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   19篇
  免费   0篇
教育   16篇
科学研究   1篇
体育   2篇
  2022年   1篇
  2018年   2篇
  2013年   6篇
  2006年   2篇
  2005年   1篇
  2000年   2篇
  1999年   1篇
  1989年   1篇
  1988年   1篇
  1985年   1篇
  1977年   1篇
排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
2.
3.
实践社团:学习型组织知识管理的新趋势   总被引:1,自引:0,他引:1  
实践社团(Community of Practice,缩写为CoP)由哈佛大学教授Etienne Wenger在1998年正式提出,其他译法还包括知识社群、实务社群、实践社群等。  相似文献   
4.
Using student ratings to assess instructional quality of schools should fulfill three requirements: (1) an appropriate level of inter-rater agreement within schools, (2) systematic variance of student ratings between schools, (3) an adequate reliability level of aggregated student ratings. Using international PISA-data (2000–2012; 81 countries, over 55,300 schools, over 1.3 million 15-year olds) this study investigated how these requirements were met regarding indicators of instructional quality (classroom management, cognitive activation, individual learning support). We computed the interrater agreement index rWG(J), as well as the intraclass correlations ICC(1) and ICC(2). Our results showed that (1) student ratings demonstrated a moderate or strong level of agreement for most indicators of instructional quality and (2) instructional quality assessed by students varied systematically between schools. Yet, (3) reliability of aggregated student ratings was not sufficient in many countries. We discuss these results regarding conventions to evaluate agreement, variability, and reliability of student ratings at the school level.  相似文献   
5.
6.
This study examined the effects of prior exercise on the lactate (Tlac) and ventilatory (Tvent) thresholds. Ten healthy male subjects volunteered to perform one-legged cycling. Muscle glycogen reduction was achieved by cycling at 75-85% of maximal heart rate for 60-75 min, and by a low carbohydrate diet. Pre- and post-exercise tests for measuring the thresholds employed a 3-min continuous protocol in 16 W increments. Muscle biopsies (n = 3) were taken from the vastus lateralis before the 'prior exercise' (PE) ride, the post-PE threshold test, and before testing the non-exercised (NE) leg. An i.v. catheter was used for serial blood lactate concentration determination during rest and the final 30 s of each progressive load. Ventilatory gas analyses were performed every 30 s. Biopsies showed that the PE and diet regimen reduced muscle glycogen in the PE leg (46.7%) and NE leg (36.4%). Venous blood lactate and respiratory exchange ratio (R) were reduced at Tlac and Tvent in both the PE and NE leg. The VO2 at a blood lactate concentration of 4 mmol l-1 was elevated in the PE leg at Tlac (2.89 versus 2.46 1 min-1), but not in the NE leg at Tlac. These results suggest that lactate concentration at Tlac and Tvent is reduced by endurance exercise performed 24 h prior to testing, and that the central circulation plays a major role in this response. Furthermore, since blood lactate is reduced at the thresholds by prior exercise, the use of a lactate level of 4 mmol l-1 as a criterion for Tlac should be interpreted cautiously.  相似文献   
7.
Abstract

This article looks at the development of the Prestel and TTNS systems of videotext and how they have come together to produce the Campus 2000 System which is becoming increasingly important in UK educational systems.

  相似文献   
8.
9.
The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team‘s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC.Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL)and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, including the design criteria, use cases, signaling and payload structure.  相似文献   
10.
Summary A one-semester applied mathematical optimization course has been developed at the University of Wisconsin-Green Bay. The problems for the course were derived from the current research literature in environmental sciences. The use of computer subroutines for problem-solving is a key feature of the course.  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