全文获取类型
收费全文 | 1002篇 |
免费 | 26篇 |
专业分类
各国政治 | 74篇 |
工人农民 | 34篇 |
世界政治 | 125篇 |
外交国际关系 | 64篇 |
法律 | 414篇 |
中国政治 | 9篇 |
政治理论 | 300篇 |
综合类 | 8篇 |
出版年
2023年 | 7篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2019年 | 28篇 |
2018年 | 30篇 |
2017年 | 30篇 |
2016年 | 30篇 |
2015年 | 20篇 |
2014年 | 21篇 |
2013年 | 185篇 |
2012年 | 22篇 |
2011年 | 27篇 |
2010年 | 24篇 |
2009年 | 28篇 |
2008年 | 37篇 |
2007年 | 20篇 |
2006年 | 29篇 |
2005年 | 29篇 |
2004年 | 32篇 |
2003年 | 34篇 |
2002年 | 28篇 |
2001年 | 33篇 |
2000年 | 34篇 |
1999年 | 26篇 |
1998年 | 21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 | 17篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1972年 | 3篇 |
1969年 | 4篇 |
排序方式: 共有1028条查询结果,搜索用时 15 毫秒
51.
Alexandre J. S. Morin A. Katrin Arens Christophe Maïano Joseph Ciarrochi Danielle Tracey Philip D. Parker Rhonda G. Craven 《Journal of youth and adolescence》2017,46(4):801-825
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
52.
Philip Woodhouse Gert Jan Veldwisch Jean-Philippe Venot Dan Brockington Hans Komakech Ângela Manjichi 《The Journal of peasant studies》2017,44(1):213-233
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
53.
Welton Chang Elissabeth Berdini David R. Mandel Philip E. Tetlock 《Intelligence & National Security》2018,33(3):337-356
Structured analytic techniques (SATs) are intended to improve intelligence analysis by checking the two canonical sources of error: systematic biases and random noise. Although both goals are achievable, no one knows how close the current generation of SATs comes to achieving either of them. We identify two root problems: (1) SATs treat bipolar biases as unipolar. As a result, we lack metrics for gauging possible over-shooting—and have no way of knowing when SATs that focus on suppressing one bias (e.g., over-confidence) are triggering the opposing bias (e.g., under-confidence); (2) SATs tacitly assume that problem decomposition (e.g., breaking reasoning into rows and columns of matrices corresponding to hypotheses and evidence) is a sound means of reducing noise in assessments. But no one has ever actually tested whether decomposition is adding or subtracting noise from the analytic process—and there are good reasons for suspecting that decomposition will, on balance, degrade the reliability of analytic judgment. The central shortcoming is that SATs have not been subject to sustained scientific of the sort that could reveal when they are helping or harming the cause of delivering accurate assessments of the world to the policy community. 相似文献
54.
Supreme Court confirmation hearings have been famously called a “vapid and hollow charade” by Elena Kagan. Indeed, perceptions of nominees’ refusal to answer questions about pending cases, prominent political issues, or give any hint of their ideological leanings have become a cornerstone of the modern confirmation process. We investigate the extent to which this reticence to speak of their ideological views, or candor, influences how individuals evaluate the nominee. To this end, we present the results of a survey experiment which examines how support for a hypothetical Supreme Court nominee is affected by information, especially when a nominee is presented to be very forthright or very reticent in answering ideological questions during the confirmation hearings. We find that while partisan compatibility with the president is the main determinant of support for a nominee, nominees who refuse to answer ideological questions can bolster support from respondents who would not support them on partisan grounds. We supplement these findings with observational state-level support data from real nominees over the last 40 years. 相似文献
55.
56.
57.
Although much criticized, the “Cosa Nostra” theory of organized crime continues to exert considerable influence over lawmakers and law enforcement officials. This theory has been extensively studied on a national level, but few local case studies trace the transition from the multiethnic organized crime of the 1930s and 1940s to the (supposed) Italian hegemony of the years since 1960. Philadelphia provides an excellent opportunity for such a study, as the base of a strong Jewish-dominated structure before 1960 and a “Mafia town” thereafter.A major concern of this article is the manner in which the history of crime in the city was retroactively rewritten during the 1970s, in order to provide a basis for contemporary theories and bureaucratic needs. 相似文献
58.
59.
60.
The adage that “it is always easier to fight the last war” is one that readily can be applied to the United States and its armed forces for not predicting the scale and type of operations encountered in the occupations of Iraq and Afghanistan. This article argues that the lack of preparation in the post-invasion phases arose from an institutional attachment to a preferred paradigm of warfare, as exemplified by the Persian Gulf War of 1991. This paradigm, though, has been substantially resurrected and re-configured to suit the fighting preferences of the American armed forces in its protracted encounters in Iraq and Afghanistan. Far from re-orienting its organization and mindset to meet the challenges of so-called counterinsurgency campaigns, as much current advocacy maintains, the military has reverted to the form of warfare it knows best. 相似文献