全文获取类型
收费全文 | 11796篇 |
免费 | 10篇 |
专业分类
教育 | 9119篇 |
科学研究 | 1219篇 |
各国文化 | 9篇 |
体育 | 362篇 |
综合类 | 1篇 |
文化理论 | 382篇 |
信息传播 | 714篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 14篇 |
2018年 | 2177篇 |
2017年 | 2087篇 |
2016年 | 1589篇 |
2015年 | 117篇 |
2014年 | 132篇 |
2013年 | 142篇 |
2012年 | 223篇 |
2011年 | 696篇 |
2010年 | 843篇 |
2009年 | 444篇 |
2008年 | 652篇 |
2007年 | 1152篇 |
2006年 | 75篇 |
2005年 | 400篇 |
2004年 | 451篇 |
2003年 | 364篇 |
2002年 | 131篇 |
2001年 | 11篇 |
2000年 | 28篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 15篇 |
1996年 | 1篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 8篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Experimentation and Innovation in U.S. Publishing Today: Findings from the Book Industry Study Group
Michael Healy 《Publishing Research Quarterly》2008,24(4):233-239
In February 2008 the Book Industry Study Group (BISG) conducted a survey of U.S. publishers to determine the extent of technology-driven
innovation and experimentation. The survey findings were published alongside a set of 10 case studies in May 2008 as “From
experimentation to innovation in the digital age—case studies from the North American Book Industry 2008”. This article, written
by Michael Healy, Executive Director of the BISG, summarizes the circumstances that led to the survey and shares the key findings. 相似文献
972.
Panagiotis Symeonidis Alexandros Nanopoulos Apostolos N. Papadopoulos Yannis Manolopoulos 《Information Retrieval》2008,11(1):51-75
Collaborative Filtering (CF) Systems have been studied extensively for more than a decade to confront the “information overload”
problem. Nearest-neighbor CF is based either on similarities between users or between items, to form a neighborhood of users
or items, respectively. Recent research has tried to combine the two aforementioned approaches to improve effectiveness. Traditional
clustering approaches (k-means or hierarchical clustering) has been also used to speed up the recommendation process. In this paper, we use biclustering
to disclose this duality between users and items, by grouping them in both dimensions simultaneously. We propose a novel nearest-biclusters
algorithm, which uses a new similarity measure that achieves partial matching of users’ preferences. We apply nearest-biclusters
in combination with two different types of biclustering algorithms—Bimax and xMotif—for constant and coherent biclustering,
respectively. Extensive performance evaluation results in three real-life data sets are provided, which show that the proposed
method improves substantially the performance of the CF process.
相似文献
Yannis ManolopoulosEmail: |
973.
This article addresses the trajectory of Archival Science in Brazil, its extracurricular characteristics and its particular relationship with Information Science within academics, its institutional associations, and some considerations regarding current training for archivists in Brazil. The methodological procedures used included analyzing documents from the National Archive Fonds of Brazil, reviewing archive literature, and interviewing people involved in consolidating Archival Science. This study concludes that Archival Science research is taking place in graduate programs throughout public Brazilian universities and points out that people working with archives now have more advanced training, such as undergraduate degrees in Archival Science or other. This study also focuses on archives as information units, while presenting and reflecting on the demands of training archivists who are faced with the challenges of the working world and the era of information and knowledge—challenges that go beyond merely technical procedures and encompass dynamic planning and orientation activities. 相似文献
974.
A compressed full-text self-index for a text T, of size u, is a data structure used to search for patterns P, of size m, in T, that requires reduced space, i.e. space that depends on the empirical entropy (H
k
or H
0) of T, and is, furthermore, able to reproduce any substring of T. In this paper we present a new compressed self-index able to locate the occurrences of P in O((m + occ)log u) time, where occ is the number of occurrences. The fundamental improvement over previous LZ78 based indexes is the reduction of the search
time dependency on m from O(m
2) to O(m). To achieve this result we point out the main obstacle to linear time algorithms based on LZ78 data compression and expose
and explore the nature of a recurrent structure in LZ-indexes, the suffix tree. We show that our method is very competitive in practice by comparing it against other state of the art compressed
indexes.
相似文献
Arlindo L. OliveiraEmail: |
975.
Objective: The research analyzes usage of a major biomedical library''s pre-1993 print journal collection.Methodology: In July 2003, in preparation for a renovation and expansion project, the Biomedical Library at the University of California, San Diego, moved all of its pre-1993 journal volumes off-site, with the exception of twenty-two heavily used titles. Patrons wishing to consult one of these stored volumes could request that it be delivered to the library for their use. In the spring of 2006, an analysis was made of these requests.Results: By July of 2006, 79,827 journal volumes published in 1992 or earlier had been requested from storage. The number of requests received declined with age of publication. The usage distribution exhibited a “long tail”: 50% of the 79,827 requests were for journal volumes published before 1986. The availability of electronic access dramatically reduced the chance that corresponding print journal volumes would be requested.Conclusions: The older biomedical print journal literature appears to be of continued value to the biomedical research community. When electronic access was provided to the older literature, demand for older print volumes declined dramatically.
Highlights
- Analysis of requests for stored biomedical journal volumes published prior to 1993 indicates that older biomedical journal literature receives substantial use: during this 3-year study, there were nearly 80,000 requests for journal volumes published in 1992 or earlier, with half the requests for volumes published from 1986–1992 and 40% of the request for volumes published from 1970–1985. These results indicate that retaining older print volumes, or providing easy access to the older literature through electronic journals or other means, will likely be required to meet user information needs.
- Use of older journal volumes varies by title and by user population, and a small number of journal titles were responsible for most of the use.
- Requests for older print biomedical journal titles dropped significantly when electronic access became available.
Implications
- Biomedical libraries should carefully consider implications of eliminating on-site access to older journal literature for users and budgets.
- Removing access to older journal literature may result in higher demand for interlibrary loan and document delivery services.
- Biomedical libraries can safely substitute reliable electronic access to older literature to meet ongoing needs for this information, thereby creating space for other purposes.
976.
Play is an important activity in young children’s lives. It is how children explore their world and build knowledge. Although free play, which is play that is totally child directed, contributes to children’s learning, self-regulation and motivation, adults’ participation in children’s play is critical in their development, especially their language development. Guided by children, adults can help scaffold children’s language, and especially their learning. We suggest that adults scaffold children’s language during play by using research based strategies such as asking questions that invite extended responses and new inquiry, provide meaningful feedback and effectively use wait time, which provides children with the opportunity to respond to adults’ comments and questions. The goal is to provide adults with strategies to scaffold children’s language development during play while allowing children to direct their own play activities. 相似文献
977.
Jeff Seger 《Communication methods and measures》2017,11(1):31-48
Construct validity was investigated of a measure of remote past television viewing in which adults reported their childhood viewing of specific television series. Good recall of past viewing was predicted due to two robust memory capabilities, specifically, high accuracy at estimating frequency of exposure to stimuli, and durable long-term memories for repeatedly-encountered material. Validity was tested by examining relationships between self-reported childhood TV viewing and current aggression. Results indicated that recalled childhood viewing of programs containing violent content was positively related to adult aggressive behavior directly, and aggressive cognitions indirectly, independently of adult exposure to violent TV programs, exposure to nonviolent TV programs, parental disciplinary style, and sex. A valid self-report measure of remote past TV viewing behavior can enable researchers to examine, in a relatively quick and inexpensive manner, long-term relationships between early viewing of any television content and any later psychological outcomes of interest. 相似文献
978.
Gary E. Bingham Margaret F. Quinn Kyla McRoy Xiao Zhang Hope K. Gerde 《Early Childhood Education Journal》2018,46(6):601-611
Despite the importance of early writing development to children’s school success, research documents that early childhood teachers spend little time actively supporting children’s writing development in preschool classrooms. This article provides a framework for integrating writing experiences across the early childhood curriculum. Practical examples are given regarding how writing opportunities can be incorporated into existing activities and play settings. The metaphor of backgrounding and foregrounding writing experiences is used to illustrate ways that teachers can set writing rich environments and activities in a manner that makes it easier for teachers to bring these experiences into everyday learning opportunities. Attention is given to how teachers can bring writing to the foreground of the curriculum by drawing attention to writing materials, making natural connections with children’s interest and play, and scaffolding children’s early writing attempts and experiences. 相似文献
979.
980.