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   21554篇
  免费   291篇
管理学   3163篇
民族学   154篇
人才学   2篇
人口学   3355篇
丛书文集   63篇
理论方法论   1494篇
综合类   590篇
社会学   9486篇
统计学   3538篇
  2021年   75篇
  2020年   144篇
  2019年   200篇
  2018年   1871篇
  2017年   1980篇
  2016年   1332篇
  2015年   262篇
  2014年   278篇
  2013年   2047篇
  2012年   696篇
  2011年   1439篇
  2010年   1289篇
  2009年   999篇
  2008年   1102篇
  2007年   1259篇
  2006年   213篇
  2005年   503篇
  2004年   510篇
  2003年   496篇
  2002年   422篇
  2001年   301篇
  2000年   273篇
  1999年   248篇
  1998年   198篇
  1997年   169篇
  1996年   200篇
  1995年   165篇
  1994年   149篇
  1993年   154篇
  1992年   166篇
  1991年   166篇
  1990年   154篇
  1989年   139篇
  1988年   176篇
  1987年   167篇
  1986年   129篇
  1985年   160篇
  1984年   141篇
  1983年   161篇
  1982年   103篇
  1981年   107篇
  1980年   98篇
  1979年   108篇
  1978年   115篇
  1977年   83篇
  1976年   79篇
  1975年   87篇
  1974年   66篇
  1973年   57篇
  1972年   57篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
Many studies have provided evidence that, in birds, inexperienced breeders have a lower probability of breeding successfully. This is often explained by lack of skills and knowledge, and sometimes late laying dates in the first breeding attempt. There is growing evidence that in many species with deferred reproduction, some prebreeders attend breeding places, acquire territories and form pairs. Several behavioural tactics assumed to be associated with territory acquisition have been described in different species. These tactics may influence the probability of recruiting in the breeding segment of the population, age of first breeding, and reproductive success in the first breeding attempt. Here we addressed the influence of behaviour ('squatting') during the prebreeding period on demographic parameters (survival and recruitment probability) in a long-lived colonial seabird species: the kittiwake. We also investigated the influence of behaviour on reproductive trajectory. Squatters have a higher survival and recruitment probability, and a higher probability of breeding successfully in the first breeding attempt in all age-classes where this category is represented. The influence of behaviour is mainly expressed in the first reproduction. However, there is a relationship between breeding success in the first occasion and subsequent occasions. The influence of breeding success in the first breeding attempt on the rest of the trajectory may indirectly reflect the influence of behaviour on breeding success in the first occasion. The shape of the reproductive trajectory is influenced by behaviour and age of first breeding. There is substantial individual variation from the mean reproductive trajectory, which is accounted for by heterogeneity in performance among individuals in the first attempt, but there is no evidence of individual heterogeneity in the rate of change over time in performance in subsequent breeding occasions  相似文献   
53.
We propose some estimators of noncentrality parameters which improve upon usual unbiased estimators under quadratic loss. The distributions we consider are the noncentral chi-square and the noncentral F. However, we give more general results for the family of elliptically contoured distributions and propose a robust dominating estimator.  相似文献   
54.
Barnacle geese ( Branta leucopsis ) make annual migrations between breeding colonies in northern Europe and Eurasia to wintering grounds in Holland. During the migration, they sojourn for several weeks in five areas on the northern coast of Germany. Observers traverse these areas during the course of studying the flocks. Previous belief was that there was little exchange of birds among the five areas; however, some banded birds were observed in more than one area indicating that some movement takes place. In this presentation, we estimate the movement rates among the areas using open- and closed-population models.  相似文献   
55.
56.
This article examines trends in divorce attitudes of young adult women in the United States by educational attainment from 1974 to 2002. Women with 4‐year college degrees, who previously had the most permissive attitudes toward divorce, have become more restrictive in their attitudes toward divorce than high school graduates and women with some college education, whereas women with no high school diplomas have increasingly permissive attitudes toward divorce. We examine this educational crossover in divorce attitudes in the context of variables correlated with women's educational attainment, including family attitudes and religion, income and occupational prestige, and family structure. We conclude that the educational crossover in divorce attitudes is associated most strongly with work and family structure variables.  相似文献   
57.
Outsourcing of IT functions has become a widespread corporate practice, which has naturally led to concerns among IT works about how this affects their jobs. The issue is complex, and many companies are bringing their IT functions back inhouse. In light of this complexity, what skills do IT workers need to be com-petitive? We address this question first by reviewing the literature and then by examining two corporate case studies that have dealt with outsourcing issues. Based on this view of outsourcing, we discuss the skills that can provide a com-petitive advantage in the current environment.  相似文献   
58.
This article provides an overview of social trust, examining its various aspects and components. Trust is best understood in a sociological sense by focusing on its important relational characteristic. Following this lead, the article discusses briefly how social trust relates to social capital and examines factors that shape the development of social trust, along with outcomes related to variations in trust, classifying them by analytical level (i.e., individual, community, group, organizational, and societal). The article concludes by assessing the strengths and weaknesses of existing research and by identifying some important questions that have not yet been adequately addressed.  相似文献   
59.
We employ vector autoregressive techniques to determine the current state of the labor queue. Unemployment rate differentials have narrowed in recent years, potentially due to a change in the queue ordering, though a tight labor market and a stable queue would yield similar results. We find no evidence that the queue ordering has changed, which brings into question the resiliency of gains made by minority groups. We employ the same techniques to reveal the state of the queue across geographic regions and find that substantial differences exist across regions, implying variation in the relative labor force status of demographic groups.  相似文献   
60.
土木工程类复合型执业人才培养的研究与实践   总被引:1,自引:0,他引:1  
根据复合型执业人才培养模式的要求,对土木工程专业理论课程教学内容进行合并、增删、优化组合;在实践教学环节方面,安排大四学生在施工现场实践近1年,由项目经理、工程监理和发包方驻地工程师进行综合指导。理论与实践紧密结合的复合型执业人才培养的改革实践获得了极好的效果。  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