首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16篇
  免费   1篇
航空   2篇
航天技术   10篇
航天   5篇
  2014年   2篇
  2009年   1篇
  2008年   1篇
  2005年   1篇
  2000年   2篇
  1993年   6篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
排序方式: 共有17条查询结果,搜索用时 15 毫秒
11.
The SIGMA telescope realizes images of the sky in the hard X-ray domain (40 keV–1.3 MeV) through a coded mask system. The extragalactic study was one of the main objectives and has brought new results in our knowledge of the Active Galactic Nuclei behavior at high energy.

In fact, the variability is the most important factor as all these objects have been showed to display strong evolution in intensity or/and spectral shape. Moreover, the discovery of a new hard X-ray source close to 3C273 and probably strongly absorbed below 40–50 keV could have many consequences in the extragalactic field.  相似文献   

12.
The main goals of the Chibis-M mission are the testing of a new micro-satellite technology, the study of new physical processes related to lightning activity and the verification of possible monitoring techniques of Space Weather phenomena. In frames of the Chibis-M mission an electromagnetic wave complex MWC is installed on board of the satellite composed of electromagnetic sensors and SAS3 measuring unit. The obtained data show that the scientific instrumentation operates properly and produces interesting information. Here we present the first results of the first year of operation of the MWC in the ELF–VLF bands in different operation modes. An important conclusion is that basing on the experience of the first year it is possible to realize an effective and reliable Space Weather monitoring system using micro-satellites and simultaneously operating ground support equipments.  相似文献   
13.
Semkin  N.D.  Novikov  L.S.  Voronov  K.E.  Bobin  D.G.  Pomelnikov  R.A.  Rotov  S.V. 《Space Debris》2000,2(4):273-293
The mathematical model of a space debris detector based on inflatable metal-dielectric-metal (MDM) film structure is presented. The efficiency of its implementation for detection of space debris particles at different altitudes is estimated, and the information obtained by the detector is investigated.  相似文献   
14.
The paper deals with the construction of physical/chemical life support systems of orbiting space station Mir and the Russian segment of the international space station (ISS). Based on experience gained in development and long-term operation of systems for water recovery and air revitalization balance and energy/mass characteristics of promising life support systems (LSS) are analyzed. Physical/chemical life support systems with regenerative systems updated as a result of the operation on the ISS may be used at an initial phase of manned interplanetary missions.  相似文献   
15.
为了降低发动机转子高速旋转产生的振动,提高发动机的使用寿命,设计了一种端部安装金属橡胶环的新型挤压油膜阻尼器,并在π油膜假设条件下,利用斯托克斯方程和雷诺方程,给出了新型金属橡胶挤压油膜阻尼器的流量表达式以及非线性油膜力的近似表达式。通过传统短挤压油膜阻尼器和新型金属橡胶挤压油膜阻尼器的流量特性和油膜力特性的对比分析,表明新型金属橡胶挤压油膜阻尼器具有更好的阻尼性能和良好的节流特性。并通过试验证明了新型金属橡胶挤压油膜阻尼器具有更好的阻尼减振效果。  相似文献   
16.
A method for determination of the vibrational distributions and populations of individual vibrational levels of vibrationally-nonequilibrated carbon dioxide in bend-stretch manifold and asymmetric stretching mode was developed and substantiated. The method is based on the measurements of integrated radiation intensity in the wide spectral intervals of the 15 μm CO2 band and total emissivities of its appropriate Q-branches. Computations of radiation intensities and emissivities in P and R-branches were performed by using vibrational-rotational band models and in Q-branches by the direct “line-by-line” integration.It was shown that vibrational temperature of CO2 asymmetric stretching mode may be determined from the measurements of integrated radiation intensity of the 15 μm band. The populations of individual levels of the bend-stretch manifold may be obtained from the measurements of total emissivities of some Q-branches of the 15 μm band.The procedure of the CO2 lower vibrational levels populations determination under the conditions typical of 18 μm and 9–11 μm CO2 laser cavities is described.  相似文献   
17.
Venera-Halley mission is to be launched to Venus in Dec. 1984. It will fly by Venus in June 1985. Separation of the cometary probe and Venera descend module will take place at that time. The gravitational swing-by at Venus will provide the encounter with the Halley comet in March 1986. The remote sensing of the inner coma (TV-imagery, spectrometry in the region from 1200 A to 12 μm, polarimetry) and of the nucleus, direct measurements of dust fluxes, dust composition, plasma and magnetic field are planned in the framework of multinational cooperation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号