FEA for designing of floating raft shock-resistant system

Choosing the equipment with good shock-resistant performance and taking shock protection measures while designing the onboard settings, the safety of onboard settings can be assured when warships, especially submarine subjected to non-contact underwater explosion, that is, these means can be used to limit the rattlespace (i. e. , the maximum displacement of the equipment relative to the base) and the peak acceleration experienced by the equipment. Using shock-resistant equipments is one of shock protection means. The shock-resistant performance of the shock-resistant equipments should be verified in the design phase of the equipments. The FEA (finite element analysis) software, for example, MSC. NASTRANw, can be used to verify the shock-resistant performance. MSC. PATRAN and MSC. NASTRAN are used for modeling and analyzing the floating raft vibration isolating equipment. The model of the floating raft and the floating raft vibration isolating system are theoretically analyzed and calculated, and the analysis results are in agreement with the test results. The transient response analysis of the system model follows the modal analysis of the floating raft vibration isolating system. And it is used to verify the shock-resistant performance. The analysis and calculation method used in this paper can be used to analyze the shock-resistant performance of onboard shock-resistant equipments.     

Visual C#2005中设置的使用

.NET框架允许用户创建和访问在各应用程序执行会话之间保持的设置,设置的创建、管理和使用非常重要。Visual C# 2005可以在C#应用程序中使用设置来存储和管理从属于应用程序和用户的设置,可以在设计时创建新的设置,可以在运行时访问设置以及可将多组设置合并到应用程序中。     

曲线区段接触线拉出值的确定

分析了曲线区段接触线拉出值超标的原因,提出了影响拉出值的各主要因素的计算式,并在忽略了一些影响列车振动的次要因素的条件下,得到了曲线区段弓-网位置的动态变化情况,进而讨论了接触线拉出值的选取原则。     

5800DWT杂货船总体和结构设计的特点

本文介绍了5800DWT杂货船总体和结构设计的特点，可供同类型船设计、研究参考。     

3500m^3全压式近海液化气船储罐安全阀选型计算实例

本文主要介绍了LPG船安全阀选型计算的方法，以及在计算过程中各种参数的选取。     

Do motor-vehicle users in the US pay their way?

Governments in the US spend over a hundred billion dollars per year to build and maintain roads and provide a variety of services for motor-vehicle users. To pay for these infrastructure and services governments collect revenue from a variety of taxes and fees. The basic objective of this paper is to compare these government expenditures with the corresponding user tax and fee payments in the US. At the outset I argue that the such comparisons tell us something about the equity but not necessarily the economic efficiency of highway financing. I then present four different ways one might tally up government expenditures and user payments, depending on the extent to which one wishes to count “indirect” expenditures (e.g., on prosecuting car thieves) and non-targeted general-tax payments (e.g., severance taxes on oil). I make a comprehensive analysis of all possible expenditures and payments, and then compare them according to three of the four ways of counting expenditures and payments. The analysis indicates that in the US current tax and fee payments to the government by motor-vehicle users fall short of government expenditures related to motor-vehicle use by approximately 20–70 cents per gallon of all motor fuel. (Note that in this accounting we include only government expenditures; we do not include any “external” costs of motor-vehicle use.) The extent to which one counts indirect government expenditures related to motor-vehicle use is a key factor in the comparison.     

80m钢桁梁浮拖架设施工技术与安全稳定控制

菏日铁路复线京杭运河大桥跨主河道80m钢桁梁,采用旁侧、低位浮拖,再顶升横移的架梁方案,获得成功。介绍拼梁平台、河岸码头、纵移滑道、浮船加固、牵引动力系统等主要施工设施和非悬臂浮拖的货船压舱水的组成、模拟试验、正式浮拖等关键技术环节的处理方法和安全稳定控制措施。     

三相10 kV TSC无功补偿装置保护系统研究

对三相TSC(晶闸管投切电容器）无功补偿装置的保护系统进行了研究，较详细地分析了可能发生的故障原因、现象，进行了理论计算，提出了保护措施，为保护系统的设计提供了一定的依据。样机试验证明，该保护系统较全面地考虑了各种故障保护，简单、实用、可靠，其性能达到设计及工程要求。     

船舶柴油机-调距桨自动控制推进系统实时仿真

本文论述了基于微型电子计算机(笔者使用TRS-80微型计算机)对船舶柴油机-调距桨联合自动控制系统进行实时仿真的方法。并用该实时仿真系统获得了船舶推迸系统的动态特性曲线。解决了这个多输入、多输出、非线性的复杂自动控制系统的动态特性求解问题。本文重点探讨建立该实时仿真系统的两个关键问题:(1)对象的非线性;(2)微型计算机速度慢与实时仿真要求速度快的矛盾。     

基于微机的电压与无功优化自动控制

提出了一种基于微机的变电站自动化系统，该系统在无需增加任何硬件装置的条件下就可在当地计算机后台监控系统中用软件模块来实现变电站的电压和无功的自动调节。