全文获取类型
收费全文 | 2329篇 |
免费 | 355篇 |
国内免费 | 217篇 |
专业分类
测绘学 | 483篇 |
大气科学 | 181篇 |
地球物理 | 674篇 |
地质学 | 629篇 |
海洋学 | 202篇 |
天文学 | 11篇 |
综合类 | 179篇 |
自然地理 | 542篇 |
出版年
2024年 | 6篇 |
2023年 | 15篇 |
2022年 | 97篇 |
2021年 | 116篇 |
2020年 | 97篇 |
2019年 | 115篇 |
2018年 | 97篇 |
2017年 | 103篇 |
2016年 | 122篇 |
2015年 | 117篇 |
2014年 | 124篇 |
2013年 | 155篇 |
2012年 | 155篇 |
2011年 | 148篇 |
2010年 | 116篇 |
2009年 | 119篇 |
2008年 | 89篇 |
2007年 | 144篇 |
2006年 | 139篇 |
2005年 | 133篇 |
2004年 | 74篇 |
2003年 | 92篇 |
2002年 | 64篇 |
2001年 | 47篇 |
2000年 | 48篇 |
1999年 | 64篇 |
1998年 | 45篇 |
1997年 | 49篇 |
1996年 | 54篇 |
1995年 | 25篇 |
1994年 | 33篇 |
1993年 | 22篇 |
1992年 | 18篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
排序方式: 共有2901条查询结果,搜索用时 562 毫秒
991.
Ran Wei Alan T. Murray 《International journal of geographical information science》2013,27(7):1231-1249
There exist many facets of error and uncertainty in digital spatial information. As error or uncertainty will not likely ever be completely eliminated, a better understanding of its impacts is necessary. Spatial analytical approaches, in particular, must somehow address data-quality issues. This can range from evaluating impacts of potential data uncertainty in planning processes that make use of methods to devising methods that explicitly account for error/uncertainty. To date, little has been done to structure methods accounting for error. This article develops an integrated approach to address data uncertainty in spatial optimization. We demonstrate that it is possible to characterize uncertainty impacts by constructing and solving a new multi-objective model that explicitly incorporates facets of data uncertainty. Empirical findings indicate that the proposed approaches can be applied to evaluate the impacts of data uncertainty with statistical confidence, which moves beyond popular practices of simulating errors in data. 相似文献
992.
Majid Esmaelian Francisco J. Santos Arteaga Sommayeh Mohammadi 《International journal of geographical information science》2013,27(7):1187-1213
Earthquakes occurring in urban areas constitute an important concern for emergency management and rescue services. Emergency service location problems may be formulated in discrete space or by restricting the potential location(s) to a specified finite set of points in continuous space. We propose a Multicriteria Spatial Decision Support System to identify shelters and emergency service locations in urban evacuation planning. The proposed system has emerged as an integration of the geographical information systems (GIS) and the multicriteria Decision-Making method of Preference Ranking Organization Method for Enrichment Evaluation IV (PROMETHEE IV). This system incorporates multiple and often conflicting criteria and decision-makers’ preferences into a spatial decision model. We consider three standard structural attributes (i.e., durability density, population density, and oldness density) in the form of spatial maps to determine the zones most vulnerable to an earthquake. The information on these spatial maps is then entered into the ArcGIS software to define the relevant scores for each point with regards to the aforementioned attributes. These scores will be used to compute the preference functions in PROMETHEE IV, whose net flow outranking for each alternative will be inputted in ArcGIS to determine the zones that are most vulnerable to an earthquake. The final scores obtained are integrated into a mathematical programming model designed to find the most suitable locations for the construction of emergency service stations. We demonstrate the applicability of the proposed method and the efficacy of the procedures and algorithms in an earthquake emergency service station planning case study in the city of Tehran. 相似文献
993.
cand.phil KRISTEN FREDRIK STRAY 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):42-48
Stray, Kristen Fredrik: Små og mellomstore industribedrifter i Oslo indre by. Problemer, konflikter og tiltak i byfornyelsen. Geografisk Tidsskrift 83: 42–48, May 1., 1983. In 1977 the City Council of Oslo passed an act of city renewal. 18 renewal districts in the inner part of Oslo were chosen. These areas with houses and housing facilities of low quality consist of a mixture of dwellings and economic activities of industry and trade. This paper deals with the problems and conflicts one meets when bringing through a renewal programme of housing and environmental improvements that cause restrictions to future economic activities or force firms to move out. 相似文献
994.
Grant Ian Thrall 《The Professional geographer》2013,65(3):446-447
This study seeks to examine the relationship between childhood exposure to air pollution and long-term respiratory health and to identify significant predictors of respiratory health in adulthood. Logistic regression modeling was undertaken using health and exposure data for 395 participants who resided during childhood in four distinct neighborhoods in Hamilton, Ontario, Canada. Significant predictors include exposure to SO2 in childhood, location of residence in childhood, sex, residential and occupational histories, stressful life events, and respiratory health in childhood. This study suggests that the health impacts of childhood exposure to air pollution are located beyond the short-term period that most research addresses. 相似文献
995.
《The Professional geographer》2013,65(1):67-82
This article demonstrates the operation of a simple optimal location-allocation technique for solving the problem of locating one or several community recycling center(s) within a residential area. The article attempts to measure both transportation and externality costs in comparable units, and to incorporate them into the model. A sensitivity analysis of the results at the level of the nuisance provides further insight into the operation of the model and the relative importance of the quantification of pollution in applied location-allocation problems. 相似文献
996.
《The Professional geographer》2013,65(4):488-489
Book Reviewed in this article: Main Street: Northeastern Oregon: The Founding and Development of Small Towns. Barbara Ruth Bailey. Food Politics: The Regional Conflict. David N. Balaam and Michael J. Carey, eds. The International Economy and Industrial Development: Trade and Investment in the Third World. R. Ballance, J. Ansari and H. Singer. Neighborhoods in Urban America. Ronald H. Bayor, ed. The English Heartland. By Robert Beckinsale and Monica Beckinsale. Regional Dimensions of Industrial Policy. Michael E. Bell and Paul S. Lande, eds. Tension Areas of the World. D. Gordon Bennett, ed. Latin America: an Introductory Survey. B. W. Blouet and O. M. Blouet, eds. Integration and Division: Geographical Perspectives on the Northern Ireland Problem. Frederick W. Boal and J. Neville H. Douglas, eds. Energy and Land Use. Robert W. Burchell and David Listokin, eds. Slopes and Weathering. Michael Clarke and John Small. Alaska's Rural Development. Peter G. Cornwall and Gerald McBeath, eds. The Politics of Park Design: A History of Urban Parks in America. Galen Cranz. World Congress on Land Policy, 1980, Proceedings. Matthew Cullen and Sharon Woolery, eds. Oregon Divided: A Regional Geography. Samuel N. Dicken and Emily F. Dicken. Urban Food Marketing and Third World Rural Development. T. Scarlett Epstein. South Africa: Spatial Frameworks for Development. T. J. D. Fair. Institutions and Geographical Patterns. Robin Flowerdew, ed. Industrialization of U.S. Agriculture, An Interpretive Atlas. Howard F. Gregor. Planning Theory: Prospects for the 1980s. Patsy Healy, Glen McDougall and Michael J. Thomas, eds. Neighborhood Mobilization: Redevelopment and Response. Jeffrey R. Henig. The American Urban System: A Geographical Perspective. R. J. Johnston. Climate, History and the Modern World. Hubert H. Lamb. Climate and History: Studies in Past Climates and Their Impact on Man. T. M. L. Wigley, M. J. Ingram and G. Farmer. China: Railways and Agricultural Development, 1875–1935. Ernest P. Liang. A Desirable Energy Future—A National Perspective. Robert S. Livingston, T. D. Anderson, T. M. Besmann, M. Olszewski, A. M. Perry, and C. D. West. Topothesia: Essays Presented to T. S. Ó Máille. B. S. Mac Aodha, ed. Transportation for the Poor: Research in Rural Mobility. Hal S. Maggied. Land Uses in American Cities. Harold M. Mayer and Charles R. Haves. Industrial Organisation and Location. Philip McDermott and Michael Taylor. Human Adaptability: an Introduction to Ecological Anthropology. Emilio F. Moran. Regional Analysis and the New International Division of Labor. Frank Moulaert and Patricia W. Salinas, eds. The Nuclear War Atlas. Victoriaville, Quebec, Canada: Urbanization and Environmental Quality. Isao Orishimo. The Garden of Eden: The Botanic Garden and the Re-Creation of Paradise. John Prest. Earthfire, The Eruption of Mount St. Helens. Charles Rosenfeld and Robert Cooke. Contest for the South China Sea. Marwyn S. Samuels. The Future of the Wetlands: Assessing Visual-Cultural Values. Richard C. Smardon, ed. Tucson: the Life and Times of An American City. C. L. Sonnichsen. The Geography of Multinationals. Michael Taylor and Nigel Thrift, eds. Impact of Marine Pollution on Society. Virginia Tippie and Dana Kester. Reviving the Industrial City: the Politics of Urban Renewal in Lyon and Birmingham. Jerry A. Webman. Andean Reflections: Letters from Carl O. Sauer While on a South American Trip under a Grant from the Rockefeller Foundation, 1942. Robert C. West, ed. Cartographic Drawing with Computers. P. Yoeli. 相似文献
997.
赣南大富足花岗岩体西部铀成矿条件及找矿前景 总被引:1,自引:0,他引:1
赣南大富足花岗岩体位于南岭构造带北部,与武夷山构造带南段交汇处,为印支-燕山期复式花岗岩岩体。岩体西部的河草坑铀矿田是中国重要的铀矿田之一。大富足花岗岩基由小富足、上寮、赤泥、富城、草桃背5个岩体组成,均为富硅、贫铁镁、铝过饱和的钙碱性花岗岩,具有较高的铀背景值。岩体西部边缘有一长10 km、宽1 km的紫色蚀变带,其下为绿色蚀变带,铀矿体赋存于紫色带底部与绿色带界面上下。铀矿经过了花岗岩成矿阶段、火山岩成矿阶段和淋积叠加成矿阶段。文章通过分析基底地层、岩体特征、构造、区域蚀变及铀矿化控制因素等,总结了该区"铀源丰富、热源充足、构造发育、蚀变强烈、剥蚀适中"等5个有利铀成矿条件,在此基础上确定半岭及大坪山2处为最有远景的地段,分别位于岩体西部火山机构附近铀矿隐伏区及北部地堑区。 相似文献
998.
西天山吐拉苏盆地安山岩中发现岩石包体及地质找矿意义 总被引:4,自引:0,他引:4
新疆西天山斑岩型铜矿找矿前景良好,但面临攻坚;吐拉苏盆地是西天山浅成低温热液型金矿集区,晚古生代吐拉苏盆地是北天山洋向南向伊犁板块之下俯冲形成的“西南太平洋型”岛弧环境,在金矿深边部寻找斑岩型铜金矿值得关注。笔者最近在岛弧安山岩中发现硫化物矿化二长斑岩、细晶闪长岩等岩石包体。岩石包体发现于塔乌尔别克金矿区,多呈浑圆体或次棱角状,随机分布于安山岩中,与围岩界线截然,常见安山岩围绕岩石包体形成冷凝边。二长斑岩包体显示似斑状结构,斑晶由斜长石和钾长石组成;细晶闪长岩主要由斜长石和角闪石组成,细晶结构,块状构造;寄主安山岩为斑状结构,斑晶为斜长石和少量角闪石及单斜辉石,基质由短柱状斜长石及少量单斜辉石组成,玻基交织结构。二长斑岩包体、细晶闪长岩包体和寄主安山岩三者具有极为相似的微量元素和稀土元素组成,均富集大离子亲石元素、相对亏损Nb、Ta等高场强元素。这些岩石学和地球化学特点反映岩石包体是岛弧火山喷发过程中从下覆地质体捕掳成因,指示安山岩层之下存在同源斑岩体并可能已发生硫化物矿化。综合考虑吐拉苏盆地铜矿化点、酸性热液蚀变、高硫型和低硫型浅成低温热液金矿的组合关系,认为盆地内发育斑岩-浅成低温热液金铜成矿系统,塔乌尔别克是斑岩型铜金矿找矿重要靶区。 相似文献
999.
湖南锡田锡钨多金属矿床成矿构造特征及其找矿意义 总被引:4,自引:0,他引:4
锡田矿床内发育近SN向花岗岩穹窿伸展构造、NE向复式褶皱和NE或NEE向走滑伸展构造系统。穹窿构造主要由印支期和燕山期侵入的花岗岩和古生代地层及不连续的环形滑脱断层组成,控制燕山期花岗岩与围岩接触带矽卡岩型矿体的分布;复式褶皱为古生代地层组成的NE向复式向斜,在矿区中部被锡田复式花岗岩体切割。严塘复式向斜与小田复式向斜中的背斜核部,尤其断层叠加的部位常控制一些构造破碎带型钨锡富矿体的分布。NE向或NEE向走滑伸展构造系统包括NE向右行(伸展)走滑断层、NE向或近EW向右行次级的走滑伸展断层、近SN向左行走滑断层和NW向伸展断层,控制了锡田矿区内的不同方向构造蚀变岩型、石英脉型和云英岩脉型锡钨多金属矿床的分布。花岗岩锆石U-Pb、白云母40Ar-39Ar和辉钼矿Re-Os同位素测年表明锡田地区燕山期构造活动、岩浆作用与成矿响应时间非常接近,介于150~160Ma。岩体与地层(灰岩)接触带、岩体中的NEE向断裂带以及被NE向断裂叠加的背斜轴部是重要的成矿区域,可作为下一步矿产勘查工作重要靶区。 相似文献
1000.