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低压断路器的短路动作显示
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作者 林思东 《江苏电器》 1998年第2期10-10,共1页
文章扼要地介绍了低压断路器的短路动作显示问题。
关键词 低压断路器 短路保护 动作显示
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体育教学中动作示范的几个要点
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作者 刘明慈 《河南教育(基教版)(上)》 1998年第9期25-25,共1页
示范是体育教学中最主要的一种直观教学方法。它不仅能够清晰地展现动作的全过程,使学生了解所要学习的动作形象、结构和完成的顺序,而且,标准的示范能够将动作的力度、速度和节奏和谐完美地结合起来,产生形象、生动的美感,从而有... 示范是体育教学中最主要的一种直观教学方法。它不仅能够清晰地展现动作的全过程,使学生了解所要学习的动作形象、结构和完成的顺序,而且,标准的示范能够将动作的力度、速度和节奏和谐完美地结合起来,产生形象、生动的美感,从而有效地激发学生学习的兴趣和热情,提高... 展开更多
关键词 体育教学 动作示范 背越式跳高 体育教师 教学效果 技术环节 显示动作 动作概念 教学任务 俯卧式跳高
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长拳与太极拳的阴阳之我见
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作者 秦子来 《体育成人教育学刊》 1997年第3期15-16,共2页
关键词 阴阳 对立因素 套路运动 长拳运动 太极拳比赛 运动过程 运动方法 显示动作 武术套路 一阴一阳之谓道
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Characteristics of Fluid Flow and Heat Transfer in the Shell Side of the Trapezoidal-like Tilted Baffles Heat Exchanger 被引量:4
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作者 GU Xin ZHENG Zhiyang +3 位作者 XIONG Xiaochao WANG Tongtong LUO Yuankun WANG Ke 《Journal of Thermal Science》 SCIE EI CAS CSCD 2018年第6期602-610,共9页
Periodic whole cross-section computation models are established for segmental baffle heat exchanger, shutter baffle heat exchanger, and trapezoid-like tilted baffle heat exchanger. The reliability of models is verifie... Periodic whole cross-section computation models are established for segmental baffle heat exchanger, shutter baffle heat exchanger, and trapezoid-like tilted baffle heat exchanger. The reliability of models is verified by comparing the simulated results to the results obtained from the Bell-Delaware method. Due to the orthogonal assembly of the baffles, the shell side fluid shows the twisty flow of trapezoid-like tilted baffle heat exchanger. The essential mechanism on disturbing flow and heat transfer enhancement is revealed by defining the non-dimensional factor η of the shell side fluid flow direction of heat exchanger and the field synergy principle. The results show that at the same Reynolds number, the shell side fluid convection heat transfer coefficient of trapezoid-like tilted baffle heat exchanger is 12.43%-24.33% and 6.71%-11.51% higher than those of segmental baffle heat exchanger and shutter baffle heat exchanger, respectively. The shell side fluid flow velocity field and the pressure gradient field of trapezoid-like tilted baffle heat exchanger and shutter baffle heat exchanger decreases compared with that of segmental baffle heat exchanger, so the shell side fluid flow resistance and pressure drop is increased; the shell side comprehensive performance of trapezoid-like tilted baffle heat exchanger is 5.85%-9.06% higher than that of segmental baffle heat exchanger, and 15.27%-23.28% higher than that of shutter baffle heat exchanger. In this study, a baffle structure with higher efficiency of the energy utilization for the heat exchanger is provided. 展开更多
关键词 shell-and-tube heat exchanger trapezoid-like tilted baffle twisty flow field synergy principle
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