我们的祖先,在四千年前就认识到了磁现象,不过那时候把磁石叫做“慈石”,意思是说磁石吸引铁,如慈母恋婴儿一样。磁性指南针是我国古代三大发明之一,是人人皆知的了;磁性材料目前广泛地用于电机、仪表、计算机、广播、电视、通讯以及各种尖端技术中,已经成为我们生产和生活中不可缺少的了;用磁性材料治疗病也有很久的历史,近年来发展尤为迅 Our ancestors recognized the magnetic phenomenon about four thousand years ago, but at that time the magnet was called “charity stone,” meaning that the magnet attracted the iron, like the mother-in-law’s baby. Magnetic compass is one of the three ancient inventions in ancient China, it is well known; magnetic materials are widely used in motors, instruments, computers, radio, television, communications and various cutting-edge technologies, has become our production and life Indispensable; the treatment of disease with magnetic materials also has a long history, especially in recent years the development of rapid