There are such kinds of mathematics idea and method as sign and graph, function, inversion; discussion and so on in the mathematics teaching in the middle school. 用数学思想方法指导学生的学习,数学会变得更容易理解和掌握,中学数学中常见的思想方法有符号和图形思想、函数思想、转化与化归思想、分类讨论思想等等。
Both the surface mean electrostatic potential and the integrated local charge density show no significant sign of charge inversion. 在这种情况下,表面的平均静电势和积分得到的局域电荷密度分布都没有显示出明显的电荷反转现象。