全文获取类型
收费全文 | 1514篇 |
免费 | 107篇 |
国内免费 | 1篇 |
出版年
2023年 | 11篇 |
2022年 | 15篇 |
2021年 | 19篇 |
2020年 | 49篇 |
2019年 | 47篇 |
2018年 | 64篇 |
2017年 | 68篇 |
2016年 | 78篇 |
2015年 | 43篇 |
2014年 | 59篇 |
2013年 | 189篇 |
2012年 | 90篇 |
2011年 | 111篇 |
2010年 | 54篇 |
2009年 | 57篇 |
2008年 | 98篇 |
2007年 | 90篇 |
2006年 | 79篇 |
2005年 | 77篇 |
2004年 | 58篇 |
2003年 | 57篇 |
2002年 | 48篇 |
2001年 | 20篇 |
2000年 | 18篇 |
1999年 | 19篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 10篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1968年 | 2篇 |
1959年 | 2篇 |
1957年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有1622条查询结果,搜索用时 171 毫秒
961.
As can be seen from the recent Special Issue of MBR on propensity score analysis (PSA) methods, the use of PSA has gained increasing popularity for estimating causal effects in observational studies. However, PSA use with multilevel or clustered data has been limited, and to date there seems to have been no development of specialized graphics for such data. This paper introduces the multilevelPSA (http://multilevelPSA.r-forge.r-project.org) package for R that provides cluster-based functions for estimating propensity scores as well as graphics to exhibit results for multilevel data. This work extends to the multilevel case the framework for visualizing propensity score analysis introduced by Helmreich and Pruzek (2009). International data from the Programme for International Student Assessment (Organization for Economic Co-operation and Development, 2009) are comprehensively examined to compare private with public schools on reading, mathematics, and science outcomes after adjusting for covariate differences in the multilevel context. Particularly for analyses of large data sets, focusing on statistical significance is limiting. As can readily be seen, overall results favor “private” over “public” schools, at least for end of secondary school math achievement. But the graphics provide a more nuanced understanding of the nature and magnitude of adjusted differences for countries. Furthermore, the graphics are readily interpreted by a nontechnical audience. Broadly speaking, it is seen that modern graphics can enhance and extend conventional numerical summaries by focusing on details of what data have to say for multilevel comparisons of many countries based on propensity score methods. 相似文献
962.
Aggressive and Prosocial Behavior: Community Violence, Cognitive, and Behavioral Predictors Among Urban African American Youth 总被引:1,自引:0,他引:1
Susan D. McMahon Nathan R. Todd Andrew Martinez Crystal Coker Ching-Fan Sheu Jason Washburn Seema Shah 《American journal of community psychology》2013,51(3-4):407-421
We use longitudinal multilevel modeling to test how exposure to community violence and cognitive and behavioral factors contribute to the development of aggressive and prosocial behaviors. Specifically, we examine predictors of self-, peer-, and teacher-reported aggressive and prosocial behavior among 266 urban, African American early adolescents. We examine lagged, within-person, between-person, and protective effects across 2 years. In general, results suggest that higher levels of violence exposure and aggressive beliefs are associated with more aggressive and less prosocial peer-reported behavior, whereas greater self-efficacy to resolve conflict peacefully is associated with less aggression across reporters and more teacher-reported prosocial behavior. Greater knowledge and violence prevention skills are associated with fewer aggressive and more prosocial teacher-reported behaviors. Results also suggest that greater self-efficacy and lower impulsivity have protective effects for youth reporting higher levels of exposure to community violence, in terms of teacher-reported aggressive behavior and peer-reported prosocial behavior. Differences among reporters and models are discussed, as well as implications for intervention. 相似文献
963.
964.
Obesity and substance use are two common areas of research among adolescents. Interestingly, very little research examines the relationship between these two important health risk behaviors and the findings are inconsistent. Guided by Agnew’s general strain theory and using the Add Health data, we examine this neglected area of research. The current research has identified a link between weight strain and binge drinking and is supportive of the extant research on both general strain theory and the links between stigma, stress, and health. We also found some evidence that this relationship was gendered. Implications and future research directions are discussed. 相似文献
965.
966.
Relational framing theory asserts that dominance‐submission and affiliation‐disaffiliation tend to displace each other as frames for processing social interaction; involvement is argued to be a content‐free intensifier variable that contributes to judgments of dominance or affiliation as a function of the salient relational frame. The present study seeks to replicate and extend previous tests of these claims by evaluating three hypotheses: (a) The differential salience of dominance‐submission and affiliation‐disaffiliation frames as a function of the type of social episode is robust across same‐sex and cross‐sex friendship dyads; (b) the magnitude of the association between involvement and dominance and affiliation varies as a function of frame salience instantiated by the type of episode; and (c) attachment anxiety is positively correlated with the perceived relevance of both dominance‐submission and affiliation‐disaffiliation to social episodes. Results are consistent with all three of the hypotheses, but relational framing is unrelated to subscales operationalizing the comfort with closeness dimension of attachment orientation. 相似文献
967.
As a committee of the National Academy of Engineering recognized, ethics education should foster the ability of students to analyze complex decision situations and ill-structured problems. Building on the NAE’s insights, we report about an innovative teaching approach that has two main features: first, it places the emphasis on deliberation and on self-directed, problem-based learning in small groups of students; and second, it focuses on understanding ill-structured problems. The first innovation is motivated by an abundance of scholarly research that supports the value of deliberative learning practices. The second results from a critique of the traditional case-study approach in engineering ethics. A key problem with standard cases is that they are usually described in such a fashion that renders the ethical problem as being too obvious and simplistic. The practitioner, by contrast, may face problems that are ill-structured. In the collaborative learning environment described here, groups of students use interactive and web-based argument visualization software called “AGORA-net: Participate – Deliberate!”. The function of the software is to structure communication and problem solving in small groups. Students are confronted with the task of identifying possible stakeholder positions and reconstructing their legitimacy by constructing justifications for these positions in the form of graphically represented argument maps. The argument maps are then presented in class so that these stakeholder positions and their respective justifications become visible and can be brought into a reasoned dialogue. Argument mapping provides an opportunity for students to collaborate in teams and to develop critical thinking and argumentation skills. 相似文献
968.
Alexander Weigard Jason Chein Dustin Albert Ashley Smith Laurence Steinberg 《Developmental science》2014,17(1):71-78
Research suggests that the presence of peers influences adolescent risk‐taking by increasing the perceived reward value of risky decisions. While prior work has involved observation of participants by their friends, the current study examined whether observation by an anonymous peer could elicit similarly increased reward sensitivity. Late adolescent participants completed a delay discounting task either alone or under the belief that performance was being observed from a neighboring room by an unknown viewer of the same gender and age. Even in this limited social context, participants demonstrated a significantly increased preference for smaller, immediate rewards when they believed that they were being watched. This outcome challenges several intuitive accounts of the peer effect on adolescent risk‐taking, and indicates that the peer influence on reward sensitivity during late adolescence is not dependent on familiarity with the observer. The findings have both theoretical and practical implications for our understanding of social influences on adolescents' risky behavior. 相似文献
969.
970.