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   2839篇
  免费   124篇
  2020年   36篇
  2019年   42篇
  2018年   74篇
  2017年   76篇
  2016年   73篇
  2015年   48篇
  2014年   60篇
  2013年   994篇
  2012年   74篇
  2011年   71篇
  2010年   67篇
  2009年   64篇
  2008年   60篇
  2007年   52篇
  2006年   52篇
  2005年   29篇
  2004年   46篇
  2003年   43篇
  2002年   27篇
  2001年   27篇
  2000年   24篇
  1999年   25篇
  1998年   21篇
  1997年   22篇
  1995年   25篇
  1994年   27篇
  1993年   20篇
  1992年   23篇
  1990年   20篇
  1989年   24篇
  1988年   19篇
  1987年   23篇
  1986年   24篇
  1985年   27篇
  1984年   31篇
  1983年   35篇
  1982年   24篇
  1981年   27篇
  1980年   29篇
  1979年   32篇
  1978年   32篇
  1977年   29篇
  1976年   25篇
  1975年   28篇
  1974年   19篇
  1973年   28篇
  1972年   19篇
  1971年   23篇
  1970年   18篇
  1969年   28篇
排序方式: 共有2963条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
The accumulation of capital is the driving force of the capitalist economy. Various conditions are necessary for accumulation to proceed and each has important spatial aspects. The paper demonstrates that an analysis of these aspects provides a potentially useful framework for understanding the relationship between regional development and economic growth, with particular reference to the Australian experience. Moreover, it is shown that spatial restructuring plays an important role during periods of economic recession in re-establishing the conditions for further growth. This analysis also illuminates some of the limitations of more conventional regional growth theories and debates on convergence versus divergence in regional economic performance.  相似文献   
95.
96.
97.
98.
A recursive model of the spatial allocation of migrants   总被引:1,自引:0,他引:1  
  相似文献   
99.
Fifty-one waster sherds of Terra Sigillata (~20-0 b.c. ) from Arezzo, Italy and Lyons, France have been chemically analysed for twenty-eight elements by neutron activation and seven by X-ray fluorescence. Most of the elemental abundances were measured with high precision and cross-comparisons of the two techniques of measurement (and sample preparation) give added insight as to their relative precision, the calibration differences and the extent to which volatile materials such as carbonate or water influence the results. The sherds from Arezzo formed a homogeneous and distinctive chemical group while all but two of those from Lyons were classified into three such groups. Two of the Lyons groups (MML A and MML B) were from Montée de La Muette and one was from Loyasse. Four additional sherds from houses excavated in Strasbourg and one from Lyons, all of which bore the signature of the famous Anetine pottery-making firm of Ateius, were also analyzed by the same techniques. These signed sherds all had the same composition pattern and it closely matched one of those from Montée de La Muette (MML A) in Lyons. It is therefore suggested that these five sherds bearing the Ateius signature were made in the general vicinity of Lyons and were part of the output of an as yet unknown Gallic branch of the firm of Ateius.  相似文献   
100.
Theoretical values for spacing between points of the Poisson process are frequently used to evaluate the hypothesis that the locations within a region of pointlike objects have a random pattern. These theoretical spacing values are an approximation to spacing values for a uniform process in which the objects are uniformly and independently located in the region. The adequacy of the Poisson approximation to this uniform process for a square region is evaluated by analytic and numeric methods. The approximation is close for a small number of points when spacing between objects is measured by toroidal distance.  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