全文获取类型
收费全文 | 309篇 |
免费 | 17篇 |
专业分类
测绘学 | 5篇 |
大气科学 | 34篇 |
地球物理 | 76篇 |
地质学 | 113篇 |
海洋学 | 24篇 |
天文学 | 44篇 |
综合类 | 1篇 |
自然地理 | 29篇 |
出版年
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 14篇 |
2019年 | 15篇 |
2018年 | 13篇 |
2017年 | 23篇 |
2016年 | 29篇 |
2015年 | 26篇 |
2014年 | 15篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 24篇 |
2010年 | 10篇 |
2009年 | 19篇 |
2008年 | 10篇 |
2007年 | 14篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1990年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有326条查询结果,搜索用时 15 毫秒
121.
The study of earthquake swarms and their characteristics can improve our understanding of the transient processes that provoke seismic crises. The spatio-temporal process of the energy release is often linked with changes of statistical properties, and thus, seismicity parameters can help to reveal the underlying mechanism in time and space domains. Here, we study the Torreperogil–Sabiote 2012–2013 seismic series (southern Spain), which was relatively long lasting, and it was composed by more than 2000 events. The largest event was a magnitude 3.9 event which occurred on February 5, 2013. It caused slight damages, but it cannot explain the occurrence of the whole seismic crises which was not a typical mainshock–aftershock sequence. To shed some light on this swarm occurrence, we analyze the change of statistical properties during the evolution of the sequence, in particular, related to the magnitude and interevent time distributions. Furthermore, we fit a modified version of the epidemic type aftershock sequence (ETAS) model in order to investigate changes of the background rates and the trigger potential. Our results indicate that the sequence was driven by an aseismic transient stressing rate and that the system passes after the swarm occurrence to a new forcing regime with more typical tectonic characteristics. 相似文献
122.
Ocean Dynamics - A three-dimensional, regional coupled ice-ocean model based on the open-source Community Earth System Model has been developed and implemented for the Baltic Sea. The model... 相似文献
123.
Arne Lohrberg Klaus Schwarzer Daniel Unverricht Andreas Omlin Sebastian Krastel 《第四纪科学杂志》2020,35(7):892-906
Tunnel valleys are assumed to form near the margin of ice sheets. Hence, they can be used to reconstruct the dynamics of former ice margins. The detailed formation and infill of tunnel valleys, however, are still not well understood. Here, we present a dense grid of high-resolution 2D multi-channel reflection seismic data from the German sector of the southeastern North Sea imaging tunnel valleys in very great detail. Three tunnel valley systems were traced over distances ranging between 11 and 21 km. All tunnel valleys are completely filled and buried. They differ in incision depth, incision width and number of incisions. The tunnel valleys cut 130–380 m deep into Neogene, Palaeogene and Cretaceous sediments; they show a lower V-shaped and an upper U-shaped morphology. For individual tunnel valleys, the overall incision direction ranges from east–west to northeast–southwest. Two tunnel valleys intersect at an oblique angle without reuse of the thalweg. These valleys incise into a pre-existing glaciotectonic complex consisting of thrust sheets in the northwest of the study area. The analysis of the glaciotectonic complex and the tunnel valleys leads us to assume that we identified several marginal positions of (pre-)Elsterian ice lobes in the southeastern North Sea. 相似文献
124.
Thomas Kenkmann Sebastian Sturm Tim Krüger Elias Salameh Marwan Al‐Raggad Khalil Konsul 《Meteoritics & planetary science》2017,52(7):1351-1370
The investigation of terrestrial impact structures is crucial to gain an in‐depth understanding of impact cratering processes in the solar system. Here, we use the impact structure Jebel Waqf as Suwwan, Jordan, as a representative for crater formation into a layered sedimentary target with contrasting rheology. The complex crater is moderately eroded (300–420 m) with an apparent diameter of 6.1 km and an original rim fault diameter of 7 km. Based on extensive field work, IKONOS imagery, and geophysical surveying we present a novel geological map of the entire crater structure that provides the basis for structural analysis. Parametric scaling indicates that the structural uplift (250–350 m) and the depth of the ring syncline (<200 m) are anomalously low. The very shallow relief of the crater along with a NE vergence of the asymmetric central uplift and the enhanced deformations in the up‐range and down‐range sectors of the annular moat and crater rim suggest that the impact was most likely a very oblique one (~20°). One of the major consequences of the presence of the rheologically anisotropic target was that extensive strata buckling occurred during impact cratering both on the decameter as well as on the hundred‐meter scale. The crater rim is defined by a circumferential normal fault dipping mostly toward the crater. Footwall strata beneath the rim fault are bent‐up in the down‐range sector but appear unaffected in the up‐range sector. The hanging wall displays various synthetic and antithetic rotations in the down‐range sector but always shows antithetic block rotation in the up‐range sector. At greater depth reverse faulting or folding is indicated at the rim indicating that the rim fault was already formed during the excavation stage. 相似文献
125.
Alejandro Guzmán Emanuele Perinati Sebastian Diebold Chris Tenzer Andrea Santangelo 《Experimental Astronomy》2017,44(3):401-411
The scattering of soft protons inside the Wolter-type optics of X-ray observatories has been proven to concentrate these particles onto the focal plane instruments. The funneling of these protons increases the instrumental background and can also contribute to the degrading of the detectors. The instrumental background and degradation of the detector’s performance experienced by Chandra and XMM-Newton is significantly larger than what was expected on the basis of previous Monte Carlo simulations. For Chandra the main issue is the degradation of the energy resolution due to lattice displacements in the detectors. For XMM the contribution to the instrumental background is more significant. In between, new laboratory measurements as well as a revision of the theory are needed to correctly assess the impact of the environmental radiation for future missions. In this publication we present a Geant4 class that will allow future users to select between either theoretical models or measured data to simulate the scattering of soft protons at grazing angles. To develop this method, we revisit the theory of elastic scattering of protons on polished surfaces and implement these approaches into Geant4. We also implemented recently performed measurements using parts of eROSITA (extended ROentgen Survey with an Imaging Telescope Array) mirror shells as scattering targets as another scattering model to be used within the Geant4 toolkit. 相似文献
126.
127.
Perelet Alexei O. Gultepe Ismail Hoch Sebastian W. Pardyjak Eric R. 《Boundary-Layer Meteorology》2021,181(2-3):295-315
Boundary-Layer Meteorology - We investigate the path-averaged visibility and discrimination of fog and rain events using a two-wavelength (near-infrared and microwave) scintillometer system. These... 相似文献
128.
A clear and present danger: Ladakh's increasing vulnerability to flash floods and debris flows 下载免费PDF全文
Alan D. Ziegler Sebastian I. Cantarero Robert J. Wasson Pradeep Srivastava Sonam Spalzin Winston T. L. Chow Jamie Gillen 《水文研究》2016,30(22):4214-4223
This preliminary investigation of the recent spate of deadly flash floods and debris flows in Ladakh (India) over the last decade identifies uncontrolled development in hazardous locations as an important factor contributing to loss of life and property damage in this high mountain desert. The sediments exposed in the channel banks and on the alluvial fans of several mountain streams in the area indicate a long history of flash floods and debris flows resulting from intense storms, which appear to have increased in frequency within the last decade. The signposts of these recurrent hazards are being ignored as a growing economy, which is boosted by a well‐established tourism industry, is now driving development onto lands that are susceptible to floods and debris flow hazards. In this science briefing we argue that the increasing vulnerability in Ladakh should be addressed with sound disaster governance strategies that are proactive, rather than reactionary. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
129.
130.
Jacob Geersen David Völker Jan H. Behrmann Dirk Kläschen Wilhelm Weinrebe Sebastian Krastel Christian Reichert 《地学学报》2013,25(6):472-477
Determining factors that limit coseismic rupture is important to evaluate the hazard of powerful subduction zone earthquakes such as the 2011 Tohoku‐Oki event (Mw = 9.0). In 1960 (Mw = 9.5) and 2010 (Mw = 8.8), Chile was hit by such powerful earthquakes, the boundary of which was the site of a giant submarine slope failure with chaotic debris subducted to seismogenic zone depth. Here, a continuous décollement is absent, whereas away from the slope failure, a continuous décollement is seismically imaged. We infer that underthrusting of inhomogeneous slide deposits prevents the development of a décollement, and thus the formation of a thin continuous slip zone necessary for earthquake rupture propagation. Thus, coseismic rupture during the 1960 and 2010 earthquakes seems to be limited by underthrusted upper plate mass‐wasting deposits. More generally, our results suggest that upper plate dynamics and resulting surface processes can play a key role for determining rupture size of subduction zone earthquakes. 相似文献