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   30874篇
  免费   482篇
  国内免费   22篇
教育   22258篇
科学研究   2708篇
各国文化   361篇
体育   2373篇
综合类   17篇
文化理论   277篇
信息传播   3384篇
  2022年   212篇
  2021年   307篇
  2020年   460篇
  2019年   742篇
  2018年   1017篇
  2017年   1021篇
  2016年   907篇
  2015年   582篇
  2014年   853篇
  2013年   6285篇
  2012年   789篇
  2011年   814篇
  2010年   632篇
  2009年   631篇
  2008年   716篇
  2007年   668篇
  2006年   596篇
  2005年   579篇
  2004年   527篇
  2003年   495篇
  2002年   479篇
  2001年   594篇
  2000年   511篇
  1999年   487篇
  1998年   309篇
  1997年   319篇
  1996年   351篇
  1995年   368篇
  1994年   297篇
  1993年   297篇
  1992年   423篇
  1991年   393篇
  1990年   390篇
  1989年   395篇
  1988年   344篇
  1987年   391篇
  1986年   343篇
  1985年   399篇
  1984年   344篇
  1983年   299篇
  1982年   291篇
  1981年   239篇
  1980年   202篇
  1979年   323篇
  1978年   249篇
  1977年   243篇
  1976年   216篇
  1975年   194篇
  1974年   202篇
  1973年   183篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
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   
152.
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   
153.
The purpose of this ecological study was to examine the impact of a library credit course on graduation rates and GPA using pre-existing records. Over 20?years of aggregate institutional data were analyzed to evaluate the course's impact on first-time-full-time, white, and black students. Results were mixed: students who took the course were less likely to graduate than their peers who did not take the course but enjoyed slightly higher GPAs at graduation. It was discovered that students taking the course are not representative of the overall student body and struggle academically. Implications for revisions to the library credit course are discussed.  相似文献   
154.
155.
156.
This paper identifies individuals’ accumulated history with Information and Communication Technologies (ICTs) as a replacement for the contested and outdated term ‘digital divide.’ We propose that an individual’s ability to benefit from their technological history consists of four factors: awareness, knowledge, access, and technological capacity of the user’s social collective. Together, these factors make up the individual’s level or amount of Technological Capital. The development of this construct was based on empirical research conducted in Soweto, South Africa, and through an analysis of the literature on assessing individuals’ accumulated histories. The concept of technological capital has the potential for application in fields in which ICTs are used for communication, capacity building, and identifying barriers to adoption of new technologies. The use of the concept may have implications for policy decisions, resource allocation, and future research into differences among individuals’ and communities’ ability to benefit from the introduction of new technologies.  相似文献   
157.
158.
In 2008 Meier and Conkling first tested Google Scholar's coverage of the engineering literature against citations gathered from the Compendex database. Since that time, other studies have used the same methodology and found improvement in Google Scholar's coverage. This study uses engineering dissertations from Proquest Dissertations & Theses to create a data set of citations for the comparison of fee-based databases, Compendex and Scopus, against Google Scholar. From 1950 to 2017 Google Scholar outperformed both Compendex and Scopus in discoverability of citations in nine engineering subjects. These results have implications for collection management and information literacy program planning for librarians.  相似文献   
159.
ABSTRACT

The career path and significant professional accomplishments of librarian Valerie Bross (1954–2016) are described in this article. The awards and recognition she received are recounted and the influence of outside activities on her career is assessed. An attempt is made to capture what she was like as a professional, as well as what her unique characteristics were. A bibliography of her writings and a photograph are included.  相似文献   
160.
ABSTRACT

The Harwood Institute arrived in Youngstown, Ohio, in 1999; and today, over 18 years later, its teachings have made a profound effect upon the city. The Youngstown Public Library, through the leadership of Carlton Sears and Heidi Daniel, has wholeheartedly embraced the methods and ideology of the Harwood Institute, helping to reinvigorate and power a city working its way back to prosperity.  相似文献   
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