Quantity of water solubilization by rust inhibitors was calculated based on the phase digram.

在相图测定的基,算出防锈剂对水的增溶度。

It is a difficult thing for our student to draw a block digram according to a principle digram,the difficulties are analysed and some good methods are also given in this article.

以一道为例，对绘制框图时的几个难点进深入的分析，给出克服困难的方法.