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   26808篇
  免费   1441篇
各国政治   1157篇
工人农民   1144篇
世界政治   1833篇
外交国际关系   845篇
法律   17727篇
中国共产党   3篇
中国政治   167篇
政治理论   5198篇
综合类   175篇
  2021年   127篇
  2020年   505篇
  2019年   570篇
  2018年   731篇
  2017年   772篇
  2016年   846篇
  2015年   651篇
  2014年   704篇
  2013年   2726篇
  2012年   671篇
  2011年   744篇
  2010年   715篇
  2009年   755篇
  2008年   747篇
  2007年   741篇
  2006年   768篇
  2005年   672篇
  2004年   647篇
  2003年   583篇
  2002年   633篇
  2001年   1004篇
  2000年   898篇
  1999年   712篇
  1998年   396篇
  1997年   294篇
  1996年   321篇
  1995年   309篇
  1994年   304篇
  1993年   309篇
  1992年   497篇
  1991年   520篇
  1990年   493篇
  1989年   498篇
  1988年   509篇
  1987年   457篇
  1986年   545篇
  1985年   538篇
  1984年   444篇
  1983年   414篇
  1982年   306篇
  1981年   273篇
  1980年   241篇
  1979年   345篇
  1978年   197篇
  1977年   193篇
  1976年   164篇
  1975年   161篇
  1974年   203篇
  1973年   158篇
  1972年   153篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Considerable research has focused on the reliability and validity of informant reports of family behavior, especially maternal reports of adolescent problem behavior. None of these studies, however, has based their orientation on a theoretical model of interpersonal perception. In this study we used the social relations model (SRM) to examine family members’ reports of each others’ externalizing and internalizing problem behavior. Two parents and two adolescents in 69 families rated each others’ behavior within a round-robin design. SRM analysis showed that within-family perceptions of externalizing and internalizing behaviors are consistently due to three sources of variance; perceiver, target, and family effects. A family/contextual effect on informant reports of problem behavior has not been previously reported.  相似文献   
992.
993.
The present study provides a comparative analysis of sexual-minority and heterosexual emerging adult women’s experiences seeking support for sexual issues from parents and friends. Participants included 229 college women (88 sexual-minority women; 141 heterosexual women), ranging from 18 to 25 years of age, who provided written responses to an inquiry about a time they went to friends and parents for support for a issue related to their sexuality. Responses indicated that the majority of participants had sought support from either a parent or a friend and that mothers and female friends were more likely involved than fathers or male friends, respectively. Sexual issues that participants reported discussing with parents and friends were inductively grouped into five categories: dating and romantic relationships, sexual behavior, sexual health, identity negotiation, and discrimination and violence. Issues that were discussed differed based on sexual orientation identity and the source of support (parent or friend); they did not differ by age. Participants generally perceived parents and friends’ responses as helpful, though sexual-minority participants perceived both parents and friends’ responses as less helpful than did heterosexual participants. Overall, results suggest both similarities and differences between sexual-minority and heterosexual young women’s experiences seeking support for sexual issues from parents and friends.  相似文献   
994.
Research on coparenting documents that mothers’ and fathers’ coordination and mutual support in their parenting roles is linked to their offspring’s adjustment in childhood, but we know much less about the coparenting of adolescents. Taking a family systems perspective, this study assessed two dimensions of coparenting, parents’ shared decision-making and joint involvement in activities with their adolescents, and examined bidirectional associations between these coparenting dimensions and boys’ and girls’ risky behaviors and depressive symptoms across four time points (6 years) in adolescence. Participants were 201 mothers, fathers, and adolescents (M = 11.83, SD = .55 years of age at Time 1; 51 % female). Parents of sons shared more decisions, on average, than parents of daughters. On average, shared decision-making followed an inverted U shaped pattern of change, and parents’ joint involvement in their adolescents’ activities declined. Cross-lagged findings revealed that risky behavior predicted less shared decision-making, and shared decision-making protected against increased risky behavior for boys. For girls and boys, parents’ joint involvement predicted fewer risky behaviors, and lower levels of risky behavior predicted higher levels of joint involvement. In contrast, boys’ and girls’ depressive symptoms predicted less joint involvement. The discussion centers on the nature and correlates of coparenting during adolescence, including the role of child effects, and directions for future research on coparenting during this developmental period.  相似文献   
995.
Extensive evidence supports associations between early pubertal timing and adolescent externalizing behavior, but how and under which conditions they are linked is not fully understood. In addition, pubertal development is also characterized by variations in the relative speed at which individuals mature, but studies linking pubertal ‘tempo’ and outcomes are scarce. This study examined the mediating and moderating roles of spare time activities in associations between pubertal development and later delinquency, using data from a large (4,327 girls, 4,250 boys) longitudinal UK cohort (Avon Longitudinal Study of Parents and Children). Self-reports of Tanner stage were available from ages 9 to 14, spare time activities at age 12 and delinquency at age 15. Pubertal development was examined using latent growth models. Spare time activities were categorized using factor analyses, yielding four types (hanging out at home, hanging out outside, consumerist behavior, and sports/games), which were examined as mediators and moderators. Earlier and faster maturation predicted delinquency in boys and girls. Spare time activities partially mediated these links such that early maturing girls more often engaged in hanging out outside, which placed them at greater risk for delinquency. In addition, compared to their later and slower maturing counterparts, boys who matured earlier and faster were less likely to engage in sports/games, a spare time activity type that is linked to lower delinquency risk. No moderation effects were found. The findings extend previous research on outcomes of early maturation and show how spare time activities act as proxies between pubertal development and delinquency.  相似文献   
996.
Recent advancements in technology (e.g., social networking, texting) have created new ways for dating youth to relate to one another, including in abusive ways via “cyber dating abuse.” Cyber dating abuse is a form of teen dating violence that overlaps with other types of abuse (e.g., psychological) but also has several unique characteristics. Given the phenomenon’s limited presence in dating violence literature, we focus on identifying how experiencing cyber dating abuse relates to youths’ individual behaviors and experiences (e.g., substance use, sexual activity), psychosocial adjustment, school connection, family relationships, and partner relationships. A total of 3,745 youth (52 % female, 74 % White) in three northeastern states participated in the survey and reported currently being in a dating relationship or having been in one during the prior year. We found that experiences of cyber dating abuse were most significantly correlated with being female, committing a greater variety of delinquent behaviors, having had sexual activity in one’s lifetime, having higher levels of depressive symptoms, and having higher levels of anger/hostility. Further, cyber dating abuse appeared somewhat more strongly related to depressive symptoms and delinquency than did other forms of teen dating violence and abuse.  相似文献   
997.
Peer victimization is a well-known national and international problem, contributing to a range of emotional, social, and behavioral consequences. Using structural equation modeling, the authors tested a theoretical model suggesting that psychological distress and student engagement mediate the association between the experience of victimization and concurrent academic achievement. Participants were 469 (46.4 % male, 53.6 % female) 6th to 8th grade students, from randomly selected classrooms in 11 middle schools in a southeastern school district. Structural equation models of the hypothesized effects demonstrated adequate fit to the data, with both symptoms of psychological distress and engagement mediating the relationship between victimization and academic achievement. In general, the results suggest that victimization predicts diminished academic achievement by way of psychological distress and poorer engagement in classroom and academic tasks. However, the direct relationship between victimization and measures of achievement lacked significance across many correlational and path analyses conducted. These findings have implications for researchers and practitioners in understanding how psychological distress and student engagement are associated with the academic performance of students who experience peer victimization.  相似文献   
998.
Alcohol is the most commonly used substance among adolescents in the United States, and adolescent drinking is associated with various health risk behaviors. Given the prevalence and consequences of adolescent drinking, understanding family factors that contribute to adolescent drinking is an important area for research. This study used three waves of data to evaluate a family stress model in which economic hardship is indirectly related to adolescent problem drinking through maternal psychological distress, parenting behaviors, and adolescent externalizing behaviors. Respondents included 300 mothers (71 % Black, 29 % White) and adolescents (51 % male) who were interviewed when adolescents were ages 10, 14, and 16. Structural equation modeling was used to test the hypothesized model and findings supported our hypothesized model. Economic hardship was positively related to maternal psychological distress. Maternal psychological distress was negatively associated with supportive parenting, which in turn was negatively associated with externalizing problems. Externalizing problems were positively associated with problem drinking. In support of our hypothesis regarding indirect effects, economic hardship was indirectly related to problem drinking through maternal psychological distress, parenting behaviors, and adolescent externalizing problems. The findings from this study highlight the role of family processes in adolescent problem drinking.  相似文献   
999.
Most adolescents with depressive disorders do not receive any mental health services, even though effective treatments exist. Although research has examined numerous individual-level factors associated with mental health service use among depressed adolescents, less is known about the role of contextual factors. This study examines the relationship between contextual-level socioeconomic status (SES) and clinic-based mental health counseling use among US adolescents with high depressive symptoms in urban and suburban areas. Data from the first two waves of the National Longitudinal Study of Adolescent Health (N = 1,133; 59 % female) were analyzed using multilevel logistic models in which adolescents were nested within counties. After controlling for individual-level predisposing, enabling, and need characteristics, as well as county racial/ethnic composition, county SES was positively associated with clinic-based counseling use among depressed youth. A one standard deviation increase in the county affluence index was associated with 43 % greater odds of receiving any clinical counseling services. Furthermore, the positive relationship between county affluence and clinical counseling use was no longer significant after controlling for the county supply of mental health specialist physicians. The results indicate that county residential context is a key correlate of mental health service use among depressed adolescents, such that those who live in lower SES counties with fewer mental health specialists are less likely to receive treatment.  相似文献   
1000.
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