城市轨道交通车辆产品标准体系探索

分析了国内外城市轨道交通车辆产品标准体系的现状,重点介绍了城市轨道交通车辆产品标准体系的总体要求、结构搭建、产品标准的制修订,以及标准的实施和改进措施。     

高架快速路上跨宝鸡东编组站方案比选

宝鸡市斗中路高架快速路,跨越宝鸡东编组站的10股轨道线和铁路专用线,同时桥下的城市主干路以框架桥的形式下穿宝鸡东编组站。桥位处需保留现状的地面交通、铁路框架桥和周围的高层建筑,桥址处空间局促,建设条件复杂,导致桥梁墩位布置困难。桥梁的布置方案与施工方案相互影响和制约。上跨方案是控制整条快速路的关键节点。综合考虑主墩的合理位置、恰当的孔跨布置和适宜的施工方案,对矮塔斜拉桥、刚构桥等方案进行详细的对比分析,确定采用(97+97)m的转体刚构桥方案。该方案的安全性和经济性均较优。该桥方案的研究过程和方法,为类似的复杂城市环境下,建设高架桥梁跨越铁路编组站提供参考和借鉴。     

Fast-charging station choice behavior among battery electric vehicle users

This study explores how battery electric vehicle users choose where to fast-charge their vehicles from a set of charging stations, as well as the distance by which they are generally willing to detour for fast-charging. The focus is on fast-charging events during trips that include just one fast-charge between origin and destination in Kanagawa Prefecture, Japan. Mixed logit models with and without a threshold effect for detour distance are applied to panel data extracted from a two-year field trial on battery electric vehicle usage in Japan. Findings from the mixed logit model with threshold show that private users are generally willing to detour up to about 1750 m on working days and 750 m on non-working days, while the distance is 500 m for commercial users on both working and non-working days. Users in general prefer to charge at stations requiring a shorter detour and use chargers located at gas stations, and are significantly affected by the remaining charge. Commercial users prefer to charge at stations encountered earlier along their paths, while only private users traveling on working days show such preference and they turn to prefer the stations encountered later when choosing a station in peak hours. Only private users traveling on working days show a strong preference for free charging. Commercial users tend to pay for charging at a station within 500 m detour distance. The fast charging station choice behavior is heterogeneous among users. These findings provide a basis for early planning of a public fast charging infrastructure.     

地铁供电系统中压开关柜电流分析理论和方法

通过分析地铁供电系统不同电压等级的设备电流特征,确定35 kV电压等级设备电流可构造标准曲线,采用机器智能学习算法分析、测算地铁供电系统中各类开关峰谷时段运行电流,以均值-方差方法确定电流的高度异常偏离点,实现异常点数据周期内统计以及实时提醒功能。应用电流实测值分析电流在工作日、节假日的不同曲线,为负荷预测和非正常运行方式下的负荷叠加风险提供预测和评估依据,保障供电系统的安全运行,提高负荷管控效率。     

A cost-competitiveness analysis of charging infrastructure for electric bus operations

This study investigates the cost competitiveness of different types of charging infrastructure, including charging stations, charging lanes (via charging-while-driving technologies) and battery swapping stations, in support of an electric public transit system. To this end, we first establish mathematical models to investigate the optimal deployment of various charging facilities along the transit line and determine the optimal size of the electric bus fleet, as well as their batteries, to minimize total infrastructure and fleet costs while guaranteeing service frequency and satisfying the charging needs of the transit system. We then conduct an empirical analysis utilizing available real-world data. The results suggest that: (1) the service frequency, circulation length, and operating speed of a transit system may have a great impact on the cost competitiveness of different charging infrastructure; (2) charging lanes enabled by currently available inductive wireless charging technology are cost competitive for most of the existing bus rapid transit corridors; (3) swapping stations can yield a lower total cost than charging lanes and charging stations for transit systems with high operating speed and low service frequency; (4) charging stations are cost competitive only for transit systems with very low service frequency and short circulation; and (5) the key to making charging lanes more competitive for transit systems with low service frequency and high operating speed is to reduce their unit-length construction cost or enhance their charging power.     

认知语境与英语学习中的主动倾听

认知语境是一种理论构架,是人头脑中固有知识的集合体.主动倾听是听者积极寻找话语含义的一种认知方法,通过分析认知语境对英语学习中主动倾听影响,对大学英语的科研改革带来一点启示.     

基于PLC的模糊频载调节器设计

介绍可编程序控制器(PLC)实现船舶电站模糊调频调载的软硬件实现方法,采用离线计算、在线查表的方法在PLC上实现模糊控制,利用硬件在环仿真进行试验研究,结果表明,智能频载控制器具有较好的稳、动态性能。     

乾元公司铁路专用线场站模式探讨

目前,传统的铁路专用线建设模式是铁路专用线自接轨站接轨,通过区间正线引入厂区的建设模式,这种模式的区间正线受地形条件、厂区位置和沿线规划影响较大,这些影响将不可避免地导致铁路专用线建设工程投资的增加,如能根据运输性质考虑缩短区间正线长度,在接轨站旁边设装车作业站,将大大减少专用线工程投资.以乾元公司铁路专用线建设模式为例来研究铁路专用线场站模式,就如何在接轨站旁边设装车作业站,实现接轨站设备与铁路专用线共用进行探讨.     

米思米软件在模具工业中应用的可行性分析

本文介绍了米思米软件的创立以及三大功能,分析了该软件的优越性,得出作为标准件的全球性软件,在企业中米思米软件可以缩短设计时间,提高采购部门的效率,最终缩短整个从设计到制作的时间;在教学中米思米软件可以提高学生学习兴趣,巩固理论知识,强化实践操作,其应用前景非常广阔。     

百色市农村客运站经营管理实践

农村客运站场网络是公路客运站场网络的重要组成部分,是发展农村客运、促进农村地区经济社会发展和城乡商品交流的重要平台.文章结合当前百色市农村客运站经营管理现状,分析经营管理中存在的问题,提出了相关的对策和措施.为规范当地农村客运市场秩序、加快农村客运网络建设、提高社会主义新农村建设水平提供参考.