排序方式: 共有102条查询结果,搜索用时 234 毫秒
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R. J. Macdowall M. D. Desch M. L. Kaiser R. G. Stone R. A. Hess A. Balogh S. J. Bame B. E. Goldstein 《Space Science Reviews》1995,72(1-2):125-128
A primary goal of the Ulysses mission is to study the 3-dimensional structures making up the interplanetary medium, and example of which is the high speed solar wind stream observedin situ by Ulysses beginning in July 1992. In order to study the longitudinal extent of this stream as a function of Ulysses' increasing heliographic latitude, a second point of reference is required to separate spatial and temporal variations. Such a reference point is provided at Jupiter by a class of Jovian radio bursts, whose occurrence rate varies in a predictable way with solar wind speed. Using thein situ and remote observations from Ulysses, the extent of the high speed stream at 5 AU is mapped and compared to the associated coronal hole boundary on the Sun. 相似文献
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Walls B. McClelland M. Persyn S. Werner D.-M. 《Aerospace and Electronic Systems Magazine, IEEE》2002,17(7):9-13
The advent of NASA-JPL's X2000 architecture has brought compactPCI (cPCI) to the forefront as the system bus of choice for space data processing. This paper presents a hybrid architecture allowing the inclusion of new, high performance cPCI modules with heritage VME-based modules. The hybrid system yields a cost-effective, performance optimized processing solution for space 相似文献
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Andreas Rittweger Werner Beuchel Martin G. Andersen Jochen Albus 《Acta Astronautica》2005,57(12):877-886
The dynamic qualification of the new cryogenic upper stage ESC-A of the ARIANE 5 is supported by several tests in order to verify the assumptions and the modeling approach made at the beginning of the development. The stage contains a large amount of equipment such as propellant lines, acceleration rockets, batteries, fluid control equipment etc. For the low frequency domain the verification of the equipment responses in the integrated state was done by a sine vibration test, excited to levels representing the predicted flight loads including a qualification factor. Acoustic tests with the upper stage were performed to verify the random vibration responses in the frequency range up to 2000 Hz. To verify the shock response level induced by stage separation (pyro-shock) a stage separation test was performed. The paper concentrates on the experience made with the modal identification and sine vibration test of the stage. For the sine vibration test an electro-dynamic multi-shaker table was used. It was able to produce the required input precisely up to as specified, not an easy task for a test set-up of 20 tons weight. The paper presents the approach of how the dynamic qualification was reached successfully and highlights the experience accomplished. 相似文献
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J. S. Kaastra A. M. Bykov S. Schindler J. A. M. Bleeker S. Borgani A. Diaferio K. Dolag F. Durret J. Nevalainen T. Ohashi F. B. S. Paerels V. Petrosian Y. Rephaeli P. Richter J. Schaye N. Werner 《Space Science Reviews》2008,134(1-4):1-6
We present the work of an international team at the International Space Science Institute (ISSI) in Bern that worked together
to review the current observational and theoretical status of the non-virialised X-ray emission components in clusters of
galaxies. The subject is important for the study of large-scale hierarchical structure formation and to shed light on the
“missing baryon” problem. The topics of the team work include thermal emission and absorption from the warm-hot intergalactic
medium, non-thermal X-ray emission in clusters of galaxies, physical processes and chemical enrichment of this medium and
clusters of galaxies, and the relationship between all these processes. One of the main goals of the team is to write and
discuss a series of review papers on this subject. These reviews are intended as introductory text and reference for scientists
wishing to work actively in this field. The team consists of sixteen experts in observations, theory and numerical simulations. 相似文献
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P. R. Gazis A. Balogh S. Dalla R. Decker B. Heber T. Horbury A. Kilchenmann J. Kota H. Kucharek H. Kunow D. Lario M. S. Potgieter J. D. Richardson P. Riley L. Rodriguez G. Siscoe R. von Steiger 《Space Science Reviews》2006,123(1-3):417-451
Interplanetary coronal mass ejections (ICMEs) propagate into the outer heliosphere, where they can have a significant effect on the structure, evolution, and morphology of the solar wind, particularly during times of high solar activity. They are known to play an important role in cosmic ray modulation and the acceleration of energetic particles. ICMEs are also believed to be associated with the large global transient events that swept through the heliosphere during the declining phases of solar cycles 21 and 22. But until recently, little was known about the actual behavior of ICMEs at large heliographic latitudes and large distances from the Sun. Over the past decade, the Ulysses spacecraft has provided in situ observations of ICMEs at moderate heliographic distances over a broad range of heliographic latitudes. More recently, observations of alpha particle enhancements, proton temperature depressions, and magnetic clouds at the Voyager and Pioneer spacecraft have begun to provide comparable information regarding the behavior of ICMEs at extremely large heliocentric distances. At the same time, advances in modeling have provided new insights into the dynamics and evolution of ICMEs and their effects on cosmic rays and energetic particles. 相似文献
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Hans J. Haubold Werner R. Balogh 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009,43(12):1854-1862
Since 1991 the United Nations Office for Outer Space Affairs has been conducting a series of workshops on basic space science under its United Nations Programme on Space Applications. Up to 2004 the workshops focussed on capacity building efforts in basic space science, in particular for the benefit of developing countries. From 2005 onwards the workshops and their related activities contributed to the celebration of the International Heliophysical Year 2007. Together these activities and workshops constitute the United Nations Basic Space Science Initiative of the United Nations Office for Outer Space Affairs. This paper reflects on the achievements and outcomes of the Initiative and informs about considerations for its future evolution. 相似文献
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