刚性桩与柔性桩复合地基共同作用研究现状     

胡仁众 《华南地质与矿产》2007,(2):62-65

刚性桩与柔性桩共同作用的复合地基是一项新的地基处理技术,是现在学术界和工程界研究的热点。本文通过对其特性、设计参数、理论研究和工程实践等各个方面进行了讨论,提出了自己的一些观点。  相似文献   

面向对象空间数据组织与管理的初步实现     

周东 张翔夏小强  王前卫罗小龙 刘少华 《东北测绘》2007,30(6):117-118,121

通过分析3种传统数据模型的特点，得出它们在管理地理复杂对象方面的局限性，从而引出了面向对象数据模型。本文利用面向对象数据模型中的各种操作，以基本地理对象为基础构建复杂地理对象，并且在VC＋＋6．0平台上实现了面向对象几何数据模型。  相似文献   

Adakitic magmas in the Ecuadorian Volcanic Front: Petrogenesis of the Iliniza Volcanic Complex (Ecuador)   总被引：1，自引：0，他引：1  

Silvana Hidalgo  Michel Monzier  Hervé Martin  Gilles Chazot  Jean-Philippe Eissen  Jo Cotten 《Journal of Volcanology and Geothermal Research》2007

The Iliniza Volcanic Complex (IVC) is a poorly known volcanic complex located 60 km SSW of Quito in the Western Cordillera of Ecuador. It comprises twin peaks, North Iliniza and South Iliniza, and two satellite domes, Pilongo and Tishigcuchi. The study of the IVC was undertaken in order to better constrain the role of adakitic magmas in the Ecuadorian arc evolution. The presence of volcanic rocks with an adakitic imprint or even pristine adakites in the Ecuadorian volcanic arc is known since the late 1990s. Adakitic magmas are produced by the partial melting of a basaltic source leaving a garnet rich residue. This process can be related to the melting of an overthickened crust or a subducting oceanic crust. For the last case a special geodynamic context is required, like the subduction of a young lithosphere or when the subduction angle is not very steep; both cases are possible in Ecuador. The products of the IVC, made up of medium-K basaltic andesites, andesites and dacites, have been divided in different geochemical series whose origin requires various interactions between the different magma sources involved in this subduction zone. North Iliniza is a classic calc-alkaline series that we interpret as resulting from the partial melting of the mantle wedge. For South Iliniza, a simple evolution with fractional crystallization of amphibole, plagioclase, clinopyroxene, magnetite, apatite and zircon from a parental magma, being itself the product of the mixing of 36% adakitic and 64% calc-alkaline magma, has been quantified. For the Santa Rosa rhyolites, a slab melting origin with little mantle interactions during the ascent of magmas has been established. The Pilongo series magma is the product of a moderate to high degree (26%) of partial melting of the subducting oceanic crust, which reached the surface without interaction with the mantle wedge. The Tishigcuchi series shows two stages of evolution: (1) metasomatism of the mantle wedge peridotite by slab melts, and (2) partial melting (10%) of this metasomatized source. Therefore, the relative ages of the edifices show a geochemical evolution from calc-alkaline to adakitic magmas, as is observed for several volcanoes of the Ecuadorian arc.  相似文献   

Seismic study on oceanic core complexes in the Parece Vela back-arc basin   总被引：1，自引：0，他引：1  

Yasuhiko  Ohara  Kyoko  Okino  Junzo  Kasahara 《Island Arc》2007,16(3):348-360

Abstract   In the present study the seismic structure of oceanic core complexes (OCC) in the Parece Vela Basin, Philippine Sea have been imaged. Together with recent work on the Atlantis Massif OCC on the Mid-Atlantic Ridge, including deep drilling, this work provides an unprecedented opportunity to advance our understanding of OCC internal structure. A continuous, strong and relatively smooth reflection that was ca 0.15 s (two way time) below the sea floor of an OCC in the Chaotic Terrain of the Parece Vela Basin was identified. This reflection, termed the D-reflector, is similar to that observed beneath Atlantis Massif. A faster P-wave velocity (>6 km/s) is observed very shallow beneath the Chaotic Terrain OCC, suggesting that the core of these OCC is dominantly gabbroic. The D-reflector might be common beneath OCC, owing to localized alteration along fractured zones within gabbro. We further observed a series of three detachment events in the Chaotic Terrain. The first and second detachments exhumed shallow basaltic crust to deeper gabbroic core, whereas the last one only exhumed shallow basaltic crust.  相似文献   

复杂土壤深井接地电阻的计算方法   总被引：1，自引：2，他引：1  

刘任翔  许伟彬 《气象研究与应用》2007,28(4):58-61

以一种较为简单可行的计算方法,对移动通信基站在复杂土壤环境下的深井接地进行了设计计算尝试,并通过对三水某新建移动通信基站接地工程前期设计与施工实测值的比较,验证了该设计计算方法的可行性。  相似文献   

Internal structure of Ustica volcanic complex (Italy) based on a 3D inversion of magnetic data   总被引：1，自引：0，他引：1  

Rosalba Napoli  Gilda Currenti  Ciro Del Negro 《Bulletin of Volcanology》2007,69(8):869-879

A ground magnetic study of Ustica Island was performed to provide new insights into subsurface tectonic and volcanic structures. The total-intensity anomaly field, obtained after a data-reduction procedure, shows the presence of a W–E-striking magnetic anomaly in the middle of the island and another two intense anomalies, which seem to continue offshore, in the southwestern and the northeastern sides, respectively. The detected anomalies were analyzed by a quadratic programming (QP) algorithm to obtain a 3D subsurface magnetization distribution. The volcano magnetization model reveals the presence of intensely magnetized volumes, interpreted as the feeding systems of the main eruptive centers of the island, which roughly follow the trend of the main regional structural lineaments. These findings highlight how regional tectonics has strongly affected the structural and magmatic evolution of the Ustica volcanic complex producing preferential ways for magma ascent.  相似文献   

Experimental estimate of a relation between sea wave energies and the Earth’s crust microdeformations     

Grigory I. Dolgikh  Stanislav G. Dolgikh  Sergei N. Kovalev  Vladimir V. Ovcharenko  Vladimir A. Chupin  Vyacheslav A. Shvets  Sergei V. Yakovenko 《Acta Geophysica》2007,55(4):607-618

The experimental data in the microseismic frequency range obtained using the seismo-acoustic-hydrophysical measurement complex are analyzed. The emphasis is put on estimating the ratio between the energy of surface sea wind waves in the area of the Japan Sea where the complex was located and the Earth’s crust microdeformations in this frequency range. The experimental evaluate obtained allow us to estimate the energy re-distribution at the hydrosphere-lithosphere boundary.  相似文献   

贵州南部一次突发性大暴雨的中尺度分析   总被引：9，自引：0，他引：9  

毛冬艳  钱传海  乔林  陈涛  吴秋霞 《南京气象学院学报》2007,30(5):601-609

利用地面加密观测资料、贵州自动站雨量资料、FY-2C卫星红外辐射亮度温度(tbb)资料等,对2006年6月12日夜间贵州南部突发性大暴雨过程进行了中尺度分析.结果表明:具有类似于MCC(Mesoscale Convective Complex)特征的中尺度对流云团的发生发展及其缓慢东移是造成此次大暴雨的直接原因.对流层中低层大量的水汽输送和对流有效位能的积累为大暴雨的形成提供了有利的环境条件,中高层弱冷空气入侵使偏南暖湿气流被迫抬升、地面中尺度低压和辐合线的形成是暴雨发生的可能触发机制.中尺度天气系统具有低层辐合、高层辐散的高、低空配置,暴雨区南、北两侧的正、反垂直环流构成了中尺度次级环流圈的垂直结构特征.  相似文献   

Energy distribution of a stringy charged black hole     

Ragab?M.?GadEmail author 《Astrophysics and Space Science》2005,295(4):459-462

The energy distribution associated with a stringy charged black hole is studied using Møller’s energy-momentum complex. Our result is reasonable and it differs from that known in literature using Einstein’s energy-momentum complex.  相似文献   

Petrogenesis and dating of the Kangding complex,Sichuan Province   总被引：18，自引：1，他引：17  

CHEN Yuelong  LUO Zhaohua  ZHAO Junxiang  LI Zhihong  ZHANG Hongfei & SONG Biao . Faculty of Earth Sciences  Natural Resources  China University of Geosciences  Beijing  China  . Faculty of Earth Sciences  China University of Geosciences  Wuhan  China  . Beijing SHRIMP Center  Institute of Geology  Chinese Academy of Geological Sciences  Beijing  China 《中国科学D辑(英文版)》2005,48(5):622-634

The Kangding group, also known as the Kangding complex, includes granulites, amphibolites, felsic gneisses and gneissic granites that are distributed along a belt from Kangding, Mianning to Panzhihua, in Sichuan Province. The complex has long been thought to represent the crystalline basement of the Yangtze block. On the basis of U-Pb and Pb-Pb whole rock ages[1,2] , and of similarities in metamorphic fa-cies and association of metamorphic rocks with typical Archean high grade terrains, t…  相似文献