变式促进深度学习，探究提升思维品质——以二次函数中线段问题为例

在整个初中数学知识体系中,二次函数线段问题是重中之重,也是考察的热点.但在传统教学中,学生针对这一部分知识学习依然停留在浅层阶段中,无法触摸知识的内核本质,学生只能解决简单的问题,一旦遇到较复杂的问题就无从下手.鉴于此,唯有基于变式训练,引导学生在一题多变中,完成知识的深度学习,才能真正提升学生的解题效率.本论文就以此作为研究的视角,结合一定的题目,针对二次函数中线段问题的变式训练进行了详细地探究,旨在提升学生的数学解题能力.     

Momentum filtering scheme of cooling atomic clouds for the Chinese Space Station

To obtain cold atom samples with temperatures lower than 100 pK in the cold atom physics rack experiment of the Chinese Space Station, we propose to use the momentum filtering method for deep cooling of atoms. This paper introduces the experimental results of the momentum filtering method verified by our ground testing system. In the experiment, we designed a specific experimental sequence of standing-wave light pulses to control the temperature, atomic number,and size of the atomic cloud. The r...