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美国联邦航空局(FAA)已批准空中客车工业公司的计划,允许民航公司使用同一组驾驶员飞行A320、A330和A340飞机。 据空中客车讲,这一计划可使空中客车的用户比其他飞机的用户每年减少上百万美元的培训和管理费用。费用节省来自机组生产率和模拟器的选择,模拟器可以转用于不同机型的驾驶员训练。而且这一计划还有助于远程飞机驾驶员熟练掌握关键飞行阶段技术,如着陆,因为他们可以同时飞行起落频繁的短程航线,进而可以提高飞行安全。民航飞行员协会和航空安全官员担心“混合机队”飞行计划的批准会使驾驶员因需掌握不同型号飞机的结构和性能而负担过重。 相似文献
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In Space many bodily functions adjust to the absence of gravity. Our understanding of these homeostatic processes have depended on studies on man and other animals. The present paper briefly reviews how such studies may benefit some terrestrial medical problems. 相似文献
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Sinyak Y Grigoriev A Gaydadimov V Gurieva T Levinskih M Pokrovskii B 《Acta Astronautica》2003,52(7):575-580
Heavy water containing deuterium displays toxic property. It is stated that any quantity of a heavy isotope of hydrogen--deuterium--is undesirable to animals and plants. It was earlier shown by us that physical-chemical life support systems on board the "MIR" station fractionate (change) isotopes of hydrogen, oxygen and carbon. Therefore, the problem of regenerative systems in habitable space objects should include removal, from water, of a heavy stable isotope of hydrogen--deuterium. In this article we consider one method of obtaining deuterium-free water--decomposition of distillate water in an electrolyser to hydrogen and oxygen with subsequent synthesis in a catalytic or high-temperature reactor. The influence of deuterium-free water on the growth and development of Arabidopsis thaliana and Japanese quail is investigated. It is shown that with the help of the electrolysis method it is possible to fabricate water containing 80% less deuterium in comparison with SMOW. Experimentally, it is proved on a culture of Arabidopsis thaliana and Japanese quail that water with reduced contents of deuterium (80%) displays positive biological activity. 相似文献
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The principal goal of the NASA Terrestrial Planet Finder (TPF) and European Space Agency's Darwin mission concepts is to directly detect and characterize extrasolar terrestrial (Earthsized) planets. This first generation of instruments is expected to provide disk-averaged spectra with modest spectral resolution and signal-to-noise. Here we use a spatially and spectrally resolved model of a Mars-like planet to study the detectability of a planet's surface and atmospheric properties from disk-averaged spectra. We explore the detectability as a function of spectral resolution and wavelength range, for both the proposed visible coronograph (TPFC) and mid-infrared interferometer (TPF-I/Darwin) architectures. At the core of our model is a spectrum-resolving (line-by-line) atmospheric/surface radiative transfer model. This model uses observational data as input to generate a database of spatially resolved synthetic spectra for a range of illumination conditions and viewing geometries. The model was validated against spectra recorded by the Mars Global Surveyor-Thermal Emission Spectrometer and the Mariner 9-Infrared Interferometer Spectrometer. Results presented here include disk-averaged synthetic spectra, light curves, and the spectral variability at visible and mid-infrared wavelengths for Mars as a function of viewing angle, illumination, and season. We also considered the differences in the spectral appearance of an increasingly ice-covered Mars, as a function of spectral resolution, signal-to-noise and integration time for both TPF-C and TPFI/ Darwin. 相似文献