全文获取类型
收费全文 | 15605篇 |
免费 | 244篇 |
专业分类
各国政治 | 471篇 |
工人农民 | 1301篇 |
世界政治 | 677篇 |
外交国际关系 | 516篇 |
法律 | 9651篇 |
中国政治 | 48篇 |
政治理论 | 3148篇 |
综合类 | 37篇 |
出版年
2020年 | 104篇 |
2019年 | 128篇 |
2018年 | 1407篇 |
2017年 | 1345篇 |
2016年 | 1174篇 |
2015年 | 185篇 |
2014年 | 193篇 |
2013年 | 727篇 |
2012年 | 366篇 |
2011年 | 1096篇 |
2010年 | 1159篇 |
2009年 | 732篇 |
2008年 | 921篇 |
2007年 | 906篇 |
2006年 | 237篇 |
2005年 | 249篇 |
2004年 | 364篇 |
2003年 | 356篇 |
2002年 | 195篇 |
2001年 | 328篇 |
2000年 | 307篇 |
1999年 | 232篇 |
1998年 | 97篇 |
1997年 | 87篇 |
1996年 | 95篇 |
1995年 | 97篇 |
1994年 | 100篇 |
1993年 | 63篇 |
1992年 | 143篇 |
1991年 | 153篇 |
1990年 | 138篇 |
1989年 | 159篇 |
1988年 | 135篇 |
1987年 | 149篇 |
1986年 | 135篇 |
1985年 | 155篇 |
1984年 | 130篇 |
1983年 | 154篇 |
1982年 | 96篇 |
1981年 | 96篇 |
1980年 | 70篇 |
1979年 | 105篇 |
1978年 | 81篇 |
1977年 | 77篇 |
1976年 | 59篇 |
1975年 | 46篇 |
1974年 | 57篇 |
1973年 | 59篇 |
1971年 | 50篇 |
1970年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
821.
AbstractThis article explores the heterogeneous effects of the migration–remittance process on the educational attainment of Nepalese children. The results suggest that when controlling for remittances, the children of more educated or informed parents suffer from parental absence, while the children of less informed parents gain from migration, implying that the migration experience helps less educated parents estimate the value of and returns to education more precisely. The results also suggest that remittances help severely credit-constrained households enrol their children in school and prevent dropouts. These remittances help households that face less severe liquidity constraints increase their investment in quality education. 相似文献
822.
823.
824.
Catherine P. Bradshaw Tracy Evian Waasdorp Asha Goldweber Sarah Lindstrom Johnson 《Journal of youth and adolescence》2013,42(2):220-234
Recent media attention has increased interest in behavioral, mental health, and academic correlates of involvement in bullying. Yet, there has not been much interest in investigating the co-occurrence of other health-risk behaviors, such as gang membership, weapon carrying, and substance use. The potential influence of contextual factors, such as youth ethnicity, urbanicity, and school characteristics, also has been overlooked in previous research. The current study examined different subtypes of involvement in bullying—as primarily a victim, as primarily a bully, as both a victim and bully, and no involvement—and the association with significant health-risk behaviors, including engaging in violence and substance use, as well as academic problems. The analyses use self-report data from 16,302 adolescents (50.3 % female, 62.2 % Caucasian, 37.8 % African American) enrolled in 52 high schools. A series of three-level HLM analyses revealed that bullies and bully/victims were generally at greatest of risk of being involved in violence, engaging in multiple types of substance use, and having academic problems. These findings extend prior research by emphasizing a potential link between involvement in bullying and multiple health-risk behaviors, particularly among urban and African American high school youth. 相似文献
825.
Asha Goldweber Tracy Evian Waasdorp Catherine P. Bradshaw 《Journal of youth and adolescence》2013,42(2):206-219
Research on the role of race and urbanicity in bullying involvement has been limited. The present study examined bullying involvement subgroups that relate to race, urbanicity, and the perceived reason for the bullying. Self-report data were collected from 10,254 middle school youth (49.8 % female; 62.4 % Caucasian, 19.0 % African American, and 5.6 % Hispanic) and latent class analyses were used to identify three subtypes of bullying involvement: low involvement (50 %), victim (31.3 %), and bully-victim (18.7 %). Irrespective of urbanicity (urban vs. non-urban), African American youth were more likely to be members of either the victim or bully-victim classes than the low involvement class. Further exploration of the community context suggested that urbanicity was associated with the increased likelihood of having been racially bullied. Urban bully-victims were also more likely to have been bullied about money than non-urban bully-victims. Findings underscore the importance of addressing both race and urbanicity for culturally sensitive prevention programming. 相似文献
826.
The positive youth development perspective, a strength-based relational developmental systems model that focuses on mutually influential relationships between individuals and contexts, has been used to study thriving across the second decade of life. However, more attention has been paid empirically to identifying the features of the individual (e.g., intentional self regulation, hope, or purpose) or to enumerating the role of context-general ecological assets than to the nature of individual-context relationships linked to thriving within specific contexts. The goal of this special section is to provide initial research reports about context-specific instances of the thriving process. The research focuses on two contexts where many youth spend a considerable amount, and often the majority, of their time—school and out-of-school time sports activities. 相似文献
827.
Lindsay Rice Joan M. Barth Rosanna E. Guadagno Gabrielle P. A. Smith Debra M. McCallum 《Journal of youth and adolescence》2013,42(7):1028-1040
Social cognitive models examining academic and career outcomes emphasize constructs such as attitude, interest, and self-efficacy as key factors affecting students’ pursuit of STEM (science, technology, engineering and math) courses and careers. The current research examines another under-researched component of social cognitive models: social support, and the relationship between this component and attitude and self-efficacy in math and science. A large cross-sectional design was used gathering data from 1,552 participants in four adolescent school settings from 5th grade to early college (41 % female, 80 % white). Students completed measures of perceived social support from parents, teachers and friends as well as their perceived ability and attitudes toward math and science. Fifth grade and college students reported higher levels of support from teachers and friends when compared to students at other grade levels. In addition, students who perceived greater social support for math and science from parents, teachers, and friends reported better attitudes and had higher perceptions of their abilities in math and science. Lastly, structural equation modeling revealed that social support had both a direct effect on math and science perceived abilities and an indirect effect mediated through math and science attitudes. Findings suggest that students who perceive greater social support for math and science from parents, teachers, and friends have more positive attitudes toward math and science and a higher sense of their own competence in these subjects. 相似文献
828.
Joseph P. Ryan Abigail B. Williams Mark E. Courtney 《Journal of youth and adolescence》2013,42(3):454-465
Victims of child abuse and neglect are at an increased risk of involvement with the juvenile justice and adult correctional systems. Yet, little is known about the continuation and trajectories of offending beyond initial contact with law enforcement. Neglect likely plays a critical role in continued offending as parental monitoring, parental rejection and family relationships are instrumental in explaining juvenile conduct problems. This study sought to determine whether neglect is associated with recidivism for moderate and high risk juvenile offenders in Washington State. Statewide risk assessments and administrative records for child welfare, juvenile justice, and adult corrections were analyzed. The sample was diverse (24 % female, 13 % African American, 8 % Hispanic, 5 % Native American) and included all moderate and high risk juvenile offenders screened by juvenile probation between 2004 and 2007 (n = 19,833). Official records from child protection were used to identify juvenile offenders with a history of child neglect and to identify juvenile offenders with an ongoing case of neglect. Event history models were developed to estimate the risk of subsequent offending. Adolescents with an ongoing case neglect were significantly more likely to continue offending as compared with youth with no official history of neglect. These findings remain even after controlling for a wide range of family, peer, academic, mental health, and substance abuse covariates. Interrupting trajectories of offending is a primary focus of juvenile justice. The findings of the current study indicate that ongoing dependency issues play a critical role in explaining the outcomes achieved for adolescents in juvenile justice settings. The implications for improved collaboration between child welfare and juvenile justice are discussed. 相似文献
829.
Aerika S. Brittian Megan O’Donnell George P. Knight Gustavo Carlo Adriana J. Umaña-Taylor Mark W. Roosa 《Journal of youth and adolescence》2013,42(3):328-341
Experiences with perceived discrimination (e.g., perceptions of being treated unfairly due to race or ethnicity) are expected to impact negatively youths’ prosocial development. However, resilience often occurs in light of such experiences through cultural factors. The current longitudinal study examined the influence of perceived discrimination on the emergence of Mexican American adolescents’ later prosocial tendencies, and examined the mediating role of Mexican American values (e.g., familism, respect, and religiosity). Participants included 749 adolescents (49 % female) interviewed at 5th, 7th, and 10th grade. Results of the current study suggested that, although perceived discrimination was associated negatively with some types of prosocial tendencies (e.g., compliant, emotional, and dire) and related positively to public prosocial helping, the associations were mediated by youths’ Mexican American values. Directions for future research are presented and practical implications for promoting adolescents’ resilience are discussed. 相似文献
830.
This article investigates the life and works of Hortense Powdermaker (1896-1970). In contradistinction to the intellectual climate of her times, Powdermaker's intellectual trajectory can be characterised as eclectic, dynamic and forward thinking. Spanning nearly four decades, Powdermaker's academic career was dedicated to developing a distinct ‘anthropological vision’. Yet, although she conducted studies of culture and society that transcended structures of orthodoxy and charted alternative theoretical and methodological terrain, in turn establishing herself as a pioneer of contemporary anthropological thought, Powdermaker's work has failed to gain incorporation into wider disciplinary research agendas. Set within a sociology-of-intellectuals framework, it is argued that Powdermaker occupies a peripheral position in the history of anthropology – a position which does not adequately reflect the significance of her work – and that Powdermaker's greatest intellectual contribution was her innovative epistemology and sophisticated ‘anthropological vision’. Nonetheless, as a result of the powerful traditions and orthodox schools of thought which reigned supreme in mid-century anthropology and sociology, she was unable to exert any enduring influence on British or American social thought. 相似文献