离散正交小波包及其在噪声抑制中的应用

研究有限长序列的小波包处理和噪声抑制的方法,方法用正交共轭滤波器构造有限维内积空间的正交值和分解及有限长离散小波包,分析了噪声的小波包分解系数的特性,并提出小波包变换域降噪的方法。     

WC—Co硬质合金刀片热丝法金刚石薄膜涂层附着力

用热丝法研究了ＷＣ－６％Ｃｏ硬质合金刀片金刚石薄膜涂层附着力。结果表明：采用温度为８０℃,（ＨＣｌ：ＨＮＯ３：Ｈ２Ｏ）（体积比）为１∶１∶１溶液对硬质合金刀片表面去Ｃｏ１５ｍｉｎ后,经４０ｕｍ金刚石粉及１．５ｕｍ金刚石加２０ｕｍＴａＣ混合粉进行超声预处理,结果表明,沉积的金刚石薄膜与硬质合金刀片基底具有良好的附着力,而经４０ｕｍ金刚石粉处理的薄膜涂层组织与附着力要好一些。     

微波合成PMMA胶乳粒子

在常压微波辐照下合成聚甲基丙烯酸甲酯（ＰＭＭＡ）单分散的胶体微粒。体系中未加表面活性剂和稳定剂,在透射电镜下观察粒子的形状和直径大小,并得出在引发剂浓度一定的条件下,微粒的体积与单体的浓度呈现线性关系,为我们合成一定大小的超细微粒提供了选择的条件。功力学实验表明,微波场下反应速度大大加快,反应是突变的,无恒速阶段。     

New evidence for the Qinghai-Xizang (Tibet) Plateau as a pilot region of climatic fluctuation in China

Over 40 a observed temperature data in 172 stations in China and historical proxy data were analyzed. Evidence suggested that during 1980–1994, the warmest year appeared first in southeastern part of the Qinghai-Xizang (Tibet) Plateau (henceforth SETP) and then gradually spread northwards and eastwards to eastern China. The climatic change on century time scale in recent 600 a shows 3 relatively warm and clod stages in China. Each warm and cold stage appeared first in Tibet Plateau (henceforth TP) and then in the Qilian Mountains, then in the eastern parts of China. The warm and cold stages in TP were 10–60 a earlier than in the eastern China. The facts show that TP is a pilot region of climatic fluctuation in China on the time scale shorter than 10³a.     

Calculation method of electronic structure and its application to (I h andI) fullerenes

A new calculation method was discussed to treat the Hückel Hamiltonian of any fullerene with a certain point group symmetry. This method was applied to calculating the electronic energy levels of icosahedral fullerenes C\-n(I\-h: n=60h 2, 0相似文献   

支持CAD／CAPP／CAM集成和并行的制造特征

由于设计和制造过程的复杂性,目前还没有一种有效的方法能彻底解决产品设计、制造和生产管理等生命周期内各个阶段的信息集成问题．探讨了并行工程下的ＣＡＤ／ＣＡＰＰ／ＣＡＭ的集成框架,提出了支持ＣＡＤ／ＣＡＰＰ／ＣＡＭ集成和并行运行的制造特征,并在商品化ＣＡＤ／ＣＡＭ软件ＵＧⅡ上进行了开发工作．该系统已通过纺织行业箱体、柴油机行业的油泵以及机床厂的主轴箱等多种零件考核．     

基于任务的产品工艺设计过程管理

在分析产品工艺设计流程现状的基础上,研究了现有ＣＡＰＰ系统中工艺过程设计和过程管理,提出了任务驱动型的ＣＡＰＰ思想．认为工艺设计的过程本质上是对任务完成过程的集合,通过对任务的生成、监控、设计、提交、签审、发放,正好控制工艺设计的流程,并在ＣＡＰＰ系统开发中进行了成功的尝试,为工艺设计的管理提供了一种可行的方法．     

吸收比-系数倍率法及其应用——水杨酸钠、安替比林和咖啡因的同时测定

用吸收比－系数倍率法同时测定撒痛风注射液中水杨酸钠、安替比林和咖啡因三组分的含量。它们的回收率分别为１００．７％～１０２．１％、９５．９３％～１０４．５％和９７．５７％～１０１．７％。     

On analytical treatment of all boundary and volume integrals in BEM

In this paper, the integrals appeared in BEM model for Poisson equation are all implemented analytically. Wherein, the boundary and the domain are discretized by linear boundary elements and linear internal triangle cells respectively. The closed formulations for all integrals are presented so that the computer effort for numerical solution is reduced considerably with higher accuray. The numerical example shows that the results are more accurate in comparision with Gaussian integration in the same discrezition. The basic idea of this paper could be extended to BEM model for Helmholtz equation and/or the time-dependent second other differential equations. Supported by the National Natural Science Foundation of China Tang Shaowu: born in 1971, Ph. D.     

关于二维Navier—Stokes方程的不稳定性

应用分层理论证明了二维Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程的ｃ＾２不稳定性,并给出了重要例证分析。