A COMPARATIVE STUDY ON THEh－CONVERGENCE OF 4－NODE AND 8－NODE QUADRILATERAL ELEMENTS

ＤｕａｎＭｅｉ（段梅）；ＹｕｔａｋａＭｉｙａｍｏｔｏ（宫本裕）；ＺｈｏｕＢｅｎｋｕａｎ（周本宽）；ＣｈｅｎＤａｐｅｎｇ（陈大鹏）（ＲｅｃｅｉｖｅｄＭａｒｃｈ２，１９９５）ＡＣＯＭＰＡＲＡＴＩＶＥＳＴＵＤＹＯＮＴＨＥｈ－ＣＯＮＶＥＲＧＥＮＣＥＯＦ４－Ｎ...     

氮化硅/钽硅X射线光刻掩模研制及应用

经过三十多年的研发, 接近式X射线光刻技术已经非常成熟,其具有分辨率高、焦深大、工艺宽容度大、产量高等诸多优点.对于X射线掩模吸收体材料, 如果选择金, 只能采用电镀工艺, 而且金会污染硅基集成电路；而钽硅材料可以采用干法刻蚀工艺, 不会污染硅基集成电路, 是一种理想的X射线掩模吸收体材料.本文论述了氮化硅/钽硅X射线掩模制作工艺, 不同于常规工艺, 电子束光刻显影后, 以ZEP520电子束光刻胶作为阻挡层,SF₆/CHF₃作为反应气体, 电感耦合等离子体直接刻蚀钽硅薄膜.初步的实验结果证明了这种X射线掩模制作工艺是可行的.     

硅微机械FP腔器件机电特性模拟

介绍了一种硅微机械FP腔器件,该器件作为光学滤波器、光学衰减器等在光纤通信技术中具有广泛应用.采用化学气相沉积、刻蚀、金属蒸发等工艺对该器件进行加工，并利用湿法腐蚀释放使其形成悬空结构，悬空膜采用静电激励驱动.分析了器件的基本原理、工作范围、静电激励的阈值电压等特性，并指出了影响阈值电压大小的因素.     

人工机械瓣／血液耦合系统瞬态有限元分析

本文将人工机械心瓣／血液耦合系统作为研究对象，采用有限元法，分析了热解碳、钛合金钢、钴－铬合金钢及陶瓷四种材料机械瓣关闭状态下受突加阶梯压力荷载时的瞬态动力行为。结果表明，人工机械瓣态动力行为近乎刚性，寻致瓣叶上产生较高冲击压力，减小机械瓣的弹性模量，可以降低瓣／血液耦合系统的冲击压力。     

一些天然、合成及仿造宝石的显微拉曼光谱鉴别

本文主要测定部分天然宝石、合成宝石以及仿造宝石 ,以期建立云南宝玉石拉曼光谱数据库 ,进而为鉴别宝石的合成品、仿造品提供标准谱图     

俄国第一个物理学派——列别杰夫实验物理学派的形成与启示

俄国自彼得大帝采取开放政策以来,文化科学与教育事业虽得以发展,但最初以派留学生和聘请国外著名学者赴俄进行科学研究,担任科学院院士或以讲学的方式培养俄国的科技人才,进程比较缓慢,收效不是很大.到十月革命前,在物理学科领域中,仅出     

Thermal and mechanical characterizations of asubstrate-free focal plane array

We propose a substrate-free focal plane array (FPA) in this paper. The solid substrate is completely removed, and the microcantilevers extend from a supporting frame. Using finite element analysis, the thermal and mechanical characterizations of the substrate-free FPA are presented. Because of the large decrease in thermal conductance, the supporting frame is temperature dependent, which brings out a unique feature: the lower the thermal conductance of the supporting frame is, the higher the energy conversion efficiency in the substrate-free FPA will be. The results from the finite element analyses are consistent with our measurements: two types of substrate-free FPAs with pixel sizes of 200× 200 and 60× 60~μ m² are implemented in the proposed infrared detector. The noise equivalent temperature difference (NETD) values are experimentally measured to be 520 and 300~mK respectively. Further refinements are considered in various aspects, and the substrate-free FPA with a pixel size of 30× 30~μ m² has a potential of achieving an NETD value of 10~mK.     

成形过程数值模拟的非增量时一空算法*

本文针对计及几何、材料、接触摩擦等耦合作用的高度非线性的加工成形过程数值模拟和计算分析工作,建议了非增量时-空求解算法。本文的非增量算法,系在整个时间域和空间域上迭代求解,与常见的Newton-Raphson算法明显不同。本文所附算例,进一步说明了本算法的正确性和可行性。     

A penalty-hybrid finite element analysis of stokes flow

A type of penalty-hybrid variational principle is suggested for the analysis of Stokesian flow. On such a basis, a finite element model is formulated featuring, among others, a priori satisfaction of the deviatoric stress and hydrostatic pressure on linear momentum balance equations. Also in the present scheme the hydrostatic pressure is successfully eliminated at the element level, leaving only nodal velocities as solution unknowns. A series of 4-node and 8-node quadrilateral elements are derived and examined. Numerical examples demonstrating their characteristic behaviors are also included.The project Supported by National Natural Science Foundation of China