Résumés

Sans résumé     

用边界元法计算点源二维地电体ρs与ηs

边界元法是一种新的微分方程数值解法.本文讨论了用该法求解点电源场中任意起伏地形下二维地电体位场问题的方法原理和数值处理技术,并给出了不同的地电体视电阻率与视极化率的计算结果相应用实例. 结果表明:边界元法是求解电法勘探边值问题和资料处理的一种经济有效的数值计算方法.     

A geologist’s shining path

Chronicle

A geologist’s shining path     

Der bau der südamerikanischen Kordillere

Ohne Zusammenfassung     

Genesis of volatile components at Saturn’s regular satellites. Origin of Titan’s atmosphere

Jupiter’s and Saturn’s regular satellites, which posses much ice, are currently thought to have been formed during the early evolution of the Solar System in circumplanetary protosatellite disks. Two of Saturn’s regular satellites—Titan and Enceladus—were experimentally proved to contain, along with water, other volatile components: molecular nitrogen, and methane (which are the major components of Titan’s atmosphere) and various nitrogen and carbon compounds in water plumes of Enceladus. The protomaterial of these rocky–icy satellites was formed in the outer regions of the gas–dust circumsolar nebula, and its closest analogue currently accessible to study is cometary material. The paper presents a review of experimental data on the chemical and isotopic composition of cometary material as possible sources of volatile components on Titan and Enceladus and model evaluations of temperatures in the circumsolar gas–dust protoplanetary disk and Jupiter’s and Saturn’s protosatellite disks during various evolutionary episodes of the solar system. The P–T parameters of the origin of the protomaterial of Jupiter’s and Saturn’s regular satellites were proved to have been remarkably different, and hence, the material of Europa, a Jupiter’s regular satellite, cannot contain any volatile components other than water, in contrast to Titan and Enceladus. This conclusion is supported by experimental data. Cometary material is likely genetically related to the material of Saturn’s regular satellites Titan and Enceladus. The paper presents results of thermodynamic simulation of the evolution of the chemical and phase composition of Saturn’s satellites and suggests a model for the origin of Titan’s nitrogen–methane atmosphere.     

激电测深法在找水中ρs和ηs曲线何者为主？

阐明了在松散层中找水，应以ρｓ曲线为主进行分析；在碳酸盐类岩层中找水，则ηｓ曲线比较关键，但又不能忽视对ρｓ曲线的分析。     

Time-lag effects in Parker’s dynamo

The effects of a time lag in the magnetic quenching of the α effect is considered for an oscillating magnetic field in a Parker dynamo. The hypothesis of a parametric resonance in the system is justified, a modification of the solution is found, and the appearance of processes with periods much longer than the fundamental oscillation period is demonstrated.