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11.
12.
Zdeněk Kopal 《Astrophysics and Space Science》1975,35(1):159-170
The aim of the present paper will be to extend the Fourier methods of analysis of the light curves of eclipsing binaries, outlined in our previous communication (Kopal, 1975) in connection with systems whose components would appear as uniformly bright discs, to systems whose components exhibit discs characterized by an arbitrary radially-symmetrical distribution of brightness —i.e., an arbitrary law of darkening towards the limb — be it linear or nonlinear.In Section 2 which follows a few brief introductory remarks, fundamental equations will be set up which govern the light changes arising from the mutual eclipses of limb-darkened stars — be such eclipses total, partial or annular; and Section 3 will contain a closed algebraic solution for the elements of the occulation eclipses terminating in total phase. Such a solution proves to be no more complicated than it turned out to be for uniformly bright discs in our previous paper; and calls for no special functions for the purpose — as will be put in proper perspective in the concluding Section 4.The cases of transit eclipses terminating in an annular phase, of partial eclipses of occulation or transit type, will be similarly dealt with by Fourier methods in the next paper of the present series. 相似文献
13.
A new method to determine semi-analytical solutions of one-dimensional contaminant transport problem with nonlinear sorption is described. This method is based on operator splitting approach where the convective transport is solved exactly and the diffusive transport by finite volume method. The exact solutions for all sorption isotherms of Freundlich and Langmuir type are presented for the case of piecewise constant initial profile and zero diffusion. Very precise numerical results for transport with small diffusion can be obtained even for larger time steps (e.g., when the Courant-Friedrichs-Lewy (CFL) condition failed). 相似文献
14.
Origin of a large breccia-vein system in the Sanerlin uranium deposit, southern China: a reinterpretation 总被引:1,自引:0,他引:1
The early Tertiary Sanerlin uranium deposit is located near the southwestern margin of the Chaling-Yongxing pull-apart basin defined by the Chaling-Yongxing and Chenxian-Linwu sinistral strike-slip faults in southern China. The uranium ores are hosted in 15 breccia-vein bodies, which are separately located in the cores of three secondary anticlines of the Upper Permian Dangchong Formation. Individual breccia-vein bodies are composed of fragments of silicified shale and sandstone from the Dangchong Formation, and quartz veinlets as cements. These fragments, together with quartz veins, form a mosaic texture. Hydrothermal pitchblende is the only commercial uranium mineral, mainly occurring as disseminated grains within quartz veins or coating fragments. Other metallic minerals include molybdenite, pyrite, chalcopyrite, galena, sphalerite, and red microcrystalline hematite. Fluid inclusions in quartz veins have homogenization temperatures ranging from 150 to 280 °C, and calculated salinity values between 5.6 and 13.4 wt% NaCl equivalent. Stable isotope analyses show that the mineralizing fluid was characterized by '18O values of -2.2 to +2.6 and 'DH2O values of -134 to -110. These analytical data demonstrate that hydrothermal fluids were mainly derived from formation waters (brines) of the Chaling-Yongxing basin. Fluid overpressuring was caused by an abnormal geothermal gradient and impermeable shales in the deposit area. The geometry, texture, and structure of the breccia-vein system, along with the fluid pressure estimates, suggest that hydraulic fracturing generated the mineralized breccia-vein system. Pitchblende and associated minerals were deposited when gaseous phases were released abruptly from the ore fluids due to the hydraulic fracturing. 相似文献
15.
试述福建顺昌南舟萤石矿地质特征 总被引:1,自引:0,他引:1
顺昌南舟萤石矿位于顺昌县埔上镇南舟村境内,1996年福建省区域地质调查队开展1:5万埔上幅区调时发现矿体,后开展普查工作表明该矿床规模大、交通方便,易于开采,现已投入开发利用。南舟萤石矿成矿地质特征在闽北丰富的萤石资源中具有一定代表性。 相似文献
16.
介绍试用1:33000比例尺航测资料,在JX-3解析测图仪上高倍放大航测1:1000比例尺地形图的成图方案和应采取的技术措施,运用 解析法模型绝对定向的原理,在全野布点时采用两种方案对照比较,进行理论和试验精度的分析,并给出试验结果。 相似文献
17.
本文介绍了用变频激电法寻找含金硫化物矿体 ,通过对视幅频效应 Fs,和交流视电阻率 ρsf的分析 ,取得了良好的地质效果 相似文献
18.
Nikola Stražičić 《GeoJournal》1996,38(4):445-453
Croatia, through its geographic position, is a Mediterranean/Adriatic and Central European/Danube state. As an Adriatic coastal state, it has a long maritime tradition, which is apparent in its well-developed shipping (2.4 million GT), the high-quality ship-building industry (among the top six in the world) and through its numerous sea ports, of which many were established in ancient times. The leading national port is Rijeka, which is at the same time an important transit port for Austria, Hungary, Slovakia and the Czech Republic.The exceptionally indented Croatian Adriatic coast with its attractive archipelagos and favorable climatic and oceanographic conditions in the coastal sea offers very advantageous conditions for comprehensive tourist utilization. This is particularly true of nautical tourism, which is complimented by a larger number of constructed and well-equipped yachting ports/marinas on the coast and islands. 相似文献
19.
临沧超大型锗矿床有机质与锗矿化的地球化学特征 总被引:10,自引:3,他引:10
临沧锗矿床是一产于第三系含煤岩系中的超大型矿床。矿床的最初锗源与盆地西缘的二云母花岗岩有关。主矿体产于下煤组沉积旋回的早期地层中,每一沉积阶段早期形成的褐煤和碳质泥岩中富含锗,最高含量达1470×10^-6。褐煤和碳质泥岩在矿化过程中平均富集了164-169倍。根据锗含量,褐煤和碳质泥岩可分为锗含量小于12×10^-6的低锗煤(泥岩)和大于90×10^-6的高锗煤(泥岩)。高锗煤中有机质富含氧官能 相似文献
20.
Dong Ruishu Xiang Hongfa Guo Shunmin Ran Hongliu and Fu ChanghongInstitute of Geology SSB Beijing China Institute of Geophysics SSB Beijing China 《中国地震研究》1997,(4)
There have been 12 possible locations of the earthquakes occurring in the South Yellow Sea since 1505.In this paper,the location of the earthquake that occurred in 1505 has been determined by the collection of more historical data of the influenced field,referring the isoseismal data of earthquakes with the epicentral intensityⅨ and combining geophysical field data with tectonic condition,due to its great influence on seismic safety assessment of some significant engineering. 相似文献