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21.
2009年,我国首次成为世界汽车产销第一大国,机动车尾气排放造成的污染耳益严重,已成为我国大中城市空气污染的主要来源。文章介绍了机动车尾气污染的危害,并提出了针对性的控制措施。 相似文献
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从气隙磁场磁势分布情况可知,单相异步电动机的振动转矩客观存在.为了能更好地降低其振动转矩,提出了把两台参数相同的单相异步电动机采用同轴连接运行的方法.当两台电机定子磁场互差90°电角度时,由椭圆磁场产生的振动转矩将基本被相互抵消.实验证明,该方法能有效降低单相异步电动机的转动转矩. 相似文献
24.
陈大力 《黄石理工学院学报》2010,26(2):1-4,8
以4 200kW交-交变频同步电动机控制主回路工程为例,介绍了主回路线路图,并根据同步电动机的技术参数进行了主回路的参数计算,给出了主整流变压器、晶闸管、励磁变压器以及励磁晶闸管的参数选择方法,为国内其他钢铁企业大型主传动电机改造提供了参考。 相似文献
25.
黄新明 《黄石理工学院学报》2013,(5)
应用绿色机械加工理念,对叶片式气动马达定子的制作方式进行了改进与优化。在不同情况下,通过对铸铁、铸钢和厚壁无缝钢管等不同材料和形式定子毛坯的选用,不仅大幅提高了材料的利用率,而且最大限度地降低了定子的生产成本。 相似文献
26.
This paper addresses the problem of designing a household waste collection system for rural insular areas using a barge for transportation, based on a novel mixed integer programming model that simultaneously integrates decisions of waste collection sites selection within the islands to be served, visit schedule for each selected collection site, and multi-period vehicle routing. An application to a real-world instance consisting of small rural islands located in the south of Chile shows the effectiveness and complexity of the model, along with the advantages of using a waste compactor instead of transporting the waste using bins onboard a barge. 相似文献
27.
Recent Chinese economic and energy policies recognize the transportation sector as a key element in the nation's effort to meet its energy and air quality goals. The development of alternative fuel vehicle (AFV) has been considered as a particularly promising strategy. AFV-related policies can be traced back to the eighth Five-Year Plan period (i.e., 1991-1995). All the work during the last twenty years has cumulatively prompted the transition of AFV development from policy-making to actual implementation and from research and development (R&D) to mass production. The year of 2009 is significant for the AFV industry in China in that the central government announced the “Plan on Shaping and Revitalizing the Auto Industry”. This Plan launched a demonstration program of electric vehicle (EV) deployment in 13 Chinese cities and set the national goal of manufacturing 0.5 million AFVs in three years. To better understand the current status, problems and uncertainties existed in the EV deployment in China, this paper reviewed the relevant policies and reported a survey with the pilot cities during the summer of 2009. Based on the survey findings, this paper developed a number of recommendations to help address the issues found in the demonstration program to date. 相似文献
28.
Jaehyun So Nassim Motamedidehkordi Yingjie Wu Fritz Busch Keechoo Choi 《International Journal of Sustainable Transportation》2018,12(4):286-298
This study proposes an integrated simulation approach, which consists of a microscopic traffic simulation model, a vehicle dynamics model, and an emission estimation model, in order to estimate emissions based on more reliable vehicle performance measures. The vehicle performance measures such as engine power and engine speed significantly relate to the amount of emissions, and road curvatures and inclinations are the core inputs affecting these vehicle performance measures. Therefore, providing reliable vehicle performance measures reflecting the road geometric attributes is critical for a reliable emission estimation. This study proposes to use the microscopic traffic simulation model for generating vehicle trajectories, which is advantageous in modeling various traffic situations, and the vehicle dynamics model for producing the vehicle performance measures based on the vehicle trajectories. Finally, the outputs from the vehicle dynamics model are fed into the emission estimation model to compute emission measures. This study conducted a case-study using two road sections, one is a hypothesized road section, including various curvatures and inclinations with regular variations, and the other is a Kesselberg road section, which is an actual geometry in Bayern, Germany. The emission measures are estimated in these case-study road sections using both an existing simulation approach and the proposed integrated simulation approach. The difference between these two emission estimation approaches is discussed in terms of the emission measures, including fuel consumption, nitrogen oxides, and particulate matters. 相似文献
29.
Neo-tribes have been defined as including people from different walks of life who come together in fluid groupings, bound by common interests, similar lifestyles, rituals and language. This concept is popular in sociological literature, but has rarely been applied to travellers or tourism literature. This study sought to understand whether neo-tribalism could add insights into our existing knowledge of recreational vehicle (RV) users in Canada. Using a grounded theory approach including focus groups and in-depth interviews, the research found RV users exhibit neo-tribal characteristics which can be characterised as symbolic and behavioural. The behavioural aspects of this neo-tribe are evident in campsites, where rituals such as happy hours exist. Symbolic aspects included fluidity of membership and commitment to the RVing lifestyle. The findings suggest that the neo-tribal concept is a highly useful tool for understanding the motivations, behaviour and needs of travellers and adds new insights into our understanding of the RVing experience. 相似文献
30.
Reinhard Sellmair Tom Schelo 《International Journal of Sustainable Transportation》2019,13(7):479-496
Replacing conventional vehicle taxis with electric vehicles would be an efficient measure to reduce greenhouse gas emissions. Due to the limited range and long charging times of current battery electric vehicles, it is of utmost importance to provide sufficient charging facilities. This article analyses the impact of the placement and charging power of charging stations on potential mileage and revenue of electric taxis on the example of Singapore. Therefore, we developed an agent-based electric taxi simulation model to investigate electric taxis’ driving profiles with respect to different vehicle types and charging infrastructure designs. This model is also capable of simulating conventional taxi driving profiles. The validation of these simulation results with real taxi data showed that the model is reproducing taxi driving profiles with high accuracy in great detail. We found out that electric taxis could reach the same mileage and revenue as conventional taxis if charging with a power of 160?kW is possible. Furthermore, we discovered that waiting times for available charging stations have a stronger effect on revenue than the length of detours to reach charging stations. Based on these findings, we concluded that it is more important to reduce waiting times by placing sufficient numbers of charging stations at each location before expanding the charging network by installing small numbers of charging stations at many locations. 相似文献