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   26860篇
  免费   1447篇
各国政治   1129篇
工人农民   1144篇
世界政治   1853篇
外交国际关系   877篇
法律   17722篇
中国共产党   2篇
中国政治   169篇
政治理论   5235篇
综合类   176篇
  2021年   133篇
  2020年   506篇
  2019年   572篇
  2018年   749篇
  2017年   776篇
  2016年   853篇
  2015年   649篇
  2014年   711篇
  2013年   2730篇
  2012年   672篇
  2011年   751篇
  2010年   714篇
  2009年   769篇
  2008年   753篇
  2007年   766篇
  2006年   784篇
  2005年   658篇
  2004年   646篇
  2003年   578篇
  2002年   620篇
  2001年   1008篇
  2000年   901篇
  1999年   716篇
  1998年   391篇
  1997年   293篇
  1996年   318篇
  1995年   314篇
  1994年   297篇
  1993年   304篇
  1992年   505篇
  1991年   521篇
  1990年   490篇
  1989年   489篇
  1988年   493篇
  1987年   456篇
  1986年   543篇
  1985年   539篇
  1984年   440篇
  1983年   415篇
  1982年   303篇
  1981年   270篇
  1980年   245篇
  1979年   342篇
  1978年   196篇
  1977年   194篇
  1976年   163篇
  1975年   161篇
  1974年   203篇
  1973年   157篇
  1972年   153篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Sipping alcohol during childhood may be a marker of differentiation as regards children’s future risk of underage drinking; yet very little is known about alcohol use when it occurs among elementary school-aged children. The purpose of the present study is to examine alcohol sipping behavior in a sample of third-grade school children to learn whether sipping is associated with attributes that could increase children’s likelihood of further underage drinking. We collected telephone interview data from 1,050 mothers and their third grade children (mean age 9.2 years; 48.2 % male) residing in the Southeastern United States. The majority of mothers were White non-Hispanic (69.02 %) or Black non-Hispanic (21.3 %); most (85 %) lived in households shared with fathers or other adult caretakers. We hypothesized that children who sip alcohol would score lower than abstinent peers on indicators of competence and score higher on indicators of exposure to alcohol-specific socialization by parents and peers. A multivariate model controlling for frequency of parent alcohol use and demographic covariates showed that children who had sipped alcohol were significantly less likely than abstinent peers to affirm indicators of competence and significantly more likely to affirm indicators of exposure to alcohol specific socialization by parents and by same age peers. These preliminary findings suggest that developmental attributes associated with risk of underage drinking begin to differentiate at least as young as middle childhood. Research is needed to test prospectively for continuity between alcohol risk attributes present in middle childhood and future alcohol use.  相似文献   
982.
Preliminary research suggests that partner violence is a problem among lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQ) college youth. However, there is no study to date with college youth on the factors associated with perpetration of same-sex partner violence, which is needed to inform prevention efforts specific to this population. Thus, the purpose of the current study was to assess how facets of minority stress (i.e., sexual-orientation-related victimization, sexual minority stigma, internalized homonegativity, sexual identity concealment) relate to physical, sexual, and psychological partner violence perpetration among LGBTQ college youth (N = 391; 49 % identified as men; 72 % Caucasian; M age: 20.77 years). At the bivariate level, physical perpetration was related to identity concealment and internalized homonegativity; sexual perpetration was related to internalized homonegativity; and psychological perpetration was related to sexual-orientation-related victimization. However, at the multivariate level (after controlling for concurrent victimization), psychological perpetration was unrelated to minority stress variables, whereas physical and sexual perpetration were both related to internalized homonegativity; physical perpetration was also related to identity concealment. These results underscore the utility of understanding partner violence among LGBTQ youth through a minority stress framework. Moreover, the current study highlights the need for a better understanding of factors that mediate and moderate the relationship between minority stress and partner violence perpetration among LGBTQ youth in order to inform prevention and intervention efforts.  相似文献   
983.
Prior empirical work has documented that the dynamics of social standing can play a critical role in the perpetration and receipt of aggression during adolescence. Recently, investigators have emphasized the emergence of new, electronic modalities for aggressive acts. Our longitudinal project therefore considered electronic forms of aggression and victimization as correlates of social standing. We recruited 415 ninth grade students (53 % female) from a high school in Southern California. In the spring of two consecutive school years, participants completed peer nominations assessing their social standing, aggression, and victimization. More popular youths were concurrently more electronically aggressive and victimized than their peers. Popularity also was associated with increases in electronic aggression over time. In turn, electronic aggression was related to increases in popularity for girls and decreases for boys. We additionally found concurrent, positive associations between social acceptance and electronic forms of aggression and victimization, although these effects held only at the first time point. Among adolescent males, social acceptance also was related to increases in electronic victimization over time. Overall, our results suggest that adolescents may rely on electronic aggression to establish and maintain a privileged position in their peer hierarchy. Our results additionally highlight that popular and accepted youths, who likely possess a large, digitally-connected social network, may be at increased risk for electronic victimization.  相似文献   
984.
Family is an important socialization context for youth as they move through early adolescence. A significant feature of this complex socialization context is the accumulation of potential family risk factors that may compromise youth adjustment. This study examined cumulative family risk and adolescents’ adjustment difficulties in 416 two-parent families using four waves of annual longitudinal data (51 % female youth). Risk factors in four family domains were examined: socioeconomic, parents’ psychological realm, marital, and parenting. Cumulative family risk experienced while in 6th grade was associated concurrently with daughters’ higher internalizing problems and with increased internalizing problems during early adolescence. Cumulative family risk was associated concurrently with sons’ higher externalizing problems and with daughters’ increased externalizing problems over time. Cumulative family risk was associated concurrently with lower grades and with declining grades over time for both daughters and sons. The number of risk domains also was associated with youths’ adjustment difficulties during early adolescence, providing evidence that risk in two-parent families involves more than ineffective parenting. These findings suggest a critical need to provide strong support for families in reducing a variety of stressors across multiple family domains as their children traverse early adolescence.  相似文献   
985.
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   
986.
Age is one of the most robust correlates of criminal behavior. Yet, explanations for this relationship are varied and conflicting. Developmental theories point to a multitude of sociological, psychological, and biological changes that occur during adolescence and adulthood. One prominent criminological perspective outlined by Gottfredson and Hirschi claims that age has a direct effect on crime, inexplicable from sociological and psychological variables. Despite the attention this claim has received, few direct empirical tests of it have been conducted. We use data from Pathways to Desistance, a longitudinal study of over 1,300 serious youthful offenders (85.8 % male, 40.1 % African-American, 34.3 % Hispanic, 21.0 % White), to test this claim. On average, youths were 16.5 years old at the initial interview and were followed for 7 years. We use multilevel longitudinal models to assess the extent to which the direct effects of age are reduced to statistical and substantive non-significance when constructs from a wide range of developmental and criminological theories are controlled. Unlike previous studies, we are able to control for changes across numerous realms emphasized within differing theoretical perspectives including social control (e.g., employment and marriage), procedural justice (e.g., perceptions of the legitimacy and fairness of the legal system), learning (e.g., gang membership and exposure to antisocial peers), strain (e.g., victimization and relationship breakup), psychosocial maturity (e.g., impulse control, self-regulation and moral disengagement), and rational choice (e.g., costs and rewards of crime). Assessed separately, these perspectives explain anywhere from 3 % (procedural justice) to 49 % (social learning) of the age-crime relationship. Together, changes in these constructs explain 69 % of the drop in crime from ages 15 to 25. We conclude that the relationship between age and crime in adolescence and early adulthood is largely explainable, though not entirely, attributable to multiple co-occurring developmental changes.  相似文献   
987.
The peer context is a central focus in research on adolescent risk behaviors but few studies have investigated the role of the peer context in the perpetration of adolescent dating violence. This longitudinal study examined between-subjects and within-person contemporaneous and lagged effects of peer attributes, measured with social network analyses, on trajectories of dating violence perpetration and determined if effects varied by grade and/or sex of the adolescent. Data are from adolescents who participated in a five-wave panel study beginning when they were in 7 through 9th grade and ending when they were in 10 through 12th grade (n = 3,412); half were male, 40.5 % were white, 49.9 % were black and 10.4 % were of another race/ethnicity. Significant between-subjects effects indicate that adolescents who typically have friends who use dating violence, and girls who are typically high in social status, are at increased risk for using dating violence throughout adolescence. Adolescents who typically have high quality friendships and girls who typically have friends with pro-social beliefs are at decreased risk for using dating violence throughout adolescence. Significant within-person contemporaneous effects indicate that both boys and girls reported lower levels of dating violence than usual at times when they had more friends with pro-social beliefs, and reported higher levels of dating violence than usual at times when they had higher social status. None of the lagged effects were significant and none of the effects varied across grade. These findings suggest that the peer context plays an important role in the development of the perpetration of adolescent dating violence.  相似文献   
988.
ABSTRACT

This article is situated within nascent debates on the role of academics within food sovereignty movements. Drawing on insights from a collective autoethnography, we report on our experiences conducting three food sovereignty research projects in different contexts and at different scales. We suggest that that the principles and practices of food sovereignty translate into a food sovereignty research praxis. This consists of three pillars focusing on people (humanizing research relationships), power (equalizing power relations) and change (pursuing transformative orientations). This article discusses these pillars and analyzes the extent to which we were able to embody them within our projects.  相似文献   
989.
990.
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