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Byurakan Astrophysical Observatory, Armenian Academy of Sciences; Astronomical Institute, Uzbek Academy of Sciences. Translated from Astrofizika, Vol. 32, No. 1, pp. 39–47, January–February, 1990.  相似文献   
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We present our broadband UBVRI observations of the nucleus of the Seyfert galaxy NGC 4151 from 1989 until 2000 at three astronomical observatories: the Crimean Station of the Sternberg Astronomical Institute, the Special Astrophysical Observatory in the Caucasus, and the Maidanak Observatory of the Ulugbek Astronomical Institute in Uzbekistan. All data have been reduced to a single system and are given for an A=27.″5 aperture. Regular R and I observations show that the pattern of optical variability is the same in all bands; the relative variability amplitude decreases from U to V, but it is even slightly larger in R than in V. The variability amplitude of the component fluctuating on time scales of several months is proportional to the UBV flux from the component varying on times scales of several years. The correlation between the slow and rapid components significantly weakens in the red, and no correlation has been found between the flux from the slow component and the amplitude of the rapid component in R. The color characteristics correspond to the recombination radiation from an optically thick plasma beyond the Balmer limit.  相似文献   
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The author outlines, in diagrammatic form, a procedure for the joint use of old maps (topographic, land survey, etc.) and current space imagery to compile maps of environmental change. The ancient maps reveal land use and physical conditions which serve as a benchmark for evaluation of subsequent change. Space imagery is useful both in updating the current state of the environment and providing a cartographic base for the preparation of final maps. Selected areas of Moscow Oblast are used as test sites. Translated from: Izvestiya vuzov, Geodeziya i aerofotos' yem-ka, 1985, No. 1, pp. 104-109.  相似文献   
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We present the results of photometric observations of Saturn's seventh satellite Hyperion and four other planetary satellites: Saturn's moon Phoebe and three Jovian satellites Himalia, Elara, and Pasiphae. The observations have been conducted from September, 1999 to March, 2000, and during September–October, 2000. Analysis of periodic variations in Hyperion's lightcurve was performed. The lightcurve was modeled using the software package developed for calculating the rotational dynamics of a satellite. Our data generally indicate that over the period of observations Hyperion was in the chaotic mode of rotation.  相似文献   
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In some solar energetic particle events relatively intense proton fluxes are accompanied by disproportionately weak intensity of-burst. A possible reason for such a situation is discussed in this paper. We use the idea that the dynamics of particles in flare loops strongly influences the efficiency of their escape into interplanetary space. It is proposed that in events with weak impulsive phase flare loops are large sized and stretched high into the corona, the magnetic field is weak, and the level of excited turbulence is rather low. All this leads to the weak diffusion of protons into the loss cone, a large lifetime of a particle in the loop ( 103 s) and, hence, to the relatively high efficiency of their escape into interplanetary space.  相似文献   
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Fine-grained clay subfractions (SFs) with a particle size of <0.1, 0.1–0.2, 0.2–0.3, 0.3–0.6, 0.6–2.0, and 2–5 m separated from the claystone of Upper Precambrian Pumanskaya and Poropelonskaya formations on the Srednii Peninsula were studied by transmission electron microscopy, X-ray diffraction, and Rb–Sr methods. All subfractions consist of the low-temperature illite and chlorite, and the contribution of chlorite decreases with diminishing particle size. The crystallinity index and I 002/I 001 ratio increase from coarse- to fine-grained SFs. The leaching by ammonium acetate solution and the Rb–Sr systematics in combination with mineralogical and morphological data indicate that illite in Upper Proterozoic claystone from the Srednii Peninsula was formed during three time intervals: 810–830, 610–620, and about 570 Ma ago. The first generation of this mineral with a low Rb/Sr ratio dominates in coarse-grained SFs while the second and third generations with a high Rb/Sr ratio prevail in fine-grained SFs. All of the three generations are known in the Poropelon claystone, whereas the Puman claystone contains only illite of the first and second generations. Geological processes responsible for the multistage illite evolution in claystones are discussed.  相似文献   
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