题，并在一个实际零件的加工中得到了应用，取得了良好的效果。     

数控加工与传统机加工工艺比较

在科学技术突飞猛进的发展背景下，加工工艺也发生了极大的改变。由传统机加工发展为数控加工标志着技术的进步及完善。本课题笔者从多方面对数控加工与传统机加工工艺进行了比较，希望以此为加工工艺的完善及发展提供一些具有价值性的参考依据。     

高效、节能、短流程加工技术在有色金属加工中的应用

由于资源具有不可再生性和有限性，开发和推广高效，节能，短流程加工技术，实施可持续性发展的资源战略是十分重要的。有色金属的连铸连轧，连续铸轧是典型的高效，节能，短流程加工技术，半固态金属成形技术，复合材料加工技术等都能提高材料的利用率，达到节能，节材的目的，制定相关的政策和建立我国有色金属绿色加工的评价标准能有效地促进高效，节能，短流程加工技术在有色金属加工中的应用。     

工程陶瓷材料加工技术现状

由于工程陶瓷具有极高的硬度，良好的耐磨性和耐磨蚀性以及脆性高等特点，成为难加工材料，特别是加工高精度，形状复杂的构件非常困难因此，陶瓷材料作为工程结构材料的大规模推广使用，在很大程度上取决于陶瓷零件加工技术的发展。本文综述了国内外陶瓷材料加工技术的研究现状。     

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...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

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.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

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.     

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...