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291.
S. Seetha M.C. Ramadevi V.C. Babu M.R. Sharma N.S.R. Murthy B.N. Ashoka K.C. Shyama R. Kulkarni G. Meena P. Sreekumar 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2995-2998
The Scanning Sky Monitor is one of the experiments onboard the ASTROSAT, an Indian multiwavelength astronomy satellite mission. This experiment will detect and monitor X-ray transients in the energy band 2–10 keV. It is similar in design to the ASM on RXTE. It consists of position-sensitive proportional counters with one-dimensional mask. We describe the configuration of the experiment. We also discuss some of the results obtained using a detector which has already been fabricated and tested in our laboratory. 相似文献
292.
293.
Information Support for Space Experiments Based on a Numerical-Analytical Theory of Satellite Motion
A software tool for application in calculations of the position and velocity vectors of spacecraft is presented. These vectors are necessary at the stage of processing the data of space experiments and analyzing the results of ground-based observations. A new theory of satellite motion, in a numerical-analytical form, is the basis of this software application. The model of disturbing forces corresponds to recommendations of the International Laser Ranging Service. The reliability of the software tool is confirmed by the results of processing of high-precision laser satellite observations. 相似文献
294.
Oxygen Isotopes in the Solar System 总被引:1,自引:0,他引:1
The oxygen three-isotope system has major advantages over the two-isotope systems of hydrogen, carbon, and nitrogen because
different fractionation laws govern intraplanetary and interplanetary processes. This permits discriminating between solar
nebular processes and parent-body processes. Oxygen isotopes also serve as a sensitive natural tracer for meteorite classification.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
295.
Battery charger design for the Columbus MTFF power system 总被引:1,自引:0,他引:1
van Dijk K. Klaassens J.B. Spruijt H.J.N. O'Sullivan D.M. 《IEEE transactions on aerospace and electronic systems》1997,33(1):29-37
A novel pulsewidth-modulated (PWM) dc-dc converter topology is proposed for the battery charge regulator (BCR) of the Columbus Man-Tended Free-Flyer (MTFF) power system. The system is a regulated bus system. Bus voltage control is implemented at the input of the BCR. The use of a conventional buck topology with PWM conductance control at the input results in a second-order behavior. A study of new PWM dc-dc converter topologies has been made to attain a suitable topology. The proposed converter topology is designed and a breadboard including the control loop has been built and tested. The experimental results show that the converter operates according to the design constraints. 相似文献
296.
T G Guzik S Albergo C X Chen S Costa H J Crawford J Engelage P Ferrando I Flores L Greiner F C Jones C N Knott S Ko P J Lindstrom J Mazotta J W Mitchell J Romanski R Potenza A Soutoul O Testard C E Tull C Tuve C J Waddington W R Webber J P Wefel X Zhang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1994,14(10):825-830
The Transport Collaboration, consisting of researchers from institutions in France, Germany, Italy and the USA, has established a program to make new measurements of nuclear interaction cross sections for heavy projectiles (Z > or = 2) in targets of liquid H2, He and heavier materials. Such cross sections directly affect calculations of galactic and solar cosmic ray transport through matter and are needed for accurate radiation hazard assessment. To date, the collaboration has obtained data using the LBL Bevalac HISS facility with 20 projectiles from 4He to 58Ni in the energy range 393-910 MeV/nucleon. Preliminary results from the analysis of these data are presented here and compared to other measurements and to cross section prediction formulae. 相似文献
297.
P. Ubertini A. Bazzano L. Boccaccini N.A. Dipper L. Iafrate C. LaPadula M. Mastropietro R. Patriarca V. Polcaro M.L. Urciuoli 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(1):105-108
A new design of position sensitive spectroscopic proportional counter is described, for use in a balloon borne hard x-ray telescope. Initial position and spectral resolution data from a one-dimensional laboratory prototype are reported. With this device, the final telescope will have an angular resolution of better than 10 minutes of arc. 相似文献
298.
R Tixador G Richoilley G Gasset H Planel N Moatti L Lapchine L Enjalbert J Raffin R Bost S N Zaloguev M P Bragina A F Moroz N G Antsiferova F M Kirilova 《Acta Astronautica》1985,12(2):131-134
Cytos 2 experiment, carried out during the French-Soviet manned flight (July 1982), has studied the antibiotics sensitivity of bacteria cultivated in vitro during the orbital flight. The results show an increase of the antibiotics resistance and a larger thickness of the cellular envelope for the inflight cells. The increase of antibiotics resistance can be related to a stimulating effect of space on the cell growth rate or to changes of the cellular envelope structure. 相似文献
299.
T.K. Yeoman H.C. Scoffield D.M. Wright L.J. Baddeley A.N. Vasilyev N.V. Semenova 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
A brief review is provided of recent progress in understanding the ionospheric Alfvén resonator (IAR) at high latitude. Firstly, naturally occurring resonances of the IAR as detected by pulsation magnetometers in the auroral zone at Sodankylä and in the polar cap at Barentsburg are considered. The characteristics of the IAR in the two regions are broadly similar, although the effects of solar illumination are less clear at the higher latitudes. Secondly we review recent attempts to stimulate the IAR through high-power radio frequency experiments both in the auroral zone at Tromsø with the European Incoherent SCATter (EISCAT) heater, and within the polar cap at Longyearbyen with the Space Plasma Exploration by Active Radar (SPEAR) facility. In the auroral zone at, Tromsø the stimulated IAR has been observed by ground-based magnetometers, and through electron acceleration observed on the FAST spacecraft. At SPEAR in the polar cap, the stimulated IAR has been investigated, with ground magnetometers, with the first results indicative of a positive detection. 相似文献
300.
B.F. Gordiets Yu.N. Kulikov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(9):113-117
The plausible mechanisms of cooling of the nightside Venus' thermosphere are analysed with the aid of the model of the atmospheric heat budget that incorporates, in addition to thermal conduction and IR radiation in the 15 μ band of CO2, heating and cooling due to global scale winds, eddy turbulence, and IR radiation in the rotational bands of H2O and CO, as well as the 63 μ line of atomic oxygen. The H2O mixing ratio and parameters of turbulence required for cooling of the thermosphere down to the observed low temperatures are evaluated. 相似文献