全文获取类型
收费全文 | 25621篇 |
免费 | 755篇 |
专业分类
各国政治 | 1049篇 |
工人农民 | 980篇 |
世界政治 | 2034篇 |
外交国际关系 | 850篇 |
法律 | 15488篇 |
中国共产党 | 2篇 |
中国政治 | 134篇 |
政治理论 | 5588篇 |
综合类 | 251篇 |
出版年
2020年 | 292篇 |
2019年 | 380篇 |
2018年 | 480篇 |
2017年 | 578篇 |
2016年 | 596篇 |
2015年 | 430篇 |
2014年 | 492篇 |
2013年 | 2497篇 |
2012年 | 573篇 |
2011年 | 650篇 |
2010年 | 522篇 |
2009年 | 603篇 |
2008年 | 655篇 |
2007年 | 683篇 |
2006年 | 652篇 |
2005年 | 590篇 |
2004年 | 593篇 |
2003年 | 617篇 |
2002年 | 579篇 |
2001年 | 995篇 |
2000年 | 886篇 |
1999年 | 727篇 |
1998年 | 422篇 |
1997年 | 347篇 |
1996年 | 321篇 |
1995年 | 318篇 |
1994年 | 349篇 |
1993年 | 324篇 |
1992年 | 510篇 |
1991年 | 558篇 |
1990年 | 515篇 |
1989年 | 534篇 |
1988年 | 500篇 |
1987年 | 508篇 |
1986年 | 551篇 |
1985年 | 532篇 |
1984年 | 470篇 |
1983年 | 491篇 |
1982年 | 370篇 |
1981年 | 332篇 |
1980年 | 276篇 |
1979年 | 365篇 |
1978年 | 222篇 |
1977年 | 230篇 |
1976年 | 206篇 |
1975年 | 180篇 |
1974年 | 206篇 |
1973年 | 191篇 |
1972年 | 169篇 |
1971年 | 154篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Pisani AR Schmeelk-Cone K Gunzler D Petrova M Goldston DB Tu X Wyman PA 《Journal of youth and adolescence》2012,41(10):1312-1324
Suicide is a leading cause of death among adolescents, many of whom fail to disclose suicide concerns to adults who might help. This study examined patterns and predictors of help-seeking behavior among adolescents who seriously considered suicide in the past year. 2,737 students (50.9?% female, 46.9?% male; racial distribution 79.5?% Caucasian, 11.9?% Hispanic/Latino, and 3.6?% Black/African-American) from 12 high schools in rural/underserviced communities were surveyed to assess serious suicide ideation (SI) in the past year, disclosure of SI to adults and peers, attempts to get help, attitudes about help-seeking, perceptions of school engagement, and coping support. Help-seeking was defined as both disclosing SI to an adult and perceiving oneself as seeking help. The relationship between adolescents' help-seeking disclosure and (1) help-seeking attitudes and (2) perceptions of social resources was examined among suicidal help-seeking youth, suicidal non-help-seeking youth, and non-suicidal youth. Of the 381 (14?%) students reporting SI, only 23?% told an adult, 29?% sought adult help, and 15?% did both. Suicidal help-seekers were similar to non-suicidal peers on all measures of help-seeking attitudes and social environment perceptions. Positive attitudes about help-seeking from adults at school, perceptions that adults would respond to suicide concerns, willingness to overcome peer secrecy requests, and greater coping support and engagement with the school were associated with students' increased disclosure of SI and help-seeking. This study supports prevention strategies that change student norms, attitudes and social environments to promote help-seeking among adolescents with SI. Promising intervention targets include increasing students' perceptions of the availability and capability of adults to help them, and strengthening students' understanding of how existing resources can help them cope. 相似文献
992.
Schwartz SJ Klimstra TA Luyckx K Hale WW Meeus WH 《Journal of youth and adolescence》2012,41(9):1208-1225
The longitudinal effects among self and identity processes, and between these processes and internalizing symptoms, are not well understood. As a result, the present study was designed to ascertain the over-time effects among identity commitment, reconsideration of commitments, and self-concept clarity, as well as to map the interplay of these self and identity processes with anxiety and depressive symptoms in early adolescence. A sample of 923 Dutch adolescents (mean age 12.4 years at Time 1; 49.3% female) participated at each of five annual assessments. Multivariate growth curve and cross-lagged panel models indicated that the association between self-concept clarity and commitment was bidirectional, that reconsideration occurs based on problems or dissatisfaction with self-concept clarity and with identity commitments, and that self-concept clarity (but not commitment or reconsideration) temporally precedes depressive and anxiety symptoms. Results are discussed in terms of the structure of the self-system and its associations with internalizing symptoms. 相似文献
993.
Research has linked the role of education to delinquency, but much of the focus has been on general population samples and
with little attention to demographic differences. Employing a cumulative disadvantage framework that integrates elements of
informal social control and labeling theories, this article examines whether academic achievement serves as a positive turning
point and re-directs juvenile delinquents away from subsequent offending. Attention is also given to race/sex contingencies.
Using a sample of 4,147 delinquents released from Florida correctional institutions (86% male, 57% non-White, average age
at release = 16.8 years), propensity score analysis yielded two findings: youth with above average academic achievement while
incarcerated were significantly more likely to return to school post-release, and youth with above average attendance in public
school were significantly less likely to be re-arrested in the 1-year post-release period. While the academic gains were pronounced
among African-American males, the preventive effects of school attendance are similar across race and sex, suggesting that
education can be a part of a larger prevention effort that assists juvenile delinquents in successful community re-entry. 相似文献
994.
Matthew E. Carnes S.J. 《拉美政治与社会》2014,56(2):93-114
Labor market dualism—the segmentation of workers between formal, legally protected employment and informal, unprotected status—has long drawn attention from scholars and policymakers in Latin America. This article argues that lasting patterns of economic and political segmentation of workers arose earlier in the region's history than has previously been understood, well before the classic “incorporation” period. Late‐nineteenth‐century practices for the recruitment and retention of workers shaped Latin America's first sets of labor laws, most notably those governing union organization and individual worker job stability. Subsequently, these first laws served as important templates for development, constraining and conditioning the labor codes adopted under mass‐based politics. Using historical data drawn from Chile, Peru, and Argentina, this article shows how differing recruitment practices and variation in the extension of effective suffrage rights and electoral participation shaped early legal labor market segmentation and inequality in Latin America. 相似文献
995.
Contrary to the predictions of “power sharing” to mitigate ethnic conflicts, multicultural rights recognition can actually increase the frequency of local postelectoral mobilizations. This article demonstrates that the adoption of an ethnic rights regime for electing local government representatives may actually increase conflict if these multicultural laws are not carefully circumscribed to avoid violating human rights. Focusing on the 1995 multicultural rights reforms in Oaxaca, it presents evidence that legal changes purportedly implemented to recognize indigenous rights actually increased postelectoral disputes due to conflicts between county seat communities and peripheral population hamlets over access to funding by the central government. Based on this finding, the article addresses normative implications of “power‐sharing” multiculturalism, recommending that multicultural laws be implemented only together with legal mechanisms to solve postelectoral disputes. 相似文献
996.
Christopher J. Ferguson Adolfo Garza Jessica Jerabeck Raul Ramos Mariza Galindo 《Journal of youth and adolescence》2013,42(1):109-122
The United States Supreme Court’s recent decision relating to violent video games revealed divisions within the scientific community about the potential for negative effects of such games as well as the need for more, higher quality research. Scholars also have debated the potential for violent games to have positive effects such as on visuospatial cognition or math ability. The current study sought to extend previous literature by using well-validated clinical outcome measures for relevant constructs, which have generally been lacking in past research. Cross-section data on aggression, visuospatial cognition, and math achievement were available for a sample of 333 (51.7 % female) mostly Hispanic youth (mean age = 12.76). Prospective 1-year data on aggression and school GPA were available for 143 (46.2 % female) of those youth. Results from both sets of analysis revealed that exposure to violent game had neither short-term nor long-term predictive influences on either positive or negative outcomes. A developmental analysis of the cross-sectional data revealed that results did not differ across age categories of older children, preadolescents or adolescents. Analysis of effect sizes largely ruled out Type II error as a possible explanation for null results. Suggestions for new directions in the field of video game research are proffered. 相似文献
997.
Nanette S. Danielsson Allison G. Harvey Shane MacDonald Markus Jansson-Fröjmark Steven J. Linton 《Journal of youth and adolescence》2013,42(8):1223-1233
Depression is a common and debilitating disorder in adolescence. Sleep disturbances and depression often co-occur with sleep disturbances frequently preceding depression. The current study investigated whether catastrophic worry, a potential cognitive vulnerability, mediates the relationship between adolescent sleep disturbances and depressive symptoms, as well as whether there are gender differences in this relationship. High school students, ages 16–18, n = 1,760, 49 % girls, completed annual health surveys including reports of sleep disturbance, catastrophic worry, and depressive symptoms. Sleep disturbances predicted depressive symptoms 1-year later. Catastrophic worry partially mediated the relationship. Girls reported more sleep disturbances, depressive symptoms, and catastrophic worry relative to boys. The results, however, were similar regardless of gender. Sleep disturbances and catastrophic worry may provide school nurses, psychologists, teachers, and parents with non-gender specific early indicators of risk for depression. Several potentially important practical implications, including suggestions for intervention and prevention programs, are highlighted. 相似文献
998.
Robert J. Constantine Ross Andel John Robst Eugenia M. Givens 《Journal of youth and adolescence》2013,42(8):1286-1298
This article identifies the arrest trajectories of youth from ages 12 through 24 years old and tests hypotheses derived from Moffitt’s developmental taxonomic theory of crime concerning the impact of various emotional disturbances on the specific trajectories of the youth involved. The study uses exclusively administrative data sets and includes a gender and racially diverse sample of 10,360 youth (30.7 % females) who were arrested at least once between ages 12 and 24 in the early 2000s. Latent class growth analysis was employed in order to identify distinct arrest trajectories of youth in the sample. Multinomial logistic regression was used to identify diagnostic and other characteristics associated with membership in the specific trajectories predicted by Moffitt’s theory. Five trajectory classes were identified, 3 of which were consistent with taxonomic theory including high and classic adolescence limited trajectory classes and a “snared adolescence limited class” described more recently by Moffitt. The distribution of youth among the 5 classes was very different for those with and without emotional disturbances. Youth with emotional disturbances in their late adolescent years were more likely to fall into the high arrest trajectory class and much less likely to fall into the low arrest trajectory class. Compared to youth without an emotional disturbance, youth with psychotic disorders were more than twice as likely to fall into the high as into the low arrest trajectory class. Youth with disruptive behavior disorders were more than twice as likely to fall into the high and intermediate classes as into the low trajectory class. Anxiety and depressive disorders were not associated with significantly greater likelihood of falling into any one of the trajectory classes. Youth in the snared adolescence limited class were more likely than those in the classic adolescence limited class to be male, black versus white and in the foster care enrollment category lending some support to Moffitt’s conceptualization of this class as an adolescence limited class composed of youth who are snared by involvement in the criminal justice and or social services systems. Implications of these results for public policy and the study of adolescence are discussed. 相似文献
999.
Debra J. Rosenthal 《Women's Studies: An inter-disciplinary journal》2013,42(2):221-245
A reformer most of her life, Lydia Maria Child advanced the rights of women, Native Americans, and African Americans in such works as History of the Condition of Women in Various Ages and Nations (1835), Hobomok (1823), and An Appeal in Favor of That Class of Americans Called Africans (1833). 相似文献
1000.
Noelle M. Hurd Fatima A. Varner Stephanie J. Rowley 《Journal of youth and adolescence》2013,42(10):1583-1595
Positive relationships with parents and nonparental adults have the potential to bolster Black adolescents’ socio-emotional well-being. Though each type of intergenerational relationship has been linked to more positive youth outcomes, few studies have examined the interactive influences of parenting and natural mentoring relationships on the socio-emotional development of Black youth. In the current study, we examined associations between involved-vigilant parenting and the psychological well-being and social skills of Black early adolescents (n = 259; 58 % female; mean age = 13.56, SD = .96) across types of natural mentoring relationships. Using K-means cluster analysis, we identified two types of mentoring relationships (less connected and more connected) based on relationship length, involvement, closeness, and frequency of contact. Youth with more connected mentoring relationships (n = 123) had higher psychological well-being and social skills than youth with no mentor (n = 64) or less connected mentors (n = 72). Youth without a natural mentor and youth with less connected mentors did not differ in their levels of social skills or psychological well-being. Structural equation modeling was conducted to determine if associations between involved-vigilant parenting and youths’ psychological well-being and social skills varied among youth with a more connected mentoring relationship in comparison to youth without a mentor or with a less connected mentor, controlling for participants’ gender, age, school, and parental education. The positive associations between involved-vigilant parenting and adolescents’ psychological well-being and social skills were weaker among adolescents with a more connected mentoring relationship in comparison to their peers without or with a less connected mentoring relationship. These results suggest that youth may be more strongly influenced by involved-vigilant parenting in the absence of a strongly connected natural mentoring relationship. 相似文献