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朱建江 《中国教育技术装备》2004,(9):34-35
介绍了运用Powerpoint 2002制作楞次定律演示课件的过程和技巧。 相似文献
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Charles A. J. Macaulay Pro Stergiou Darren Stefanyshyn Luciano Tomaghelli 《Journal of sports sciences》2017,35(23):2350-2356
Lacrosse requires the coordinated performance of many complex skills. One of these skills is shooting on the opponents’ net using one of three techniques: overhand, sidearm or underhand. The purpose of this study was to (i) determine which technique generated the highest ball velocity and greatest shot accuracy and (ii) identify kinematic and kinetic variables that contribute to a high velocity and high accuracy shot. Twelve elite male lacrosse players participated in this study. Kinematic data were sampled at 250 Hz, while two-dimensional force plates collected ground reaction force data (1000 Hz). Statistical analysis showed significantly greater ball velocity for the sidearm technique than overhand (P < 0.001) and underhand (P < 0.001) techniques. No statistical difference was found for shot accuracy (P > 0.05). Kinematic and kinetic variables were not significantly correlated to shot accuracy or velocity across all shot types; however, when analysed independently, the lead foot horizontal impulse showed a negative correlation with underhand ball velocity (P = 0.042). This study identifies the technique with the highest ball velocity, defines kinematic and kinetic predictors related to ball velocity and provides information to coaches and athletes concerned with improving lacrosse shot performance. 相似文献
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Alan Paisey Head of Administrative Studies Keith Alan‐Smith Pro‐Rector 《School Leadership & Management》2013,33(4):333-340
Today's school leaders are searching for a way to give value to and effectively manage a school's intangible assets to create a more holistic picture of student success. Schools establish partnerships with community organizations towards this end and to ultimately impact student learning. Utilizing the framework of principals as knowledge managers, this paper describes how school principals involved in a university partnership developed a tool to manage and intentionally utilize the intangible assets of the school–university partnership to increase student learning. Included are examples of how the tool was applied and suggestions for adapting the tool to any school partnership. 相似文献
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Ricardo Peterson Silveira Pro Stergiou Felipe P. Carpes Flávio A. de S. Castro Larry Katz Darren J. Stefanyshyn 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(2):177-186
The aim of this study was to determine the precision and accuracy of the vertical and anterior–posterior force components of the portable PASCO PS-2142 force plate. Impulse, peak force, and time to peak force were assessed and compared to a gold standard force plate in three different tasks: vertical jump, forward jump, and sprint start. Two healthy male participants performed ten trials for each task, resulting in 60 trials. Data analyses revealed good precision and accuracy for the vertical component of the portable force plate, with relative bias and root mean square (RMS) error values nearly the same in all tasks for the impulse, time to peak force, and peak force parameters. Precision and accuracy of the anterior–posterior component were lower for the impulse and time to peak force, with relative bias and RMS error values nearly the same between tasks. Despite the lower precision and accuracy of the anterior–posterior component of the portable force plate, these errors were systematic, reflecting a good repeatability of the measure. In addition, all variables presented good agreement between the portable and gold standard platforms. Our results provide a good perspective for using the aforementioned portable force plate in sports and clinical biomechanics. 相似文献
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Ricardo Peterson Silveira Pro Stergiou Pedro Figueiredo Flávio de S. Castro Larry Katz Darren J. Stefanyshyn 《European Journal of Sport Science》2018,18(10):1317-1326
The aim of this study was to determine the biomechanical parameters that explain ventral start performance in swimming. For this purpose, 13 elite swimmers performed different variants of the ventral start technique. Two-dimensional video analyses of the aerial and underwater phases were used to assess 16 kinematic parameters from the starting signal to 5?m, and an instrumented starting block was used to assess kinetic data. A Lasso regression was used to reduce the number of parameters, providing the main determinants to starting performance, revealing different combinations of key determinants, depending on the variant (r²?≥?0.90), with flight distance being the most relevant to all variants (r?≤??0.80; p?r?=??0.79; p?r?≤?0.61; p?r²?=?0.66) or block time and flight distance (r²?=?0.83). These data provide relevant contributions to the further understanding of the biomechanics of swimming starts as well as insights for performance analysis and targeted interventions to improve athlete performance. 相似文献
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