共查询到18条相似文献,搜索用时 31 毫秒
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<正> 随着社会主义市场经济体制的建立和加快经济改革步伐,我国的城市客车制造业有了很大的发展、并已生产出了专用的城市客车底盘,前景十分看好。但由于有较多的生产制造厂,市场竞争也是十分激烈的,客车制造厂若想使产品立于不败之地,保持其旺盛的发展趋势,那么如何把握产品的市场技术发展趋势,是值得引起城市客车制造业重视的一个关键问题。据有关资料分析,我国城市客车产品在 相似文献
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在考虑性价比时应与使用成本及维修成本相结合,这不单是经济意义上的比值,还应兼顾环保性及服务性等。必需采用新装备(如涡流缓速器)、新制造工艺(如低油耗、低排放发动机等)来提高性价比。 相似文献
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为了治理汽车尾气对环境的污染,全国有12个试点城市开展了“清洁汽车行动”,发展燃气汽车是其中工作之一。该文提出了发展液化天然气(LNG)城市客车的可行性及车辆产品系列化的规划建议;介绍了压缩天然气(CNG)储气瓶的选择和三种燃料供给的方式。 相似文献
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随着石油能源逐渐短缺和环境污染增加,迫切需要研究开发新能源公交客车。通过介绍这方面国际发展趋势和国内发展状况,认为发展混合动力汽车是首选。 相似文献
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介绍世博燃料电池客车系统的构成原理,整车参数、动力系统参数,以及技术特点,并分析燃料电池客车的应用现状及推广前景。 相似文献
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根据上海目前商业化示范运营的CNG公交客车和超级电容公交客车,与国产柴油公交客车和无轨电车的运行实际状况从车辆的环保性、可靠性及全生命周期综合经济成本等方面进行对比分析,并提出相关建议。 相似文献
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该文详细介绍了新能源公交车在世博会成功示范运行的基本情况。通过对新能源公交车线路投放情况、运营线路等阐述,为新能源公交车在今后的发展提供参考。 相似文献
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该文介绍了上海新能源公交车基本使用情况,从5个方面提出新能源汽车在推广应用中存在的现实问题,并对上海新能源公交车推广应用及发展提出相关建议。 相似文献
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"安全、稳定、经济、清洁的现代能源产业体系"为"十二五"时期增强能源供给能力、为经济社会稳定发展提供有力保障指明了目标和方向。本文在阐述现代能源产业体系的内涵及其特征的基础上,提出构建现代能源产业体系的具体路径:加强能源先进技术的研发和应用,加快能源自主创新;增强能源资源供给保障能力;形成合理的能源产业结构;积极发展新型电力;建立并完善现代能源市场体系;继续扩大能源国际合作等。 相似文献
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A series of sap flow (transpiration, TRP) and energy balance components measurements were carried out in a representative tree hedgerow of Fraxinus uhdei in Mexico City (19° 19' N, 99° 11' W, 2250 m ASL). Measurements of sap flow in the trunks of the trees was selected as an alternative tool instead of eddy covariance or Bowen ratio-energy balance methods in order to determine the energy balance components of the tree canopy. These measurements were made in October (end of the rainy season) and December (dry season) in 1997, from 8:00 to 17:00 LST. TRP showed a unimodal pattern during the day. Mean daily transpiration was higher at the end of the rainy season (1506 g m–2 d–1) than in the begining of the dry season (972 g m–2 d–1) with maxima rates of 0.075 and 0.046 g m–2 s–1, respectively. During the rainy season net radiation (QN) was mainly dissipated by latent (QE) and sensible (QH) heat, 60 and 34 %, respectively. Latent heat increased in the day up to 184 W m–2. QN was dissipated by QH and QE by 75 and 25%, respectively, and QH had a maximum hourly value of 298 W m–2 during the day (8:00-17:00 LST) in the dry season. Seasonal differences in QE and QH were probably due to differences of water availability. Heat storage of the tree hedgerow canopy was found to be a negligible component of the energy balance in both seasons. Actual transpiration of the system was always lower than transpiration at equilibrium. This was probably due to a low water availability in the substratum, a high atmospheric evaporative demand and an effective stomatal control. Because the tree hedgerow was completely surrounded by paved areas and wind was coming from a drier side, it is possible that transpiration rates were affected by advection probably supressing TRP. 相似文献
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介绍了美国对清洁公共汽车的对比试验与选择。其中NREL的试验和HCRA的试验开展了天然气公共汽车与柴油公共汽车在废气排放方面的对比试验,而NAVC的试验对象则是混合动力公共汽车、CNG公共汽车和使用低硫柴油的公共汽车。同时还介绍了纽约、波士顿、克利夫兰、洛杉矶对选择公共汽车清洁能源的不同做法。 相似文献
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介绍十堰二水厂在设计中本着节能、经济、先进的原则,选取制水、输配电等工艺方案及主要设备,从而为节约能耗、提高效率打下坚实的基础。 相似文献