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高校图书馆构建新的信息资源和网络环境 总被引：2，自引：0，他引：2
本文主要探讨高校图书馆在网络环境中，构建新的信息资源和网络环境的方法和措施，以及新的服务功能和服务内容对图书馆传统馆藏服务的影响。 相似文献
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Changes in muscle activity with increasing running speed 总被引：3，自引：2，他引：1
Electromyographic (EMG) activity of the leg muscles and the ground reaction forces were recorded in 17 elite male middle-distance runners, who performed isometric maximal voluntary contractions (MVC) as well as running at different speeds. Electromyograms were recorded from the gluteus maximus, vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior. The results indicated that the averaged EMG (aEMG) activities of all the muscles studied increased (P < 0.05) with increasing running speed, especially in the pre-contact and braking phases. At higher speeds, the aEMG activities of the gastrocnemius, vastus lateralis, biceps femoris and gluteus maximus exceeded 100% MVC in these same phases. These results suggest that maximal voluntary contractions cannot be used as an indicator of the full activation potential of human skeletal muscle. Furthermore, the present results suggest that increased pre-contact EMG potentiates the functional role of stretch reflexes, which subsequently increases tendomuscular stiffness and enhances force production in the braking and/or propulsive phases in running. Furthermore, a more powerful force production in the optimal direction for increasing running speed effectively requires increased EMG activity of the two-joint muscles (biceps femoris, rectus femoris and gastrocnemius) during the entire running cycle. 相似文献
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To develop a track version of the maximal anaerobic running test, 10 sprint runners and 12 distance runners performed the test on a treadmill and on a track. The treadmill test consisted of incremental 20-s runs with a 100-s recovery between the runs. On the track, 20-s runs were replaced by 150-m runs. To determine the blood lactate versus running velocity curve, fingertip blood samples were taken for analysis of blood lactate concentration at rest and after each run. For both the treadmill and track protocols, maximal running velocity (v max), the velocities associated with blood lactate concentrations of 10 mmol x l-1 (v10 mM) and 5 mmol x l(-1) (v5 mM), and the peak blood lactate concentration were determined. The results of both protocols were compared with the seasonal best 400-m runs for the sprint runners and seasonal best 1000-m time-trials for the distance runners. Maximal running velocity was significantly higher on the track (7.57 +/- 0.79 m x s(-1)) than on the treadmill (7.13 +/- 0.75 m x s(-1)), and sprint runners had significantly higher vmax, v10 mM, and peak blood lactate concentration than distance runners (P < 0.05). The Pearson product--moment correlation coefficients between the variables for the track and treadmill protocols were 0.96 (v max), 0.82 (v10 mM), 0.70 (v5 mM), and 0.78 (peak blood lactate concentration) (P < 0.05). In sprint runners, the velocity of the seasonal best 400-m run correlated positively with vmax in the treadmill (r = 0.90, P < 0.001) and track protocols (r = 0.92, P < 0.001). In distance runners, a positive correlation was observed between the velocity of the 1000-m time-trial and vmax in the treadmill (r = 0.70, P < 0.01) and track protocols (r = 0.63, P < 0.05). It is apparent that the results from the track protocol are related to, and in agreement with, the results of the treadmill protocol. In conclusion, the track version of the maximal anaerobic running test is a valid means of measuring different determinants of sprint running performance. 相似文献
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遥远的格林兰岛有处静谧土地上生活着一群平凡的人。摄影师Jo(e|¨)l拍下了其独特色彩,气候和建筑系统的关联形成了一派未见的风景。行走其间,不乏温暖的人情,也有扑面而来的凛冽孤独,这是远离城市的非常状态。居民对如此景色习以为常,而外界的人们却因路长莫及。于是纯洁的色彩进入镜头,沉淀成照片,化作人们在心里静静向往的一方净土。 相似文献
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本文主要结合广西玉林至铁山港高速公路施工路段,翼C合同段的水泥混凝土路面主要设置在互通收费广场、服务区和二级路连接线路面,针对合同段内的水泥混凝土路面施工技术做了分析和阐述。 相似文献
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中学语文新课标的实施,为广大语文教师提供了广阔的空间。在这个过程中,有部分教师对“课程”“课程标准”及《语文课程标准》等概念认识不够,理解不深。笔者在文中拟将对上述概念作诠释,以便各位同仁在教学过程中参考。一、什么是“课程”“课程”一词有广义和狭义之分。广义的“课程”是指为实现各级各类学校的培养目标而规定的教育内容及其目的、范围和进程的总和。“课”,是指课业,即教育内容;“程”,是指程度、程序和进程。狭义的“课程”概念,是指一门学科及其进程。目前“课程”的定义大概有几种:(1)课程即教学科目。(2)课程即有计划… 相似文献
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一位高一的学生在国内时被其老师称为没有“学习头脑”，而到了美国以后，则被其老师称为“学习天才”。同一个学生，中国老师和美国老师的评价截然相反。由此，这位学生的家长说出了这样一席话：“处在学习过程中的学生就像一杯没有倒满的水，在中国老师这里通常看到一半是空的，而在美国老师那里却总是看到一半是满的。”前否定，后肯定。我们暂且称这种现象为“半杯水”现象。为什么会产生这种现象呢? 相似文献