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Date submitted2008-10-10
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Date accepted2008-12-13
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Date published2009-12-11
Magnetotelluric evidence of deep geodynamic settings at the junction zone of the Southern Tien Shan and Tarim basin
Detailed magnetotelluric and magnetovariation profiling was conducted (40 broadband stations) at the southern 140 km segment of geophysical transect MANAS with the help of MT instruments: MTU-5 (produced by «Phoenix Geophysics Ltd») and MT-24 (produced by EMI Center). MANAS transect extended from south of Kashgar, China, to just south of Bishkek, Kyrgyzstan and crossing the whole Tien Shan orogenic belt in transverse direction of its main ranges strike. We constructed 2D geoelectric model to characterize block-fracture structure at the junction zone of the Southern Tien Shan. There is low resistive inclined zone in the obtained cross-section imaging the underthrusting process of Tarim tectonic sheets under the Tien Shan mountains. Also there are some electrical heterogeneities as indications that young deformations inside Tarim lithospheric block have the whole crust scale.
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Date submitted1951-07-01
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Date accepted1951-09-16
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Date published1952-12-23
On the calculation of eigenvalues by the method of steepest descent
- Authors:
- M. Sh. Birman
L. V. Kantorovich proposed a new direct method for solving problems of the calculus of variations, which he called the steepest descent method. As L. V. Kantorovich showed, the method can be successfully used for the approximate solution of linear functional equations in a Hilbert space. In addition, L. V. Kantorovich applied the steepest descent method to the problem of eigenvalues of completely continuous operators. In application to this problem, the method consists of the following. In this note, a proof of the convergence of the process is given without the assumption of closeness of x0 to x*. In addition, a comparison of the steepest descent method with the known iterative method for calculating eigenvalues is made, and a multi-step version of the method under consideration is investigated. In what follows, the assumption that m = 0 is not used.