Material constant sensitivity boundary integral equation for anisotropic solids

In this paper, the material constant sensitivity boundary integral equation is presented, and its numerical solution proposed, based on boundary element techniques. The formulation deals with plane problems with general rectilinear anisotropy. Expressions for the computation of sensitivities for displacements, tractions, strains and stresses are derived, both for boundary and interior points. The sensitivities can be computed with respect to the bulk material properties or to the properties of part of the domain (inclusions, coatings, etc.). To assess the accuracy of the proposed approach, the computed results are compared to analytical ones derived from exact solutions obtained by complex potential theory, when possible, or finite difference derivatives otherwise. Copyright © 2005 John Wiley & Sons, Ltd.     

机械锁定式地层测试技术研究与应用

机械锁定式测试技术操作简单，测试一次成功率高，资料录取准确全面，且测试结束后可直接进行封堵作业；解封时，机械锁紧产生一个向上的震击力，有利于解封，没有换位机构的测试阀在关井期间使管柱处于自由拉伸状态，有利于保护油管。在N阀上部管柱中加1-2根伸缩接头，便可用于海洋井测试。     

加氢裂化工艺辅助操作与管理专家系统的开发与应用

近来，专家系统技术的利用已成火炼油与石油化工专家们感兴趣的问题。本文评述了国外这些领域中专家系统应用的进展概况。同时，对我们开发的专家系统工具ＦＥＸＳ的性能作了简介。详述了工业加氢裂化装置辅助操作与管理专家系统的研制过程和系统配置，讨论了系统开发的经验。最后，评价了该技术在炼油与石油化工业中的应用前景。     

基于MPEG-4标准的VOD业务探讨

MPEG-4是动态图像专家组(MPEG)标准家庭中的一员，是国际化标准组织为多媒体通信制定的一种解决方案。介绍了MPEG-4支持的新功能和特点，并阐述了MPEG-4的关键技术，在此基础上对MPEG-4在视频点播业务中的应用问题进行了探讨。     

基于复数权值神经元的数字逻辑最稳健设计

复数权值神经元由于引入了多阈值逻辑而具有更强的性能,文中根据其数学模型,结合二进神经元稳健性的概念,提出了基于该神经元的稳健性定义.并结合定义,实现了基于单个神经元的基本数字逻辑以及异或运算的最稳健设计方案,从而证明了该稳健神经元实现任意数字逻辑的有效性和可行性,说明了其强大的处理能力.     

首钢2号高炉的技术进步

介绍首钢2号高炉大修采用的新技术、开炉操作和投产以来的生产情况。     

永州电力通信交换网集中操作和维护的实现

分析实现永州电力通信交换网集中操作和维护的必要性，介绍了实现程控交换机远程操作和维护的两种方式，总结在实践过程中所得到的经验和教训。     

紫外法测菜籽饼粕中硫代葡萄糖甙操作探讨

对用紫外法测菜籽饼粕中硫代葡萄糖甙过程中测试条件、操作质量等操作问题予以分析和探讨，以求提高测试结果的准确率。     

30t转炉三位一体护炉实践

以转炉终点高拉碳操作法及降低出钢温度等操作护炉为根本护炉手段，溅渣为主要护炉方法，贴砖作为护炉的辅助措施，有效地提高了转炉炉龄，达到了1万炉以上，实现了根据设备检修计划下炉。     

Hybrid numerical scheme for time-evolving wave fields

Many problems in geophysics, acoustics, elasticity theory, cancer treatment, food process control and electrodynamics involve study of wave field synthesis (WFS) in some form or another. In the present work, modelling of wave propagation phenomena is studied as a static problem, using finite element method and treating time as an additional spatial dimension. In particular, WFS problems are analysed using discrete methods. It is shown that a fully finite element-based scheme is very natural and effective method for the solution of such problems. Distributed WFS in the context of two-dimensional problems is outlined and incorporation of any geometric or material non-linearities is shown to be straightforward. This has significant implications for problems in geophysics or biological media, where material inhomogeneities are quite prevalent. Numerical results are presented for several problems referring to media with material inhomogeneities and predefined absorption profiles. The method can be extended to three-dimensional problems involving anisotropic media properties in a relatively straightforward manner. Copyright © 2006 John Wiley & Sons, Ltd.