Analysis on Depth Distribution and Precursor Mechanism of Small and Moderate Earthquakes     

Wang Jian 《中国地震研究》2001,15(4):406-411

ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｓｅａｒｃｈｏｎｅａｒｔｈｑｕａｋｅｆｏｃｕｓｄｅｐｔｈｄｉｓｔｒｉｂｕｔｉｏｎａｎｄｉｔｓｐｈｙｓｉｃａｌｂａｃｋｇｒｏｕｎｄｉｓｏｎｅｏｆｍｏｓｔａｔ ｔｅｎｔｉｖｅｐｒｏｂｌｅｍｓ.Ｐｒｏｆ.ＦｕＺｈｅｎｇｘｉａｎｇ (1 996)ｒｅｓｅａｒｃｈｅｄｔｈｅｒｅｌａｔｉｏｎｓｂｅｔｗｅｅｎｆｏｃｕｓｄｅｐｔｈｄｉｓｔｒｉｂｕ ｔｉｏｎｏｆａｆｔｅｒｓｈｏｃｋｓ ,ｃｒｕｓｔａｌｖｅｌｏｃｉｔｙｌａｙｅｒｓａｎｄｓｕｒｆａｃｅｔｈｅｒｍａｌｆｌｏｗ .Ｒｅｓｅａｒｃｈｏｎｆｏｃｕ…  相似文献   

Two-dimensional geostatistical modeling and prediction of the fracture system in the Albala Granitic Pluton, SW Iberian Massif, Spain     

J. Escuder Viruete  R. Carbonell  M. J. Jurado  D. Martí  A. Prez-Estaún 《Journal of Structural Geology》2001,23(12)

We use a fracture index distribution method of geostatistical modelling and prediction to characterize quantitatively the fracture system in two-dimensions (2D) in the Mina Ratones area, located in the Albalá Granitic Pluton (SW Iberian Massif). The fracture index (FI) is a quantitative estimate of the fracture density in discrete domains. To validate the results of geostatistical modeling a detailed structural map of the area was also made on a scale of 1:1000. The resulting grids, expressed as pixel-maps, describe the continuous value of the FI in 2D for the whole Mina Ratones area. Based on the modelled distribution of the FI and their correlation with mapped faults, we distinguish two structural domains in the studied area: elongated bands of fracture zones with high FI values and romboidal blocks located between them with low FI values. The separation between both domains is gradual. Though a threshold value of the FI that separate both structural domains is not clearly defined, the fracture zones generally present FI>1 and the individualized blocks FI<0.50. As a consequence, the obtained grid of the FI permits the quantitative structural classification of the granitic massif in 2D and understanding fault zone architecture in the Mina Ratones area.  相似文献   

Electric conductivity of Fe2SiO4–Fe3O4 spinel solid solutions     

T. Yamanaka  H. Shimazu  K. Ota 《Physics and Chemistry of Minerals》2001,28(2):110-118

 The spinel solid solution was found to exist in the whole range between Fe₃O₄ and γ-Fe₂SiO₄ at over 10 GPa. The resistivity of Fe_{3− x} Si _x O₄ (0.0<x<0.288) was measured in the temperature range of 80∼300 K by the AC impedance method. Electron hopping between Fe³⁺ and Fe²⁺ in the octahedral site of iron-rich phases gives a large electric conductivity at room temperature. The activation energy of the electron hopping becomes larger with increasing γ-Fe₂SiO₄ component. A nonlinear change in electric conductivity is not simply caused by the statistical probability of Fe³⁺–Fe²⁺ electron hopping with increasing the total Si content. This is probably because a large number of Si⁴⁺ ions occupies the octahedral site and the adjacent Fe²⁺ keeping the local electric neutrality around Si⁴⁺ makes a cluster, which generates a local deformation by Si substitution. The temperature dependence of the conductivity of solid solutions indicates the Verwey transition temperature, which decreases from 124(±2) K at x=0 (Fe₃O₄) to 102(±5) K at x=0.288, and the electric conductivity gap at the transition temperature decreases with Si⁴⁺ substitution. Received: 15 March 2000 / Accepted: 4 September 2000  相似文献   

Electronic structure and electric field gradient calculations of Al2SiO5 polymorphs     

M. Iglesias  K. Schwarz  P. Blaha  D. Baldomir 《Physics and Chemistry of Minerals》2001,28(1):67-75

 The electronic structure of the three polymorphs of Al₂SiO₅, andalusite, sillimanite, and kyanite, is studied by linearized-augmented-plane-wave (LAPW) calculations using the WIEN code. Total energy calculations verify, in agreement with recent pseudopotential calculations, that andalusite is the most stable phase, followed by sillimanite and kyanite.We determine the electronic charge density distribution and find strong polarizations on all oxygen ions. We identify different polarizations due to Al or Si neighbors which depend on their respective distances to the oxygen atom. The chemical bonding is not purely ionic in nature but has important covalent contributions. Electric field gradients (EFGs) at all sites are calculated and agree well (within 10%) with available experimental data on Al. We identify the origin of the EFGs and demonstrate its relation to the nearest-neighbor coordination and the resulting anisotropy of the electronic charge distribution. Received: 22 March 2000 / Accepted: 3 August 2000  相似文献   

数字式智能化锚索预应力传感器的研究与设计   总被引：4，自引：0，他引：4       下载免费PDF全文

胡时友王全成  姜昭群 《探矿工程》2001,(2):30-33

预应力传感器是锚固工程，预应力混凝土工程，预应力桥梁工程等领域进行监测，研究与试验必不可少的测量用传感器，在分析预应力传感器[研究现状的基础上，详细了介绍了数字式智能化锚索预应力传感器的工作原理，结论设计，计量检定结果，主要特点和应用情况。  相似文献   

赤道印度洋-太平洋地区海气系统的齿轮式耦合和ENSO事件 II.数值模拟   总被引：14，自引：2，他引：14  

孟文  吴国雄 《大气科学》2000,24(1):15-25

首先应用IAP/LASG GOALS气候模式的多年积分的结果，对赤道中西太平洋和印度洋 的SST和纬向风场进行分析，发现在模式中也同样存在与观测资料分析结果相似的“印太齿 轮式耦合”。基于此，设计了赤道太平洋和印度洋海域纬向风应力异常的4组敏感性试验， 去研究太平洋和印度洋海气相互作用的联系。结果表明，在太平洋或印度洋上的大气异常 信号通过印-太齿轮组合（GIP）作为桥梁（atmospheric bridge），影响到另一地的海气 相互作用，从而将太平洋上的ENSO类年际变率信号与印度洋环流和亚洲季风纬向分量的变 化联系起来。  相似文献   

福建龙卷风的活动特点   总被引：11，自引：1，他引：11  

鹿世瑾 《气象》1996,22(7):36-39

分析福建千余年２５次的龙卷风记载，得出如下几点认识：（１）福建的龙卷均在春夏两季，且几率相近；１９４９年以来的１２次龙卷有１１次出现于１３－１８时（占９２％），另一次是上午９时（占８％）。空间分布为：沿海地区有２０次，占８０％，内陆５次，占２０％，且有多发挥地段，（２）龙卷风多出现于低压，高温，高湿点附近，天空以积雨云占多数，地面多有强风相伴，（３）福建１２次龙卷风的诱发系统为：台风（６次，均在７  相似文献   

雨滴尺度谱谱参数和形状因子的分析     

周文贤  陈金荣  齐久成 《气象》1996,22(4):13-16

作者计算了３次降不过程的雨滴尺度谱参数，并进行Ｍ－Ｐ分布拟合和Г分布拟合。同时还计算了雨滴谱形状因子Ｓ（Ｚ，Ｒ），分析了形状因子与雨强之间的关系。  相似文献   

齿轮弯曲强度的有限元分析法   总被引：1，自引：0，他引：1  

许贤泽 《测绘信息与工程》1996,(4)

论述了齿轮弯曲强度的有限元分析方法，同传统的方法相比能准确地获得齿轮的真实应力场，为齿轮强度计算提供可靠的依据。  相似文献   

西沙群岛大气中海盐粒子的分布特征   总被引：9，自引：1，他引：9  

吴兑  游积平  关越坚 《热带气象学报》1996,12(2):122-129

分析了在西沙永兴岛观测的Ｃｌ＾－海盐核资料，主要结果有：（１）东北季风期干直径大于２μｍ的Ｃｌ＾－核平均浓度８７８个／Ｌ，平均含盐量１０５．４μｇ／ｍ＾３，其中干直径大于４μｍ的特大核平均为１９０个／Ｌ，最大间观测到干直径５７μｍ的Ｃｌ＾－粒子，均较该地在１９８７年５月西南季风盛行期的观测值高。谱型呈准单调下降的幂函数递减谱。（２）随距海面高度增加海盐粒子浓度与含盐量均有所减小。（３）Ｃｌ＾－粒子  相似文献