德雷克海峡的扩张历史及其影响          下载免费PDF全文

吴水根  吕文正 《极地研究》1988,1(2):1-7

本文利用首次南大洋考察期间获得的德雷克海峡地球物理场资料,解释海峡海底板块扩张历史以及海峡扩张对南极环境形成的影响.  相似文献   

The field lines of an axisymmetric magnetic field     

George E. Backus 《Geophysical Journal International》1988,93(3):413-417

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辽东半岛南部震旦-寒武系界限剖面古地磁特征     

蓝晶 《国土资源》1988,(2)

在辽东半岛南部震旦-寒武系界限剖面中采集了32块古地磁岩石标本。古地磁测试结果表明:①辽东半岛南部震旦系兴民村期曾出现一次极性倒转,它发生在650Ma左右,可称之为兴民村反极性期,据此,可与国外上先寒武系对比;②本区震旦-寒武系沉积地层曾经历了中纬度→低纬度→中纬度的古地理纬度区的变化历史;③初步建立了辽东半岛南部震旦-寒武系界限附近地层的视古地磁极迁移轨迹。根据古地磁测试结果,结合本区地层特征,将震旦-寒武系界限定在兴民村组与葛屯组之间,兴民村组的顶为震旦系的上限,葛屯组的底为寒武系的下限。  相似文献   

在磁场条件下恒星大气Stokes轮廓特征量的研究     

屈中权  宣家余  丁有济  叶式煇 《天文研究与技术》1993,(3)

本文根据偏振辐射转移方程组就形成于有磁场的恒星大气中的Stokes轮廓的一些特征量与磁场强度大小的关系从理论上进行了探讨。结果表明:在强场情形下,L,Q,U,V的绝对值在非常靠近Zeeman分裂量±Δλ_H处达到极大;Hale的测量方法给出了总的场强的很好量度。最后用合成轮廓作出了相应的检验。  相似文献   

流动形变及重磁综合监测断层的研究     

车兆宏  巩曰沐 《大地测量与地球动力学》1995,(4)

分析了目前利用流动形变、重力、地磁复测资料进行地震预测所存在的困难，探讨了综合利用三种手段追踪应力场及地下介质动态的途径，提出了断层综合监测布点的原则，并介绍了依此原则所建的京西试验场的基本情况。  相似文献   

Secular resonances in the asteroid belt: Theoretical perturbation approach and the problem of their location     

Alessandro Morbmelli  Jacques Henrard 《Celestial Mechanics and Dynamical Astronomy》1991,51(2):131-167

In this paper a theoretical perturbation approach to the problem of the dynamics in secular resonance is exposed. This approach avoids any expansion of the main term of the Hamiltonian (linear term in the masses) with respect to the eccentricity or the inclination of the asteroid, in order to achieve results valid for any value of these variables. Moreover suitable action-angle variables are introduced to take properly into account the dynamics related to the motion of the argument of perihelion of the asteroid, which is relevant at high inclination. A class of secular resonances wider than that usually considered is found. An explicit computation of the location of the main secular resonances, estimating also the contribution of the quadratic term in the masses by means of classical series expansion, is reported in the last sections. The accuracy of computations obtained by series expansion is discussed in the paper.  相似文献   

On the determination of meridional flow on the Sun by the method of tracers     

S. V. Olemskoy  L. L. Kitchatinov 《Astronomy Letters》2005,31(10):706-712

The standard methods for determining the meridional flow on the Sun from the motions of tracers are shown to give an error related to the latitudinal nonuniformity of the tracer distribution. We suggest a simple method for eliminating this error. Using this method to determine the meridional circulation from the motions of sunspots brings the result into agreement with helioseismological data on the meridional flow. The discussed effects can be important for observations of meridional flows on stars.  相似文献   

On one special case of parametric resonance in problems of celestial mechanics     

A. P. Markeev 《Astronomy Letters》2005,31(5):350-356

We consider a periodic (in time) linear Hamiltonian system that depends on a small parameter. At a zero value of this parameter, the matrix of the system is constant, has two identical pairs of purely imaginary roots, and is not reducible to diagonal form. Therefore, the unperturbed system is unstable. We propose an algorithm for determining the boundaries of the instability regions for the system at nonzero values of the small parameter. This algorithm was used to analyze the stability of triangular libration points in the elliptical restricted three-body problem and in the stability problem in one special case of stationary rotation of a satellite relative to the center of mass.  相似文献   

Fourier parameters and moments of polarization profiles of magnetically active lines. Fourier vector magnetograph     

B. Ioshpa  V. Obridko  I. Kozhevatov 《Solar physics》1996,164(1-2):373-380

A new method is proposed to determine all components of the solar magnetic fields using the cumulants of the profile of a magnetic sensitive line. The method is based on polarization measurements in a number of points of the line profile and subsequent calculation of the amplitudes and phases of its two first Fourier-harmonics.  相似文献   

太阳物理学中的分形和混沌   总被引：1，自引：0，他引：1  

环遵祥  吴铭蟾 《天文学进展》1996,14(4):286-296

对非线性科学的两个重要分支；分形和混沌在太阳物理学中的应用情况作了综述信要内容包括；太阳活动混沌性的揭示；对太阳活动混沌性的可能解释－太阳非线性发电机理论；一些太阳现象的分形描述；耀斑的自组织临界行为研究，最后给出了作者对这一领域工作前景的展望。  相似文献