全文获取类型
收费全文 | 17640篇 |
免费 | 241篇 |
国内免费 | 11篇 |
专业分类
教育 | 12921篇 |
科学研究 | 1448篇 |
各国文化 | 147篇 |
体育 | 1439篇 |
综合类 | 8篇 |
文化理论 | 123篇 |
信息传播 | 1806篇 |
出版年
2021年 | 138篇 |
2020年 | 214篇 |
2019年 | 359篇 |
2018年 | 477篇 |
2017年 | 500篇 |
2016年 | 451篇 |
2015年 | 287篇 |
2014年 | 400篇 |
2013年 | 3438篇 |
2012年 | 406篇 |
2011年 | 458篇 |
2010年 | 307篇 |
2009年 | 310篇 |
2008年 | 433篇 |
2007年 | 338篇 |
2006年 | 397篇 |
2005年 | 291篇 |
2004年 | 269篇 |
2003年 | 248篇 |
2002年 | 288篇 |
2001年 | 370篇 |
2000年 | 348篇 |
1999年 | 318篇 |
1998年 | 172篇 |
1997年 | 198篇 |
1996年 | 226篇 |
1995年 | 221篇 |
1994年 | 184篇 |
1993年 | 193篇 |
1992年 | 279篇 |
1991年 | 245篇 |
1990年 | 250篇 |
1989年 | 274篇 |
1988年 | 272篇 |
1987年 | 228篇 |
1986年 | 229篇 |
1985年 | 238篇 |
1984年 | 210篇 |
1983年 | 244篇 |
1982年 | 191篇 |
1981年 | 186篇 |
1980年 | 182篇 |
1979年 | 247篇 |
1978年 | 199篇 |
1977年 | 176篇 |
1976年 | 168篇 |
1975年 | 141篇 |
1974年 | 138篇 |
1973年 | 140篇 |
1971年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
E Diane Johnson Paul E Pancoast Joyce A Mitchell Chi-Ren Shyu 《Journal of the Medical Library Association》2004,92(4):438-444
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
72.
Paul J Bracke 《Journal of the Medical Library Association》2004,92(4):421-428
OBJECTIVES: This paper explores the potential of multinomial logistic regression analysis to perform Web usage mining for an academic health sciences library Website. METHODS: Usage of database-driven resource gateway pages was logged for a six-month period, including information about users' network addresses, referring uniform resource locators (URLs), and types of resource accessed. RESULTS: It was found that referring URL did vary significantly by two factors: whether a user was on-campus and what type of resource was accessed. CONCLUSIONS: Although the data available for analysis are limited by the nature of the Web and concerns for privacy, this method demonstrates the potential for gaining insight into Web usage that supplements Web log analysis. It can be used to improve the design of static and dynamic Websites today and could be used in the design of more advanced Web systems in the future. 相似文献
73.
74.
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
75.
This article reports on a large‐scale international survey of authors' perception and experience of the journals system conducted by ciber in association with National Opinion Polls (NOP). It explores the factors that inform authors' decisions where to publish and, in particular, which groups of readers they perceive to be most important. It probes readership behaviour and the values that underlie authors' attitudes towards copyright and emerging business models, notably open access. It is concluded that many aspects of author behaviour are highly conservative and that a significant shift towards open access is, in the short to medium term, highly unlikely. 相似文献
76.
77.
Analyzing 219 blog posts from 52 self-employed women lifestyle bloggers in North America, this study shows how these digital professionals navigate tensions and communicatively constitute work flexibility. In their narratives, women bloggers employed tension management approaches such as reframing, continual connections, and reflective practice in response to tensions in enacting temporal–spatial, identity, and financial flexibility. Specifically, women followed oxymoronic constructions – disciplined freedom, branded authenticity, and dependable independence – to embrace and transform competing poles of fluidity?structure, authenticity?marketability, and independence?interconnection. Expanding work–life research to the self-employed digital labor context, this study responds to recent calls to uncover more-than tension management strategies in empirical settings and contributes to a tension-centered, contextual, and processual analysis of workplace flexibility construction. 相似文献
78.
Leanne K. Knobloch Erin D. Basinger Jennifer A. Theiss 《Journal of Applied Communication Research》2018,46(1):52-73
The transition from deployment to reintegration can be stressful for returning military personnel and at-home partners, and support plays a key role in their ability to transition effectively. We draw on relational turbulence theory to advance predictions about how parameters of the relationship between returning service members and at-home partners predict their perceptions of their partner’s support during the post-deployment transition. We surveyed 235 individuals (117 returning service members, 118 at-home partners) who had experienced the transition within the past 6 months. Findings consistent with the theory indicated that relational turbulence partially mediated the negative associations that relational uncertainty and interference from a partner shared with partner support. Partner uncertainty was a direct negative predictor of partner support as well. We consider how these results extend theory, research, and practice. 相似文献
79.
Heather E. Canary Kris May Marc D. Rinehart Jahn B. Barlow 《Journal of Applied Communication Research》2018,46(2):202-222
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
80.
This paper explores the information nature of culture. It is represented as an extragenetic and nonorganizational information process and system. Information is regarded as a universal property of matter that is essentially associated with development processes and realizes various forms and ways of storage and circulation at various development stages of global evolution. The socio-cultural principle of exogenous accumulation, transmission, and transformation of information is analyzed in the context of the continuing growth of the information content of material systems on the superhighway of global-universal evolution. It is noted that the information concept of culture evolves into a new area of cultural studies, that is information and cultural studies, advancing our understanding of the nature of culture and cultural genesis. 相似文献