南北构造带天水、武都强震区地壳和上地幔顶部结构   总被引：1，自引：0，他引：1  

赖晓玲  李松林  宋占龙  樊计昌  刘明军  何加勇 《地球科学》2009,34(4):651-657

利用两条相互垂直的高分辨地震折射/宽角反射剖面和相应的非纵观测的多个扇形剖面取得的人工地震资料, 研究天水和武都8级大震区的地壳和上地幔顶部结构和构造.二维剖面结果显示, 地壳沿垂向可分为上地壳和下地壳两大层.上地壳中部存在低速层, 层内介质速度比背景值低0.3~0.5km/s.莫霍面深度大约为46~48km.NE向的天水-武都剖面下地壳速度在横向上变化剧烈, NW向的成县-武山剖面, 在礼县以西, Moho面和C界面有被上涌物质改造过的迹象.三维速度成像显示, 在105°E附近, 从7至11km的深度范围内, 存在一条近NS向的断裂带, 在该带的两侧速度结构有明显的差异, 西侧为低速异常, 而东侧为高速异常, 这一近NS向的断裂带与二维剖面的下地壳深断裂在位置上很接近.该地区的几个8级大震均发生在105°E附近, 并且呈一近NS条带.   相似文献   

QUAD��������RAIM���ϼ��   总被引：2，自引：0，他引：2  

任锴  杨力  赵庆海 《大地测量与地球动力学》2009,29(5):125-128

??QUAD????????????????????????????????????????????÷???????????????????????λ???????????е?????÷????????????漰????????????ú????????????????????  相似文献   

水泥土桩复合地基桩土应力比的一种解析算法   总被引：19，自引：7，他引：19  

秦然  陈征宙  董平 《岩土力学》2001,22(1):96-98

选取常用的双曲线函数来表征单桩与地基土的荷载－沉降曲线，导出了一组确定桩土应力比的解析算式，分析了桩土应力比与总荷载的关系，并指出置换率和桩土极限强度对桩土应力比的影响，运用该组公式对两组实测数据进行理论拟合，证实能反映实际情况，对复合地基的设计有参考意义。  相似文献   

Geometric form of Haiyuan fault zone in the crustal interior and dynamics implications   总被引：2，自引：0，他引：2  

樊计昌  李松林  张先康  刘明军 《地震学报(英文版)》2004,17(Z1)

Introduction The deep faults in the crust have direct relation to the occurrence of earthquakes and the dis-tribution of active seismic zones, so the researches on the geometric form and physical parametersof deep crustal faults are always an important problem in seismology. The researches are not onlysignificant to knowledge the deep tectonic background of strong earthquake and seismogenicmechanism, but also play a very important role in earthquake hazard estimation and earthquakeprevent…  相似文献   

Study on relationship between deep and shallow structures along north boundary fault of Yanqing-Fanshan basin     

于贵华  徐锡伟  朱艾澜  马文涛  刁桂苓  张四昌  张先康  刘保金  孙振国 《地震学报(英文版)》2004,17(1):70-79

IntroductionTheYanqing-Huailaibasin,whichconsistsoftheYanqing-FanshanandHuailai-Zhuolusub-basins,ismainlycontrolledbythenorthboundaryfaultsofthesub-basins.AsabasictectonicunitattheintersectionofthenortheasternendoftheNNE-trendingShanxigrabensystemandtheNW-trendingZhangjiakou-Penglaifaultzone,ithaskepttheintensivetectonicactivityintheQuaternary(YANG,1982;XU,DENG,1988;XU,MA,1992;FANG,etal,1993;Pavlides,etal,1999).Overthepastdecade,manyresearchershaveconductedstudiesonthedetailedstr…  相似文献   

2-D P-wave velocity structure in the mideast segment of Zhangjiakou-Bohai tectonic zone: Anxin-Xianghe-Kuancheng DSS profile   总被引：2，自引：0，他引：2  

王夫运  张先康  陈颙  李丽  陈棋福  赵金仁  张建狮  刘宝峰 《地震学报(英文版)》2004,17(Z1)

Introduction The Capital-circle area is the center of politics, economy and culture of China, and manystrong earthquakes occurred here in history. The Zhangjiakou-Bohai tectonic zone located in thearea is an important active zone. In the period of 500 years between AD 1481~1981, 18 earth-quakes with magnitude more than 6 occurred in the area and 11 of them lay in this active tectoniczone. During 1992~2001, continuous GPS observation found sinistral relative movement betweenYanshan Mo…  相似文献   

广域差分参考站两种伪距平滑算法的再评估   总被引：4，自引：0，他引：4  

何海波郭海荣  李保利 《测绘学院学报》2005,22(3):157-159

广域差分GPS系统（WADGPS）参考站上，需要利用载波相位平滑伪距算法来减小多路径效应的影响。伪距平滑算法有Hatch滤波和加权Hatch滤波两种。文中基于我国WADGPS参考站的实际数据，对这两种平滑算法进行重新评估。实际数据显示，如果不能获得可靠的伪距观测值的方差，在抑制伪距中噪声的影响方面，Hatch滤波明显优于加权Hatch滤波。  相似文献   

THE OPERATION MODE OF “STORING THE CLEAR WATER AND DISCHARGING THE MUDDY FLOW” FOR RESERVOIRS BUILT ON HEAVILY SILT-LADEN RIVERS——A CASE STUDY OF THE SANMENXIA RESERVOIR     

WenxueLI YuanfengZHANG CuipingZHANG 《国际泥沙研究》2005,20(2):109-116

Observation of the operation of the Sanmenxia Reservoir on the Yellow River has led to the conclusion that to preserve a certain effective storage volume for reservoirs built on heavily silt-laden rivers is feasible if the reservoir is operated according to the principle known as“storing the clear water and discharging the muddy flow”. The relative stability of the bed elevation at the end of the backwater and the reservoir‘s erosion and deposition equilibrium depend on the compatibility of the pool level maintained in non-flood seasons with the conditions of flow and sediment load during flood seasons. Operating the reservoir to regulate the flood and sediment load during flood seasons can reduce the rate ofaggradation in the Lower Yellow River. The basic condition for applying the operation mode of “storing the clear water and discharging the muddy flow” is that a sufficient amount of water should be used for discharging sediment during flood seasons. Under the condition of extremely low flow years, reservoir sedimentation cannot be avoided even if this operation mode is adopted.  相似文献   

脊髓纵裂征一例     

黎海亮  裴树举 《CT理论与应用研究》1996,5(4):34-35

本文报道了一例脊髓纵裂征，并着重讨论了该病Ｘ线ＣＴ表现，其中脊髓中央的骨嵴是诊断该病的关键，通过Ｘ线ＣＴ检查对比认为ＣＴ是最理想的诊断依据  相似文献   

近景光束法自由网联合平差的实际精度     

张永生 《武汉大学学报(信息科学版)》1989,(2)

本文从理论上分析了近景摄影测量光束法自由网联合平差的特点,借助于该方法对卫星地面站Cassegrain通讯天线抛物反射面的实际摄影资料进行平差处理,取得了较好的点位精度。  相似文献