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   9402篇
  免费   320篇
各国政治   647篇
工人农民   398篇
世界政治   737篇
外交国际关系   392篇
法律   5389篇
中国共产党   2篇
中国政治   146篇
政治理论   1920篇
综合类   91篇
  2020年   123篇
  2019年   148篇
  2018年   208篇
  2017年   231篇
  2016年   238篇
  2015年   203篇
  2014年   207篇
  2013年   1153篇
  2012年   249篇
  2011年   325篇
  2010年   232篇
  2009年   254篇
  2008年   259篇
  2007年   245篇
  2006年   237篇
  2005年   206篇
  2004年   232篇
  2003年   250篇
  2002年   176篇
  2001年   363篇
  2000年   336篇
  1999年   297篇
  1998年   149篇
  1997年   110篇
  1996年   115篇
  1995年   101篇
  1994年   115篇
  1993年   104篇
  1992年   161篇
  1991年   158篇
  1990年   155篇
  1989年   141篇
  1988年   163篇
  1987年   160篇
  1986年   164篇
  1985年   149篇
  1984年   151篇
  1983年   161篇
  1982年   96篇
  1981年   72篇
  1980年   80篇
  1979年   104篇
  1978年   80篇
  1977年   69篇
  1976年   70篇
  1975年   62篇
  1974年   51篇
  1972年   53篇
  1971年   54篇
  1969年   54篇
排序方式: 共有9722条查询结果,搜索用时 15 毫秒
961.
There is mounting evidence that HIV infection among adolescents is increasing, particularly among minorities and inner-city youths involved in certain high-risk activities, such as multiple sex partners and intravenous drug use. Interviews conducted “on the street” with 611 seriously delinquent male and female adolescents (ages 12–17) included questions about their involvement in prostitution, intravenous drug use, and sex-for-crack exchanges. Findings included high percentages of youths engaged in these HIV-risk activities and a consistent association between all of them and greater illicit drug use. This would suggest that these risk behaviors may be surprisingly prevalent among some inner-city adolescent groups. Special AIDS prevention/intervention targeting these groups is warranted and urgently needed. Drug treatment should be a central focus of such programs.  相似文献   
962.
Interpretation of unusual wounds caused by firearms.   总被引:1,自引:0,他引:1  
The interpretation of the range of fire of gunshot wounds requires coordination of information and observations from the autopsy surgeon, scene investigator, and laboratory analyst. Opinions based on incomplete information often lead to misinterpretation of the wound. The effects of interposed targets such as clothing, windows, and body parts are discussed. Case examples are given for interposed targets that cause confusing patterns and even lead to misidentification of the points of entrance and exit of the projectile in the body. The splitting of tissue in areas of bony prominence can be mistaken for evidence of discharge of a firearm at close range.  相似文献   
963.
The simultaneous occurrence of cerebral hemorrhage and hemopericardium due to the rupture of a dissecting aneurysm has not been previously reported. We describe an autopsy case of a 45-year-old man with hypertension who died suddenly following both of these conditions. He had been treated for hypertension; the finding of arteriolar nephrosclerosis supported the existence of the disease. Because rupture of the aorta invariably causes a marked fall in blood pressure, the occurrence of cerebral hemorrhage following hemopericardium is highly unlikely. Thus, we presume that rupture of the aorta occurred after the cerebral hemorrhage.  相似文献   
964.
The alleles present at the HLA DQ alpha locus may be typed by either allele specific oligonucleotide (ASO) probing or by restriction mapping, referred to here as amplification restriction fragment polymorphism (ARFP) analysis. ASO typing relies upon hybridization principles, whereas ARFP typing relies upon restriction site analysis. Dot-blot ASO typings which are of doubtful interpretation may be directly checked by ARFP analysis. Aliquots of the PCR products amplified using the commercial Amplitype HLA DQ alpha system are digested with suitable restriction endonucleases. Electrophoresis, blotting and detection of biotin-labelled restriction fragments provides a sensitive and robust typing method suited to forensic analysis.  相似文献   
965.
966.
We show that Brazilian voters strongly sanction malfeasant mayors when presented with hypothetical scenarios but take no action when given the same information about their own mayor. Partnering with the State Accounts Court of Pernambuco, we conducted a field experiment during the 2016 municipal elections in which the treatment group received information about official wrongdoing by their mayor. The treatment has no effect on self‐reported voting behavior after the election, yet when informing about malfeasance in the context of a vignette experiment, we are able to replicate the strong negative effect found in prior studies. We argue that voters' behavior in the abstract reflects the comparatively strong norm against corruption in Brazil. Yet on Election Day, their behavior is constrained by factors such as attitudes toward local political dynasties and the greater salience of more pressing concerns like employment and health services.  相似文献   
967.
Political Behavior - Much of the gender gap literature focuses on women’s greater average liberalism relative to men. This approach masks considerable heterogeneity in political identity and...  相似文献   
968.
We evaluate the cost‐effectiveness of two early childhood interventions that use instructional coaching and parent coaching as levers for improvement. The study design allows us to compare the individual effects of each intervention as well as their combined effect on student outcomes. We find that teachers receiving instructional coaching improve their use of evidence‐based instructional practices, while families receiving parent coaching show increases in numerous responsive parenting behaviors associated with positive child outcomes. Both interventions demonstrate positive impacts on students, but only parent coaching shows statistically significant effects across a range of student outcomes. Instructional coaching alone is substantially less costly and may therefore be the most cost‐effective of the three treatment conditions; however, small sample sizes limit our ability to reach definitive conclusions. Policy simulations suggest that implementing these interventions could raise the overall cost‐effectiveness of Head Start by at least 16 percent.  相似文献   
969.
Over the past decade, directional drilling and hydraulic fracturing enabled an unconventional oil and gas extraction (UOGE) boom in many regions of the United States, including parts of Pennsylvania. This revolution has created serious concerns about the capability of existing institutions to govern important societal outcomes associated with UOGE. We present a conceptual framework for assessing key societal outcomes influenced by UOGE governance. In applying this framework to Pennsylvania, we discern certain institutional strengths that have allowed the Commonwealth to reap appreciable short‐term economic growth from rich resource endowments. We also find, however, that several institutional weaknesses have allowed costs externalized to the environment, public health, and community integrity to offset some proportion of those economic benefits. Likewise, we find that governance of UOGE in Pennsylvania has contributed to a bifurcated sociopolitical landscape wherein adversarial coalitions dispute the legitimacy of the industry and its governance.  相似文献   
970.
Journal of Youth and Adolescence - Despite the centrality of dating relationships for teens, it is unclear whether the influence of romantic partners’ alcohol use on adolescents’...  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