首页 | 官方网站   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   90453篇
  免费   2968篇
  国内免费   17篇
社会科学   93438篇
  2023年   506篇
  2021年   575篇
  2020年   1519篇
  2019年   2209篇
  2018年   2082篇
  2017年   3175篇
  2016年   2379篇
  2015年   2059篇
  2014年   2650篇
  2013年   18916篇
  2012年   2449篇
  2011年   2255篇
  2010年   2061篇
  2009年   2243篇
  2008年   2150篇
  2007年   1970篇
  2006年   2194篇
  2005年   2356篇
  2004年   2174篇
  2003年   1889篇
  2002年   2000篇
  2001年   2000篇
  2000年   1769篇
  1999年   1679篇
  1998年   1492篇
  1997年   1331篇
  1996年   1292篇
  1995年   1319篇
  1994年   1291篇
  1993年   1270篇
  1992年   1258篇
  1991年   1195篇
  1990年   1175篇
  1989年   1024篇
  1988年   1124篇
  1987年   990篇
  1986年   892篇
  1985年   1063篇
  1984年   1122篇
  1983年   1002篇
  1982年   935篇
  1981年   864篇
  1980年   802篇
  1979年   862篇
  1978年   761篇
  1977年   635篇
  1976年   589篇
  1975年   573篇
  1974年   460篇
  1973年   388篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
991.
In studies of farming, the age of the principal decision-maker (PDM) has been associated with numerous farm structural and managerial features and has been widely accepted as a good indicator of the influence of life-cycle factors on decision-making. As such, it has become an important aspect of many quantitative studies of agricultural change. However, contemporary studies of family farming demonstrate that the concept of a single PDM in family farms is becoming an anachronism as alternative enterprises, pluriactivity and the scale of family farms force more diffuse management/operating systems. This raises questions concerning whether the age of the PDM can still be taken as representative of farm structure, strategy or life-cycle stage? Using a study conducted in the Grampian Mountains region of Scotland in 2003 this note investigates the impact of using an alternative index—compiled by averaging the age of family members working on the farm. It suggests that PDM age is a relatively poor indicator of farm structural and managerial features compared to a family age index and calls for researchers to think about alternative approaches to measuring ‘age’ as an indicator.  相似文献   
992.
993.
This article provides a discursive perspective on the dilemmas of sameness and difference feminisms and their consequences for change projects. It explores how equal opportunity officers dealing with gender issues and introducing equality legislation in practice construct the meaning of equal opportunities. The analysis of the interpretative repertoires and ideological dilemmas drawn upon in ten interviews shows the highly context‐specific use of four different repertoires constructing gender equality: the sameness, difference, bandwidth and deconstructive repertoire. Interpreting the shifts between repertoires from the perspective of the ideological dilemma, new avenues for change are explored. The article concludes that the simultaneous use of all possible theoretical perspectives might be a worthwhile objective.  相似文献   
994.
We examine how stand-up [sic] comedy constructs, circulates, perpetuates and/or disrupts stereotypical images of disabled persons in the United States. We use disabled people, rather than people-first language, to remind readers that disability is an ill-defined, culturally imposed attribute. Although humor is culturally specific, we draw on works of an international cadre of humanities scholars and social scientists to ground our analyses. We conclude that disability humor constitutes an emerging, liberatory art form. Disabled and non-disabled comedians elicit thought-provoking laughter and present disability as an interesting way to live. However, disabling humor still perpetuates stereotyping and isolation.  相似文献   
995.
Students in an academic training program were assessed for changes in their relationship and intervention skills following completion of the program. Positive improvements were found on some measures but not all. Additionally, trainee variables such as previous clinical experience. gender, age, marital stauts and scores on standardized admission tests were examined in relation to trainees' skills changes. Trainee characteristics were unrelated to changes in intervention skills. However, a number of relationships were found between trainee characteristics and changes in relationship skills.  相似文献   
996.
Summary This paper solves some D-optimal design problems for certain Generalized Linear Models where the mean depends on two parameters and two explanatory variables. In all of the cases considered the support point of the optimal designs are found to be independent of the unknown parameters. While in some cases the optimal design measures are given by two points with equal weights, in others the support is given by three point with weights depending on the unknown parameters, hence the designs are locally optimal in general. Empirical results on the efficiency of the locally optimal designs are also given. Some of the designs found can also be used for planning D-optimal experiments for the normal linear model, where the mean must be positive. This research was carried out in part at University College, London as an M.Sc. project. Thanks are due to Prof. I. Ford (University of Glasgow) and Prof. A. Giovagnoli (University of Perugia) for their valuable suggestions and critical observations.  相似文献   
997.
Child welfare workers and agencies are vulnerable to lawsuits. Recent court rulings have more clearly defined the liability of workers. The distinguishing variable is custody. Children injured while in the custody of the state are entitled to sue for damages. Children injured by their parent, even if under the supervision of a child welfare agency, are not entitled to claim a violation of their 14th Amendment rights. These cases are reviewed and strategies designed to minimize vulnerability are offered.  相似文献   
998.
A decade of research into the applications of artificial intelligence in statistics has finally resulted in the appearance of commercially available statistical expert systems. This paper takes a closer look at two of these systems, which are now commercially available on microcomputers, and shows what knowledge they actually contain and how they operate. It is concluded that although the technology and concepts that drive these systems could still benefit from further improvement, the real challenge lies in defining and constructing the statistical knowledge and strategy that should be incorporated and in presenting the results to the user's full advantage.  相似文献   
999.
In the design of experiments for estimating the slope of a response surface, slope-rotatability is a desirable property. In this paper, a measure is introduced that enables us to assess the degree of slope-rotatability for a given response surface design. The measure takes the value zero if and only if the design is slope-rotatable, and becomes larger as the design deviates from a slope-rotatable design. Examples of applying this measure to some response surface designs are also given.  相似文献   
1000.
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-23

京公网安备 11010802026262号