重载组合货运列车空气制动技术

分析重载组合货运列车空气制动存在的问题及要求,介绍国际上重载组合列车使用的ECP系统和LOCOTROL系统;重点阐述采用LOCOTROL系统组合列车的机车制动机均衡风缸开、闭环控制模式特点以及大秦铁路组合重载试验情况。     

基于CFD的某型船用柴油发电机组隔声罩内通风换热计算分析

本文基于某型船用柴油发电机组隔声罩内热源分析进行罩内空气冷却装置初步设计,应用FLUENT对隔声罩内温度场、流场进行计算分析,基于计算优化冷却装置布置。经样机试验实测,罩内温度分布与计算结果基本一致,各测点温度未超出罩内温度限值,保证机组安全可靠运行。     

Integrated Evaluation of Air Traffic Controller Workload Based on Matter-Element Analysis

A model for evaluating the controller workload was presented based on matter-element analysis, particularly from a man-machine-environment system engineering perspective. On the basis of a questionnaire survey, 18 kinds of indexes which influence the controller workload were determined. By establishing the classical field and node field of the controller workload, the correlation function of the controller workload grade was obtained; then the correlation degree and estimated grade of controller workload were given. A case study verifies the feasibility of the proposed evaluation method.     

扩容空中交通管理研究

随着全球空中交通流量以前所未有的速度在递增,我国的空中交通管理的管理体制、应用技术以及管理理念已经越来越不能满足空中交通发展的需求。本文首先介绍了“扩容空中交通管理”这个新概念,然后结合我国现行的空中交通管理现状,将扩容空中交通管理与现行空中交通管理进行了全面对比,然后,结合我国空中交通管理特有的运行环境以及未来空中交通管理的发展趋势,提出我国空中交通管理应该由分散向集中统一管理转变;管理中的流量管理子模块将实行战略、预战术、战术三个阶段的协同流量管理;最后实现“空天地”一体化管理。     

航路网络系统结构稳定性研究

航路网络系统的结构稳定性直接影响空中交通流量管理实施的有效性。本文考虑空中交通流与道路交通流的共性,借鉴堵塞流理论对航路网络系统进行稳定性分析,并提出了衡量系统稳定性的指标和提高航路网络结构稳定性的措施。通过对典型的航路网络结构进行仿真计算,验证了提高稳定性措施的正确性和可行性,说明了航路稳定性研究能为空中交通流量管理提供技术和决策支持。     

蚁群算法在解决空中交通飞行冲突中的应用

本文主要研究了蚁群算法在解决空中交通冲突问题中的应用。首先对空中交通冲突解决问题的研究背景以及研究现状进行了系统的概述,随后建立了相关的数学模型,将空中交通飞行冲突问题转化为有约束的非线性整数规划问题,并设计了基于蚁群算法的求解思路。最后的仿真计算证明该方法在较短时间内能提供多种不同的有效的冲突解决方案。     

宇通客车气压ABS原理及检测

介绍宇通客车气压ABS的组成,每个元件的功能、测试方法以及ABS的闪码诊断程序和故障码含义.     

Determinants of the willingness-to-pay for reducing the environmental impacts of road transportation

This paper examines the willingness-to-pay of people living in a number of villages in Navarre, in the Spanish Pyrenees to reduce noise and air pollution. Several models are used for estimation based on contingent valuation, noting that those living near roads are willing to pay more to reduce air and noise pollution. In addition, younger people, the better educated, and the more environmentally aware individuals are also willing to pay more to reduce those externalities.     

基于HyperWorks的汽车空气滤清器模态分析

乘用车空气滤清器的固有频率是一个重要的性能指标,需要满足特定的设计目标值。文章运用HyperWorks软件对某乘用车空气滤清器建立有限元模型,进行模态分析,获得固有频率,根据分析结果,提出改进措施,并对改进后的空气滤清器进行分析,确保其满足设计指标要求。     

The impacts of inter-vehicle spacing on in-vehicle air pollution concentrations in idling urban traffic conditions

The influence of inter-vehicle spacing on the in-vehicle air pollution exposure of car commuters in heavy traffic conditions was investigated, both experimentally and numerically. An experimental investigation was carried out into the effect, on in-vehicle air pollution exposure, of maintaining a distance of approximately 2 m to the preceding vehicle in congested idling traffic conditions compared to that of an identical vehicle maintaining a distance of approximately 1 m. In-vehicle VOC and PM_2.5 concentrations revealed that a 19–31% reduction in exposure at the larger inter-vehicle spacing. A computational fluid dynamics model was calibrated using the experimental data and used to prediction car exposure under different conditions by varying certain key parameters. Agreement between the experimental and predicted data of 82% was achieved. The results show a significant drop in pollutant concentrations occurred within the first 2 m of their emission from the preceding vehicles exhaust.