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   13676篇
  免费   23篇
  国内免费   4篇
教育   10432篇
科学研究   1398篇
各国文化   26篇
体育   582篇
综合类   13篇
文化理论   425篇
信息传播   827篇
  2023年   8篇
  2022年   25篇
  2021年   56篇
  2020年   68篇
  2019年   112篇
  2018年   2285篇
  2017年   2187篇
  2016年   1654篇
  2015年   179篇
  2014年   204篇
  2013年   431篇
  2012年   296篇
  2011年   757篇
  2010年   894篇
  2009年   471篇
  2008年   684篇
  2007年   1195篇
  2006年   112篇
  2005年   467篇
  2004年   522篇
  2003年   454篇
  2002年   201篇
  2001年   72篇
  2000年   57篇
  1999年   24篇
  1998年   13篇
  1997年   21篇
  1996年   9篇
  1995年   19篇
  1994年   11篇
  1993年   6篇
  1992年   8篇
  1991年   19篇
  1990年   8篇
  1989年   13篇
  1988年   6篇
  1986年   6篇
  1985年   7篇
  1984年   7篇
  1983年   6篇
  1982年   10篇
  1981年   6篇
  1980年   7篇
  1978年   6篇
  1977年   8篇
  1975年   5篇
  1974年   8篇
  1973年   5篇
  1966年   6篇
  1963年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
The purpose of this study was to analyse the raw lifting speed collected during four different resistance training exercises to assess the optimal sampling frequency. Eight physically active participants performed sets of Squat Jumps, Countermovement Jumps, Squats and Bench Presses at a maximal lifting speed. A linear encoder was used to measure the instantaneous speed at a 200 Hz sampling rate. Subsequently, the power spectrum of the signal was computed by evaluating its Discrete Fourier Transform. The sampling frequency needed to reconstruct the signals with an error of less than 0.1% was f99.9 = 11.615 ± 2.680 Hz for the exercise exhibiting the largest bandwidth, with the absolute highest individual value being 17.467 Hz. There was no difference between sets in any of the exercises. Using the closest integer sampling frequency value (25 Hz) yielded a reconstruction of the signal up to 99.975 ± 0.025% of its total in the worst case. In conclusion, a sampling rate of 25 Hz or above is more than adequate to record raw speed data and compute power during resistance training exercises, even under the most extreme circumstances during explosive exercises. Higher sampling frequencies provide no increase in the recording precision and may instead have adverse effects on the overall data quality.  相似文献   
103.
104.
105.
106.
107.
ABSTRACT

We performed a randomized, controlled trial to analyse the effects of resistance training (RT) on cognitive and physical function among older adults. Fifty participants (mean age 67 years, ~60% woman) were randomly assigned to an RT program or a control group. Participants allocated to RT performed three sets of 10-15RM in nine exercises, three times per week, for 12-weeks. Control group did not perform any exercise. Variables included cognitive (global and executive function) and physical function (gait, mobility and strength) outcomes. At completion of the intervention, RT was shown to have significantly mitigated the drop in selective attention and conflict resolution performance (Stroop test: -494.6; 95%CI: -883.1; ?106.1) and promoted a significant improvement in working memory (digit span forward: -0.6; 95%CI: ?1.0; ?0.1 and forward minus backward: -0.9; 95% CI: ?1.6; ?0.2) and verbal fluency (animal naming: +1.4, 95%CI 0.3, 2.5). No significant between-group differences were observed for other cognitive outcomes. Regarding physical function, at completion of the intervention, the RT group demonstrated improved fast-pace gait performance (?0.3; 95% CI: ?0.6; ?0.0) and 1-RM (+21.4 kg; 95%CI: 16.6; 26.2). No significant between-group differences were observed for other mobility-related outcomes. In conclusion, RT improves cognitive and physical function of older adults.  相似文献   
108.
Virtual microscopy (VM) is a widely used teaching method in Medical Education in many developed countries. In Brazil, however, this is not the case for most medical schools, considering Brazilian social inequality and uneven access to technology. Recently, the Covid-19 pandemic has also challenged Universities to seek and make a transition toward more effective methods of full-time online education. Thus, the main goal of this work was to verify student's perception and academic performance, assessed upon VM implementation in a Brazilian Medical School. Ribeirao Preto Medical School students answered a 26-question survey with regards to optical microscopy (OM) and VM. Academic performance was compared between participants that were (year of 2019) or were not (year of 2015) exposed to VM. Taken the results together, subjective impressions such as handling, suitability, learning effectiveness, and pleasure using the tools, have shown a higher score for virtual microscopy (median = 29), when compared to optical microscopy (median = 24) with a P-value < 0.001 by Wilcoxon rank test, upon measurement using an ordinal scale. Regarding academic performance, no statistically significant differences were found between groups (P-value = 0.38, Cohen's d = 0.19). Therefore, VM proved to be adequate to the Brazilian medical education in light of Brazilian social contexts and Covid-19 pandemic.  相似文献   
109.
110.
Marc Torka 《Minerva》2018,56(1):59-83
Funding is an important mechanism for exercising influence over ever more parts of academic systems. In order to do so, funding agencies attempt to export their functional and normative prerequisites for financing to new fields. One essential requirement for fundees is then to construct research processes in the form of a project beforehand, one that is limited in time, scope and content. This article demonstrates how the public funding of doctoral programs expands this model of project research from experienced academics to the socialization process for the new academic generation. This process of “projectification” underlies funding-driven institutional changes in doctoral training. A multi-level comparative study of German policies, funding mechanisms and organizational frameworks for doctoral training demonstrates the emergence of a specific model of predefined PhD projects. The investigation of doctoral training practices reveals that socio-epistemic preconditions regulate whether research fields adopted or rejected this demanding model. This result contradicts widespread claims about a radical change in doctoral training and suggests focusing on the actual practices of field-specific doctoral research.  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