Parametric analysis of wheel wear in high-speed vehicles

In order to reduce the wheel profile wear of highspeed trains and extend the service life of wheels, a dynamic model for a high-speed vehicle was set up, in which the wheelset was regarded as flexible body, and the actual measured track irregularities and line conditions were considered. The wear depth of the wheel profile was calculated by the well-known Archard wear law. Through this model, the influence of the wheel profile, primary suspension stiffness, track gage, and rail cant on the wear of wheel profile were studied through multiple iterafive calculations. Numerical simulation results show that the type XP55 wheel profile has the smallest cumulative wear depth, and the type LM wheel profile has the largest wear depth. To reduce the wear of the wheel profile, the equivalent conicity of the wheel should not be too large or too small. On the other hand, a small primary vertical stiffness, a track gage around 1,435-1,438 mm, and a rail cant around 1：35-1：40 are beneficial for dynamic performance improvement and wheel wear alleviation.     

基于熵权TOPSIS法的港口物流竞争力评价研究

在竞争日益激烈的港口业中,港口物流已成为各大港口竞争的一个重要突破点,港口物流竞争力的强弱对港口的发展以及港口城市乃至地区经济的发展都具有很大的影响。基于对港口物流资源的分析,从港口自然地理环境、港口基础设施条件、港口物流发展规模、港口城市综合实力4个方面构建了港口物流竞争力评价指标体系,采用熵权TOPSIS法对环渤海港口群中7个亿吨大港的港口物流竞争力进行了科学评价,并对其竞争态势做出了分析。研究结果表明,环渤海港口群港口物流竞争力水平悬殊,各港口应合理准确定位,通过错位发展和协同合作等方式谋求共赢。     

军用车辆交通风险控制问题研究

随着现代风险管理理论和技术的发展,风险控制的应用范围逐渐扩大,并逐步延伸到军用车辆安全管理工作中。通过对交通风险的控制来防范和减少交通事故的观念逐步得到重视,各种交通风险应对策略也逐步发展起来。从消除风险因素、降低风险发生的概率和降低风险后果三个方面来考虑,提出三种交通风险的应对策略：回避风险策略、减轻风险策略、转移风险策略。最后,依据交通风险应对策略,提出了军用车辆交通风险控制措施,为做好车辆交通事故预防工作提供理论参考。     

盐酸溶液中二环己基硫脲对304不锈钢的缓蚀作用

通过动电位极化曲线以及扫描电子显微镜观察,研究了四个温度下,二环己基硫脲（DCTU）对304L不锈钢在2 mol/L盐酸溶液中的缓蚀作用.结果表明：二环己基硫脲（DCTU）是304L不锈钢有效的阳极缓蚀剂,缓蚀效率随缓蚀剂的浓度和温度变化.二环己基硫脲（DCTU）在304L表面的吸附符合Temkeins吸附等温式,遵循化学吸附机理.相应的吸附动力学参数表明了金属基体与缓蚀剂间强烈的交互作用和自发吸附行为.     

解决北京市潮汐性交通拥堵的措施研究

依据北京市主要放射线道路的交通调查数据,以交通量、平均速度为指标定量分析了北京市市放射线道路交通流的潮汐特性．结合潮汐性拥堵成因分析,提出了交叉口可变导向车道系统、全路段可变导向车道系统以及分段式配时等解决措施,利用交通仿真方法对其进行了分析和验证．     

基于时间-费用约束的虚拟物流企业项目分解研究

考虑时间和费用约束条件下的虚拟物流企业项目分解.找出虚拟物流网络中的最短时延路,若该路的时延大于时间约束,则虚拟物流企业盟主认为不能在规定时间内完成该虚拟物流项目,拒绝该物流项目;反之,则从所有满足时间约束的路中挑出一条最小费用的路,通过此路进行分解,若时间和费用都满足虚拟物流企业盟主的期望,则接受该虚拟物流项目.并给出一个算例.     

基于物元分析的立交方案综合评价方法

针对立交方案的综合评价问题,利用物元分析理论进行研究,提出基于物元分析的立交方案综合评价方法.选取占地面积、通行能力、工程造价、施工难易程度等4大类13个指标作为评价因子,将方案分为优、良、中、一般4个等级,通过确定待评物元、建立节域物元矩阵、经典域物元矩阵,计算各评价因子权重和综合关联隶属度,得到不同方案及各评价因子对4个级别的隶属程度,通过比较选出了整体最优方案.结果表明,将物元分析理论用于立交方案的比选是可行的,不但能够比选出整体最优方案,而且能够分析出各评价因子之间的细微差别,具有较高的精确度.     

膨胀土室内试验判定方法探讨

以晋南地区膨胀土为例,对其进行了天然含水率、颗分、液限、塑限、收缩、自由膨胀率、SOkPa浸水膨胀率以及膨胀力等试验,通过用不同方法对膨胀土试验进行分析与判定,最后确定了较为适用的推荐法,供类似工程勘察试验参考。     

A two-step outlier removal procedure for surface reconstruction

Outliers in point clouds affect the performance of surface reconstruction directly. Most of outlier removal methods just remove those outliers far away from the real surface and are only applied to handle watertight surface. In this paper, a two-step outlier removal procedure is proposed to filter the point clouds acquired from the gray code and line-shifting technique. The first step is to remove the outliers far away from the real surface. Some feature points are extracted from the point clouds to construct an initial surface. The points with distances to the initial surface greater than a given threshold are removed as distant outliers. The retained points are linked into lines in each structured light sheet using their Voronoi diagrams. Some of lines which are very close to the real surface are removed as near outliers in the second step. The experimental results show that the proposed method is very effective in removing outliers for surface reconstruction. Foundation item: the National Natural Science Foundation of China (No. 30470488)     

Mechanical response of steel wire wound reinforced rubber flexible pipe under internal pressure

Steel wire wound reinforced flexible pipe in this study mainly consists of multiple anisotropic steel wire wound reinforcement layers and multiple isotropic rubber layers. Based on 3D anisotropic elastic theory, the analytic solutions of stresses and elastic deformations of steel wire wound reinforced rubber flexible pipe under internal pressure are presented. As the adjacent reinforcement layers with wound angle have different radii, the single reinforcement layer shows the effect of tensile-shear coupling. Moreover, the static loading test results of steel wire wound reinforced rubber flexible pipe under internal pressure are basically coincided with the calculated values by present method.