The hypothetical chemical and spectroscopic activity of Germane in the atmosphere of Jupiter     

Raymond J. Corice Jr.Kenneth Fox 《Icarus》1972

It is suggested that in a reducing environment such as the Jovian atmosphere, GeH₄ may be spectroscopically active. Absorption features might be detectable in the 4.7μ window in the Jovian upper atmosphere.  相似文献   

Anorthite: thermal equation of state to high pressures     

Raymond Jeanloz  Thomas J. Ahrens 《Geophysical Journal International》1980,62(3):529-549

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Radar backscattering from a rough rotating triaxial ellipsoid with applications to the geodesy of small asteroids     

Raymond F. Jurgens 《Icarus》1982,49(1):97-108

Their measurements were based on the spectral properties of a rough rotating triaxial ellipsoid. This paper presents the theory by which theoretical spectra based on a backscattering model of the form cosⁿθ, or any reasonable backscattering model, can be computed. Some general properties of these spectra are demonstrated, and simple measurements of the apparent radar cross section, center frequency, and effective bandwidth as a function of time are shown to be useful in determining the sizes of the semi-major axes, the exponent n in the scattering model, the backscatter efficiency of the surface material, the rotation period, and the declination of the observer above or below the rotation equator. Some of these parameters are correlated, and multiple estimation may be difficult unless the observations span a period sufficiently long so as to present a wide range of declinations to the observer. However, the departure from a spherical shape aids in separating the scattering properties from the target dimensions and facilities the simultaneous estimation of all free parameters.  相似文献   

Book reviews     

E. M. Yates  Raymond M. Rice 《GeoJournal》1978,2(1):90-90

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An identification technique for evaluation of phenomenological coefficients in coupled flow in unsaturated soils     

Raymond N. Yong  Da-Ming Xu 《国际地质力学数值与分析法杂志》1988,12(3):283-299

To determine moisture movement and heat transfer through an unsaturated soil under temperature and volumetric water content gradients, it is necessary to have knowledge of phenomenological coefficients of the soil. However, in unsaturated flow, i.e. flow through unsaturated soil, these phenomenological coefficients are not constants, but vary with volumetric water content as well as temperature. In this paper, an identification technique is proposed for evaluation of the phenomenological coefficients. The phenomeno-logical coefficients are first assumed to be certain kinds of functions of volumetric water content and temperature. The choice of the functional forms is based on an understanding of the physical situation, and previous knowledge of water flow in the isothermal case. The constant parameters associated with the functional forms are evaluated through the use of the identification technique. Once these phenomenological coefficients are obtained as certain functions of the volumetric water content and the temperature for a specified soil, analysis of coupled moisture flow and heat transfer in the unsaturated soil can proceed.  相似文献   

High-resolution simulations of the final assembly of Earth-like planets I. Terrestrial accretion and dynamics     

Sean N. Raymond  Thomas Quinn  Jonathan I. Lunine 《Icarus》2006,183(2):265-282

The final stage in the formation of terrestrial planets consists of the accumulation of ∼1000-km “planetary embryos” and a swarm of billions of 1-10 km “planetesimals.” During this process, water-rich material is accreted by the terrestrial planets via impacts of water-rich bodies from beyond roughly 2.5 AU. We present results from five high-resolution dynamical simulations. These start from 1000-2000 embryos and planetesimals, roughly 5-10 times more particles than in previous simulations. Each simulation formed 2-4 terrestrial planets with masses between 0.4 and 2.6 Earth masses. The eccentricities of most planets were ∼0.05, lower than in previous simulations, but still higher than for Venus, Earth and Mars. Each planet accreted at least the Earth's current water budget. We demonstrate several new aspects of the accretion process: (1) The feeding zones of terrestrial planets change in time, widening and moving outward. Even in the presence of Jupiter, water-rich material from beyond 2.5 AU is not accreted for several millions of years. (2) Even in the absence of secular resonances, the asteroid belt is cleared of >99% of its original mass by self-scattering of bodies into resonances with Jupiter. (3) If planetary embryos form relatively slowly, then the formation of embryos in the asteroid belt may have been stunted by the presence of Jupiter. (4) Self-interacting planetesimals feel dynamical friction from other small bodies, which has important effects on the eccentricity evolution and outcome of a simulation.  相似文献   

地震监测设施与观测环境保护工作探讨   总被引：1，自引：1，他引：1  

哈辉 《高原地震》2001,13(4):27-33

在对地震监测设施及观测环境保护工作现状进行概述后，分析提出了加强地震监测设施及观测环境保护工作的措施和建议。  相似文献   

沙丘背风侧气流及其沉积类型与意义   总被引：6，自引：2，他引：6  

哈斯  王贵勇  董光荣 《沉积学报》2001,19(1):96-100,124

在腾格里沙漠东南缘对现代沙丘表面气流、沉积过程的野外观测结果表明,由于区域气流、沙丘形态及其相互作用等的不同使沙丘背风坡气流发生变化,在此发现三种背风坡次生气流 :分离流、附体未偏向流和附体偏向流。前者以弱的反向流为特征多发生在横向气流条件下坡度较陡的背风坡;后二者具有相对高的风速,其中附体流多发生在坡度缓和的背风坡,其方向在横向气流条件下保持原来的方向,而在斜向气流作用下发生偏转且其强度为原始风入射角的余弦函数。根据背风坡气流方向及强度,作者阐述了不同区域气流环境中沙丘背风坡沉积过程、层理类型及特征,探讨了交错层产状与区域气流方向之间的关系.  相似文献   

Waves and stationary patterns in the core and the interpretation of transition fields in geomagnetic polarity reversals     

Raymond Hide 《Surveys in Geophysics》1996,17(2):213-214

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Evaluation of coupled heat and moisture flow parameters in a bentonite-sand buffer material     

Raymond N. Yong  Abdel-Mohsen O. Mohamed 《Engineering Geology》1996,41(1-4):269-286

Several series of one-dimensional tests were used to study the nature of transient heat and moisture movements in a clay buffer under different imposed temperature gradients. The measured temperature and moisture profiles were used to calculate the diffusion parameters governing heat and moisture movement in the buffer material. The experimentally determined diffusion parameters are shown to be dependent on the moisture content and temperature. The diffusion parameters were calculated by using an identification technique, the root-time method, and an analytical technique.  相似文献