辽宁岫岩M_S5.9地震前应力积累的讨论     

吴晶  太龄雪  高原  石玉涛  焦明若 《地震》2009,29(3)

使用营口地震台记录的地震波形资料, 对1999年11月29日辽宁岫岩MS5.9地震前后进行剪切波分裂分析, 结果表明剪切波分裂参数在岫岩地震前后有明显的变化, 慢剪切波时间延迟在岫岩地震前约142天开始增加, 揭示了震前的应力积累过程. 应力积累的持续时间与震级的关系符合对数坐标下的直线拟合经验统计关系.  相似文献   

An atlas of Zeeman polarisation in the Stokes IQUV spectrum of β Coronae Borealis     

G. A. Wade  J. -F. Donati  J. D. Landstreet   《New Astronomy》2000,5(8):455-482

We present an atlas of the Zeeman spectral line polarisation throughout the visible spectrum of the cool F0p star β CrB based on MuSiCoS spectropolarimetry. Stokes I, V, Q and U spectra covering the full 4500–6600 Å MuSiCoS intermediate bandpass are shown at sufficient display resolution so as to be suitable for the identification of individual spectral features. This is foreseen as being useful, for example, in the planning of very high resolution spectropolarimetric studies of Ap star Zeeman signatures using high-dispersion instruments likely to have significantly smaller spectral bandwidth.  相似文献   

恒星干涉测量中光的偏振效应     

Li Zaixiong  Wang Zhengming 《时间频率学报》1995,(1)

恒星光学干涉仪中两光路的偏振特性是影响其干涉条纹对比度的主要因素之一．偏振效应包括由于反射产生的位相延迟和光的振动方向的旋转，并可能严重降低干涉条纹对比度．本文分析了偏抓效应的产生原因和对干涉仪的影响，给出了三种典型的干涉仪光路布置，这些布置具有最小的条纹对比度损失．  相似文献   

Polarimetric properties of the reflection nebula R Mon/NGC 2261     

Masafumi Matsumura  Munezo Seki 《Astrophysics and Space Science》1995,224(1-2):513-514

The linear polarization of the reflection nebula R Mon/NGC 2261 has been observed since November 1991 with a multi-channel polarimeter at Dodaira Observatory, one of the branches of the National Astronomical Observatory of Japan. Results of the observations are reported.  相似文献   

Determination of polarization of vacuum-ultraviolet radiation by fluorescence and probe-beam techniques     

V. Yu Backman  S. V. Bobashev  O. S. Vasyutinskii 《Solar physics》1996,164(1-2):397-401

Polarization analysis of vacuum ultraviolet (VUV) radiation, especially the analysis of elliptical polarization is of considerable scientific interest in many areas of physics including solar physics. Polarization measurements in the VUV region are much less developed than those in visible and infrared spectral regions. It is due to lack of efficient phase shifting elements and small reflection coefficients of polarizers for VUV radiation. We propose two techniques, to determine the arbitrary polarization of VUV radiation with photon energies in the range 10 – 100 eV, which seem to be more efficient and precise than the known techniques, especially to study the polarization of atomic or molecular spectral lines.  相似文献   

卢龙地区S波偏振与上地壳裂隙各向异性   总被引：36，自引：12，他引：36       下载免费PDF全文

姚陈  王培德 《地球物理学报》1992,35(3):305-315

由三分量数字地震仪组成的小孔径流动台网记录了1982年10月19日河北卢龙M_s=6.1级地震的部分余震.用质点运动图的方法对横波的偏振进行了分析。研究结果表明,在横波窗内的各观测点都存在横波的分裂现象.不同离源角和方位角快波偏振的水平投影都具有近NE40°方向的优势取向,与根据卢龙地震两组断层错动在各向同性介质中所辐射的横波的偏振方向不一致.这可以由传播介质中应力所导致裂隙的定向排列来解释.这一观测结果提供了卢龙地区脆性上地壳大范围膨胀各向异性（EDA）的证据,并表明这一地区直立平行排列裂隙取向和水平主压应力的方向为NE40°.  相似文献   

低纬Pi2地磁脉动的多台观测          下载免费PDF全文

杨少峰 《地球物理学报》1991,34(2):154-160

本文分析了1988年12月和1989年1月在长春、北京、兰州3个台站上观测的地磁脉动资料,研究了3个台站同时记录到的Pi2地磁脉动的频谱特征和偏振特性,进而对低纬Pi2地磁脉动的产生和传播机制做了理论研究.  相似文献   

Polarimetric study of solar flares   总被引：1，自引：0，他引：1  

E. Vogt  J. C. Hénoux 《Solar physics》1996,164(1-2):345-359

The theory of impact polarization is briefly reviewed. Spectropolarimetry provides a tool to derive the nature, the number flux, and the main characteristics of the angular velocity distribution function of energetic particles accelerated in solar flares. As an exemple of application of polarimetry the spatial and temporal characteristics of the linear polarization of the hydrogen H line observed in a solar flare is presented.  相似文献   

Polarized radiation diagnostics of magnetohydrodynamic models of the solar atmosphere     

O. Steiner  U. Grossmann-Doerth  M. Schüssler  M. Knölker 《Solar physics》1996,164(1-2):223-242

Solar magnetic elements and their dynamical interaction with the convective surface layers of the Sun are numerically simulated. Radiation transfer in the photosphere is taken into account. A simulation run over 18.5 minutes real time shows that the granular flow is capable of moving and bending a magnetic flux sheet (the magnetic element). At times it becomes inclined by up to 30° with respect to the vertical around the level ₅₀₀₀ = 1 and it moves horizontally with a maximal velocity of 4 km/s. Shock waves form outside and within the magnetic flux sheet. The latter cause a distinctive signature in a time series of synthetic Stokes V-profiles. Such shock events occur with a mean frequency of about 2.5 minutes. A time resolution of at least 10 seconds in Stokes V recordings is needed to reveal an individual shock event by observation.The National Center for Atmospheric Research is sponsored by the National Science Foundation  相似文献   

A complex diagnostic of solar prominences     

P. Heinzel  V. Bommier  J. C. Vial 《Solar physics》1996,164(1-2):211-222

We use the polarimetric and intensity measurements of H and HeI D₃ lines in solar prominences to derive the true geometrical thickness for several quiescent prominences. The electron densities, derived from the collisional depolarization in H by Bommier et al. (1994), are used to evaluate the thickness from the emission measure. The emission measure was obtained from the theoretical correlation with the H integrated intensity, according to Gouttebroze, Heinzel, and Vial (1993). Theoretical electron densities obtained by latter authors are also compared with those of Bommier et al. (1994) and we find a very good agreement between them. The prominence geometrical thickness exhibits a relatively large range of values from about 100 km up to a few 10⁴ km. The plasma densities vary by almost two orders of magnitude in the observed structures, but the total column mass in the direction perpendicular to the prominence sheet seems to be fairly constant for the set of prominences studied.  相似文献