全文获取类型
收费全文 | 22495篇 |
免费 | 680篇 |
专业分类
各国政治 | 1004篇 |
工人农民 | 838篇 |
世界政治 | 1885篇 |
外交国际关系 | 795篇 |
法律 | 13320篇 |
中国共产党 | 2篇 |
中国政治 | 109篇 |
政治理论 | 4993篇 |
综合类 | 229篇 |
出版年
2020年 | 273篇 |
2019年 | 335篇 |
2018年 | 450篇 |
2017年 | 494篇 |
2016年 | 527篇 |
2015年 | 376篇 |
2014年 | 426篇 |
2013年 | 2302篇 |
2012年 | 523篇 |
2011年 | 564篇 |
2010年 | 468篇 |
2009年 | 511篇 |
2008年 | 571篇 |
2007年 | 589篇 |
2006年 | 596篇 |
2005年 | 512篇 |
2004年 | 512篇 |
2003年 | 529篇 |
2002年 | 505篇 |
2001年 | 813篇 |
2000年 | 744篇 |
1999年 | 617篇 |
1998年 | 363篇 |
1997年 | 320篇 |
1996年 | 260篇 |
1995年 | 269篇 |
1994年 | 307篇 |
1993年 | 286篇 |
1992年 | 428篇 |
1991年 | 482篇 |
1990年 | 424篇 |
1989年 | 455篇 |
1988年 | 415篇 |
1987年 | 455篇 |
1986年 | 452篇 |
1985年 | 448篇 |
1984年 | 400篇 |
1983年 | 429篇 |
1982年 | 338篇 |
1981年 | 316篇 |
1980年 | 250篇 |
1979年 | 321篇 |
1978年 | 229篇 |
1977年 | 192篇 |
1976年 | 188篇 |
1975年 | 168篇 |
1974年 | 193篇 |
1973年 | 177篇 |
1972年 | 151篇 |
1971年 | 134篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
Hyeouk Chris Hahm Yoona Lee Al Ozonoff Michael J. Van Wert 《Journal of youth and adolescence》2010,39(5):528-540
The purpose of this study was to investigate how different types of child maltreatment, independently and collectively, impact
a wide range of risk behaviors that fall into three domains: sexual risk behaviors, delinquency, and suicidality. Cumulative
classification and Expanded Hierarchical Type (EHT) classification approaches were used to categorize various types of maltreatment.
Data were derived from Wave III of the National Longitudinal Study of Adolescent Health (Add Health). Our sample consisted
of White, Black, Hispanic, and Asian females ages 18 to 27 (n = 7,576). Experiencing different kinds of maltreatment during childhood led to an extensive range of risk behaviors within
the three identified domains. Women experiencing sexual abuse plus other maltreatment types had the poorest outcomes in all
three domains. These findings illustrate that it may no longer be appropriate to assume that all types of maltreatment are
equivalent in their potential contribution to negative developmental sequelae. 相似文献
962.
Tracy M. Scull Janis B. Kupersmidt Alison E. Parker Kristen C. Elmore Jessica W. Benson 《Journal of youth and adolescence》2010,39(9):981-998
Two cross-sectional studies investigated media influences on adolescents’ substance use and intentions to use substances in
the context of exposure to parental and peer risk and protective factors. A total of 729 middle school students (n = 351, 59% female in Study 1; n = 378, 43% female in Study 2) completed self-report questionnaires. The sample in Study 1 was primarily African-American
(52%) and the sample in Study 2 was primarily Caucasian (63%). Across the two studies, blocks of media-related cognitions
made unique contributions to the prediction of adolescents’ current substance use and intentions to use substances in the
future above and beyond self-reported peer and parental influences. Specifically, identification with and perceived similarity
to media messages were positively associated with adolescents’ current substance use and intentions to use substances in the
future, and critical thinking about media messages and media message deconstruction skills were negatively associated with
adolescents’ intention to use substances in the future. Further, peer influence variables (e.g., peer pressure, social norms,
peer substance use) acted as risk factors, and for the most part, parental influence variables (e.g., parental pressure to
not use, perceived parental reaction) acted as protective factors. These findings highlight the importance of developing an
increased understanding of the role of media messages and media literacy education in the prevention of substance use behaviors
in adolescence. 相似文献
963.
Heidi E. Grunwald Brian Lockwood Philip W. Harris Jeremy Mennis 《Journal of youth and adolescence》2010,39(9):1067-1079
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
964.
Michael J. Cleveland Mark E. Feinberg Mark T. Greenberg 《Journal of youth and adolescence》2010,39(2):114-126
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
965.
Oscar W. Gabriel Ulf Bohmann Daniel Gaus Emanuel Richter Annika Frisch Helga Haftendorn Dirk Berg-Schlosser Frank Bönker Dennis-Jonathan Mann Christian Tuschhoff Karsten Schmitz Jared Sonnicksen Heinrich Pehle Marco Schäferhoff Wilhelm Bleek Jürgen Petersen 《Politische Vierteljahresschrift》2009,50(3):646-690
966.
The riskiness of state employee pension plan portfolios varies across states. We investigate whether this variation is related to how public employees and taxpayers share actuarial surpluses of pension accounts. We focus on two determinants of a plan’s asset mix: the relative influence of public employees to taxpayers; and whether a surplus-sharing contract is specified. Our theoretical model demonstrates that the effect of public employee influence on the asset mix is ambiguous. Our empirical results corroborate this complex theoretical result. In our theoretical and empirical analyses, if a surplus sharing rule is specified, plans adopt a more aggressive investment allocation. 相似文献
967.
968.
Klaus-Gert Lutterbeck Armin Schäfer Andreas Heyer Christian Kaiser Helga Haftendorn Sandra Seubert Christian Bala Ralf J. Leiteritz Frank Dietrich Christian Brütt Christian Reisinger Alexander Warkotsch Mandana Biegi Burkhard Conrad Christian Stecker 《Politische Vierteljahresschrift》2009,50(2):327-363
Ohne Zusammenfassung 相似文献
969.
The review essay takes stock of the last decade of decentralisation and regionalisation research in Central and South Eastern Europe. Classifying the existing scholarship with regard to its focus of analysis, its explanatory programme, and methodological predilections, we suggest to distinguish three different agendas: system transformation, EU conditionality and subnational governance. We argue that scholarly interest in regionalisation and decentralisation issues from the perspective of state transformation or Europeanisation is vanishing. Instead, we witness the emergence of a subnational governance approach which is rooted in comparative politics and policy analysis. The debate about decentralisation and regionalisation in CEEC is thus in a process of “normalising” and converging with the Western European subnational political discourse. 相似文献
970.
Michael J. Ensley 《Public Choice》2009,138(1-2):221-238
Individual citizens are the largest source of contributions for congressional candidates in the United States. This paper investigates if and how fundraising from this source is related to the ideological positions of candidates. Specifically, we ask whether the amount of contributions depends on: (1) the extremity of candidate ideology; and (2) the level of candidate divergence in the same race. These results have important implications for candidate positioning strategies, as well as for evaluating the effects of recent campaign finance reforms. 相似文献