地铁电动车组的VVVF逆变器控制系统

本文简述了交流传动系统应用于城市地铁交通的优越性，分析了主电路及控制电路的原理，并对其具体实现办法进行了初步探讨。     

Conformity: How VMT-speed distributions can affect mobile emission inventories

Transportation conformity is a US regulatory process that requires that transportation modeling be integrated with air quality modeling. Consequently, every change to either modeling process is undertaken with great scrutiny by the regional governments, who have to use the models for demonstrating conformity. This paper explores the "trip versus link debate," which stems from the fact that the standard travel demand models used by most metropolitan planning organizations are primarily link oriented, while the air quality models have been primarily trip oriented. Using the Sacramento region we examine the effects on mobile source emissions inventories when speed-VMT distributions are constructed using the trip and link-based philosophies. The results of our study indicate that trip-based VMT-speed distributions produce consistently lower emissions estimates than the link-based distributions. We use the results to assert that deciding between a trip-based or link-based conformity modeling process involves more than the technical difficulty of changesto the models or the potential political ramifications, it involves assessing which method will provide the most accurate estimates of regional motor vehicle emissions. We also examine ways to think about constructing mobile source emission inventories.     

基于物联网技术的新型空中交通管理系统

空中交通需求的快速增长推动了空管新理念和新技术的出现,应用新技术构建新型空管系统成为民航科研的热点.分析了空管技术发展趋势及其物联网技术基础,提出了基于物联网技术的新型空管系统,分析了其涵义与特征,给出了该新型空管系统的总体框架,主要包括感知层、基础设施网络层、应用服务平台层、专业应用与决策支持层.阐述了新型空管系统建设涉及的关键技术和支撑平台,以及新型空管系统的应用前景.     

地铁车厢内回风方式数值仿真分析

不同的空调回风方式对地铁车厢内的空调效果有一定的影响。文章采用数值方法对车厢内流场进行仿真,分析了两种常见的地铁车厢内回风方式的温度场和流场。结果表明,采用两种回风方式,均能满足乘客舒适性要求。     

断阶滑行艇喷气减阻机理研究

本文通过艇底流态显示、艇体运动姿态及阻力测量，研究了滑行艇艇底喷气对流场、阻力等的影响规律。断阶稍前处喷气引起总阻力和浸湿面积的大幅减少，喷气所减少的阻力成分为摩擦阻力，喷气对剩余阻力的影响甚微。     

可控式被动减摇水舱气道的阻尼

可控式被动减摇水舱的气道和阀口对减摇水舱内水的振荡起阻尼作用,对减摇水舱的减摇效果有负面影响.文章给出了气道(含阀口)产生的气压附加阻尼系数的计算方法,分析了气压附加阻尼对舱内水振荡特性及减摇效果的影响.     

含酚废水处理工艺综述

含酚废水是一种常见的工业废水，本文分别阐述了萃取、SBR、湿式氧化几种典型工艺处理含酚废水的试验情况，归纳出不同含酚废水合适的处理工艺。     

地铁列车过渡车钩功能改进及应用

针对目前内燃调车机车采用过渡车钩对地铁列车调车作业中存在的问题,提出了对过渡车钩的改进方案,以达到缓解地铁列车停放制动、提高调车效率的目的。同时提出了对地铁列车制动管路进行改进的思路,以实现内燃调车机车与地铁列车同步实施制动与缓解,从而大幅提高调车过程的安全性与效率。     

密闭空间空气净化用滤材检测设备设计研究

随着机动车辆的普及,人们呆在密闭空间即驾乘室以及室内的时间会逐渐拉长,如何有效的控制密闭空间的PM2.5浓度值值得我们去探讨和研究。通过对密闭空间空气净化原理的分析,采用激光粒子计数方法,设计了密闭空间空气净化检验流程及相配套的检测设备,将密闭空间(含室内及驾乘室)大气中的PM2.5含量控制在标准要求的浓度值以内。     

Origin–destination synthesis for aviation network data: examining hub operations in the domestic and international US markets

Hub‐and‐spoke networking is a key feature of current aviation markets in which hubs, as connecting points, function to consolidate and redistribute flows. This indicates that observation of traffic on a segment does not necessarily convey information about the origin to destination routing of passenger journeys because of the unavoidable detours in the system. This paper examines the heterogeneity of the flow composition in domestic and international US markets, which in turn allows us to observe the variation of operations across major hubs. A modified Route Flow Estimator for origin–destination synthesis (or origin–destination matrix estimation) is designed to decompose the segment traffic into itinerary‐based passenger trips. Several public and commercial databases, which are easily accessible, are exploited (and reconciled) for the model in order to (i) generate possible trip itineraries using those segment markets, and (ii) link data‐driven operational conditions with the underlying segment flows. The results are validated with US domestic trip observations and empirical knowledge related to the air transportation system. Then, the variability of the hub operations is examined based on sensitivity tests using the model parameters. From the resolution of itinerary‐based estimates, we observe that major airports' hub operations are spatially uneven, particularly with respect to domestic and international connecting passengers. Copyright © 2017 John Wiley & Sons, Ltd.