排序方式: 共有438条查询结果,搜索用时 203 毫秒
121.
122.
123.
124.
125.
126.
Yunlong Zhang Jinpeng Lv Qi Ying 《Transportation Research Part D: Transport and Environment》2010,15(8):497-502
This paper presents a methodology of assigning traffic in a network with the consideration of air quality. Traffic assignment is formulated as an optimization problem considering travel cost and on-road emissions. It introduces a cell-based approach to model emission concentrations so that either the average or maximum emissions in a network can be considered in the optimization process. The emissions in a cell are modeled taking into consideration the influence of the emission sources from all cells in the network. A case study demonstrates that minimizing travel cost and reducing air pollutants may not be always achieved simultaneously. The traffic assignment procedure can effectively reduce emission concentrations at those locations with the worst air quality conditions, with only a marginal increase in travel time and average emission concentration in the network. 相似文献
127.
外向型经济飞速发展的中国,不仅是世界第三大汽车市场,而且也将是国际汽车贸易的主要输出国。作为汽车制造业的战略选择,中国汽车出口所遇到的问题,还不仅仅在于汽车产业自身的竞争力,也在于外销过程中的运力短缺。技术并不尖端的汽车滚装船,为啥舱位难求,为啥价高如许?同样是整机出口的机电产品,船舶咋就不能拉汽车兄弟一把? 相似文献
128.
129.
吕有界 《广州航海高等专科学校学报》2001,(2):32-35
针对在AutoCAD中表面粗糙度的标注过程相对较繁这一问题,实现表面粗糙度自动标注对于提高绘图效率,从而提高生产率,有一定的现实意义。利用AutoLISP语言进行程序设计,运行结果表明,效果良好。 相似文献
130.
通过对南京地铁1号线电动车制动电阻箱常见故障进行统计,分析了主要故障发生的原因,并在此基础上提出了改进措施。 相似文献