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971.
V.V. Belgiy V.V. Bugrovskiy Yu.V. Kovachich B.N. Petrov A.A. Shevyakov 《Acta Astronautica》1981,8(1):67-78
Diagnosis of a space thermoemission power unit incorporating a Topaz type reactor converter is hindered by the low potential of the measurement system. The lack of information is restored by computing from the measurement date. Examples of dynamic mode diagnosis with restoration of information on the field temperature is given. The power unit diagnosis algorithms are implemented in the onboard computer whose power is about 200,000 operations per second. Memory and computing requirements are determined from algorithms of different diagnosis degrees. Results in study of the necessary computer component redundancy are given for different models of system degradation. The redundancy level should insure that the nucleus of the computer system with a minimally necessary 4K-words memory remains in operation after three years into the mission. 相似文献
972.
J. B. Hutchings 《Space Science Reviews》1980,26(3):331-345
The review is a discussion of observationally deduced values of the masses, mass-loss rates, temperatures, luminosities and element abundances for the most massive stars. The comparison of these quantities with theoretical calculations is also discussed, in terms of our present understanding of their evolution. 相似文献
973.
A lower bound exists for the accuracy with which the future position of a randomly accelerating target can be predicted. This bound applies even when noiseless data is optimally processed. In this correspondence, the prediction error bound is evaluated and presented as a universal curve for the case of a stationary random acceleration process with an exponential autocorrelation function. 相似文献
974.
975.
Masserant B.J. Stuart T.A. 《IEEE transactions on aerospace and electronic systems》1997,33(3):930-938
A battery charger is described that uses an on-line microcontroller to maximize its output power. This is done by always operating at either the maximum allowable input current or the thermal limit imposed by the charger itself. In this case the thermal limit is determined by the junction temperatures of the two main insulated gate bipolar transistors (IGBTs). Since direct measurement of these temperatures is impractical, they must be calculated by a computer algorithm that uses various on-line measurements. Experimental results for an 8 kW charger indicate a reduction in the bulk charging time of about 26% when used with a set of NiFe batteries. 相似文献
976.
B.N. Dwivedi Anita Mohan P.K. Raju 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1997,20(12):2271-2274
We present NeV/MgV and MgVII/SiVII theoretical line intensity ratios as a function of electron density and temperature for physical conditions within the solar chromosphere-corona transition region. The electron pressure within the emission regions has been assumed to be a constant parameter. These line intensity ratios in addition could be useful for estimating relative element abundances Ne/Mg and Mg/Si. Line intensities of these ions have been computed using a model solar atmosphere and these have been compared with the available observed values for the quiet -Sun conditions. The analysis suggests the need for observations at higher spectral resolution. The successful launch of the SOHO satellite recently should provide such spectra. 相似文献
977.
M B Simakov E A Kuzicheva A E Dodonova NYaAntropov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1997,19(7):1063-1066
The present experiment indicates that oligopeptides are easily produced in solid state from mixtures of simple amino acids by irradiating with high energy charged particles. We investigated such amino acids and their mixtures as tryptophan, tyrosine and glycine. The thin films was irradiated with protons (6.6 MeV). Such dipeptides as Trp-Trp, Gly-Tyr, Tyr-Gly, and Tyr-Tyr have been detected as products of irradiation. Cosmic rays might be an effective energy source for abiotic formation of bioorganic compounds on the surface of small bodies in the solar system on early stage of formation of planets as well as at present day. 相似文献
978.
G. Courtès M. Golay M. Viton W. Bentz J.M. Deharveng M. Laget J. Donas J.P. Sivan B. Milliard 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(11):81-88
The use of the 2 000 Å transmission window of the atmosphere permitted to observe for the first time from a balloon gondola the nearest galaxies ; 30 arc/sec. resolution images were obtained for M 31, spiral arms and nucleus, M 33, M 101, with their external spiral structure, M 82 and NGC 3 077. Nearly three hundred more distant galaxies have been detected up to the magnitude V = 13. Several HII regions of the Galaxy have been observed, chiefly NGC 7 000 and the Cyghus Loop. Numerous blue stars of the halo have been identified. 相似文献
979.
R.A. Harrison A. Fludra E.C. Sawyer J.L. Culhane K. Norman A.I. Poland W.T. Thompson O. Kjeldseth-Moe B. Aschenbach M.C.E. Huber A.H. Gabriel H.E. Mason 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1997,20(12):2239-2248
We present first results from the Coronal Diagnostic Spectrometer (CDS) aboard the ESA/NASA Solar and Heliospheric Observatory (SOHO). CDS is a double spectrometer operating in the 151–785 Å range. This region of the solar spectrum is rich in emission lines from trace elements in the solar atmosphere, which can be used to derive diagnostic information on coronal and transition region plasmas. Early spectra are presented and well identified lines are listed. In addition, examples of images in selected wavelength ranges are shown, for a prominence, a loop system and a bright point, demonstrating well the power of such extreme ultraviolet observations. 相似文献
980.
Space Science Reviews - 相似文献