闽中北冰雹概念模型

通过对近 1 0年 6 4次降雹过程进行分析 ,将天气类型分为 3种 ,然后归纳总结各天气型下的雹云源地、路径、回波特征、物理量特征 ,建立闽中北冰雹 3种概念模型     

浅析GIS空间数据不确定性概念模型

对空间数据不确定性的研究，大多数都是针对数据本身进行的，很少针对地理空间数据实际应用的不确定性展开研究，由于各种不确定性之间也常常是相互联系、相互影响，各种不确定性之间也存在很大的相关性。对地理空间数据的应用范围，以及在规定的应用范围内将产生怎样的应用结果进行不确定性评定，远比只研究地理空间数据本身的不确定性更为复杂。从目前GIS的空间数据不确定性所存在的问题出发．在介绍空间数据不确定性概念、形成的原因及一般的空间数据流程的基础上，对空间数据不确定性概念模型的建立及其模型进行了阐述，可以对空间数据不确定性的研究起到一定的借鉴作用。     

Analytical Solutions for Pore-Fluid Flow Focusing Within Inclined Elliptic Inclusions in Pore-Fluid-Saturated Porous Rocks: Solutions Derived in an Elliptical Coordinate System

Exact analytical solutions have been derived rigorously for the pore-fluid velocity, pore-fluid-flow focusing factor, stream function and excess pore-fluid pressure around and within a buried inclined elliptic inclusion in pore-fluid-saturated porous rocks. The geometric characteristics of the buried inclined elliptic inclusion are represented by the aspect ratio and dip angle of the inclusion, while the hydrodynamic characteristic is represented by the permeability ratio of the elliptic inclusion to its surrounding rock. Since an elliptic inclusion of any aspect ratio can be used to approximately represent geological faults and cracks, the present analytical solutions can be used to investigate the pore-fluid-flow patterns around buried faults and cracks within the crust of the Earth. Therefore, the present analytical solution not only provides a better understanding of the physics behind the pore-fluid-flow focusing problem around and within buried faults and cracks, but also provides a valuable benchmark solution for validating any numerical method in dealing with this kind of pore-fluid-flow focusing problem. The pore-fluid-flow focusing factor of a buried elliptic inclusion is demonstrated to be dependent on the aspect ratio, the permeability ratio and the dip angle.     

基于能量原理的钢筋混凝土筒体结构抗震性能研究

本文通过能量法研究了钢筋混凝土筒体结构的抗震性能。文中采用振型分解法按等效单自由度体系求解筒体结构的滞回输入能;用pushover法分析了滞回耗能在结构层间的分布规律及结构自身的耗能能力;根据楼层滞回耗能与弹塑性层间位移的关系求出了薄弱层的弹塑性位移。对一高层钢筋混凝土框架-筒体结构在7度罕遇地震下的抗震性能进行了评估,通过与非线性动力时程分析的对比,证明了方法的可行性。     

基坑围护设计与实测分析比较

通过不同围护软件分析计算并与实测结果进行比较 ,指出土层水平抗力系数“m”取值的关键性 ,基坑开挖是一个动态而复杂的过程 ,理论计算会有一定的差距     

黄河壶口瀑布国家地质公园开发建设构想

地质公园是地质遗迹景观和生态环境的重点保护区,是地质科学研究与普及的基地。黄河壶口瀑布的形成经历了一个复杂而漫长的演化过程。显露在河床及河谷两岸的地质遗迹,揭示着黄河壶口瀑布演化进程,对研究黄河发育史、晋陕峡谷的形成、瀑布成因、演化等问题,具有重要的科学理论价值。因此对黄河壶口瀑布国家地质公园的地质旅游资源进行了科学的综合评价,提出了开发构想。使黄河壶口瀑布地质地貌能得以科学的保护与合理的开发利用,不仅要将壶口瀑布建成我国著名的地质公园,更要将其建成我国的瀑布科学研究中心和科普教育基地。     

流域地貌演化的不同阶段沟壑密度与切割深度关系研究

主要探讨了在流域地貌演化的不同阶段,沟壑密度与切割深度的复杂关系,建立了沟壑密度随切割深度变化的理论极值模型及相应阶段的函数,补充了各演化阶段地貌形态要素的定量、定性描述;反之,可用沟壑密度与切割深度的关系推断流域地貌的演化阶段。     

工程测量教学中误差基本概念的应用

主要分析了工程测量教学中误差基本概念的应用,描述了偶然误差和闭合差等概念,举出了教学中的一些例子。     

Principal axes of M-DOF structures Part Ⅱ: Dynamic loading

This paper is the second in a two-part series that discusses the principal axes of M-DOF structures subjected to static and dynamic loads. The primary purpose of this series is to understand the magnitude of the dynamic response of structures to enable better design of structures and response modification devices/systems. Under idealized design conditions, the structural responses are obtained by using single direction input ground motions in the direction of the intended response modification devices/systems, and by assuming that the responses of the structure is decoupleable in three mutually perpendicular directions. This standard practice has been applied to both new and retrofitted structures using various seismic protective systems. Very limited information is available on the effects of neglecting the impact of directional couplings (cross effects of which torsion is a component) of the dynamic response of structures. In order to quantify such effects, it is necessary to examine the principal axes of structures under both static and dynamic loading. In this two-part series, the first paper is concerned with static loading, which provides definitions and fundamental formulations, with the conclusion that cross effects of a statically loaded M-DOF structure resulting from the lack of principal axes are of insignificant magnitude. However, under dynamic or earthquake loading, a relatively small amount of energy transferred across perpendicular directions is accumulated, which may result in significant enlargement of the structural response. This paper deals with a formulation to define the principal axes of M-DOF structures under dynamic loading and develops quantitative measures to identify cross effects resulting from the non-existence of principal axes.     

稳定同位素和微量元素在多源多汇体系中地球化学行为的理论模拟

根据地质体系多源多汇的特点,引进了一种新的定量地球化学理论模型,适用于模拟稳定同位素和微量元素在具有多个物质来源和多种分馏途径的地质体系中的变化规律。运用本文多源多汇模型研究岩浆同化-分异结晶过程中微量元素和稳定同位素的行为,所得的结果与前人AFC模型结果一致。运用此多源多汇模型对岩浆水与大气水混合过程中结晶出的石英进行模拟计算,发现其氧同位素组成随着结晶温度的降低而变大。大气中甲烷的产生和消耗有多种途径,是一种多源多汇体系,运用此模型研究它的碳同位素组成,发现其值随着甲烷总量的增多而变大。多源多汇模型不仅从更高的层次上包含了简单分馏模式、多元混合模式和AFC模式,而且可以研究这些模式不能解决的复杂地球化学过程。