首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   263篇
  免费   40篇
  国内免费   16篇
测绘学   15篇
大气科学   11篇
地球物理   104篇
地质学   73篇
海洋学   11篇
天文学   6篇
综合类   12篇
自然地理   87篇
  2023年   1篇
  2022年   2篇
  2021年   6篇
  2020年   8篇
  2019年   12篇
  2018年   3篇
  2017年   14篇
  2016年   9篇
  2015年   10篇
  2014年   9篇
  2013年   17篇
  2012年   13篇
  2011年   12篇
  2010年   12篇
  2009年   20篇
  2008年   12篇
  2007年   23篇
  2006年   13篇
  2005年   11篇
  2004年   10篇
  2003年   8篇
  2002年   7篇
  2001年   17篇
  2000年   9篇
  1999年   8篇
  1998年   4篇
  1997年   2篇
  1996年   5篇
  1995年   5篇
  1994年   4篇
  1993年   4篇
  1992年   1篇
  1991年   4篇
  1990年   5篇
  1989年   5篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
  1978年   1篇
排序方式: 共有319条查询结果,搜索用时 31 毫秒
31.
于希贤 《地理学报》1989,44(2):246-252
本文回顾了400年来对徐霞客及其游记研究的五个阶段:近代启蒙地理学探索;对散失游记重新搜集整理;用近代的理论与方法进行研究;放到资本主义经济萌芽背景上进行研究;近年来全面综合的研究。评价了各阶段主要研究者的重要贡献。展望了今后开拓的新领域,再现当时的地理环境,找出其中演化趋势;并阐述了发掘徐霞客精神的重要意义。  相似文献   
32.
BOOK REVIEWS     
Books reviewed in this article: Aerial Photography and Remote Sensing. Terrain Analysis and Remote Sensing . JOHN R. G. TOWNSHEND , ed. Environmental Data Use in Computer-assisted Data Handling Systems: The Results of a Survey of Applications in the Pacific Northwest States . KENNETH E. GORDON . Applied Land Use: A Spatial Approach . JOHN F. LOUNSBURY , LAWRENCE M. SOMMERS , AND EDWARD A. FERNALD , eds. The Second Battle of New Orleans: A History of the Vieux Carre Riverfront-Expressway Controversy . RICHARD O. BAUMBACH , JR. AND WILLIAM E. BORAH . Cultural Environmental Archaeology . MYRA SHACKLEY . The Immoral landscape: Female Prostitution in Western Societies . RICHARD SYMANSKI . life Among the Poor in Cairo . UNNI WIKAN , translated by Ann Henning. Women, Work and Property in Northwest India . URSULA SHARMA . The Domestication of Women: Discrimination in Developing Societies . BARBARA ROGERS Economic Optimization in Locational and Transport Analysis . A. G. WILSON , J. D. COELHO , S. M. MACGILL , H. C. W. L. WILLIAMS . New Tools for Economic Development: The Enterprise Zone, Development Bank, and RFC . GEORGE STERNLIEB AND DAVID LISTOKIN , eds. Regional Wage Inflation . R. L. MARTIN , ed. Finding A Place For Energy-Siting Coal Conversion Facilities . FRANK J. CALZONETTI WITH MARK S. ECKERT . Environmental Management, Resources, and Systems Environmentalism. Second Edition . T. O'RIORDAN . Countryside Conservation . BRYN GREEN . Medical Spatial Diffusion: An Historical Geography of Epidemics in an Island Community . A. D. CLIFF , P. HAGGETT , J. K. ORD , AND G. R. VERSEY . Philosophy and Geographic Thought Order and Skepticism: Human Geography and the Dialectic of Science . RICHARD SZYMANSKI AND JOHN A. AGNEW . Measurement of Subjective Phenomena . D. F. JOHNSTON , ed. Conceptions of Space in Social Thought: A Geographic Perspective . ROBERT DAVID SACK . The Association of American Geographers: The First Seventy-five Years: 1904-1979 . PRESTON E. JAMES AND GEOFFREY J. MARTIN . The Life and Thought of Isaiah Bowman . GEOFFREY J. MARTIN . Physical River Basin Planning: Theory and Practice . SURANJIT K. SAHA AND CHRISTOPHER J. BARROW , eds. Soils and landforms: An Integration of Ceomorphology and Pedology . A. I. GERRARD Climatic Change and Society. Consequences of Increasing Atmospheric Carbon Dioxide . WILLIAM W. KELLOGG AND ROBERT SCHWARE . Political Political Redistrictings and Geographic Theory . RICHARD L. MORRILL . Population Studies in Spanish American Population History: Dell Plain Latin American Studies NO. 8 . DAVID J. ROBINSON , ed. Population Redistribution in the Midwest . CURTIS C. ROSEMAN , ANDREW J. SOFRANKO , AND JAMES D. WILLIAMS , eds. Geographical Perspectives on the Elderly . A. M. WARNES , ed. Regional Perspective On the American South . MERLE BLACK AND JOHN SHELTON REED , eds. The Prairies and Plains: Prospects for the 80s . JOHN R. ROGGE , ed. Rural Rural Settlement in an Urban World . MICHAEL BUNCE . Social Accident at Three Mile Island: The Human Dimensions . DAVID L. SILLS , C. P. WOLF , AND VIVIEN B. SHELANSKI , eds. The American Small Town: Twentieth-Century Place Images . JOHN JAKLE . Urban A House of My Own . SUSAN LOBO . The City: Patterns and Processes in the Urban Ecosystem . CHRISTOPHER H. EXLINE , GARY L. PETERS , AND ROBERT P. LARKIN . Movement in Cities . P. W. DANIELS AND A. M. WARNES . Urbanization and Urban Planning in Capitalist Society . MICHAEL DEAR AND ALLEN J. SCOT , eds.  相似文献   
33.
《The Journal of geography》2012,111(3):111-117
Abstract

The United States is undergoing rapid demographic change leading to growing racial, ethnic, religious and economic diversity in our classrooms. Our students can be sensitized to this growing diversity through exposure to the concept of social justice. The purpose of this article is to provide examples of how social justice issues can be included in classroom discussions of the American system of political representation. For this purpose, it examines selected aspects of the redistricting process. It points out that our historic reliance upon the winner-take-all single-member district system of electing representatives to legislative bodies limits the opportunity for minority groups to be fairly represented. It also provides an overview of the impact of the criminal justice system upon fair political representation. The article concludes with an example of a classroom exercise to demonstrate its major points.  相似文献   
34.
Humans constitute one of the main geomorphological agents in modern times. As an example, post-mining regions represent a typical landscape of the Anthropocene. Strong relief modifications are particularly obvious with open pit mining. However, many existing mining areas are lacking detailed pre-mining information for the quantification of anthropogenic relief changes, which is a considerable challenge in regions with historic mining activities. Here, the Ville (Rhenish lignite district, Germany) is used to quantify surface mining induced relief changes in one of the oldest and currently largest lignite districts in Europe. Historical maps from first geodetic mapping in 1893 enabled construction of a historic digital elevation model to quantify the relief changes in comparison to elevation data from 2000 and 2015. The vertical accuracy of the historic data is remarkably high, with relief differences < 2 m in areas not affected by mining. In total, 49.2% of the investigated area (184 km2) shows a relief deficit and 14.5% has positive relief differences. Absolute changes account for more than 80 m heightening (dumpsites of overburden) and lowering of the natural relief (pits). Besides these altitudinal changes, overall steeper slopes are significant for the new topography, but levelling exists likewise. The spatial variabilities are discussed in the context of the regional geology and the mining techniques. Undoubtedly, such large-scale anthropogenic relief changes persist for a very long time and will last as a human legacy far into the future. Only the detailed reconstruction of the pre-mining relief offers the ability to clarify the dimension of humans as geomorphological agents and to understand landscape perception. Due to the fact that the impact of open pit mining has such a large vertical and horizontal extension, their consideration as part of anthropogeomorphology can significantly contribute to support future Critical Zone research in the Anthropocene.  相似文献   
35.
砾钢渣抗液化特性试验研究   总被引:1,自引:0,他引:1  
陈化的钢渣作为土工回填材料是废弃钢渣循环利用的主要途径之一。按土的工程分类方法,将废弃钢渣划分为砾钢渣、粗钢渣和细钢渣。针对砾钢渣,考虑固结应力比、振动频率、围压和含砾量等影响因素开展动三轴试验研究。分析了砾钢渣的应力、应变和动孔隙水压力的特性,分析了砾钢渣试样的动强度与振动次数、动应变与振动次数、孔隙水压力与振动次数和动应力与动应变关系。采用Seed和Finn提出的饱和砂土动孔压计算模型分析砾钢渣的动孔压曲线类型,并与传统砂砾土的抗液化强度进行比较。得出砾钢渣的抗液化特性较好,工程中可以用砾钢渣替代传统的砂土、砂砾土、砂砾料和砂卵石作为回填料,解决砂砾资源日渐短缺的问题。  相似文献   
36.
Determining mean transit times in headwater catchments is critical for understanding catchment functioning and understanding their responses to changes in landuse or climate. Determining whether mean transit times (MTTs) correlate with drainage density, slope angle, area, or land cover permits a better understanding of the controls on water flow through catchments and allows first-order predictions of MTTs in other catchments to be made. This study assesses whether there are identifiable controls on MTTs determined using 3H in headwater catchments of southeast Australia. Despite MTTs at baseflow varying from a few years to >100 years, it was difficult to predict MTTs using single or groups of readily-measured catchment attributes. The lack of readily-identifiable correlations hampers the prediction of MTTs in adjacent catchments even where these have similar geology, land use, and topography. The long MTTs of the Australian headwater catchments are probably in part due to the catchments having high storage volumes in deeply-weathered regolith, combined with low recharge rates due to high evapotranspiration. However, the difficulty in estimating storage volumes at the catchment scale hampers the use of this parameter to estimate MTTs. The runoff coefficient (the fraction of rainfall exported via the stream) is probably also controlled by evapotranspiration and recharge rates. Correlations between the runoff coefficient and MTTs in individual catchments allow predictions of MTTs in nearby catchments to be made. MTTs are shorter in high rainfall periods as the catchments wet up and shallow water stores are mobilized. Despite the contribution of younger water, the major ion geochemistry in individual catchments commonly does not correlate with MTTs, probably reflecting heterogeneous reactions and varying degrees of evapotranspiration. Documenting MTTs in catchments with high storage volumes and/or low recharge rates elsewhere is important for understanding MTTs in diverse environments.  相似文献   
37.
旅游开发已成为近年来城市历史街区复兴的主要方式之一,但盲目的旅游开发易给街区内的文化遗产造成无法弥补的损失,有必要对其社会-生态环境与旅游开发耦合协调程度进行分析。构建适应城市历史街区发展需要的社会-生态环境与旅游开发耦合协调模型,运用熵值法计算各指标的权重,以南京市8个重点历史街区为例进行实证分析。结果表明:南京历史街区的社会-生态环境与其旅游开发的耦合协调程度总体呈现失调态势,同时证实了模型的可操作性及其在历史街区旅游发展背景下的指导价值。  相似文献   
38.
黄河干流浮游植物群落特征及其对水质的指示作用   总被引:1,自引:0,他引:1  
2008年5-6月和9-10月对黄河干流13个河段和4座水库的浮游植物群落及其环境进行了全面调查.共鉴定浮游植物8门83属150种,其中有硅藻59种,绿藻55种,蓝藻24种,甲藻4种,裸藻4种,金藻2种,黄藻1种和隐藻1种,平均细胞密度和生物量分别为126.90×104cells/L和0.940mg/L.从大的格局上看,浮游植物群落在种类数、种类组成和现存量上均存在较明显的空间分异,这种分异性可从河流流速、泥沙含量和受污染程度得到解释.根据浮游植物污染指示种和Shannon-Wiener多样性指数分析,黄河干流各河段多受到不同程度的污染.与1986年的资料相比,黄河干流浮游植物组成发生了明显变化,属数下降了9.8%,而平均生物量升高了128.7%,且在种类组成上也发生了明显的变化,表明河流污染程度的加剧.  相似文献   
39.
历史村镇的旅游商业化控制研究   总被引:4,自引:2,他引:2  
保继刚  林敏慧 《地理学报》2014,69(2):268-277
在实地调查西递主要街道沿街门面的基础上,通过历时性研究,对比2003 年、2008 年及2009 年的数据,发现西递的旅游商业化已经得到有效的控制。运用质性研究方法,通过对地方政府、村委会(旅游公司)、管理人员、当地村民、店铺业主及游客等的深度访谈,追溯其旅游商业化控制过程中各利益相关者的态度以及博弈过程,总结出历史村镇旅游商业化控制的内在逻辑。最后揭示地方政府预见性的干预是历史村镇旅游商业化得到有效控制的决定性力量。在历史村镇旅游发展的利益相关者中,政府最有能力也最有动力对旅游商业化进行有效的控制。  相似文献   
40.
对中国地震预报现状与未来的思考   总被引:4,自引:2,他引:2  
本文是作者根据自己多年从事地震预报的经历与实践,将我国地震预报的38年历史分为四个阶段,概括了我国地震预报的主要进展和成就,指出地震预报的难点及我国地震预报的思路和技术上存在的几个问题,最后对我国地震预报发展战略提出思考。作者的观点和建议可供地震主管部门的领导和地震分析预报人员参考  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号