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以DD6129K80客车为例,简要介绍玉柴国Ⅳ发动机SCR后处理系统原理及SCR系统在客车上的优化设计。 相似文献
173.
为减少铝合金下角料在熔炼过程中粉尘的排放,采用6道风压缩和水净化对熔炼产生的烟尘进行净化,对净化过的烟尘进行测量分析,林格曼黑度符合GB 13271—2001《锅炉大气污染物排放标准》要求。为了提高铝合金下角料的回收比例,降低用工成本,采用机械操作手段,用物理方法将铝渣和灰分离,使处理后的残铝由珠、粒变成铝片和铝块,便于熔炼回收且不变质,提高了回收率,降低了用工成本,增加了企业的收益。 相似文献
174.
Zhen Qian Feng Xiao H.M. Zhang 《Transportation Research Part A: Policy and Practice》2011,45(9):861-879
In this paper, we study the economics of parking provision for the morning commute, where all the parking lots are owned and operated by private operators. The parking capacity allocations, parking fees and access times are considered in a parking market. First we solve the parking market equilibrium without regulatory intervention, revealing four types of competitive equilibrium. Only one of the four types of equilibrium, however, is found to be stable and realistic, and under it each parking area is preferred by the commuters during certain time periods. Compared to the case without parking choice, provision of parking through a competitive market is able to reduce commuters’ travel cost and queuing delay, but it does not necessarily lead to the most desirable market outcome that minimizes social cost or commuter cost. This issue can be addressed through market regulations, such as price-ceiling, capacity-floor or capacity-ceiling, and a quantity tax/subsidy regulation. It is found that both price-ceiling and quantity tax/subsidy regulations can efficiently reduce both the system cost and commuter cost under certain conditions, and help ensure the stability of the parking market. Numerical examples are also provided to illustrate these findings and furthermore, how a price ceiling or a quantity tax/subsidy should be set in a parking market under realistic model parameters. 相似文献
175.
John K. Stanley David A. Hensher 《Transportation Research Part A: Policy and Practice》2011,45(10):1020-1030
Transport is Australia’s third largest and second fastest growing source of greenhouse gas (GHG) emissions. The road transport sector makes up 88% of total transport emissions and the projected emissions increase from 1990 to 2020 is 64%. Achieving prospective emission reduction targets will pose major challenges for the road transport sector. This paper investigates two targets for reducing Australian road transport greenhouse gas emissions, and what they might mean for the sector: emissions in 2020 being 20% below 2000 levels; and emissions in 2050 being 80% below 2000 levels. Six ways in which emissions might be reduced to achieve these targets are considered. The analysis suggests that major behavioural and technological changes will be required to deliver significant emission reductions, with very substantial reductions in vehicle emission intensity being absolutely vital to making major inroads in road transport GHG emissions. 相似文献
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我国车用汽油质量浅析 总被引:5,自引:0,他引:5
虽然供用燃料和车用燃料电池在继续发展,但是在2030年以前、汽油将仍然是汽车的主要燃料。为了满足经济增长的需要,在2010年我国将进口约1亿吨原油。我国有足够的炼油能力,生产汽油满足汽车工业发展的需要。从2000年7月1日起,我国禁止使用含铅汽油和研究法锌烷值低于90的低标号汽油。汽油新标准GB17930-1999的实施,标志着汽油质量在减少发动机排放的进程中取得了显著的进步。为了满足日益严格的环保要求,我国汽油质量还应进一步提高。 相似文献
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工况法外排放对车辆实际使用排放有较大的影响。在BN6V87QE电控燃油喷射汽油机的标定过程中,对循环外排放进行了试验研究。研究表明,循环外排放主要产生于冷起动和暖机过程、加速过程、高速大负荷阶段。采取在冷起动阶段不使用过小的空燃比,在加速过程中不使空燃比偏离理论空燃比时间过长,及在高速大负荷阶段空燃比不要过小等方法能有效地降低循环外排放。 相似文献