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831.
R. Baker A.J. Dean N. Dipper R.A. Lewis D. Ramsden G. Barbaglia G. Boella A. Bussini A. Carzaniga G. Ferrandi D. Maccagni F. Perotti M. Quadrini R. Santambrogio G. Villa A. Bazzano L. Boccaccini C. La Padula P. Ubertini 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(4):83-85
A balloon-borne multitechnique large area experiment consisting of 2 co-aligned detectors (3200 cm2 NaI and 1800 cm2 multiwire proportional counters), is described, which is capble of producing observations of the hard X-ray sky with very high sensitivity and good spectral resolution over the whole operative range (15–300 keV). 相似文献
832.
The dynamics of formation of the ordered structures of charged macroparticles under microgravity conditions is investigated. The experimental observations of the behavior of an ensemble of macroparticles were carried out onboard the Mirspace station. The analysis and comparison of results of experimental and theoretical investigations allow us to conclude that under microgravity conditions the formation of elongated, ordered structures of macroparticles, charged by solar radiation, is possible. 相似文献
833.
One of the main goals in transforming the Army is the process of moving away from the use of paper maps and grease pencils into more embedded and computer-oriented forms of command and control. There are currently many weapons platforms trying to achieve this function; however, each platform is developing their own solution to meet individual needs. The Army as a whole needs to standardize on a single path forward to ensure that all systems can communicate across the digitized battlefield, allow for each platform to have a "common picture," and promote software reuse across the Army. Once this "common picture" is achieved, the armed forces will have the information needed to continue domination of the battlefield. 相似文献
834.
Papa R.J. Lennon J.F. Taylor R.L. 《IEEE transactions on aerospace and electronic systems》1983,(4):585-597
The first topic considered is an analysis of the conditions under which the conventional definition of length of the glistening surface, as given by Beckmann and Spizzichino, is not valid. For some conditions, significant amounts of incoherent scattered power can be received from areas beyond the conventional length. A second topic is the investigation of the effect on azimuthal angular tracking accuracy due to such scattering factors as shadowing, surface height distribution, standard deviation in surface height ?, surface correlation length T, unevenness and inhomogeneity of the terrain, antenna heights, and signal polarization. A number of interesting results have been observed. The amount of additional incoherent power not included under the conventional definition depends on the ratio ?/T, except for the case where both transmitter and receiver are very close to the surface. The trends in the behavior of the glistening surface are similar for vertical or horizontal polarization, for Gaussian or exponential surface height distributions, and for different signal frequencies in the S-band to L-band range. 相似文献
835.
R.C. Butler E. Caroli O. Catani G. Di Cocco E. Morelli A. Rubini G. Spada A. Traci L. Barbareschi A. Igiuni M. Santini G. Villa A. Bazzano C. La Padula F. Polcaro P. Ubertini R.E. Baker J.N. Carter D. Ramsden 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(4):95-98
A large area (6000 cm2) actively shielded low energy gamma-ray telescope is going to be built by an Anglo-Italian collaboration. The telescope, named ZEBRA, will be capable of producing images of the X and gamma ray sky in the energy range 0.015–20 MeV with an intrinsic angular resolution of a few tenths of a degree. A prototype detector has been built in order to experimentally study the main characteristics of the detection plane. The preliminary results obtained during a balloon flight from Trapani, Sicily in July 1981 are presented. 相似文献
836.
L. Barbareschi C. La Padula M. Mastropietro F. Perotti G. Villa A. Bazzano L. Boccaccini R. Patriarca V.F. Polcaro P. Ubertini R.C. Butler G. Di Cocco G. Spada J.N. Carter P. Charalambous A.J. Dean J.B. Stephen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(4):91-93
In order to improve the low energy capability (15 ÷ 150 KeV) of the balloon borne “ZEBRA” low energy gamma imaging telescope (150 KeV-20 MeV), a large area, high spectral resolution (5% at 60 KeV), low background detector has been designed and is now under development.It consists of two MultiWire Spectroscopic Proportional Counter (SPC), escape gated, that have a sensitive area of 6000 cm2, and are placed above the large area array of sodiumiodide position sensitive elements. 相似文献
837.
Lawrence C. Rowan Alexander F.H. Goetz Marguerite J. Kingston 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(2):125-132
The Shuttle Multispectral Infrared Radiometer (SMIRR) is a spectroradiometer covering the region from 0.5 to 2.5 μm in 10 channels that acquired data from spots 100 m in diameter along the subspacecraft ground track. It was flown aboard the second flight of the space shuttle Columbia, November 12–14, 1981. Data collected during orbit 16 over southern Egypt show that carbonate rocks, kaolinite, and possibly montmorillonite can be identified by their SMIRR spectral signatures and limited knowledge of the lithologic units present. Detailed analysis of SMIRR data for this area indicates that calcite, kaolinite, and montmorillonite rocks give rise to absorption features that result in characteristic 10 channel spectra. 相似文献
838.
An MHD converter using a mixture of metal in liquid and a metallic vapor should prove very efficient due to its high conductivity, and should function at relatively low temperatures. An experimental apparatus is being tested at the Grenoble Institute. 相似文献
839.
F.L. Scarf D.A. Gurnett W.S. Kurth R.L. Poynter 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1987,7(12):253-258
At Uranus, the Voyager 2 plasma wave investigation observed very significant phenomena related to radio emissions, dust impacts and magnetospheric wave-particle interactions. On January 19, 1986 (R= 270RU) the plasma wave investigation detected an intense radio burst at 31 and 56 kHz, and this provided the first indication that Uranus had a magnetosphere. During the encounter we observed more of these sporadic bursts, along with relatively continuous radio emissions extending down to 10 kHz, and a sporadic narrowband radio signal with f near 5 kHz. As Voyager passed through the ring plane, the plasma wave investigation recorded a large number of dust impacts. The dust ring was relatively diffuse (thickness of several thousand kilometers) and the peak impact rate was near 50 hits/second. The Voyager 2 plasma wave instrument also detected many strong electromagnetic and electrostatic plasma waves, with intensity peaks in the region within 12 Uranus adii. These waves have characteristics that can interact strongly with the local plasma and with the trapped energetic particles, leading to precipitation into the atmosphere, charged particle acceleration, and charged particle diffusion. In addition we detected strong wave activity in the region of the bow shock and moderate levels in the magnetic tail. 相似文献
840.
L.K. Harra-Murnion S.P. Plunkett S.F. Helsdon K.J.H. Phillips L. Van Driel-Gesztelyi B. Schmieder B. Rompolt M. Akioka 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1997,20(12):2333-2336
Yohkoh has observed many long duration events permitting a statistical study of the properties of these interesting events. We have selected ten flares for analysis which have durations between 5 and 20 hours, and size ranging from C to X GOES class. Employing the Soft X-ray Telescope, the Bragg Crystal Spectrometer, GOES spacecraft, and ground-based H data, we examine the morphology, temperature, emission measure, location of the hard X-ray source, non-thermal velocities and upflows of the plasma at different stages in the flare development. Our results are used to address the question of the energy source that maintains the hot plasma at temperatures of several million degrees for many hours. 相似文献