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   3922篇
  免费   112篇
管理学   575篇
民族学   34篇
人才学   1篇
人口学   368篇
丛书文集   34篇
理论方法论   382篇
综合类   21篇
社会学   2079篇
统计学   540篇
  2023年   24篇
  2021年   26篇
  2020年   67篇
  2019年   94篇
  2018年   100篇
  2017年   113篇
  2016年   104篇
  2015年   90篇
  2014年   93篇
  2013年   742篇
  2012年   110篇
  2011年   127篇
  2010年   100篇
  2009年   82篇
  2008年   123篇
  2007年   123篇
  2006年   89篇
  2005年   98篇
  2004年   97篇
  2003年   91篇
  2002年   124篇
  2001年   85篇
  2000年   84篇
  1999年   67篇
  1998年   60篇
  1997年   58篇
  1996年   46篇
  1995年   63篇
  1994年   54篇
  1993年   52篇
  1992年   47篇
  1991年   52篇
  1990年   43篇
  1989年   40篇
  1988年   59篇
  1987年   57篇
  1986年   26篇
  1985年   40篇
  1984年   46篇
  1983年   57篇
  1982年   32篇
  1981年   35篇
  1980年   29篇
  1979年   34篇
  1978年   40篇
  1977年   31篇
  1976年   35篇
  1975年   29篇
  1974年   18篇
  1972年   17篇
排序方式: 共有4034条查询结果,搜索用时 468 毫秒
191.
192.
Infants often protest the activities of their caregivers, and this particular social interaction may provide an important window on early communication and its development. This study used naturalistic methods to investigate the development of vocal protests. Fifteen mother‐infant dyads at each of 5 ages, from 3 to 18 months, were observed at home. Maternal behaviors of caregiving and prohibiting were tallied from videotapes, as were infants' protests of these behaviors. Maternal caregiving decreased with age, but maternal prohibitions increased. There were no changes over age in the probability of protesting maternal caregiving behavior; however, 12‐month‐olds were more likely to protest prohibitions than 6‐ or 8‐month‐olds. Older infants were also more likely to use intense protests, such as screams, than younger infants. These age‐related changes were mirrored by the differences in prohibitions and protests observed between 8‐month‐olds who could crawl and those who could not. Findings from this study were related to previous research on infant crying as an important part of the prelinguistic communication system.  相似文献   
193.
Three‐ to 4‐month‐old and 6‐ to 7‐month‐old infants were administered an infant version of the Face Dimensions Test that has been used with adults (e.g., Bukach, Le Grand, Kaiser, Bub, & Tanaka, 2008). Infants were familiarized with a photograph of a woman's face and then tested with the familiar face paired with a face differing in the (a) distance separating the eyes (a configural/eyes change), (b) distance between the nose and mouth (configural/mouth change), (c) size of the eyes (featural/eyes change), and (d) size of the mouth (featural/mouth change). Infants were shown to be more sensitive to (a) configural than featural change, and (b) change around the eyes versus the mouth. Implications for the development of face processing are discussed.  相似文献   
194.
195.
本文论述美国1997年后对华新政策。文章综述90年代起美国历届政府的对华的检讨,到1997年克林顿政府采取对华新政策,主要是稳定亚洲、中国大陆、台湾,以确保美国在亚洲战略地位和经济利益  相似文献   
196.
197.
Residential preferences and population distribution   总被引:2,自引:1,他引:1  
Public opinion research has revealed decided preferences for living in rural areas and small towns, and proponents of population deconcentration have interpreted this as support for their policies. This study, based on a national sample, yielded similar results, but when we introduced the additional possibility of a preference for proximity to a larger city, then the rural areas preferred were found, for most respondents, to be those within the commuting range of a metropolitan central city. Although persons wishing to live near large cities were found to be looking for the same qualities of living sought by those who prefer a more remote location, these findings are not, in general, consistent with the argument that public preferences support strategies of population dispersal into nonmetropolitan areas. Instead they indicate that most of those who wish to live in a different location favor the peripheral metropolitan ring areas that have, in fact, been growing rapidly by in-migration.  相似文献   
198.
A definition of inequalities in school inputs weighted according to their importance for educational and outputs is applied to the data from the 1966 Educational Opportunities Survey. The extent and source of inequalities due to race and region are examined. The results are discussed in terms of findings from more restricted definitions of inequalities, and practical policy considerations.  相似文献   
199.
Diversification gains in mean-variance efficiency derived from including real estate in financial asset portfolios are examined. Optimal financial and mixed-asset portfolios were generated by selecting from an investment universe including several distinct financial and real estate media. Deficiencies of previous studies were overcome by employing data with improved representativeness and comparability. The efficient mixed-asset portfolios dominated the efficient financial asset portfolios implying that purely financial asset diversification is inefficient. The optimal mixed-asset portfolio prescribed that approximately two-thirds of the investment wealth be allocated to real estate and one-third to the financial media.  相似文献   
200.
An integer linear programming model is presented for the scheduling of n products on m identical machines. The particular problem studied is one that occurs frequently in the fiberglass and textile industries. The model incorporates setup costs, lost production costs, and overtime costs. Due to the structure of the model, integer solutions can be obtained by explicitly restricting only a small number of the integer variables. This allows those responsible for scheduling to solve realistically sized problems in an efficient manner. Computational results are provided for a set of generated test problems.  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