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911.
A.V Yakovenko 《Space Policy》2000,16(1):39
Despite its straightened circumstances and doubts about how much political support it receives, Russia's space programme continues — and continues to plan for new activities and applications. This edited version of the National Paper of the Russian Federation, presented at Unispace III in July 1999, details some of the country's major achievements in space in recent years and sets out the main areas it intends to pursue for the early twentieth-first century. While emphasis is placed on communications, remote sensing, navigation and space science, the commitment to manned flight remains. 相似文献
912.
L Y Popova T I Lobova T Y Krylova T V Kargatova E E Maksimova A N Boyandin N S Pechurkin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2001,27(9):1571-1579
The role of key environmental factors in adaptation of spore-forming and non-spore-forming transgenic microorganisms (TM) have been studied in model ecosystems. Model TM Escherichia coli Z905 (bearing plasmid genes of bacterial luminescence Ap (r) Lux+) has been found to have a higher adaptation potential than TM Bacillus subtilis 2335/105 (bearing genes of human alpha 2-interferon Km (r) Inf+), planned for employment as a living vaccine under varying environmental conditions. Effects of abiotic factors on migration of natural and recombinant plasmids between microorganisms under model ecosystem conditions has been estimated. The transgenic microorganisms with low copy number survived better under introduction conditions in the microcosms studied. This trend has been shown to be independent of the microcosm type and its complexity. Grant numbers: 99-04-96017, 25, 00-07-9011. 相似文献
913.
In radar systems, extended Kalman-Bucy filters (EKBFs) are used to estimate state vectors of objects in track. Filter models accounting for fundamental aerodynamic forces on reentry vehicles are well known. A general model structure accommodating the dynamics of reentry vehicles in both exoatmospheric and endoatmospheric flight is presented. The associated EKBFs for these various models are described and the resulting associated parameter estimation and identification problems are discussed. The effects of position, velocity, drag, and aerodynamic lift are described within a nested set of EKBF models 相似文献
914.
915.
The enhancements of solar protons with an energy of more than 30 MeV, originating from flares in one active region and observed simultaneously aboard three spacecraft Vega-1, 2 and Prognoz-10 in July 1985, are analyzed and approximated in this work by using the reflection model [2]. The numerical values of several physical parameters (the parameters of distribution of solar cosmic ray (SCR) particles inside heliosphere traps, the coefficients of trap transparency) that are not observed by direct measurements are estimated. 相似文献
916.
A discussion of the current and emerging core technologies and philosophies that will enable Air Force personnel to quickly, accurately and intuitively diagnose faults in increasingly complex systems 相似文献
917.
V Ostroumov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1995,15(3):229-236
Data from experiments with model samples show that ion transfer coefficients in the water-rich permafrost on Mars must be three orders of magnitude less than those of terrestrial permafrost. The effects of low temperatures and of carbon dioxide have been accounted for. Exchange between cells and the environment is impeded in Martian permafrost. The microscopic distributional heterogeneity of concentration, pH, Eh, and other physicochemical parameters may be more pronounced in the permafrost of Mars. We present a classification of unfrozen water types in the permafrost that is based on the structures of unfrozen water films and on their functions with respect to cells. Any viable microorganisms on Mars probably exist with minimum metabolism in compact zones with energy carriers and high transfer coefficients. These zones may be microvolumes of unfrozen water in which cells accumulate. 相似文献
918.
Angle glint can be explained as distortions in the radar echo signal phase front, or alternatively, deviations of the direction of power flow from the radial direction. Here we show that these two theories yield identical results when the polarization of the scattered waves and the receiving antenna are considered. 相似文献
919.
D. V. Titov H. Svedhem D. McCoy J. -P. Lebreton S. Barabash J. -L. Bertaux P. Drossart V. Formisano B. Haeusler O. I. Korablev W. Markiewicz D. Neveance M. Petzold G. Piccioni T. L. Zhang F. W. Taylor E. Lellouch D. Koschny O. Witasse M. Warhaut A. Acomazzo J. Rodrigues-Cannabal J. Fabrega T. Schirmann A. Clochet M. Coradini 《Cosmic Research》2006,44(4):334-348
The first European mission to Venus (Venus Express) is described. It is based on a repeated use of the Mars Express design with minor modifications dictated in the main by more severe thermal environment at Venus. The main scientific task of the mission is global exploration of the Venusian atmosphere, circumplanetary plasma, and the planet surface from an orbiting spacecraft. The Venus Express payload includes seven instruments, five of which are inherited from the missions Mars Express and Rosetta. Two instruments were specially designed for Venus Express. The advantages of Venus Express in comparison with previous missions are in using advanced instrumentation and methods of remote sounding, as well as a spacecraft with a broad spectrum of capabilities of orbital observations. 相似文献
920.
The motion of a spacecraft (SC) with double rotation and variable mass on the active leg of its descent is considered. The SC consists of two coaxial bodies. The coaxial scheme is used for gyroscopic stabilization of the SC longitudinal axis by the method of partial spin-up. The equations of spatial motion of coaxial bodies of varying composition are derived and approximate solutions for the angles of spatial orientation are found. The condition of decreasing amplitude of nutation oscillations is obtained, which allows the estimation of efficiency of the stabilization by partial spin-up. The errors in the magnitude and direction of the vector of braking thrust are also determined.__________Translated from Kosmicheskie Issledovaniya, Vol. 43, No. 3, 2005, pp. 224–232.Original Russian Text Copyright © 2005 by Aslanov, Doroshin, Kruglov. 相似文献