全文获取类型
收费全文 | 333篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 5篇 |
大气科学 | 34篇 |
地球物理 | 84篇 |
地质学 | 118篇 |
海洋学 | 35篇 |
天文学 | 50篇 |
综合类 | 1篇 |
自然地理 | 17篇 |
出版年
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 22篇 |
2012年 | 14篇 |
2011年 | 30篇 |
2010年 | 15篇 |
2009年 | 26篇 |
2008年 | 28篇 |
2007年 | 16篇 |
2006年 | 34篇 |
2005年 | 16篇 |
2004年 | 18篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有344条查询结果,搜索用时 62 毫秒
101.
三峡库区三斗坪大坝区及其周围地区在1994到1998年期间,由于大坝的施工地面发生了巨大变化。这些变化在1990、1997和1998年获取的SPOT遥感图像上都有明显的记录,其中一些地面变化细节在分辨率10m的全波段(P)图像更为清楚。这里利用三种方法(高通滤波算法(HPF algorithm,Chavezet al.1991)、RWM—ARSIS方法(Ranchin and Wald,1999)和P+XS算法(Anonymous 1986))对三峡工程三斗坪大坝区的多时相高空间分辨率的SPOT图像(获取时闻为1990,1997和1998年,包括全波段P图像和多波段XS图像)进行融合处理,在提取测区地面动态变化信息的同时,从理论和实际应用的角度探讨了不同数据融合方法的效果。 相似文献
102.
Adam M. Booth John Dehls Trond Eiken Luzia Fischer Reginald L. Hermanns Thierry Oppikofer 《Landslides》2015,12(4):745-756
103.
Jauniaux T Farnir F Fontaine M Kiszka J Sarlet M Coignoul F 《Marine pollution bulletin》2011,62(6):1317-1319
The study describes cytochrome P450 1A1 (CYPA1) expression in the skin of different cetacean species (Megaptera novaeangliae, n = 15; Stenella attenuata, n = 7 and Stenella longirostris, n = 24) from the Mozambique Channel island of Mayotte. Immunohistochemical examination was performed with a monoclonal antibody against scup cytochrome CYPA1. The sex was determined using a molecular approach consisting in the genotyping sex-specific genes. CYPA1 was detected at the junction between epidermis and blubber on dolphins only, mostly in the endothelial cells. Similar observation was obtained in the dermis of one M. novaeangliae. Immunohistochemical slides were scored to evaluate the expression of the CYPA1 and a higher expression was observed in S. longirostris, suggesting a higher exposure to pollutants for this species. The difference of expression between sexes was not significant. 相似文献
104.
William L. Bandy Fran?ois Michaud Carlos A. Mortera Guti��rrez J��r?me Dyment Jacques Bourgois Jean-Yves Royer Thierry Calmus Marc Sosson Jose Ortega-Ramirez 《Pure and Applied Geophysics》2011,168(8-9):1391-1413
To better define the morphotectonic elements and tectonic development of the Mid-Rivera-Transform Discordance, multibeam bathymetric, seafloor backscatter, multichannel seismic reflection and total field marine magnetic data were collected along the entire Rivera Transform west of 107°W during the BART and FAMEX campaigns of the N.O. L??Atalante conducted in 2002. These data show that, although the transform tectonized zone of the Rivera Transform west of 107°30??W is a single continuous morphologic basin, this basin consists of two distinct morphotectonic domains: an eastern domain which morphologically is a deep rhombochasm within which organized seafloor spreading has occurred, and a western ??leaky transform?? domain. These new data, in conjunction with the results of previous studies, support the idea that the Rivera-Pacific Euler pole is migrating southward towards the eastern half of the Rivera Transform, and further indicate a recent (<0.14?Ma), and most likely ongoing, clockwise reorganization of the principle transform displacement zones of the Rivera Transform west of 108°W. We propose that the Mid-Rivera-Transform Discordance owes its origin to this eastward progressing, clockwise reorganization of the transform segments that is occurring in response to recent changes in Rivera-Pacific relative plate motion. 相似文献
105.
P. Huybrechts H. Goelzer I. Janssens E. Driesschaert T. Fichefet H. Goosse M.-F. Loutre 《Surveys in Geophysics》2011,32(4-5):397-416
Calculations were performed with the Earth system model of intermediate complexity LOVECLIM to study the response of the Greenland and Antarctic ice sheets to sustained multi-millennial greenhouse warming. Use was made of fully dynamic 3D thermomechanical ice-sheet models bidirectionally coupled to an atmosphere and an ocean model. Two 3,000-year experiments were evaluated following forcing scenarios with atmospheric CO2 concentration increased to two and four times the pre-industrial value, and held constant thereafter. In the high concentration scenario the model shows a sustained mean annual warming of up to 10°C in both polar regions. This leads to an almost complete disintegration of the Greenland ice sheet after 3,000 years, almost entirely caused by increased surface melting. Significant volume loss of the Antarctic ice sheet takes many centuries to initiate due to the thermal inertia of the Southern Ocean but is equivalent to more than 4 m of global sea-level rise by the end of simulation period. By that time, surface conditions along the East Antarctic ice sheet margin take on characteristics of the present-day Greenland ice sheet. West Antarctic ice shelves have thinned considerably from subshelf melting and grounding lines have retreated over distances of several 100 km, especially for the Ross ice shelf. In the low concentration scenario, corresponding to a local warming of 3?C4°C, polar ice-sheet melting proceeds at a much lower rate. For the first 1,200 years, the Antarctic ice sheet is even slightly larger than today on account of increased accumulation rates but contributes positively to sea-level rise after that. The Greenland ice sheet loses mass at a rate equivalent to 35 cm of global sea level rise during the first 1,000 years increasing to 150 cm during the last 1,000 years. For both scenarios, ice loss from the Antarctic ice sheet is still accelerating after 3,000 years despite a constant greenhouse gas forcing after the first 70?C140 years of the simulation. 相似文献
106.
Emmanuel Fritsch Etienne Balan Nadia Régina Do Nascimento Thierry Allard Marion Bardy Guilherme Bueno Sylvie Derenne Adolpho José Melfi Georges Calas 《Comptes Rendus Geoscience》2011,343(2-3):188-198
This article reports major results from collaborative research between France and Brazil on soil and water systems, carried out in the Upper Amazon Basin. It reveals the weathering processes acting in the partly inundated, low elevation plateaus of the Basin, mostly covered by evergreen forest. Our findings are based on geochemical data and mineral spectroscopy that probe the crystal chemistry of Fe and Al in mineral phases (mainly kaolinite, Al- and Fe-(hydr)oxides) of tropical soils (laterites). These techniques reveal crystal alterations in mineral populations of different ages and changes of metal speciation associated with mineral or organic phases. These results provide an integrated model of soil formation and changes (from laterites to podzols) in distinct hydrological compartments of the Amazon landscapes and under altered water regimes. 相似文献
107.
As marine spatial planning is developing, prompted by the European Union through common principles prescribed in a road map, it is important to disseminate and analyse what has been put forward as the French experience in this field. Hence, the experience of the schémas de mise en valeur de la mer immediately proves to be original in its framework and deeply rooted in French specificities. However, a further analysis of this procedure implemented over several decades highlights the perspectives that would be worth integrating into French and European considerations. This paper thus provides information referring to the SMVM experience, presents an analysis of its results, and attempts to draw lessons from it with regard to recent developments in French marine policy. 相似文献
108.
FIRST RESULTS FROM VIRGO,THE EXPERIMENT FOR HELIOSEISMOLOGY AND SOLAR IRRADIANCE MONITORING ON SOHO 总被引:1,自引:0,他引:1
Fröhlich Claus Andersen Bo N. Appourchaux Thierry Berthomieu Gabrielle Crommelynck Dominique A. Domingo Vicente Fichot Alain Finsterle Wolfgang Gómez Maria F. Gough Douglas Jiménez Antonio Leifsen Torben Lombaerts Marc Pap Judit M. Provost Janine Roca Cortés Teodoro Romero José Roth Hansjörg Sekii Takashi Telljohann Udo Toutain Thierry Wehrli Christoph 《Solar physics》1997,170(1):1-25
First results from the VIRGO experiment (Variability of solar IRradiance and Gravity Oscillations) on the ESA/NASA Mission SOHO (Solar and Heliospheric Observatory) are reported. The observations started mid-January 1996 for the radiometers and sunphotometers and near the end of March for the luminosity oscillation imager. The performance of all the instruments is very good, and the time series of the first 4–6 months are evaluated in terms of solar irradiance variability, solar background noise characteristics and p-mode oscillations. The solar irradiance is modulated by the passage of active regions across the disk, but not all of the modulation is straightforwardly explained in terms of sunspot flux blocking and facular enhancement. Helioseismic inversions of the observed p-mode frequencies are more-or-less in agreement with the latest standard solar models. The comparison of VIRGO results with earlier ones shows evidence that magnetic activity plays a significant role in the dynamics of the oscillations beyond its modulation of the resonant frequencies. Moreover, by comparing the amplitudes of different components ofp -mode multiplets, each of which are influenced differently by spatial inhomogeneity, we have found that activity enhances excitation. 相似文献
109.
Gerta KELLER Thierry ADATTE Wolfgang STINNESBECK Doris STüBEN Zsolt BERNER Utz KRAMAR Markus HARTING 《Meteoritics & planetary science》2004,39(7):1127-1144
Abstract Yaxcopoil‐1 (Yax‐1), drilled within the Chicxulub crater, was expected to yield the final proof that this impact occurred precisely 65 Myr ago and caused the mass extinction at the Cretaceous‐Tertiary (K/T) boundary. Instead, contrary evidence was discovered based on five independent proxies (sedimentologic, biostratigraphic, magnetostratigraphic, stable isotopic, and iridium) that revealed that the Chicxulub impact predates the K/T boundary by about 300,000 years and could not have caused the mass extinction. This is demonstrated by the presence of five bioturbated glauconite layers and planktic foraminiferal assemblages of the latest Maastrichtian zone CF1 and is corroborated by magnetostratigraphic chron 29r and characteristic late Maastrichtian stable isotope signals. These results were first presented in Keller et al. (2004). In this study, we present more detailed evidence of the presence of late Maastrichtian planktic foraminifera, sedimentologic, and mineralogic analyses that demonstrate that the Chicxulub impact breccia predates the K/T boundary and that the sediments between the breccia and the K/T boundary were deposited in a normal marine environment during the last 300,000 years of the Cretaceous. 相似文献
110.
Results of an experimental study of the oxidation of a zirconium plasma generated by laser ablation of a metallic target under low pressures of oxygen are presented. The crystallographic identification of the collected product by electronic diffraction shows metastable ZrO cubic phase. The oxidation phenomena are interpreted by thermochemical simulation suggesting a model in accordance with other cases of synthesis of metastable oxides at high temperatures, such as plasma reactors. 相似文献