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排序方式: 共有70条查询结果,搜索用时 15 毫秒
1.
焦明连 《海洋测绘》2005,25(4):32-34
针对《城镇地籍调查规程》和《城市测量规范》对光电测距(EDM)导线技术参数规定的不同,对低等光电测距导线的合理等级及各等级导线的技术标准进行了研究,并通过精度估算证明了各级导线精度的可靠性。  相似文献   
2.
赵生昊  杨磊 《气象科技》2016,44(5):822-827
利用2008—2013年MODIS 3级数据土地覆盖类型产品MCD12Q1及重庆市ADTD闪电定位资料,以重庆市内106°~107°E,29°~30°N范围的矩形区域为研究区域,结合频次、强度、时段、地貌等要素对局地内的地表覆盖种类与地闪分布关系进行了研究,结果表明:研究区内地闪分布在各地表覆盖种类上差异显著,在水域、农田、城镇上的闪电密度都高于平均值;地闪中轻中度闪电、强闪电的分布在同一地表覆盖种类上的差异明显,强闪电更易产生于水域、林地种类上;同一地表覆盖种类上地闪分布与季节的关系不明显;地闪活动在某些地表覆盖种类上的昼夜分布具有明显差异;植被覆盖面上的地闪分布与地貌条件关系密切,同一类覆盖面上的强闪电比例与海拔高度呈正相关关系。  相似文献   
3.
崎岖地形动植物栖息地生态环境遥感制图与应用   总被引:1,自引:1,他引:0  
传统制图方法周期长、成本较高,影响了大面积精细动植物栖息地生态环境制图的生产。鉴此,本文采用IKONOS(VHR)图像对香港郊野公园崎岖地形的动植物栖息地生态环境制图进行了研究。由于香港植被的多样性,而且观察的动植物相互作用出现于结构的层面,所以对动植物栖息地的分类应以结构为基础而非以植物为基础。本文利用图像处理技术,运用决策树之多层次地物导向分割分类(MOOSC)方法绘制九种动植物栖息地类型图。MOOSC方法和其他现有的几种分类方法相比,其分类精度高、成本低。  相似文献   
4.
Mathematical models of hydrocarbon formation can be used to simulate the natural evolution of different types of organic matter and to make an overall calculation of the amounts of oil and/or gas produced during this evolution. However, such models do not provide any information on the composition of the hydrocarbons formed or on how they evolve during catagenesis.From the kinetic standpoint, the composition of the hydrocarbons formed can be considered to result from the effect of “primary cracking” reactions having a direct effect on kerogen during its evolution as well as from the effect of “secondary cracking” acting on the hydrocarbons formed.This report gives experimental results concerning the “primary cracking” of Types II and III kerogens and their modelling. For this, the hydrocarbons produced have been grouped into four classes (C1, C2–C5, C6–C15 and C15+). Experimental data corresponding to these different classes were obtained by the pyrolysis of kerogens with temperature programming of 4°C/min with continuous analysis, during heating, of the amount of hydrocarbons corresponding to each of these classes.The kinetic parameters of the model were optimized on the basis of the results obtained. This model represents the first step in the creation of a more sophisticated mathematical model to be capable of simulating the formation of different hydrocarbon classes during the thermal history of sediments. The second step being the adjustment of the kinetic parameters of “secondary cracking”.  相似文献   
5.
为加强做好国土资源执法监察工作,文登市国土资源局在认真贯彻落实好国土资源部执法监察各项规定的同时,在建立健全村级土地协管员、信访信息员、土地监督员的基础上,全市全面推行"分级负责,层层监管"的执法新机制,动员全社会力量参与国土资源管理,变国土部门一家管为大家管,扭转了国土资源执法监察工作的被动局面,是当前做好国土资源执法监察工作的有效途径。  相似文献   
6.
Notes     
《The Journal of geography》2012,111(3):132-143
Abstract

J. N. L. Baker. The History of Geography. Barnes &; Noble, Inc., 105 Fifth Ave., New York 3, N.Y., 1963. xxviii and 266 pages with table of contents and index. $7.50.

R. J. Harrison Church. Environment and Policies in West Africa. D. Van Nostrand Co. Inc., 120 Alexander St., Princeton, N.J., 1963. 135 pages with table of contents, maps, diagrams and general index. $1.45.

Richard M. Highsmith, and J. Granville Jensen. Geography of Commodity Production, Second Edition. J. B. Lippincott Co., East Washington Sq., Philadelphia 5, Pa., 1963. 515 pages with table of contents, maps, photographs, graphs and index. $7.95.

Oliver H. Heintzelman and Richaid M. High-smith, Jr., World Regional Geography. Prentice-Hall, Inc., Englewood Cliffs, N.J., 1963, 2nd edition. 391 pages with table of contents, pictures, maps, diagrams, and index. $7.95.

Gerd Fraenkel with Lindley J. Stiles. Today's World in Focus: Israel. Ginn and Co., Statler Building, Boston 17, Mass., 1963. 122 pages with table of contents with black and white photographs with colored illustrations, appendices and bibliography. $1.40.

Thomas Sterling. Exploration of Africa. Horizon Caravel Books, 551 Fifth Ave., New York 17, N.Y., 1963. 153 pages with table of contents, maps, color and black and white illustrations and index. $3.95.

C. W. Harrison. Conservationists and What They Do. Franklin Watts, Inc., 575 Lexington Ave., New York 22, N.Y., 1963. 170 pages with table of contents and index. $3.95.

William Trout Chambers and Lorrin Kennamer, Jr. Texans And Their Land. The Steck Co., P.O. Box 16, Austin, Tex., 1963. 232 pages with table of contents, black and white pictures, colored maps, appendix, bibliography and index. $4.88.

Olive Burt. The First Book of Utah. Franklin Watts, Inc., 575 Lexington Ave., New York 22, N.Y., 1963. 66 pages with table of contents, general map of Utah, photographs and an index. $2.50.

Bernt Lloyd Wills. North Dakota: The Northern Prairie State. B. L. Wills, University of North Dakota, Grand Forks, N.D., 1963. 318 pages with table of contents, black and white pictures and black and white illustrations and index. $4.80.

Mary Foley Horkheimer and John W. Differ, (compilors and editors). Educators Guide to Free Filmstrips. Educators Progress Service, Randolph, Wis., 1963. 15th Annual Edition with 159 pages, table of contents and indices. $6.00.

Patricia Horkheimer Suttles, (editor). Educators Guide to Free Social Studies Materials. Educators Progress Service, Randolph, Wis., 1963. 402 pages with XV pages editorial comment and table of contents. $6.75.

C. B. Hitchcock and O. M. Miller. Nine Glacier Maps, Northwestern North America with Text. Special Publication No. 34. American Geographical Society, 156th St. and Broadway, New York 32, N.Y., 1960. 22 pages with table of contents, three appendices, one table, one locational text map, 15 photographs and nine separate topographic maps. $3.00.

Harry M. Caudill. Night Comes To The Cumberlands. Little, Brown &; Co., 128 Oliver St., Paterson 1, N.J., 1963. 394 pages with table of contents and black and white photographs. $6.75.  相似文献   
7.
8.
等价类对数据库查询计划的生成与优化有重要作用。为了减少查询计划的搜索空间,空间数据库管理系统(Ingres),将空间拓扑关系视为等价关系,并将空间拓扑关系沉入查询树底端先执行。由于非等值空间关系谓词不具备等价类的传递性,常常导致一些空间查询不能正确执行。本文提出了空间约束对的概念,即将非等值空间谓词连接的2个空间列、或某表的空间列与其空间索引表中的KEY列(记录了MBR)视为空间约束对。空间约束对除不具备等价关系的自反性、对称性和传递性外,其启发式策略仍可沿用等价类的相关规则。此外,本文还探讨了空间约束对在Ingres中的实现,并开展了相关的实证研究。实验表明:将空间拓扑谓词两端的属性视为空间约束对后,原本不能正确执行的查询语句,在改后的Ingres中能正确地找到较优执行计划。  相似文献   
9.
湿地生态风险管理   总被引:2,自引:0,他引:2  
结合生态学相关知识,将生态风险管理具体应用到湿地的生态风险管理中。从湿地生态风险管理过程的规划、管理目标、生态风险评估、风险处理等方面对湿地生态风险管理进行了探讨。在湿地生态风险评价过程中进一步运用经济学方法进行了湿地风险综合分析,使湿地生态风险管理更有效。对于湿地生态风险管理,应根据不同的风险程度采取不同的措施或者方法,提出了4种湿地风险管理措施。  相似文献   
10.
BOOK REVIEWS     
Book Reviewed in this article: Unfairly Structured Cities . Blair Badcock Religion and Rural Revolt . Janos M. Bak and Gerhard Benecke The Industrial Geography of Canada . Anthony Blackbourn and Robert G. Putnam The Cuban-American Experience, Culture, Images, and Perspectives. Thomas D. Boswell and James R. Curtis Quaternary Paleoclimatology . R. S. Bradley Development and Crisis in Brazil, 1930–1983 . Luiz Bresser Pereiras Centres of Origin in Biogeography . John C. Briggs Analytical Urban Geography . Martin Cadwallader Geomorphology . Richard J. Chorley , Stanley A. Schumm, and David E. Sugden South Africa: The Impact of Past Geographies . A. J. Christopher The Geography of Underdevelopment. A Critical Survey . D. K. Forbes Health Care in Developing Countries . Wilbert M. Gesler Place to Grow Old: The Meaning of Environment in Old Age . Stephen M. Golant The Emerging Marine Economy of the Pacific . Chennat Gopalakrishnan An Introduction to Agricultural Geography . David B. Grigg The Soviet Union: A Geographical Study . G. Melvyn Howe Geographical Aspects of Health: Essays in Honour of Andrew Learmonth . N. D. Mc Glashan and J. R. Blunden Physical Geography: A Landscape Appreciation . Tom L. Mc Knight Mountain Experience. The Psychology and Sociology of Adventure. Richard G. Mitchell Jr . Systematic and Regional Biogeography. Stanley A. Morain The Economic Transformation of American Cities. T. J. Noyelle and T. M. Stanback , Jr . Normal Accidents: Living With High-Risk Technologies. Charles Perrow Vanishing Farmland: A Legal Solution for the States. Sarah E. Redfield Applied Methods of Regional Analysis: The Spatial Dimensions of Development Policy. Dennis A. Rondinelli Urbanization in Romania. A Geography of Social and Economic Change Since Independence. Per Ronnas Statistical Techniques in Geographical Analysis. Gareth Shaw and Dennis Wheeler The Granite Garden: Urban Nature and Human Design. Anne Whiston Spirn Political Geography: Recent Advances and Future Directions. Peter Taylor and John House Geographia y Medio Ambiente. Manuel Valenzuela -Rubío Nãgara and Commandery: Origins of the Southeast Asian Urban Traditions. Paul Wheatley The Common Fisheries Policy of the European Community. Mark Wise Geography and Gender. Women and Geography Study Group of the IBG Technological Hazards. D. J. Zeigler , J. H. Johnson , S. D. Brunn  相似文献   
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