240／275系列机车柴油机传动机构中间齿轮装配破损故障的技术对策

根据沈阳铁路局近年240／275系列机车柴油机传动机构中间齿轮装配破损的数据统计，分析了故障发生的原因，提出了解决问题的技术措施。     

骨膦治疗骨转移癌25例疗效分析

对１９９３～１９９６年住院治疗的２５例骨转移癌患者采用单用骨膦治疗的方法，观察其对骨转移癌患者的止痛效果、骨病灶变化和不良反应。结果∶疼痛完全缓解５例（２０％），部分缓解１１例（４４％），无效９例（３６％），总有效率为６４％；骨病灶控制率为１２％（３／２５）；不良反应仅有轻微恶心。提示∶骨膦是治疗骨转移癌较理想的药物。     

有源滤波器改进控制方法的仿真研究

有源滤波器通常采用常规的三角载波调制PWM控制方法，具有开关频率固定、输出波形谐波分量较少的优点，但响应速度比较慢、精度低。通过增加输入电压补偿来改进三角载波调制的PWM控制方法，可以提高有源滤波器的补偿精度和实时性，减少开关损耗。MATLAB/Simulink仿真验证了改进方案的可行性。     

A rail roughness growth model for a wheelset with non-steady,non-Hertzian contact

This paper presents a model simulating rail roughness growth in which the interaction of a wheelset with the track is considered. The aim is to investigate any possible mechanism for roughness growth due to the coupling between the vertical dynamics, the torsional vibration across the axle of the wheelset and the non-steady contact mechanics. The time-domain simulations are carried out for a driven wheelset on tangent track. Both rigid and flexible are considered with parameter variations for moments of the wheelset, vehicle speeds and wavelengths of initial roughnesses. The 2D non-Hertzian and non-steady contact model used in simulations are based on influence coefficients obtained from a boundary element model. The nonlinear development of the rail roughnesses after millions of wheelset passages is also presented.     

On vehicle/track impact at connection between a floating slab and ballasted track and floating slab track's effectiveness of force isolation

When a vehicle runs over the connection between a floating slab track (FST) and ballasted track, wheel/rail impact may occur because of the stiffness difference in the two kinds of track, and thus a transition sector is usually included at the connection to smoothen the stiffness change. This phenomenon is studied by numerical simulation using a time-domain model for an idealised case without such a transition to determine whether it is actually necessary. Calculation results show that the wheel/rail impact load is moderate for a light FST and increases with the vehicle speed or decreasing the natural frequency of the FST. From simulation the wheel/rail parametric excitation is observed, as a result of variation in the stiffness of the FST with the period of the single slab length. The wheel/rail load due to the parametric excitation also increases with the vehicle speed. In addition, good performance of vibration isolation can be seen for the FST in terms of the force transmitted to the infrastructure.     

澳东到新加坡最佳航法

全面阐述了大型船舶从澳大利亚东部到新加坡的航路、航法、潮流及通过该区域的注意事项,并将最近走过此航路的体会进行了汇总,为船舶从澳东到新加坡航行提供了具体详尽的资料和指导。     

HX_D3型机车用DC110V电源装置

HXD3型机车用日本原装RFE081-A0型DC 110 V电源装置采用DC/DC变换形式,微机控制系统,功率元件为IGBT,整个装置包含两个独立的单元,互为备用,电源输入也采用了冗余设计,保证运行的稳定性和可靠性,文章对其工作原理进行了剖析。     

异步牵引电动机直接转矩控制系统建模与仿真

根据直接转矩控制原理及其特点,利用MATLAB/Simulink建立一种适合异步牵引电动机直接转矩控制系统的仿真模型,仿真结果验证了控制方法的正确性。     

基于单片机的智能电子遥控车位锁设计

文章运用PT2262/PT2267编解码器结合AT89C51单片机,实现的智能电子车位锁控制器,可以实现对遥控上锁、解锁、防盗、报警的功能,具有较高的实用价值。     

集束拉拔法制备钢纤维增强铜基复合导线

将直径0．26mm的铜包钢线集束装入铜管进行拉拔变形、800％淬火中间处理、拉拔变形，制成钢纤维增强铜基复合导线。钢纤维在铜基体中均匀连续分布，钢纤维由铁素体与马氏体双相组织组成，铜、钢界面呈锯齿状。铜体积比为57％、变形率为2．8时，复合导线拉伸强度达到1256MPa，相对电导率达到43．5％IACS，在大幅度降低铜含量的条件下，获得了良好的综合性能指标。