离心泵并联运行工况点的数值求解

建立了求解多台不同型号离心泵并联运行工况点的数学模型,给出了用数值计算中的“二分法”求解该模型的方法,并附有用Exce l计算的实例。     

Windows2000环境下实时控制系统的软件实现

文章介绍了在windows2000环境下通过编写WDM（Windows Driver Model）设备驱动程序实现实时数据采集和控制的一种方法。采用研华数据采集卡PCL818L产生中断信号．通过编写WDM驱动程序实现了在windows2000环境下转台的位置控制。并在实验中调试通过。实验结果表明：在采样频率为1KHz的情况下。控制系统很好实现了输出对输入的跟踪，证明了采用方法的正确性。该方法解决了windows2000环境下的实时性问题，为在windows环境下实时控制系统的实现提供了有益的尝试。     

换热器设计中适宜流体用量的确定

利用换热器的操作线来分析讨论流体用量对传热过程的操作费用和设备费用的影响，找出了换热器设计和选型中适宜流体用量的优化确定方法，简便，快捷，具有一定的适用性。     

一种自动布线方法：多级线探索法

本文介绍了一种在微机上实现的印制板自动布线方法──多级线探索法及其编程方法。这种方法是基于完备布线算法的概念，通过分析李氏算法和传统线探索法的不足之处而得到的。虽然它也是一种线探索法，但有较传统线探索法更强的探索能力，不需要结合李氏算法而能单独完成布线任务，是一种较理想的算法，通过实验获得了较为满意的效果。     

服务器系统的安全配置

为确保服务器的安全,在安装Windows2000系统时,对硬盘分区、组件和管理应用程序及安装顺序的选择应引起足够的注意。文章对Windows2000系统的补丁和安全配置的方法也作了必要说明。     

平差法预计矿区导线网精度

分析了矿区导线网精度预计经典方法存在的问题 ,推导出严密平差法精度预计的数学模型 ,并编制机算程序。     

Schwingfestigkeit von Schraube‐Mutter‐Verbindungen

High cycle fatigue of bolted connections Extensive tests regarding the influences on the fatigue of bolt‐nut‐connections of preloading with torsion, of preloading with yielding, of loading with superimposed bending and of the tested lot are processed. These influences are not yet known according to VDI 2230. New testing devices were designed for these tests, which allow a far less expensive operation and may easily be used for bolts of diameters up to M100 and testing frequencies up to 1000 Hz. The validity of fatigue resistance according to VDI 2230 is specified with respect to the test results. The determined influence of the tested lots is unexpectedly high. The manufacturing process of bolts should be improved to minimize this influence.     

An exploration of the problems of using function points mark II

Abstract. This paper examines critically the function point analysis mark II (FPA mark II) method of measuring the functionality of information systems. Although the focus of the paper is on FPA mark II as devised by Symons, both this and the Albrecht method, from which the FPA mark II was developed, are briefly discussed. The published attempts to validate FPA mark II are reviewed and then the problems encountered by the author in applying the approach are described. The final part of the paper is concerned with the fit between SSADM and FPA mark II.     

A scheme to randomly generate surface dust points for the 3D complex variable boundary element method (CVBEM)

A scheme to randomly generate dust points on the surface of a three-dimensional (3D) object is proposed. This scheme will potentially eliminate the bias of a density of points which are approximately equally spaced on the surface, as well as eliminate possible weighting requirements for areas of higher density. This method has the potential to reduce computational effort, as fewer points might be required to define the surface area. The global trial function vector can be assigned to these dust points and then entered into the complex variable boundary element method (CVBEM) commercial code. This scheme can be applied to each piece of a system that is comprised of a connected multiple geometry. A noticeable benefit of this approach is that the same problem can be studied several times, using a new random distribution of surface points each time. The smallest error can then be determined and that run selected. The Mathematica code used to generate the scheme is attached as an appendix.     

梯级水电厂集中控制运行模式探索

介绍了清江梯级电厂从单一电厂管理向多电厂集控管理转变的情况及存在的问题,并探讨了改进办法.