全文获取类型
收费全文 | 978篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
航空 | 365篇 |
航天技术 | 369篇 |
综合类 | 2篇 |
航天 | 245篇 |
出版年
2022年 | 5篇 |
2021年 | 22篇 |
2019年 | 9篇 |
2018年 | 30篇 |
2017年 | 25篇 |
2016年 | 14篇 |
2015年 | 8篇 |
2014年 | 35篇 |
2013年 | 47篇 |
2012年 | 41篇 |
2011年 | 42篇 |
2010年 | 34篇 |
2009年 | 60篇 |
2008年 | 73篇 |
2007年 | 22篇 |
2006年 | 21篇 |
2005年 | 31篇 |
2004年 | 22篇 |
2003年 | 28篇 |
2002年 | 20篇 |
2001年 | 36篇 |
2000年 | 21篇 |
1999年 | 12篇 |
1998年 | 27篇 |
1997年 | 11篇 |
1996年 | 22篇 |
1995年 | 18篇 |
1994年 | 26篇 |
1993年 | 11篇 |
1992年 | 16篇 |
1991年 | 4篇 |
1989年 | 14篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 3篇 |
1985年 | 26篇 |
1984年 | 18篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 16篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1972年 | 8篇 |
1968年 | 6篇 |
1967年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有981条查询结果,搜索用时 31 毫秒
811.
H. E. Spence A. W. Case M. J. Golightly T. Heine B. A. Larsen J. B. Blake P. Caranza W. R. Crain J. George M. Lalic A. Lin M. D. Looper J. E. Mazur D. Salvaggio J. C. Kasper T. J. Stubbs M. Doucette P. Ford R. Foster R. Goeke D. Gordon B. Klatt J. O’Connor M. Smith T. Onsager C. Zeitlin L. W. Townsend Y. Charara 《Space Science Reviews》2010,150(1-4):243-284
812.
O. S. Ougolnikov 《Cosmic Research》2002,40(1):62-67
A technique for the determination of cosmic gamma-ray burst coordinates by measuring the time lag between gamma-ray burst signals on different spacecraft in the near-Sun orbits is developed. On the basis of the well-known relativistic time transformation between barycentric, geocentric, and instrumental coordinate frames of reference, the time corrections for specific spacecraft systems are calculated. Among various relativistic corrections, those are determined that are significant for the method in question. 相似文献
813.
G. N. Zastenker Yu. N. Agafonov N. A. Eismont A. V. Prudkoglyad V. V. Khrapchenkov L. G. Gevorkov S. A. Burguchev A. V. Kochetkov E. Salerno F. Buehler P. Bochsler J. Fisher M. Bassi G. Busemann O. Eugster 《Cosmic Research》2002,40(4):347-357
One of the important astrophysical problems is the determination of the abundance of helium isotopes 3He and 4He in different regions of the Universe, because this abundance can reflect its history by pointing to the intensity of various possible processes of the creation and decay of light elements. This paper describes the method and results of the determination (for the first time performed by a direct method) of the helium isotopic abundance in the local interstellar medium surrounding the Solar system. The experiment was carried out on the manned Mir space station by long-term space exposure of samples of metal foil with their subsequent recovery to the Earth and detailed laboratory mass-spectrometric analysis. As a result, we succeeded in obtaining an estimation of the 4He concentration (about 7.5 × 10–3 cm–3) and the isotopic ratio 3He/4He (about1.7 × 10–4) for the local interstellar medium. 相似文献
814.
The first results of multiwave measurements of twilight background and the all-sky camera with a color (RGB) CCD matrix conducted in the spring and summer of 2016 in Central Russia (55.2° N, 37.5° E) have been discussed. The observations reveal the effect of aerosol scattering at heights of up to 35 km, which is substantially enhanced in the long-wave part of the spectrum (R band with an effective wavelength of 624 nm). An analysis of the behavior of the sky color during light period of twilight with allowance for the absorption by ozone in the Chappuis bands make it possible to restore the angular dependences of the intensity of the aerosol scattering of the light. This is used to determine the parameters of the lognormal distribution of aerosol particles over their sizes with a mean radius of 0.08 μm and a width of 1.5–1.6 for the stratospheric height interval. 相似文献
815.
到目前为止,基于发光二极管(Light Emitting Diodes-based,LED)的照明器被广泛用于除自然光之外的温室植物照明,以及没有自然光的植物工厂.优化人工光照参数,如日光照积分和不同光谱成分的比值,可以显著降低生物生命支持系统(Biological Life Support Systems,BLSS)... 相似文献
816.
This paper gives a brief outline of the progression from the first substorm model developed in Ref.[4] and[8] based on Kennel's ideas[3], to the present views about the mechanism by which solar wind kinetic energy is converted to electromagnetic energy at the Bow Shock and by which this energy is transferred to the magnetosphere in the form of current; about the transformation of the energy of this current to gas kinetic energy of convecting plasma tubes, and, finally, the back transformation of gas kinetic energy to electromagnetic energy in secondary magnetospheric MHD generators. The questions of the formation of the magnetospheric convection system, the nature of substorm break-up, and of the matching of currents in the magnetosphere-ionosphere system are discussed. 相似文献
817.
A I Grigoriev L B Buravkova V A Loginov O L Vinogradova 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1997,20(7):1397-1399
The problems and approaches to organisation of the education process in the field of aerospace and environmental medicine for medical students are discussed. Original education developed on the basis of Russian experience in space biology and physiology, environmental medicine, aerospace medicine and medical support during spaceflight. The main goals of these programs are to acquaint students with: interaction of living organisms with natural and artificial surroundings, including space flight conditions; the physiological reactions on extreme environmental factors; basic mechanisms of human adaptation to space flight and particularly to microgravity; the current research in space medicine and new telecommunication technologies. All programs are formed in accordance with contemporary progress in life sciences and revealed a result of the interdisciplinary approach to education process. 相似文献
818.
A. Dmitriev S. Kuznetsov P. Shavrin V. Lyagushin O. Nechaev M. Panasyuk E. Tolstaya M. Nikiforova 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1998,21(12):1797-1800
A set of instruments for measuring energetic particle fluxes, containing two neutron detectors under different plexiglas shielding thicknesses, a scintillation detector, measuring energy release >0. I MeV and 0.5 MeV and a Geiger counter were launched onboard OS ‘MIR’. The latitude dependencies of the cosmic ray measurements were obtained and studied. The distributions of primary particle fluxes (protons and electrons) as well as secondary particle fluxes (bremsstrahlung gamma-rays and neutrons) produced in interactions of radiation belt particles with the station materials were obtained. The electron belt, generated during the storm of March 24 1991, is studied. 相似文献
819.
J. Kleczek H. Nussbaumer K. A. van der Hucht J. P. de Greve G. Ooms R. J. Rutten H. van der Laan F. W. Jäger G. C. M. Reijnen w. Bijleveld J. Kistemaker C. de Jager E. R. Mustel Y. Ne'eman E. R. Priest H. Stiller W. Seifert O. Namba M. Kuperus Roel Hoekstra F. L. H. M. Stumpers S. Frank J. T. F. Zimmerman C. de Loore R. Gendrin J. Schrijver P. S. Mulder K. A. Pounds R. S. Young L. Houziaux O. Engvold B. J. Bok W. de Graaff 《Space Science Reviews》1983,36(4):415-432
820.
O. Ooms Hans Van Der Woerd Henny J. G. L. M. Lamers Josip Kleczek J. Kovalevsky R. Gathier T. Jarzebowski J. P. Swings K. A. van der Hucht O. Namba R. Mewe D. Lynden-Bell Jan Kuijpers M. van der Klis D. de Hoop H. Wittenberg W. Iwanowska P. S. Thé J. Schrijver S. R. Pottasch 《Space Science Reviews》1984,38(3-4):385-387