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   111篇
  免费   3篇
教育   55篇
科学研究   46篇
体育   5篇
综合类   1篇
信息传播   7篇
  2022年   1篇
  2020年   3篇
  2019年   4篇
  2018年   15篇
  2017年   8篇
  2016年   7篇
  2015年   7篇
  2014年   10篇
  2013年   8篇
  2012年   6篇
  2011年   5篇
  2010年   4篇
  2009年   2篇
  2008年   3篇
  2007年   4篇
  2005年   6篇
  2003年   2篇
  2002年   1篇
  1996年   1篇
  1990年   2篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1973年   1篇
  1963年   2篇
  1961年   1篇
排序方式: 共有114条查询结果,搜索用时 46 毫秒
51.
52.
International Review of Education - While European education systems fundamentally rest on a rather monolithic world-view, some of them are explicitly oriented towards Christianity and others are...  相似文献   
53.
54.
In this study, we examined the effect of two metacognitive scaffolds on the accuracy of confidence judgments made while diagnosing dermatopathology slides in SlideTutor. Thirty-one (N = 31) first- to fourth-year pathology and dermatology residents were randomly assigned to one of the two scaffolding conditions. The cases used in this study were selected from the domain of nodular and diffuse dermatitides. Both groups worked with a version of SlideTutor that provided immediate feedback on their actions for 2 h before proceeding to solve cases in either the Considering Alternatives or Playback condition. No immediate feedback was provided on actions performed by participants in the scaffolding mode. Measurements included learning gains (pre-test and post-test), as well as metacognitive performance, including Goodman–Kruskal Gamma correlation, bias, and discrimination. Results showed that participants in both conditions improved significantly in terms of their diagnostic scores from pre-test to post-test. More importantly, participants in the Considering Alternatives condition outperformed those in the Playback condition in the accuracy of their confidence judgments and the discrimination of the correctness of their assertions while solving cases. The results suggested that presenting participants with their diagnostic decision paths and highlighting correct and incorrect paths helps them to become more metacognitively accurate in their confidence judgments.  相似文献   
55.
摘要:目的:探讨在不同半蹲屈膝角度情况下接受不同重力加速度(g)的全身振动训练(Whole-body vibration,WBV),下肢股内侧肌(Vastus medium,VM)与股二头肌(Bicepes femoris,BF)激活表现以及两者共同收缩变化。方法:46名健康男性大学生,以表面肌电仪监测惯用腿VM与BF肌电反应。先以3种角度(90、60、45°)半蹲姿势进行无振动刺激(Non-Vibration,NV)测试,再以相同3种屈膝角度接受WBV,振动刺激为随机采用0.98、2.52、3.72、5.61 等4种g值。统计学显著性水平为P<0.05,以配对样本T检验比较NV与WBV的肌电信号。因变量为NV与WBV的标准化肌电比例(%MVC),自变量为g值与屈膝角度。以双因素方差分析比较不同g 值、角度的肌电反应差异以及共同收缩比例,主效应检验g值与屈膝角度对肌电信号的影响,交互作用检验不同g值振动刺激下屈膝角度差异对肌电信号的影响。结果:BF%MVC在屈膝60 °搭配0.98~3.72g 与45°搭配0.98~5.61g 的振动刺激情况下,显著高于NV,而VM在屈膝45°搭配0.98和2.52 g 时有显著提升肌肉激活的效果。结论:BF与VM的激活程度受半蹲屈膝角度影响较大,而屈膝45°搭配0.98、2.52等2种g 值对于BF与VM有较佳激活效果。  相似文献   
56.
Determination of amyloid β (Aβ) isoforms and in particular the proportion of the Aβ 1-42 isoform in cerebrospinal fluid (CSF) of patients suspected of Alzheimer's disease might help in early diagnosis and treatment of that illness. Due to the low concentration of Aβ peptides in biological fluids, a preconcentration step prior to the detection step is often necessary. This study utilized on-chip immunoprecipitation, known as micro-immunoprecipitation (μIP). The technique uses an immunosorbent (IS) consisting of magnetic beads coated with specific anti-Aβ antibodies organized into an affinity microcolumn by a magnetic field. Our goal was to thoroughly describe the critical steps in developing the IS, such as selecting the proper beads and anti-Aβ antibodies, as well as optimizing the immobilization technique and μIP protocol. The latter includes selecting optimal elution conditions. Furthermore, we demonstrate the efficiency of anti-Aβ IS for μIP and specific capture of 5 Aβ peptides under optimized conditions using various subsequent analytical methods, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), capillary electrophoresis, microchip electrophoresis, and immunoblotting. Synthetic Aβ peptides samples prepared in buffer and spiked in human CSF were analyzed. Finally, on-chip immunoprecipitation of Aβ peptides in human CSF sample was performed.  相似文献   
57.
Abstract

As access to the Internet has become increasingly essential for social and economic participation, public domain Internet measurements have become indispensable for users to validate quality of service their network operator delivers and for policymakers to identify and address gaps in broadband infrastructure. This article evaluates public domain Internet performance measurements available for assessing the state of connectivity and developing universal access service quality standards in Canada. The analysis suggests that different approaches to Internet measurement represent complementary windows into a complex and fast evolving reality of broadband connectivity. Despite their potential shortcomings, large-scale crowdsourced open data network testing platforms have a central role to play in enabling broadband infrastructure policy coordination across different levels of government, empowerment of consumers, and achievement of universal service objectives for quality of service users experience when accessing the open Internet.  相似文献   
58.
This paper deals with observer-based control design for a class of switched discrete-time linear systems with parameter uncertainties. The main contribution of the paper is to propose a convenient way based on Finsler’s lemma to enhance the synthesis conditions, expressed in terms of Linear Matrix Inequalities (LMIs). Indeed, this judicious use of Finsler’s lemma provides additional decision variables, which render the LMIs less conservative and more general than all those existing in the literature for the same class of systems. Two numerical examples followed by a Monte Carlo evaluation are proposed to show the superiority of the proposed design technique.  相似文献   
59.
60.
Conditions are given for underdamped or overdamped linear dynamical systems in terms of loop matrix parameters, (√(C)R√(C)g,g)2 ? 4(√(C)L√(C)g,g) for all [boxV]g[boxV] = 1, g ∈ H. These criteria are looked upon as natural generalizations of the elementary one-loop RLC series scalar criteria (R/2L)2 ? 1/LC, when written in the more suggestive form: (√(C)R√(C))2 ? 4√(C)L√(C). A simplified test for determining dynamical systems with all complex natural modes or all real modes are presented with additional comments.  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