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Recent years have been marked by progress in studying the structure of natural X-ray amorphous substances, anthraxolites included, by scanning electron and atomic power microscopy. Integration of the available data on molecular and supramolecular structure of higher anthraxolites from Karelia, Novaya Zemlya, and the Urals allowed elaboration of new classification criteria for solid bitumen, namely, degree of structure perfection and micromineral composition. This approach will help to eliminate disadvantages of traditional investigation of solid bitumen.  相似文献   
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I.HydrogeographicalCharacteristicsTheLancangMekongRiveroriginatesfromasmallglacierof0.4km2inareaatanelevationof5167minLasaigongmaMountain(alsocalledZhaicuoMountain)atnorthernfootofTanggulaMountainRangewithinZaduoCounty,YushuTibetanAutonomousPrefecture,Qing…  相似文献   
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The non-hydrostatic part of the second zonal harmonic term has been included in the Indian gravity anomaly. The interpretation of the potential, gravity and deflection of the vertical has been produced by a new method. The depth of the source is 580 km and the solution satisfies the temperature gradient of 1°K/km. The ratio Δ Vpp > 0 shows the thermal nature of the density distribution near 670 km.  相似文献   
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Introduction Europe's mountains cover nearly half of the continent's area (Price et al. 2004) and land cover varies significantly (European Commission 2004). In most massifs, except for Sicily, southern Greece, and the British Isles, forest cover is dominant. In northern Europe, grassland is proportionately more important, and much of the mountains of the British Isles is covered by moorland. In central and southern Europe, arable land is of far greater importance than grassland, with Med…  相似文献   
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Analytical models of the palaeomagnetic field have been constructed for a number of geological periods (Quaternary Neogene, Jurassic, Triassic, Permian and Permo-Carboniferous) by spherical harmonic analysis using the present-day world map as a basis and (for the earlier periods) using also a palaeogeographic reconstruction. The use of the palaeogeographic chart for the earlier periods simplifies the models, and its use appears to be valid. The low accuracy, small number and uneven distribution of palaeomagnetic data severely limit the conclusions which can be drawn from the analyses. Nevertheless the results for all periods indicate that throughout the past 300 million years the geomagnetic field has maintained its global structure, and has remained similar to the field of a dipole slightly shifted from the Earth's centre. It appears that there have not been any persistent systematic anomalies or variations in the Earth's magnetic field throughout that time, but rather that the field has been oscillating around a mean level not greatly different from that of the present epoch.  相似文献   
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I.InternationalRiversandtheLancangMekongRiverInternationalriversaredefinedastheriverswhichflowacrostwoortwomorecountries.Upt...  相似文献   
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中国大陆若干地震构造带的地震准周期丛集复发行为   总被引:8,自引:3,他引:5  
以青藏高原东南缘和东北缘若干地震构造带的历史地震活动资料为基本数据,通过地震复发间隔的计算,分类和统计检验等,研究了大陆板内地震的复发行为。认为:大陆板内地震既不是简单地准周期重复发生,也不是简单地丛集复发,而可能是一种准周期的丛集复发行为,即地震丛是准周期重复发生的,而在某一地震丛内,地震又是丛集复发的。存在两类地震复发间隔,即地震丛复发间隔和地震丛内的地震复发间隔,它们分别满足对数正态分布和指数分布。在进行大陆板内活动断裂地震危险性定量计算和评估时,不能简单地套用N.B.实进模型中给出的地震复发间隔概率密度函数或累积分布函数,而应该根据当前地震的活动水平,判断当前是属于丛内的活跃期还是丛间的平静期,据此分别选用地震丛内地震复发间隔分布函数或者地震丛复发问题隔分布函数,这样将大大提高活动断裂地震危险性计算和定量评估的水平。最后,简要探讨了大陆板内地震准周期丛集复发行为的可能物理机制。  相似文献   
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This paper is concerned with solving the problem of the nature of superhydrostatic flattening of the Earth. An unambiguous method for the interpretation of gravity anomaly has been devised.  相似文献   
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An improved interpretation of the largest anomalies of gravity field is presented herewith. The anomalous potential, gravity and deflection of the vertical have been used at a single point. The depth of the sources does not depend on the anomalous density and the form of the body. The interpretation is unique in the physical sense.  相似文献   
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