排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
在室内的岩石破裂实验中,曾多次观测到波速的各向异性。托切尔(D,Tocher)的结果表明,平行压力方向波速的增加比垂直压力方向快得多。在某些情形下,差别大约超过10%。1973年古普塔(I.N.Gupta)的实验认为P波速度下降的最大值发生在最小压力轴方向上。1971年努尔(A.Nur)从理论上探讨了含裂缝的岩石中速度的各向异性问 相似文献
2.
3.
This paper proposes that the upper limit of intermediate-term prediction should be extended to about 20 years from several years, and that intermediate-term prediction should be divided into two stages, early-intermediate-term stage (>2-3 years) and late-intermediate stage. The seismicities in both stages are closely related and difficultly distinguished. The earthquake episode, which embodies the up and down of a group of strong earthquakes in about 20 years, is the main object of early-intermediate prediction. The concentrating process of small quakes along some belts and from far-field to near-field 2-3 years before strong earthquake, accompanied by several anomolies in geophysical and geological fields during the process, is the main object of late-intermediate prediction. Some precursors before Nine Strong Earthquakes (Ms≥7) during 1966-1976 are summarily introduced in the paper. Finally, four models of multi-(stress concetration) points, shunting visco-elastic elements, weakening of source inclus 相似文献
4.
5.
1