碳酸岩Sr、Nd、Pb 同位素地球化学研究评述

碳酸岩是出露相对较少的幔源岩石，其中Sr与Nd是研究地幔物质组成的主要对象之一。本文统计了世界上主要碳酸岩的锶、钕、铅同位素组成特征；研究显示，碳酸岩源区主要是洋岛玄武岩高U／Pb的HIMU端员和富集端员(EM1或EM2)的混合作用；此外大部分碳酸岩的锶、钕同位素落在大洋玄武岩范围内；这些均表明其成因与地慢柱有密切联系。碳酸岩及与之共生的硅酸岩的同源或独立源区模式部很难充分解释两者同位素组成特征，逭反映碳酸岩的演化模式涉及更复杂的过程。可能是俯冲作用使碳酸岩源区经历不同时间和程度的富集、亏损过程导致地幔源区成分不均一。     

复合地基沉降计算的复合本构有限元法适应性研究

复合本构有限元法是一种新型的复合地基沉降数值计算方法.采用复合本构有限元和传统三维有限元两种计算模型,通过不同桩土模量比、置换率和桩长条件下复合地基沉降计算结果的比较,对复合本构有限元法的适应性进行了探讨.     

Continental crustal growth and the supercontinental cycle: evidence from the Central Asian Orogenic Belt

Studies of supercontinental cycle are mainly concentrated on the assembly, breakup and dispersal of supercontinents, and studies of continental crustal growth largely on the growth and loss (recycling) of the crust. These two problems have long been studied separately from each other. The Paleozoic–Mesozoic granites in the Central Asian Orogenic Belt have commonly positive Nd values, implying large-scale continental crustal growth in the Phanerozoic. They coincided temporally and spatially with the Phanerozoic Pangea supercontinental cycle, and overlapped in space with the P-wave high-V anomalies and calculated positions of subducted slabs for the last 180 Ma, all this suggests that the Phanerozoic Laurasia supercontinental assembly was accompanied by large-scale continental crustal growth in central Asia. Based on these observations, this paper proposes that there may be close and original correlations between a supercontinental cycle, continental crustal growth and catastrophic slab avalanches in the mantle. In this model we suggest that rapid continental crustal growth occurred during supercontinent assembly, whereas during supercontinental breakup and dispersal new additions of the crust were balanced by losses, resulting in a steady state system. Supercontinental cycle and continental crustal growth are both governed by changing patterns of mantle convection.     

温州世贸中心大厦超深大直径钻孔灌注桩施工技术

介绍了超深大直径钻孔灌注桩在温州世贸中心大厦桩基工程中的应用情况，对其施工中出现的主要问题进行了分析和处理，并提出了解决措施。     

Progress in sandy desertification research of China

Desertification is one of the most serious environmental and socio-economic problems facing the world today. Because the rapid expansion of desertification has resulted in serious environmental deterioration, economic loss, locally unsteadiness political situation and social upheaval, it has become a hot-spot issue of worldwide concern. During the late 1960s and early 1970s, as the catastrophic drought in the west Africa greatly accelerated the development of desertification, the desertificati…     

我国农村合作医疗的地区模式

农村合作医疗是我国农村主要的医疗保障形式。但是由于我国各地社会经济发展水平不平衡，中央政府的扶持政策也有所不同，合作医疗出现了多种不同的地区模式。高收入地区、中等收入地区及低收入地区的合作医疗在筹资方式、管理方式和补偿方式上都各有特点。     

一体化基础地形地籍数据库的设计思想

结合某地市级一体化基础地形地籍建设工程，主要介绍了一体化基础地形籍数据库的总体设计思想．对几个值得特别注意的关键技术问题进行了探讨，并给出了基本解决方法。     

基于三角网的"种子法"多边形生成

将传统上广泛使用的“种子法”和“矢量求交法”的思想相结合 ,提出了一种基于约束Delaunay三角网结构的多边形生成算法。详细描述了该方法的基本思想 ,在实验基础上分析了算法的特点。     

The Application of ARGO Data to the Global Ocean Data Assimilation Operational System of NCC

1. Introduction It is well-known that the state of ocean plays very important role in the climate change. But there is a paucity of the ocean observation data. The data distri- bution in the space, time and different components is very inhomogeneous, even in some areas, there are no any observation data. Hence, it brings some diffcul- ties to the scientists to study many problems relevant to ocean. This situation has been being changed since ARGO (Array for Real-time Geostrophic Oceanogra-…     

Nonlinear free thermal convection in a spherical shell:A variable viscosity model

Introduction The velocity field of surface plate motion can be split into a poloidal and a toroidal parts.At the Earth′s surface,the toroidal component is manifested by the existence of transform faults,and the poloidal component by the presence of convergence and divergence,i.e.spreading and subduc-tion zones.They have coupled each other and completely depicted the characteristics of plate tec-tonic motions.The mechanism of poloidal field has been studied fairly clearly which is related to …