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931.
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933.
G. Facskó J.G. Trotignon I. Dandouras E.A. Lucek P.W. Daly 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
Hot flow anomalies (HFAs) were first discovered in the early 1980s at the bow shock of the Earth. In the 1990s these features were studied, observed and simulated very intensively and many new missions (Cluster, THEMIS, Cassini and Venus Express) focused the attention to this phenomenon again. Many basic features and the HFA formation mechanism were clarified observationally and using hybrid simulation techniques. We described previous observational, theoretical and simulation results in the research field of HFAs. We introduced HFA observations performed at the Earth, Mars, Venus and Saturn in this paper. We share different observation results of space mission to give an overview to the reader. 相似文献
934.
在简述火星与地球大气飞行环境差异的基础上,分析研究了火星飞机主要布局特征和动力推进问题;阐述了国外开展火星飞机研究发展的地面模拟设备--火星风洞的情况,意在跟踪国外新技术走向,为国内航空航天未来发展提供参考. 相似文献
935.
M.S. Potgieter 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(2):245-258
Voyager 1 crossed the solar wind termination shock on December 16, 2004 at a distance of 94 AU from the Sun, to become the first spacecraft to explore the termination shock region and to enter the heliosheath, the final heliospheric frontier. By the end of 2006, Voyager 1 will be at ∼101 AU, with Voyager 2 at ∼81 AU and still approaching the termination shock. Both spacecraft have been observing the modulation of galactic and anomalous cosmic rays since their launch in 1977. The recent observations close to or inside the heliosheath have provided several interesting ‘surprises’ with subsequent theoretical and modeling challenges. Examples are: what does the modulation of galactic cosmic rays amount to in this region?; how do the anomalous cosmic rays get accelerated and modulated?; why are there ‘breaks’ in the power-law slopes of the spectra of accelerated particles? Several numerical models have been applied to most of these topics over the years and comprehensive global predictions have been made the past decade, thought to be based on reasonable assumptions about the termination shock and the heliosheath. Examples of these predictions and assumptions are concisely discussed within the context of the main observed features of cosmic rays in the vicinity of the termination shock, ending with a discussion of some of the issues and challenges to cosmic ray modeling in particular. 相似文献
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937.
Larmor size transient structures with density depletions as large as 99% of ambient solar wind density levels occur commonly upstream of Earth's collisionless bow shock. These "density holes" have a me... 相似文献
938.
滚转通道是飞行器控制的重要通道,且在试验中滚转单元受天平其它元干扰较大。为了准确测量滚转力矩,特别开发了带五分量抑制机构的高精度滚转测量技术。该技术设计原理是通过带机械深沟球轴承的抑制机构对除滚转力矩外的五个分量进行抑制。该技术一方面具有较高的滚转力矩测量灵敏度,另一方面能够有效抑制除滚转力矩外的其它五个分量,从而得到准确滚转力矩信号。 相似文献
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940.
D. Mori A.V. Koustov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
In this study SuperDARN Cross Polar Cap Potentials (CPCPs), collected over the year 2000, are investigated with a goal to statistically assess its relationship with various parameters of the solar wind and Interplanetary Magnetic Field (IMF). We show that SuperDARN CPCPs tend to cluster around discrete values, prescribed by the statistical model, unless the amount of points on each convection map is above ∼300. By selecting CPCP data obtained with radar coverage of >300 points, we investigate the CPCP relationship with IMF Bz and By, IMF clock angle, solar wind speed and dynamic pressure, Alfven velocity, Alfven–Mach number, and interplanetary electric field. Some reported tendencies, such as dependence upon IMF Bz, were found to be consistent with measurements by other instruments. We demonstrate that SuperDARN CPCPs show consistency with several theories/empirical models (predicting the CPCP) in terms of a linear trend but, on average, the slopes of the dependencies are at least two times smaller. We also determine the coupling function, out of those published in literature, best correlating with SuperDARN CPCPs. 相似文献