城市轨道交通接触网防雷技术应用

随着气候变化、极端恶劣天气增多,轨道交通架空接触网雷电防护在研究相对滞后的情况下,已无法满足实际需要。通过介绍滓滨轻轨在架空接触网防雷方面所采取的改进措施以及取得的成效,为同行提供借鉴或参考。     

车载永磁发电机的研制

介绍了一种新型车载永磁发电机的研制过程。该电机和发动机形成一体,其设计方法有别于常规的发电机。采用电磁场的计算方法,根据静态气隙磁场分布状态调整该电机结构参数;用实际运行状态进行仿真,计算全调速范围内的输出特性,为HEV(混合动力汽车)的动力供应策略选择提供其输出能力Map图。     

基于二次跳时序列的UWB无线电通信系统性能

讨论了扩展二次跳时序列和一般二次跳时序列及其特殊形式序列的构造，比较了它们的汉明互相关特性．在此基础上，比较了在PPM调制方式下基于这几类二次跳时序列的UWB系统的误码率，并给出了数值结果．研究结果表明，这几类二次跳时序列系统误码率相当一致，但一般二次跳时序列集具有更多的序列数目．     

两种大间隙磁流体密封聚磁结构性能的对比

用有限元方法分析了对齿聚磁结构的大间隙聚磁性能,并与同尺寸的单侧极齿聚磁结构比较.结果表明,对齿聚磁结构的磁通汇聚作用较好,在沿平行于密封间隙的方向上中间极齿间隙磁场的最大磁通密度差远大于单侧极齿聚磁结构,密封性能约为单侧极齿聚磁结构的2倍,而且有利于克服高速旋转时作用在磁流体的离心力,以适应高速转动轴类的磁流体密封.     

细粒式橡胶沥青混合料在广祠高速公路加铺改造中的应用

沪渝高速（G50）广祠段路面改造中采用粗粒径高掺量的废胎胶粉制备橡胶沥青,通过优化配合比设计,调整混合料生产及施工工艺,实践表明,ARAC13型橡胶沥青混合料表现出良好的路用性能,可为高温多雨地区类似工程项目提供借鉴。     

A HOS-based blind signal extraction method for chaotic MIMO systems

A novel method to extract multiple input and multiple output （MIMO） chaotic signals was proposed using the blind neural algorithm after transmitting in nonideal channel. The MIMO scheme with different chaotic signal generators was presented. In order to separate the chaotic source signals only by using the sensor signals at receivers, a blind neural extraction algorithm based on higher-order statistic （HOS） technique was used to recover the primary chaotic signals. Simulation results show that the proposed approach has good performance in separating the primary chaotic signals even under nonideal channel.     

UWB技术在船舶避碰系统中的应用

在NLOS环境下分析了超宽带（UWB）信号及信道传输特性,针对信号的传播特性给出了UWB信号应用于船舶避碰的工作原理,确定合适的接收设备以实现信号的可靠接收,从而对两船之间的距离及方向进行实时监测,使工作人员根据判断结果采取一定的避碰措施,保证船舶航行安全.     

城市轨道交通架空接触网雷电防护

我国城市轨道交通架空接触网导线离地高度和线路绝缘水平与电力系统10 kV配电线路相当,雷电防护应以防感应雷为主.本文对接触网感应过电压进行了仿真研究,利用统计方法计算了接触网感应雷击跳闸率,提出了采用避雷线、绝缘子保护间隙和串联间隙金属氧化物避雷器3种雷电防护措施.     

一种连铸连轧低碳低合金钢板的组织特征

利用光学显微镜、直读光谱仪和电子探针研究了一种用连铸连轧工艺生产的低碳低合金钢板的组织特征及成分偏析.结果表明：该钢板的显微组织以珠光体/铁素体带状组织为主要特征,并且随距钢板表面距离增加,带状组织中珠光体比例增加,铁素体平均晶粒尺寸增大.锰含量沿垂直带状组织方向波动,在珠光体条带内含量较高,而在铁素体条带内含量相对较低.钢板中心偏析明显,形成较多长条状硫化物夹杂.     

Effects of the guideway's vibrational characteristics on the dynamics of a Maglev vehicle

The levitation control system in an electromagnetically levitated vehicle controls the voltage in its winding to maintain the air gap, which is the clearance between the electromagnet and the guideway, within an allowable range of variation, while strongly interacting with the flexible guideway. Thus, the vibrational characteristics of the guideway play an important role in the dynamics of Maglev (magnetically levitated) vehicles that utilise an active electromagnetic suspension system. In this study, the effects of the guideway's vibrational characteristics, such as natural frequency and damping, on the dynamics of the Maglev vehicle UTM-02 are numerically and experimentally analysed. From these analyses, the coupled equations of motion of the simplified vehicle–guideway model with three degrees of freedom are derived. Eigenvalues are calculated and frequency response analysis is also performed, in order to obtain a clear understanding of the dynamic characteristics resulting from the guideway's vibrational characteristics. To verify the numerical results, air gap tests of the urban Maglev vehicle UTM-02 are also carried out. These results lead us to recommend that the natural frequency of the guideway be decreased by increasing mass density rather than by decreasing rigidity, and that its damping ratio be increased in the Maglev vehicle UTM-02 employing a five-state feedback control law as a levitation control law.