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931.
E A Krasavin S Kozubek K G Amirtayev B Tokarova M Bonev 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(2-3):103-110
The peculiarities and mechanisms of the mutagenic action of gamma-rays and heavy ions on bacterial cells have been investigated. Direct mutations in the lac-operon of E. coli in wild type cells and repair deficient strains have been detected. Furthermore, the induction of revertants in Salmonella tester strains was measured. It was found that the mutation rate was a linear-quadratic function of dose in the case of both gamma-rays and heavy ions with LET up to 200 keV/micrometer. The relative biological effectiveness (RBE) increased with LET up to 20 keV/micrometer. Low mutation rates were observed in repair deficient mutants with a block of SOS-induction. The induction of SOS-repair by ionizing radiation has been investigated by means of the "SOS-chromotest" and lambda-prophage induction. It was shown that the intensity of the SOS-induction in E. coli increased with increasing LET up to 40-60 keV/micrometer. 相似文献
932.
A M Alpatov V V Antipov M G Tairbekov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(1):27-32
In order to reveal the biological significance of gravity, microgravity effects have been studied at the cellular, organism and population levels. The following questions arise. Do any gravity-dependent processes exist in a cell? Is cell adaptation to weightlessness possible; if so, what role may cytoskeleton, the genetic apparatus play in it? What are the consequences of the lack of convection in weightlessness for the performance of morphogenesis? Do the integral characteristics of living beings change in weightlessness? Is there any change in "biological capacity" of space, its resistance to expansion of life? What are the direction and intensity of microgravity action as a factor of natural selection, the driving force of evolution? These problems are discussed from a theoretical point of view, and in the light of results obtained in experiments from aboard biosatellites "Cosmos". 相似文献
933.
934.
R.A. Gowen A. Smith A.D. Fortes S. Barber P. Brown P. Church G. Collinson A.J. Coates G. Collins I.A. Crawford V. Dehant J. Chela-Flores A.D. Griffiths P.M. Grindrod L.I. Gurvits A. Hagermann H. Hussmann R. Jaumann A.P. Jones K.H. Joy O. Karatekin K. Miljkovic E. Palomba W.T. Pike O. Prieto-Ballesteros F. Raulin M.A. Sephton S. Sheridan M. Sims M.C. Storrie-Lombardi R. Ambrosi J. Fielding G. Fraser Y. Gao G.H. Jones G. Kargl W.J. Karl A. Macagnano A. Mukherjee J.P. Muller A. Phipps D. Pullan L. Richter F. Sohl J. Snape J. Sykes N. Wells 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
935.
A. L. Tukmakov V. G. Tonkonog A. G. Kochenkov S. A. Kusyumov 《Russian Aeronautics (Iz VUZ)》2011,54(4):402-411
A physical and mathematical model of a boiling-up fluid flow in the variable crosssection channels is proposed. The numerical
model is based on the solution of the Navier-Stokes nonstationary equations for compressible fluid by the implicit finite-difference
method. We present the results of the numerical modeling for two-phase flow characteristics at the initial stage of the evaporation
process and the steady-state quasistationary flow of a two-phase medium. 相似文献
936.
A. V. Bykov G. V. Kondrashev S. G. Parafes’ I. K. Turkin 《Russian Aeronautics (Iz VUZ)》2016,59(3):331-337
Theoretical and experimental methods of investigating the performance of an electric actuator of maneuverable unmanned aerial vehicle (UAV) is considered in order to solve the aeroelasticity tasks. Models of the stability analysis for the rudder–actuator system as well as the examples of numerical and experimental studies of this system performance are given. 相似文献
937.
D. J. McComas E. R. Christian N. A. Schwadron N. Fox J. Westlake F. Allegrini D. N. Baker D. Biesecker M. Bzowski G. Clark C. M. S. Cohen I. Cohen M. A. Dayeh R. Decker G. A. de Nolfo M. I. Desai R. W. Ebert H. A. Elliott H. Fahr P. C. Frisch H. O. Funsten S. A. Fuselier A. Galli A. B. Galvin J. Giacalone M. Gkioulidou F. Guo M. Horanyi P. Isenberg P. Janzen L. M. Kistler K. Korreck M. A. Kubiak H. Kucharek B. A. Larsen R. A. Leske N. Lugaz J. Luhmann W. Matthaeus D. Mitchell E. Moebius K. Ogasawara D. B. Reisenfeld J. D. Richardson C. T. Russell J. M. Sokół H. E. Spence R. Skoug Z. Sternovsky P. Swaczyna J. R. Szalay M. Tokumaru M. E. Wiedenbeck P. Wurz G. P. Zank E. J. Zirnstein 《Space Science Reviews》2018,214(8):116
The Interstellar Mapping and Acceleration Probe (IMAP) is a revolutionary mission that simultaneously investigates two of the most important overarching issues in Heliophysics today: the acceleration of energetic particles and interaction of the solar wind with the local interstellar medium. While seemingly disparate, these are intimately coupled because particles accelerated in the inner heliosphere play critical roles in the outer heliospheric interaction. Selected by NASA in 2018, IMAP is planned to launch in 2024. The IMAP spacecraft is a simple sun-pointed spinner in orbit about the Sun-Earth L1 point. IMAP’s ten instruments provide a complete and synergistic set of observations to simultaneously dissect the particle injection and acceleration processes at 1 AU while remotely probing the global heliospheric interaction and its response to particle populations generated by these processes. In situ at 1 AU, IMAP provides detailed observations of solar wind electrons and ions; suprathermal, pickup, and energetic ions; and the interplanetary magnetic field. For the outer heliosphere interaction, IMAP provides advanced global observations of the remote plasma and energetic ions over a broad energy range via energetic neutral atom imaging, and precise observations of interstellar neutral atoms penetrating the heliosphere. Complementary observations of interstellar dust and the ultraviolet glow of interstellar neutrals further deepen the physical understanding from IMAP. IMAP also continuously broadcasts vital real-time space weather observations. Finally, IMAP engages the broader Heliophysics community through a variety of innovative opportunities. This paper summarizes the IMAP mission at the start of Phase A development. 相似文献
938.
A. A. Vostrukhin D. V. Golovin A. S. Kozyrev M. L. Litvak A. V. Malakhov I. G. Mitrofanov M. I. Mokrousov T. M. Tomilina Yu. I. Bobrovnitskiy A. S. Grebennikov M. M. Laktionova B. N. Bakhtin A. V. Sotov 《Cosmic Research》2018,56(3):208-212
The results of testing a number of space-based detectors that contain PMTs or high-voltage electrodes for the noise from the microphonics that occurs in the signal path due to external mechanical action have been presented. A method for the vibration isolation of instruments aboard a spacecraft has been proposed to reduce their responsivity to vibrations. 相似文献
939.
The equations of the mathematical model are solved in terms of special functions. The results for the design scheme of the aircraft forebody are obtained with a guaranteed accuracy by the stable method of functional normalization. 相似文献
940.
Space Science Reviews - The NRL ionosphere/plasmasphere model SAMI3 has been modified to support the NASA ICON mission. Specifically, SAMI3_ICON has been modified to import the thermospheric... 相似文献