Studies on thermal fatigue in 3Cr2W8V die steel by positron lifetime and hardness measurements

Studies on thermal fatigue in 3Cr2W8V die steel have been carried out by using positron lifetime and microhardness measurements. It is found that the mean positron lifetime and the microhardness exhibit periodic up-and-down variations with an increase in the number of fatigue cycles. The experiments indicate that in the process of thermal fatigue there are two opposing effects on variation of defects: microdeformation and dynamic recovery and recrystallization.     

液体聚丁二烯的环氧化

分析了影响环氧化聚丁二烯合成条件的诸多因素、原料以及产物的结构，为该产品的实际应用创造条件。     

随钻气侵检测仪在胜利油田的应用

简要介绍了随钻气侵检测仪的结构特点、工作原理、现场模拟试验及应用情况。中原油田全尺寸实验井和胜利油田６口井的现场试验及应用结果表明，该仪器能实现早期气侵检测，比常规方法检测到气侵的时间明显提前，对高压气井和复杂地层井控具有重要的现实意义。     

Penicilloyl peptides are recognized as T cell antigenic determinants in penicillin allergy

Although hapten immune responses have been intensively studied in the mouse, very little is known about hapten determinants involved in human allergic reactions. Penicillins, as chemically reactive compounds of low molecular weight, constitute typical examples of hapten allergens for humans. Penicillins become immunogenic only after covalent binding to carrier proteins and in this form frequently induced IgE-mediated allergic reactions in patients subjected to antibiotic treatment. However, our previous data strongly indicated that penicillins also form part of the epitopes contacting the antigen receptors of beta lactam-specific T cells in allergic individuals. We have therefore investigated the molecular constraints involved in the T cell immune response to penicillin G (Pen G). Designer peptides containing a DRB1*0401-binding motif and covalently modified with Pen G via a lysine epsilon-amino group were found to induce proliferation of Pen G-specific T cell clones. A precise positioning of the hapten molecule on the peptide backbone was required for optimal T cell recognition. Furthermore, we extended these observations from our designer peptides to show that a peptide sequence derived from a natural DRB1*1101-binding peptide modified in vitro with Pen G, also acquired antigenic properties. Our data for the first time provide insight into the manner in which allergenic haptens are recognized by human T cells involved in allergic reactions to drugs and suggest possible mechanisms leading to the onset of these adverse immune responses.     

全球电信界的战略联盟

９０年代初，随着通信向全球化方向发展，发达国家各电信企业纷纷采用联盟的方式，相互联合，发挥各自优势，大举进军全球电信市场。面对这种联盟潮流，想要搭上全球通信的列车，发展中国家应该采取什么措施？坚持什么原则？本文作者对此进行了较深入的分析和研究，并对中国电信的发展提出了建议。     

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煤层气采出有扩散和渗流两个过程，比常规天然气层中的渗流方程复杂。煤层气由煤层流入井筒的过程为：随着煤层中水的不断采出，地层压力下降，吸附在煤层中的煤层气被解吸出来，并扩散至割理，割理中的气体渗流到达井筒。采用非平衡态吸附模型，研究单相煤层气在煤体和割理中的流动规律。在拟稳态流和不稳态流的数学模型假设下，用气体标准压力代替Ｌａｎｇｍｕｉｒ吸附公式中的压力，得到气层中标准压力所满足的方程。如果考虑无限大地层或有界圆形封闭和定压地层，最终得到井底无量纲准压力及其导数的解。     

西九龙填海区概念规划竞赛

In April 2001,the Govemment launched the West Kowllon Reclamation Concept Plan Competition to invite conceptral proposals for the development of a prominent 40-hectare waterfront site at the southern tip of the West Kowloon Reclamation into am integrated arts,cultural and entertainment district.The objective of the Competition is ,through the development,to enhance Hong Kong＇s positions as Asia＇s premiere centre of arts,culture and entertainment and create a new look for Victoria Harbour.The Competition attracted 161 entries,of which 71 were from Hong Kong and 90 were from elsewhere,covering some 30conntries.Adjudication of the Competition entries was made by a 10-member panel of Jury,chaired by Lord Rothschild.     

Certain characteristics of zirconium-containing anodic films on aluminum

Some data on zirconium-containing layers plasma-electrochemically (P-E) applied to A7 aluminum alloy (obtained by using x-ray spectral and diffraction analyses, electron microscopy, as well as measuring their thickness and visible light reflection) are discussed. The properties of the P-E applied structures formed under power-drop conditions are studied as functions of the potassium hexafluorozirconate bath temperature (20–70°C) and initial voltage (300–500 V). Original Russian Text ? K.N. Kilin, V.S. Rudnev, P.M. Nedozorov, T.P. Yarovaya, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 3, pp. 285–291.     

虚拟装配环境中的一种碰撞干涉检测方法

提出了在虚拟装配过程中零件与装配体碰撞干涉检测的一种方法。用投影轴算法检测出装配对象的碰撞,用坐标跟踪检测方法确定干涉余量值,并用连续包围盒对复杂和不规则的模型进行分割,通过这三种方法的配合使用,虚拟装配系统对干涉体进行了有效的、实时的、精确的检测。