全文获取类型
收费全文 | 76篇 |
免费 | 0篇 |
专业分类
航空 | 17篇 |
航天技术 | 13篇 |
航天 | 46篇 |
出版年
2018年 | 1篇 |
2017年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1985年 | 4篇 |
1982年 | 1篇 |
1967年 | 3篇 |
1966年 | 1篇 |
排序方式: 共有76条查询结果,搜索用时 15 毫秒
11.
R. Harris 《Space Policy》1999,15(4):233-235
The second workshop of the EOPOLE project was held in Cosenza, Italy, 10–12 May 1999, organised by Microwave Consultant Engineering (MiCE). Its purpose was to address the user issues related to Earth observation data policy. This report presents the main conclusions of the workshop. The different approaches among lead departments within national governments emerged as one of the main areas of which users in Europe need to be aware. 相似文献
12.
13.
Jaekl P Zikovitz DC Jenkin MR Jenkin HL Zacher JE Harris LR 《Acta Astronautica》2005,56(9-12):1033-1040
We measured the amount of visual movement judged consistent with translational head movement under normal and microgravity conditions. Subjects wore a virtual reality helmet in which the ratio of the movement of the world to the movement of the head (visual gain) was variable. Using the method of adjustment under normal gravity 10 subjects adjusted the visual gain until the visual world appeared stable during head movements that were either parallel or orthogonal to gravity. Using the method of constant stimuli under normal gravity, seven subjects moved their heads and judged whether the virtual world appeared to move “with” or “against” their movement for several visual gains. One subject repeated the constant stimuli judgements in microgravity during parabolic flight. The accuracy of judgements appeared unaffected by the direction or absence of gravity. Only the variability appeared affected by the absence of gravity. These results are discussed in relation to discomfort during head movements in microgravity. 相似文献
14.
Harris PR 《Space Policy》1989,5(2):147-154
Space exploration is now moving beyond the stage when technical development dominated research. As thinking shifts towards the problems of long-term colonization of the Solar System, the biological and behavioural sciences must make major contributions. This article outlines some of the issues which must be addressed, such as group behaviour and dynamics in space flight, the environment created at space stations and other outposts, recruitment and training of suitable spacefarers, and the planning and governing of space settlements. Ten dimensions of the human aspect of space habitation are described and an indication given of how they may form the basis for a new taxonomy of space planning, operations and management. 相似文献
15.
China's advances in space include plans for a state-of-the-art space theme park, based on a new launch center, which promises to show up the outdated and ‘user unfriendly’ public visitor centers at most US space sites. Yet providing better public outreach in the form of theme parks would both inspire large numbers of the general population and provide a useful source of revenue. NASA should show more imagination in the exhibits and facilities it present to the public; it could use various science museums and Hollywood as models. 相似文献
16.
17.
Harris PR 《Acta Astronautica》1995,36(7):399-408
The Space Age is causing new applications to the concept of culture, a human coping tool. The exploration and exploitation of outer space resources are altering human culture both on Earth and in orbit. For the first time in history, our species need not merely react and adapt to environment, but plan for a space culture appropriate for extraterrestrial migration. The impact of culture can be analyzed in terms of how space developments alter human perceptions and behavior on this planet; the emergence of a new culture to suit the orbital environment; the organizations that build spacecraft and deploy people aloft; and the technological systems created for spacefaring. This article presents a paradigm for analyzing some of the non-technical human factors involved in space undertakings. It also offers a method for classifying a culture according to ten categories which may be applied both to a macroculture, such as a lunar base; or a microculture, such as a space agency or crew. Human enterprise in space is viewed as both altering the species, and providing a challenge for expanded behavioral and biological scientific research on living and working in space. 相似文献
18.
Pricing policy for Earth observation data continues to be a problem for both supplier organizations and user organizations: there are incompatible or conflicting pricing policies used by different organizations in the Earth observation sector. This paper analyses the issues in Earth observation data pricing in two ways. First, it analyses the policy foundations which underlie Earth observation data pricing, such as return on investment, the basis of pricing policy and access conditions. Second, it presents five policy options for the pricing of Earth observation data, namely free data, marginal cost price, market driven price, two tier pricing and rebalancing of government funding. The paper concludes with an analysis of the forces acting on Earth observation data pricing policy. 相似文献
19.
H.G. Mayr I. Harris R.E. Hartle K.H. Schatten H.A. Taylor K.L. Chan D.R. Stevens-Rayburn 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(9):63-68
Superrotation on Venus is discussed in the context of comparative planetary atmospheres. In our planetary system, the rigid shell component (global average) of superrotation is ubiquitous (Jupiter, Saturn, Earth, Venus, Mars, Titan). The largest equatorial values of the component are between 25 and 150 m/sec. We present a simplified, heuristic analysis, utilizing mixing length theory to describe the small scale non-linear advections of energy and angular momentum, thereby providing a closure of the dynamic system. This leads to the conjecture that the zonal velocity may be crudely estimated by , approximating the observed planetary trends; with c the speed of sound, the parameter a being 1 or 2 for geostrophic or cyclostrophic conditions respectively, Pα an effective Prandtl number which becomes less than one when radiative cooling is important, So the average stability, Γ the adiabatic lapse rate and γ the ratio of specific heats. 相似文献
20.
STADAR is a Servo Tester with Automatic Data Acquisition and Reduction developed for the Apollo program. This paper describes the operational capability of STADAR and discusses certain aspects of the design. STADAR evaluates system performance by supplying an input stimuli and two data acquisition and analysis channels. Stimuli (0.02-30 c/s 0-10 V peak) are automatically programmed to a frequency accuracy of ±0.01 percent and an amplitude accuracy of ± 0.1 percent. Data acquisition accuracy is 0.1 percent or 50 microvolts. System design utilizes programmable data filters to improve system S/N ratio. Active filter mechanization methods and results are presented as well as techniques for instantaneous precise generation of stimuli which are automatically programmed. 相似文献