全文获取类型
收费全文 | 10938篇 |
免费 | 42篇 |
专业分类
各国政治 | 337篇 |
工人农民 | 1135篇 |
世界政治 | 328篇 |
外交国际关系 | 357篇 |
法律 | 6629篇 |
中国政治 | 22篇 |
政治理论 | 2155篇 |
综合类 | 17篇 |
出版年
2020年 | 31篇 |
2019年 | 26篇 |
2018年 | 1305篇 |
2017年 | 1237篇 |
2016年 | 1057篇 |
2015年 | 81篇 |
2014年 | 53篇 |
2013年 | 217篇 |
2012年 | 247篇 |
2011年 | 980篇 |
2010年 | 1046篇 |
2009年 | 617篇 |
2008年 | 797篇 |
2007年 | 768篇 |
2006年 | 76篇 |
2005年 | 136篇 |
2004年 | 245篇 |
2003年 | 215篇 |
2002年 | 97篇 |
2001年 | 157篇 |
2000年 | 128篇 |
1999年 | 79篇 |
1998年 | 35篇 |
1997年 | 33篇 |
1996年 | 37篇 |
1995年 | 49篇 |
1994年 | 45篇 |
1993年 | 23篇 |
1992年 | 64篇 |
1991年 | 73篇 |
1990年 | 63篇 |
1989年 | 87篇 |
1988年 | 85篇 |
1987年 | 75篇 |
1986年 | 78篇 |
1985年 | 65篇 |
1984年 | 47篇 |
1983年 | 50篇 |
1982年 | 25篇 |
1981年 | 31篇 |
1979年 | 34篇 |
1978年 | 28篇 |
1977年 | 36篇 |
1975年 | 31篇 |
1974年 | 30篇 |
1973年 | 31篇 |
1972年 | 32篇 |
1971年 | 24篇 |
1969年 | 24篇 |
1968年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
911.
Engagement in school is crucial for academic success and school completion. Surprisingly little research has focused on the
relationship between student engagement and delinquency. This study examines whether engagement predicts subsequent school
and general misconduct among 4,890 inner-city Chicago elementary school students (mean age: 11 years and 4 months; 43.3% boys;
66.5% black; 28.8% Latino). To improve upon prior research in this area, we distinguish three types of engagement (emotional,
behavioral, and cognitive), examine whether the relationship between engagement and misconduct is bidirectional (misconduct
also impairs engagement), and control for possible common causes of low engagement and misconduct, including peer and family
relationships and relatively stable indicators of risk-proneness. Emotional and behavioral engagement predict decreases in
school and general delinquency. However, cognitive engagement is associated with increases in these outcomes. School and general
delinquency predict decreased engagement only in the cognitive domain. Suggestions for future research and implications for
policy are discussed. 相似文献
912.
913.
914.
915.
916.
917.
918.
919.
Carla I. Pedone 《Housing Policy Debate》2013,23(2):245-288
Abstract An issue now facing the federal government is whether and, if so, how to intervene to prevent mortgage prepayments and defaults on federally assisted low‐income rental units. This paper presents the preliminary estimates of the potential scope of the problem in terms of the possible incidence and timing of these actions, and the costs of preventing them. The estimates are based on modified versions of the model developed for the National Low Income Housing Preservation Commission's study, Preventing the Disappearance of Low Income Housing. An intermediate version of the modified model predicts 45 percent fewer defaults, 154,000 versus 280,000 units, and 45 percent lower total costs for preventing defaults, $4.6 billion versus $8.4 billion. On the other hand, 16 percent more prepayments are predicted, 283,000 versus 243,000 units. Estimated total costs for preventing prepayments are 17 percent lower, however — $8.5 billion versus $10.3 billion. 相似文献
920.