杆板结构系统的可靠性分析

提出一种可模拟飞行器翼面等薄壁结构的杆板结构系统的可靠性分析方法，导出在Ｍｉｓｅｓ屈服条件下平面应力元件的完全裕量方程。     

半质环的交换性条件

给出了Ｂａｅｒ半单纯环的两个交换性条件，并对其中心元进行了讨论，得到了两个结果。     

活性炭净水应用技术问题的探讨

本文综述了活性炭在给水处理中的几种应用方法，对应用中存在的问题进行了探讨．     

A novel method of structural shape optimization coupling BEM with an optimization method based on biological growth

Local stress peaks are the main reason for fatigue failure of structures, and therefore many researchers make every effort to search for effective methods of structural shape optimization. Mattheck and Burkhard (1990) have developed a method by simulating the self-optimization mechanism of biological growth, using FEM. BEM is a very effective method in which only the boundary is divided into elements, and particularly, accurate results at the boundary can be obtained. It is obvious that BEM is a more suitable analysis method for structural shape optimization than FEM. Coupling BEM of three-dimensional thermoelasticity problems with an optimization method based on biological growth, a novel method of structural shape optimization is successfully developed by the authors. Several examples are used to demonstrate that the method is successful and efficient.     

Comments on “Robust tracking control for rigid roboticmanipulators”

In the original paper by M. Zhihong and M. Palaniswami (ibid., vol.39, p.154-9, 1994), a robust tracking control using a nominal feedback controller and a variable structure compensator for a rigid robotic manipulator with uncertain dynamics was presented. It is assumed that the model uncertainty is bounded. The author claims that this assumption is not necessarily correct and that the results obtained are therefore untenable     

基于碰撞算法的冲裁件优化排样系统的开发

把碰撞理论应用在冲裁件优化排样中，通过增加对圆弧分段处理的步骤，采用直接对圆弧计算的方法，减少了计算复杂度。解决了排样件的非直线轮廓线性化所带来的离散精度与计算效率的矛盾。适合用于解决含有圆弧的复杂轮廓的同类零件优化排样。基于此算法作者开发了冲裁件的优化排样系统，自动计算零件间的碰撞距离、冲裁步距和最优排放角度。利用本研究的对头双排法裁料，可以把材料利用率从普通双排的76．6％提高到81．4％。     

基于遗传模拟退火算法的矩形件排样

将遗传模拟退火算法运用在矩形件排样中,利用遗传模拟退火算法的全局搜索能力,寻找出排样件最优的排样次序(排列最紧密),再结合基于局部板材利用率最高的填充算法不断填充板材,获得近似总体最优的排样结果。此结果适合应用于大批量、多种类的矩形件优化样。     

The behavior and effect of rare earth CeO<Subscript>2</Subscript> on <Emphasis Type="Italic">in-situ</Emphasis> TiC/Al composite

Rare earth CeO₂ was investigated as an additive for in-situ preparation of TiC/Al composites using XD (exothermal dispersion) + casting technology. Experiment results showed that an optimum CeO₂ addition of 0.5 wt pct promotes the generation and refinement of TiC particles, prevents the formation of Al₃Ti, increases the wettability between the TiC ceramic particles and the Al matrix, and improves the mechanical properties of composite. A corresponding thermodynamic model was proposed for the mechanism.     

聚合酶β在肝癌细胞DNA辐射损伤修复中的作用

利用第二军医大学裸鼠移植性肝癌细胞（ＳＭＭＣ－ＬＴＮＭ）和不同的ＤＮＡ聚合酶选择性抑制剂ＮＥＭ与ｄ２ＴＴＰ，探讨了肿瘤细胞核中ＤＮＡ聚合酶β参与γ射线辐射损伤ＤＮＡ修复的作用特点，结果表明，该酶参与真核细胞γ射线辐照损伤的ＤＮＡ修复合成，是一种重要的ＤＮＡ修复酶，与正常肝细胞相比，ＳＭＭＣ－ＬＴＮＭ肝癌细胞ＤＮＡ聚合酶β的ＤＮＡ修复合成反应速度快，修复能力强，提示某些肿瘤细胞中该酶的ＤＮＡ辐射损伤     

Effect of H_2 dilution on the structure and properties of nc-CrC/a-C:H coatings deposited by a hybrid beams system

Nanocomposite Cr C/hydrogenated amorphous carbon(nc-CrC/a-C:H) coatings were deposited by a hybrid beams system comprised of a hollow cathode ion source and a cathodic arc ion-plating unit with varying H_2 flow rates. The influences of H_2 flow rates on the morphologies, microstructures, and properties of the coatings were systematically studied. The morphologies and microstructures of the coatings were characterized by SEM, AFM, XPS, Raman spectroscopy, GIXRD, and HRTEM. The mechanical and tribological properties were measured by a nano-indenter, scratch tester, and ball-ondisk tribometer. The wear tracks were evaluated using 3D profilometer, optical microscope, and EDS analysis. It has been found that a moderate H_2 flow rate can effectively smooth the surface, enlarge the fraction of a sp~3 bond, and improve the properties. The coating exhibits the highest hardness and elastic modulus at the H_2 flow rate of 40 sccm. A superior combination of adhesion strength,friction coefficient, and wear resistance can be achieved at the H_2 flow rate of 80 sccm.