Analysis of Travel Characteristics of Elders in Beijing

On the basis of the information concerning individual travel behavior of partial elders in the data of travel survey in Beijing in 2005, the article analyzes and compares the individual travel characteristics between the elders and the 19–60-year-old population in the aspects of travel ratios, travel time, travel distances, departure time, travel modes, and travel purposes, analyzes the rules of variation of elders' travel behaviors with age, compares the differences of the travel behaviors of the elders between the eight urban districts and the outer suburb districts. It also studies the travel characteristics and attributes of the travel behaviors of the elders' home-based travel chain. The research indicates that differences of the travel characteristics between the 61–65-year-old elders and the 19–60-year-old contrastive population are small, the travel ratio of the elders is slightly lower than that of the contrastive population, the travel mode is mainly walking, and the flexibility level is significantly lower than that of the contrastive population. Besides, the travel distance of the elders falls off sharply with age, and other factors, such as sexes, spouses, family structures, etc., have significant impacts on the elders' travel behaviors.     

碎石桩在公路软土地基路堤中的应用

通过介绍碎石桩在公路软土地基中的应用概况,详细论述了碎石桩的加固机理、设计原则及施工技术要点。     

基于Superpave技术的沥青路面再生研究

废旧沥青路面再生是沥青路面修建的新技术,它不仅节约资源、减少道路修建成本,而且改善相关环境.然而,这些材料在Superpave设计规范中没有详细的说明,因此,有必要了解这些废旧沥青混合料是否能够在Superpave设计中使用.通过使用Superpave技术对沥青再生混合料进行的试验,表明掺配废旧沥青混合料能减少新的沥青含量,增加沥青砼间接拉伸强度.同时,掺配废旧料的沥青再生砼也在增强沥青路面的车辙抵抗性能、沥青砼间接回弹模量和影响疲劳寿命方面起着重要的作用.     

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二次过街信号设计对于行人通过大型信号交叉口具有非常重要的作用。本文提出了行人信号相位与原机动车信号相位进行叠加组合的相位设计方法，并分析了在不同的机动车信号相位条件下和二次过街设置方式下的行人信号相位设计方案。为对可选信号相位设计方案进行比较，本文构建了各周期内各驻足区行人平均最长等待时间模型，并建立了评价行人二次过街信号相位设计方案的仿真分析模型。最后针对一个实际交叉口，应用提出的信号相位设计方法和仿真模型进行了分析研究。     

Research on Direct Torque Control System Based on Induction Motor

IntroductionIn 1 980 s,Professor Depenbrock proposed aunique control scheme called direct torque control( DTC) for induction motor,which combined sim-plicity and robustness with excellent performanceof torque control for AC drive system[1,2 ] . Theprogress in power electronics and microprocessortechnology made higher inverter switching frequen-cy possible,which directly leads to the betterchar-acteristics of the DTC system.The DTC simulation system based on MAT-LAB is established in th…     

浅谈内河船员假证屡禁不绝的原因与应对办法

内河船员持假证上船任职的现象，已到了非治不可的地步，文章分析了内河船员假证屡禁不绝的原因，提出了遏制船员假证的对策。     

数字摄影测量在道路选线中的应用

计算机技术的飞速发展,给道路设计带来了极大的方便,数字摄影测量在道路选线中的应用,其过程主要是利用全数字摄影测量系统（VirtuoZo）生成DEM（数字高程模型）,由建立的带状DEM内插出带状横断面,自动绘制公路路线平面地形图;再根据平面曲线各个测点的平面坐标和带状DEM内插线状纵断面,最后将线状纵断面进行平滑处理.     

深层水泥搅拌桩处理软基施工摔制与质量检测

深层水泥搅拌桩进行软基处理已得到广泛应用。结合工程实例，介绍了深层水泥搅拌桩施工中施工准备、试桩、施工工艺流程、施工注意事项、安全技术措施等内容，以及常用质量检测方法。     

HXD1型机车顶盖焊接工艺及质量控制

介绍了HXD1型机车顶盖制造工艺要求以及在制作过程可能出现的问题,提出解决问题的方法,实现了设计意图。     

拉车长阀紧急制动的试验分析

介绍了DK-1型电空制动机与F8型车辆制动机列车制动试验台拉车长阀紧急制动试验情况,分析了列车管管径及布置对列车紧急制动的影响,提出了机车车辆列车管布置、设计的建议。