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博文

目前显示的是标签为“Movement”的博文

Children’s Physical Activity and Associated Variables during Preschool Physical Education

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53978#.VN2uoSzQrzE Author(s)    Bik C. Chow 1 , Thomas L. McKenzie 2 , Lobo Louie 1   Affiliation(s) 1 Department of Physical Education, Hong Kong Baptist University, Kowloon, Hong Kong . 2 School of Exercise and Nutritional Sciences, San Diego State University, San Diego, USA . ABSTRACT Physical activity (PA) is important for children’s growth and development and for their current and future health. Schools, especially during physical education (PE), are important locations for children to accrue PA. The purpose of this study was to assess the PA levels of preschool children during structured PE lessons and to evaluate the impact of selected characteristics (e.g., lesson context, length, and location; teacher behavior; class size; activity area density). Trained observers used SOFIT (System for Observing Fitness Instruction Time) to assess 90...

Exact Equations for the Light Doppler Effect

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=50607#.VEdBPlfHRK0 Author(s)    Joseph J. Smulsky Affiliation(s) Institute of the Earth’s Cryosphere, Siberian Branch of Russian Academy of Sciences, Tyumen, Russia . ABSTRACT The influence of light source on the receiver as electromagnetic interaction is considered. The mechanical influence of the moving charged body on a motionless one is defined in the experimental laws of electrodynamics. These laws determine the changes of parameters of the light source that moves relatively the receiver. The laws of change of light frequency and its direction of the moving source are derived from the laws of electromagnetism. At small vel...