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471.
Hamlen R.P. Hoge W.H. Hunter J.A. O'Callaghan W.B. 《Aerospace and Electronic Systems Magazine, IEEE》1991,6(10):11-14
Advances in aluminum-air batteries are described. These include alloys that show higher efficiencies and therefore lower hydrogen evolution, low-cost air cathodes that can be fabricated in production quantities, and methods for handling the aluminum hydroxide reaction product. Emphasis is placed on the advances in air cathodes. The application of this technology to new products and the implications for electric vehicles are discussed 相似文献
472.
Smart M.C. Ratnakumar B.V. Whitcanack L. Chin K. Rodriguez M. Surampudi S. 《Aerospace and Electronic Systems Magazine, IEEE》2002,17(12):16-20
The low temperature charge and discharge characteristics of experimental MCMB-Li/sub x/Ni/sub y/Co/sub 1-y/O/sub 2/ cells containing different electrolytes were investigated. The use of low ethylene carbonate (EC)-content electrolyte formulations has resulted in good discharge performance to temperatures as low as -40/spl deg/C. The effect of charge voltage and charge current upon the individual electrode potentials at low temperature was investigated using the three electrode cells (containing lithium reference electrodes). In some cases, lithium plating was observed to occur upon low temperature charge, and found to be facilitated by high charge voltages, high charge currents, and poor anode kinetics. Electrochemical characterization of the cells has helped to establish the conditions under which lithium plating can occur by providing information regarding the polarization effects present at each electrode. 相似文献
473.
S. I. Avdyushin M. B. Belotserkovsky V. Kim A. S. Koroteev A. M. Kulikov A. I. Livshits Yu. K. Melnikov R. I. Moisya N. N. Petrov H. A. Popov Yu. A. Romanovsky Yu. A. Utkin V. V. Chilap 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(12):163-167
Results of rocket experiments on study of plasma flows (PF) artificially injected by sources separated from vehicles and their effect on medium parameters in ionosphere at altitudes 160:230 km are presented.PF were injected comprising lithium ions with velocities 1,2 x 104 m/sec. and cesium-potassium ions with velocities (1,4–1,5)x103 m/sec. Mass flow rate in case of lithium PS is 2 mg/sec, and in case of cesium-potassium PS is 0,2 g/sec. During experiments mass-spectrometer measurements of ion medium content in ranges of different ion masses were held, disturbancies of electric fields with frequencies up to 20 kHz and electron flows with energies 0,7keV, 4,6keV and over 40 keV were controlled at distancies from 150m to (500–600)m between plasma source and scientific equipment. 相似文献
474.
Dias J.M.B. Marques P.A.C. 《IEEE transactions on aerospace and electronic systems》2003,39(2):604-624
A novel methodology is presented for determining the velocity and location of multiple moving targets using a single strip-map synthetic aperture radar (SAR) sensor. The so-called azimuth position uncertainty problem is therefore solved. The method exploits the structure of the amplitude and phase modulations of the returned echo from a moving target in the Fourier domain. A crucial step in the whole processing scheme is a matched filtering, depending on the moving target parameters, that simultaneously accounts for range migration and compresses two-dimensional signatures into one-dimensional ones without losing moving target information. A generalized likelihood ratio test approach is adopted to detect moving targets and derive their trajectory parameters. The effectiveness of the method is illustrated with synthetic and real data covering a wide range of targets velocities and signal-to-clutter ratios (SCRs). Even in the case of parallel to platform moving target motion, the most unfavorable scenario, the proposed method yields good results for, roughly, SCR > 10 dB. 相似文献
475.
An overview of military avionics data buses and their applications, with the emphasis on optical fiber networking techniques. The evolution of military avionics data buses is discussed. The development trend actually reflects an increasing demand on such data buses, which requires the change from low-speed to high-speed transmissions, from single-rate to dual-rate operations, and from centralized control to distributed control. Recent progress in military avionics networks is described. 相似文献
476.
V V Akatov YuAArkhangelsky A P Aleksandrov I Feher S Deme B Szabo J Vagyolgyi P P Szabo A Csoke M Ranky B Farkas 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(10):77-81
A small, vibration- and shock-resistant thermoluminescent dosemeter /TLD/ system--named PILLE--was developed at the Health Physics Department of the Central Research Institute for Physics, Budapest, to measure the cosmic radiation dose on board orbital stations. The first on-board measurements with this system were performed /by B. Farkas, the Hungarian astronaut/, on the Salyut-6 space station in 1980. The same instrument was used by other crews in the following years. Doses measured at different sites in Salyut-6 are presented. The dose rates varied from 0.07 to 0.11 mGy.day-1. After the first cosmic measurements, the system was further developed. The minimum detectable dose of the new TLD system is 1 microGy, i.e. less by on order of magnitude than that of the former system. The self-irradiation dose rate of the TLD bulbs is also reduced--by more than one order of magnitude--to 10 nGy.h-1, by the use of potassium-free glass for the bulb envelope. This new type of PILLE TLD system is currently on-board Salyut-7. The dose rates /0.12-0.23 mGy.day-1/ measured in 1983 are presented in detail. 相似文献
477.
S.M. Siegel B.Z. Siegel 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(9):135-139
Beyond their role in the cycling of the major elements, carbon, nitrogen, oxygen, etc., little is known about geobiological interactions involving plants with the elements of lower abundance. Plants influence the distribution of volcanic mercury by uptake from the atmosphere and soil fluids, transport to the shoot and re-release as Hg° into the atmosphere. Release rates as high as 2.5 × 10?4 g.h?1 per kg are known but even at more typical rates, fluxes far greater than the Environmental Protection Agency calculated U.S. average annual degassing rate of 130 × 10?6 g.m?2 should exist. On a global basis, the presence or absence of vegetative cover may be a significant regulator of Hg° transport between land surfaces and the atmosphere. 相似文献
478.
479.
M.M. Gogoshev B.P. Komitov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(8):155-160
In this paper the latest neutral and ionospheric models of the upper Martian atmosphere, created on the Viking data are used. For the calculations of the photoelectron spectra the Hinteregger's measurements of the solar flux together with the theoretical photoelectron distribution are also used. 相似文献
480.