The Formation and Evolution of the Lujiang-Zongyang Volcano-Structural Depression in Anhui and Its Relation to Mineralization

The Lujiang-Zongyang volcano-structural depression resulted from the combined action of tectonism and volcanism. Its evolution progressed through five stages from 190 to 105 Ma B.P., during which nine types of metal and pyrite deposits were formed. These deposits show obvious regularities in the temporal-spatial distribution and have certain genetic relation, forming a minerogenetic series related to shoshonite within or around the volcano-structural depression on the basement that sank for a long period of time. This paper suggests a four-dimensional model of the formation and evolution of a typical volcano-structural depression and its related mineralizalion in a transition belt from the active margins to the inner part of a plate under alternating shear-compressive and shear-extensional stress conditions, but predominantly shear-extensional stress conditions.     

天然硅酸岩铷锶同位素稀释测定小交换柱化学制备方法研究

本篇报道用于铷锶同位素年代测量的小柱分析流程。方法是在我们1972年草酸淋洗流程的基础上建立的。同时参考W.康普斯敦教授1977年介绍的小交换柱铷锶化学流程。样品提取方式、交换柱分离条件和操作步骤,是根据自己的实验确定的。流程有自身的特点。     

Seismic response of torsionally coupled base isolated structures

An analytical study of the seismic response of typical base isolated structures mounted on rubber bearings is presented. Isolated buildings are liable to have closely spaced lower modes of vibration with small eccentricity between centres of mass and rigidity. The isolated structure is modelled as a rigid deck with lumped masses supported on axially inextensible elastomeric rubber bearings. This simplified system has three degrees of freedom (dof), two translations and one rotation in the horizontal plane. The Green's functions for the displacement response of the 3 dof system are derived for both undamped and damped cases with small and large eccentricities. The small eccentricity case is taken from a specific isolated building, while the large eccentricity case arises from the 5 per cent accidental eccentricity which is required by various seismic codes. An interaction equation for normalized displacements is established for an idealized flat velocity spectrum or hyperbolic acceleration spectrum. An isolated building on rubber bearings would have its fundamental period fall into this range of a design spectrum. Numerical results for the specific building subjected to the El Centro earthquake of 1940 are presented. Both the time history and the response spectrum modal superposition analysis were performed. In the response spectrum analysis, the Complete Quadratic Combination (CQC) showed superiority over the Square Root of the Sum of Squares (SRSS) in estimating maximum responses. It is concluded that the effect of torsional coupling on the transient response of base isolated structures is insignificant, due to the combined effect of the time lag between the maximum translational and torsional responses and the influence of damping in the isolation system which for elastomeric bearings can be as high as 8 to 10 per cent.     

多波束测量系统在长江潜坝工程中的应用

通过叙述多波束测量系统在长江水下工程中的应用实践和体会，说明多波束测量系统和单波束等常规测量仪器相比，具有测深点多、测量迅速快捷、全覆盖等优点。     

Distribution of Large Volume Image Data Using the Mixed Mode of Java Servlet and COM on Web

This paper reports some researches on distribution of large volume image data using techniques of the Mixed Mode of Java Servlet and COM on Web. The architecture and key technologies are discussed in detail. The web distribution system of image is implemented and the system is tested by the application instances. At last, the advantages and disadvantages for this web image distribution mode are analyzed.     

Object Extraction Based on Evolutionary Morphological Processing

This paper introduces a novel technique for object detection using genetic algorithms and morphological processing. The method employs a kind of object oriented structure element, which is derived by genetic algorithms. The population of morphological filters is iteratively evaluated according to a statistical performance index corresponding to object extraction ability, and evolves into an optimal structuring element using the evolution principles of genetic search. Experimental results of road extraction from high resolution satellite images are presented to illustrate the merit and feasibility of the proposed method.     

国际热核反应堆合作计划(ITER)中的地震问题

简要回顾了国际ITER项目厂址选择中地震问题的源起，介绍了ITER项目欧盟Cadarache和日本Rokkash。厂址涉及地震安全的主要问题，各方对厂址地震危险性的评价结果，以及中国对这两个厂址地震问题的认识与评价。     

网格技术及其在国土资源信息化中的应用探讨

本文介绍了网格技术、网格计算的应用前景,以及网格技术在国际和国内的进展,对 网格技术在耕地遥感专题影像处理、国土资源部门政务处理、国土资源数据中心建设 等方面的应用作了展望。最后提出了国土资源信息网格的建设设想和基本思路。     

土地利用更新调查监理工作方法

大型测绘项目引入监理机制,是近年来推行的一种测绘项目管理方法,是加强测绘行业监督管理的有效手段,将成为测绘工程中不可或缺的工作.在土地利用更新调查方面的监理工作亦是一项刚刚开展的工作.