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   892篇
  免费   23篇
各国政治   70篇
工人农民   29篇
世界政治   81篇
外交国际关系   61篇
法律   371篇
中国政治   10篇
政治理论   288篇
综合类   5篇
  2023年   5篇
  2022年   3篇
  2021年   4篇
  2020年   6篇
  2019年   25篇
  2018年   21篇
  2017年   26篇
  2016年   28篇
  2015年   17篇
  2014年   21篇
  2013年   173篇
  2012年   22篇
  2011年   23篇
  2010年   23篇
  2009年   25篇
  2008年   33篇
  2007年   19篇
  2006年   28篇
  2005年   27篇
  2004年   32篇
  2003年   30篇
  2002年   22篇
  2001年   24篇
  2000年   18篇
  1999年   16篇
  1998年   18篇
  1997年   16篇
  1996年   13篇
  1995年   15篇
  1994年   13篇
  1993年   18篇
  1992年   11篇
  1991年   10篇
  1990年   10篇
  1989年   13篇
  1988年   12篇
  1987年   12篇
  1986年   9篇
  1985年   10篇
  1984年   10篇
  1983年   6篇
  1982年   7篇
  1981年   7篇
  1979年   4篇
  1978年   5篇
  1975年   3篇
  1974年   2篇
  1973年   2篇
  1972年   3篇
  1969年   4篇
排序方式: 共有915条查询结果,搜索用时 0 毫秒
41.
Friends provide important social contexts for student development. Research has shown that adolescent friends are similar to each other in their interest and values for different school subjects. Yet our current understanding does not extend to knowing whether selection, deselection, or socialization processes are responsible for this phenomena. Without this knowledge, it is very difficult for parents, teachers, and schools to know how and when to intervene. This study investigated selection, deselection, and socialization effects on adolescent students’ task values for academic (languages, math and science, and social sciences) and non-academic subject areas (the arts and physical education). A social network approach was used to examine two waves of annual data collected from school-based networks of adolescents in the first and second years of high school education in Finland (N?=?1419; female?=?48.6%; mean age at first measurement point?=?16). The results revealed that adolescents tended to select friends with similar levels of task values (friend selection) for the arts and physical education, but friends did not become more similar in these areas over time (friend socialization). In contrast, there was evidence of friend socialization, but not friend selection, for the academic school subjects. Across all subjects, differences in task values did not predict friendship dissolution (friend deselection). These findings suggest that to a significant extent, students make agentic choices in developing friendship with schoolmates based on their task values in non-academic subjects. The resultant friend contexts that individuals created, in turn, affected their task values in academic subject areas. These results shed light on the complexity of friend effect mechanisms on task values at the subject domain-specific level.  相似文献   
42.
Are internalizing and externalizing behavior problems interrelated via mutually reinforcing relationships (with each behavior leading to increases over time in levels of the other behavior) or mutually suppressing relationships (with each behavior leading to decreases over time in levels of the other behavior)? Past research on the directionality of these relationships has led to ambiguous results, particularly in adolescence. Furthermore, the extent to which prior results will generalize to adolescents with low levels of cognitive abilities remains unknown. This second limit is particularly important, given that these adolescents are known to present higher levels of externalizing and internalizing behaviors than their peers with average-to-high levels of cognitive abilities, and that the mechanisms involved in the reciprocal relationships between these two types of behaviors may differ across both populations. This study examines the directionality of the longitudinal relationships between externalizing and internalizing behavior problems as rated by teachers across three measurement waves (corresponding to Grades 8–10) in matched samples of 138 adolescents (34.78?% girls) with low levels of cognitive abilities and 556 adolescents (44.88?% girls) with average-to-high levels of cognitive abilities. The results showed that the measurement structure was fully equivalent across time periods and groups of adolescents, revealing high levels of developmental stability in both types of problems, and moderately high levels of cross-sectional associations. Levels of both internalizing and externalizing behaviors were higher among adolescents with low levels of cognitive abilities relative to those with average-to-high levels of cognitive abilities. Finally, the predictive analyses revealed negative reciprocal longitudinal relationships (i.e., mutually suppressing relationships) between externalizing and internalizing problems, a result that was replicated within samples of adolescents with low, and average-to-high levels of cognitive ability.  相似文献   
43.
The past decade has witnessed an intensifying focus on the development of irrigation in sub-Saharan Africa. It follows a 20-year hiatus in the wake of disappointing irrigation performance during the 1970s and 1980s. Persistent low productivity in African agriculture and vulnerability of African food supplies to increasing instability in international commodity markets are driving pan-African agricultural investment initiatives, such as the Comprehensive Africa Agricultural Development Programme (CAADP), that identify as a priority the improvement in reliability of water control for agriculture. The paper argues that, for such initiatives to be effective, there needs to be a re-appraisal of current dynamics of irrigation development in sub-Saharan Africa, particularly with respect to the role of small-scale producers’ initiatives in expanding irrigation. The paper reviews the principal forms such initiatives take and argues that official narratives and statistics on African irrigation often underestimate the extent of such activities. The paper identifies five key characteristics which, it argues, contradict widely held assumptions that inform irrigation policy in Africa. The paper concludes by offering a definition of ‘farmer-led irrigation’ that embraces a range of interaction between producers and commercial, government and non-government agencies, and identifies priority areas for research on the growth potential and impact of such interactions and strategies for their future development.  相似文献   
44.
This study examined the effects of neighborhood context on juvenile recidivism to determine if neighborhoods influence the likelihood of reoffending. Although a large body of literature exists regarding the impact of environmental factors on delinquency, very little is known about the effects of these factors on juvenile recidivism. The sample analyzed includes 7,061 delinquent male juveniles committed to community-based programs in Philadelphia, of which 74% are Black, 13% Hispanic, and 11% White. Since sample youths were nested in neighborhoods, a hierarchical generalized linear model was employed to predict recidivism across three general categories of recidivism offenses: drug, violent, and property. Results indicate that predictors vary across the types of offenses and that drug offending differs from property and violent offending. Neighborhood-level factors were found to influence drug offense recidivism, but were not significant predictors of violent offenses, property offenses, or an aggregated recidivism measure, despite contrary expectations. Implications stemming from the finding that neighborhood context influences only juvenile drug recidivism are discussed.  相似文献   
45.
Revisiting Adjusted ADA Scores for the U.S. Congress, 1947-2007   总被引:1,自引:0,他引:1  
Philip Habel Department of Political Science, Southern Illinois University Carbondale, Mailcode 4501, Carbondale, IL 62901 This paper replicates and extends Groseclose, Levitt, and Snyder,"Comparing Interest Group Scores Across Time and Chambers: AdjustedADA Scores for the U.S. Congress," which appeared in the AmericanPolitical Science Review (1999/93:33–50). We replicatethe most recent unpublished extension by Dr. Groseclose andresearch assistants for years 1947–1999, and then we extendthe analysis to include years 2000 through 2007. We make availableinflation-adjusted ADA scores from 1947 through 2007, allowingscholars to incorporate the most recent interest group scoresinto their analyses. Author's Note: Authors are listed alphabetically. The authorswish to thank Tim Groseclose for making available both the nominalADA scores from 1947 to 1999 and the Matlab program files usedin this analysis. SA gratefully acknowledges the support ofthe Hoover Institution during her time there as the 2006–07W. Glenn Campbell and Rita Ricardo-Campbell National Fellowand the Robert Eckles Swain National Fellow. PH wishes to thankboth the Dirksen Congressional Center and the National ScienceFoundation, doctoral dissertation improvement division grant493469, for their generous support. He also wishes to acknowledgethe valuable research assistance of James Lewis, Joshua Mitchell,and Matt Bergbower. Special thanks to J. Tobin Grant, ScottMcClurg, and Wendy Tam Cho for their helpful feedback and assistance.All errors are the responsibility of the authors. Replicationmaterials and programs are available on the Political AnalysisWeb site.  相似文献   
46.
Using a case study of a controversial mine in an indigenous area of Guatemala, this article explores the transnational dynamics of development and regulation of large‐scale extractive industry projects in the developing world. It examines the roles played in the Marlin mine dispute by national law, international law, international financial institutions, and corporate social responsibility. It concludes that these legal regimes have a role in protecting human rights but have not addressed the fundamental questions of democratic governance raised by this case.  相似文献   
47.
The assumption that candidates make a difference to electoral outcomes in British general elections is tested through a comparison of the 1983 and 1987 general elections. Incumbent's Constituency-specific Vote Change (ICVC) between the June 1983 and June 1987 British general elections is measured by subtracting the average regional vote change for the incumbent's party from the constituency vote change registered by the incumbent. Regression analysis finds ICVC to be most significantly influenced in both the Labour and Conservative parties by the incumbent's length of tenure, displayed especially in the higher ICVC registered by first-term incumbents than by more senior incumbents. Variables indicating the security or insecurity of the seat in electoral terms are significantly related to ICVC in the Conservative but not in the Labour case. The findings for Labour indicate ICVC to be greater where electoral security is greater. This finding might be explained by successful Conservative party concentration on constituencies in which Labour incumbents appear to be vulnerable.  相似文献   
48.
The defining properties of party identification long established for the United States fail with some frequency to be replicated in electoral systems abroad. A number of plausible suggestions have been made to account for this system-level variability: Most of these have some face merit, but none taken alone is adequate to provide a full cross-system explanation. Variation in party system size or fractionalization has recently been discussed as another source of differential dynamics of party loyalties. Unfortunately, the conventional means of assessing party identification properties are subject to rather severe artifacts, typically ignored, when comparisons are made across systems of very different party size. The conceptual stakes underlying key methods options for such comparisons—most notably, between continuous and discrete statistical tools—are examined. The use of continuous statistics for systems of very multiple parties rests on an assumption that voters do in some degree regard these party systems as imbedded in a continuous space. A simple test for this assumption is mounted in four systems and unsurprisingly it shows very clear support. Analysis of residuals beyond this obvious result add several points of less obvious information about the distribution of party affect in such systems.  相似文献   
49.
50.
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