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   5378篇
  免费   155篇
  2020年   59篇
  2019年   93篇
  2018年   93篇
  2017年   138篇
  2016年   128篇
  2015年   87篇
  2014年   94篇
  2013年   1914篇
  2012年   93篇
  2011年   125篇
  2010年   109篇
  2009年   100篇
  2008年   91篇
  2007年   86篇
  2006年   70篇
  2005年   57篇
  2004年   75篇
  2003年   70篇
  2002年   60篇
  2001年   61篇
  2000年   63篇
  1999年   104篇
  1998年   69篇
  1997年   51篇
  1996年   48篇
  1995年   39篇
  1994年   45篇
  1993年   56篇
  1992年   40篇
  1991年   38篇
  1990年   50篇
  1989年   46篇
  1988年   42篇
  1987年   57篇
  1986年   46篇
  1985年   57篇
  1984年   64篇
  1983年   67篇
  1982年   60篇
  1981年   50篇
  1980年   82篇
  1979年   54篇
  1978年   63篇
  1977年   72篇
  1976年   66篇
  1975年   61篇
  1974年   44篇
  1973年   34篇
  1972年   33篇
  1970年   41篇
排序方式: 共有5533条查询结果,搜索用时 15 毫秒
31.
32.
33.
ABSTRACT. This paper uses a two-stage hedonic wage approach to derive the benefits from improvement of five cultural amenities. It is argued that the hedonic approach permits valuation of both private and local public aspects of cultural goods since access to the amenity is an essential input in the production of the final service flow. Empirical estimates of willingness to pay suggest price and income elasticities are approximately unity. Lower-bound estimates of marginal benefits for a representative city range from $0.85 million for an additional theater to $57.9 million for an additional zoo facility.  相似文献   
34.
ABSTRACT This paper examines the role of the structure of transportation rates in the Weber-Moses triangle model. It shows that, in Zeigler's analysis, the appearance of the price elasticities of demand for inputs actually vanish by a simple application of the envelope theorem. Applying comparative statics analysis, we show when transportation rates are a function of quantity and distance, the assumptions that the production function is homogeneous of degree one and the transportation rates elasticities with respect to quantity and distance are constant are not sufficient to insure that the optimum location is independent of the level of output. This result is significantly different from that obtained by either Miller and Jensen or Zeigler.  相似文献   
35.
The spatial structuring of “classical” central place systems is the primary concern of this research. Emphasizing the development of such systems from basic spatial relations between centers and hinterland locations (rather than as a result of an underlying geometry of regions), this paper takes an optimization approach to the siting of central places in a single-good system. The objective function is shown to be one that maximizes both market coverage of demand and market overlap. Access to this objective is given through the natural slack covering model.  相似文献   
36.
37.
38.
39.
In the past decade Tobler has provided an innovative cartographic presentation of migration flows. The central theme of this research has been to utilize detailed migration data to reveal the underlying structures of migration flows. Even though the analyses are not explanatory models of migration exchanges, the application of these techniques to migration flows over time and across different spatial scales provides a visual generalization of often extremely complex flows. The application of his techniques at two spatial scales for the Netherlands illustrates both the strengths and weaknesses of migration force fields for the analysis of migration.  相似文献   
40.
Spatial compactness has been proposed as a suitable criterion for assessing whether electoral boundaries reflect partisan interests. Although several different measures of spatial compactness have been developed, only limited efforts have been made to compare and evaluate them in the context of electoral redistricting. This paper assesses alternative spatial compactness measures and applies conceptually appealing measures to the provincial ridings proposed by British Columbia's Royal Commission on Electoral Boundaries (1988).  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