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351.
N. F. Blagoveshchenskaya T. D. Borisova O. V. Kolosov V. A. Kornienko 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1995,15(12):111-114
Results of experimental studies of the ionospheric effects produced by CRRES barium releases are considered. The experimental observations of HF spectral characteristics by Doppler method are made by a network of long distance radio paths intersecting the L-shell of releases. The time dependence of their occurrence relative to the moment of release and the character of changes of spectral parameters produces signal effects (SE) which may be classified as: the unique burst, the quasiperiodic group of bursts, the regular changes of spectral parameters and wave processes. Observed types of SE are analogous to those seen when the releases were produced at the heights from 140 to 160 km. The result of experimental observations testify that there are special geophysical phenomena produced by barium releases. 相似文献
352.
A.F. Cook 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1983,3(3):83-86
Saturn lies at nearly twice Jupiter's distance from the Sun and nearly all parts of its system are characterized by much smaller scales than those which are important in the case of Jupiter. This appears in the structures of the planet's atmosphere, in the sizes of classical satellites other than Titan vis-à-vis those of the Galilean satellites, in the plethora of small Saturnian satellites, especially Lagrangian co-orbiters, in the structure of Saturn's F-Ring as contrasted with that of Jupiter's Ring and finally in the highly structured detail in Saturn's Rings, much finer than seriously considered in past theoretical discussions. Uranus' Rings were unknown until five years ago. The discovery and observation of these rings have revived contributions to theory originally intended for application to Saturn's Rings. Models have also been generated for eccentric rings for application to Uranus' Rings which also apply to those of Saturn. These two classes of model are reviewed in the present paper along with the first tentative steps made down the road to unravelling the complexity of Saturn's Rings. 相似文献
353.
J.-M. Lamarre B. Gondet R. Gispert C. Emerich F. Rocard 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(9):277-281
The imaging Channel of the IKS Instrument placed on board the Vega fly-by probes will perform measurements of the infrared emission of the central region of Comet Halley at distances in the 104 ? 105 km range. An encoding wheel analyses one spatial frequency of the infrared image during the whole fly-by. Inversion of this measurement will give low resolution brightness profiles of the nucleus and its immediate surroundings, in two wave-length bandpasses and in two directions of analysis. 相似文献
354.
F. Bonde-Petersen M. Suzuki N.J. Christensen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(12):31-33
The purpose was to combine bicycle exercise and LBNP as a model to investigate the mechanisms regulating circulation during gravitatiobal stresses. METHODS: Cardiac Output (CO) by acetylene-, argon-, oxygen rebreathing; Heart Rate (HR) from ECG; Mean Arterial Pressure (MAP) by arm cuff; Plasma Nor-Epinephrine (NE), Epinephrine (E), and Lactate (HLa) by isotope and enzymatic techniques respectively. Total Peripheral Resistance (TPR)=MAP/CO and stroke volume (SV)=CO/HR. Six subjects exercised at 180–200 Watts in the upright position on a mechanically braked computer controlled small bicycle ergometer placed in a LBNP box. The above parameters were measured at rest and at 5 and 9 min of exercise without and with LBNP at −30 or −40 mmHg (depending on LBNP tolerance). RESULTS AND CONCLUSIONS: In the face of an increased sympathetic nervous activity (Ne+E, TPR, and HR increased) during exercise in LBNP, there was a decrease in CO and SV indicating that the venous return was insufficient. However, HLa was unchanged demonstrating that the blood flow to the working muscles did not suffer. 相似文献
355.
T.E. Cravens A.F. Nagy T.I. Gombosi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(9):33-36
Model calculations of the dayside ionosphere of Venus are presented. The coupled continuity and momentum equations were solved for O2+, O+, CO2+, C+, N+, He+, and H+ density distributions, which are compared with measurements from the Pioneer Venus ion mass spectrometer. The agreement between the model results and the measurements is good for some species, such as O+, and rather poor for others, such as N+, indicating that our understanding of the dayside ion composition of Venus is incomplete. The coupled heat conduction equations for ions and electrons were solved and the calculated temperatures compared with Pioneer Venus measurements. It is shown that fluctuations in the magnetic field have a significant effect on the energy balance of the ionosphere. 相似文献
356.
G.H. Schwehm R.H. Giese F. Giovane D.W. Schuerman J.L. Weinberg 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1981,1(8):121-125
The 1985 International Solar Polar Mission will provide the first opportunity to perform measurements from out of the ecliptic and from above the solar poles. Included in this mission is the Zodiacal Light/Background Starlight Experiment of the Ruhr-University Bochum, FRG (in collaboration with the State University of New York at Albany). The experiment is based on the use of a multicolor, sky-scanning photopolarimeter, which will be carried on the NASA S/C.The scientific objectives of the experiment are to investigate the intensity, polarization, and color of the diffuse sky brightness and determine the spatial distribution and physical properties of the interplanetary dust, including a possible interstellar component, as a function of S/C position in and out of the ecliptic.The instrument will allow simultaneous measurements in two separate wavelength bands. Measurements will be performed at 180, 220, 240, 280, 320, 350, 360, 440, 540, 640, 800 nm, including the state of polarization. Two different fields-of-view (1 sq deg and 5.6 sq deg) can be selected.The use of a microprocessor system in the instrument electronics will provide flexibility in measurement sequences and programs, on-board data processing and data quality control. 相似文献
357.
Mancianti M. Russo F. Verrazzani L. 《IEEE transactions on aerospace and electronic systems》1975,(3):393-399
This paper analyzes a sequential feedback detection scheme derived by Kramer's nonsequential intermittent one; in addition to the noiseless information feedback channel, it makes use of a noiseless decision feedback channel. Expressions for the normalized average evergy per symbol, average decision time, probability of error, and average power are derived. The comparison with the nonsequential intermittent scheme shows that the proposed one allows an appreciable gain in transmission rate and requires a smaller peak-to-average power ratio. 相似文献
358.
359.
360.
Accurate solutions of minimal time Earth-Mars and Earth-Venus heliocentric trajectories are calculated with a shooting-Newton method. The flight times are less and the steering histories are diferent than those presented in [1], thus contradicting the optimality claims in [1]. 相似文献