全文获取类型
收费全文 | 23953篇 |
免费 | 424篇 |
国内免费 | 15篇 |
专业分类
教育 | 17281篇 |
科学研究 | 2062篇 |
各国文化 | 239篇 |
体育 | 1937篇 |
综合类 | 15篇 |
文化理论 | 178篇 |
信息传播 | 2680篇 |
出版年
2022年 | 183篇 |
2021年 | 278篇 |
2020年 | 399篇 |
2019年 | 628篇 |
2018年 | 888篇 |
2017年 | 856篇 |
2016年 | 758篇 |
2015年 | 446篇 |
2014年 | 693篇 |
2013年 | 4717篇 |
2012年 | 675篇 |
2011年 | 674篇 |
2010年 | 495篇 |
2009年 | 511篇 |
2008年 | 570篇 |
2007年 | 510篇 |
2006年 | 452篇 |
2005年 | 441篇 |
2004年 | 386篇 |
2003年 | 369篇 |
2002年 | 355篇 |
2001年 | 490篇 |
2000年 | 408篇 |
1999年 | 373篇 |
1998年 | 217篇 |
1997年 | 219篇 |
1996年 | 254篇 |
1995年 | 247篇 |
1994年 | 187篇 |
1993年 | 208篇 |
1992年 | 326篇 |
1991年 | 311篇 |
1990年 | 305篇 |
1989年 | 303篇 |
1988年 | 264篇 |
1987年 | 308篇 |
1986年 | 270篇 |
1985年 | 308篇 |
1984年 | 251篇 |
1983年 | 216篇 |
1982年 | 196篇 |
1981年 | 167篇 |
1980年 | 158篇 |
1979年 | 263篇 |
1978年 | 187篇 |
1977年 | 172篇 |
1976年 | 157篇 |
1975年 | 146篇 |
1974年 | 147篇 |
1971年 | 145篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Analysis of the urban/rural broadband divide in Canada: Using GIS in planning terrestrial wireless deployment 总被引:3,自引:0,他引:3
M. Sawada Daniel Cossette Barry Wellar Tolga Kurt 《Government Information Quarterly》2006,23(3-4):454
Millions of Canadians residing in Canada's northern, isolated, rural, and remote communities do not have broadband Internet access. This situation has led to a national “broadband divide.” That is, the deployment of wireline broadband is very limited in Canada's northern, isolated, rural, and remote areas because of the significant expense of installation and maintenance of the wired infrastructure needed to reach dwellings in these locations.Terrestrial broadband wireless technology, on the other hand, does not entail the same kind of physical infrastructure. As a result, there are dramatic changes in how spatial considerations affect the provision of broadband Internet services (BIS) to areas beyond the urban zone. In particular, the spatial question is now focused on assessing the capacity for different technological solutions to reach profitable population bases, and brings to the forefront organizations that are developing non-line-of-sight (NLOS) technologies that would permit wireless Internet access over much greater distances than current solutions.We begin this paper by establishing the importance of broadband connectivity to Canada's northern, isolated, rural, and remote communities. This discussion comments on the role of the Government of Canada in the provision of broadband connectivity to residents of these communities, and outlines the current regulatory issues that govern wireless services and policy formulation.The second part of the paper illustrates the use of geographic information system (GIS) approaches in the study of wireless broadband planning and deployment. Case study findings suggest that GIS applications can make a significant contribution to the analysis of wireless deployment planning, to the understanding of the relationships between wireless signal sources and consumers, and to the spatial configuration of terrestrial wireless broadband networks. We conclude the paper by discussing how the GIS approach employed could be used to inform the public policy process with regard to increasing access to broadband Internet services in all regions of the country, and thereby providing the opportunity for all Canadians, regardless of location, to fully participate in the Information Society. 相似文献
102.
103.
Thanh Tin Tang Nick Craswell David Hawking Kathy Griffiths Helen Christensen 《Information Retrieval》2006,9(2):207-225
When searching for health information, results quality can be judged against available scientific evidence: Do search engines return advice consistent with evidence based medicine? We compared the performance of domain-specific health and depression search engines against a general-purpose engine (Google) on both relevance of results and quality of advice. Over 101 queries, to which the term ‘depression’ was added if not already present, Google returned more relevant results than those of the domain-specific engines. However, over the 50 treatment-related queries, Google returned 70 pages recommending for or against a well studied treatment, of which 19 strongly disagreed with the scientific evidence. A domain-specific index of 4 sites selected by domain experts was only wrong in 5 of 50 recommendations. Analysis suggests a tension between relevance and quality. Indexing more pages can give a greater number of relevant results, but selective inclusion can give better quality. 相似文献
104.
Lynn M. Harter 《Journal of Applied Communication Research》2004,32(2):89-118
This study explores how members of the Nebraska Cooperative Council and its constituent producer-owned cooperatives understand and enact democratic ideologies, drawing particular attention to how emergent contradictions and tensions are experienced and managed. The Council serves as a particularly rich context in which to explore traditionally feminine ways of organizing (i.e., cooperative enactment) in a historically male-dominated arena (i.e., agriculture). The dialectic of independence and solidarity became a revealing prism through which to make sense of how members enact cooperative life. This dialectic manifests itself in the discourse of cooperative life as members struggle to manage tensions between efficiency and participation, equality and equity, and the paradox of agency. Communication theorizing about gendered organizing and the history of American agrarianism is used to explore intersections between the social construction of masculinity(s), the agrarian frontier myth, and tensions embedded in the discourse of cooperative organizing. 相似文献
105.
Diane M. Martin 《Journal of Applied Communication Research》2004,32(2):147-170
Women in middle management continue to face multiple paradoxes arising from their structural and gendered locations that add to the uncertainty of negotiating organizational life. Investigating the lived experiences of women middle managers can illuminate the constraints and paradoxes endemic to organizing, for such experiences foreground tensions at the intersection of structure, identity, agency, and power. Specifically, this contextual investigation of conversational humor explores links between organizational status, gender, and paradox. In so doing, it demonstrates how women can use humor to negotiate managerial identities and to navigate organizational life. This study uncovers nuanced and important communication tactics of middle management women. This study also reveals the value of investigating the complex convergence of humor, gender, and organizational communication theory. 相似文献
106.
Mary M. Meares John G. Oetzel Annette Torres Denise Derkacs Tamar Ginossar 《Journal of Applied Communication Research》2004,32(1):4-27
This study examines mistreatment through the perspectives of employees with different cultural backgrounds and positions in order to understand the ways in which some voices are muted and others are privileged. Mistreatment is interactional, distributive, procedural, or systemic abuse of employees taking place at both interpersonal and institutional levels on the basis of cultural diversity. Narrative analysis of semi-structured interviews with employees of a large research and development organization revealed three types of muted narratives used to respond to mistreatment (muted-but-engaged, angrily disengaged, and resigned) as well as one type of privileged response. The narratives provided evidence of two processes by which voices became muted: repeated silencing over time and silencing through ambiguity of policies. 相似文献
107.
Creating Access to Invisible Special Collections: Using Participatory Management to Reduce a Backlog
The University of Colorado at Boulder Libraries used participatory management to reduce a special collections backlog. Without an increase in budget or staffing, technical and public services departments designed a pilot project to redeploy internal human resources in a collaborative manner. The process of backlog management is discussed. 相似文献
108.
Subjective Social Location: Data From 21 Nations 总被引:1,自引:0,他引:1
109.
110.
Stewart M Brower 《Journal of the Medical Library Association》2004,92(4):412-420
BACKGROUND: The analysis included forty-one academic health sciences library (HSL) Websites as captured in the first two weeks of January 2001. Home pages and persistent navigational tools (PNTs) were analyzed for layout, technology, and links, and other general site metrics were taken. METHODS: Websites were selected based on rank in the National Network of Libraries of Medicine, with regional and resource libraries given preference on the basis that these libraries are recognized as leaders in their regions and would be the most reasonable source of standards for best practice. A three-page evaluation tool was developed based on previous similar studies. All forty-one sites were evaluated in four specific areas: library general information, Website aids and tools, library services, and electronic resources. Metrics taken for electronic resources included orientation of bibliographic databases alphabetically by title or by subject area and with links to specifically named databases. RESULTS: Based on the results, a formula for determining obligatory links was developed, listing items that should appear on all academic HSL Web home pages and PNTs. CONCLUSIONS: These obligatory links demonstrate a series of best practices that may be followed in the design and construction of academic HSL Websites. 相似文献