排序方式: 共有74条查询结果,搜索用时 15 毫秒
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卢文娟 《广州航海高等专科学校学报》2009,17(4):52-54
以输入假说为基础,通过对当前航海类专业英语教学的现状分析,提出弊端,并从其教材的选用、教学方法的改进等方面,探讨了该理论对航海类专业英语教学的启示,以此提高教学效果 相似文献
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H. Yang B. Kim Y. Park W. Lim S. Cha 《International Journal of Automotive Technology》2009,10(3):381-390
In recent studies, various types of multi-mode electric variable transmissions for hybrid electric vehicles have been proposed.
A multi-mode electric variable transmission consists of two or more different types of a planetary gear hybrid powertrain
system (PGHP), which can change power flow type using clutches to improve transmission efficiency. Input split systems are
generally used for the single-mode powertrain because of their overall superiority, but other power split systems such as
output split and compound split systems can be used in the dual-mode powertrain. In this study, we analyze the power transmission
characteristics of output split systems, and evaluate their fuel economies in the FTP72 cycle, acceleration performance, and
constant vehicle speeds. These results enable the selection of appropriate systems for a dual-mode powertrain. 相似文献
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基于响应面方法的车钩缓冲器特性曲线优化分析 总被引:1,自引:0,他引:1
为了更加真实地反映车钩缓冲器实际工作状态和进行缓冲器特性曲线优化,提出采用列车纵向动力学系统对缓冲器的特性曲线进行分析。在优化方面,从响应面方法的基本原理出发,建立响应面的子区域构造方法,运用凝聚函数和惩罚技术处理约束的遗传算法求解加约束条件的二次响应面最优解。以大秦线实际线路、列车编组以及列车纵向动力学性能为优化计算的条件,结合缓冲器数值模型建立缓冲器特性曲线的优化模型,运用所提出基于遗传算法的响应面方法对重载列车缓冲器特性曲线进行优化求解。结果说明所提方法对求解缓冲器特性曲线的优化问题非常有效。 相似文献
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Jan Owen Jansson 《Research in Transportation Economics》2008,22(1):179-187
Excellent public transport which makes the private car a minority mode of central-city travel is a necessary condition for a political process towards the introduction of congestion charges. However, the charging system costs in London and Stockholm have proved to be unexpectedly high. Therefore, before these costs come down to an affordable level, zero-fares for central-city travel and stricter parking policy would be a first-best combination in many cities, always provided that the public transport is really competitive. A bold venture in public transport development is consequently the top priority irrespective of the transport pricing policy direction. 相似文献
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根据半挂牵引车的特点,引入并修改了国外广泛应用的中间位置转向操纵稳定性试验方法,介绍了对试验结果的评价方法,并结合某国产牵引车和Scania360型牵引车进行了试验验证。通过试验发现,国产牵引车在路感、转向响应等方面都需进行改进;该试验方法在半挂牵引车操纵稳定性试验中应用是可行的。 相似文献
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介绍了ECU输出接口功率驱动电路的特点和工作原理。指出ECU输出接口故障一般是由于功率驱动器件损坏引起的。提出了通过ECU输出接口控制端找到相应功率驱动器件的方法;介绍了判断该常用功率驱动器件是否损坏的方法、代换原则以及对特殊封装的功率器件的识别和代换;给出了功率驱动器件更换后的试验方法。如果ECU故障是由输出接口故障引起的,则可以采用所介绍的方法维修而不必更换整个ECU,从而有效降低维修成本。 相似文献