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   6783篇
  免费   105篇
  国内免费   9篇
教育   5195篇
科学研究   352篇
各国文化   67篇
体育   622篇
综合类   12篇
文化理论   98篇
信息传播   551篇
  2023年   42篇
  2022年   94篇
  2021年   130篇
  2020年   190篇
  2019年   309篇
  2018年   407篇
  2017年   412篇
  2016年   337篇
  2015年   227篇
  2014年   248篇
  2013年   1400篇
  2012年   254篇
  2011年   202篇
  2010年   161篇
  2009年   168篇
  2008年   155篇
  2007年   141篇
  2006年   136篇
  2005年   120篇
  2004年   120篇
  2003年   119篇
  2002年   116篇
  2001年   104篇
  2000年   87篇
  1999年   64篇
  1998年   56篇
  1997年   52篇
  1996年   58篇
  1995年   46篇
  1994年   61篇
  1993年   60篇
  1992年   44篇
  1991年   61篇
  1990年   53篇
  1989年   56篇
  1988年   47篇
  1987年   62篇
  1986年   34篇
  1985年   26篇
  1984年   25篇
  1983年   31篇
  1982年   29篇
  1981年   30篇
  1980年   28篇
  1979年   37篇
  1978年   32篇
  1977年   29篇
  1976年   24篇
  1975年   22篇
  1974年   18篇
排序方式: 共有6897条查询结果,搜索用时 890 毫秒
31.
The issue of format duplication in academic library collections is increasingly complicated and perplexing in an environment of static or dwindling resources, soaring user expectations, dynamic access models, and inconsistent and changing publisher and vendor pricing structures. The problem is further complicated for libraries serving a university with multiple campus locations. This paper surveys recent investigative projects and highlights the work of a Duplicate Formats Task Force at Pennsylvania State University charged with determining the extent and nature of format duplication at that institution.  相似文献   
32.
33.
This article proposes the incorporation of learning science into the programming and operation of public libraries. Learning science, a multidisciplinary field spanning cognitive science, psychology, neuroscience, economics, anthropology, and linguistics, has identified proven methods for enhancing learning at any age. The article highlights some of the tools and insights that are most relevant to libraries in their role as centers for informal learning.  相似文献   
34.
Automatic detection of source code plagiarism is an important research field for both the commercial software industry and within the research community. Existing methods of plagiarism detection primarily involve exhaustive pairwise document comparison, which does not scale well for large software collections. To achieve scalability, we approach the problem from an information retrieval (IR) perspective. We retrieve a ranked list of candidate documents in response to a pseudo-query representation constructed from each source code document in the collection. The challenge in source code document retrieval is that the standard bag-of-words (BoW) representation model for such documents is likely to result in many false positives being retrieved, because of the use of identical programming language specific constructs and keywords. To address this problem, we make use of an abstract syntax tree (AST) representation of the source code documents. While the IR approach is efficient, it is essentially unsupervised in nature. To further improve its effectiveness, we apply a supervised classifier (pre-trained with features extracted from sample plagiarized source code pairs) on the top ranked retrieved documents. We report experiments on the SOCO-2014 dataset comprising 12K Java source files with almost 1M lines of code. Our experiments confirm that the AST based approach produces significantly better retrieval effectiveness than a standard BoW representation, i.e., the AST based approach is able to identify a higher number of plagiarized source code documents at top ranks in response to a query source code document. The supervised classifier, trained on features extracted from sample plagiarized source code pairs, is shown to effectively filter and thus further improve the ranked list of retrieved candidate plagiarized documents.  相似文献   
35.
Libraries have been the key to preserving culture and historic legacy for centuries. One such treasure cataloged in The Pennsylvania State University (Penn State) Libraries is a collection of over 33,000 Sanborn? Fire Insurance Maps. Originally kept safe in metal drawers, the library has embarked on a journey to digitize this abundance of information, combine it with other media such as photographs, and make it accessible through a web interface. Inspired by these efforts, we accessed this information and took it to the next level. Using state of the art 3D modeling and immersive technologies, we created a historic 3D model and immersive experiences of Penn State, exemplarily for the 1922 campus. The resulting experiences can be accessed through the web but also through head mounted displays (HMDs) and mobile phones in combination with VR viewers such as the Google Cardboard. Additionally, they can be used anywhere in the world or on the campus itself as a way to enable remote and in situ experiences and learning. Immersive experiences let us connect to the past, the present and the future, and as such offer value to digital cultural heritage efforts.  相似文献   
36.
Against the backdrop of Spain’s Transparency Act, this article discusses the presence or otherwise of a series of document types, proposed as management-related transparency indicators, on 61 (8 national and 53 provincial) historic archive websites. Although examples of good practice were identified, the information provided was found to be scant, in particular as regards lines of action, organisational objectives and yearly reports. The information most commonly provided on the websites included the collection classification chart, service use regulations and citizen charters. The inference drawn was that archives, so intently focused on their role in the application of the Act by the organisations they serve, neglect their own administrative obligations in respect of its provisions. The recommendation is that as government-funded and subsidised public service institutions, historic archives should exercise transparency by furnishing the information stipulated in the Act on their websites.  相似文献   
37.
This study was conducted in an environment of widespread use of social media and mobile applications in the mass media. The general goal of the study was to analyze the use of WhatsApp in cybermedia, specifically in radio. A case study was proposed to examine the use of WhatsApp on the program Las mañanas de RNE, broadcast by Spanish National Radio. It was found that the public was very accepting of the program’s initiative to solicit WhatsApp voice messages, beginning in November 2015. The case study used audio files of a direct broadcast that included specific times for audience participation. The use of WhatsApp was accepted by the audience, in addition to the use of the conventional telephone, as a tool well-suited to listener participation in radio programming. Finally, the study highlights the importance of interactive, participatory spaces in broadcasts through the creation of synergies with new forms of online participation.  相似文献   
38.
Two randomised control experiments examined spelling outcomes in a repeated measures design (pre‐test, post‐tests; 1‐day, 1‐month follow‐up, 5‐month follow‐up), where students learned Spanish irregular words through (1) immediate feedback using self‐correction, (2) visual imagery where children imagine and represent words using movement, and (3) copying words. The two control groups engaged in reading and dictation. We expected that methods with kinesthetic components and segmentation of stimuli would yield better orthographic representations in memory. Results showed that orthographic errors on Spanish irregular words diminish when children receive self‐correction instruction. Imagery and copy instruction also reduce these errors, but less consistently. Five months later, self‐correction group maintained their advantage in spelling compared with students who read or performed dictation. Experiment 2 replicated the spelling instruction effects and showed large effects on children who had hardly received any spelling instruction in Spanish. Results indicate that research‐based practices can significantly improve spelling outcomes in primary children.  相似文献   
39.
40.
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