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991.
992.
In this paper, the process of source dynamics of the Jingtai earthquake (M=6.2) is studied on the basis of both earth resistivity changes before the event and the spatial directivity of single-observatory
magnitude measurements of the seismic network of China. The following conclusions are obtained: the NW-SE directional tension
stress (or the one about in the direction) inside the source region was enhanced during the short period from three to five
months before the event, and done still further about in twenty odd days before the event, so that it finally leads the fault
in about the EW strike to produce dislocation in NWW-SEE direction. Finally, this dislocation pattern caused the strong ground
vibration to be received at the seismic observatories which were located in the NWW and SEE directions of the epicenter, while
the weak vibration to be received at the ones in NE and south directions of the epicenter. At last, understandings on the
imminent earthquake prediction through earth resistivity method are set forth.
This subject is supported by the Science Foundation of Gansu Province and the Youth Foundation of the Earthquake Research
Institute of Lanzhou, SSB. 相似文献
993.
In this paper, the process of source dynamics of the Jingtai earthquake (M=6.2) is studied on the basis of both earth resistivity changes before the event and the spatial directivity of single-observatory magnitude measurements of the seismic network of China. The following conclusions are obtained: the NW-SE directional tension stress (or the one about in the direction) inside the source region was enhanced during the short period from three to five months before the event, and done still further about in twenty odd days before the event, so that it finally leads the fault in about the EW strike to produce dislocation in NWW-SEE direction. Finally, this dislocation pattern caused the strong ground vibration to be received at the seismic observatories which were located in the NWW and SEE directions of the epicenter, while the weak vibration to be received at the ones in NE and south directions of the epicenter. At last, understandings on the imminent earthquake prediction through earth resistivity method are set forth. 相似文献
994.
995.
996.
997.
Du Andao He Hongliao Yin Ningwan Zou Xiaoqiu Sun Yali Sun Dezhong Chen Shaozhen Qu Wenjun 《《地质学报》英文版》1995,8(2):171-181
Abstract This study deals with the first application of the isotope dilution-inductively coupled plasma mass spectrometry in the rhenium-osmium geochronometry in China. The chemical separation procedure included decomposition of samples by means of alkali fusion, extraction of rhenium by acetone and extraction of osmium by distillation. The recovery of both elements in the entire process was more than 90% . The blanks of analyses were 0.07 ng for rhenium and 0.01 ng for <sup>187</sup>Os. The mineralization ages of molybdenites from four molybdenum deposits in China were determined by using this method, with a precision (2σ) of about ±3% . These results agree satisfactorily with their geological backgrounds. The Re-Os method can directly determine ages of metal deposits and reflect the true ages more reliably than other dating methods that only determine the ages of country rocks from which mineralization ages are inferred. As many hydrothermal sulphide deposits usually contain molybdenites, this method has bright prospects of wide application. 相似文献
998.
999.
戈壁风沙流若干特征研究 总被引:15,自引:10,他引:15
本文从理论推导入手,阐述了戈壁风沙流中沙粒起跃角度、跃移高度和风沙流结构、强度、能量分布状况等特征,指出与流沙地表风沙流的显著差异,并得到风洞实验验证。 相似文献
1000.
盐湖卤水的蒸发结晶过程 总被引:3,自引:4,他引:3
本文从实验和理论相结合的角度上,总结了三十多年我国数十个盐湖等温蒸发和天然蒸发研究结果和研究经验,概括了三种类型盐湖卤水蒸发结晶的规律性,推荐了卤水蒸发结晶的相化学基础数据.对氯化物型卤水,由于介稳程度小,可采用Zdanovskii推荐的四元体系Na+、K+、Mg(2+)∥Cl-—H2O平衡相图进行太阳池工艺计算;对于硫酸盐型卤水,宜用金作美五元体系Na+、K+、Mg(2+)∥Cl-、SO,-H2O介稳相图,而不是Van’tHoff平衡相图;对于后期,锂盐高度浓缩,宜用我们的四元体系Li+、Mg(2+)∥Cl-、SO-H2O介稳相因;对于碳酸盐型盐湖卤水,可用我们的五元体系Na+、K+∥Cl-、CO、SO-H2O介稳相图作为相化学基础,而不是Teeple平衡相图.从相平衡热力学角度上,实现了对卤水蒸发结晶过程的理论描述、计算和预测.其中对一里坪、达布逊、东台吉乃尔、西台吉乃尔等盐湖卤水的研究结果尚属首次报道. 相似文献