13.Carbon tetrabromide was prepared from acetone and sodium hypobromite by adding tetrabutylammonium bromide.The yield and purity were very satisfactory.
16.Objective: According to different manifestation and formation mechanism of eye haustra , various therapy methods were chosen to achieve satisfactory effects.
19.The inner parts of the drying tower and alkali subsider were reformed with the surf ace-treated regular plastic packing and the results are satisfactory.
20.Humic acid is a kind of organic matter with high molecular quantity and satisfactory biological activity, and there are abundant humic acid in airslake-coal.