伶仃洋茅洲河口动力地貌演变过程

利用长系列的水文泥沙、水下地形和遥感影像等数据,通过数字地形高程模型和水动力数学模型等方法,探讨了伶仃洋茅洲河口的动力地貌演变过程及主要原因。结果表明:伶仃洋中滩海区近年冲刷态势明显,拦江沙与矾石浅滩呈现逐渐分离并有发育形成"新中槽"的演变趋势;茅洲河口门深槽的形成发育以落潮流动力作用为主,交椅湾深槽具有涨潮沟的性质,交椅沙形成发育对于稳定周边海区滩槽格局具有重要作用;大规模围涂造地和海床采砂等人类开发活动显著改变了伶仃洋的地形边界条件,进而影响河口水沙输移和滩槽格局,亟需加强监控。     

神府煤田张家峁煤矿烧变岩与水库水力联系研究

为了张家峁煤矿5-2煤工作面安全回采和常家沟水库水资源保护,根据水文地质调查结果,采用水位流量响应法确定了水库水是陈家塔沟泉水的来源;按照水库、烧变岩、泉点的地质关系分析了水库补给泉水的通道,认为4-2煤烧变岩与水库存在水力联系,为开采煤层上覆烧变岩帷幕截流工程提供了重要的依据。烧变岩帷幕截流工程及相应水文地质工作证明了研究成果。     

BOOK REVIEWS

Book Reviewed in this article: The Rice Economy of Asia . Randolph Barker and Robert W. Herdt with Beth Rose. Using Microcomputers: A Guidebook for Writers, Teachers, and Researchers in the Social Sciences . Blaine A. Erie—the Lake that Survived . Noel M. Burns. Geology and Society . Donald R. Coates. Caves and Karst of Kentucky . Percy H. Dougherty, ed. Altered Harvest: Agriculture, Genetics, and the Fate of the World's Food Supply . Jack Doyle. The Middle East and North Africa, A Political Geography . Alasdair Drysdale and Gerald H. Blake. Clamor at the Gates. The New American Immigration . Nathan Glazer, ed. Development and the Landowner: An analysis of the British experience . Robin Goodchild and Richard Munton. Discovering Landscape in England and Wales . Andrew Goudie and Rita Gardner. The Modern Plantation in the Third World . Edgar Graham and Ingrid Floering. Social Relations and Spatial Structures . Derek Gregory and John Urry, eds. The World Food Problem 1950–1980 . David Grigg. Costa Rica: A Geographical Interpretation in Historical Perspective . Carolyn Hall. The Urbanization of Capital: Studies in the History and Theory of Capitalist Urbanization . David Harvey Consciousness and the Urban Experience: Studies in the History and Theory of Capitalist Urbanization . David Harvey. Reviving Main Street . Deryck Holdsworth, ed. Rural Roads and Poverty Alleviation . John Howe and Peter Richards, eds. Uneven Development in Southern Europe: Studies of Accumulation, Class, Migration and the State . Ray Hudson and Jim Lewis, eds. Karst Geomorphology . J. N. Jennings. The Geomorphology of North-west England . R. H. Johnson, ed. Climate Impact Assessment: Studies of the Interaction of Climate and Society . Robert Kates, Jesse Ausubel, Mimi Berberian, eds. Public Service Provision and Urban Development . Andrew Kirby, Paul Knox, and Steven Pinch, ed. State and Market: The Politics of the Public and the Private . Jan-Erik Lane, ed. Living Cities . Twentieth Century Fund Task Force on Urban Preservation Policies. World Climatic Systems . John G. Lockwood. Urban Ethnicity in the United States. New Immigrants and Old Minorities . Lionel Maldonaldo and Joan Moore, eds. Culture and Conservation: The Human Dimension in Environmental Planning . Jeffrey A. McNeely and David Pitt, eds. The Andean Past. Land, Societies, and Conflicts . Magnus Mörner. Gaia: An Atlas of Planet Management . Norman Myers, ed. Progress in Industrial Geography . Michael Pacione, ed. Progress in Political Geography . Michael Pacione, ed. Rivers and Landscape . Geoff Petts and Ian Foster. Urbanization and Planning in the 3rd World: Spatial Perceptions and Public Participation . Robert B. Potter. One Island, Two Nations? A Political Geographical Analysis of the National Conflict in Ireland . D. G. Pringle. Circulation in Third World Countries . R. Mansell Prothero and Murray Chapman. The Ozarks Outdoors: A Guide for Fishermen, Hunters, and Tourists . Milton D. Rafferty. Suburban Burglary: A Time and a Place for Everything . George Rengert and John Wasilchick. Geomorphology and Soils . K.S. Richards, R.R. Arnett, and S. Ellis, eds. The Homes and Homeless of Post-War Britain . Frederick Shaw. Indochinese Refugees in America . Paul J. Strand and Woodrow Jones, Jr. Wild Horses and Sacred Cows . Richard Symanski. Forever Wild: Environmental Aesthetics and the Adirondack Forest Preserve . Philip G. Terrie. The Regional Economic Impact of Technological Change . A.T. Thwaites and R.P. Oakey, eds. The Good Life . Yi-Fu Tuan.     

闪电放电通道的三维结构特征

通过对闪电VHF辐射源高时空分辨率的三维观测资料的分析发现,无论云闪还是地闪其时间和空间分布特征可表明雷暴中的基本电荷结构。云内闪电放电不仅发生在上部正电荷区与中部主负电荷区之间,也同样会在中部主负电荷区与下部正电荷区之间发生,除极性相反之外,其它特征是一致的。云闪过程在最初的10一20ms内垂直向上(正常极性)或向下(反极性)发展,之后转为水平方向的传输。在正电荷区辐射点较多,闪电通道清晰;在负电荷区辐射点较少,且从闪电的起始位置以一种倒退的方式水平延伸闪电通道。云闪中的K型击穿不仅发生在闪电的后期,而且还发生在活跃期,并不时发展到正电荷区而触发新的闪电分叉。负地闪首次回击之前的梯级先导过程辐射较强,继后回击前的直窜先导的辐射较弱。回击之间闪电在云内水平发展,通道以细小的分叉为主要特征,其间不时有没有到地的企图先导过程发生。正地闪的先导过程基本没有可探测到的辐射点,在回击之前有一段云内过程,回击之后有更长的云内过程发展,其闪电通道不像负地闪那样精细,在回击之后的最初阶段辐射点较少,而在通道的顶端辐射点反而较多。正负地闪的发生发展特征有很大的不同,表明正、负极性的电荷击穿及传输过程的机制存在明显差异。     

薄层厚度定量解释研究

薄层厚度定量解释已成为能源勘探迫切需要解决的课题之一。目前薄层厚度定量预测方法繁多,本文简要地介绍薄层的基本概念、薄层理论以及国内外薄层厚度研究的现状,并重点介绍了道积分法,在此基础上利用正演模型和实际资料进行了深入的研究。     

黄土高原分形沟网研究

推测认为黄土高源沟网具有分形性。根据Hoton定律推导沟网分维计算式，确定沟网分形结构，分形理论求算得小流域沟网的分维D＝1．9接近于平面空间时的D＝2理论值。统计分析发现流域边界周长、长轴、短轴、长短轴比、汇合角等地貌指标随流域面积的变化。从而证明黄土高源流域的自相似性。     

长江口南港的水文泥沙环境及污染物输移

南港河道水域宽广,水体量大,动力条件强,悬沙含量较高且都是细颗粒物质,纳污容量大,具有较强的输运、稀释和自净能力。污水进入南港以后,污染物在河道中迁移转化,主要吸附在泥沙上。在外泄过程中污染物质在南港中往返逗留,循环输移,向底层、滩地、涨潮沟等地迁移,并在河海相接地带富集。     

槽波地震勘探的数学模型研究

为研究槽波的形成及地震时间剖面上的表现规律，利用非均匀各向同性介质的波动方程，应用有限差分法进行求解并编制了计算程度，给出了一个3层不对称模型的两分量计算结果实例。     

西部凹陷南部沙三段储层沉积特征及含油气性分析

西部凹陷南部为辽河油田的重点探区之一，具有十分优越的石油地质条件。本区在沙三期断陷活动强烈，发育了巨厚的深水泥岩和多期次缓坡型湖底扇沉积，为油气聚集成藏提供了丰富的油气源条件和储集条件。沙三段沉积时期，在西部凹陷南部发育有齐家-杜家台和锦州-欢喜岭两大湖底扇沉积体系。受物源区的距离、基底构造和主干断层活动的控制，湖底扇平面上具有分带性，可划分为内扇、中扇和外扇三个亚相带。齐杜和锦欢湖底扇在沙三早期规模较小，中期规模最大，晚期萎缩。本区沙三段储层物性普遍较差，以低孔-低渗、特低孔-特低渗储层为主，其中湖底扇中扇辫状沟道微相砂体储集性能最好，平面上依中扇辫状沟道→中扇前缘→外扇亚相储层物性由好变差。储集性能的优劣主要受母岩区岩性、沉积作用、成岩作用等多种因素控制。沙三段湖底扇砂体在区内分布广泛，处于成熟生油岩的包围之中，位于油气运移的有利指向上，成藏条件优越，勘探前景广阔。     

A LINEAR THEORY FOR DISTURBANCE OF COHERENT STRUCTURE AND MECHANISM OF SAND WAVES IN OPEN-CHANNEL FLOW

1 INTRODUCTIONT'he early theory for tUrbulent boundare layer assumed that the now adjacent to the wall is a lndnar innature and is named lndnar bottom layer Its thickness is about V/u*, Where V is the ldnehc viscosityand u* is the fuchon velocity. Towmsend (l956) first suggested the concePt of tUrbulent strUctUre andpointod out that there are isotroPic small scale nuctUation and quasi-periodic large scale strUcture in theshear flow Einstein and Li (l956) discovered by the flow moving…