湘南晚泥盆世佘田桥期碳酸盐块状流沉积特征     

蒋德和  曾允孚 《湖南地质》1990,9(4):32-38

湘南晚泥盆世佘田桥期表现为东西两侧高而中部低陷的古地理面貌。两侧为碳酸盐台地,中间为深水台盆。在台盆、台地之间斜坡地带和台盆边缘,堆积了类型繁多的碳酸盐块状流沉积物。它们由两类在成因和分布上有密切联系的沉积体系组成,一类为重力崩落或滑移体系,包括岩崩、滑动和滑塌沉积,另一类为重力流体系,包括碎屑流、浊流和颗粒流沉积。在层序上它们虽作有规律的组合层序,但并不是完整的类型,而出现较大的变异性。已发现的组合层序有①滑塌沉积—碎屑流沉积,②碎屑流—高密度浊流—低密度浊流沉积,③变密度颗粒流—浊流沉积。它们沿近南北向的台盆的两侧边缘呈条带状分布,东侧位于临武香花岭至桂阳莲塘一带,重力流厚度可达150m左右,西侧位于道县虎岩坝至双牌县城一带,重力流厚只30—50m,反映了台盆边缘两侧构造活动强度不一致,东侧强,西侧弱。  相似文献   

Drainage basin peak discharge rating curve     

Wilbur F. Rogers  Vijay P. Singh 《水文研究》1988,2(3):245-253

The stream gauge rating curve for a drainage basin can be transformed into a drainage basin peak discharge rating curve that is more stable than the rating curve from which it is derived. The resulting drainage basin peak discharge rating curve can be used to predict peak discharge, identify anomalous discharges caused by channel obstructions or other causes, evaluate the effect of flood retarding structures, and evaluate historical records. The drainage basin peak discharge rating curve is valid for drainage basins of any size, for any discharge up to the time of concentration, and for snowmelt.  相似文献   

BOOK REVIEWS     

《The Professional geographer》1988,40(3):347-378

Books reviewed in this article: The Mexican Colonial Copper Industry. Elinore M. Barrett . The Control Revolution: Technological and Economic Origins of the Information Society . James R. Beniger . Land Degradation and Society . Piers M. Blaikie And Harold C. Brookfield , Eds . La carte, mode d'emploi. Roger Brunet . France: les dynamiques du territoire . Roger Brunet AND Jacques Sallois , EDS. At the Crossroads—The Mineral Problems of the United States . Eugene N. Cameron . A Census of One Billion People , Papers for International Seminar on China's 1982 Population Census. Li Chengrui , ED. Les Milieux “Naturels” du Globe . Jean Demangeot . The Geophysiology of Amazonia: Vegetation and Climate Interactions : Robert E. Dickinson , ED. Tenn-Tom Country . James F. Doster And David C. Weaver . Family Farming in Europe and America . Boguslaw Galeski And Eugene Wilkening , EDS. The Geography of Urban Transportation . Susan Hanson , Ed. Combating Desertification in Developing Countries . J. K. Jain , ED. Cartography in France—1660–1848. Science, Engineering and Statecraft . Josef W. Konvitz . Distribution of Distances in Pregeographical Space . Hans Kuiper . Physical Geography Lab Manual: A New Experimental Approach . Neal G. Lineback And John M. Harlin . Physical Geography: A Landscape Appreciation , 2nd ed. Tom L. Mc Knight . The Desert Is No Lady: Southwestern Landscapes in Women's Writing and Art . Vera Norwood And Janice Monk , EDS. France: A Geographical, Social, and Economic Survey . Philippe Pinchemel , translated, by D. Elkins and T. H. Elkins. Gene Banks and the World's Food . Donald L. Plucknett , Nigel J. H. Smith , J. T. Williams , And N. Murthi Anishetty . Latin American Development: Geographical Perspectives . David Preston , Ed. Making Sense of Development: An Introduction to Classical and Contemporary Theories of Development and Their Application to Southeast Asia . P. W. Preston . The History of the Countryside. Oliver Rackham . The Third World in Perspective . H. A. Reitsma AND J. M. G. Kleinpenning . The Industrial Geography of Australia . David C. Rich . The Recruiting Game , 2nd Ed., revised. John F. Rooney , JR. A Cultural Geography of North American Indians . Thomas E. Ross AND Tyrel G. Moore , EDS. Eastern Europe . Dean S. Rugg . Human Territoriality: Its Theory and History . Cambridge Studies in Historical Geography: 7. Robert David Sack . Experimental Fluvial Geomorphology . Stanley A. Schumm , M. Paul Mosley , AND William E. Weaver . The New Urban Landscape . David Schuyler . Atlas of American Women . Barbara Gimla Shortridge . Impacts of Hazardous Technology: The Psycho-Social Effects of Restarting TMI-1 . John Sorensen , Jon Soderstrom , Emily Copenhaver , Sam Carnes AND Robert Bolin . Modern Physical Geography , 3rd Ed., (Third Edition). Arthur N. Strahler AND Alan H. Strahler . India: Economic Resource Base and Contemporary Political Patterns . B. L. Sukhwal .  相似文献   

A constraint to the Wisconsinan glacial history,Canadian Arctic Archipelago     

Alan Taylor 《第四纪科学杂志》1988,3(1):15-18

Thick ice-bearing permafrost is not observed today beneath the deeper channels of the central Queen Elizabeth Islands, Canadian Arctic Archipelago. Analysis of a precision temperature log recently obtained at an offshore well near Ellef Ringnes Island indicates that the thermal regime beneath the seabed is in equilibrium with today's marine environment. If thick permafrost similar to that observed on land today had existed in the Pleistocene in areas that are presently offshore, then such permafrost must have started melting no later than 25000 years ago in order to allow the present thermal regime to evolve. This suggests that the inter-island channels must have been water-filled at least by that date.  相似文献   

ENHANCING AND USING A SENSE OF PLACE WITHIN URBAN AREAS: A ROLE FOR APPLIED CULTURAL GEOGRAPHY     

David A. Lanegran 《The Professional geographer》1986,38(3):224-228

Basic concepts of cultural historical geography have been applied to a variety of community issues in St. Paul, MN. Through the process a sense of place has been developed at several scales. This inclusive sense of place has provided a link among various factions and made possible several compromises in land use and economic development issues. Most of the work was done through undergraduate field seminars.  相似文献   

Hot cores: probes of high-redshift galaxies?     

C. J. Lintott  S. Viti  D. A. Williams  J. M. C. Rawlings  I. Ferreras 《Monthly notices of the Royal Astronomical Society》2005,360(4):1527-1531

The very high rates of second generation star formation detected and inferred in high-redshift objects should be accompanied by intense millimetre-wave emission from hot core molecules. We calculate the molecular abundances likely to arise in hot cores associated with massive star formation at high redshift, using several different models of metallicity in the early Universe. If the number of hot cores exceeds that in the Milky Way Galaxy by a factor of at least 1000, then a wide range of molecules in high-redshift hot cores should have detectable emission. It should be possible to distinguish between different models for the production of metals and hence hot core molecules should be useful probes of star formation at high redshift.  相似文献   

Geomorphological and Pedological Investigations on the Glacial History of the Kali Gandaki (Nepal Himalaya)     

Markus Wagner 《GeoJournal》2005,62(3-4):91-113

In semi-arid orographic left tributaries of the Kali Gandaki at the northern and western flank of the Nilgiri Himal, glacio-geomorphological and pedological investigations were carried out on prehistoric moraines. Geomorphological relief analysis was derived from other literature and the own fieldwork of the author. The resulting glacial chronology was used as benchmark to explore the limits of different pedological dating methods regarding the degree of soil development. These methods are based on iron fractionation, total element contents and particle size distribution. In general the different glacial stages are mirrored correctly in the relative graduation of soil development. The ratio of well crystallised pedogenic iron-oxides to the total iron content and the ratio fine clay to total clay are most suitable, because they are almost independent from existing changes in the lithological composition. The total element based weathering indices are less suitable, because they react highly sensitive to the geology dependent shift to higher carbonate contents. Most of the grain size based weathering indices are inapplicable because of the typically high textural variability within till deposits.  相似文献   

共和6.9级地震震前形变异常     

张尊和  赵振才  丁平 《大地测量与地球动力学》1992,(1)

本文介绍了共和地震后所测到的源兆型大地形变异常,讨论了异常出现的时间、空间及异常与区域构造应力场的关系。指出形变测量手段有能力捕捉到此种地震前兆信息。  相似文献   

Shocks and shells in hot star winds     

A. Feldmeier  J. Puls  C. Reile  A. W. A. Pauldrach  R. P. Kudritzki  S. P. Owocki 《Astrophysics and Space Science》1995,233(1-2):293-299

Radiation-driven winds of hot, massive stars showvariability in UV and optical line profiles on time scales of hours to days.Shock heating of wind material is indicated by the observed X-ray emission. We present time-dependent hydrodynamical models of these winds, where flowstructures originate from a strong instability of the radiative driving. Recent calculations (Owocki 1992) of the unstable growth of perturbations were restricted by the assumptions of 1-D spherical symmetry and isothermality of the wind. We drop the latter assumption and include the energy transfer in the wind. This leads to a severe numerical shortcoming, whereby all radiative cooling zones collapse and the shocks become isothermal again. We propose a method to hinder this collapse. Calculations for dense supergiant winds then show: (1) The wind consists of a sequence of narrow and dense shells, which are enclosed by strong reverse shocks (with temperatures of 10⁶ to 10⁷ K) on their starward facing side. (2) Collisions of shells are frequent up to 6 to 7 stellar radii. (3) Radiative cooling is efficient only up to 4 to 6R _*. Beyond these radii, cooling zones behind shocks become broad and alter the wind structure drastically: all reverse shocks disappear, leaving regions ofpreviously heated gas.  相似文献   

郑州CINRAD风暴追踪产品误差统计分析     

牛淑贞  张一平  乔春贵  史一丛  袁小超 《气象》2018,44(10):1318-1324

利用2009—2016年5—9月郑州新一代天气雷达资料,对5615个单体回波按不同预报时效、不同生命史和不同类型强对流的风暴追踪信息产品进行统计,较系统地分析了单体回波的距离误差和方向误差,探讨了实况与预报的偏差方向。结果表明:30和60 min距离误差分别为9. 3和16. 9 km,方向误差变化不大,随着预报时效的延长,距离误差增大;生命史≤1h、1～2 h和超过2 h的30 min预报平均距离误差分别为9. 8、8. 8和7.7 km,方向误差分别为25. 2°、25. 7°和22.8°;生命史在1～2 h和超过2 h的60 min预报平均距离误差分别为17. 3和15. 9 km,方向误差为24. 4°和22. 7°,随着单体生命史的延长,方向和距离误差呈减小趋势;西北气流型、西南气流型两种类型单体回波和整体误差一致,两种类型回波单体30和60 min方向和距离误差基本相当;不同类型、不同预报时效统计均为实况偏于预报路径右侧的次数多于偏左的次数,30和60 min偏右比例分别为57. 5%和55.6%。  相似文献