轴向受力梁结构线弹性碰撞问题求解

研究了质点对轴向受力的Euler-Bernoulli梁结构任意位置的横向撞击问题.把撞击体系简化为质量-弹簧体系模型,采用积分变换方法,对撞击体系的控制微分方程、边界条件和连续条件进行Laplace变换,在频域内求得其解析表达式,然后采用Crump逆变换方法进行数值反演,得到时域内的各种动力响应.数值算例给出了撞击力、弯曲应力和剪力随时间变化的曲线,通过与有限元比较验证了本方法的正确性.最后研究了撞击位置、轴向压力、撞击质量、撞击速度和柔度系数等参数对撞击力的影响,得出了一些有用的结论.     

基于VRML97标准的混合渲染模型研究

虚拟现实场景需要混合自然场景和可视化数据等不同类别的对象,这时需要对不同对象使用不同的渲染模型.通过介绍在VRML97标准中实现各种渲染模型及其混合的方法.以校园虚拟环境为例实现了雨后彩虹的场景集成.     

Three-dimensional QSAR of HPPD inhibitors, PSA inhibitors, and anxiolytic agents: effect of tautomerism on the CoMFA models

The present study was design to examine the effect of tautomerism upon the CoMFA results. Three selected data sets involving protropic tautomerism, which are 21 p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors, 35 inhibitors of puromycin-sensitive aminopeptidase (PSA), and 67 anxiolytic agents, were used for this purpose. Atom-by-atom alignment technique was adopted to superimpose the molecules in the data sets onto a template. The structural alignments using different tautomeric forms had no significant difference except the atoms involved in tautomerism, which ensures, to a great extent, that the differences of the CoMFA results result primarily from the tautomerism. All-orientation and all-placement search (AOS-APS) based CoMFA models, in addition to the conventional ones, were derived for each system and proved to be capable of yielding much improved statistical results. In the cases of the data sets of HPPD inhibitors and PSA inhibitors, excellent AOS-APS CoMFA models (q2>0.8 with four components for the former and q2>0.7 with seven components for the latter) were obtained, and almost no significant difference in statistical quality was observed when using different tautomeric forms to derive the models. However, it was not the case when treating the data set of anxiolytic agents. The keto tautomer, which was the active form of the PBI type inhibitors, produced measurably better results (q2=0.54 with eight components) than that the enol one (q2=0.37 with five components), indicating the importance of selecting proper tautomer in the CoMFA studies. Furthermore, there existed some substantial differences of the electrostatic field contours between the two different tautomeric forms for all of the three systems considered, whereas the differences in the steric field contour maps were limited. This implies that the resulting new potent ligands may be quite different if one utilizes the CoMFA models of different tautomeric forms for guiding further structural refinements.     

结构状态智能模拟方法初探

该方法结合信息处理智能技术、科学计算可视化技术、计算机动态模拟及仿真技术、基于XML的可视化接口技术、软构件技术及工程数据库等技术,充分将先进的计算机科学技术与土木工程领域的结构分析与优化相结合,使其不仅能有效直观地反映问题,有效地辅助结构分析与优化,而且能够解决传统方法因数据不足或干扰给结构分析带来的困难,为结构受力动态分析及系统健康监测提供了先进的技术手段。提出了结构状态智能模拟环境的基本框架,并介绍了关键技术的应用。     

PLC与数字电子钟

在按时间控制的PLC控制系统中,正确处理定时是一个关键,本文介绍电子钟的显示数值范围、PLC控制的硬件接口及软件设计。     

用Visual C++创建一个不规则形状的窗口

阐述了如何用VisualC 创建一个不规则形状窗口的方法。     

多维数据立方体模型及其基于关系的实现

数据立方体模型是多维数据库和以多维分析为基础的联机分析处理技术的核心机制。本文参照当前对鑫维数据立方体模型的最新研究成果,提出了一种新的模型并且应用于OLAP服务器基于关系的实现。并且提出了实现的难点和改进的方向。     

基于数据仓库的集成质量决策支持系统的研究

论文讨论了数据仓库的基本原理,包括数据仓库的概念、功能、特点、逻辑结构和物理结构以及数据仓库系统,集成质量系统的内涵和质量决策支持系统的决策范围,提出了基于数据仓库的集成质量决策支持系统的体系结构及其开发流程和开发的关键技术。     

方向估计的神经网络计算

本文给出一种借助于二维神经网络构成的混合系统,用它来完成几种方向估计算法,这些算法包括：最大似然法,交替投影最大似然法,Ｍａｒｃｏｓ等人提出的无需特征分解的“传播算法”。利用神经网络对某些算法的快速性,该系统为实时实现目标的精确定位提供了一条新的,有效的途径。     

试用安全系统工程(ETA)图——分析锅炉事故

本文以某县火电厂一台AZD20—25/400型锅炉缺水干烧至熔的重大事故为例,试用安全系统工程(ETA)图树形分析法对事故发生的原因进行分析以查明事故原因,分清事故责任,拟定改进措施,并应用“人—机—环境”安全系统工程管理方法,就如何搞好锅炉的安全管理,防止事故重复发生,发表我们初浅的认识,其目的是对锅炉的使用管理作一点有益的工作。