管道的泄漏及带压处理方法（一）

介绍了管道的泄漏形式，泄漏原因及在管道不停止输送的条件下消除泄漏的最有效途径，确保管道安全连续输送。     

管道局部泄漏的动态处理技巧

简述了管道泄漏对生产的影响及动态密封技术的基本原理的特点，并以两个成功的实例介绍了在不停工条件下处理管道局部泄漏的技巧。     

《缠绕式垫片》国家标准综述及贯彻

缠绕式垫片是石油、化工、发电等行业中管道、阀门及压力容器等密封部位上不可缺少的一种静密封元件。文章首先指出了原国家标准中存在的几个问题。并详介了新国家标准的构成，制定依据及适应范围，缠绕式垫片的压缩与回弹率、应力松弛率及密封泄漏率等三项指标的验证试验。     

液体管道破损处泄漏特性实验环道设计

文中借鉴顺序输送环道设计的有关经验,利用相似原理,设计了一个采用多种环道结构和元件的实验平台。该设计根据实际事故情况设置泄漏孔形状等边界条件,可最大限度模拟实际泄漏事故过程,研究各运行工况下管道破损处的出流特性和扩散规律,为泄漏量预测、泄漏后停泵方案优化等提供依据。     

高压换热器Ω密封环腐蚀泄漏案例分析及改进措施

某加氢装置反应产物与原料油换热器E304/AB采用的是Ω环式的密封结构,该高压换热器管程密封部位多次发生腐蚀泄漏。针对该加氢装置换热器腐蚀泄漏的原因进行了分析,根据换热器密封结构、设备材质、操作介质成分、温度、压力等影响因素采取了相应的改进措施,有效地解决了该换热器腐蚀泄漏的问题。     

直埋热水管网井室保温管道穿墙密封结构方案

文中通过对直埋敷设热水管网检查井室在管道进井壁处的防水密封情况进行分析,找出造成泄漏的原因,包括穿墙密封件结构和管道沉降造成泄漏的因素。分析这些泄漏因素,研究实现有效密封的技术关键点,设计一种新的保温管道穿墙密封件的结构,为直埋敷设热水管网检查井室管道穿墙密封提供解决方案。     

氯乙烯贮罐泄漏原因分析及对策

文中介绍了氯乙烯贮罐泄漏的概况。通过泄漏现场勘查和取样,从设计结构、材料选择、制造质量、生产工艺等几个方面出发,采用金属材料学和化学分析的方法,全面分析了发生泄漏的原因。该泄漏是由于设计选材不当、焊缝余高过大、排污管与罐体焊缝未打磨至与母材平齐、焊后未进行消除应力热处理、罐体安装角度有误及操作介质中氯化物超标等造成,并提出了避免类似泄漏发生的相应对策。     

基于ABAQUS的八角垫密封法兰效果评价

为分析八角垫密封法兰机理以及对密封过程中法兰结构强度和密封性能等进行研究,采用ABAQUS建立有限元模型对其真实预紧过程进行模拟。结果表明:八角垫密封面上应力非均匀分布,在内侧两密封面上靠近上下倒角处应力值最大并最先发生屈服,同时该部位接触应力最大,因此是密封的主要作用部位;按Waters法求得的最小螺柱预紧力预紧时有效密封长度较短,为增强密封效果,宜进一步增大螺柱预紧力;施加最大螺柱预紧力时,法兰结构强度和刚度均能满足要求,且有较大安全裕量,表明法兰相对螺柱较"安全"。     

海底管道负压波泄漏检测失效分析及解决方案

某海底原油管道设置了负压波泄漏检测系统,但该系统误报漏报情况非常严重,无法实现有效的泄漏检测报警功能。根据负压波泄漏检测的基本原理,结合现场仪表的安装设置情况及管道的实际运行工况,具体分析了负压波泄漏检测系统失效的主要原因。根据现场情况,提出了采用次声波泄漏检测系统的解决方案,介绍了次声波泄漏检测系统的组成及技术参数。经过放油试验,证明该系统可以有效地实现泄漏的报警和定位。     

管道带压封堵技术

根据应用实践，介绍了输油管道在不停输时，在流体动态条件下，将热塑性、热固化的密封剂用大于系统内介质压力的外部推力使其充满泄漏部位进行堵漏的原理、夹层、操作及注意事项的情况并展示了封堵效果。     

Analysis of factors affecting the choice of route of pedestrians

Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD).

An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip.

It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links.     

实现多组态计量软件集中监控的可行性分析

天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本.     

注汽管道承压能力评估和实物试验验证

基于失效评估图技术对某注汽管道进行了承压能力评价,给出了管线在不同腐蚀壁厚情况下的极限承压能力和极限裂纹尺寸。并利用实物爆破试验验证了评价方法的安全性和有效性,通过对爆破断口进行宏观和微观分析,发现管段的开裂属于脆性开裂。     

Non-parametric analyses of efficiency of airports

This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress.     

波纹管应力分析研究进展

评述了波纹管应力理论研究方法的进展情况，围绕解析法、工程近似法和数值法，对波纹管理论研究中的一些主要成果作了较详细的回顾和总结，对各种研究方法作出了评价，展望了亟待解决的一些问题。     

输油管道中原油乳状液的流变性研究

原油乳状液的流变性是原油开采后在管道中输送的重要研究方面,为了更好地研究这一性质,采用电动搅拌机、偏光显微镜以及流变仪等仪器来测定不同含水率的原油乳状液在不同条件下的黏度,观测不同含水率的原油乳状液在偏光显微镜下的形态。并且分别对原油乳状液的黏度与含水率之间的关系以及与剪切速率之间的关系进行研究,初步确定了所测区块原油乳状液的转相点以及该区块原油乳状液的流变特性,为生产中的油气集输提供了理论依据。     

城市轨道交通杂散电流监测系统概述

介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。     

埋地管道防腐保温层失效评价

明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。     

Preliminary results of an analysis of areas of influence in Shanghai

The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda.     

Direct analysis of the perceived importance of attributes of reliability of travel modes in urban travel

Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area.