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   8781篇
  免费   335篇
  国内免费   87篇
管理学   1290篇
民族学   118篇
人口学   132篇
丛书文集   481篇
理论方法论   392篇
综合类   4494篇
社会学   683篇
统计学   1613篇
  2024年   54篇
  2023年   110篇
  2022年   157篇
  2021年   179篇
  2020年   220篇
  2019年   194篇
  2018年   226篇
  2017年   344篇
  2016年   272篇
  2015年   295篇
  2014年   255篇
  2013年   1173篇
  2012年   570篇
  2011年   477篇
  2010年   313篇
  2009年   275篇
  2008年   429篇
  2007年   521篇
  2006年   516篇
  2005年   461篇
  2004年   403篇
  2003年   342篇
  2002年   292篇
  2001年   249篇
  2000年   193篇
  1999年   112篇
  1998年   78篇
  1997年   57篇
  1996年   60篇
  1995年   60篇
  1994年   48篇
  1993年   30篇
  1992年   28篇
  1991年   32篇
  1990年   29篇
  1989年   22篇
  1988年   22篇
  1987年   12篇
  1986年   6篇
  1985年   13篇
  1984年   17篇
  1983年   14篇
  1982年   14篇
  1981年   15篇
  1980年   6篇
  1979年   4篇
  1978年   1篇
  1977年   3篇
排序方式: 共有9203条查询结果,搜索用时 15 毫秒
321.
In many diagnostic studies, multiple diagnostic tests are performed on each subject or multiple disease markers are available. Commonly, the information should be combined to improve the diagnostic accuracy. We consider the problem of comparing the discriminatory abilities between two groups of biomarkers. Specifically, this article focuses on confidence interval estimation of the difference between paired AUCs based on optimally combined markers under the assumption of multivariate normality. Simulation studies demonstrate that the proposed generalized variable approach provides confidence intervals with satisfying coverage probabilities at finite sample sizes. The proposed method can also easily provide P-values for hypothesis testing. Application to analysis of a subset of data from a study on coronary heart disease illustrates the utility of the method in practice.  相似文献   
322.
In this note we consider the equality of the ordinary least squares estimator (OLSE) and the best linear unbiased estimator (BLUE) of the estimable parametric function in the general Gauss–Markov model. Especially we consider the structures of the covariance matrix V for which the OLSE equals the BLUE. Our results are based on the properties of a particular reparametrized version of the original Gauss–Markov model.   相似文献   
323.
The variational approach to Bayesian inference enables simultaneous estimation of model parameters and model complexity. An interesting feature of this approach is that it also leads to an automatic choice of model complexity. Empirical results from the analysis of hidden Markov models with Gaussian observation densities illustrate this. If the variational algorithm is initialized with a large number of hidden states, redundant states are eliminated as the method converges to a solution, thereby leading to a selection of the number of hidden states. In addition, through the use of a variational approximation, the deviance information criterion for Bayesian model selection can be extended to the hidden Markov model framework. Calculation of the deviance information criterion provides a further tool for model selection, which can be used in conjunction with the variational approach.  相似文献   
324.
The purpose of this study was to examine the performance of the Thai-version of WHOQOL-BREF in assessing the quality of life (QoL) among Thai college students. The psychometric properties of WHOQOL-BREF were assessed in this study. The self-administered WHOQOL-BREF questionnaire was applied. A total of 407 Thai college students (male age = 20.5 ± 1.2; female age = 20.5 ± 1.2) participated in this study. Item-response distributions, internal consistency reliability, discriminant validity, criterion-related validity and construct validity through confirmatory analysis were analyzed. The findings indicate that the WHOQOL-BREF had acceptable internal consistency (α = 0.73–0.83 across four domains), all items highly correlated with corresponding domain scores (r = 0.53–0.80), the indices of a two-order confirmatory factor analysis (CFA) demonstrate that the data fit the model well with allowing covary of error variances of some items, all items had good property of criterion-related validity and item discrimination and, all three domain scores except the social relationship domain had significant associations with overall QoL or general health. The results suggest that the WHOQOL-BREF was reliable and valid to health professionals in the assessment of the QoL of college-based Thai youth, but some unsuitable items may be deleted in future studies.  相似文献   
325.
Fathers' roles in family life have changed dramatically over the past 50 years. In addition to ongoing breadwinning responsibilities, many fathers are now involved in direct caregiving and engagement with children. Yet there is considerable variation in what fathers do, especially depending on whether they live with or away from their child. In this article, the authors use data from the Fragile Families and Child Wellbeing Study (N = 3,869) to describe how fathers' economic capacities (money) and direct involvement with children (time) are associated over child ages 1 to 9 for resident versus nonresident fathers, net of confounding factors. They found suggestive evidence that money and time investments operate differently across residential contexts: Resident fathers experience a trade‐off between market work and time involved with children. In contrast, nonresident fathers' higher economic capacities are associated with more time involvement, underscoring the greater challenge for such fathers to remain actively involved.  相似文献   
326.
The study of family and religion has yet to elaborate on the social ties that connect these two important and changing institutions. Specifically, how does family formation (i.e., marriage and childrearing) impact social ties to religious communities? Using longitudinal data from the Portraits of American Life Study (2006–2012) and fixed effects regression models that control for time‐stable heterogeneity (N = 1,314), this study tests the effects of marriage and childrearing on changes in close congregational social ties. Fixed effects estimates suggest that marriage actually decreases close social ties to religious congregations, whereas rearing children within marital unions increases them. Thus, it is children, not marriage per se, that actually integrates married couples into religious communities. These contrasting effects tend to be the strongest among young adults, but they weaken with age as well as marital duration.  相似文献   
327.
Planning and evaluating projects often involves input from many stakeholders. Fusing and organizing many different ideas, opinions, and interpretations into a coherent and acceptable plan or project evaluation is challenging. This is especially true when seeking contributions from a large number of participants, especially when not all can participate in group discussions, or when some prefer to contribute their perspectives anonymously. One of the major breakthroughs in the area of evaluation and program planning has been the use of graphical tools to represent the brainstorming process. This provides a quantitative framework for organizing ideas and general concepts into simple-to-interpret graphs. We developed a new, open-source concept mapping software called R-CMap, which is implemented in R. This software provides a graphical user interface to guide users through the analytical process of concept mapping. The R-CMap software allows users to generate a variety of plots, including cluster maps, point rating and cluster rating maps, as well as pattern matching and go-zone plots. Additionally, R-CMap is capable of generating detailed reports that contain useful statistical summaries of the data. The plots and reports can be embedded in Microsoft Office tools such as Word and PowerPoint, where users may manually adjust various plot and table features to achieve the best visual results in their presentations and official reports. The graphical user interface of R-CMap allows users to define cluster names, change the number of clusters, select rating variables for relevant plots, and importantly, select subsets of respondents by demographic criteria. The latter is particularly useful to project managers in order to identify different patterns of preferences by subpopulations. R-CMap is user-friendly, and does not require any programming experience. However, proficient R users can add to its functionality by directly accessing built-in functions in R and sharing new features with the concept mapping community.  相似文献   
328.
吴晓刚  李忠路 《社会》2017,37(5):139-164
本文通过对“首都大学生成长追踪调查”中三所精英大学(北京大学、清华大学和中国人民大学)具有代表性样本的数据分析,从教育公平和人才选拔效率两个角度检验了自主招生政策实施的效果。研究结果表明,从教育公平的方面来讲,获得自主招生破格录取的学生更有可能来自父母受过高等教育的家庭、城市家庭和好的重点高中。从人才选拔效率的角度来讲,获得自主招生破格录取学生的学业表现、社会活动能力、非认知能力、毕业后的计划和实际去向与统招学生却并无显著差别。本文的发现对于如何完善自主招生政策、促进教育公平、科学选拔和培养优秀人才等议题具有重要的政策启示意义。  相似文献   
329.
Child to parent violence (CPV) involves continual and cumulative abusive actions perpetrated by children and adolescents towards their parents or caregivers. This abuse produces short‐term distress and ongoing long‐term harmful consequences for parents and their families. Practitioners, researchers and policy‐makers are increasingly challenged to identify, conceptualize and respond to this form of family violence. A major challenge is that parents and caregivers under‐report this abuse so there is a lack of awareness and understanding of their psychological experiences in relation to CPV. This research adopts an interpretative phenomenological approach to explore the psychological experience of CPV. Interviews were conducted with six New Zealand mothers and two grandmothers who all experienced CPV. This abuse was experienced as an ‘emotional bloody roller coaster’ of unconditional love through to hatred; as ‘judgement’ – self‐blame and others' blame of their parenting skills; and the ‘absent father’ in their adolescents' lives was drawn on as an explanation for the abuse. Taken together, these psychological experiences identify the silencing of CPV is related to parents' conflicting emotions towards their children, their thoughts and feelings about themselves and how other people view them, and the impact of an absent father figure in their children's everyday lives.  相似文献   
330.
The aim of this study is, by analysing children's and young people's discourses, to investigate their strategies in response to domestic violence episodes, in relation to their age. The empirical data come from individual interviews with children and young people (ages 8–20 years) who had experienced domestic violence and lived at refuges for abused women. The thematic analysis shows that the children describe a wide range of strategies before, during and after a violent episode, that all children act regardless of age and that strategies vary according not only to age but also to situation and context. The theoretical framework used is the sociology of childhood, and the analysis engages with theoretical concepts of age, agency and positioning.  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