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   19158篇
  免费   252篇
  国内免费   23篇
教育   13235篇
科学研究   1707篇
各国文化   247篇
体育   1877篇
综合类   23篇
文化理论   152篇
信息传播   2192篇
  2021年   141篇
  2020年   265篇
  2019年   405篇
  2018年   470篇
  2017年   539篇
  2016年   516篇
  2015年   331篇
  2014年   425篇
  2013年   3737篇
  2012年   356篇
  2011年   420篇
  2010年   345篇
  2009年   381篇
  2008年   384篇
  2007年   349篇
  2006年   325篇
  2005年   317篇
  2004年   558篇
  2003年   434篇
  2002年   473篇
  2001年   315篇
  2000年   326篇
  1999年   276篇
  1998年   144篇
  1997年   178篇
  1996年   201篇
  1995年   188篇
  1994年   176篇
  1993年   174篇
  1992年   231篇
  1991年   247篇
  1990年   217篇
  1989年   260篇
  1988年   208篇
  1987年   258篇
  1986年   222篇
  1985年   288篇
  1984年   241篇
  1983年   227篇
  1982年   195篇
  1981年   172篇
  1980年   143篇
  1979年   217篇
  1978年   190篇
  1977年   164篇
  1976年   167篇
  1975年   141篇
  1974年   144篇
  1973年   123篇
  1971年   133篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
141.
PURPOSE: This study describes the system architecture and user acceptance of a suite of programs that deliver information about newly updated library resources to clinicians' personal digital assistants (PDAs). DESCRIPTION: Participants received headlines delivered to their PDAs alerting them to new books, National Guideline Clearinghouse guidelines, Cochrane Reviews, and National Institutes of Health (NIH) Clinical Alerts, as well as updated content in UpToDate, Harrison's Online, Scientific American Medicine, and Clinical Evidence. Participants could request additional information for any of the headlines, and the information was delivered via e-mail during their next synchronization. Participants completed a survey at the conclusion of the study to gauge their opinions about the service. RESULTS/OUTCOME: Of the 816 headlines delivered to the 16 study participants' PDAs during the project, Scientific American Medicine generated the highest proportion of headline requests at 35%. Most users of the PDA Alerts software reported that they learned about new medical developments sooner than they otherwise would have, and half reported that they learned about developments that they would not have heard about at all. While some users liked the PDA platform for receiving headlines, it seemed that a Web database that allowed tailored searches and alerts could be configured to satisfy both PDA-oriented and e-mail-oriented users.  相似文献   
142.
The Cross-Language Evaluation Forum has encouraged research in text retrieval methods for numerous European languages and has developed durable test suites that allow language-specific techniques to be investigated and compared. The labor associated with crafting a retrieval system that takes advantage of sophisticated linguistic methods is daunting. We examine whether language-neutral methods can achieve accuracy comparable to language-specific methods with less concomitant software complexity. Using the CLEF 2002 test set we demonstrate empirically how overlapping character n-gram tokenization can provide retrieval accuracy that rivals the best current language-specific approaches for European languages. We show that n = 4 is a good choice for those languages, and document the increased storage and time requirements of the technique. We report on the benefits of and challenges posed by n-grams, and explain peculiarities attendant to bilingual retrieval. Our findings demonstrate clearly that accuracy using n-gram indexing rivals or exceeds accuracy using unnormalized words, for both monolingual and bilingual retrieval.  相似文献   
143.
Hayes, Glynn, and Shanahan (2005) defined self-censorship asthe withholding of one’s opinion around an audience perceivedto disagree with that opinion. They argued that people differin their willingness to self-censor and introduced an 8-itemself-report instrument, the Willingness to Self-Censor scale,to measure this individual difference. The results of an experimentalstudy presented here provide further evidence of the constructvalidity of the scale. Each participant in the study was presentedwith a hypothetical scenario that contained information suggestinga group of people the participant was conversing with abouta controversial topic held opinions that were either uniformlysimilar to or different from the participant’s own opinion.Four weeks prior, each participant had responded to the Willingnessto Self-Censor scale and a measure of dispositional shyness.As expected, the manipulation of the climate of opinion affectedwillingness to express an opinion to the group, but more soamong those who scored relatively high on the Willingness toSelf-Censor scale. These results support the notion that somepeople rely on information about the climate of opinion moreso than do others when they decide whether or not to voice theiropinion publicly, and they suggest that the Willingness to Self-Censorscale measures this individual difference.  相似文献   
144.
Organizational communication scholars are increasingly called upon to use theoretical knowledge to address problematic processes in public institutions. This article reports a process improvement project focused on a university conflict of interest (COI) policy as an example of how scholars can engage theory to improve ongoing policy processes. The project team included communication scholars and research administration staff who designed, implemented, and evaluated the mixed-methods project guided by structurating activity theory. Baseline survey results were used to design the process improvement project. Results of the follow-up survey indicate that researchers who participated in some aspect of the process improvement project (i.e. attending a policy café, using the redesigned website, or reading the new Quick Reference Guide) reported higher levels of policy communication and knowledge and more positive attitudes toward the COI policy than researchers who had not engaged with process improvement efforts. We offer theoretical and practical implications of results for organizational communication scholars and practitioners.  相似文献   
145.
Academic libraries are increasingly seeking ways to demonstrate their impact on student learning. Acknowledgments - formal statements of indebtedness – in graduate theses and dissertations provide a rather unexplored area for demonstrating impact of the academic library on student learning. This study uses quantitative and qualitative methods to characterize acknowledgments of the Texas A&M University Libraries (TAMU Libraries) in theses and dissertations, both overall and for three disciplines specifically: civil engineering, geography, and history. This study also searched for mentions of the TAMU Libraries throughout the entire body of theses and dissertations. Overall, acknowledgments to the TAMU Libraries in theses and dissertations were less than 1%, though acknowledgments were found in all three disciplines with over a quarter of the history theses and dissertations containing an acknowledgment to libraries. There was no statistically significant difference found between the numbers of acknowledgments in theses versus dissertations. Acknowledgments to the TAMU Libraries were found in the theses and dissertations of 28 different departments. Mentions to the TAMU Libraries – not necessarily a formal acknowledgment – were found throughout the text of theses and dissertations with most concentrated in the acknowledgment, method, and bibliography sections.  相似文献   
146.
ABSTRACT

Social media is a powerful tool for building an online presence, but it asks a lot. While it affords plentiful opportunities for professional development and networking, building a professional brand in an online space is not without its drawbacks and risks. By working from a set of actionable principles and benchmarks, users can minimize frustrations and setbacks to build a useful professional presence, all while imbuing the web with the tenets of good information stewardship.  相似文献   
147.
This paper characterizes the methodological foundations of national standardization in the Russian Federation, in particular in the library and information field. The activities of Technical Standardization Committee 191 Scientific and Technical Information, Librarianship, and Publishing are reported.  相似文献   
148.
A rich literature exists reinforcing the notion that both perceived and received social support has stress ameliorating and protective benefits both psychologically and physiologically. However, recent literature suggests that excessive dyadic negative problem talk about an issue, a phenomenon labeled co-rumination, may reverse much of the beneficial effects of social support. Healthy young adults participated in a laboratory research study exploring the associations between co-rumination and immune system inflammatory response. Partial correlations indicated a positive association between co-rumination and C-reactive protein and a negative association between co-rumination and interleukin-6 after controlling for stress, anxiety, and temperature. Discussion focuses on the means by which co-rumination may lead to negative health outcomes.  相似文献   
149.
This article explores people’s susceptibility to political deception. Participants watched a news interview in which a politician either answered all the questions or deceptively evaded a question. In Study 1 (n = 202), deception is perceived through the dodge being irrelevant for voters who do not identify with the politician. In Study 2 (n = 618), partisan voters consider the politician more deceptive, and acting more deceptively, when the politician has their opposing party affiliation, independent of whether he dodges. When the politician shares their party identification, voters identify with the politician more and consider his responses more relevant. Findings are consistent with theoretical positions of identification, the cooperative principle, and social identity.  相似文献   
150.
This introductory article to the combined special issue of Journalism Studies and Journalism Practice provides an overview of some of the key contemporary approaches to studying journalism and social order. It argues the need to step beyond a functionalist framework when considering the news media’s central role in shaping social connections, community and cohesion. To advance our understandings of social order, our paper suggests a greater emphasis of the significance of journalism’s relationship to the wider social sphere along with three other key considerations, including (1) a critical focus on the relationship between media, politics and social order, especially in defining and/or negotiating “anti-social” practices and social disintegration; (2) a more refined focus on the “imagined” and geographic boundaries of news audiences in digital spaces; and (3) the changing relationship to norms and conventions of journalism practice from trust and legitimacy to the role of journalists as arbiters and connectors across social spaces.  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