全文获取类型
收费全文 | 526篇 |
免费 | 9篇 |
国内免费 | 13篇 |
专业分类
测绘学 | 6篇 |
大气科学 | 47篇 |
地球物理 | 110篇 |
地质学 | 248篇 |
海洋学 | 16篇 |
天文学 | 99篇 |
综合类 | 4篇 |
自然地理 | 18篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 15篇 |
2020年 | 13篇 |
2019年 | 23篇 |
2018年 | 34篇 |
2017年 | 29篇 |
2016年 | 32篇 |
2015年 | 19篇 |
2014年 | 27篇 |
2013年 | 46篇 |
2012年 | 25篇 |
2011年 | 20篇 |
2010年 | 21篇 |
2009年 | 29篇 |
2008年 | 17篇 |
2007年 | 21篇 |
2006年 | 30篇 |
2005年 | 16篇 |
2004年 | 16篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 6篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1968年 | 1篇 |
1967年 | 3篇 |
1966年 | 2篇 |
排序方式: 共有548条查询结果,搜索用时 15 毫秒
11.
Doklady Earth Sciences - The experimental data on diamond growth in the Fe–Ni–S–C and Fe–S–C systems with a sulfur content of 5–14 wt % at 5.5 GPa and... 相似文献
12.
13.
The impact of the gustiness on surface waves under storm conditions is investigated with focus on the appearance of wave groups with extreme high amplitude and wavelength in the North Sea. During many storms characterized by extremely high individual waves measured near the German coast, especially in cold air outbreaks, the moving atmospheric open cells are observed by optical and radar satellites. According to measurements, the footprint of the cell produces a local increase in the wind field at sea surface, moving as a consistent system with a propagation speed near to swell wave-traveling speed. The optical and microwave satellite data are used to connect mesoscale atmospheric turbulences and the extreme waves measured. The parameters of open cells observed are used for numerical spectral wave modeling. The North Sea with horizontal resolution of 2.5?km and with focus on the German Bight was simulated. The wind field “storm in storm,” including moving organized mesoscale eddies with increased wind speed, was generated. To take into account the rapid moving gust structure, the input wind field was updated each 5?min. The test cases idealized with one, two, and four open individual cells and, respectively, with groups of open cells, with and without preexisting sea state, as well the real storm conditions, are simulated. The model results confirm that an individual-moving open cell can cause the local significant wave height increase in order of meters within the cell area and especially in a narrow area of 1–2?km at the footprint center of a cell (the cell's diameter is 40–90?km). In a case of a traveling individual open cell with 15?m·s?1 over a sea surface with a preexisting wind sea of and swell, a local significant wave height increase of 3.5?m is produced. A group of cells for a real storm condition produces a local increase of significant wave height of more than 6?m during a short time window of 10–20?min (cell passing). The sea surface simulation from modeled wave spectra points out the appearance of wave groups including extreme individual waves with a period of about 25?s and a wavelength of more than 350?m under the cell's footprint. This corresponds well with measurement of a rogue wave group with length of about 400?m and a period of near 25?s. This has been registered at FiNO-1 research platform in the North Sea during Britta storm on November 1, 2006 at 04:00 UTC. The results can explain the appearance of rogue waves in the German Bight and can be used for ship safety and coastal protection. Presently, the considered mesoscale gustiness cannot be incorporated in present operational wave forecasting systems, since it needs an update of the wind field at spatial and temporal scales, which is still not available for such applications. However, the scenario simulations for cell structures with appropriate travel speed, observed by optical and radar satellites, can be done and applied for warning messages. 相似文献
14.
Andrey Pleskachevsky Susanne Lehner Thomas Heege Claudius Mott 《Ocean Dynamics》2011,61(12):2099-2120
A method to obtain underwater topography for coastal areas using state-of-the-art remote sensing data and techniques worldwide
is presented. The data from the new Synthetic Aperture Radar (SAR) satellite TerraSAR-X with high resolution up to 1 m are
used to render the ocean waves. As bathymetry is reflected by long swell wave refraction governed by underwater structures
in shallow areas, it can be derived using the dispersion relation from observed swell properties. To complete the bathymetric
maps, optical satellite data of the QuickBird satellite are fused to map extreme shallow waters, e.g., in near-coast areas.
The algorithms for bathymetry estimation from optical and SAR data are combined and integrated in order to cover different
depth domains. Both techniques make use of different physical phenomena and mathematical treatment. The optical methods based
on sunlight reflection analysis provide depths in shallow water up to 20 m in preferably calm weather conditions. The depth
estimation from SAR is based on the observation of long waves and covers the areas between about 70- and 10-m water depths
depending on sea state and acquisition quality. The depths in the range of 20 m up to 10 m represent the domain where the
synergy of data from both sources arises. Thus, the results derived from SAR and optical sensors complement each other. In
this study, a bathymetry map near Rottnest Island, Australia, is derived. QuickBird satellite optical data and radar data
from TerraSAR-X have been used. The depths estimated are aligned on two different grids. The first one is a uniform rectangular
mesh with a horizontal resolution of 150 m, which corresponds to an average swell wavelength observed in the 10 × 10-km SAR
image acquired. The second mesh has a resolution of 150 m for depths up to 20 m (deeper domain covered by SAR-based technique)
and 2.4 m resolution for the shallow domain imaged by an optical sensor. This new technique provides a platform for mapping
of coastal bathymetry over a broad area on a scale that is relevant to marine planners, managers, and offshore industry. 相似文献
15.
Andrei M. Sobolev Edmund C. Sutton Dinah M. Cragg Peter D. Godfrey 《Astrophysics and Space Science》2005,295(1-2):189-196
In studies of the environment of massive young stellar objects, recent progress in both observations and theory allows a unified treatment of data for maser and quasi-thermal lines. Interferometric maser images provide information on the distribution and kinematics of masing gas on small spatial scales. Observations of multiple masing transitions provide constraints on the physical parameters.Interferometric data on quasi-thermal molecular lines permits an investigation of the overall distribution and kinematics of the molecular gas in the vicinity of young stellar objects, including those which are deeply embedded. Using multiple transitions of different molecules, one can obtain good constraints on the physical and chemical parameters. Combining these data enables the construction of unified models, which take into account spatial scales differing by orders of magnitude.Here, we present such a combined analysis of the environment around the ultracompact HII region in W3(OH). This includes the structure of the methanol masing region, physical structure of the near vicinity of W3(OH), detection of new masers in the large-scale shock front and embedded sources in the vicinity of the TW young stellar object. 相似文献
16.
17.
18.
19.
Victor G. Kornilov Vladimir M. Lipunov Evgeny S. Gorbovskoy Aleksander A. Belinski Dmitry A. Kuvshinov Natalia V. Tyurina Nikolai I. Shatsky Anatoly V. Sankovich Aleksander V. Krylov Pavel V. Balanutsa Vadim V. Chazov Artem S. Kuznetsov Dmitry S. Zimnuhov Victor A. Senik Andrey G. Tlatov Aleksander V. Parkhomenko Denis V. Dormidontov Vadim V. Krushinsky Ivan S. Zalozhnyh Aleksander A. Popov Sergey A. Yazev Nikolai M. Budnev Kirill I. Ivanov Evgeny N. Konstantinov Oleg A. Gress Oleg V. Chvalaev Vladimir V. Yurkov Yury P. Sergienko Irina P. Kudelina 《Experimental Astronomy》2012,33(1):173-196
Presented paper describes the basic principles and features of the implementation of a robotic network of optical telescopes MASTER, designed to study the prompt (simultaneous with gamma radiation) optical emission of gamma-ray bursts and to perform the sky survey to detect unknown objects and transient phenomena. With joint efforts of Sternberg astronomical institute, High altitude astronomical station of the Pulkovo observatory, Ural state university, Irkutsk state university, Blagoveshchensk pedagogical university, the robotic telescopes MASTER?II near Kislovodsk, Yekaterinburg, Irkutsk and Blagoveshchensk were installed and tested. The network spread over the longitudes is greater than 6?h. A further expansion of the network is considered. 相似文献
20.
Aleksandr?S.?StepanovEmail author Ian?Campbell Robert?P.?Rapp Jessica?Lowczak Andrey?V.?Korsakov 《Contributions to Mineralogy and Petrology》2017,172(4):19
Wang et al. (Contrib Mineral Petrol 171:62, 2016a) present data on composition of xenolith from Southern Tibet and conclude that ulrapotassic melts from the region formed by melting mantle, and complex interaction with a crustal component. In this discussion we demonstrate that numerous observations presented by Wang et al. (2016a) can be explained by partial melting of crust followed by interaction between that melt and the mantle. We show that this model can explain the variability of magmas in such suits without evoking occurrence of coincidental, unrelated events. Moreover we demonstrate that our model of a crustal origin of the proto-shoshonite melts is now supported by independent lines of evidence such as geochemistry of restites after high- and ultrahigh- pressure melting and melt inclusion studies. 相似文献