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   1222篇
  免费   9篇
  国内免费   2篇
教育   820篇
科学研究   147篇
各国文化   22篇
体育   83篇
综合类   1篇
文化理论   33篇
信息传播   127篇
  2019年   21篇
  2018年   32篇
  2017年   26篇
  2016年   17篇
  2015年   16篇
  2014年   15篇
  2013年   337篇
  2012年   15篇
  2011年   31篇
  2010年   16篇
  2009年   24篇
  2008年   27篇
  2007年   25篇
  2006年   15篇
  2005年   15篇
  2004年   23篇
  2003年   13篇
  2002年   15篇
  2001年   16篇
  2000年   12篇
  1999年   15篇
  1998年   11篇
  1997年   11篇
  1996年   14篇
  1995年   17篇
  1994年   17篇
  1993年   21篇
  1992年   18篇
  1991年   13篇
  1990年   14篇
  1989年   8篇
  1988年   10篇
  1987年   16篇
  1986年   18篇
  1985年   12篇
  1984年   12篇
  1983年   10篇
  1982年   12篇
  1981年   11篇
  1980年   14篇
  1979年   16篇
  1978年   14篇
  1977年   17篇
  1976年   16篇
  1975年   10篇
  1974年   15篇
  1973年   11篇
  1970年   7篇
  1966年   9篇
  1920年   8篇
排序方式: 共有1233条查询结果,搜索用时 15 毫秒
51.
The aim of the present study was to examine the relationship between the performance heart rate during an ultra-endurance triathlon and the heart rate corresponding to several demarcation points measured during laboratory-based progressive cycle ergometry and treadmill running. Less than one month before an ultra-endurance triathlon, 21 well-trained ultra-endurance triathletes (mean +/- s: age 35 +/- 6 years, height 1.77 +/- 0.05 m, mass 74.0 +/- 6.9 kg, = 4.75 +/- 0.42 l x min(-1)) performed progressive exercise tests of cycle ergometry and treadmill running for the determination of peak oxygen uptake (VO2peak), heart rate corresponding to the first and second ventilatory thresholds, as well as the heart rate deflection point. Portable telemetry units recorded heart rate at 60 s increments throughout the ultra-endurance triathlon. Heart rate during the cycle and run phases of the ultra-endurance triathlon (148 +/- 9 and 143 +/- 13 beats x min(-1) respectively) were significantly (P < 0.05) less than the second ventilatory thresholds (160 +/- 13 and 165 +/- 14 beats x min(-1) respectively) and heart rate deflection points (170 +/- 13 and 179 +/- 9 beats x min(-1) respectively). However, mean heart rate during the cycle and run phases of the ultra-endurance triathlon were significantly related to (r = 0.76 and 0.66; P < 0.01), and not significantly different from, the first ventilatory thresholds (146 +/- 12 and 148 +/- 15 beats x min(-1) respectively). Furthermore, the difference between heart rate during the cycle phase of the ultra-endurance triathlon and heart rate at the first ventilatory threshold was related to marathon run time (r = 0.61; P < 0.01) and overall ultra-endurance triathlon time (r = 0.45; P < 0.05). The results suggest that triathletes perform the cycle and run phases of the ultra-endurance triathlon at an exercise intensity near their first ventilatory threshold.  相似文献   
52.
53.
54.
Royalties, evolving patent rights, and the value of innovation   总被引:1,自引:0,他引:1  
The value of an innovation to the innovator can change over time, especially in response to changes in the legal protection (such as patent rights) afforded the innovator. A proven-valid-and-infringed patent is a more valuable economic commodity than is an untested patent. The increase in value can be estimated using the success rate of patent lawsuits. Using a database of the outcomes of U.S. patent litigation, we find that plaintiffs win patent litigation some 45% of the time at the trial court level. This has implications both for patent damages awards and for the incentives to innovate.  相似文献   
55.
56.
Workplaces are settings where power, knowledge and self are brought together in a complex social environment which includes various forms of struggle related to identity, agency, socio-cultural norms, political structures and functional practices. The purpose of this article is to uncover how formal and informal work-related learning processes influence the identity transformation of workers with low literacy and essential skills. Drawing on two recent Canadian data bases which serve as cases in this study, the position taken by the authors is that the organisational context can both facilitate and impede worker subjectivity. Various conditions, approaches to learning and training pathways are examined as they contribute to social cognitive and transformative learning theories.  相似文献   
57.
58.
59.
60.
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