编写公路建设项目后评价报告有关问题的探讨

简要介绍了公路建设项目后评价的概念、目的,论述了编写后评价报告需注意的几个问题,希望能够逐步完善项目后评价工作,对公路工程建设能很好地起到完善已建项目、改进在建项目、指导待建项目的作用。     

计算机联锁与四显示自动闭塞结合设计

在分析计算机联锁与四显示自动闭塞结合设计的基础上,对区间只有1架通过信号机和无通过信号机2种特殊情况下的结合设计进行深入研究,并介绍已成功应用的解决方案。     

探讨提高信号继电器技术性能的方法与途径

信号继电器作为铁路信号的重要执行元件,其产品性能和质量应得到相应提高与发展。通过现状分析,指出AX系列继电器产品质量和性能改进的重要问题,并提出应研制适合于高速铁路和客运专线使用的新型继电器。     

中餐菜单的翻译障碍及翻译方法

随着我国旅游业的发展和2008年北京奥运会的临近,中餐菜单翻译日益显示出其重要性和必要性。文章分析了中餐菜肴及主食翻译的障碍,并结合实例归纳了几种常用的翻译方法。     

Uncertainty due to discretization on the ALE algorithm for predicting water slamming loads

Numerical uncertainty due to discretization on the Arbitrary Lagrangian-Eulerian (ALE) Finite Element method is investigated in the study. The paper quantifies uncertainty using two ITTC recommended methods, and also applies a constant Courant-Friedrichs-Lewy (CFL) number based discretization approach, instead of performing the independent grid and time-based discretization recommended by ITTC. As a case study, water entry of a flat bottom rigid and flexible plate is simulated considering various entry velocities. The total slamming loads and structural responses on both the rigid and elastic bottom plates are predicted and validated against available experimental data. Results indicate that numerical errors due to discretization differ in the various parameters and from case to case. They do affect the analysis of slamming loads and associated structural responses, and the hydroelasticity analysis as well. The hydroelasticity effects on the slamming force generally increase as the entry velocity increases, however, the quantitative results differ much for models with different grids. For example, when the hydroelasticity effect is estimated using the finer model, the deviation of the total slamming force on the elastic plate relative to the one on the rigid body are 56%, 57%, and 63% respectively for the three constant entry velocities, whereas the estimations are −27%, −4% and 3% with the coarser model. The study concludes that the uncertainty due to discretization in ALE is not just case-specific, but also parameter specific. The uncertainty quantification procedures with a constant CFL number based refinement are recommended to investigate the uncertainty comparing to the individual grid and time step study, in particular for the ALE solution where the time step is adjusted automatically as the grid changes. Thus, consideration should be given to updating the ITTC guidelines to incorporate the constant CFL based discretization approach.     

多规则融合的船体小组立部件装焊作业调度算法

针对小组立装焊作业周期长、场地资源利用率偏低等问题。以最小化装焊作业完工时间为目标,考虑了装焊过程中的先序约束,人力资源约束和场地空间资源约束,建立小组立装焊作业的调度模型；设计了多规则融合的船体小组立部件装焊作业调度算法；利用最化小总时差规则优化装焊任务序列,利用最短可用模式规则优化任务的工人分配,利用改进的初始配置规则与最大化残余空间利用率规则优化小组立装焊的空间布置。最后,从实际船舶制造过程中收集的数据进行验证,结果表明,装焊作业完工时间缩短了21%,证明了该算法的有效性     

基于设计波法的超大型集装箱船疲劳强度评估

基于BV规范中的疲劳强度计算评估方法,论述了设计波法的基本原理,给出了确定设计波载荷的基本流程和疲劳累计损伤组合计算的方法,并据此对某超大型集装箱船的重点位置结构进行疲劳强度的计算分析与评估。     

直管站段体制下增加货运保价收入的有效途径

通过对广州铁路集团公司近年来货运保价运输收入下降原因进行分析,采取下放权限,科学制定考核指标,建立有效的考核机制,优质服务,规范管理等各项措施,充分调动直管站段的积极性,有效地扭转了下滑趋势,增加了货运保价收入。     

高职院校汽车实训教学探讨

文章从实训环境、师资力量、仿真教学等几个方面就如何提高实训教学的质量和效率、有效提升学生的操作技能，培养出优秀汽车运用技术人才进行了一些探讨，以期对汽车专业人才培养提供一定的借鉴意义。     

某公路大桥引桥抗震性能研究

根据某大桥引桥的结构特点,建立了空间动力计算模型,研究了结构动力特性;应用反应谱分析方法和非线性时程方法,研究了某特大桥引桥在E1和E2地震作用下的地震反应,并对E1和E2地震作用下的抗震性能进行了验算。