计算机联锁系统仿真平台的研究

通过软件编程构建一套完整的计算机联锁系统仿真平台.介绍仿真平台的设计方法,联锁程序采用模块化设计,实现计算机联锁的各种功能,具有一定的完整性.根据不同的站场图、不同的操作平台可以方便地更改人机界面及操作方式,为适应不同厂家提供的联锁设备提供很好的仿真平台.     

地铁车站空气品质的评价与探讨

介绍了室内空气品质的定义,归纳了地铁车站空气品质的评价方法和标准.经研究对比指出,在对地铁车站空气进行评价时使用卫生标准比舒适性标准更为合适.影响地铁车站空气品质的主要因素有空调系统的材质问题、室内空气的二次污染、由于活塞风带来的隧道空气等.最后,提出了一些相关的改善措施,如清除和控制室内污染源、发挥通风有效性、装屏蔽门、制定针对地铁站的空气质量标准等.     

坞式闸室混凝土裂缝控制措施

坞式闸室在以往的工程中经常会在闸室底板和倒角产生混凝土裂缝,底板裂缝通过后浇带设计加以解决,后浇带处理不当会产生人为裂缝、同时也会带来施工不便。探讨坞式闸室底板整体浇筑的可行性,研究采用三维有限单元法模拟船闸坞式闸室的施工过程,分析指出闸室底板和倒角可能产生裂缝的成因,提出应用预应力加固技术防治混凝土裂缝,同时提出了预应力布置参数。计算结果表明,施加预应力后可有效降低底板和倒角处的拉应力,使其低于混凝土应力控制标准,达到了防治裂缝的目的。     

CORRELATIONS BETWEEN BLOOD PRESSURE AND BODY WEIGHT, SERUM LEPTIN IN HIGH CALORIE DIET-INDUCED OBESE RATS

Objective To examine the change of body weight （BW） and blood pressure （BP） in obese rats, clarify relationships between BP and BW and other factors. Methods Male Spraque-Dawley rats were fed either with normal diet （ND） or high calorie diet （HC） for 20 weeks. BW and BP of tail artery were observed biweekly and tetraweekly respectively; serum leptin and fasting insulin （FINS） were detected by enzyme-linked immunoadsordent assay （ELISA） and radioimmunoassay （RIA） respectively. Fasting plasma glucose （FPG） and free fatty acid（FFA） were measured by conventional means. Results BW, abdominal fat weight （AFW）, ratio of abdominal fat weight to body weight （RF/W）, systolic blood pressure （SBP）, diastolic blood pressure （DBP）, serum levels of leptin and FINS, FPG, FFA increased in the HD group after 20 weeks diet intervention （P〈0.05 or P〈0.01 ）. SBP was strongly correlated with BW, leptin, FINS and FFA （P〈0.05）, DBP was correlated with FFA （ r =0.47, P〈0.05）. In addition, leptin was positively correlated with BW, AFW, RF/W, FINS and FFA （P〈0.05 or P〈0.01 ）. Conclusion In this study of high calorie-diet induced rats, the gain of BW is accompanied by increased BP. The obese rats have hyperleptinemia, hyperinsulinemia, hyperglycemia and dyslipidemia which may have important effects on the development of obesityrelated hypertension. RF/W is the key factor in which affect serum leptin level.     

Dynamic demand estimation and microscopic traffic simulation of a university campus transportation network

Abstract

This article documents the authors' experience with the modeling, simulation, and analysis of a university transportation system, using the TRansportation ANalysis and SIMulation System (TRANSIMS). The processes of data preparation and network coding are described, followed by the algorithm developed to estimate the dynamic 24-hour demand, which includes a procedure for estimating the ‘desirability’ of the different parking lots from readily available data. The dynamic demand estimation algorithm is validated by comparing estimated and observed parking lot occupancies, where it is shown that the algorithm is capable of replicating observed results. Finally, an example is included to demonstrate how the developed model can be used in campus transportation planning. Besides serving as a first case study for using TRANSIMS to model a university campus, the study's contributions include the development of a procedure for parking lot desirability ranking and a practical procedure for estimating dynamic demand on university campuses.     

牵引变电所继电保护测试软件研究

为了实现牵引变电所继电保护的自动测试,设计了一种新的继电保护测试软件。本文介绍了单体和整组继电器测试数据的处理方法、测试软件系统的数据库逻辑结构及程控电源命令字的生成过程。     

软弱围岩大断面隧道环形开挖预留核心土法相关参数研究

结合湖北省境内某隧道项目,采用三维建模模拟环形开挖预留核心土法在不同核心土长度、台阶长度、进尺深度、衬砌施作时间下围岩变形情况,找出环形开挖预留核心土法各因素对围岩稳定性的影响,获得经济合理的开挖参数。总结了施工关键点,为广大工程技术人员提供参考。     

基于ANSYS有限元分析的海底管道变形数值模拟

某海底管道由于拖锚损伤导致局部失效变形。文中基于变形管道的偏移量、着力点破坏程度、塑性变形区域等信息,通过ANSYS有限元分析软件对管道在锚拉力作用下的变形过程进行数值模拟,计算变形管道所受的最大拉力和弯曲角度等参数,并验证整个变形过程。结果表明,该海底管道在至少2 657 k N的外力作用下牵引拉伸导致变形失效。     

我国部分港口规划存在的环境问题分析及对策建议

“十五”期间,我国港口建设飞速发展,港口吞吐能力大幅增加,但仍难以满足港口物流、客流的需求。“十一五”时期,我国港口交通仍将快速发展,如何体现“预防优先,保护为主”的环境政策,协调港口发展与环境保护之间的关系,是我国各港口总体规划亟待解决的问题。本文从目前港口总体规划入手,分析其存在的环境问题,并提出解决这些问题的对策和建议。     

基于极限约束法的高强度钢板成形性分析及轻量化选材

基于对有限元逆算法的改进,提出了极限约束法.它在计算时只考虑单元边界节点的两种极限约束状态,通过极限约束评判法则来快速、有效地预测板料的成形性;再通过对边界节点约束力的优化计算,可以得到最佳成形结果.文中还对汽车保险杠采用新研发的高强度钢板的成形性进行模拟试验,作为极限约束法的实例验证.