排序方式: 共有144条查询结果,搜索用时 15 毫秒
51.
Based on the 3-D Earth model, the common convert points-phase weighted stacks (CCP-PWS) migration method is used to image the upper mantle discontinuities beneath Northeast China (longitude 120°―132°; latitude 38°―40°) with 802 observed receiver functions. Teleseismic records are obtained from 4 stations belonging to CCDSN and 19 stations belonging to PASSCAL. A low-velocity layer has been detected at the depth of 620 km. This low-velocity layer rises to 600 km in the east of the study region close to the subducted slab. We consider that this low-velocity layer might be the accumulated oceanic crustal material delaminated from the western Pacific subducted slab. Additionally, we detect the obvious depression of 660 km discontinuity which was attributed to the interaction between the upper mantle and subducted slab. The maximum depth of 660 km discontinuity approaches 700 km, and 660 km discontinuity splits into multiple discontinuities in the northeast of the study region. 相似文献
52.
53.
袁庄矿于1959年1月15日开丁兴建,同年12月30日简易投产。2010年矿井核定生产能力68万吨年,实际生产原煤67万吨。南北长6.5公里,东西宽1.0-2.5公里,面积10.7Km2。井田内分中央、二庄两大通风系统,由于风机的老化和供风能力达不要求。 相似文献
54.
56.
57.
58.
59.
考虑到环保等因素,营运目标是时速360公里 FASTECH 360是以实现日本新干线高速化为目标的试验电气列车。它将在世界上首次进行包括制动性能等可靠性项目在内、长时间以时速360公里行驶的行驶试验。试验即将开始。 相似文献
60.
一、种羊场现状
1、自然资源状况:
我们横山县种羊场地处县城西南65公里处的狄青塬上,距横靖公路10公里。海拔1447、5—1516、2米。总面积10957亩。现有草场面积9317亩。 相似文献