从钢轨异常波磨研究反思地铁设计

对近期北京地铁钢轨异常波磨治理研究过程从设计角度进行反思,包括振动控制技术的单一性、轮轨动力匹配等.提出今后轨道系统设计改进的思路与方向,包括设计应以实现其基本功能为核心、轨道减振设计应充分考虑其不利性、还"轨道减振"为"地铁减振"等,以及其他一些探讨性建议.     

现代有轨电车嵌入式轨道板的研究与设计

针对现代有轨电车建设周期短、景观要求高等特点,结合工程设计需求,研发了一种新型的现代有轨电车预制道床板轨道结构系统,此类结构采用高分子材料连接钢轨和道床,替代了传统扣件,突破了传统的有轨电车现浇道床的结构形式。对此新型轨道结构的组成及设计理论进行研究,室内试验及线上测试结果表明,该结构体系安全可靠,施工进度快,绝缘性好,并具有一定的降噪性能,为后续有轨电车轨道系统设计方案的研究提供了很好的借鉴和参考。     

如何调整柴油机气门间隙

通常车用M520B(GBC)、MC640A(GCH)、6140B(CQ261)、OM402(Benz2026)、6130(SX50)、8120F(LT665)柴油发动机调整气门间隙是要在冷车状况下、气门完全关闭、气门挺杆落至最低位置时进行.在调整前,先卸下气缸盖罩壳,并按发动机的旋转方向橇转曲轴,找出一缸压缩上止点.气门间隙的调整方法有记忆法、逐缸调整法、表达式法和经验法等.这里仅介绍方便、易记的表达式法.     

我国高等教育的现状分析及对策研究--从人的全面发展的目标定位审视

20世纪 90年代中期以来 ,高等教育改革在理论和实践两方面都取得了一定的成效。本文试图从人的全面发展的视角 ,在对其成效和基本走向进行梳理的基础上 ,指出已有的改革仍存在着与人的全面发展的目标定位不相符合的问题和倾向 ,具体表现为 :素质教育的形式化、表面化倾向 ;培养方式上过多的共性制约 ;忽视发展的可持续性 ;教育评价中的机械化、教条化倾向等 ,针对这些问题 ,提出了今后进一步推进改革的思路和对策     

基于抛石驳船的自动定位控制系统设计与实现

为了提高湖北襄阳沉管隧道建设中抛石驳船的位移精度,基于实时定位动态技术(RTK)卫星定位的抛石驳船位移控制系统,研究出一种粗定位和精定位相结合的移船施工方法。通过对抛石船特性的预判及工作特性的掌握,结合RTK卫星数据进行工程应用验证,根据目标船舶与当前船舶间的位置,采用粗控制、细控制相结合的多级模糊控制设计,兼顾绞车钢丝绳受力平衡性,为移船过程提供了较好的平稳性。经实船验证,本系统能够将位移精度控制在20 cm以内,在同级别工程应用中精度较高。     

Study of Engineering Geological Conditions and Railway Tunnel Scheme across Qiongzhou Strait（琼州海峡工程地质条件及铁路隧道方案研究）

The cross sea channel for the Qiongzhou Strait not only provides a solution for transportation, but also plays an important role in the political and economic development of the region. In addition, the project has an extensive impact on many fields, such as energy, national defense, science and technology, opening up and reform, comprehensive utilization and so on. It is a significant project to enhance China′s comprehensive national strength, defend the country′s territorial integrity and promote regional economic development. The geological conditions across the Qiongzhou Strait are complex. A large amount of existing engineering geological information and hydrogeological data are collected, based on which the seismic impact on subsea tunnels and the main geological conditions including tectonic structures are analyzed. Different options crossing the Qiongzhou Strait have been considered and compared in terms of engineering geology, environmental condition, as well as the construction feasibility. The analystical results indicate that a subsea tunnel has more advantages over a bridge. Because more complicated technical difficulties have to be solved for a highway tunnel which would potentially increase construction and operation costs, a railway tunnel scheme is recommended. Vehicles can be carried by trains through the Qiongzhou Strait railway tunnel. Based on the seabed topography and geological conditions, four preliminary railway tunnel routes are proposed. After a comprehensive comparative analysis, the railway tunnel route Ⅱ is identified to be superior to other alternatives and should be the basis for determining the final tunnel layout. The proposed tunnel cross section includes two railway tunnels and one service tunnel. All the three tunnels have the same structural form and dimension and will be constructed by shield.     

谈谈机制砂在工程中的应用

该文以永蓝高速公路工程应用机制砂于混凝土为实例,对机制砂混凝土与河砂混凝土的性能进行了比较,阐述了机制砂混凝土配合比设计中的几个关键步骤及应注意的问题,并阐述了机制砂代替天然砂应用到混凝土中的体会,指出了采用机制砂混凝土不仅可提升资源利用率,节约建造成本,又可保证工程质量。     

Challenges and Countermeasures in Construction of  Gaoligongshan Tunnel of Dali Ruili Railway（大瑞铁路高黎贡山隧道施工挑战与对策）

In order to resolve the challenges encountered in the construction of Gaoligongshan Tunnel such as soft rock deformation of inclined shafts, water drainage and protection of vertical shafts, TBM jam in crossing areas with adverse geology, solutions and key construction techniques are developed through theoretical analysis, field test, scheme optimization and staged review and summary. The performance results of field practice show that: (1)the goal of no damages and no replacement of the primary support can be achieved by adopting the comprehensive deformation prevention technique of "ring support early formation and quick closure", setting of proper excavation line curvature, and reinforcing of support; (2)the risk of vertical shaft flooding during construction in water rich weak granite can be greatly reduced by adopting the water control principle of "exploration for any excavation, plugging as the main method, and supplemented with drainage method" and the key pre grouting technique of S shaped deep boreholes; (3)the open type TBM can quickly and safely pass through the unfavorable mylonitic granite stratum by adopting the small pilot tunnel construction method, thus the fast and high efficiency construction performance of TBM can be fully utilized.     

力帆摩托力量达人挑战赛正式上线

7月28日，“力帆摩托力量达人挑战赛”活动官方网站www．Ifpower．cn正式上线；8月1日，线上报名活动盛大开启，“力量达人”挑战赛震撼登场!     

汽车万向节传动轴的选择和布置

万向节传动轴是汽车传动系的重要组成部件之一。传动轴选用与设计布置的合理与否直接影响传动系的传动性能。选用与布置不当会给传动系增添不必要的和设计未能估算在内的附加动负荷,可能导致传动