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231.
D W Sammons U Zimmermann N R Klinman P Gessner R C Humphreys S P Emmons G A Neil 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(1):363-372
The influence of microgravity on lymphocyte activation is central to the understanding of immunological function in space. Moreover, the adaptation of groundbased technologies to microgravity conditions presents opportunities for biotechnological applications including high efficiency production of antibody forming hybridomas. Because the emerging technology of microgravity hybridoma generation is dependent upon activation and cultivation of B lymphocytes during flight, we have adapted mitogen-driven B lymphocyte stimulation and culture that allows for the in vitro generation of large numbers of antibody forming cells suitable for cell fusion over a period of 1-2 weeks. We believe that this activation and cultivation system can be flown on near-term space flights to test fundamental hypotheses about mammalian cell activation, cell fusion, metabolism, secretion, growth, and bio-separation. 相似文献
232.
U. Schmidt A. Khedim D. Knapska G. Kulessa F.J. Johnen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(4):131-134
A newly developed balloon-borne cryogenic sampler has been used to collect large air samples in the midlatitude stratosphere (44° N). The samples were analysed for their content of several longlived trace gases. The vertical profiles of N2O, CH4, and CF2Cl2 derived from two balloon flights in winter 1982 and, as part of the MAP Globus Project, in fall 1983 indicate variations that are caused by large scale dynamic processes. Significant features of the profiles are discussed and compared with averaged profiles that were derived from a series of balloon sampling flights performed previously over the same location during the summer season. The temporal variation of the individual profiles is more detailed than predicted by model calculations. 相似文献
233.
234.
U. Huth 《Acta Astronautica》1981,8(1):79-85
This paper reviews shortly the results obtained by a preliminary call for experiment proposals for future Spacelab flights issued by the European Space Agency in April 1978. The results of this call indicate clearly the trend towards experiments performing studies on the state and the evolution of fluid media. The instrumentation used are mainly multipurpose instruments (furnaces, process chambers) already under development for the first Spacelab flight and new equipment currently under study. 相似文献
235.
Private and commercial activity in outer space still poses challenges to space law and policy. Within ‘Project 2001’—a legal research project by the University of Cologne's Institute of Air and Space Law and the German Aerospace Center (DLR)—six international expert working groups examined international and national laws, in order to identify gaps and, where necessary, propose improvements to the present legal framework for private space activities. The results were presented and discussed at an international colloquium in May 2001 in Cologne, Germany, where final conclusions have been drawn. This report presents a summary of the project's work and main conclusions, which are documented in full in a comprehensive book to be published in May 2002. 相似文献
236.
Griessmeier JM Stadelmann A Motschmann U Belisheva NK Lammer H Biernat HK 《Astrobiology》2005,5(5):587-603
Because of their different origins, cosmic rays can be subdivided into galactic cosmic rays and solar/stellar cosmic rays. The flux of cosmic rays to planetary surfaces is mainly determined by two planetary parameters: the atmospheric density and the strength of the internal magnetic moment. If a planet exhibits an extended magnetosphere, its surface will be protected from high-energy cosmic ray particles. We show that close-in extrasolar planets in the habitable zone of M stars are synchronously rotating with their host star because of the tidal interaction. For gravitationally locked planets the rotation period is equal to the orbital period, which is much longer than the rotation period expected for planets not subject to tidal locking. This results in a relatively small magnetic moment. We found that an Earth-like extrasolar planet, tidally locked in an orbit of 0.2 AU around an M star of 0.5 solar masses, has a rotation rate of 2% of that of the Earth. This results in a magnetic moment of less than 15% of the Earth's current magnetic moment. Therefore, close-in extrasolar planets seem not to be protected by extended Earth-like magnetospheres, and cosmic rays can reach almost the whole surface area of the upper atmosphere. Primary cosmic ray particles that interact with the atmosphere generate secondary energetic particles, a so-called cosmic ray shower. Some of the secondary particles can reach the surface of terrestrial planets when the surface pressure of the atmosphere is on the order of 1 bar or less. We propose that, depending on atmospheric pressure, biological systems on the surface of Earth-like extrasolar planets at close-in orbital distances can be strongly influenced by secondary cosmic rays. 相似文献
237.
Manned spaceflight has been an important element of the German space program over the last decades. This is demonstrated by the nationally managed space missions Spacelab D-l (1985), D-2 (1993), and MIR '92 as well as by the participation in the 1st Spacelab mission FSLP (1983), the NASA missions IML-1 (1992) and IML-2 (1994), as well as in the ESA missions EUROMIR '94 and '95. On February 12th, this year, the German cosmonaut Reinhold Ewald was launched together with his Russian colleagues Wasilij Zibliew and Alexander Lasudkin onboard of a Soyuz spacecraft for another stay of a German cosmonaut onboard of the Russian Space Station MIR. This mission--the so-called German/Russian MIR '97--was, of course, another cornerstone with regard to the cooperation between Russian and German space organizations. The cooperation in the area of manned missions began 1978 with the flight of the German cosmonaut Sigmund Jahn onboard of Salyut 6, at that time a cooperation between the Soviet Union and the German Democratic Republic in the frame of the Interkosmos Program. In March 1992, it was followed by the flight of Klaus Dietrich Flade with his stay onboard of MIR. After two further successful ESA missions, EUROMIR '94 and '95 with the two German cosmonauts Ulf Merbold and Thomas Reiter and with a marked contribution of German scientists, the decision was taken to perform another German/Russian MIR mission, the so-called MIR '97. In Germany, MIR'97 was managed and performed in a joint effort between several partners. DARA, the German Space Agency, was responsible for the overall program and project management, while DLR, the German Aerospace Research Establishment, was responsible for the cosmonaut training, for medical operations, for the mission control at GSOC in Oberpfaffenhofen as well as for user support. 相似文献
238.
Radiation biology in space: a critical review. 总被引:12,自引:0,他引:12
U Hagen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1989,9(10):3-8
A short summary of the results of radiobiological studies in space or on respective particles on ground will be given. Among the various types of radiation in space, the effect of heavy ions with high energy (HZE-particles) are most essential. Thus, radiobiology in space concerns mostly to the effect of these particles, in cells and in whole organism. Cell death, mutation and malignant transformation are the relevant endpoints, with can be studied on ground with heavy ions of different energy with suitable accelerators or in space, especially by the BIOSTACK concept. In space, however, the effect of microgravity has to be considered as well and there are hints, that under weightlessness the biological effect of radiation may be enhanced. There are still open questions to be answered concerning radioprotection of man in space. Further experiments are necessary. 相似文献
239.
在并行工程的实施过程中,上下游阶段交叠形式的不合理安排将会给产品的开发带来不可预见的风险。如何决定各并行阶段的启动时间一直是困扰实施并行工程企业的问题。对于这方面的研究工作目前大多只限于概念模型分析的层面,而没有具体的数学模型。中应用Shannon信息熵量化了上下游阶段的交互信息和系统的有序度,建立了基于多层次模糊综合评判和BP神经网络的动态模型来实时确定下游阶段的启动时间。最后给出了基于PDM的实施框架和该模型的应用实例。 相似文献
240.
A. Balogh V. Bothmer N.U. Crooker R.J. Forsyth G. Gloeckler A. Hewish M. Hilchenbach R. Kallenbach B. Klecker J.A. Linker E. Lucek G. Mann E. Marsch A. Posner I.G. Richardson J.M. Schmidt M. Scholer Y.-M. Wang R.F. Wimmer-Schweingruber M.R. Aellig P. Bochsler S. Hefti Z. Mikić 《Space Science Reviews》1999,89(1-2):141-178
Corotating Interaction Regions (CIRs) form as a consequence of the compression of the solar wind at the interface between
fast speed streams and slow streams. Dynamic interaction of solar wind streams is a general feature of the heliospheric medium;
when the sources of the solar wind streams are relatively stable, the interaction regions form a pattern which corotates with
the Sun. The regions of origin of the high speed solar wind streams have been clearly identified as the coronal holes with
their open magnetic field structures. The origin of the slow speed solar wind is less clear; slow streams may well originate
from a range of coronal configurations adjacent to, or above magnetically closed structures. This article addresses the coronal
origin of the stable pattern of solar wind streams which leads to the formation of CIRs. In particular, coronal models based
on photospheric measurements are reviewed; we also examine the observations of kinematic and compositional solar wind features
at 1 AU, their appearance in the stream interfaces (SIs) of CIRs, and their relationship to the structure of the solar surface
and the inner corona; finally we summarise the Helios observations in the inner heliosphere of CIRs and their precursors to
give a link between the optical observations on their solar origin and the in-situ plasma observations at 1 AU after their
formation. The most important question that remains to be answered concerning the solar origin of CIRs is related to the origin
and morphology of the slow solar wind.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献