用超几何函数证明全椭圆积分的一个替换公式

经构造两个邻次超几何函数的恒等式，可以证明用模数ｋ与ｋ１表示的第一，二两种全椭圆积分的一个替换公式。利用这个替换公式和高斯变换，能够很方便地处理圆电流所在平面上的磁场分布问题。     

EXTRACTED CONTROL APPROACH FOR CNC NON‐CIRCULAR TURNING

Non‐circular pistons are becoming increasingly popular in internal combustion engines as they facilitate the construction of a more efficient engine. However, at the moment, it is still a very expensive and time consuming procedure to cut non‐circular pistons, owing to practical problems which have yet to be overcome. This paper will examine these problems and highlight an Extracted Computer Numerical Control (ECNC) solution which can be used on existing Computer Numerical Controlled (CNC) Lathes. A high speed linear servo unit is presented as an extracted part of the system. Repetitive control is also discussed in the paper.     

Yield modeling of elliptical defect

Physical defects have always played an important role in integrated circuit (IC) yields, and the design sensitivity to these physical elements has continued to increase in today’s nanometer technologies. The modeling of defect outlines that exhibit a great variety of defect shapes is usually modeled as a circle, which causes the errors of critical area estimation. Since the outlines of 70% defects approximate to elliptical shapes, a novel yield model associated with elliptical outlines of defects is presented. This model is more general than the circular defects model as the latter is only an instance of the proposed model. Comparisons of the new and circular models in the experiment show that the new model can predict yield caused by real defects more accurately than what the circular model does, which is of significance for the prediction and improvement of the yield. Translated from Journal of Xidian University, 2006, 33(3): 433–437 [译自: 西安电子科技大学学报]     

皱纹长圆铜波导

微波通信所用的馈线,除要求其具有良好的电气性能外,还要求其可绕、大长度.皱纹长圆铜波导(以下简称长圆波导)不失为一种较好的馈线,为此介绍了此波导的特点、理论分析和设计方法,以及它与常用的椭圆波导、茧形波导之间的差异.此外,长圆波导的另一个用处是作为移动通信的漏泄波导,兼顾传输线和天线的作用.     

An improved method for magnetic identification and localization of cracks in conductors

A SQUID magnetometer can be used to measure the magnetic field produced by flaws in a two-dimensional, conducting plate carrying a current. Identification of the flaw-induced magnetic field is difficult because of the large magnetic field associated with the edges of the plate and the current in the leads that connect the plate to the power supply. We have developed a technique by which the wire and edge fields can be cancelled prior to mapping the magnetic field. In this technique, a similar unflawed conducting sheet is placed adjacent to the flawed plate, with a connection between the sheet and the plate at one edge, and with the opposite edges of the sheet and of the plate connected to the two conductors of a coaxial cable. Thus, an applied current will flow along one conductor of the cable, across the cancelling sheet, cross into the flawed plate, return along the plate, and then return to the power supply along the other conductor of the coaxial cable. As a result of this geometry, there is no magnetic field from the lead-in wires because they are coaxial, and the magnetic field due to the edges of the plate is cancelled by the opposing magnetic field of the edges in the adjacent sheet. The extent of cancellation is determined primarily by the separation between the plate and the cancelling sheet, by the thickness of the plate, and by macroscopic inhomogeneities in their electrical conductivities.     

矢量量化的几何方法

矢量量化是一种非常重要的数据压缩技术.其应用最多的聚类算法复杂度随着码率和维数的乘积指数增长.为了减小复杂度,本文给出几种适用于特定信源的几何矢量量化方法如适用于高斯信源的椭球矢量量化(EVQ),适用于拉普拉斯信源的棱锥矢量量化(PVQ).最后,针对几何分布不规则的一般信源,给出一般的几何矢量量化方法--标量矢量量化(SVQ).     

椭圆形钢管混凝土长柱偏压力学性能研究

利用有限元分析软件ABAQUS建立了椭圆形钢管混凝土长柱偏压力学性能分析的有限元模型,并对12个椭圆形钢管混凝土长柱的偏压试验结果与有限元模拟结果进行对比。结果表明:有限元计算与试验所得的荷载-挠度全过程曲线、承载力及破坏形态吻合较好。在此基础上对其受力过程中钢管及混凝土应力、应变分布情况进行分析,同时给出钢管与混凝土之间的相互作用,并对长细比、偏心距、材料强度、钢管壁厚等参数对长柱偏压极限承载力及荷载-柱中挠度曲线的影响进行比较。结果表明:椭圆形钢管混凝土长柱在H/2处发生侧向挠曲破坏,长细比、混凝土抗压强度、钢管壁厚及偏心距等参数对其力学性能影响显著,钢管屈服强度对其力学性能影响不明显。     

单层椭圆抛物面网壳自振特性分析及实用公式

系统分析了矢跨比、跨度、支座刚度和屋面荷载等因素对单层椭圆抛物面网壳自振特性的影响,并在对大量该网壳模型自振特性分析基础上,利用多元最小二乘法拟合出了单层椭圆抛物面网壳基本频率的计算公式,同时对该公式的精确度进行了验证。     

结构形式对椭圆扁管管内传热与流阻性能影响

利用数值模拟方法结合场协同理论,对直椭圆扁管、单向螺旋椭圆扁管和变向螺旋椭圆扁管管内传热与流动情况进行了数值模拟计算和理论分析,比较研究了不同的Re、Pr下,3种椭圆扁管的管内传热与流阻特性。结果表明,单向螺旋椭圆扁管和变向螺旋椭圆扁管与直椭圆扁管相比有很好的强化传热性能,而变向螺旋椭圆扁管要比单向螺旋椭圆扁管的强化传热性能更好。在管内流体具有高Pr及低Re的条件下,2种螺旋椭圆扁管的强化传热效果显著,可作为很好的强化传热元件应用于工程实际中。     

全新冷却方式双椭圆泵浦腔的实验研究

报导一种全新冷却方式的双椭圆泵浦腔，具有较高的泵浦效率和光学均匀性。１．０６μｍ调Ｑ脉冲输出能量总转换效率η＞０．７５％