全文获取类型
| 收费全文 | 126篇 |
| 免费 | 7篇 |
| 国内免费 | 36篇 |
专业分类
| 地球物理 | 27篇 |
| 地质学 | 58篇 |
| 海洋学 | 2篇 |
| 自然地理 | 82篇 |
出版年
| 2022年 | 1篇 |
| 2021年 | 4篇 |
| 2020年 | 4篇 |
| 2019年 | 1篇 |
| 2018年 | 3篇 |
| 2017年 | 4篇 |
| 2016年 | 1篇 |
| 2015年 | 3篇 |
| 2014年 | 1篇 |
| 2013年 | 6篇 |
| 2012年 | 8篇 |
| 2011年 | 4篇 |
| 2010年 | 1篇 |
| 2009年 | 3篇 |
| 2008年 | 5篇 |
| 2007年 | 10篇 |
| 2006年 | 14篇 |
| 2005年 | 11篇 |
| 2004年 | 9篇 |
| 2003年 | 6篇 |
| 2002年 | 5篇 |
| 2001年 | 6篇 |
| 2000年 | 6篇 |
| 1999年 | 12篇 |
| 1998年 | 2篇 |
| 1997年 | 9篇 |
| 1996年 | 9篇 |
| 1995年 | 5篇 |
| 1994年 | 6篇 |
| 1992年 | 5篇 |
| 1990年 | 2篇 |
| 1988年 | 1篇 |
| 1986年 | 2篇 |
排序方式： 共有169条查询结果，搜索用时 15 毫秒
21.
The dynamic problem in micropolar viscoelastic medium has been investigated by employing eigen value approach after applying
Laplace and Fourier transformations. An example of infinite space with concentrated force at the origin has been presented
to illustrate the application of the approach. The integral transforms have been inverted by using a numerical technique to
obtain the displacement components, force stresses, couple stress and microrotation in the physical domain. The results for
these quantities are given and illustrated graphically. 相似文献
22.
This work examines the propagation of time harmonic, horizontally polarized shear waves through a naturally occurring heterogeneous medium that exhibits viscous behaviour as well as random fluctuations of its elastic modulus about a mean value. As a first step, the governing equation, which is a heterogeneous Helmholtz equation, is solved using algebraic transformations and the relevant Green's function is obtained for two sets of boundary conditions, one corresponding to a finite depth layer and the other to an infinite layer. Viscous material behaviour is introduced by considering the depth-dependent elastic modulus to be a complex quantity. Subsequently, material stochasticity in the medium is handled through the perturbation approach by assuming that the elastic modulus has a small random fluctuation about its mean value. The final results are closed-form expressions for the mean value and covariance matrix of both the wave speed profile in the medium and the corresponding Green's function. In Part II, (Soil Dynam. Earth. Engng, 1996,15, 129-39), two examples concerning seismic wave propagation in soft topsoil and in sandstone serve to illustrate the methodology and comparisons are made with Monte Carlo simulations. 相似文献
23.
24.
Introduction It is found that there are some relationships between the thermal structures of subduction zones and the deep seismicity, while the mechanism relates the thermal structure and the deep seismicity is still unsure (Helffrich, Brodholt, 1991; Furukawa, 1994; Kirby, et al, 1996). From 1980s, geoscientists have constituted a series of numerical simulations on the stress states of subduction slabs. Based on the kinetic computation of Sung and Burns (1976a, b), Goto, et al (1983, 1987… 相似文献
25.
26.
27.
28.
29.
30.
基于谱元法计算理论,通过坐标旋转算法实现任意各向异性黏弹性介质中的地震波场计算,研究复合介质中地震波场特征。根据计算结果,qSV波表现为剪切滞弹性形变,qP波表现为膨胀滞弹性形变;品质因子不仅影响地震波振幅,还影响其传播频率;黏弹性介质吸收高频快,在一定频率范围内,黏弹性介质没有频散现象。 相似文献