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   35篇
  免费   0篇
航空   6篇
航天技术   24篇
综合类   1篇
航天   4篇
  2021年   1篇
  2014年   2篇
  2013年   2篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2009年   1篇
  2008年   11篇
  2004年   4篇
  2003年   3篇
  1992年   1篇
  1987年   1篇
  1985年   1篇
  1981年   1篇
  1979年   1篇
排序方式: 共有35条查询结果,搜索用时 0 毫秒
31.
The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) was flown from Lynn Lake, Manitoba, Canada in August, 2000, during the maximum solar modulation period, with an average residual atmospheric overburden of 4.3 g/cm2. Precise spectral measurements of cosmic ray hydrogen isotopes from 0.178 GeV/n to 1.334 GeV/n were made during the 28.7 h of flight. This paper presents the measured energy spectra and their ratio, 2H/1H. The results are also compared with previous measurements and theoretical predictions.  相似文献   
32.
Continuous path control of space manipulators mounted on OMV   总被引:5,自引:0,他引:5  
Theoretical analysis on the formulation of kinematics for the manipulator mounted on a satellite is presented. Firstly, to solve the inverse kinematics, the authors define a new generalized Jacobian matrix, and utilizing this generalized matrix, the problem can be treated analytically. Secondly, the authors verify the method proposed here in the simulation study. Thirdly, they also discuss on the several points which are indispensable for further investigations.  相似文献   
33.
Tardigrades are tiny (less than 1?mm in length) invertebrate animals that have the potential to survive travel to other planets because of their tolerance to extreme environmental conditions by means of a dry ametabolic state called anhydrobiosis. While the tolerance of adult tardigrades to extreme environments has been reported, there are few reports on the tolerance of their eggs. We examined the ability of hydrated and anhydrobiotic eggs of the tardigrade Ramazzottius varieornatus to hatch after exposure to ionizing irradiation (helium ions), extremely low and high temperatures, and high vacuum. We previously reported that there was a similar pattern of tolerance against ionizing radiation between hydrated and anhydrobiotic adults. In contrast, anhydrobiotic eggs (50% lethal dose; 1690 Gy) were substantially more radioresistant than hydrated ones (50% lethal dose; 509 Gy). Anhydrobiotic eggs also have a broader temperature resistance compared with hydrated ones. Over 70% of the anhydrobiotic eggs treated at either -196°C or +50°C hatched successfully, but all the hydrated eggs failed to hatch. After exposure to high-vacuum conditions (5.3×10(-4) Pa to 6.2×10(-5) Pa), the hatchability of the anhydrobiotic eggs was comparable to that of untreated control eggs.  相似文献   
34.
We study time evolution of an energy spectrum of a proton flux in the range of 47 – 4750 keV for the energeticparticle event occurred on 255 DOY in 1999, which we consider as one of typical diffusive acceleration events associated with interplanetary shocks and irrespective of large X-ray solar flares. Fast enhancement during evolution is found in the range of less than about 0.5 MeV. Our previous numerical simulations using Stochastic Differential Equation method could not show this behavior, although we obtained results showing a power law energy spectrum, which suggesting that energetic particles are accelerated diffusively by shock waves, the first-order Fermi acceleration. We consider that less than 0.5 MeV protons need to exist to explain behavior of the observational energy spectrum and perform numerical simulations in order to investigate proper injection models for this event.  相似文献   
35.
The General Anti-Particle Spectrometer (GAPS) project is being carried out to search for primary cosmic-ray antiparticles especially for antideuterons produced by cold dark matter. GAPS plans to realize the science observation by Antarctic long duration balloon flights in the late 2010s. In preparation for the Antarctic science flights, an engineering balloon flight using a prototype of the GAPS instrument, “pGAPS”, was successfully carried out in June 2012 in Japan to verify the basic performance of each GAPS subsystem. The outline of the pGAPS flight campaign is briefly reported.  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