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   1915篇
  免费   19篇
  国内免费   11篇
教育   1167篇
科学研究   143篇
各国文化   10篇
体育   444篇
综合类   1篇
文化理论   32篇
信息传播   148篇
  2023年   14篇
  2022年   32篇
  2021年   47篇
  2020年   47篇
  2019年   78篇
  2018年   121篇
  2017年   107篇
  2016年   117篇
  2015年   49篇
  2014年   70篇
  2013年   235篇
  2012年   98篇
  2011年   75篇
  2010年   80篇
  2009年   63篇
  2008年   66篇
  2007年   59篇
  2006年   72篇
  2005年   60篇
  2004年   47篇
  2003年   33篇
  2002年   42篇
  2001年   33篇
  2000年   27篇
  1999年   25篇
  1998年   24篇
  1997年   18篇
  1996年   11篇
  1995年   9篇
  1994年   8篇
  1993年   9篇
  1992年   13篇
  1991年   8篇
  1990年   15篇
  1989年   7篇
  1988年   7篇
  1987年   5篇
  1986年   8篇
  1985年   5篇
  1984年   12篇
  1983年   5篇
  1982年   4篇
  1981年   5篇
  1980年   5篇
  1979年   9篇
  1978年   5篇
  1977年   4篇
  1975年   11篇
  1974年   6篇
  1968年   3篇
排序方式: 共有1945条查询结果,搜索用时 15 毫秒
41.
42.
43.
Background: University physics students were engaged in open-ended thermodynamics laboratory activities with a focus on understanding a chosen phenomenon or the principle of laboratory apparatus, such as thermal radiation and a heat pump. Students had access to handheld infrared (IR) cameras for their investigations.

Purpose: The purpose of the research was to explore students’ interactions with reformed thermodynamics laboratory activities. It was guided by the research question: How do university physics students make use of IR cameras in open-ended investigation of thermal radiation as a phenomenon?

Sample: The study was conducted with a class of first-year university physics students in Sweden. The interaction with the activities of four of the students was selected for analysis. The four students are males.

Design and methods: We used a qualitative, interpretive approach to the study of students’ interaction. The primary means of data collection was video recording of students’ work with the laboratory activities and their subsequent presentations. The analysis focused on how IR cameras helped students notice phenomena relating to thermal radiation, with comparison to previous research on students’ conceptions of thermal radiation.

Results: When using the IR camera, students attended to the reflection of thermal radiation on shiny surfaces, such as polished metals, windows or a whiteboard and emissive properties of surfaces of different types. In this way, they went beyond using the technology as a temperature probe. Students were able to discuss merits and shortcomings of IR cameras in comparison with digital thermometers.

Conclusions: With the help of IR cameras, university physics students attend to thermal phenomena that would otherwise easily go unnoticed.  相似文献   
44.
45.
46.
47.
48.
During the last decades, the education system has been marked by distinct processes of internationalisation. In the field of higher education, there are numerous and varied schools with different international profiles. This paper focuses on processes of internationalisation in the German sector of higher education. We contrast two higher secondary schools with international profiles: one international school in a West German metropolitan region with a long tradition and a younger internationally-profiled school located in the periphery of an East German urban centre. This institutional analysis presents school cultural similarities and differences with regard to different claims and concepts of internationality. This analysis is complemented by a reconstruction of three patterns of biographical meaning examining the internationality of pupils and their respective habitual fit to these internationally-profiled schools. We draw on qualitative data, consisting mainly of interviews with head teachers and pupils of these two schools. We argue that these differing regional forms of internationalisation indicate a stratification and hierarchisation in the field of higher education in Germany.  相似文献   
49.
This article was motivated by the inquiry of the National Heritage Committee of the British House of Commons into the price of compact discs in 1993. Its general thrust is to foster the dialogue between sociological approaches to the study of innovation and microeconomic theory. To do this, it presents a comprehensive case study of technological innovation in the market for recorded music in Britain. The material is analysed with the aid of the ‘sociotechnical constituencies’ approach recently proposed in this journal by Alfonso Molina, followed by a game theoretical analysis of competitive alignment between the dominant constituents. Using this interdisciplinary approach, the article argues that technological innovation may induce price rigidities by allowing the establishment of focal points for tacit collusion. The innovation of compact discs enabled the major record companies to redefine the overall price level to their advantage, after the industry had undergone a period of profit-squeezing price-competition. This has the important policy implication that radical product innovation may call for regulative changes in the techno-institutional structure of the market.  相似文献   
50.
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