并行敷设旧管道的防腐蚀维护

对某并行敷设旧管道防腐层绝缘性、阴极保护技术水平、均压线分布状况进行了分析，举例阐述了并行敷设旧管道在后期维护中存在的防腐蚀技术不均衡、防腐层大修不均衡等维护措施不利的问题，探讨了防蚀保护效果不佳的基本原因，并简要论述了提高并行敷设管道防腐蚀效果的措施。     

油田埋地管线无源阴极保护

埋地管线无源阴极保护是一种新技术，它与外加电流阴极保护的差别在于利用管道内介质与大地的温差，借助半导体器件的塞贝克效应产生电流。通过室内试验找出了仪器所需的最低温差，现场试验表明该技术是先进、实用的油田埋地管线防腐技术，有着较为广阔的应用前景。     

城市埋地旧管线阴极保护改造的技术实施

通过试验研究和工程实践，提出了一套适用于埋地旧管线增施阴极保护的技术。联合采用变频选频法、包覆试验和馈电试验，结合对 旧管道的涂层状况和钢管状况进行检测和评估，综合性地确定所需保护电流密度和阴极保护设计。对城市埋地旧管线实施阴极保护改造 后些工程实践证明，这些方法和技术是有效的和可行的。本文对阴极保护工程实践中的几个关键技术进行了讨论，并丙次提出电绝缘是埋地旧管线实施阴极保护改造的必要条件之一，应     

油田集输管线的联合阴极保护

外防腐层与阴极保护是油田集输管线最经济有效的防腐蚀措施,但是管线的阴极保护往往与油田地面设施的防雷/静电技术不匹配,管线的阴极保护效果受影响。文中介绍了采用联合阴极保护油田集输管线的极化水平不均的问题。从绝缘接头绝缘性、管线阻性以及站内地面设施接地等方面进行了阴极保护系统调查,指出绝缘接头失效、现有接地系统是导致电流漏失的因素。对集输管线原有阴极保护系统提出了在恒电位仪输出阴极串联具有强制分流的阴极接线箱、绝缘接头保护、接地改造等改进措施。     

锌合金在储油罐接地技术中的应用

锌合金用储油罐的避雷防静电接地极，不仅可以更好地改善接地条件，而且可使储油罐底板外侧仅需很小的外加电流就能得到完全保护而避免腐蚀。锌合金接地极也可以兼作牺牲阳极，提供低电阻接地和阴极保护的双重功能。     

埋地管线的阴极保护技术——管道腐蚀与防护讲座之四

介绍了阴极保护原理和技术方法,阐述了埋地管线上发生微电池和长线宏电池腐蚀的机制,牺牲阳极法和外加电流法阴极保护技术在埋地管线上的应用,它们的电极过程、物质变化和电流分布。论证阴极保护的主要参数及合理选择保护度和保护效率的关系。提出了对阴极保护技术继续研究和发展的几点建议。     

城市地下管线阴极保护工程的应用实践与发展

本文简要介绍了国内外对城市地下管线实施阴极保护工程的一些现状、经验、存在的问题和发展趋势。明确提出了对城市地下管线实施涂层加阴极保护的必要性。呼吁尽早实施国家立法、企业立法。应要求新建项目地下管线可制订规划，分期分批实施阴极保护补充改造工程。阴极保护工程的质量控制是影响防腐蚀效能的重要环节。阴极保护系统运行期的良好日常管理维护，可以显著提高效能，延长服役寿命。在阴极保护工程技术中尚存在许多现代技术     

GPS同步中断法在阴极保护有效性评价中的应用

采用GPS同步中断法对港枣线通电/断电电位进行测量,进而根据阴极保护有效准则对港枣线阴极保护有效性进行系统评价。结果表明：干线管道的阴极保护有效保护率达82.5%,调整恒电位仪输出后,干线管道的阴极保护有效保护率可达95.5%。欠保护管段集中在兖州站-滕州17#阀室站间。阴极保护失效可能与管道防腐层出现电流疑似泄漏点及交流杂散电流干扰有关。     

交流杂散电流对埋地钢质管道阴极保护电位的影响

为了明确交流杂散电流干扰对油气管道阴极保护电位的影响，通过设计的2套实验装置和恒电流极化法，分别研究了受有效电流密度为30、100、250 A/m²的交流干扰，阴极保护电流密度分别为-0.17、-0.25、-0.62、-2.26 A/m²时(对应电位约为-0.75、-0.95、-1.1、-1.2 V)的X70钢油气管道阴极保护电位变化情况。结果表明，交流杂散电流干扰下，阴极保护电位一般会正向偏移，但在阴极保护电位较正时，也可能发生负向偏移。可见，存在交流杂散电流干扰时，油气管道阴极保护电位会发生变化，从而影响阴极保护效果。     

杂散电流干扰下管道密间隔电位检测数据处理方法

管道的密间隔电位测试(CIPS)的数据,能有效评价管道的阴极保护水平.但在检测中,各种途径的杂散电流所产生的IR降经常能对测试数据产生影响.消除这种影响的方法是在测试桩处安装智能数据记录仪,自动记录测试桩处同步断送电的管地ON/OFF电位波动情况.利用智能记录仪记录的数据对CIPS数据进行更正.现场实践证明:这种方法能有效排除杂散电流IR降对CIPS检测数据的影响,获得更加准确的极化电位用于评价阴极保护水平.     

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.     

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。     

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。     

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.     

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。     

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。     

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.     

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。     

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.