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   1991篇
  免费   54篇
  国内免费   1篇
教育   1607篇
科学研究   47篇
各国文化   21篇
体育   113篇
文化理论   17篇
信息传播   241篇
  2023年   28篇
  2022年   27篇
  2021年   49篇
  2020年   61篇
  2019年   99篇
  2018年   144篇
  2017年   146篇
  2016年   119篇
  2015年   73篇
  2014年   98篇
  2013年   414篇
  2012年   69篇
  2011年   50篇
  2010年   37篇
  2009年   46篇
  2008年   47篇
  2007年   31篇
  2006年   30篇
  2005年   35篇
  2004年   31篇
  2003年   28篇
  2002年   19篇
  2001年   11篇
  2000年   14篇
  1999年   15篇
  1998年   20篇
  1997年   16篇
  1996年   15篇
  1995年   13篇
  1994年   8篇
  1993年   13篇
  1992年   18篇
  1991年   15篇
  1990年   7篇
  1988年   7篇
  1987年   7篇
  1986年   7篇
  1985年   7篇
  1983年   11篇
  1982年   7篇
  1981年   9篇
  1980年   8篇
  1979年   11篇
  1978年   11篇
  1975年   9篇
  1974年   9篇
  1971年   8篇
  1970年   7篇
  1969年   10篇
  1966年   9篇
排序方式: 共有2046条查询结果,搜索用时 218 毫秒
71.
72.
73.

A semi-structured interview was used to enquire into the knowledge of models and modelling held by a total sample of 39 Brazilian science teachers working in 'fundamental' (ages 6-14 years) and 'medium' (ages 15-17 years) schools, student teachers, and university teachers. This paper focuses on their perceptions of the role of models in science teaching. The teachers' ideas are organized in three groups: the status and value of models; the influences that inform the translation of these general ideas into classroom practice; and how they respond to the outcomes of students' modelling activities. The teachers interviewed generally showed an awareness of the value of models in the learning of science but not of their value in learning about science. They were also uncertain of the relationship that could exist in the classroom between various types of models. Modelling, as an activity by students, whilst praised in theory, would not seem to be widely practised. Where practised, the outcomes are by no means always treated with that integrity that learning about science would call for.  相似文献   
74.
75.
76.
Previous studies analysing electromyograms (EMGs) from indwelling electrodes have indicated that fast-twitch motor units are selectively recruited for low-intensity eccentric contractions. The aim of this study was to compare the frequency content of surface EMGs from quadriceps muscles during eccentric and concentric contractions at various contraction intensities. Electromyograms were recorded from the rectus femoris, vastus lateralis and vastus medialis muscles of 10 men during isokinetic (1.05 rad x s(-1)) eccentric and concentric knee extension contractions at 25%, 50%, 75% and 100% of maximal voluntary contraction (MVC) for each contraction mode. Additionally, isometric contractions (70 degrees) were performed at each intensity. The mean frequency and root mean square (RMS) of the surface EMG were computed. Mean frequency was higher for eccentric than concentric contractions at 25% (P < 0.01), 50% (P < 0.01) and 75% (P < 0.05) but not at 100% MVC. It increased with increasing contraction intensity for isometric (P < 0.001) and concentric (P < 0.01) contractions but not for eccentric contractions (P = 0.27). The EMG amplitude (RMS) increased with increasing contraction intensity similarly in each contraction mode (P < 0.0001). Higher mean frequencies for eccentric than concentric contractions at submaximal contraction intensities is consistent with more fast-twitch motor units being active during eccentric contractions.  相似文献   
77.
78.
79.
The purpose of this study was to develop a submaximal, 1.5-mile endurance test for college-aged students using walking, jogging, or running exercise. College students (N = 101: 52 men, 47 women), ages 18-26years, successfully completed the 1.5-mile test twice, and a maximal graded exercise test. Participants were instructed to achieve a "somewhat hard" exercise intensity (rating of perceived exertion = 13) and maintain a steady pace throughout each 1.5-mile test. Multiple linear regression generated the following prediction equation: VO2 max = 65.404 + 7.707 x gender (1 = male; 0 =female) - 0.159 x body mass (kg) - 0.843 x elapsed exercise time (min; walking, jogging orrunning). This equation shows acceptable validity (R = .86, SEE = 3.37 ml x kg(-1) min(-1)) similar to the accuracy of comparable field tests, and reliability (ICC = .93) is also comparable to similar models. The statistical shrinkage is minimal (R(press) = 0.85, SEE(press) = 3.51 ml x kg(-) x min(-1)); hence, it should provide comparable results when applied to other similar samples. A regression model (R =.90, and SEE = 2.87 ml x kg(-1) min(-1)) including exercise heart rate was also developed: VO2 max = 100.162 +/- 7.301 x gender(1 = male; 0 =female) - 0.164 x body mass (kg) - 1.273 x elapsed exercise time -0.156 x exercise heart rate, for those who have access to electronic heart rate monitors. This submaximal 1.5-mile test accurately predicts maximal oxygen uptake (VO2max) without measuring heart rate and is similar to the 1.5-mile run in that it allowsfor mass testing and requires only a flat, measured distance and a stopwatch. Further, it can accommodate a wide range of fitness levels (from walkers to runners).  相似文献   
80.
‘It's important that we remember the past is not just dry facts and statistics but also the detailed lives of real people. SAPPHIRE aims to give a voice to these lives.’ The Scottish Archive of Print and Publishing History Records (SAPPHIRE), an initiative with Napier University as lead and Queen Margaret University College as main collaborative partner, is an oral history project which aims to record the social, economic and cultural heritage of the Scottish printing and publishing industry in the 20th century. Undertaken in partnership with a number of Scottish organizations, its results are providing a better understanding of an important and overlooked part of Scotland's heritage. Outcomes of the project include a permanent oral history archive stored at the Edward Clark Collection at Napier University, and exhibitions and publications on the history of the printing and publishing industry. The development and current activities of SAPPHIRE are described and reviewed.  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