美国天基预警卫星系统是导弹防御系统的重要组成部分,对其发展现状和能力的研究具有重要意义。为了支撑我国天基光学预警相关领域的基础研究和工程研制,在分析了美国国防支援计划(defense support program,DSP)和天基红外系统(space-bas...美国天基预警卫星系统是导弹防御系统的重要组成部分,对其发展现状和能力的研究具有重要意义。为了支撑我国天基光学预警相关领域的基础研究和工程研制,在分析了美国国防支援计划(defense support program,DSP)和天基红外系统(space-based infrared system,SBIRS)2代天基预警卫星的发展历程、系统构成以及主要问题的基础上,综述了美国“下一代过顶持续红外”(overhead persistent infrared,OPIR)预警卫星的若干研究进展和成果,详细总结了其在星座规划、传感器有效载荷研制、地面数据处理系统以及数据标准规范4个方面的研究现状,并建议从构建目标红外图像数据集、研制宽视场任务数据处理算法、发展搜索跟踪一体化大面阵载荷技术、加强卫星近场感知防御等方面给予重点研究。展开更多
Breaking waves can have tremendous destructive impact on vertical walls, yet they are poorly understood. By using particle imaging velocimetry （PIV） technology and high-precision pressure transducers, actual breakin...Breaking waves can have tremendous destructive impact on vertical walls, yet they are poorly understood. By using particle imaging velocimetry （PIV） technology and high-precision pressure transducers, actual breaking wave loads on vertical walls were studied. By simultaneously comparing the flow field structure and wave pressure, the mechanisms of breaking wave pressure could be analyzed. The probability distribution of the peak value of the first impact of a breaking wave was investigated. The results showed that the impact pressure p is mainly distributed in the range of 0.25-2.75 pv2, with the greatest possible probability at p/pv2 = 0.75.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.50679008
文摘Breaking waves can have tremendous destructive impact on vertical walls, yet they are poorly understood. By using particle imaging velocimetry （PIV） technology and high-precision pressure transducers, actual breaking wave loads on vertical walls were studied. By simultaneously comparing the flow field structure and wave pressure, the mechanisms of breaking wave pressure could be analyzed. The probability distribution of the peak value of the first impact of a breaking wave was investigated. The results showed that the impact pressure p is mainly distributed in the range of 0.25-2.75 pv2, with the greatest possible probability at p/pv2 = 0.75.
