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。     

混合动力列车的应用前景展望

本文阐述了混合动力列车的技术特点及其相应优势与劣势,同时介绍了其在国内外的研究动向,并对其应用前景进行了展望。尽管该类新型铁道车辆的续航能力、电池寿命以及成本等相关问题目前仍有待改善,但以其对城市环境的美化作用与优越的舒适驾乘性能,以及高效节能、绿色环保的显著优势,依然不失为一类充满前景的新型轨道交通运输方式。     

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。     

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。     

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.     

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.     

Evaluation of pedestrian crosswalk level of service (LOS) in perspective of type of land-use

In India pedestrians usually cross the road at mid-block crosswalks due to ease of access to their destination or the development of adjacent land use types such as shopping, business areas, school and residential areas. The behaviour of pedestrian will change with respect to different land use type and this change in behaviour of pedestrian further reflects change in perceived level of service (LOS). So, it is important to evaluate the quality of service of such crossing facilities with respect to different land-use type under mixed traffic conditions. In this framework, pedestrian perceived LOS were collected with respect to different land-use type such as shopping, residential and business areas. The ordered probit (OP) model was developed by using NLOGIT software package, with number of vehicles encountered, road crossing difficulty as well as safety considered as primary factors along with pedestrian individual factors (gender and age), land-use type and roadway geometry. From the model results, it has been concluded that perceived safety, crossing difficulty, land-use condition, number of vehicles encountered, median width and number of lanes have significant effect on pedestrian perceived LOS at unprotected (un-signalized) mid-block crosswalks in mixed traffic scenario. The inferences of these results highlights the importance of land use planning in designing a new set of pedestrian access facilities for unprotected mid-block crosswalks under mixed traffic conditions. Also the study results would be useful for evaluating pedestrian accessibility taking into account different land-use type and planning required degree of segregation with vehicular movement at unprotected mid-block crosswalk locations.     

盾构隧道管片接头抗剪力学性能研究

通过对南京长江盾构隧道环向管片接头进行的三组原型抗剪(无螺栓剪切、有螺栓逆剪和有螺栓顺剪)加载试验,分析研究了管片接头在剪力作用下的受力、变形和破坏特征,给出了管片接头混凝土接触面的静摩擦系数,得到了接头剪力主要由混凝土接触面承担、破坏形式为连接斜螺栓剪切延性破坏的结论。通过对管片结构的有限元数值模拟计算得出:接头处的剪力与轴力比小于接缝面的摩擦系数,管片不会发生相互错动,结构是稳定的。     

高含硫净化装置水冷却器腐蚀控制研究与应用

通过对装置样品管束进行局部取样检测分析,得到了高含硫净化装置水冷换热器腐蚀机理;通过分析电化学腐蚀、点腐蚀的形成原因,以及循环水系统中影响水冷却器管束腐蚀的因素,提出了高含硫净化装置水冷却器防腐措施：采用黏泥剥离,改善循环水的水质情况;对设备定期进行化学清洗,除去其表面的黏泥及污垢,减缓电化学腐蚀的发生速率。实践表明：采用该防腐措施,设备的腐蚀速率得到明显控制,为高含硫净化装置水冷却器腐蚀控制和下一步研究提供了参考和借鉴。     

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。     

深基坑坑底土体抗隆起稳定性的验算方法辨析

深基坑抗隆起验算是基坑设计中的一项重要内容。本文对现有技术标准中有关基坑抗隆起稳定性验算的内容进行了系统的梳理,并就验算模式的适用条件、计算参数的取值和抗隆起安全度的指标值等提出了一些建议,推导和完善了部分计算公式,以供同行参考。     

硫磺沥青路面技术在广西的应用前景分析

文章以广西高速公路建设为背景,从技术性能、社会经济效益角度入手分析了硫磺沥青路面技术的优势,介绍了硫磺沥青路面技术在广西地区的工程应用情况,并阐述了该技术使用过程中面临的问题及应对措施。     

山地旅游轨道交通线路规划的适应性评价

山地景区地势复杂,其发展普遍受交通所限,为了提高山地景区的运营效益、带动经济发展,国内部分景区规划和修建了山地旅游轨道交通。本文列举了山地旅游轨道交通特征及线路规划模式,从地理环境、自然环境、供需环境及与常规公交的关系四个角度分析,对应建立四个子系统,并选取具有山地旅游轨道交通特性的评价指标体系,利用层次分析法和变异系数法组合赋权重,运用灰色关联分析法的评价模型,据此判断线路规划方案适应性的优劣。     

Estimation of value of travel time reliability

In mode choice decision, travelers consider not only travel time but also reliability of its modes. In this paper, reliability was expressed in terms of standard deviation and maximum delay that were measured based on triangular distribution. In order to estimate value of time and value of reliability, the Multinomial and Nested Logit models were used. The analysis results revealed that reliability is an important factor affecting mode choice decisions. Elasticity is used to estimate the impacts of the different policies and system improvements for water transportation mode. Among these policies, decision maker can assess and select the best alternative by doing the benefit and cost analysis based on a new market share, the value of time, and the value of reliability. Finally, a set of promising policies and system improvement of the water transportation were proposed.     

防风网工程防撞措施研究

防风网工程是一种应用于港口露天煤堆场的环保构筑物,然而煤堆场内转运煤炭的货车数量多且出入频繁,给道路周边的防风网带来了安全隐患。文章分析了港区货车撞击防风网等构筑物事故发生的原因,介绍了防撞措施的设置原则,提出了刚性防撞、柔性防撞、绿化带防撞、夜间防撞等被动防撞措施。     

Comparison of results of two models of transportation demand in Hong Kong: CDAM and a version of microTRIPS

CDAM is a new computer program for solving the combined trip distribution and assignment model for multiple user classes, which enables transport planners to estimate consistent Origin-Destination (O-D) matrices and equilibrium traffic flows simultaneously if the trip production and attraction of each user class at zone centroids are available. This paper reports an application of CDAM to the central Kowloon study area in Hong Kong. The coefficients of the model related to the components of generalized costs are calibrated on 1986 travel data. A comparison of results of CDAM and a version of MicroTRIPS models of transportation demand in Hong Kong are presented. Finally, some conclusions are drawn and the advantage of the CDAM are discussed.     

巴巴奥约河大桥主墩承台水化热分析

文章采用有限元结构软件对巴巴奥约河大桥主墩承台的水化热进程进行分析,并介绍了大体积混凝土温度和应力的电算方法,对主墩承台温度分布变化规律进行了探讨,为承台大体积混凝土施工提供参考。     

旺村电站至桂江河口河段设计最低通航水位分析

文章依托旺村电站至桂江河口河段航道工程,介绍了设计最低通航水位的确定方法和思路,并基于西江（干流）水位顶托对旺村电站至桂江河口（支流河口段）水位的影响分析,确定了相关设计最低通航水位指标值,提出了该河段设计最低通航水位分析的要点及注意事项。     

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.