全文获取类型
收费全文 | 1195篇 |
免费 | 74篇 |
国内免费 | 6篇 |
专业分类
测绘学 | 23篇 |
大气科学 | 86篇 |
地球物理 | 321篇 |
地质学 | 568篇 |
海洋学 | 91篇 |
天文学 | 136篇 |
综合类 | 5篇 |
自然地理 | 45篇 |
出版年
2024年 | 4篇 |
2023年 | 6篇 |
2022年 | 19篇 |
2021年 | 27篇 |
2020年 | 23篇 |
2019年 | 25篇 |
2018年 | 58篇 |
2017年 | 60篇 |
2016年 | 63篇 |
2015年 | 55篇 |
2014年 | 75篇 |
2013年 | 114篇 |
2012年 | 44篇 |
2011年 | 85篇 |
2010年 | 73篇 |
2009年 | 79篇 |
2008年 | 54篇 |
2007年 | 49篇 |
2006年 | 36篇 |
2005年 | 23篇 |
2004年 | 34篇 |
2003年 | 25篇 |
2002年 | 25篇 |
2001年 | 20篇 |
2000年 | 17篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 19篇 |
1993年 | 8篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 3篇 |
1989年 | 10篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1977年 | 4篇 |
1975年 | 7篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1962年 | 2篇 |
排序方式: 共有1275条查询结果,搜索用时 0 毫秒
411.
Gilles Coppier Philippe Griveaud François-Dominique de Larouziere Christian Montenat Philippe Ott d’Estevou 《Geodinamica Acta》2013,26(1):37-51
AbstractNeogene deformations have deeply disturbed the initial architecture of the pile of nappes within the Eastern Betic zone. The Arc of Aguilas, displaying a southeast-facing concavity, is a spectacular example of such a post-nappe structuration. Miocene deposits involved in the torsion of the Arc provide a chronology of the deformation. The Arc of Aguilas is one element within a system of rigid-plastic indentation including the following units, from the inner (SE) to the outer (NW) zones : — A rigid block, little deformed, located in the present day abyssal plain, play the part of the indenter. — A structural pad corresponding to the Aguilas Arc itself. It was severely folded during Miocene times. — A large peripheral zone mainly subjected to faulting during the Neogene (essentially strike-slip faults). These faults control the evolution of different types of sedimentary basins during the Late Neogene (Tortonian to Pliocene). Two large shear zones: N020 sinistral (Palomares and Terreros faults), N100 dextral (Las Moreras faults) guided the deformation of the Aguilas Arc within a compressive stressfield of which major tensor axis oscillated between NW-SE and N-S. 相似文献
412.
413.
AbstractThe Vestfirdir Peninsula of northwestern Iceland mainly consists of tholeiitic lava flows, 8–14 Ma old, gently dipping to the southeast. A detailed study of strike-slip and normal faulting allowed identification of two main paleostress regimes. Two sets of normal faults were recognized. The largest set trends ENE-WSW to NNE-SSW; the minor set trends NW-SE to WNW-ESE. Concerning the major extension, the reconstruction of paleostress trajectories shows a gradual change in trend from ESE-WNW, in the northern half of the peninsula, to NNW-SSE to the south. The minor extension also shows a gradual change from NNE-SSW to ENE-WSW trends, from north to south. The nearly constant perpendicularity between the major and minor trends of extension is accounted for by permutation of stress axes within the general pattern of extension related to oceanic rifting. The progressive azimuthal change of the major extension trend, from northeast to southwest across the peninsula, is interpreted as the expression of a change in trend of the extinct Skagi-Snaefells rift, a structure that cannot be reconstructed directly through geological mapping. The average trends of extension in the southern Vestfirdir Peninsula, N150°E, suggest a N60°E trend for the ancient Snaefells rift segment. Likewise, the N100–110°E trends of extension in northern Vestfirdir suggest a N10–20°E trend for the Skagi paleo-rift., © Elsevier, Paris 相似文献
414.
AbstractThroughout SE France, 13C-values of CO2releases suggest that a variable part of the C02 emission derives from mantle and/or lower crust. Carbon dioxide emission takes place in various geological settings. Geodynamical analyses lead to the identification of five provinces: the Sub-Alpine Ranges, the French Massif Central, the Mediterranean part of the Languedoc, the western Pyrénées and the Alps at the West of the Penninic front. Possible correlations are suggested between CO2 flux and tectonic history of the structural provinces.Possible processes by which CO2 is extracted from the mantle, stored and transferred to the surface are investigated for each of these provinces. Major crustal scale gas movements may have taken place during the Carboniferous (Variscan and Late Variscan tectogenesis), the Lias and Dogger (rifting), the Upper Cretaceous and the Cenozoic (Alpine tectogenesis), A model of successive circulations of fluids on the scale of the whole Southeastern France CO2-belt is proposed. This integrated isotopic and geodynamic approach contributes to a better understanding of the regional CO2flux. 相似文献
415.
We explore the possible relationships between a structural heterogeneity, the hydrothermal system, and the intrusive activity
at Piton de la Fournaise volcano. Geological and geophysical data show that as the result of repeated collapses (the last
one in 2007), a cylinder of faulted, fractured, and crumbled rocks must exist between the surface and the top of a magma reservoir
at about sea level. This structure constitutes a major geological heterogeneity. An obvious spatial correlation exists between
this column of fractured and brecciated rock and the location of (1) most of the seismic activity, (2) a low-resistivity dome,
(3) a huge self-potential anomaly, (4) thermal evidence of hydrothermal activity, and (5) the root of magma intrusions. The
dominant factors that make this structural heterogeneity a trap for the activity are probably its higher permeability and
its weaker mechanical strength. Evidence exists for the presence of an active hydrothermal system confined in this permeable
zone. The long-term stability of the activated zone above sea level and the similarity of the pre-eruptive crises, in spite
of the inferred large perturbation of the magmatic system in 1998, suggest a common triggering mechanism for all the eruptions
since at least the first data recorded by the observatory in 1980. This mechanism can be purely magmatic, resulting from the
pressurization of a reservoir, but we also propose that the hydrothermal system may play a role in the development of volcanic
instabilities. A qualitative model is proposed to explain the triggering of magma intrusions by hydrothermal processes, and
its speculative aspects are discussed. This work represents a first attempt to integrate the structural and dynamic information
in a unified framework at Piton de la Fournaise. 相似文献
416.
417.
Franck Lavigne Raphaël Paris Delphine Grancher Patrick Wassmer Daniel Brunstein Franck Vautier Frédéric Leone François Flohic Benjamin De Coster Taufik Gunawan Christopher Gomez Anggri Setiawan Rino Cahyadi Fachrizal 《Pure and Applied Geophysics》2009,166(1-2):259-281
This paper presents the results from an extensive field data collection effort following the December 26, 2004 earthquake and tsunami in Banda Aceh, Sumatra. The data were collected under the auspices of TSUNARISQUE, a joint French-Indonesian program dedicated to tsunami research and hazard mitigation, which has been active since before the 2004 event. In total, data from three months of field investigations are presented, which detail important aspects of the tsunami inundation dynamics in Banda Aceh. These include measurements of runup, tsunami wave heights, flow depths, flow directions, event chronology and building damage patterns. The result is a series of detailed inundation maps of the northern and western coasts of Sumatra including Banda Aceh and Lhok Nga. Among the more important findings, we obtained consistent accounts that approximately ten separate waves affected the region after the earthquake; this indicates a high-frequency component of the tsunami wave energy in the extreme near-field. The largest tsunami wave heights were on the order of 35 m with a maximum runup height of 51 m. This value is the highest runup value measured in human history for a seismically generated tsunami. In addition, our field investigations show a significant discontinuity in the tsunami wave heights and flow depths along a line approximately 3 km inland, which the authors interpret to be the location of the collapse of the main tsunami bore caused by sudden energy dissipation. The propagating bore looked like a breaking wave from the landward side although it has distinct characteristics. Patterns of building damage are related to the location of the propagating bore with overall less damage to buildings beyond the line where the bore collapsed. This data set was built to be of use to the tsunami community for the purposes of calibrating and improving existing tsunami inundation models, especially in the analysis of extreme near-field events. 相似文献
418.
Sandra Barbouteau Patrick Rasolofosaon Noalwenn Dubos‐Sallée Virginie Vassil Valérie Poitrineau Jean‐François Nauroy 《Geophysical Prospecting》2016,64(5):1368-1385
This article introduces an alternative experimental procedure for measuring the elastic properties of a solid material at laboratory scale, using both the principles of passive seismic interferometry and resonance ultrasound spectroscopy. We generate noise into the studied sample with a pneumatic air blow gun, and we cross‐correlate the signals recorded with two passive piezoelectric sensors put in soft contact with the sample surface. Resonance phenomena are induced in the sample, but in contrast with conventional resonance ultrasound spectroscopy experiments, we have no control over the injected frequencies that are sent all together within the noise spectrum. The spectrum of the correlogram is a good approximation of the resonance spectrum of the vibrating sample and can be inverted in terms of the elastic moduli of the constituent material of the sample. The experimental procedure is validated on samples made of standard materials (here, aluminium and Plexiglas) by consistently comparing the inverted elastic velocities with the velocities independently measured with the conventional technique of ultrasonic pulse transmission. Moreover, we got similar positive results on dry rock samples, such as Vilhonneur limestone. These encouraging preliminary results open up promising prospects for monitoring fluid substitution in rock samples using the technique described in this paper. 相似文献
419.
Denudation intensity and control in the Chinese Tian Shan: new constraints from mass balance on catchment‐alluvial fan systems 下载免费PDF全文
Laure Guerit Laurie Barrier Marc Jolivet Bihong Fu François Métivier 《地球表面变化过程与地形》2016,41(8):1088-1106
Tectonics and climate are usually seen as the main controlling factors of denudation rates, which seem to rise with the tectonic activity and to decrease when the climate becomes drier. However, the low denudation rates observed in semi‐arid to arid contexts are generally measured on orogenic plateaus where the respective influence of the flat relief and the dry climate cannot really be unravelled. The Chinese Tian Shan was chosen as a case study. In the northern piedmont of this mountain range, a series of well‐preserved Quaternary alluvial fans offer the opportunity to perform a mass balance study at the scale of several catchment areas and several hundreds of thousands of years. Based on a geometrical reconstruction of these fans, the volumes of sediments exported out of 10 drainage basins during the Middle–Late Pleistocene (from ~300 to ~12 kyr) and the Holocene (from ~12 kyr to present) have been estimated. From these volumes, an average denudation rate of ~135 m/Myr was determined in the Tian Shan Range for the last 300 kyr. In agreement with other mass balances performed in the same area, the typical denudation intensity of the northern Tian Shan is thus of a few hundred meters per million years at most, regardless of the space and time scales considered. From a comparison with denudation rates in other mountain ranges throughout the world, we suggest that a dry climate can dramatically limit the denudation intensity even in active orogenic systems with a high topographic gradient like the Tian Shan. As a result, the time required to reach equilibrium between denudation and rock uplift in these systems could be extremely long (i.e. of more than several million years). Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
420.
Marc Peipoch Esperança Gacia Alba Blesa Miquel Ribot Joan L. Riera Eugènia Martí 《Aquatic Sciences - Research Across Boundaries》2014,76(2):203-215
We examined the relevance of dissolved inorganic nitrogen (DIN) forms (nitrate and ammonium) in stream water as N sources for different macrophyte species. To do this, we investigated the variability and relationships between 15N natural abundance of DIN forms and of four different macrophyte species in five different streams influenced by inputs from wastewater treatment plants and over time within one of these streams. Results showed that 15N signatures were similar in species of submersed and amphibious macrophytes and in stream water DIN, whereas 15N signatures of the riparian species were not. 15N signatures of macrophytes were generally closer to 15N signatures of nitrate, regardless of the species considered. Our results showed significant relationships between 15N signatures of DIN and those of submersed Callitriche stagnalis and amphibious Veronica beccabunga and Apium nodiflorum, suggesting stream water DIN as a relevant N source for these two functional groups. Moreover, results from a mixing model suggested that stream water DIN taken up by the submersed and amphibious species was mostly in the form of nitrate. Together, these results suggest different contribution to in-stream N uptake among the spatially-segregated species of macrophytes. While submersed and amphibious species can contribute to in-stream N uptake by assimilation of DIN, macrophyte species located at stream channel edges do not seem to rely on stream water DIN as an N source. Ultimately, these results add a functional dimension to the current use of macrophytes for the restoration of stream channel morphology, indicating that they can also contribute to reduce excess DIN in streams. 相似文献