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   25832篇
  免费   574篇
各国政治   984篇
工人农民   1621篇
世界政治   1714篇
外交国际关系   972篇
法律   15082篇
中国共产党   3篇
中国政治   91篇
政治理论   5746篇
综合类   193篇
  2021年   95篇
  2020年   248篇
  2019年   305篇
  2018年   1570篇
  2017年   1557篇
  2016年   1420篇
  2015年   389篇
  2014年   401篇
  2013年   1858篇
  2012年   621篇
  2011年   1322篇
  2010年   1311篇
  2009年   957篇
  2008年   1172篇
  2007年   1138篇
  2006年   481篇
  2005年   479篇
  2004年   594篇
  2003年   581篇
  2002年   437篇
  2001年   707篇
  2000年   641篇
  1999年   519篇
  1998年   307篇
  1997年   264篇
  1996年   228篇
  1995年   247篇
  1994年   269篇
  1993年   229篇
  1992年   346篇
  1991年   375篇
  1990年   335篇
  1989年   353篇
  1988年   320篇
  1987年   339篇
  1986年   348篇
  1985年   336篇
  1984年   297篇
  1983年   325篇
  1982年   262篇
  1981年   238篇
  1980年   182篇
  1979年   253篇
  1978年   173篇
  1977年   154篇
  1976年   132篇
  1975年   120篇
  1974年   136篇
  1973年   120篇
  1972年   112篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
This study examined the effects of neighborhood context on juvenile recidivism to determine if neighborhoods influence the likelihood of reoffending. Although a large body of literature exists regarding the impact of environmental factors on delinquency, very little is known about the effects of these factors on juvenile recidivism. The sample analyzed includes 7,061 delinquent male juveniles committed to community-based programs in Philadelphia, of which 74% are Black, 13% Hispanic, and 11% White. Since sample youths were nested in neighborhoods, a hierarchical generalized linear model was employed to predict recidivism across three general categories of recidivism offenses: drug, violent, and property. Results indicate that predictors vary across the types of offenses and that drug offending differs from property and violent offending. Neighborhood-level factors were found to influence drug offense recidivism, but were not significant predictors of violent offenses, property offenses, or an aggregated recidivism measure, despite contrary expectations. Implications stemming from the finding that neighborhood context influences only juvenile drug recidivism are discussed.  相似文献   
992.
This study used data from a sample of 6th to 12th grade students (N = 48,641, 51% female), nested in 192 schools, to determine if the influence of family-based protective factors varied across different school contexts. Hierarchical logistic regression models were used to examine the effects of individual-level family protective factors, relative to school-level aggregates of the same factors, on recent (past 30 days) use of cigarettes, alcohol, and marijuana. Cross-level interactions indicated that the effect of the student’s level of family protection, relative to other students in their school, differed depending on the aggregated school level of family protection. The results suggested that the benefit of belonging to a well-functioning family was more influential for students attending schools characterized by higher-than-average aggregated levels of protection compared to students attending schools of lower-than-average protection. Thus, family-level factors offered less protection for students in relatively high-risk school contexts. These results were consistent with a protective–reactive interaction and suggest that a thorough understanding of adolescent substance use must consider the complex interplay among adolescents, their families, and their social environments.  相似文献   
993.
Underage drinking is among the most serious of public health problems facing adolescents in the United States. Recent concerns have centered on young women, reflected in media reports and arrest statistics on their increasing problematic alcohol use. This study rigorously examined whether girls’ alcohol use rose by applying time series methods to both arrest data, Uniform Crime Reports, and self-report data from Monitoring the Future, a nationally representative long-term survey gathered independently of crime control agents. All self-reported drinking behaviors across all age groups show declining or unchanged female rates and no significant change in the gender gap, while the official source displays a steady narrowing gender gap and some increase of female arrest rates for liquor law violations. Results indicate that social control measures applied to underage drinking have shifted to target young women’s drinking patterns, but their drinking has not become more widespread/problematic. Girls’ increased alcohol use and abuse is a socially constructed problem, rather than the result of normalization of drinking or more strain in girls’ lives. Future underage drinking policies and practices that apply legal intervention strategies to less chronic adolescent drinking behaviors will increase the visibility of girls’ drinking.  相似文献   
994.
Latinas in the United States are at a disproportionate risk for STDs and sexual risk behaviors. Among Latinas, acculturation has been found to be one of the most important predictors of these behaviors. Therefore, this study examined the longitudinal association between Latina adolescents’ level of acculturation and multiple sexual risk outcomes, including self-report STD diagnosis, four or more life-time sex partners, regret of sexual initiation after alcohol use, and lack of condom use during young adulthood. Based on the National Longitudinal Study of Adolescent Health (Add Health), this study includes a nationally representative sample of 1,073 Latina adolescents (ages 11–20 at Wave 1) transitioning into young adulthood (ages 18–27 at Wave 3). Our findings indicate that more acculturated Latinas who spoke English at home were more likely to have STDs and to exhibit sexual risk behaviors than Latinas who were foreign-born and did not use English at home. Interventions that aim to promote sexual and reproductive health among young Latinas should take into consideration their different levels of acculturation. This approach holds greater potential for reducing health disparities among Latinas.  相似文献   
995.
Previous findings have shown both beneficial and adverse effects of parents’ attempts to influence adolescents’ eating habits. The current study examined the differential effect of parents’ persuasion (e.g., encouragement, giving information) and pressure tactics (e.g., guilt induction, ridicule) and the moderating influence of parental warmth on older adolescents’ emotional and behavioral responses. An ethnically diverse sample of 336 older adolescents (M age = 18.6; SD = 1.1; 58.0% female) were surveyed. Adolescents who reported higher levels of pressure tactics by parents reported more negative affect and behavioral resistance. Perceived parental warmth moderated the influence of persuasion tactics, but not pressure tactics. For adolescents with low parental warmth, high levels of persuasion were associated with more negative emotional and behavioral responses; persuasion had the opposite associations for adolescents with high parental warmth. These results suggest that parental warmth plays an important role in how older adolescents respond to parents’ persuasion tactics. However, when parents use more forceful pressure tactics to influence eating habits, adolescents react negatively regardless of the overall quality of the parent–adolescent relationship.  相似文献   
996.
The purpose of the present study was to examine relations between adolescents’ social cognitions regarding parenting practices and adolescents’ prosocial behavioral tendencies. A mediation model was tested whereby the degree to which adolescents perceived their parents as responding appropriately to their prosocial and antisocial behaviors was hypothesized to predict adolescents’ tendencies toward prosocial behavior indirectly by way of adolescents’ prosocial values. Adolescents (N = 140; M age = 16.76 years, SD = .80; 64% girls; 91% European Americans) completed measures of prosocial values and of the appropriateness with which they expected their parents to react to their prosocial and antisocial behaviors. In addition, teachers and parents rated the adolescents’ tendencies for prosocial behaviors. A structural equation model test showed that the degree to which adolescents expected their parents to respond appropriately to their prosocial behaviors was related positively to their prosocial values, which in turn was positively associated with their tendencies to engage in prosocial behaviors (as reported by parents and teachers). The findings provide evidence for the central role of adolescents’ evaluations and expectancies of parental behaviors and of the role of values in predicting prosocial tendencies. Discussion focuses on the implications for moral socialization theories and on the practical implications of these findings in understanding adolescents’ prosocial development.  相似文献   
997.
Studies using valid measures of monitoring activities have not found the anticipated main effects linking greater monitoring activity with fewer behavioral problems. This study focused on two contexts in which monitoring activities may be particularly influential. Early adolescents (n = 218, M age = 11.5 years, 51% female, 49% European American, 47% African American) reported their unsupervised time, beliefs about the legitimacy of their parents’ authority, and their own involvement in antisocial behavior. Mothers and adolescents reported their perceptions of adolescent disclosure and parental solicitation and control. Adolescents’ perceptions of greater parental solicitation at age 11 were associated with less antisocial behavior at age 12 (when controlling for age 11 antisocial behavior) among adolescents reporting large amounts of unsupervised time and weak legitimacy beliefs. Perceived parental solicitation may be an effective deterrent of antisocial behavior when adolescents spend a lot of time unsupervised and for adolescents who are likely to challenge the legitimacy of their parents’ authority.  相似文献   
998.
While having a purpose in life has been theorized as a developmental asset, the extent to which adolescents cultivate a meaningful sense of direction is not well understood. In the present study, cluster analysis was used to classify adolescents by levels of purpose exploration and commitment. The sample (N = 318; 55% female) consisted of youth aged 14–18 and was predominantly White/non-Hispanic (76.3%). Results supported four meaningful yet distinguishable profiles of youth purpose that are largely consistent with theories on identity formation: Achieved, Foreclosed, Uncommitted, and Diffused. Hypothesized linkages with affect and hope were established across the profiles such that positive emotions and goal-directed thinking were most apparent among Achieved and Foreclosed youth and least apparent among Diffused and Uncommitted youth. Overall, findings demonstrate the inherent complexity in adolescents’ engagement with purpose and suggest a correspondence between stronger commitments to purpose and youths’ sense of personal agency and well-being.  相似文献   
999.
The main aim of this study was to investigate the causal nature of the relationship between adolescents’ risky sexual behavior on the internet and their perceptions of this behavior. Engagement in the following online behaviors was assessed: searching online for someone to talk about sex, searching online for someone to have sex, sending intimate photos or videos to someone online, and sending one’s telephone number and address to someone exclusively known online. The relationship between these behaviors and adolescents’ perceptions of peer involvement, personal invulnerability, and risks and benefits was investigated. A two-wave longitudinal study among a representative sample of 1,445 Dutch adolescents aged 12–17 was conducted (49% females). Autoregressive cross-lagged structural equation models revealed that perceived peer involvement, perceived vulnerability, and perceived risks were all significant predictors of risky sexual online behavior 6 months later. No reverse causal paths were found. When the relationships between perceptions and risky sexual online behavior were modeled simultaneously, only perceived peer involvement was a determinant of risky sexual online behavior. Findings highlight the importance of addressing peer involvement in future interventions to reduce adolescents’ risky sexual online behavior.  相似文献   
1000.
Self-harm is widely recognized as a significant adolescent social problem, and recent research has begun to explore its etiology. Drawing from Agnew’s (1992) social psychological strain theory of deviance, this study considers this issue by testing three hypotheses about the effects of traditional and cyber bullying victimization on deliberate self-harm and suicidal ideation. The data come from a school-based survey of adolescents in a rural county of a southeastern state (n = 426); 50% of subjects are female, their mean age was 15 years, and non-Hispanic whites represent 66% of the sample. The analysis revealed that both types of bullying are positively related to self-harm and suicidal ideation, net of controls. Moreover, those relationships are partially mediated by the negative emotions experienced by those who are bullied and partially moderated by features of the adolescent’s social environment and self. Regarding the latter, exposure to authoritative parenting and high self-control diminished the harmful effects of bullying victimization on self-harm and suicidal ideation. The article concludes by discussing the implications of these conclusions for future research and for policy efforts designed to reduce self-harm.  相似文献   
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