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991.
992.
The DPLIS and the results of the solar activity cycle No. 20 forecast with the help of it are described briefly.  相似文献   
993.
Ring-like filaments have been detected on the spectroheliograms in the H-alpha line. Inside these filaments the magnetic field flux has a predominant polarity. Some of the dark filaments are connected by filament channels which can be seen at the limb either as (a) weak prominences or (b) dense low chromospheric features or (c) multi-channel system of matter flow between two prominences or (d) common quiescent prominences. The filament and the filament channel together form a continuous closed contour and outline the region of thef polarity particularly at the beginning of the solar cycle. The change in sign of the polar field of the Sun is associated with the drift of the filament band to high latitudes.  相似文献   
994.
Possible solar neutron emission associated with five SMM gamma-ray events on 7 June 1980, 21 June 1980, 6 November 1980, 26 November 1982 and 25 April 1984 was found from analysis of 10-minute records of the ground-based neutron monitor at Tokyo. Of these the two events on 21 June 1980 and 25 April 1984 have been already known as neutron events. The time histories of the neutron monitor count rate are compared with those of the gamma-ray count rate and the possibility of energetic neutron emission at the flare site is discussed.  相似文献   
995.
Stars in the Aur OB-2 and Sco OB-1 associations, located in the direction of the galactic anticenter and center, respectively, have been observed for interstellar extinction. No effects due to changes of grain composition across such large distances are seen. A star exhibiting a peculiar extinction is found in each association. The properties of the responsible dust grains are discussed in terms of a two-component dust mixture: graphite and uncoated silicates. The column density both of graphite and silicate atoms are found to be higher than in stars of the same associations exhibiting a regular UV extinction.Based on observations by the International Ultraviolet Explorer collected at the Villafranca Satellite Tracking Station of the European Space Agency.  相似文献   
996.
In the region of the formation of weak and medium-strong lines, the microturbulence increases with height (V ver=0.7–0.9 km s-1, V hor= 1.1–1.5 km s-1), the macroturbulence decreases (V ver=1.6–1.4 km s-1, V hor= 2.4–1.5 km s-1), and the total velocity field (vertical component) is depth-independent (1.7 km s-1). The empirical damping constants for Fe, Ti, Cr, Ni lines are equal 1.36, 1.76, 1.66, 1.66, respectively. The correlation length (the Kubo-Anderson process has been used) in the solar photosphere is 520–550 km.  相似文献   
997.
The main results of a study of a catalogue of physical parameters of 1041 spectroscopic binaries are presented. The distribution of spectroscopic binaries over all main parametersM 1, a, e, M1/M2, P, and certain dependencies between some of them have been found.
  1. It appears that among bright (m v?3 m –5 m ) stars withM?1M , about 40% are apparently spectroscopic binaries with comparable masses of components.
  2. The majority of spectroscopic binaries with the ratio of the large semiaxis of the orbit to the radius of the primarya/R 1?20, have eccentricities close to zero. This is probably a consequence of the tidal circularization of orbits of close binaries by viscous friction.
  3. The discovery of duplicity of double-line spectroscopic binaries is possible only if the semiamplitude of radial velocityK 1 is almost 10 times higher than the semiamplitude of the radial velocity of a single-line spectroscopic binary of the same mass.
  4. Double-line spectroscopic binaries witha/R ?6(M 1/M )1/3,M 1M 2?1.5M are almost almost absent, and the number of stars witha/R ?6(M 1/M )1/3,M 1≈1.5M is relatively low.
  5. The distribution of unevolved SB stars over the large semiaxis may be described by the expression d(N d/Nt)≈0.2 d loga for 6(M 1/M )1/3?a/R ?100.
  6. The intial mass-function for primaries of spectroscopic binaries is the same Salpeter function dN d≈M 1 ?2.35 dM 1 for 1?M 1/M ?30.
  7. It is possible to explain the observed ratio of the number of single-line spectroscopic binaries to the number of double-line binaries if one assumes that the average initial mass ratio is close to 1 and that the mass of the postmass-exchange remnant of the primary exceeds the theoretical one and/or that half of the angular momentum of the system is lost during mass-exchange.
  8. The above-mentioned distributions ofM 1 anda and assumptions on the mass of remnant and/or momentum loss also allow us to explain the observed shapes of dN/dM, dN/dq, and dN/da distributions after some selection effects are taken into account.
  相似文献   
998.
Lithofacies of the productive Upper Triassic-Lower Jurassic deposits of the Eastern Caspian region, studied in wells on the Caspian coast and exposed in the outcrops of the Mountainous Mangyshlak, are described and analyzed. The similarity of the structure of the Mesozoic sedimentary beds of the Middle Caspian Basin and of those of the land adjacent to its eastern coast is confirmed. Comparative analysis of lithofacies allowed the reconstruction of the paleogeographic setting and depositional environments in the studied region during the Early Jurassic. A unique fossil plant occurrence is discovered in the upper part of the Lower Jurassic series (in the lower subformation of the Kokala Formation; Eastern Caspian region). Fossil plant taphonomy and the lithology of host rocks in the occurrence resulted from unusual paleogeographic settings that existed in the Middle Caspian Basin at the time of the Early-Middle Jurassic boundary.  相似文献   
999.
Data obtained by the Explorer 34 satellite regarding the degree of anisotropy of ≳ 70 keV electrons of solar origin are reported. It is shown that the anisotropies are initially field aligned, and that they decay to ≲ 10% in a time of the order of 1 hr. The decays of the concurrent ionic and electronic anisotropies for one well observed event are in good agreement with the diffusive propagation model of Fisk and Axford. The data suggest parallel diffusion coefficients for both ions and electrons that are rigidity independent. From considerations of a long lived electron event, it is shown that the electronic fluxes exhibit ‘equilibrium’ anositropies at late times. These are interpreted as indicating that convective removal at the solar wind velocity is the dominant mechanism whereby solar cosmic ray electrons (∼- 70 keV) leave the solar system. They also indicate that there is a positive density gradient at late times in a solar electron event. The data suggest that this was established prior to the establishment of a similar gradient for the cosmic ray ions. This research was supported by the National Aeronautics and Space Administration under contracts NASr-198 and NAS5-9075. The research in India was supported by funds from the Department of Atomic Energy, Government of India and funds from the grant NAS-1492 from the National Academy of Sciences, U.S.A. Support in data analysis was also provided by Air Force Cambridge Research Laboratories, and by the Australian Research Grants Committee.  相似文献   
1000.
Satellite and other observations have shown that H+ densities in the mid-latitude topside ionosphere are greatly reduced during magnetic storms when the plasmapause and magnetic field convection move to relatively low L-values. In the recovery phase of the magnetic storm the convection region moves to higher L-values and replenishment of H+ in the empty magnetospheric field tubes begins. The upwards flow of H+, which arises from O+—H charge exchange, is initially supersonic. However, as the field tubes fill with plasma, a shock front moves downwards towards the ionosphere, eventually converting the upwards flow to subsonic speeds. The duration of this supersonic recovery depends strongly on the volume of the field tube; for example calculations indicate that for L = 5 the time is approximately 22 hours. The subsonic flow continues until diffusive equilibrium is reached or a new magnetic storm begins. Calculations of the density and flux profiles expected during the subsonic phase of the recovery show that diffusive equilibrium is still not reached after an elapsed time of 10 days and correspondingly there is still a net loss of plasma from the ionosphere to the magnetosphere at that time. This slow recovery of the H+ density and flux patterns, following magnetic storms, indicates that the mid-latitude topside ionosphere may be in a continual dynamic state if the storms occur sufficiently often.  相似文献   
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