Power Electronic (PE) will play an essential role in future drive concepts. Nowadays, mainly water/glycol-based cooling media are used to cool PE. Due to their high electrical conductivity (EC), water/glycol-based coo...Power Electronic (PE) will play an essential role in future drive concepts. Nowadays, mainly water/glycol-based cooling media are used to cool PE. Due to their high electrical conductivity (EC), water/glycol-based coolants cannot be used for direct cooling of the electrical components. Direct cooling concepts with dedicated transmission fluids show potential usage of fluid in direct contact with electrified parts. This results in special requirements for the fluids and materials. The aimed action as a coolant requires a defined measurement and characterization of fluid properties and heat transfer in order to assess the cooling ability of a fluid. The purpose of the work was to develop a new measurement setup based on the thermal transient method with which the thermal requirements of cooling fluids for a direct cooling concept can be assessed. With this method, relevant transmission fluids have been tested and the thermal performance compared to indirect cooling effect of water/glycol is discussed. The result of the work is that the measurement method is very well suited for the application-related evaluation of the fluids. Direct oil cooling with transmission fluids could increase heat transfer coefficient by a factor of 3 to 8, compared to the indirect cooing with water/glycol as cooling media.展开更多
以联合直接攻击弹药(Joint Direct Attack Munition,简称JDAM)为线索,介绍精确制导武器的发展过程,描述了JDAM精确打击流程,对JDAM开发中的关键技术:任务规划、捷联惯导、传递对准、组合导航等进行研究和分析,为我国精确制导武器的研制...以联合直接攻击弹药(Joint Direct Attack Munition,简称JDAM)为线索,介绍精确制导武器的发展过程,描述了JDAM精确打击流程,对JDAM开发中的关键技术:任务规划、捷联惯导、传递对准、组合导航等进行研究和分析,为我国精确制导武器的研制提供了一种发展模式和借鉴经验。展开更多
知识生产模式转型与“双一流”建设背景下,跨学科研究平台注重自身对国家、区域发展和经济社会进步的实际贡献成为其谋求可持续发展的应然使命。但我国的跨学科研究平台整体发展时间较短,在开展社会服务时存在动力欠缺、广度与深度有限...知识生产模式转型与“双一流”建设背景下,跨学科研究平台注重自身对国家、区域发展和经济社会进步的实际贡献成为其谋求可持续发展的应然使命。但我国的跨学科研究平台整体发展时间较短,在开展社会服务时存在动力欠缺、广度与深度有限、松散不成体系、相关制度安排与运行机制不完善等现实困境,在理念及目标设定、路径选择以及成果认定等方面亟待变革。基于美国脑、心智和机器中心(Center for Brain,Minds and Machines,CBMM)的案例,研究发现CBMM服务经济社会的逻辑动因在于寻求组织合法性、实现组织可持续发展,并同时实现增加弱势个体人力资本、促进向上社会流动与引领社会进步、助推社会生态更新的重要功能。CBMM得以兼顾组织发展和担当社会责任的关键在于凝聚社会公益共识、为弱势学生提供体系化的教育推广计划、借助知识转移构建创新集群、重构评价管理规范等创新举措,这为我国跨学科研究平台服务经济社会提供了可资借鉴的经验。展开更多
文摘Power Electronic (PE) will play an essential role in future drive concepts. Nowadays, mainly water/glycol-based cooling media are used to cool PE. Due to their high electrical conductivity (EC), water/glycol-based coolants cannot be used for direct cooling of the electrical components. Direct cooling concepts with dedicated transmission fluids show potential usage of fluid in direct contact with electrified parts. This results in special requirements for the fluids and materials. The aimed action as a coolant requires a defined measurement and characterization of fluid properties and heat transfer in order to assess the cooling ability of a fluid. The purpose of the work was to develop a new measurement setup based on the thermal transient method with which the thermal requirements of cooling fluids for a direct cooling concept can be assessed. With this method, relevant transmission fluids have been tested and the thermal performance compared to indirect cooling effect of water/glycol is discussed. The result of the work is that the measurement method is very well suited for the application-related evaluation of the fluids. Direct oil cooling with transmission fluids could increase heat transfer coefficient by a factor of 3 to 8, compared to the indirect cooing with water/glycol as cooling media.
文摘知识生产模式转型与“双一流”建设背景下,跨学科研究平台注重自身对国家、区域发展和经济社会进步的实际贡献成为其谋求可持续发展的应然使命。但我国的跨学科研究平台整体发展时间较短,在开展社会服务时存在动力欠缺、广度与深度有限、松散不成体系、相关制度安排与运行机制不完善等现实困境,在理念及目标设定、路径选择以及成果认定等方面亟待变革。基于美国脑、心智和机器中心(Center for Brain,Minds and Machines,CBMM)的案例,研究发现CBMM服务经济社会的逻辑动因在于寻求组织合法性、实现组织可持续发展,并同时实现增加弱势个体人力资本、促进向上社会流动与引领社会进步、助推社会生态更新的重要功能。CBMM得以兼顾组织发展和担当社会责任的关键在于凝聚社会公益共识、为弱势学生提供体系化的教育推广计划、借助知识转移构建创新集群、重构评价管理规范等创新举措,这为我国跨学科研究平台服务经济社会提供了可资借鉴的经验。
