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   3157篇
  免费   137篇
  国内免费   574篇
测绘学   403篇
大气科学   13篇
地球物理   73篇
地质学   1172篇
海洋学   133篇
天文学   1篇
综合类   100篇
自然地理   1973篇
  2024年   5篇
  2023年   25篇
  2022年   111篇
  2021年   101篇
  2020年   134篇
  2019年   140篇
  2018年   132篇
  2017年   158篇
  2016年   153篇
  2015年   155篇
  2014年   155篇
  2013年   347篇
  2012年   282篇
  2011年   165篇
  2010年   121篇
  2009年   152篇
  2008年   154篇
  2007年   175篇
  2006年   183篇
  2005年   163篇
  2004年   141篇
  2003年   98篇
  2002年   93篇
  2001年   68篇
  2000年   77篇
  1999年   67篇
  1998年   57篇
  1997年   37篇
  1996年   25篇
  1995年   29篇
  1994年   25篇
  1993年   13篇
  1992年   19篇
  1991年   14篇
  1990年   10篇
  1989年   11篇
  1988年   16篇
  1987年   11篇
  1986年   16篇
  1985年   9篇
  1984年   8篇
  1983年   10篇
  1982年   3篇
排序方式: 共有3868条查询结果,搜索用时 215 毫秒
931.
The intent of this paper is to explore how ‘reel’ and ‘real’ landscapes can be rendered dialectic. The analysis focuses on the filming of Tarzan's Secret Treasure (1941) at the wildlife preserve of Wakulla Springs in Florida, which was administered by the financial tycoon Ed Ball. Using Mitchell's recent commentaries on ‘good’ and ‘bad’ dialectics as our entry point, we offer two readings of this cinematic process. The first renders the on and off screen Wakulla Springs as ideological fodder, serving to valorise capital, masculinity and whiteness. The second reading addresses how this place has been actively constructed from discourses pertaining to class, gender and race, such that Wakulla exists as a series of fully relational spaces within diverse contexts, both ‘real’ and ‘reel’. In structuring our analysis in this manner, we hope to make clear why it does indeed matter for film geographers to acknowledge the conceptual presumptions brought to bear in the framing of the real and the reel as objects of analysis. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
932.
王张华  陈杰 《第四纪研究》2004,24(4):537-545
文章通过对长江三角洲南北两岸太湖和里下河两大平原新石器遗址分布和迁移特征的对比研究,发现两地新石器文化均起源于7000aB.P.前。可以认为全新世气候变暖和海平面上升是两地新石器文化兴起的原因。之后里下河平原经历了由全新世海侵引起的盐沼化过程,古文化发展受到明显的抑制;相比之下,太湖古平原为一丘状台地,地势高爽,加上贝壳砂堤对海水的有效阻挡,盐沼化过程稍弱,古文化得以延续和繁荣。  相似文献   
933.
This research analyzes the geographic patterns of domestic air passenger transport in China from 1980 to 1998, with three foci: (1) impacts of economic reforms, (2) regional inequality in air transport development, and (3) network development. Accessibility to air transport improved significantly as China expanded its air transport system, 1980–1998. The dominance of major airports declined as the air transport system expanded to medium and small cities. The centroid of passenger volume migrated toward southeast, consistent with the expansion of economic growth in southeast coastal areas. The rule of distance decay in air traffic was more applicable to China in 1998 than in 1985 as the market economy worked its way into China's air transport system. The East Region had a much higher share of air passengers than its share of population and GDP, followed by the West and the Middle Regions, reflecting an interesting “flyover” effect. By 1998, a hub‐and‐spoke air transport system was clearly in place in China.  相似文献   
934.
Geographers at the AAG's centennial are challenged with exceptional opportunities to create a more central place for geography in society and in the university. Realizing these opportunities requires identifying and leveraging key emerging trends in the formation and uses of geographic knowledge. Better integration of geography's profound technological innovations with its core traditions also is necessary to strengthen the discipline's research capacity, and to more effectively engage with and contribute to the needs of society. Trends toward multidisciplinary research and integrative science, and the heightened need for geographic understanding in today's world, hold further promise for advancing the discipline while sustaining its historic strengths and diversity.  相似文献   
935.
This article examines trends over the past five decades in three human resource issues in geography: the production of new geographers; the size and diversity of the membership of the Association of American Geographers (AAG); and the topical specializations of geographers. The number of geography degrees awarded increased rapidly in the 1950s and 1960s, followed by a modest decline as baby boomers exited their college years. The number surged again in the 1990s, however, and it seems to have stabilized in recent years. AAG membership trends followed a similar trajectory and membership is currently poised to set a new record. The participation of women in the discipline has increased steadily over the past half‐century, but geography still lags the social and physical sciences in the share of women receiving bachelor's degrees. The participation of geographers from ethnic minority groups continues to be very low. The number of AAG specialty groups has doubled since their inception in 1978, and geographic information science (GIS) now occupies a prominent position within the discipline. Challenges in the coming years include increasing the diversity in geography, reducing the turnover in AAG membership, preparing for the imminent retirement of a large cohort of baby‐boom geographers, and reconnecting with nonacademic geographers.  相似文献   
936.
Human geography today exhibits unprecedented vitality and diversity. This survey first charts some major lines of research in the field in light of the ascendancy of critical theory, political economy, and poststructuralist thought, including feminism, the cultural turn, consumption, urban geography, and globalization. Next, it focuses on several “cutting‐edge” issues, such as race, postcolonialism, the social construction of nature, representations of space, and cyberspace. Finally, the article turns an eye toward the future, offering comments on the discipline's likely trajectories with regard to the blurring of traditional dualisms, methodological integration, and the lacunae of public policy and geographic education.  相似文献   
937.
The production and use of fossil fuels and nonrenewable electricity creates many forms of environmental degradation. To reduce degradation, this research suggests an energy strategy based on energy end‐use analysis and regional geography. Energy end‐use analysis and regional geography are used to match renewable energy resources with site‐specific, end‐use needs. Fieldwork conducted within Centre County, Pennsylvania, demonstrates that small‐scale solar, wind, and micro‐hydropower resources could displace a proportion of household electricity use. Such an approach meets energy end‐use needs, while conserving fossil fuels and reducing environmental degradation.  相似文献   
938.
从区域旅游发展的角度,对大型山岳旅游地的空间规划与设计案例国内外不乏枚举,但都是从研究对象中进行具象剖析,还没有系统地对某一山岳风景旅游地进行既全面又具体的方法论及其依据理念的总结。本文以江西上饶三清山风景名胜旅游地为例,对涉及旅游空间规划与设计的基础内容进行剖析,力图总结出大型山岳风景旅游地规划与设计系统的空间分析方法及模式。主要空间规划与设计内容与方法:①三清山旅游资源、旅游地景观结构、形象设计;②三清山旅游区旅游规划与设计的基础理念;③三清山旅游区旅游空间规划与设计;④实现三清山旅游区规划布局的空间手段。  相似文献   
939.
Louise Bracken  Emma Mawdsley 《Area》2004,36(3):280-286
Fieldwork in geography has come under close scrutiny from feminist and postcolonial scholars in recent years. In relation to physical geography, commentators have pointed to a range of practices and images (notably the 'heroic', masculinist 'ideal') that have acted to deter and exclude women, from undergraduates to senior academics. For some, fieldwork is one of the key sites of gender discrimination for women in physical geography. This paper starts from a position of agreement with many of these critiques, but also seeks to 'reclaim' some more positive accounts and perspectives on the subject. In doing so, it aims to critique and disrupt the dominant image of physical geography fieldwork as essentially a masculinist endeavour, and encourage a wider view of the challenges and pleasures of fieldwork for women in physical geography.  相似文献   
940.
大型有限元软件ANSYS在堆山工程中的应用   总被引:1,自引:0,他引:1  
建筑垃圾堆山造景是生态城市建设中的一个新课题,是有效处理及利用建筑垃圾的新方法,然而地基基础沉降和山体稳定性是建筑垃圾堆山造景中山体设计的关键.现利用大型有限元通用软件ANSYS对山体在自重载荷作用下的沉降和稳定性进行实体模型仿真计算,并与工程常用简化计算进行比较,两者结果基本一致.并在有限元计算中,利用ANSYS有限元软件中的参数化设计语言(APDL)编制了山体塑性判别程序,进而对山体堆填过程的沉降和稳定性有一个整体的了解,这对山体的施工有巨大的指导意义.这将为类似工程山体设计和施工控制提供有效依据.  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