In order to balance a chemical equation it is essential that it represent a reaction in true manner . 为了配平一个化学方程式，必须如实表达反应情况。
2.
With the deepening of their cognition to multimedia , people are more strict with multimedia producing tool . maintop alkald multimedia compiling system appears and develops meeting users needs constantly 在制作理科的课件时公式和化学方程式的录入是必不可少的，但是能支持直接输入这类公式的软件不多。
3.
The structure evolution and reaction mechanism of silicon - iron composite powders treated at the temperature ranging from 700 c to 1200 c respectively were carefully investigated through xrd , sem , epma , dsc . it was found that the chemical formula , fe + si - fe ( si ) + fe3si ( si ) , controls the reaction process , and the reaction mechanism of powder homogenization was clarified 通过利用xrd ， sem ， epma ， dsc等多种测试手段，详细研究了铁硅复合粉末带材在700 1200的热处理温度条件下的反应状况及结构变化，明确了反应过程中的化学方程式： fe + si fe ( si ) + fe _ 3si ( si ) ，并解释了各个热处理温度范围内，铁硅粉末均一化的反应机理。
