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21.
随着高职教育的发展,建立"基于工作过程"的案例模拟模式已成为探索和深化商务外事英语课程建设的重要任务。本文从提高高职学生商务外事英语应用能力的需求出发,探索了基于工作过程的案例模拟模式,为培养并提高学生商务外事英语的应用能力提供了新的思路。  相似文献   
22.
黎宇科 《天津汽车》2010,(12):17-18
为促进报废汽车环保回收,提高资源循环利用率,文章基于对我国汽车市场和报废汽车回收拆解行业的现状分析,从政策措施层面提出提高报废汽车回收行业水平的方案设想.认为首先应选择全国废旧汽车资源集中的3个地区建立报废汽车破碎示范中心,其次要支持现有拆解企业升级改造,最后要完善相关管理制度.  相似文献   
23.
2001年我国启动了"863"计划电动汽车重大专项,我国新能源汽车产业开局良好。自2004年起,在国家的长远规划和能源政策中,新能源汽车产业和技术的发展被多次强调。2009年是我国新能源汽车产业破局之年,诸多鼓励政策相继出台。2010年我国新能源汽车扶持新政策或将出台。最后提出以财税金融激励手段推进我国新能源汽车发展。  相似文献   
24.
机场救援消防车底盘系统研究   总被引:1,自引:0,他引:1  
机场救援消防车底盘系统因特殊的使用要求,使其性能及技术应用达到了重型越野汽车技术的最高水平。随着我国重型越野车辆研究、制造水平的提高,我国已经在此领域进行了一些研究和试验。本文通过对机场救援消防车底盘系统的性能、国内外现有技术水平和未来发展趋势等几个方面的阐述对机场救援消防车底盘系统进行了较为全面的分析。  相似文献   
25.
文章基于有限元法,采用Nastran软件,对某商用车驾驶室系统进行了CAE模态,弯曲扭转刚度和强度分析,结果显示,驾驶室前四阶模态有效避开了发动机怠速频率,而弯曲和扭转刚度满足设计目标,同时,驾驶室四工况下最大塑性应变达成设计目标,综合评估该商用车驾驶室力学性能符合设计要求.  相似文献   
26.
Commercial passenger cars are a possible early market segment for plug-in electric vehicles (PEVs). Compared to privately owned vehicles, the commercial vehicle segment is characterized by higher mileage and a higher share of vehicle sales in Germany. To this point, there are only few studies which analyze the commercial passenger car sector and arrive at contradictory results due to insufficient driving profile data with an observation period of only one day. Here, we calculate the market potential of PEVs for the German commercial passenger car sector by determining the technical and economical potential for PEVs in 2020 from multi-day driving profiles. We find that commercial vehicles are better suited for PEVs than private ones since they show higher average annual mileage and drive more regularly. About 87% of the analyzed three-week vehicle profiles can technically be fulfilled by battery electric vehicles (BEVs) with an electric driving range of about 110 km while plug-in hybrid electric vehicles (PHEVs) with an electric range of 40 km could obtain an electric driving share of 60% on average. In moderate energy price scenarios, PEVs can reach a market share of 2–4% in the German commercial passenger car sales by 2020 and especially the large commercial branches (Trade, Manufacturing, Administrative services and Other services) are important. However, our analysis shows a high sensitivity of results to energy and battery prices as well as electric consumptions.  相似文献   
27.
通过研究物联网技术、车联网技术及空天车地一体化网络的理论和应用现状,分析列车群车联网系统构建需求,搭建基于空天车地一体化列车群车联网系统总体框架;分别建立艇载、机载、车载、区域监测和地面中心监测节点和网关,阐述系统的通信结构;提出基于空天车地一体化的列车群车联网系统物理架构设计及信息传输等关键问题。为进一步研究服务于列车群监测和通信的空天车地一体化网络的理论和应用研究起到指导和启发作用。  相似文献   
28.
为了解决环保问题,增强底盘耐老化、耐蚀性,开发一种适合商用车底盘的水性防护蜡是一个较好的方向和措施。本文主要从机理、性能标准和实验检测、施工工艺和设备等方面介绍了水性蜡。水性蜡各项性能满足技术标准和施工要求,具有很大的优势和发展潜力。  相似文献   
29.
Due to frequent stop-and-go operation and long idling periods when driving in congested urban areas, the electrification of commercial delivery trucks has become an interesting topic nationwide. In this study, environmental impacts of various alternative delivery trucks including battery electric, diesel, diesel-electric hybrid, and compressed natural gas trucks are analyzed. A novel life cycle assessment method, an environmentally-extended multi-region input-output analysis, is utilized to calculate energy and carbon footprints throughout the supply chain of alternative delivery trucks. The uncertainties due to fuel consumption or other key parameter variations in real life, data ranges are taken into consideration using a Monte Carlo simulation. Furthermore, variations in regional electricity mix greenhouse gas emission are also considered to present a region-specific assessment for each vehicle type. According to the analysis results, although the battery electric delivery trucks have zero tailpipe emission, electric trucks are not expected to have lower environmental impacts compared to other alternatives. On average, the electric trucks have slightly more greenhouse emissions and energy consumption than those of other trucks. The regional analysis also indicates that the percentage of cleaner power sources in the electricity mix plays an important role in the life cycle greenhouse gas emission impacts of electric trucks.  相似文献   
30.
Patterns of traffic activity, including changes in the volume and speed of vehicles, vary over time and across urban areas and can substantially affect vehicle emissions of air pollutants. Time-resolved activity at the street scale typically is derived using temporal allocation factors (TAFs) that allow the development of emissions inventories needed to predict concentrations of traffic-related air pollutants. This study examines the spatial and temporal variation of TAFs, and characterizes prediction errors resulting from their use. Methods are presented to estimate TAFs and their spatial and temporal variability and used to analyze total, commercial and non-commercial traffic in the Detroit, Michigan, U.S. metropolitan area. The variability of total volume estimates, quantified by the coefficient of variation (COV) representing the percentage departure from expected hourly volume, was 21%, 33%, 24% and 33% for weekdays, Saturdays, Sundays and holidays, respectively. Prediction errors mostly resulted from hour-to-hour variability on weekdays and Saturdays, and from day-to-day variability on Sundays and holidays. Spatial variability was limited across the study roads, most of which were large freeways. Commercial traffic had different temporal patterns and greater variability than non-commercial vehicle traffic, e.g., the weekday variability of hourly commercial volume was 28%. The results indicate that TAFs for a metropolitan region can provide reasonably accurate estimates of hourly vehicle volume on major roads. While vehicle volume is only one of many factors that govern on-road emission rates, air quality analyses would be strengthened by incorporating information regarding the uncertainty and variability of traffic activity.  相似文献   
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