全文获取类型
| 收费全文 | 161篇 |
| 免费 | 14篇 |
| 国内免费 | 10篇 |
专业分类
| 地球物理 | 25篇 |
| 地质学 | 45篇 |
| 海洋学 | 1篇 |
| 综合类 | 1篇 |
| 自然地理 | 113篇 |
出版年
| 2023年 | 3篇 |
| 2022年 | 3篇 |
| 2021年 | 2篇 |
| 2020年 | 1篇 |
| 2019年 | 4篇 |
| 2018年 | 4篇 |
| 2017年 | 3篇 |
| 2016年 | 3篇 |
| 2015年 | 3篇 |
| 2014年 | 4篇 |
| 2013年 | 7篇 |
| 2012年 | 2篇 |
| 2011年 | 3篇 |
| 2010年 | 2篇 |
| 2009年 | 3篇 |
| 2008年 | 2篇 |
| 2007年 | 14篇 |
| 2006年 | 5篇 |
| 2005年 | 14篇 |
| 2004年 | 6篇 |
| 2003年 | 7篇 |
| 2002年 | 4篇 |
| 2001年 | 5篇 |
| 2000年 | 7篇 |
| 1999年 | 6篇 |
| 1998年 | 8篇 |
| 1997年 | 6篇 |
| 1996年 | 9篇 |
| 1995年 | 6篇 |
| 1994年 | 7篇 |
| 1993年 | 8篇 |
| 1992年 | 10篇 |
| 1991年 | 5篇 |
| 1990年 | 1篇 |
| 1988年 | 1篇 |
| 1987年 | 5篇 |
| 1986年 | 1篇 |
| 1979年 | 1篇 |
排序方式： 共有185条查询结果，搜索用时 0 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
Calculating the two-dimensional magnetotelluric Jacobian in finite elements using reciprocity 总被引：6，自引：0，他引：6
Patricia Pastana de Lugão Philip E. Wannamaker 《Geophysical Journal International》1996,127(3):806-810
To speed up the calculation of the field Jacobian for 2-D magnetoteliuric inversion using finite elements, the principle of electromagnetic reciprocity is applied. The governing relationship for the Jacobian of the field along strike is obtained by differentiating the Helmholtz equation with respect to the resistivity of each region in the finite-element mesh. The result is a similar Helmholtz equation for the Jacobian, with new sources distributed over all nodes within the parameter medium. However, according to the principle of electromagnetic reciprocity, the roles of sources and receivers are interchangeable. Utilizing reciprocity, the field values obtained from the original forward problem and for new unit sources imposed at the receivers are then utilized in the calculation of the Jacobian by simple multiplication and summation with finite-element terms at each rectangle in the mesh. For the auxiliary (across-strike) fields, the Jacobian terms are obtained by solving source vectors loaded with parabola coefficients used in the approximation to Maxwell's equations. Jacobian terms for the apparent resistivity ( p a ), the impedance phase (φ) and the vertical magnetic field ( K zy ) are then calculated utilizing the parallel- and auxiliary-field Jacobians. Comparison of Jacobian values obtained from reciprocity calculations and by differencing two forward solutions show that the reciprocity method is accurate and can be used to decrease the number of calculations required to obtain sensitivities by one to two orders of magnitude. 相似文献
9.
10.