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排序方式: 共有425条查询结果,搜索用时 15 毫秒
421.
Giovanni Gobbo 《Space Policy》1991,7(1)
In this article the author assesses trends in the major parameters governing space insurance over the past decade. Following the series of launch failures in the mid-1980s premium rates rose sharply, and they have generally remained high — too high, clients sometimes feel. Yet the insurers' financial balance remains consistently negative. The industry leaders can now perhaps bring stability to premium rates, and the climate could be further improved if policies more clearly defined responsibilities and liabilities. However, clients must beware of destroying the space industry market by taking advantage of its momentary weaknesses. 相似文献
422.
An experimental method capable of directly measuring the net radiant heat flux on complex geometry surfaces by non invasive methods has been devised, designed, realized and tested. The method is based on a computerized thermographic system capable of directly outputting the radiative heat fluxes absorbed by the surface to be examined. The calibration tests have shown the feasibility and the accuracy of the proposed method. Preliminary tests are presented which simulate the radiation flux from a jet exhaust. 相似文献
423.
Giovanni F. Bignami 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(4):15-21
The current knowledge on celestial high-energy gamma-ray sources is reviewed on the occasion of the end of the COS-B satellite. The breakthroughs of such a mission are outlined together with its limitations. Future experimental possibilities are presented in the context of planned missions. 相似文献
424.
Alisson Dal Lago Walter D. Gonzalez Aline De Lucas Carlos Roberto Braga Lucas Ramos Vieira Tardelli Ronan Coelho Stekel Marlos Rockenbach 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
In this work, we present a study of the coronal mass ejection (CME) dynamics using LASCO coronagraph observations combined with in-situ ACE plasma and magnetic field data, covering a continuous period of time from January 1997 to April 2001, complemented by few extreme events observed in 2001 and 2003. We show, for the first time, that the CME expansion speed correlates very well with the travel time to 1 AU of the interplanetary ejecta (or ICMEs) associated with the CMEs, as well as with their preceding shocks. The events analyzed in this work are a subset of the events studied in Schwenn et al. (2005), from which only the CMEs associated with interplanetary ejecta (ICMEs) were selected. Three models to predict CME travel time to Earth, two proposed by Gopalswamy et al. (2001) and one by Schwenn et al. (2005), were used to characterize the dynamical behavior of this set of events. Extreme events occurred in 2001 and 2003 were used to test the prediction capability of the models regarding CMEs with very high LASCO C3 speeds. 相似文献