迎接"数字地球"的挑战

从地球科学发展战略的角度,分析了“数字地球”对中国的挑战以及“数字地球”本身所面临的挑战,论述了发展“中国数字地球”的必要性和可能性,提出了发展“中国数字地球”的战略措施     

我国农业气象业务体系的形成、完善和发展

该文总结了我国农业气象业务的发展。我国农业气象业务体系包括基础业务和业务系统两部分。40年来，农业气象业务体系的发展可分为两个阶段。第一阶段是50年代中期至60年代初业务发展的初级阶段，基础业务全面起步；第二阶段是80年代以来业务的发展阶段，基础业务和业务系统都得到发展，形成完善的业务体系。国家级农业气象业务在整个农业气象业务体系中起着十分重要的作用。     

国土资源信息核心元数据的研究

国土资源信息核心元数据是建立运行在国土资源数据交换网络上的国土资源信息目录的基础和重要组成部分，也是目前数字国土工程中实现国土资源数据共享的重要途径。分析了国内外地理信息元数据标准的发展状况，根据国土资源信息核心元数据确定的原则和描述要求，确定了国土资源信息核心元数据的主要内容，提出了以通用建模语言UML类图作为国土资源信息核心元数据的结构设计，用数据字典详细定义核心元数据的组成，以构成国土资源信息核心元数据的完整描述的设计方法。     

浙江天姆尖盆地中生代流纹岩的地球化学特征及成因探讨

浙江天姆尖盆地存在Ⅰ ,Ⅱ两类流纹岩 ,这两类流纹岩可能是由同一母岩浆经过结晶分异演化而来的 ,但是它们的各种性质及空间分布却有很大的区别     

Prediction of shock response for a quadrupod-mast using response spectrum analysis method

Mast is defined as Grade A equipment which is essential for the safety and continued combat capability of the ship. Therefore, in order to evaluate shock resistance under shock environments, this research adopts response spectrum analysis method in conjunction with a shock design spectrum inducted by US Navy after performing full-scale trials in establishing a shock response spectrum analysis, to be coordinated by using finite element’s discrete and calculating procedure. The cantilever beam was used to take the explosion shock as an example to verify the effectiveness of the proposed numerical procedure. Analysis results demonstrate a sufficient correlation. Also described herein in detail is the shock response of a quadrupod-mast. Analysis results provide a valuable reference for mast design.     

Shock responses of a surface ship subjected to noncontact underwater explosions

In combat operations, a warship can be subjected to air blast and underwater shock loading, which if detonated close to the ship can damage the vessel form a dished for hull plating or more serious holing of the hull. This investigation develops a procedure which couples the nonlinear finite element method with doubly asymptotic approximation method, and which considers the effects of transient dynamic, geometrical nonlinear, elastoplastic material behavior and fluid–structure interaction. This work addresses the problem of transient responses of a 2000-ton patrol-boat subjected to an underwater explosion. The KSF=0.8 is adopted to describe the shock severity. Additionally, the shock loading history along keel, the acceleration, velocity and displacement time histories are presented. Furthermore, the study elucidates the plastic zone spread phenomena and deformed diagram of the ship. Information on transient responses of the ship to underwater shock is useful in designing ship hulls so as to enhance their resistance to underwater shock damage.     

Modification of the Bouwer and Rice Method to a Cutoff Wall with a Filter Cake

The Bouwer and Rice method is a line-fitting method used to estimate the hydraulic conductivity of an aquifer by means of a slug test. When considering a relatively impermeable layer, called a filter cake, which may form at the interface between a cutoff wall and the natural soil formation, the assumptions of the Bouwer and Rice method are violated. A modification of the Bouwer and Rice method is proposed that incorporates the concept of a flow net, whereby the geometry of the cutoff wall and filter cake is effectively considered in estimating the hydraulic conductivity of a vertical cutoff wall.     

Number and volume raindrop size distributions in Taiwan

Knowledge of rainfall characteristics is very important for the accurate estimation of rainfall kinetic energy and prediction of soil erosion. In this study, a reliable and efficient data collection and analysis system was developed to analyse the natural raindrop data collected in subtropical Taiwan. Both raindrop size distributions by number and volume were carefully analysed. The seasonal variations of the rainfall erosivity factor R, which is an index of the erosive potential of rainfall and a function of rainfall kinetic energy, was also discussed. An isoerodent map of Taiwan was also developed based on the rainfall data recorded by 158 automated rainfall‐measuring stations within 26 years. Copyright © 2007 John Wiley & Sons, Ltd.     

Model development and calibration for the coupled thermal,hydraulic and mechanical phenomena of the bentonite

In the international DECOVALEX-THMC project, five research teams study the influence of thermal-hydro-mechanical (THM) coupling on the safety of a hypothetical geological repository for spent fuel. In order to improve the analyses, the teams calibrated their bentonite models with results from laboratory experiments, including swelling pressure tests, water uptake tests, thermally gradient tests, and the CEA mock-up THM experiment. This paper describes the mathematical models used by the teams, and compares the results of their calibrations with the experimental data.