Vibration analysis of continuous maglev guideway considering the magnetic levitation system

The dynamic interaction between moving vehicles and two-span continuous guideway was discussed. With the consideration of the magnetic levitation system, the maglev vehicle/guideway dynamic interaction model was developed. Numerical simulation was performed to understand dynamic characteristics of the guide- way used in practice. The results show that vehicle speed, span length and primary frequency of the guideway have an important influence on the dynamic responses of the guideway and there is no distinct trend towards resonance vibration when f1 equals 1.0. The definite way is to control the impact coefficient and acceleration of the guideway. The conclusions can serve the design of high speed maglev guideway.     

斜连杆裂解工艺分析

介绍了柴油机斜连杆裂解工艺.研究了斜连杆较大外形尺寸对裂解连杆锻后控制空冷及裂纹扩展的影响及其结构不对称性对启裂的影响,分析了斜连杆在裂解试验和小批量试生产中出现的质量问题,并利用ABAQUS有限元对53D斜连杆进行了裂解启裂模拟.依据模拟结果提出了提高斜连杆裂解质量、优化斜连杆裂解工艺参数的合理建议.     

插电式燃料电池轿车的建模与仿真

简述了插电式燃料电池轿车的结构,重点介绍其各主要部件的模型结构和建模原理,最后在Matlab平台上将所建的整车模型与整车控制策略模型进行联合仿真,仿真分析结果验证了整车模型的正确性和整车控制策略的有效性.     

Comparison analysis of efficiency between double-synchronous step-down-stress and step-up-stress accelerated life tests

Double-crossed-step-stress (DCSS) accelerated life test (ALT) method is widely used for estimating the lifetime of products with high reliability and long lifetime. In order to further reduce the test time and test cost, a double-synchronous-step-stress (DSSS) ALT method which combines a double-synchronous-step-down-stress (DSSDS) ALT method and a double-synchronous-step-up-stress (DSSUS) ALT method is proposed. The accelerated stresses decrease and increase in a synchronous way with one step in the DSSDS-ALT and DSSUS-ALT methods, respectively. Monte Carlo method is adopted to simulate the two methods, and the validity and efficiency of them are demonstrated by the simulation results. In addition, a comparison analysis of efficiency between DSSDS-ALT method and DSSUS-ALT method is carried out. The result shows that the DSSDS-ALT method compared with the DSSUS-ALT method can significantly improve the test efficiency under the same test condition.     

有关地铁消防与火灾扑救的对策

地铁消防是个复杂的工程。 文章从地铁消防与火灾的特点出发, 对建立地铁消防的综合防火系统及地铁火灾扑救应注意的几个问题进行分析。     

基于ANSYS的汽车后桥焊接变形优化

建立了某汽车后桥的有限元模型,确定了材料热物理性能参数和热源模型,介绍了利用生死单元方法模拟焊缝金属的填充过程,并根据实际情况制定了焊接变形合格范围.采用ANSYS有限元仿真技术对后桥焊接变形进行了预测及优化,通过改变焊缝的焊接顺序及方向实现了抑制焊接变形的目的.结果表明,优化后后桥焊接变形量最小为1.3 mm,模拟计算结果与实测结果相吻合.     

丙型肝炎病毒NS3-NS4基因的表达及鉴定

目的　构建丙型肝炎病毒 (HCV)非结构蛋白NS3 NS4全长基因重组质粒并诱导表达 ,鉴定NS3 NS4蛋白的抗原性。方法　应用PCR技术从pUC19/HCV中扩增目的基因 ,构建重组表达质粒 ,进行原核表达 ,用SDS PAGE、ELISA技术对表达产物的抗原性进行鉴定。结果　成功构建、表达了重组质粒pBV2 2 0 /NS3 NS4 ,用 5 0份质控标准血清对表达蛋白质进行抗原性检测 ,与第二代诊断试剂相比 ,总符合率为 96 %。结论　全长NS3 NS4蛋白是一个优势免疫原性区 ,应该是HCVEIA诊断试剂的有效成分。     

城市轨道车辆的空转/滑行保护

本文在概述轮对空转/滑行保护系统的原理和发展的基础上,提出了城市轨道车辆空转/滑行保护的实施方案,介绍了其组成、特点、原理及系统的电路和程序框图.     

基于公路路基压实度标准提高的施工措施

针对新颁公路设计规范中提高了路基压实度标准,增大了施工难度的情况,分析了材料的压实特性和最佳含水量对压实施工的影响,并在分析各类压实方式的基础上,提出了各类压实机械使用中一些针对性措施。     

轮机管理专业口语教学的新探讨

本文针对我校轮机管理专业学生专业口语教学中存在的问题,结合自己的授课过程中的体会和所积累的经验,提出了几点行之有效的教学方法,共同仁参考。