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   2374篇
  免费   68篇
  国内免费   85篇
测绘学   193篇
大气科学   18篇
地球物理   57篇
地质学   316篇
海洋学   55篇
天文学   20篇
综合类   59篇
自然地理   1809篇
  2024年   1篇
  2023年   20篇
  2022年   86篇
  2021年   71篇
  2020年   96篇
  2019年   102篇
  2018年   107篇
  2017年   109篇
  2016年   95篇
  2015年   79篇
  2014年   85篇
  2013年   239篇
  2012年   197篇
  2011年   79篇
  2010年   51篇
  2009年   81篇
  2008年   77篇
  2007年   93篇
  2006年   95篇
  2005年   80篇
  2004年   78篇
  2003年   74篇
  2002年   72篇
  2001年   41篇
  2000年   58篇
  1999年   67篇
  1998年   46篇
  1997年   28篇
  1996年   22篇
  1995年   25篇
  1994年   26篇
  1993年   21篇
  1992年   20篇
  1991年   15篇
  1990年   7篇
  1989年   10篇
  1988年   18篇
  1987年   11篇
  1986年   16篇
  1985年   8篇
  1984年   7篇
  1983年   10篇
  1982年   2篇
  1979年   1篇
  1978年   1篇
排序方式: 共有2527条查询结果,搜索用时 15 毫秒
1.
The open-ended corporate interview as a qualitative research method is proposed as a valuable component of an evidentiary strategy in economic geography. It is argued to be more sensitive than other survey methods to historical, institutional, and strategic complexity. The corporate interview method is particularly appropriate in periods of economic and social change that challenge traditional analytical categories and theoretical principles. Some problems inherent to the method, and strategies for minimizing their impact on the research project, are described.  相似文献   
2.
3.
This paper considers the present state of mathematical geology. Three directions are recognized: applied, theoretical, and mathematical. Applied mathematical geology includes formal use of mathematics to solve problems and computer processing of data. Success is achieved by a correspondence of mathematical methods used to the nature of geological data. This correspondence can be demonstrated by purely mathematical means. Theoretical mathematical geology uses mathematics as a language of geology; however, a number of methodological problems must be solved: formalization of initial geological concepts and creation of a strict conceptual basis, substantiation of initial principles of mathematical simulation, creation of theoretical geological models, problems of elementary and coincidence in geology, and methodological substantiations of possibilities of any mathematical model to approximate geological models. The essense and significance of these problems are considered. The main task of mathematical geology is to prove its correspondence to the nature of the geological objects studied, geological data obtained, and geological problems solvable. Finally, the main problems of mathematical geology are not so much mathematical as geological and methodological.  相似文献   
4.
Federico Caprotti 《Geoforum》2008,39(2):942-957
This paper investigates the Italian fascist regime’s use of internal colonisation as part of a wider ruralisation policy aimed at promoting population growth, curbing rural-urban migration, staunching emigration, and halting the spread of industrial urbanisation. By focusing on the case study of the Pontine Marshes, the paper demonstrates how, through targeted selection procedures aimed at displacing defined social and political undesirables, migrants were chosen and effectively coerced into migrating to the “fascist” landscape of the marshes. The area, reclaimed and developed in the 1930s, was celebrated as a sign of the regime’s engineering and social success. The paper utilises Antonio Gramsci’s thought on hegemony, and argues that the overt use of coercion hints at the fact that fascism, although ideologically totalitarian and hegemonic, was contested. Although statisticians, demographers and state bureaucrats were organised and institutionalised in the construction of hegemony based on consent, fascism based itself more in coercion than in passive consent in the case of internal colonisation.  相似文献   
5.
In respect of an offshore berthing pillar, the test study result of current force acting on mooring ships is described in this paper. Empirical and semi-empirical relationships of current force coefficient are given according to the angle between the flow direction and the ship's longitudinal axis, which are coincident with the result of theoretical analysis.  相似文献   
6.
根据作者导得的AfKdV方程,理论上确定了先锋孤立子生成问题的理论平均波阻,能量劈分及能量劈分比。本文的能量劈分是确定先锋孤立子生成参数的理论基础。同时,本理论确定了现有理论中的自由未知参数问题,从而使先锋孤立子生成参数得到理论预报。  相似文献   
7.
8.
9.
提出了一种基于移动测量系统技术的"真图"数据解决方案。一方面极大地丰富了GIS数据源,另一方面通过相应的真图影像数据管理软件及开发包扩展GIS功能,为各行业应用提供了地理信息数据解决方案。  相似文献   
10.
鞠继武 《地理研究》1994,13(1):100-103
本文阐述我国清代中期思想家、地理学家魏源的思想及共《海国图志》的特点及历史意义。  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