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   4670篇
  免费   193篇
  2020年   49篇
  2019年   87篇
  2018年   109篇
  2017年   141篇
  2016年   142篇
  2015年   116篇
  2014年   107篇
  2013年   1741篇
  2012年   113篇
  2011年   128篇
  2010年   121篇
  2009年   126篇
  2008年   85篇
  2007年   143篇
  2006年   114篇
  2005年   57篇
  2004年   62篇
  2003年   55篇
  2002年   64篇
  2001年   48篇
  2000年   48篇
  1999年   45篇
  1998年   54篇
  1997年   57篇
  1996年   29篇
  1995年   44篇
  1994年   29篇
  1993年   32篇
  1992年   35篇
  1991年   24篇
  1990年   30篇
  1989年   27篇
  1988年   37篇
  1987年   43篇
  1986年   32篇
  1985年   48篇
  1984年   50篇
  1983年   50篇
  1982年   52篇
  1981年   47篇
  1980年   47篇
  1979年   48篇
  1978年   45篇
  1977年   46篇
  1976年   39篇
  1975年   38篇
  1974年   15篇
  1973年   27篇
  1972年   25篇
  1971年   16篇
排序方式: 共有4863条查询结果,搜索用时 15 毫秒
71.
72.
Individuals settling new areas have had to rely on a variety of resources, including the social structures inherent in their culture. This study focuses upon the elements of family, kinship and origin in part of nineteenth-century Ontario. It approaches them from the perspectives of interaction over distance and of sociological institution, the particular institution being that of land conveyancing. Data drawn from the surviving parts of the personal and agricultural schedules of the Census of Canada for 1851/52 were searched for the propinquity of individuals to one another. Social interaction seems to have occurred within two miles for most people. Random samples and a series of t-tests suggest that there were no differences in proximity for the members of the different cultural groups but that there were differences between immigrant and established groups with respect to the desires of kin for proximity to one another. These differences were paralleled by differences in the structure of the family. Kinship was also important in determining to whom land was sold; most sales occurred within the particular community. That this was so suggests, according to the model of Steeves, that the level of integration in mid-century Essex was simply embryonic.  相似文献   
73.
Mormons and Jews established agricultural settlements in western Canada around the turn of the century. Mormon colonization was generally successful, characterized by its great stability. Abandonment of the land by Mormon communities was rare. In contrast, almost all the Jewish settlements failed. Settlers abandoned their land and retreated to the urban centres of the West. A comparative analysis of the two groups suggests that this difference in agricultural stability may not have been a reflection of prior experience, nor was it necessarily attributable to vagaries of the physical environment. Social structures, religious demands, and institutional backing, along with the geographical concentration and inter connectivity of settlements were critical elements in determining success or failure in agriculture colonization.
C'est au début du siècle que les Mormons et les juifs etablirent dans l'Ouest canadien leurs colonies agricoles. La colonisation des Mormons, caractérisée par sa grande stabilite, réussit dans l'ensemble; rares furent les colonies qu'ils abandonnèrent. Par contre, presque toutes les colonies juives echouerent; abandonnant leurs terres, les colons se retirerent dans les centres urbains de l'Ouest. Une analyse comparative des deux groupes permet de conchre que leur stabilite agricole relative ne fut pas necessairement fonction de leur experience prealable en agriculture; elle ne fut pas non plus attribuable aux seules contraintes géographiques et clirnatiques.
Les structures sociales, les exigences religieuses, l'appui de leurs établissements en plus de la proximité d'autres colonies et leurs interrelations, tous ces facteurs s'avérèrent cruciaux pour déterminer la reussite ou l'échec de la colonisation agricole.  相似文献   
74.
ABSTRACT. Traditional models of regional diversification do not capture the trade-off between stability and living standards. In this paper, we characterize regions as open activity models subjected to both productivity and price shocks. We then partially rank small diversification policies by the direction in which they point away from the current industrial structure in mean-variance space. Some general patterns emerge. In particular, diversification for regional self-sufficiency and away from regional comparative advantage may be undesirable.  相似文献   
75.
76.
77.
78.
79.
This paper analyses the results of a survey of twenty-four recent cases of technology imports into India. Over the last thirty years, large firms in Indian industry have come under increasing competitive pressure from small firms which pay lower wages and which are also favoured by government policy. Most small firms obtain technology through informal channels within the country. But some import technology; and larger firms import it in their defence against competition from small firms. Larger firms, with a history and a reputation, have better access to technology from abroad; smaller firms often go through an extensive search before they find a willing technology supplier. Irrespective of size, firms that import technology within their own specialization are observed to put more effort into technology choice, absorption and adaptation. Indian policies of across-the-board import substitution, by promoting diversification into new products developed abroad, tend to discourage specialization and hence to encourage technology imports and to work against technology absorption and innovation.  相似文献   
80.
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