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   9784篇
  免费   239篇
  国内免费   299篇
教育   6084篇
科学研究   1428篇
各国文化   47篇
体育   820篇
综合类   449篇
文化理论   11篇
信息传播   1483篇
  2024年   6篇
  2023年   53篇
  2022年   129篇
  2021年   233篇
  2020年   349篇
  2019年   291篇
  2018年   275篇
  2017年   246篇
  2016年   193篇
  2015年   265篇
  2014年   587篇
  2013年   971篇
  2012年   683篇
  2011年   745篇
  2010年   594篇
  2009年   695篇
  2008年   707篇
  2007年   698篇
  2006年   606篇
  2005年   437篇
  2004年   345篇
  2003年   328篇
  2002年   247篇
  2001年   181篇
  2000年   117篇
  1999年   67篇
  1998年   59篇
  1997年   42篇
  1996年   28篇
  1995年   15篇
  1994年   18篇
  1993年   11篇
  1992年   14篇
  1991年   2篇
  1990年   5篇
  1989年   3篇
  1987年   2篇
  1986年   4篇
  1985年   14篇
  1984年   6篇
  1983年   10篇
  1982年   12篇
  1981年   5篇
  1979年   3篇
  1978年   6篇
  1977年   5篇
  1976年   9篇
  1957年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
This study explores science communication on Twitter by investigating a sample of tweets referring to academic papers in five different scientific fields. The specifications of science communicators on Twitter, the characteristics of those who initiate actions (by tweeting), the extent and quality of reactions (retweeting), individual and group interactions, and the distribution of tweets across types of engagement in the process of science communication (i.e., dissemination, consultation, and evaluation) were explored. A broad array of actors is involved in the communication of science on Twitter, with individual citizens and individual researchers playing an important role. In principle, this is promising for creating direct interaction, which can be difficult through more traditional mass media. The vast majority of communication activities regarding academic papers is undigested dissemination with almost no sign of debate, contestation, or collective reflection. Another general finding of this study is that bot accounts play a major role in the science communication landscape on Twitter.  相似文献   
82.
Citation averages, and Impact Factors (IFs) in particular, are sensitive to sample size. Here, we apply the Central Limit Theorem to IFs to understand their scale-dependent behavior. For a journal of n randomly selected papers from a population of all papers, we expect from the Theorem that its IF fluctuates around the population average μ, and spans a range of values proportional to σ/n, where σ2 is the variance of the population's citation distribution. The 1/n dependence has profound implications for IF rankings: The larger a journal, the narrower the range around μ where its IF lies. IF rankings therefore allocate an unfair advantage to smaller journals in the high IF ranks, and to larger journals in the low IF ranks. As a result, we expect a scale-dependent stratification of journals in IF rankings, whereby small journals occupy the top, middle, and bottom ranks; mid-sized journals occupy the middle ranks; and very large journals have IFs that asymptotically approach μ. We obtain qualitative and quantitative confirmation of these predictions by analyzing (i) the complete set of 166,498 IF & journal-size data pairs in the 1997–2016 Journal Citation Reports of Clarivate Analytics, (ii) the top-cited portion of 276,000 physics papers published in 2014–2015, and (iii) the citation distributions of an arbitrarily sampled list of physics journals. We conclude that the Central Limit Theorem is a good predictor of the IF range of actual journals, while sustained deviations from its predictions are a mark of true, non-random, citation impact. IF rankings are thus misleading unless one compares like-sized journals or adjusts for these effects. We propose the Φ index, a rescaled IF that accounts for size effects, and which can be readily generalized to account also for different citation practices across research fields. Our methodology applies to other citation averages that are used to compare research fields, university departments or countries in various types of rankings.  相似文献   
83.
Dimensions is a partly free scholarly database launched by Digital Science in January 2018. Dimensions includes journal articles and citation counts, making it a potential new source of impact data. This article explores the value of Dimensions from an impact assessment perspective with an examination of Food Science research 2008–2018 and a random sample of 10,000 Scopus articles from 2012. The results include high correlations between citation counts from Scopus and Dimensions (0.96 by narrow field in 2012) as well as similar average counts. Almost all Scopus articles with DOIs were found in Dimensions (97% in 2012). Thus, the scholarly database component of Dimensions seems to be a plausible alternative to Scopus and the Web of Science for general citation analyses and for citation data in support of some types of research evaluations.  相似文献   
84.
澳大利亚国家图书馆展览政策研究   总被引:1,自引:0,他引:1  
李剑 《图书情报工作》2019,63(13):137-144
[目的/意义]国内图书馆对展览政策的研究较少,而国外图书馆在相关领域有比较成熟的做法。研究国外图书馆展览政策有助于促进国内图书馆展览工作的开展。[方法/过程]通过对澳大利亚国家图书馆展览政策与展品租借政策文本的梳理与研究,探索其有益做法对我国图书馆的启示。[结果/结论]我国图书馆应从4方面完善展览工作:①重视展览工作的组织建设;②重视对展览原则的研究;③结合国家文物保护政策制定展品借出政策;④结合我国实际制定展品借入政策。  相似文献   
85.
针对文献学课程作为选修课常常受到文献检索等课程的挤压,作为必修课又受到教学对象主、客观两方面因素的制约的情况,提出文献学对于文史哲等专业的治学研究有指导作用,对于学生知识体系的建构和完善有着非同一般的意义,应该成为文科专业的基础课。改进文献学的教学现状,教师必须注意文献学观念的转变,注意与国学教育相融合,提升自己的学术含量,提高自己的文化品格,实现教学策略的调整。  相似文献   
86.
叶瑜 《科教文汇》2011,(4):123-123,132
中国传统符号的内容很多,怎么在现在的设计中做到古为今用,需要对中国传统符号的精髓彻底消化和贯通。  相似文献   
87.
The promotion of students’ achievement and competence in the so-called STEM disciplines is one cornerstone of current educational research and practice. In particular, as early as elementary school, the fostering of an adequate understanding of science is a normative goal of science education. It facilitates students’ science learning and enables them to understand the nature and development of scientific knowledge. Based on the relevance of the promotion of young children’s understanding of science, a corresponding science intervention was recently developed and successfully evaluated in a first study under highly controlled conditions. The goal of the present study was to investigate the effectiveness of this intervention when implemented in practice. One hundred seventeen third- and fourth-grade students and 10 trained course instructors participated in this study. We applied a randomized block design with waitlist control groups and repeated measures. The results revealed that children assigned to the intervention compared with children assigned to the waitlist control group showed better inquiry-related methodological competencies (a better understanding of the scientific inquiry cycle and experimentation strategies) and a higher need for cognition. The findings point to the successful implementation of the intervention and are compared with the results of the first study.  相似文献   
88.
89.
ABSTRACT

The Australian National Maritime Museum (ANMM) in their Darling Harbour warehouse store just over one thousand Ilma. The Ilma are performance symbols of Bardi law and custom, which tell stories of the lands and seas of the Dampier Peninsula, King Sound and surrounding islands of Western Australia. Ilma performances are public and meant for all to see. The ANMM in 2007 resourced detailed documentation of the collection. In 2018 the collection still does not appear on the online catalogue and remains unavailable for public view. While recent efforts have been put into the collection there are important questions to be raised about the responsibility of museums to collections that have contested meanings and serve multiple purposes.  相似文献   
90.
I examine the effects of a longer school year in Indonesia on grade repetition, educational attainment, employability, and earnings. I exploit an arbitrary rule that assigned students to a longer school year in Indonesia in 1978–1979, which fits a fuzzy regression discontinuity design. I find the longer school year decreases the probability of grade repetition and increases educational attainment; it also increases the probability of working in formal sectors and wages later in life. These results suggest the length of school years in Indonesia is not too long.  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