化石群落与层序地层的耦合关系研究——以塔里木盆地西部中新生代有孔虫群落与层序地层关系研究为例

本文研究的是大陆边缘海以底栖有孔虫为主的化石群落与层序地层的关系。海平面变化是控制化石群落演替和识别划分层序的主要因素。化石群落在一个完整海水进退旋回中呈机会种群落、平衡种群落、终极种群落演替变化,在化石丰度、多样度、均衡度、成壳类型等方面分异显著,与层序地层的三级层序的海进体系域、凝缩期沉积、高位体系域具有密切的耦合关系。化石群落的演替变化是对海洋环境变迁的能动反映。因此,化石群落的研究可以帮助识别和优化层序、沉积体系域和层序界面,从而为层序地层的准确识别划分提供新的思路。     

淮南地区煤储层含气性总体特征

煤层含气性是煤层气成藏的一个基本要素,是煤层气勘探开发决策的重要依据之一。本文主要从煤储层含气性的区域展布、层域展布以及深度展布三个方面讨论煤层含气性的变化规律,归纳出了淮南地区煤储层含气性总体特征,为选区资源评价提供基础研究。     

西昆仑—塔里木—天山岩石圈深地震探测综述

沿新疆地学断面走廊域实施了3种深地震探测方法：近垂直深地震反射剖面、宽角反射与折射深地震测深剖面和移动式宽频地震观测，揭露出西屁仑-塔里木-天山岩石圈的结构与横向变化，发现了塔里木大陆地块与青藏高原西北部西昆仑造山带碰撞的地震学证据，揭示出天山与塔里木、天山与准噶尔，以及昆仑山与塔里木之间的岩石圈尺度盆山耦合关系。阶段成果发表后引起国内外学者广泛注意，本文结合相关资料对这些新成果进行了系统综述，旨在对比研究青藏高原南北两缘不同的碰撞变形之深部过程。     

象头山自然保护区的气候特征

象头山自然保护区地处南亚热带湿润季风气候区，具有热量丰富、降水充沛、室气湿润、湿季长、干季短、植物生长期长、风向随季节改变、气候垂直变化大等特点，有大风、台风和雷暴危害。     

山西榆次地裂缝灾害评价的GIS与ANN耦合技术研究

现代地裂缝在世界许多国家普遍存在，已成为当今世界范围的一种主要地质灾害。本文详尽分析了山西榆次地裂缝灾害的各个致灾因子的基础上，利用地理信息系统（GIS）技术建立了地学信息的各个子专题层图；然后采用以工程技术手段模拟人脑神经网络结构和功能特征的人工神经网络（ANN）技术，构建出地裂缝灾情非线性评价模型，榆次地裂缝灾害进行了非线性评价，为榆次城建、环保和国土规划等部门的正确决策提供了重要的科学依据。     

A constitutive model for bonded geomaterials subject to mechanical and/or chemical degradation

The mechanical behaviour of bonded geomaterials is described by means of an elastoplastic strain‐hardening model. The internal variables, taking into account the ‘history’ of the material, depend on the plastic strains experienced and on a conveniently defined scalar measure of damage induced by weathering and/or chemical degradation. For the sake of simplicity, it is assumed that only internal variables are affected by mechanical and chemical history of the material. Despite this simplifying assumption, it can be shown that many interesting phenomena exhibited by weathered bonded geomaterials can be successfully described. For instance, (i) the transition from brittle to ductile behaviour with increasing pressure of a calcarenite with collapsing internal structure, (ii) the complex behaviour of chalk and other calcareous materials in oedometric tests, (iii) the chemically induced variation of the stress and strain state of such kind of materials, are all phenomena that can be qualitatively reproduced. Several comparisons with experimental data show that the model can capture the observed behaviour also quantitatively. Copyright © 2003 John Wiley & Sons, Ltd.     

Alfvén wave coupling in the auroral current circuit

Auroral phenomena are controlled by the geomagnetic field.Since the terrestrial field lines connect the auroral oval to the equatorial region at large distances, the collisionless plasma in this remote space environment can act as a power supply for the high-latitude upper atmosphere where auroral emissions take place. The coupling process is intimately linked to currents which flow across the local magnetic field direction both in the equatorial part and at the atmospheric end of the auroral field lines. These two auroral key regions are connected through currents flowing along the terrestrial field lines, thereby completing the auroral current circuit. Such field-aligned currents are carried by Alfvén waves, that is, magnetohydrodynamic shear waves, which are thus a means to exchange momentum and energybetween rather remote parts of the geomagnetically controlledspace environment. Auroral dynamics is further affected by a third key region in the auroral current circuit, namely the auroral acceleration region, where parallel electric fields accelerate particle to keV energies. This review focuses on key region coupling through Alfvén waves. Continuity requirements for currents and electric fields provide a convenient means to describe the interaction of Alfvén waves with different plasma regimes. Basic coupling aspects can be demonstrated with the help of a simplified model. Inhomogeneities and nonlinear feedback can lead to resonance effects and instabilities.     

NUMERICA STUDY OF THUNDERSTORM ELECTRIFICATION WITH A THREE-DIMENSIONAL DYNAMICS AND ELECTRIFICATION COUPLED MODEL—MODEL DESCRIPTION AND PARAMETERIZATION OF ELECTRICAL PROCESSES*

A new three-dimensional dynamics and electrification coupled model has been developed for investigating the characteristics of microphysics,dynamics and electrification inside thunderstorms.This model is basically modified from a three-dimensional,time-dependent,and dual-parameter cloud model originally established in IAP (Institute of Atmospheric Physics) and a two-dimensional axisymmetric cloud dynamics and electrification coupled model.Primary modifications to the model include not only the coupling of electrification with dynamical and microphysical processes,but also the lightning discharge process and screening layer effect at the cloud top as well.Apart from including a full treatment of small ions with attachment to six classes of hydrometeors,the inductive and non-inductive charging mechanisms are more specifically considered.A case simulation of July 19.1981 CCOPE is performed aiming to validate the potential capability of the model.Comparison between model results and observations reveals that the model has the capacity to reproduce many of the observed characteristics of thunderstorms in dynamical,microphysical,and electrical aspects.     

县域自然资源评价体系及量化方法——以云南省为例

针对中国以往的自然资源评价存在的一些问题，对新提出的评价体系和量化方法进行介绍。包括县域评价对象、评价指标的4条确定原则和相应的3评价指标体系、均权和专家分法的可选择权重确定方式、均权模型和模糊综合评价模型的可选择方式、单一评价和综合评价的可选择方式、评价软件的主要步骤。对该软件的设计特点可概括为：良好的运行 平台，可视化编程，操作容易；数据库与图形库的有机结合；采用面向对象的DELPHI与MO结合的方式进行编程；系统管理、地图管理和资源评价三大模块及功能的合理配置。     

Biodiversity and conservation in the Tibetan Plateau

The Tibetan Plateau (Qinghai-Xizang Plateau) is a unique biogeographic region in the world, where various landscapes, altitudinal belts, alpine ecosystems, and endangered and endemic species have been developed. A total of 26 altitudinal belts, 28 spectra of altitudinal belts, 12,000 species of vascular plant, 5,000 species of epiphytes, 210 species of mammals, and 532 species of birds have been recorded. The plateau is also one of the centers of species formation and differentiation in the world To protect the biodiversity of the plateau, about 80 nature reserves have been designated, of which 45 are national or provincial, covering about 22% of the plateau area. Most of the nature reserves are distributed in the southeastern plateau. Recently, the Chinese government has initiated the “Natural Forests Protection Project of China,” mainly in the upper reaches of the Yangtze and Yellow rivers. “No logging” policies have been made and implemented for these areas.