用逼近法计算横截面为椭圆形(圆形)储油罐的储油体积

得出的结果是当储油罐横截面椭圆的长半轴为a,短半轴为b,储油横面弓形的高为h（高h垂直于长半轴）,油罐的长为L时,体积可用[π/2 a1T1(x) a3T3(x) … a2k 1T2k 1(x)]abL去逼近（其中：T2k 1(x)为2k 1阶契比晓夫多项式,a2k 1=16/(2k 1)^2[4](2k 2)^2]π,x=h-b/b,k=0,1,2,……）。     

基于倒函数的立交匝道设计方法研究

文章将倒函数的概念、原理应用到立体交叉线形优化设计中,提出一种采用倒函数y=a/x作为立体交叉右转匝道线形的方法,分析了该函数线形相对一般采用的缓和曲线-圆曲线-缓和曲线的比较优势,并结合计算实例介绍了用倒函数设置立交右转匝道的具体求解方法。     

基于DEA-BPNN模型的高速列车运行线效率计算方法研究

利用数据包络分析（DEA）方法进行效率计算时，若有新增参评样本则下阶段计算时旧样本的效率计算结果可能会随之改变，针对此问题，引入反向传播神经网络（BPNN），基于含偏好序的DEA-CCR模型效率计算结果进行训练，构建DEA-BPNN效率计算模型，在不影响旧样本阶段计算结果的前提上计算新增样本效率。以杭深线厦深段高速列车运行图为例，根据运行线技术指标，利用DEA-BPNN高速列车运行线效率计算模型对2021年第1季度和第2季度厦深段运行图的本线高速列车进行效率计算，研究结果表明，第1季度厦深段本线列车平均效率为0.946，而第2季度本线列车平均效率达到了1.048，说明2021年第2季度厦深达速调图后运行线效率相较上一季度有较大提升。     

供水管路网络模拟计算

介绍了解多元非线性方程组的Ｂｒｏｙｄｅｎ法和供水管路网络的Ｂｒｏｙｄｅｎ法模拟计算；给出了其计算模型、计算框图、计算过程和计算结果。与以往的牛顿－拉夫森等计算方法相比，其计算收敛稳定性大大提高，收敛速度大大加快（平均收敛迭代次数减少一半以上）；改进了管路网络模拟计算的计算方法，提高了计算质量。     

型钢水泥土组合梁抗弯模型试验研究

为研究钢－水泥土组合结构的抗弯性能，对这种组合梁的三种形式（“一隔一”、“二隔二”、满堂“）进行模型试验研究。通过对这三种形式组合梁的实验数据处理和分析，提出了三种形式组合梁的组合刚度计算方法。本文对ＳＭＷ工法的设计计算具有实际的参考价值。     

复杂地质条件深埋特长隧道地应力场智能反演研究

为提高复杂地质条件深埋特长隧道地应力反演的精度和效率，构建了一种基于构造分析+RBF（径向基函数）神经网络的复杂地质条件深埋特长隧道地应力智能反演方法，该方法的主要流程包括：首先通过区域地质条件及构造分析，建立隧址区三维地质模型，通过海姆假说和金尼克假说共同确定构造应力边界条件的范围，作为智能反演的训练样本，利用RBF神经网络方法计算寻优，获得最优应力边界条件，再以此最优应力边界条件进行地应力反演计算。选择西南地区某深埋特长隧道作为研究对象，将建立的地应力场智能反演方法应用于实际工程，并将反演计算获得的地应力值与实测地应力值进行拟合对比，其中最大主应力反演值拟合误差总体在10%左右，拟合精度近90%，说明该方法可行且反演计算结果较合理。     

在有过冷度条件下的波节管式汽—水换热器热工计算方法的探讨

本文介绍了在有过冷度条件的下汽－水换热器热工计算的一种新方法，此方法与常规计算方法相比较，计算精确度较高。     

含沙多相流对金属管道腐蚀-磨损及其监测

根据近年来资料，系统介绍了含固体颗粒和沙的流体对金属管道腐蚀－磨损的计算公式和检测技术。讨论了API－14E公式、Salama修正公式、Lots方程等磨损预测模型，分析了主要影响因素，重点介绍抗磨损阻力ECR和临界流速等判别指标，包括其意义、测量和计算方法、判别准则和具体应用。此外还介绍目前流行的沙磨损监测技术：（1）检测磨损量的电阻式传感器，传感器结构原理、相关计算公式及具体检测方法；（2）检测沙量的声波检测器，它们的测量原理和具体应用方法等。     

按地基为弹性半无限平面计算排水明槽结构

本文主要阐述为使结构计算更好的反映实际的受力情况，对置于填筑路基层上的大断面长条矩形排水明槽结构，按地基为弹性半无限平面体进行计算实例。排水明槽按一次超静定的闭合框架计算，在求解基本结构上的冗余力和底板（基础梁）地基反力、剪力和弯矩计算时，均考虑了底板（基础梁）在弹性半无限平面地基上的变形影响。比较基础梁地基反力按直线分布假定的计算和按地基为弹性半无限平面计算地基反力按曲线分布，两者存在的明显差异，主要是前者完全没有考虑地基的物理力学性质和梁的变形所致。     

圆管外表面轴向椭圆裂纹应力强度因子的有限元研究

采用1/4节点奇异单元,建立了求解圆筒外表面轴向椭圆裂纹应力强度因子的断裂力学分析模型,分析了应力强度因子随圆筒外径与内径比k=ro/ri、椭圆率a/b及裂纹的相对深度a/t的变化规律,并结合VB编制出了求解圆筒外表面椭圆裂纹应力强度因子的自动分析软件。     

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.     

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。     

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.     

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。     

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。     

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.     

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。     

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.