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   23539篇
  免费   379篇
  国内免费   15篇
教育   16862篇
科学研究   2057篇
各国文化   228篇
体育   1944篇
综合类   13篇
文化理论   175篇
信息传播   2654篇
  2022年   182篇
  2021年   268篇
  2020年   398篇
  2019年   621篇
  2018年   850篇
  2017年   821篇
  2016年   730篇
  2015年   433篇
  2014年   674篇
  2013年   4594篇
  2012年   645篇
  2011年   659篇
  2010年   478篇
  2009年   493篇
  2008年   553篇
  2007年   490篇
  2006年   442篇
  2005年   419篇
  2004年   379篇
  2003年   365篇
  2002年   353篇
  2001年   483篇
  2000年   399篇
  1999年   365篇
  1998年   209篇
  1997年   220篇
  1996年   250篇
  1995年   239篇
  1994年   189篇
  1993年   211篇
  1992年   325篇
  1991年   303篇
  1990年   305篇
  1989年   301篇
  1988年   261篇
  1987年   314篇
  1986年   268篇
  1985年   309篇
  1984年   253篇
  1983年   215篇
  1982年   197篇
  1981年   171篇
  1980年   158篇
  1979年   258篇
  1978年   187篇
  1977年   170篇
  1976年   155篇
  1975年   141篇
  1974年   150篇
  1971年   144篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
ABSTRACT

Lighting a cultural heritage artifact requires balancing visual perception with preventive conservation, by providing the best lighting (in terms of spectral distribution and quantity) to enable the viewer to appreciate details and color, while limiting photo-induced degradation. The paper outlines the methodology applied by a multi-disciplinary team while lighting the Shroud of Turin at its last public exhibition in 2015. The methodology considered the special requirements of the Shroud, including exposure to ultraviolet light, while providing appropriate display conditions that would meet audience expectations. The desired appearance (readability of the body image and color) was defined with the help of Shroud researchers and confirmed by subjective tests, while appropriate light levels for preservation were set in agreement with standard requirements and using knowledge of the degradation of linen in visible and UV light. The installation provided a controlled environment and a managed visitor route to the Shroud, assuring excellent perception of both details and color, with the lowest illuminance level about 15?lx.  相似文献   
72.
This research analyzed a dataset of academic libraries' posts on Facebook. It applied a text and data analytics approach to a dataset collected from the Facebook posts of academic libraries at the top 100 English-speaking universities, as listed by the 2014 Shanghai World University Rankings. The dataset is from a two-year posting history of 18,333 unique posts, 113,621 likes, and 3401 comments. Less than a quarter of the libraries had more than 2000 post-related likes, and only seven received more than 100 comments on their postings. Content analysis identified the most prevalent single word (unigrams), bigrams (two-word sequences), and trigrams (three-word sequences) in high and low engagement content. Semantic analysis identified the semantic categories for posts with high and low engagement. The findings can assist academic libraries in their social media strategies for engagement, marketing, and visibility.  相似文献   
73.
74.
75.
History and case study are two diachronic research strategies commonly used to study political discourse as it relates to public libraries. Though suitable for some studies, these strategies are inexhaustive. A new, blended research strategy is therefore needed to accomplish what history and case study alone cannot. This hybrid strategy, historical case study, must analyze cases from the distant past to the present, using eclectic data sources, in order to produce both idiographic and nomothetic knowledge. To develop historical case study, the universal components of diachronic analysis are first identified. A general research design for historical case study is then introduced. Finally, historical case study is tested in an actual research project. Findings from this project reveal that historical case study is a successful diachronic research strategy. Historical case study is a new and valuable research design suitable for addressing questions related to change, continuity, development, and evolution.  相似文献   
76.
77.
Digital inclusion is a strategy pursued to foster social inclusion of those who have been sidelined from the mainstream of information society due to lack of access to digital technologies and the skills to use them. Libraries have been working to close the gap by providing access to computers, the Internet, digital content, and digital literacy programs. However, research reveals a new type of divide where digitally competent people could be digitally excluded. This shows the need for a better conceptualization of access and literacy. This paper commits to exploring the concept of access to digital content from the perspective of people with print disability. It involved in-depth interviews with ten participants with print disability where the International Classification of Functioning, Disability, and Health was used as a framework for data analysis. The overall analysis shows that digital inclusion would be more meaningful if it involved providing content in alternative formats and empowering users to make informed choices. Issues such as flexibility and adaptability in content presentation and design of content discovery tools are among those discussed.  相似文献   
78.
This article explores the existence of a “citizen-centered journalism” that sees citizens as crucial participants in the construction of news and as co-creators of their own worlds. Through qualitative case studies of three news organizations, the article examines the motivation for using a citizen-centered approach, the news routines that are required to do so, the categories of content produced, and the perceived impact of this approach. The results suggest these news organizations are working in partnership with communities and striving to give a voice to historically marginalized communities. The journalists, however, see citizen participation as complementary to professional journalistic routines that favor verifiable information, rather than assigning inherent value to it for its own sake.  相似文献   
79.
Electrolyte anions are critical for achieving high-voltage stable potassium-metal batteries (PMBs). However, the common anions cannot simultaneously prevent the formation of ‘dead K’ and the corrosion of Al current collector, resulting in poor cycling stability. Here, we demonstrate cyclic anion of hexafluoropropane-1,3-disulfonimide-based electrolytes that can mitigate the ‘dead K’ and remarkably enhance the high-voltage stability of PMBs. Particularly, even using low salt concentration (0.8 M) and additive-free carbonate-based electrolytes, the PMBs with a high-voltage polyanion cathode (4.4 V) also exhibit excellent cycling stability of 200 cycles with a good capacity retention of 83%. This noticeable electrochemical performance is due to the highly efficient passivation ability of the cyclic anions on both anode and cathode surfaces. This cyclic-anion-based electrolyte design strategy is also suitable for lithium and sodium-metal battery technologies.  相似文献   
80.
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