全文获取类型
收费全文 | 4015篇 |
免费 | 1087篇 |
国内免费 | 107篇 |
专业分类
测绘学 | 15篇 |
大气科学 | 5篇 |
地球物理 | 4106篇 |
地质学 | 800篇 |
海洋学 | 157篇 |
天文学 | 8篇 |
综合类 | 35篇 |
自然地理 | 83篇 |
出版年
2024年 | 19篇 |
2023年 | 62篇 |
2022年 | 95篇 |
2021年 | 77篇 |
2020年 | 144篇 |
2019年 | 150篇 |
2018年 | 124篇 |
2017年 | 149篇 |
2016年 | 156篇 |
2015年 | 151篇 |
2014年 | 271篇 |
2013年 | 181篇 |
2012年 | 129篇 |
2011年 | 184篇 |
2010年 | 184篇 |
2009年 | 246篇 |
2008年 | 262篇 |
2007年 | 216篇 |
2006年 | 229篇 |
2005年 | 200篇 |
2004年 | 168篇 |
2003年 | 164篇 |
2002年 | 195篇 |
2001年 | 135篇 |
2000年 | 141篇 |
1999年 | 124篇 |
1998年 | 138篇 |
1997年 | 125篇 |
1996年 | 169篇 |
1995年 | 150篇 |
1994年 | 104篇 |
1993年 | 106篇 |
1992年 | 57篇 |
1991年 | 47篇 |
1990年 | 42篇 |
1989年 | 28篇 |
1988年 | 23篇 |
1987年 | 17篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 11篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1954年 | 6篇 |
排序方式: 共有5209条查询结果,搜索用时 9 毫秒
171.
Kinetic shear resistance,fluid pressures and radiation efficiency during seismic faulting 总被引:1,自引:0,他引:1
Richard H. Sibson 《Pure and Applied Geophysics》1977,115(1-2):387-400
Summary During earthquake faulting, radiation efficiency and the degree stress relief are critically dependent on the kinetic shear resistance. This is often assumed to stay constant during slip, but geological evidence suggests that for moderate or large shallow earthquakes it may decrease dramatically to near-zero values once slip is initiated, either by melt formation or by transient increases in fluid pressure on the fault plane. The latter, probably more common process may arise partly through an interaction between temperature and water pressure, and partly through dilatancy recovery as shear stress is relieved. If the fault remains undrained, stress relief should be absolute with seismic efficiency reaching high values, so that stress drops give a measure of the level of tectonic shear stress in fault zones. Supporting evidence comes from the observation that apparent stress is generally about half the stress drop. 相似文献
172.
N. Mantajit 《Environmental Geology》2000,39(7):750-752
The paper describes the activities and objectives of the Department of Mineral Resources in the field of environmental geology.
This approach is still a comparatively new for Thailand and presently comprises different programs: environmental geology
for regional planning, seismic hazards, flooding/landslides, coastal management and geosites conservation. The Environmental
Geology Section of the Department is the relevant administrative unit. The technical work and the related documentations focus
on rising public awareness and integration of geo-information into land-use planning and land development.
Received: 23 April 1999 · Accepted: 8 June 1999 相似文献
173.
Stability of earthquake moment tensor inversions: effect of the double-couple constraint 总被引:1,自引:0,他引:1
We show that spurious large non-double-couple components can be obtained in inversions for the full deviatoric moment tensor for shallow crustal earthquakes due to inaccurate Earth models. The traditional “best double-couple” solution does not in general provide an optimal estimate of a double-couple mechanism, and is only reliable when the non-double-couple component of the full deviatoric solution is small. The inverse problem for the moment tensors of the 1998 Antarctic Plate and 2000 Wharton Basin strike-slip earthquakes is shown in each case to have two well-fitting minima in the misfit function of pure double-couple solutions. Such pairs of solutions are most likely to exist for earthquakes which are close either to vertical strike-slip or to dip-slip on a fault plane dipping at 45°. It is shown theoretically that these pairs of solutions arise from the combination of the pure double-couple constraint and the instability of two elements of the moment tensor. No significant non-double-couple component is found for the shallow thrusting 1996 Biak, Indonesia earthquake. 相似文献
174.
本文通过分析福州、小陶地震的波形记录及各种定位参数 ,总结了该地区的震相特征和各台的震级情况 ,结合地震速报的规程 ,提出了对这两个地区地震速报的建议。 相似文献
175.
Ewald Lüschen Daniela Borrini Helmut Gebrande Bernd Lammerer Karl Millahn Franz Neubauer Rinaldo Nicolich TRANSALP Working Group 《Tectonophysics》2006,414(1-4):9
The TRANSALP consortium, comprising institutions from Italy, Austria and Germany, carried out deep seismic reflection measurements in the Eastern Alps between Munich and Venice in 1998, 1999 and 2001. In order to complement each other in resolution and depth range, the Vibroseis technique was combined with simultaneous explosive source measurements. Additionally, passive cross-line recording provided three-dimensional control and alternative north–south sections. Profits were obtained by the combination of the three methods in sectors or depths where one method alone was less successful.The TRANSALP sections clearly image a thin-skinned wedge of tectonic nappes at the northern Alpine front zone, unexpected graben or half-graben structures within the European basement, and, thick-skinned back-thrusting in the southern frontal zone beneath the Dolomite Mountains. A bi-vergent structure at crustal scale is directed from the Alpine axis to the external parts. The Tauern Window obviously forms the hanging wall ramp anticline above a southward dipping, deep reaching reflection pattern interpreted as a tectonic ramp along which the Penninic units of the Tauern Window have been up-thrusted.The upper crystalline crust appears generally transparent. The lower crust in the European domain is characterized by a 6–7 km thick laminated structure. On the Adriatic side the lower crust displays a much thicker or twofold reflective pattern. The crustal root at about 55 km depth is shifted around 50 km to the south with respect to the main Alpine crest. 相似文献
176.
地震勘探在山东蓬家夼金矿深部预测中的应用 总被引:2,自引:0,他引:2
在分析了石油地震与金属矿地震不同点的基础上,简介了地震勘探方法的基本原理,并通过在山东蓬家夼金矿的实际应用,得到了理想的效果,为隐伏矿床的精确定位预测提供了十分重要的地球物理资料。 相似文献
177.
178.
收集云南地区井水温数字化观测资料,对比分析了2011年3月11日日本9.0级和2008年5月12日汶川8.0级2次地震引起的云南地区井水温同震响应特征。结果表明,不同构造区域的观测井的井水温同震响应存在差异,主要与井孔本身的特征和区域构造环境有关;同一口观测井对不同地震引起的水温响应变化形态基本一致,不受地震方位和震源机制的影响,井水温同震下降或上升响应幅度随震级的增大而增大,随震中距的增大而减小;井水温同震响应的机理主要是在地震波的作用下,观测井孔中的水体受震荡激发而加速对流与掺混导致水温发生变化,当地震波逐渐平息,探头附近的井水温逐步恢复。 相似文献
179.
180.