排序方式: 共有36条查询结果,搜索用时 15 毫秒
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给出了将构造图表示的地质模型向块体模型转化的曲面切割计算流程。用Delaunay三角形、约束Delaunay三角形和投影等,解决了曲面切割所遇到的交线求取、交线插入、交线三角形的搜索和沿交线断开等方法问题,并给出了实际模型的计算实例。 相似文献
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洪湖沉积物柱芯有机氯农药高分辨率沉积记录 总被引:10,自引:4,他引:6
测定了洪湖沉积物柱芯样品中有机氯农药(OCPs)的质量分数,探讨了有机氯农药的垂直分布特征,结合210Pb定年研究该地区有机氯农药的污染历史。研究结果表明,19种有机氯农药均有检出,不同组分质量分数差异较大,总有机氯农药质量分数范围为1.44~345.95 ng/g(干重)。从20世纪60年代开始,洪湖沉积物中总有机氯农药质量分数呈上升趋势,70年代达到最高峰,并且近年来湖区可能还有部分新的有机氯农药污染物的输入,其来源可能与周边人类活动有关。 相似文献
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Introduction
The Tanlu fault zone lies in the eastern China, which is an important huge active fault with a long history. It has experienced a complex generation and evolution process and affects significantly the regional structure, paleogeography, magma activity, minerogenesis and earthquake activity in the area. With a length of 2 400 km, the fault zone consists of 2-4 or more parallel faults of 10-40 km in width, cutting through different geotectonic elements in the eastern China (FANG et al, 1986). On July 25 in 1668, an extraordinarily large earthquake of M=8.5 occurred on the Changyi-Dadian fault (F1) that is an embranchment of Tanlu fault zone, resulting in a surface rupture with a total length of 130 km (LI et al, 1994; CHAO et al, 1995). The paleoseismic study reveals that 3 events with a magnitude equal to 8 occurred on the Changyi-Dadian fault. The recent event occurred 3 500 a ago and the reoccurrence interval is about 3 500 a (LIN and GAO, 1987). During the Tancheng earthquake (on July 25, 1668), the Anqiu-Juxian fault was not ruptured, which was a Late Pleistocene active fault (ZHENG et al, 1988; GAO et al, 1988; CHAO et al, 1994) and was doubted as the seismogenic fault of the M=7.0 Anqiu earthquake occurred in 70 BC by certain geologists (CHAO et al, 1994). 相似文献