全文获取类型
收费全文 | 125篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
大气科学 | 16篇 |
地球物理 | 31篇 |
地质学 | 59篇 |
海洋学 | 14篇 |
天文学 | 5篇 |
综合类 | 1篇 |
自然地理 | 9篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 20篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 13篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1993年 | 2篇 |
1988年 | 1篇 |
排序方式: 共有135条查询结果,搜索用时 15 毫秒
91.
Predictability of the mid-latitude Atlantic meridional overturning circulation in a multi-model system 总被引:1,自引:1,他引:0
Holger Pohlmann Doug M. Smith Magdalena A. Balmaseda Noel S. Keenlyside Simona Masina Daniela Matei Wolfgang A. Müller Philippe Rogel 《Climate Dynamics》2013,41(3-4):775-785
Assessing the skill of the Atlantic meridional overturning circulation (AMOC) in decadal hindcasts (i.e. retrospective predictions) is hampered by a lack of observations for verification. Models are therefore needed to reconstruct the historical AMOC variability. Here we show that ten recent oceanic syntheses provide a common signal of AMOC variability at 45°N, with an increase from the 1960s to the mid-1990s and a decrease thereafter although they disagree on the exact magnitude. This signal correlates with observed key processes such as the North Atlantic Oscillation, sub-polar gyre strength, Atlantic sea surface temperature dipole, and Labrador Sea convection that are thought to be related to the AMOC. Furthermore, we find potential predictability of the mid-latitude AMOC for the first 3–6 year means when we validate decadal hindcasts for the past 50 years against the multi-model signal. However, this predictability is not found in models driven only by external radiative changes, demonstrating the need for initialization of decadal climate predictions. 相似文献
92.
93.
94.
Magdalena Falco Andrea F. Carril Laurent Z. X. Li Carlos Cabrelli Claudio G. Menndez 《Climate Dynamics》2020,54(3):1553-1569
This paper aims to identify those regions within the South American continent where the Regional Climate Models (RCMs) have the potential to add value (PAV) compared to their coarser-resolution global forcing. For this, we used a spatial-scale filtering method based on the wavelet theory to distinguish the regional climatic signal present in atmospheric surface fields from observed data (CPC and TRMM) and 6 RCM simulations belonging to the CORDEX Project. The wavelet used for filtering was Haar wavelet, but a comparative analysis with Daubechies 4 wavelet indicated that meteorological fields or regional indices were not very sensitive to the wavelet selected. Once the longer wavelengths were filtered, we focused on analyzing the spatial variability of extreme rainfall and the spatiotemporal variability of maximum and minimum surface air temperature on a daily basis. The results obtained suggest essential differences in the spatial distribution of the small-scale signal of extreme precipitation between TRMM and regional models, together with a large dispersion between models. While TRMM and CPC register a large signal throughout the continent, the RCMs place it over the Andes Cordillera and some over tropical South America. PAV signal for surface air temperature was found over the Andes Cordillera and the Brazilian Highlands, which are regions characterized by complex topography, and also on the coasts of the continent. The signal came specially from the small-scale stationary component. The transient part is much smaller than the stationary one, except over la Plata Basin where they are of the same order of magnitude. Also, the RCMs and CPC showed a large spread between them in representing this transient variability. The results confirm that RCMs have the potential to add value in the representation of extreme precipitation and the mean surface temperature in South America. However, this condition is not applicable throughout the whole continent but is particularly relevant in those terrestrial regions where the surface forcing is strong, such as the Andes Cordillera or the coasts of the continent. 相似文献
95.
Deep 3D thermal modelling for the city of Berlin (Germany) 总被引:1,自引:1,他引:0
Judith Sippel Sven Fuchs Mauro Cacace Anna Braatz Oliver Kastner Ernst Huenges Magdalena Scheck-Wenderoth 《Environmental Earth Sciences》2013,70(8):3545-3566
This study predicts the subsurface temperature distribution of Germany’s capital Berlin. For this purpose, a data-based lithosphere-scale 3D structural model is developed incorporating 21 individual geological units. This model shows a horizontal grid resolution of (500 × 500) m and provides the geometric base for two different approaches of 3D thermal simulations: (1) calculations of the steady-state purely conductive thermal field and (2) simulations of coupled fluid flow and heat transport. The results point out fundamentally different structural and thermal configurations for potential geothermal target units. The top of the Triassic Middle Buntsandstein strongly varies in depth (159–2,470 m below sea level) and predicted temperatures (15–95 °C), mostly because of the complex geometry of the underlying Permian Zechstein salt. The top of the sub-salt Sedimentary Rotliegend is rather flat (2,890–3,785 m below sea level) and reveals temperatures of 85–139 °C. The predicted 70 °C-isotherm is located at depths of about 1,500–2,200 m, cutting the Middle Buntsandstein over large parts of Berlin. The 110 °C-isotherm at 2,900–3,700 m depth widely crosscuts the Sedimentary Rotliegend. Groundwater flow results in subsurface cooling the extent of which is strongly controlled by the geometry and the distribution of the Tertiary Rupelian Clay. The cooling effect is strongest where this clay-rich aquitard is thinnest or missing, thus facilitating deep-reaching forced convective flow. The differences between the purely conductive and coupled models highlight the need for investigations of the complex interrelation of flow- and thermal fields to properly predict temperatures in sedimentary systems. 相似文献
96.
Peter Schmid-Beurmann Luisa Ottolini Frédéric Hatert Thorsten Geisler Magdalena Huyskens Volker Kahlenberg 《Mineralogy and Petrology》2013,107(4):501-515
The topotactic oxidation and delithiation reaction from triphylite, Li(Fe,Mn)PO4, leading to ferrisicklerite, Li<1(Fe3+,Mn2+)PO4, was investigated under hydrothermal conditions. A cuboid cut from a triphylite single-crystal (Palermo Mine, New Hampshire, USA) with the composition Li0.93(3)(Fe2+ 0.733(6),Fe3+ 0.015(1),Mn2+ 0.210(4),Mg0.063(2))1.021(8)P1.00(2)O4 in addition with ground bulk material were treated with KMnO4 and 30 % H2O2(aq) as oxidizing agent in a 0.1 N hydrochloric acid solution in the temperature range between 60 and 200 °C. At 120 °C a rim of 0.1 mm thickness of ferrisicklerite had formed around the core of unreacted triphylite. The sharp reaction boundary was clearly visible, due to the reddish brown absorption colors of ferrisicklerite, compared to colorless triphylite. Using single-crystal X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), electron probe micro-analysis (EPMA) and 57Fe-Mössbauer spectroscopy the product ferrisicklerite was characterized and its composition determined as Li0.30(7)(Fe2+ 0.049(1)Fe3+ 0.65(2)Mn2+ 0.218(5)Mg0.062(2))0.98(1)P1.01(3)O4, with unit cell parameters a?=?4.795(1), b?=?9.992(4), and c?=?5.886(2) Å. EPMA investigations across the reaction boundary showed no changes in the concentrations of Fe, Mn, Mg, and P. In contrast, SIMS measurements clearly proved the delithiated state of the ferrisicklerite product. Polarization microscopy revealed that the orientation of the ferrisicklerite rim was the same as that of the original triphylite single-crystal, confirming the strictly topotactic character of the reaction. 相似文献
97.
Yvonne Sawall Jamaluddin Jompa Magdalena Litaay Andi Maddusila Claudio Richter 《Marine pollution bulletin》2013
Coral recruitment was assessed in highly diverse and economically important Spermonde Archipelago, a reef system subjected to land-based sources of siltation/pollution and destructive fishing, over a period of 2 years. Recruitment on settlement tiles reached up to 705 spat m−2 yr−1 and was strongest in the dry season (July–October), except off-shore, where larvae settled earlier. Pocilloporidae dominated near-shore, while a more diverse community of Acroporidae, Poritidae and others settled in the less polluted mid-shelf and off-shore reefs. Non-coral fouling community appeared to hardly influence initial coral settlement on the tiles, although, this does not necessarily infer low coral post-settlement mortality, which may be enhanced at the near- and off-shore reefs as indicated by increased abundances of potential space competitors on natural substrate. Blast fishing showed no local reduction in coral recruitment and live hard coral cover increased in oligotrophic reefs, indicating potential for coral recovery, if managed effectively. 相似文献
98.
Reconstruction of landscape paleohydrology using the sediment archives of three dystrophic lakes in northeastern Poland 总被引:1,自引:0,他引:1
Danuta Drzymulska Magdalena Fiłoc Mirosława Kupryjanowicz 《Journal of Paleolimnology》2014,51(1):45-62
Sediment layers of uniform age within lakes (isochrones) and their patterns reflect accumulation processes which can be correlated with hydrologic conditions in lake basins. The sedimentary archives in three small dystrophic lakes in northeastern Poland are described based on the correlation of local pollen assemblage zones in cores that were collected from the centers and margins of each lake. Past regional groundwater levels could be discerned from the shape of the isochrones, whether plane parallel or concave in configuration in relation to the lake basin shape. The concave configuration of the isochrones in the studied lakes shows that regional groundwater levels remained mostly high and stable throughout their history. The water levels in each lake during the Late Glacial and throughout the Holocene were different and no single, common water-level fluctuation pattern was identified in the three water bodies. The lack of such a finding suggests that the lakes are influenced dominantly by local hydrological factors. 相似文献
99.
Tamara Markovic Slobodan Miko Sanja Kapelj Renato Buljan Ozren Larva Zoran Peh 《Journal of Geochemical Exploration》2006,88(1-3):124
The Croatian south part of the country is mainly composed of strongly krastified carbonate rocks. Also in this south part of Croatia is lacking of large depressions and poljes with thick covers. Some karst poljes and depressions may have thick covers, like for example the Vransko polje. The Vransko polje is characterised by an intensive agricultural activity. At the centre of the polje is located a karst spring (Turanjsko jezero), which is used for the water supply of the town Biograd and its surroundings. Total metals, nutrients (nitrate, ammonia, phosphate), organic matter content and cation exchange capacity (CEC) were measured in soil samples collected from the polje. Metals and nutrients were also measured in the water samples of channel Kotarka (which is passing through the area) and three springs (Turanjsko jezero, Kakma and Tinj). Measured total concentrations of metals of soil samples were treated by R-cluster multivariate statistical analysis. The result of statistical analysis showed grouping of metals with similar behaviour. Content of metals and nutrients were low in the spring samples but high in the water sample of the channel Kotarka, because the channel drains the water from the surroundings. Although agricultural activity in the Vransko polje is high, there is no high anthropogenic influence on groundwater and soil. They are both of good quality. 相似文献
100.
A 3D backstripping approach considering salt flow as a consequence of spatially changing overburden load distribution, isostatic rebound and sedimentary compaction for each backstripping step is used to reconstruct the subsidence history in the Northeast German Basin. The method allows to determine basin subsidence and the salt-related deformation during Late Cretaceous–Early Cenozoic inversion and during Late Triassic–Jurassic extension. In the Northeast German Basin, the deformation is thin-skinned in the basinal part, but thick-skinned at the basin margins. The salt cover is deformed due to Late Triassic–Jurassic extension and Late Cretaceous–Early Cenozoic inversion whereas the salt basement remained largely stable in the basin area. In contrast, the basin margins suffered strong deformation especially during Late Cretaceous–Early Cenozoic inversion. As a main question, we address the role of salt during the thin-skinned extension and inversion of the basin. In our modelling approach, we assume that the salt behaves like a viscous fluid on the geological time-scale, that salt and overburden are in hydrostatical near-equilibrium at all times, and that the volume of salt is constant. Because the basement of the salt is not deformed due to decoupling in the basin area, we consider the base of the salt as a reference surface, where the load pressure must be equilibrated. Our results indicate that major salt movements took place during Late Triassic to Jurassic E–W directed extension and during Late Cretaceous–Early Cenozoic NNE–SSW directed compression. Moreover, the study outcome suggests that horizontal strain propagation in the salt cover could have triggered passive salt movements which balanced the cover deformation by viscous flow. In the Late Triassic, strain transfer from the large graben systems in West Central Europe to the east could have caused the subsidence of the Rheinsberg Trough above the salt layer. In this context, the effective regional stress did not exceed the yield strength of the basement below the Rheinsberg Trough, but was high enough to provoke deformation of the viscous salt layer and its cover. During the Late Cretaceous–Early Cenozoic phase of inversion, horizontal strain propagation from the southern basin margin into the basin can explain the intensive thin-skinned compressive deformation of the salt cover in the basin. The thick-skinned compressive deformation along the southern basin margin may have propagated into the salt cover of the basin where the resulting folding again was balanced by viscous salt flow into the anticlines of folds. The huge vertical offset of the pre-Zechstein basement along the southern basin margin and the amount of shortening in the folded salt cover of the basin indicate that the tectonic forces responsible for this inversion event have been of a considerable magnitude. 相似文献