As with all chemical process used in the preparation of cotton, the relationship between temperature, length of treatment and concentration of chemical is important.
在准备棉花的所有化学加工过程中，温度，时处理的时间长度和化学品的浓度之间的关系非常重要。
2
Surface preparation of metal before chemical process. Removal of a layer of the base metal.
在化学处理之前的表面准备，移除一层金属基材。
3
The preparation methods of metal nanocatalysts include chemical methods and physical methods.