排序方式: 共有48条查询结果,搜索用时 31 毫秒
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用快速老化方法评价国产三效催化剂性能 总被引:1,自引:3,他引:1
我国自主研究开发的车用三效催化剂具有贵金属含量低和成本低的特点,但其性能指标特别是耐久性能否满足实用化要求的问题一直受到国内外汽车界的极大关注。 相似文献
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认证认可国际互认体系的发展 总被引:2,自引:0,他引:2
为了适应国际贸易发展的需要,减少国际贸易的技术壁垒,提高国际贸易的效率,降低国际贸易中的成本,方便和促进国际贸易的开展,合格评定领域的国际互队体系正在发挥越来越重要的作用。 相似文献
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肖建华 《交通世界(建养机械)》2010,(8)
随着我国改革开放和国民经济的迅速发展,作为主要交通基础设施之一的高速公路突飞猛进地发展,为了偿还建设资金,做好收取车辆通行费用,则是高速公路管理工作的一项重要内容. 相似文献
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肖建华 《交通世界(建养机械)》2010,(4)
十五以来,我国以高等级公路为主的国道主干线的全国联网,为公路运输发展创造了条件。政府对运输行业管理的加强,使运输结构不断趋向合理,是公路运输企业发展的又一契机。当前公路运输虽然仍然处于市场整合阶 相似文献
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肖建华 《上海交通大学学报(英文版)》2007,12(6):805-812
Eringen's and Trusedell's polar decomposition are formulated by explicit formulation of displacement field, based on Chen's additive decomposition of deformation gradient. Then the strain introduced by the multiplicative decomposition and the strain introduced by the additive decomposition are formulated explicitly with displacement gradient. This formulation clears the intrinsic contents of strains defined by taking the Eringen's and Trusedell's polar decomposition. After that, Chen's strain definition was introduced to show that the plastic deformation can be understood as the irreversible local average rotation. For initial isotropic simple elastic material, the research shows that path-dependent feature of classical plasticity theory is naturally expressed in Chen's strain definition. For rate-independent plasticity, the related deformation stress was discussed. The research shows that for isotropic hardening material the relation equation between the required geometric configuration and the corresponding loading field is explicitly formulated. Hence, for metal forming, this paper explicitly formulates the related fields by displacement field and invariant elastic constants. 相似文献