P‐wave transmission across fractures with nonlinear deformational behaviour

Stress wave attenuation across fractured rock masses is a great concern of underground structure safety. When the wave amplitude is large, fractures experience nonlinear deformation during the wave propagation. This paper presents a study on normal transmission of P‐wave across parallel fractures with nonlinear deformational behaviour (static Barton–Bandis model). The results show that the magnitude of transmission coefficient is a function of incident wave amplitude, nondimensional fracture spacing and number of fractures. Two important indices of nondimensional fracture spacing are identified, and they divide the area of nondimensional fracture spacing into three parts (individual fracture area, transition area and small spacing area). In the different areas, the magnitude of transmission coefficient has different trends with nondimensional fracture spacing and number of fractures. In addition, the study reveals that under some circumstances, the magnitude of transmission coefficient increases with increasing number of fractures, and is larger than 1. Copyright © 2006 John Wiley & Sons, Ltd.     

△T球体异常的三元解释法

在△Ｔ异常解释课题中，一个新的角度参量─—视磁化特征角的拟定，最大限度地简化了球体磁场表达式。从而才有可能通过特殊解法，给出了球体磁场的极值与拐点公式。作者据此建立了四种不受正常场制约、仅需异常的局部持征曲线即可全面解释三度异常的解释方法。屏障分解、叠加判别、三元迭代的设计，为解释三度体叠加异常给出了简单而易行的途径。     

Species composition and distribution of marine nematode community in the North Taiwan Strait

I~IOW~ne nelnatode is a ban gIOup of benthic OrgAnsrns. Abbot 5 000 spotes Of free-livingnelnatedes have ben dedbo so far, and it has ho estimated that abbot 20 (XX) are as yetunknoWn. Chinese bothologist has Paid attention to marine nelnatodes in China seas in yare. The spatial distribution and shoes commotion of marine nelnatedes in the HUanghe EstUary, Qinhuangdao waters, QingdaO Bay and Xiamen ~ have ho reported (Zhang etal., 1990, 1991, 1993; ac and Li, 1998). ~ new shoes in the…     

云南东川因民铜矿金矿化特征及成因初探

因民铜矿发育两种金矿化类型:一是铜矿的伴生金;二是热液构造蚀变岩型。化探样品分析结果显示,金矿化主要赋存于金箔箐断层上、下盘的角砾状蚀变岩内,空间上受岩性和断裂构造的双重控制。邻区拖布卡金矿的成矿地质背景与本区相似,在成矿地质年代上作以类比推测,认为喜马拉雅期是主成矿期。另外通过对光片镜下和化探原生晕样聚类分析研究,发现构造蚀变岩型金矿化具明显的多期多阶段性及热液特征。     

Developing Universities into Learning Organizations

INTRODUCTIONThenotionof“learningorganization”hasbecomeanewbuzzwordinthemanagementandbusinesslitera turefromthelate 1980s (WangandAhmed ,2 0 0 3;Stewart,2 0 0 1;Garavan ,1997) .Thereappearstobemoreconsensusaboutthatonesourceofcompetitivead vantageistheabilityandrateatwhichanorganizationcanlearnandreactmorequicklythanitscompetitors(Stewart ,2 0 0 1;Garavan ,1997;Senge ,1990 ) ,soanumberofcompaniesandorganizationsaspiretocreateanddevelopintolearningorganizationsinordertofacili tatecontin…     

丽江大研镇震灾分布和地脉动测量结果之间的相关性

丽江７．０级地震后，大研镇被毁建筑物的地理分布呈显４条条带，伤亡人员的地理分布和上述条带重合。９１个短周期地脉动测点的观测资料表明，分布在上述条带内的大多数测点，其卓越周期大于０．３Ｓ；条带外的测点，其卓越周期一般在０．１Ｓ左右。作认为卓越周期和烈度异常之间良好的相关性，是因为地脉动卓越周期和地方震的频谱之间存在良好的相关性。     

一个被动大陆边缘的“开”“合”史及找矿标志——以赣西北震旦系至下古生界为例

本文根据赣西北地区震旦系至志留系基本层序和板内构造演化,可把古板块构造发展划分为4个阶段:开裂期(Z_1l-Z_2p)以中、小规模的重力流和凝缩段为特征;成熟发展期(∈_1-∈_3~1),以沉降沉积作用为主;萎缩期(∈_3~2-O_2h)以大规模重力流和混生动物群为特征;闭合期(O_3-S_3)以双幕式沉积为特征。同时阐述了在板块发展的各个阶段,不能忽视其成矿作用。     

华东南中新生代伸展构造时空演化与铀矿化时空分在

本文运用大陆伸展构造理论，论述了华东南地区中新生代以来伸展构造的分布规律，分析了不同类型伸展构造的时空演化特点。在此基础上，应用华东南地区不同类型铀矿床已有的成矿年龄资料，研究了伸展构造活动与区域铀成矿作用之间的联系，不同类型伸展构造与不同类型铀矿床之间在空间分布和时间演化上的对应关系。认为伸展构造活动产生的有利构造环境是导致铀成矿作用产生的根本原因，伸展构造活动的脉动性及其相应的岩浆作用决定了铀成矿作用的多期多阶段性，不同地区伸展构造活动的先后决定了不同类型铀矿床成矿作用的时序和空间分布。文章最后认为，由于伸展构造活动对区域铀矿化的这种明显控制关系，本区不同类型铀矿化成矿机理具有统一性。     

DYNAMIC VARIATIONS OF WATER QUALITY IN TAIHU LAKE AND MULTIVARIATE ANALYSIS OF ITS INFLUENTIAL FACTORS

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地理信息系统中数据产品的标准化

本文概述了地理信息系统在我国的兴起和发展及其国外背景和应用前景。论述了数据产品在地理信息系统中的重要性及其标准化的重要性和必要性。简单地提出了标准化的解决方法，以便参考。从而呼请有关部门对这一实际问题给予足够的重视。