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余明 《北京师范大学学报(自然科学版)》2005,41(3):312-314
阐明了流星雨的成因并介绍了流星雨的观测方法和实践,以及它的研究意义,对天文教育与科普工作者值得参考. 相似文献
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空间碎片防护结构效能评价仿真系统和应用 总被引:2,自引:2,他引:0
论述了流星体/空间碎片(M/OD)防护的重要性,给出了自主开发的空间碎片防护结构效能评价仿真平台总体框架.通过分析不同防护参数及碰撞参数条件下的防护结构效能,总结了防护间距、防护屏厚度、碰撞速度和碰撞角等参数对空间碎片防护结构效能的影响规律.针对基本的Whipple防护结构,碰撞速度V<3 km/s时,防护结构的防护效能不受防护间距变化的影响,碰撞速度v>3 km/s时.防护间距越大.防护结构的防护效能越好;Whipple防护结构的防护屏厚度越大.防护结构抗空间碎片撞击的能力越强.即其防护效能越好;在整个碰撞速度范围内(0~15 km/s),防护结构的防护效能呈现出3种不同的变化趋势,且防护结构的防护效能随碰撞角增大而提高.提出了一种波纹填充式防护结构,确定了可有效防护小尺寸空间碎片的防护设计参数. 相似文献
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Neutron capture effects and pre-atmospheric sizes of meteoroids 总被引:1,自引:0,他引:1
WANG Daode & LIN Yangting Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Correspondence should be addressed to Wang Daode 《科学通报(英文版)》2003,48(20):2236-2240
In 1963, Eberhardt et al.[1] found that there was a gap in cosmic-ray exposure (CRE) ages between stony and iron meteorites. CRE ages of most stony meteorites are ~10 Ma, and those of iron meteorites are 100 Ma. In order to explain this difference, Fireman and De Felice[2] introduced a concept of space erosion. These authors suggested that the space erosion of stony meteorites by dust particles was more intense than that of irons, because the former were fragile. However, this interpretat… 相似文献
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