谈编制习题

编制习题是数学教师的一项基本功。数学教师掌握编制习题的方法有助于深入理解教材中有关例题习题的编排,掌握题目间的联系,更好地发挥例题习题的作用。可以根据学生实际和教学进程的需要改编教材中的习题或编制新     

热弹性马氏体相变材料单晶体的细观力学统一本构模型

基于马氏体相变的晶体学理论和Hill Rice内变量本构理论 ,建立了热弹性马氏体相变材料单晶体的细观力学统一本构模型并对它进行了详细的讨论 .该本构模型能描述在复杂热力学加载条件下 ,热弹性马氏体相变材料微结构正向相变、反向相变以及重取向过程在单晶体中所表现出来的宏观本构特性 .理论预测与实验结果符合很好 .     

弹性地基上reissner板的基本解

1 引言弹性地基厚板在工程上有着广泛的应用,如水工建筑物的底板,机场面板等.在厚板的力学分析中,由于抛弃了Krichhoff 假设,使得其控制方程和边界条件十分复杂.至今,弹性地基厚板只有一对边简支、四边自由的矩形板得到过精确解,而对于复杂边界条件或其它不规则形状的厚板,要求得既满足控制方程又满足边界条件的解析解是非常困难的.另一方面,边界元法已展示了它强大的生命力和优越性,在各个领域中得到了     

层状介质中声无损检测的模拟研究

本文针对层状复合结构的实际声无损检测情况,模拟研究了声波垂直和斜入射两种情况下回波响应与层状结构特性变化的定量或定性关系,从而不仅比较明确地分析了实际检测中出现的多种现象,而且为实际检测的条件选择提供了依据。首先,在前人的弹性波理论基础上,简明推出了两个更为适用于计算机模拟的递推公式。其次开发了传输树的概念,使复杂的层状介质中的波传播过程变得了然。最后是系统的模拟研究,着重于粘接层的缺陷和各层中的高衰减这两大实际因素。     

Solving viscoelastic problems with cyclic symmetry via a precise algorithm and EFGM

The paper combines a self-adaptive precise algorithm in the time domain with Meshless Element Free Galerkin Method (EFGM) for solving viscoelastic problems with rotationally periodic symmetry. By expanding variables at a discretized time interval, the variations of variables can be described more precisely, and iteration is not required for non-linear cases. A space-time domain coupled problem with initial and boundary values can be converted into a series of linear recursive boundary value problems, which are solved by a group theory based on EFGM. It has been proved that the coefficient matrix of the global EFG equation for a rotationally periodic system is block-circulant so long as a kind of symmetry-adapted reference coordinate system is adopted, and then a partitioning algorithm for facilitating parallel processing was proposed via a completely orthogonal group transformation. Therefore instead of solving the original system, only a series of independent small sub-problems need to be solved, leading to computational convenience and a higher computing efficiency. Numerical examples are given to illustrate the full advantages of the proposed algorithm. The project supported by the National Natural Science Foundation of China ((10421002, 10472019 and 10172024); NKBRSF (2005CB321704) and the Fund of Disciplines Leaders of Young and Middle Age Faculty in Colleges of Liaoning Province. The English text was polished by Yunming Chen.     

纵向泵浦Tm：YAG激光器的理论研究

用准三能级系统速率方程对纵向泵浦Ｔｍ：ＹＡＧ激光器的阈值，效率和激活介质最佳长度进行了计算和分析，讨论了温度对Ｔｍ：ＹＡＧ激光器输出特性的影响。     

量子光学相干层析扫描显微镜

迈克耳孙干涉仪在历史上曾被用于研究光速问题.光源发出的光被分成两路,在其中一路上安放样品.由于光程差与样品有关,当检测两束光重新相遇时的相干状态,即可导出样品的光学性质.几年前,在上述技术基础上发展起来的光学相干层析装置,已经成为人体器官三维结构成像的有力工具.在