高温许用应力下调对CASE 2180钢使用的影响

介绍了美国机械工程师协会（American Society of Mechanical Engineers,ASME）和日本经济贸易产业省（Ministry of Economy,Trade and Industry,METI）相关标准对CASE2180钢高温许用应力进行下调的情况,并对高温许用应力修正后的CASE2180钢管的最小壁厚进行核算,从而说明高温许用应力下调对CASE2180钢的影响及存在的问题。     

Safety of ocean shipments of plutonium between Europe and Japan

Abstract

Sandia National Laboratories (SNL) has conducted an extensive study of emergency response planning applicable to sea transport of plutonium for the Japan Nuclear Cycle Development Institute (JNC). This work covered four separate areas to better define the accident environment for long range sea transport of nuclear materials. A probabilistic safety analysis evaluated technical issues for the transport of plutonium between Europe and Japan. An engine room fire aboard a purpose built ship was used to analyse the vulnerability of plutonium packaging designed to International Atomic Energy Agency (IAEA) standards. A comprehensive corrosion study estimated the time required for sea water to breach a containment boundary in submerged generic plutonium packaging. A survey of worldwide commercial recovery capabilities provided a compilation of information on the capabilities of salvaging high value cargo from sunken ships. This paper addresses salvage modes from harbour depths to the deepest ocean trenches. Previous studies (J. L. Sprung et al., SNL reports SAND98-1171/1 and SAND98-1171/2, May 1998) included a probabilistic risk assessment of the overall safety, source term evaluations and finite element structural dynamics calculations to determine the effects of ship to ship collisions on nuclear material containers and the effects of ship fires on transport packaging as determined by actual fire experiments conducted on board a test ship. The previous studies, together with this work, form a comprehensive technical basis that encompasses the overall safety of sea transport of plutonium between Europe and Japan. Based on these technical analyses, transport of nuclear materials by sea in Type B packaging, approved in accordance with US Nuclear Regulatory Commission (NRC) and IAEA regulations, and carried in purpose built ships with adequate surveillance, has a very high degree of safety for the failure modes studied. Non-purpose built ships do not have the redundancy in safety features provided by the newer purpose built ships. However, SNL studies on non-purpose built ships have shown accident environments to be within NRC and IAEA regulatory assumptions for Type B packaging. These studies were carried out for both structural ship to ship collisions and engine room fires by analysis (for the collisions) and direct experimentation and analysis (for the fires). Thus, land transport mode regulations are applicable for sea transport accident conditions.     

新闻发布系统的数据库建模和系统实现

本文介绍了一个典型的新闻发布系统数据库的建模和系统实现,重点是其数据库的逻辑建模,以及ERA模型在逻辑建模中的应用。在建模过程中,应用了数据库规范化理论,减少了冗余数据,提高了系统的可维护性。最后,简要说明了建立在数据库建模基础上的系统实现。     

PKUMoDEL:模型驱动的开发和语言家族支持环境

OMG发布的UML语言家族和MDA架构促进了模型驱动软件开发的思想成为现实.建模语言版本升级或者面向不同领域的语言家族新增成员的不断出现,要求模型驱动开发环境除了使得模型成为软件开发生命周期中的主体之外,还应该具有元模型的定义和操纵能力.模型驱动的开发和语言家族支持环境PKUMoDEL是基于MOF的元建模环境和基于UML2.0的建模环境的集成体,很好地解决了诸如元模型的定义、扩展和评估、建模工具的自适应和演化、不同类型工具之间的集成、模型复用、从模型到运行环境的直接映射和部署等问题.     

A unified formal basis for the CASE tools system

XYZ system is a CASE tools system based on a temporal logic language XYZ/E which can represent every essential feature of conventional HLL's (sequential or concurrent), specifications of different levels, production rules, operational semantics of graphic languages in a uniform framework. With this formal language as the common basis, all the CASE tools including various kinds of graphic tools for distributed process, concurrent programs with phased memory and sequential programs, tools for verification, rapid-prototyping, language transformation, and module management can be connected freely to form more sophisticated and integrated systems.     

高应变动力试桩的误差分析

相对静载试验而言,高应变动力试桩的误差来源要丰富得多。本文较系统地对这些误差进行总结,提出了浅层次、中层次和高层次的误差的概念,并通过工程实践分析说明。对如何减小误差、更好地应用和发展高应变动力试桩技术提出建议。     

MIS设计方法及走向

ＭＩＳ设计方法是ＭＩＳ研究的很重要的方面，也是ＭＩＳ设计成败的关键因素之一。本篇论文从实际出发分述了常用的几种ＭＩＳ设计方法及其发展走向，提出了ＭＩＳ设计方法面临变革的问题。     

Scheduling for Concept-Oriented Rapid Prototyping

In this paper scheduling strategies for a rapid prototyping system are discussed. Our rapid prototyping system is able to deal with several CASE-tools and generate code for models of heterogenous domains. By using the emerging CASE Data Interchange Format CDIF the model data of CASE-tools is represented tool-independent. This tool-independent layer serves as a basis for analysis, simulation and code generation. The generated code is partitioned in tasks which must be scheduled as fast as possible using a real-time operating system to support high performance applications. We classify scheduling requirements for the constraints of rapid prototyping and present a new scheduling strategy called pseudo-rate scheduling which significantly improve the execution speed of rapid prototyping applications. Additionally, we provide a set of equations to estimate schedulability. Experimental results demonstrate the main advantages of our scheduling strategy.     

The Application of Save Functions of SDL in Communication Systems

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