全文获取类型
收费全文 | 131篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 4篇 |
地球物理 | 15篇 |
地质学 | 63篇 |
海洋学 | 6篇 |
天文学 | 39篇 |
自然地理 | 3篇 |
出版年
2022年 | 6篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 7篇 |
2006年 | 10篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 6篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有132条查询结果,搜索用时 15 毫秒
21.
Broad iron Κα emission with a characteristic two-peaked profile is observed in most Seyfert galaxies in the X-ray. We have calculated the profiles of such lines emitted by an accretion disk in a Schwartzschild metric. The dependence of the temperature distribution in the disk on the line shape is demonstrated. All the calculations include general relativistic effects. The disk material is assumed to move in circular geodesics in the equatorial plane. The line profile is extremely complex, even in a traditional model for the radial temperature distribution, complicating interpretation of the observational data. 相似文献
22.
Belyaev Yu. R. Panin A. V. Kiryuhina A. D. Koshurnikov A. V. Kramynin A. M. Pavlov M. A. Konstantinov E. A. Kurbanov R. N. Zakharov A. L. Sychev N. V. 《Doklady Earth Sciences》2022,506(1):S84-S93
Doklady Earth Sciences - A complex of works including geomorphological deciphering, field survey, drilling, electric prospecting, and dating of deposits using the radiocarbon method and optically... 相似文献
23.
A standard pair of equations is used to describe the behaviour of a single monoenergetic particle (proton or electron) population on a geomagnetic flux tube drifting in the magnetosphere. When particle losses from the drifting flux tube into the ionosphere are neglected, this behaviour is adiabatic in a thermodynamic sense. For a population of particles with an isotropic pitch-angle distribution, the generalization of that system of equations is obtained by adding radial and azimuthal spatial diffusion terms. The magnetic field is taken to be dipolar in the inner magnetosphere. The potential electric field is assumed to consist of magnetospheric convection and corotation components. Experimental data are used to estimate the radial equatorial profiles of the plasma sheet pressure. Assuming that the local time and L-shell variations are separable and supposing steady-state conditions, the expressions for the diffusion tensor components are evaluated. The influence of spatial diffusion on the radial and azimuthal profiles of the plasma pressure in the inner plasma sheet is also discussed. 相似文献
24.
Using statistically significant data, we show that the GPS observation method is efficient for revealing the response of the upper atmosphere to global synoptic processes with the help of correlation techniques. 相似文献
25.
V. S. Zakharov 《Moscow University Geology Bulletin》2013,68(3):165-174
The noise component in the time series of Earth surface displacements that were obtained with the Global Positioning System (GPS) is analyzed for 19 points. The methods of dynamic system and fractal set theory are applied. The analyzed parameters include the correlation dimension, spectral scaling parameter, fractal dimension, and the Hurst exponent. We detect that GPS time series demonstrate fractal properties in a range of over one order of magnitude of frequency (flicker noise). The fractal characteristics of the studied series and seismotectonic features of the studied regions are characterized by a relationship that can be explained by the dynamic characteristics of the block models and seismicity. 相似文献
26.
The upper Volgian Substage in Northeast Siberia (Nordvik Peninsula) and its Panboreal correlation based on ammonites 总被引:1,自引:0,他引:1
Section of the middle and upper Volgian substages and basal Boreal Berriasian in the Cape Urdyuk-Khaya (Nordvik Peninsula) is largely composed of dark argillites substantially enriched in Corg. Characteristic of the section is a continuous succession of ammonite, foraminiferal, ostracode, and dinocyst zones known also in the other Arctic areas. Boundaries of the upper Volgian Substage are recognizable only based on biostratigraphic criteria. The succession of the middle Volgian Taimyrosphinctes excentricus to basal Ryazanian Hectoroceras kochi zones is characterized. The range of the substage is revised. The lower Exoticus Zone, where ammonites characteristic of the Nikitini Zone upper part in the East European platform have been found, is referred to the middle Volgian Substage. Newly found ammonites are figured. Two possible positions of the Jurassic-Cretaceous boundary in the Arctic region, i.e., at the lower and upper boundaries of the Chetae Zone at the top of the upper Volgian Substage, are discussed. 相似文献
27.
A.F. Zakharov 《Astrophysics and Space Science》1997,252(1-2):213-224
We consider gravitational radiation in the nonspherical symmetrical evolution of supernovae. Unlike the gravitational radiation analysis of Imshennik & Popov performed using the formalism of Peters & Mathews, our analysis uses the (PN)5/2 approximation by Damour & Deruelle and Lincoln & Will. We show that the eccentricity is larger than 0.1 at the time when the Roche lobe is filled by the low-mass component, demonstrating that the conclusion of Imshennik and Popov that the final eccentricity is less than 0.1 is incorrect. If the supernova lies in the Large Magellanic Cloud (R = 50 kpc), we estimate the amplitude of gravitational waves to be h 8 × 10-20. The frequency of the emitted gravitational waves is about 1 kHz. 相似文献
28.
A. B. Kuzmichev V. A. Zakharov M. K. Danukalova 《Stratigraphy and Geological Correlation》2009,17(4):396-414
The section of Mesozoic terrigenous deposits over 1200 m thick has been described, and a new geological map of the Stolbovoi Island southern half has been compiled. The inference has been made that the sedimentary sequence represents a single uniform turbidite complex, which is indivisible into lithological units and which does not show transition to shallow-marine facies either in the visible foot section or visible roof section. The complex accumulated in the foreland basin emerged on the margin of the Novosibirsk-Chukchi continental block during the Anyuian orogeny. The presence of upper Volgian deposits (Upper Jurassic) with a visible thickness of 640 m, Berriasian (Ryazanian) deposits about 100-m thick, and lower Valanginian deposits with a visible thickness of ~200 m has been established on the basis of identification of fossils represented by remains of bivalve mollusks (the genus Buchia). Finds of upper Volgian buchias in the southeastern part of the island are inconsistent with field geological observations of the sequence of deposits. Paleontological data acquired for the island southern part suggest the presence of a transverse thrust fault, along which upper Volgian rocks were thrust over lower Neocomian rocks. The possibility of another interpretation of the data has also been considered. The correlation of the Buchia Beds of the Stolbovoi Island, Nordvik Peninsula, the basin of the Anyui River, and northern California has been carried out. The inference about a close relationship between the biota of the Stolbovoi Island and the North Pacific paleobiogeographic realm has been drawn. 相似文献
29.
A. E. Shlezinger Yu. B. Gladenkov V. A. Zakharov 《Stratigraphy and Geological Correlation》2006,14(6):690-692
Despite great practical achievements, sequence stratigraphy failed to elaborate until now the reliable technique for establishing relative sea-level fluctuations (RSLF). The method proposed recently by Yu.A. Volozh with colleagues for determining the RSLF represents one of interesting but unconvincing attempts in this respect. Use of their method for fundamental and practical purposes requires prudence because of potential errors. 相似文献
30.
A method for determining the celestial coordinates of the center of the disk of the Earth from satellite observations with an accuracy of 1–5 arcseconds is suggested. The choice of the most suitable wavelength range is substantiated. 相似文献