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   24955篇
  免费   363篇
  国内免费   14篇
教育   17862篇
科学研究   1968篇
各国文化   257篇
体育   2462篇
综合类   7篇
文化理论   248篇
信息传播   2528篇
  2021年   263篇
  2020年   400篇
  2019年   634篇
  2018年   838篇
  2017年   783篇
  2016年   779篇
  2015年   452篇
  2014年   605篇
  2013年   4515篇
  2012年   519篇
  2011年   569篇
  2010年   441篇
  2009年   475篇
  2008年   507篇
  2007年   468篇
  2006年   440篇
  2005年   369篇
  2004年   402篇
  2003年   323篇
  2002年   338篇
  2001年   475篇
  2000年   523篇
  1999年   442篇
  1998年   266篇
  1997年   262篇
  1996年   316篇
  1995年   259篇
  1994年   270篇
  1993年   228篇
  1992年   357篇
  1991年   378篇
  1990年   346篇
  1989年   374篇
  1988年   343篇
  1987年   330篇
  1986年   329篇
  1985年   384篇
  1984年   305篇
  1983年   307篇
  1982年   248篇
  1981年   251篇
  1980年   265篇
  1979年   356篇
  1978年   262篇
  1977年   239篇
  1976年   202篇
  1975年   186篇
  1974年   188篇
  1973年   185篇
  1971年   175篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
This study replicated a previous research project addressing connections between family-of-origin communication and organizational dissent expression. We predicted that family communication patterns (FCPs), specifically conversation and conformity orientations, would predict upward, lateral, and displaced dissent. As in the original study, significant findings emerged for upward dissent and conformity orientation. This replication study indicated family type as an inconsistent predictor of expressed dissent. Contrary to the original study, we found no evidence to support a connection between pluralistic family types and upward dissent. Finally, as an extension of the original study we analyzed effects of FCPs on displaced dissent, finding an inverse association with conversation orientation. Implications for future research are discussed.  相似文献   
142.
143.
The mere perception that news has given certain problems more coverage can lead the audience to assume that those problems are more important. Given that the news media, at times, obsesses over relatively trivial matters, and given that the audience is increasingly able to filter media exposure, it is worth asking what happens when audience members perceive that recent media coverage has not emphasized any very important problems. In such cases, audience members might assume that any problems facing the nation must not be particularly important. We explicate this attitude of political complacency, test whether perceived media agendas lacking important problems can influence it, and explore whether complacency helps explain political disengagement. We also explore whether these effects generalize beyond news, to new media gatekeepers such as Twitter. Two experiments tested effects of a perceived absence of important problems in recent news or Twitter content. In the case of news, but not Twitter, this increased complacency in both studies. Study 2 added a no-exposure control and found that effects on complacency were driven by the cueing of nonproblem stories, not by the absence of problem story cues. Both studies validated complacency as a predictor of political disengagement.  相似文献   
144.
Around 1960, the politics of the emerging media society in Sweden tended to fixate the formative functions of mass communication. The monopoly of public service broadcast media, press subsidies and new tendencies in film policy were some of the issues around which uncertainty prevailed. New methods to provide reliable data were sought by politicians, since empirical facts were required as arguments for an updated media policy. This article examines the different ways that the field of media studies was introduced in Sweden between 1960 and 1980. We argue that Swedish academic media studies departed from, and emerged within, a rather diffuse borderland between industry, politics and academia. The formation of national media research in Sweden can partly be seen as an effect of politicians and the media industry wanting to be better informed on issues such as media influence, media ownership and the habits and composition of the media audience.  相似文献   
145.
The purpose of this study is to find a theoretically grounded, practically applicable and useful granularity level of an algorithmically constructed publication-level classification of research publications (ACPLC). The level addressed is the level of research topics. The methodology we propose uses synthesis papers and their reference articles to construct a baseline classification. A dataset of about 31 million publications, and their mutual citations relations, is used to obtain several ACPLCs of different granularity. Each ACPLC is compared to the baseline classification and the best performing ACPLC is identified. The results of two case studies show that the topics of the cases are closely associated with different classes of the identified ACPLC, and that these classes tend to treat only one topic. Further, the class size variation is moderate, and only a small proportion of the publications belong to very small classes. For these reasons, we conclude that the proposed methodology is suitable to determine the topic granularity level of an ACPLC and that the ACPLC identified by this methodology is useful for bibliometric analyses.  相似文献   
146.
147.
148.
149.
With the rise of microfluidics for the past decade, there has come an ever more pressing need for a low-cost and rapid prototyping technology, especially for research and education purposes. In this article, we report a rapid prototyping process of chromed masks for various microfluidic applications. The process takes place out of a clean room, uses a commercially available video-projector, and can be completed in less than half an hour. We quantify the ranges of fields of view and of resolutions accessible through this video-projection system and report the fabrication of critical microfluidic components (junctions, straight channels, and curved channels). To exemplify the process, three common devices are produced using this method: a droplet generation device, a gradient generation device, and a neuro-engineering oriented device. The neuro-engineering oriented device is a compartmentalized microfluidic chip, and therefore, required the production and the precise alignment of two different masks.  相似文献   
150.
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