In this paper, we propose multi-fin FET design techniques targeted for RF applications. Overlap and underlap design configuration in a base FinFET are compared first and then multi-fin device (consisting of transistor...In this paper, we propose multi-fin FET design techniques targeted for RF applications. Overlap and underlap design configuration in a base FinFET are compared first and then multi-fin device (consisting of transistor unit up to 50) is studied to develop design limitations and to evaluate their effects on the device performance. We have also investigated the impact of the number of fins (up to 50) in multi-fin structure and resulting RF parameters. Our results show that as the number of fin increases, underlap design compromises RF performance and short channel effects. The results provide technical understanding that is necessary to realize new opportunities for RF and analog mixed-signal design with nanoscale FinFETs.展开更多
Mathematical model of cross type multi-stream plate-fin heat exchanger is established.Meanwhile,mean square error of accumulative heat load is normalized by dimensionless,and the equations of temperature-difference un...Mathematical model of cross type multi-stream plate-fin heat exchanger is established.Meanwhile,mean square error of accumulative heat load is normalized by dimensionless,and the equations of temperature-difference uniformity factor are improved.Evaluation factors above and performance of heat exchanger are compared and analyzed by taking aircraft three-stream condenser as an example.The results demonstrate that the mean square error of accumulative heat load is common result of total heat load and excess heat load between passages.So it can be influenced by passage arrangement,flow inlet parameters as well as flow patterns.Dimensionless parameter of mean square error of accumulative heat load can reflect the influence of passage arrangement to heat exchange performance and will not change dramatically with the variation of flow inlet parameters and flow patterns.Temperature-difference uniformity factor is influenced by passage arrangement and flow patterns.It remains basically unchanged under a certain range of flow inlet parameters.展开更多
The ultimate goal of weapon system employing an explosively formed penetrator(EFP) is to defeat a target at the longest standoff.In order to do this,an EFP must be aerodynamically stable so as to strike the target at ...The ultimate goal of weapon system employing an explosively formed penetrator(EFP) is to defeat a target at the longest standoff.In order to do this,an EFP must be aerodynamically stable so as to strike the target at a small angle of obliquity,and the decay velocity per meter of EFP must be smaller at extended standoff.As the angle of attack increases,the penetration ability of EFP greatly reduces.The fins improve the EFP aeroballistic characteristics and decrease the flight drag of EFP as well.EFP with fins formed by three-point initiation is presented.The formation of EFP with fins is studied by LS-DYNA,and the aeroballistics is studied through experiment.The experimental results show that the decay velocity per meter of EFP with fins is much smaller than that of normal EFP.and the attitude angle steadily decreases.展开更多
文摘In this paper, we propose multi-fin FET design techniques targeted for RF applications. Overlap and underlap design configuration in a base FinFET are compared first and then multi-fin device (consisting of transistor unit up to 50) is studied to develop design limitations and to evaluate their effects on the device performance. We have also investigated the impact of the number of fins (up to 50) in multi-fin structure and resulting RF parameters. Our results show that as the number of fin increases, underlap design compromises RF performance and short channel effects. The results provide technical understanding that is necessary to realize new opportunities for RF and analog mixed-signal design with nanoscale FinFETs.
文摘Mathematical model of cross type multi-stream plate-fin heat exchanger is established.Meanwhile,mean square error of accumulative heat load is normalized by dimensionless,and the equations of temperature-difference uniformity factor are improved.Evaluation factors above and performance of heat exchanger are compared and analyzed by taking aircraft three-stream condenser as an example.The results demonstrate that the mean square error of accumulative heat load is common result of total heat load and excess heat load between passages.So it can be influenced by passage arrangement,flow inlet parameters as well as flow patterns.Dimensionless parameter of mean square error of accumulative heat load can reflect the influence of passage arrangement to heat exchange performance and will not change dramatically with the variation of flow inlet parameters and flow patterns.Temperature-difference uniformity factor is influenced by passage arrangement and flow patterns.It remains basically unchanged under a certain range of flow inlet parameters.
文摘The ultimate goal of weapon system employing an explosively formed penetrator(EFP) is to defeat a target at the longest standoff.In order to do this,an EFP must be aerodynamically stable so as to strike the target at a small angle of obliquity,and the decay velocity per meter of EFP must be smaller at extended standoff.As the angle of attack increases,the penetration ability of EFP greatly reduces.The fins improve the EFP aeroballistic characteristics and decrease the flight drag of EFP as well.EFP with fins formed by three-point initiation is presented.The formation of EFP with fins is studied by LS-DYNA,and the aeroballistics is studied through experiment.The experimental results show that the decay velocity per meter of EFP with fins is much smaller than that of normal EFP.and the attitude angle steadily decreases.
基金Projects （50436010, 50375055） supported by the National Natural Science Foundation of China Project （04105942） supported by the Natural Science Foundation of Guangdong Province, China
