PtSnSr/HZSM-5 catalysts with different amounts of strontium were prepared by sequential impregnation method,and characterized by BET analysis,TEM,NH3-TPD,H2-TPR
In recent years, the telecommuni-cations have used the concept of NPS (Net Promoter Score) for customer relationship management, but there is neither definite t
Hydrogenation modification is one of the most important ways to produce high-quality petroleum resin.The colorless C9 petroleum resin (C9PR) was obtained by two