全文获取类型
收费全文 | 2668篇 |
免费 | 7篇 |
国内免费 | 13篇 |
专业分类
航空 | 1318篇 |
航天技术 | 1052篇 |
综合类 | 10篇 |
航天 | 308篇 |
出版年
2019年 | 18篇 |
2018年 | 24篇 |
2017年 | 18篇 |
2016年 | 18篇 |
2014年 | 48篇 |
2013年 | 58篇 |
2012年 | 51篇 |
2011年 | 82篇 |
2010年 | 60篇 |
2009年 | 104篇 |
2008年 | 158篇 |
2007年 | 63篇 |
2006年 | 66篇 |
2005年 | 69篇 |
2004年 | 79篇 |
2003年 | 80篇 |
2002年 | 51篇 |
2001年 | 75篇 |
2000年 | 49篇 |
1999年 | 63篇 |
1998年 | 80篇 |
1997年 | 49篇 |
1996年 | 61篇 |
1995年 | 78篇 |
1994年 | 76篇 |
1993年 | 49篇 |
1992年 | 61篇 |
1991年 | 31篇 |
1990年 | 30篇 |
1989年 | 70篇 |
1988年 | 26篇 |
1987年 | 28篇 |
1986年 | 30篇 |
1985年 | 120篇 |
1984年 | 68篇 |
1983年 | 57篇 |
1982年 | 58篇 |
1981年 | 103篇 |
1980年 | 34篇 |
1979年 | 26篇 |
1978年 | 24篇 |
1977年 | 28篇 |
1976年 | 18篇 |
1975年 | 31篇 |
1974年 | 19篇 |
1973年 | 25篇 |
1972年 | 20篇 |
1971年 | 16篇 |
1970年 | 24篇 |
1969年 | 26篇 |
排序方式: 共有2688条查询结果,搜索用时 0 毫秒
131.
卢兴猷 《南京航空航天大学学报(英文版)》1998,(1)
香港工商企业的质量管理大部分都采用西方的质量管理概念。每当范畴扩展到建立人的优质思想和意识时,便遇到不少困难,基于上述问题,作者进行了一系列的研究,希望了解‘文化’与‘优质管理’之间的关系,并将中国的优良文化传统应用于现代质量管理之中。研究结果显示,‘管理哲学’是重要的一环,而我国的哲学极为丰富,作者借此文章,希望引起更多中国人在这方面的兴趣,从而进行更深入地研究和推广。 相似文献
132.
133.
K. Yoshimura K. Abe H. Fuke S. Haino T. Hams M. Hasegawa A. Horikoshi K.C. Kim T. Kumazawa A. Kusumoto M.-H. Lee Y. Makida S. Matsuda Y. Matsukawa J.W. Mitchell A.A. Moiseev J. Nishimura M. Nozaki R. Orito J.F. Ormes K. Sakai M. Sasaki E.S. Seo Y. Shikaze R. Shinoda R.E. Streitmatter J. Suzuki K. Takeuchi N. Thakur K. Tanaka T. Yamagami A. Yamamoto T. Yoshida 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
134.
L. M. Bartolone K. Carney S. B. Cohen J. Erickson J. Gutbezahl P. H. Knappenberger Jr. D. J. McComas 《Space Science Reviews》2009,146(1-4):353-369
The IBEX mission includes a comprehensive Education and Public Outreach (E/PO) program that develops programs and products in exciting themes from astronomy and space physics. With the active involvement of the Principal Investigator and several science team partners, it is overseen and implemented by the Adler Planetarium & Astronomy Museum. The program includes an internationally distributed planetarium show with accompanying informal education materials that are also accessible to individuals with special needs; a national Space Science Core Curriculum for grades 6–8 in collaboration with other NASA missions; a professional development program for teachers; and workshops that engage Hispanic and Native American students. Materials are made available for download or for order via the IBEX website: http://www.ibex.swri.edu/. Our program is developed, implemented and monitored for effectiveness by organizations with proven capabilities and experience in their respective areas of E/PO. This paper describes these program elements in detail and includes the rationale and design process for this E/PO program. 相似文献
135.
136.
Multiposition alignment of strapdown inertial navigation system 总被引:3,自引:0,他引:3
Lee J.G. Park C.G. Park H.W. 《IEEE transactions on aerospace and electronic systems》1993,29(4):1323-1328
The authors demonstrate that the stationary alignment of strapdown inertial navigation system (SDINS) can be improved by employing the multiposition/technique. Using an observability analysis, it is shown that an optimal two-position alignment not only satisfies complete observability conditions but also minimizes alignment errors. This is done by analytic rank testing of the stripped observability matrix and numerical calculation of the error covariance. It is also shown that an optimal three-position alignment accelerates the convergence of the alignment error compared with two-position alignment 相似文献
137.
R. Srama T. J. Ahrens N. Altobelli S. Auer J. G. Bradley M. Burton V. V. Dikarev T. Economou H. Fechtig M. Görlich M. Grande A. Graps E. Grün O. Havnes S. Helfert M. Horanyi E. Igenbergs E. K. Jessberger T. V. Johnson S. Kempf A. V. Krivov H. Krüger A. Mocker-Ahlreep G. Moragas-Klostermeyer P. Lamy M. Landgraf D. Linkert G. Linkert F. Lura J. A. M. McDonnell D. Möhlmann G. E. Morfill M. Müller M. Roy G. Schäfer G. Schlotzhauer G. H. Schwehm F. Spahn M. Stübig J. Svestka V. Tschernjawski A. J. Tuzzolino R. Wäsch H. A. Zook 《Space Science Reviews》2004,114(1-4):465-518
The Cassini-Huygens Cosmic Dust Analyzer (CDA) is intended to provide direct observations of dust grains with masses between 10−19 and 10−9 kg in interplanetary space and in the jovian and saturnian systems, to investigate their physical, chemical and dynamical properties as functions of the distances to the Sun, to Jupiter and to Saturn and its satellites and rings, to study their interaction with the saturnian rings, satellites and magnetosphere. Chemical composition of interplanetary meteoroids will be compared with asteroidal and cometary dust, as well as with Saturn dust, ejecta from rings and satellites. Ring and satellites phenomena which might be effects of meteoroid impacts will be compared with the interplanetary dust environment. Electrical charges of particulate matter in the magnetosphere and its consequences will be studied, e.g. the effects of the ambient plasma and the magnetic field on the trajectories of dust particles as well as fragmentation of particles due to electrostatic disruption.The investigation will be performed with an instrument that measures the mass, composition, electric charge, speed, and flight direction of individual dust particles. It is a highly reliable and versatile instrument with a mass sensitivity 106 times higher than that of the Pioneer 10 and 11 dust detectors which measured dust in the saturnian system. The Cosmic Dust Analyzer has significant inheritance from former space instrumentation developed for the VEGA, Giotto, Galileo, and Ulysses missions. It will reliably measure impacts from as low as 1 impact per month up to 104 impacts per second. The instrument weighs 17 kg and consumes 12 W, the integrated time-of-flight mass spectrometer has a mass resolution of up to 50. The nominal data transmission rate is 524 bits/s and varies between 50 and 4192 bps.This revised version was published online in July 2005 with a corrected cover date. 相似文献
138.
J. B. Blake B. H. Mauk D. N. Baker P. Carranza J. H. Clemmons J. Craft W. R. Crain A. Crew Y. Dotan J. F. Fennell R. H. Friedel L. M. Friesen F. Fuentes R. Galvan C. Ibscher A. Jaynes N. Katz M. Lalic A. Y. Lin D. M. Mabry T. Nguyen C. Pancratz M. Redding G. D. Reeves S. Smith H. E. Spence J. Westlake 《Space Science Reviews》2016,199(1-4):309-329
139.
R. Schmidt H. Arends W. Riedler K. Torkar F. Rüdenauer M. Fehringer B. Maehlum B. Narheim 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(12):61-64
Future space missions aiming at the accurate measurement of cold plasmas and DC to very low frequency electric fields will require that the potential of their conductive surfaces be actively controlled to be near the ambient plasma potential. In the near-Earth space these spacecraft are usually solar-cell powered; consequently, parts of their surface are most of the time exposed to solar photons. Outside the plasmasphere, a positive surface potential due the dominance of surface-emitted photoelectrons over ambient plasma electrons is to be expected. Photo- and ambient electrons largely determine the potential and positive values between a few Volts up to 100 V have been observed. Active ion emission is the obvious solution of this problem. A liquid metal ion emitter and a saddle field ion emitter are nearing the stage of flight unit fabrication. We will attempt to clamp the spacecraft potential to values close to the plasma potential. We present first results from vacuum chamber tests and describe the emission behaviour and characteristics of emitters producing, respectively, In+ and N2+ beams with an energy of ≥ 5 keV. 相似文献
140.
Y. Wu D.Y. Yang P.F. Tu Y.Z. Tian Y.H. Guo X.M. Wang X.B. Li 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
The dried, fleshy stems of Cistanche deserticola (Orobanchaceae) are popular tonics in Traditional Chinese Medicine (TCM) to treat the inability of kidney in expelling extra fluid in the body, causing fluid retention, and reform reproductive system. However, the wild plants of C. deserticola have become endangered due to habitat downsizing and over-harvesting for its medicinal usages. The present research was carried out for the following purposes: (1) promoting the space-breeding research; (2) providing molecular evidence for agricultural selective breeding; and (3) protecting this endangered herbal medicine and conserving its genetic resources. 相似文献