فهرست مقالات Sulfonated rice husk ash دسترسی آزاد مقاله صفحه چکیده متن کامل 1 - Introduction of sulfonated rice husk ash as a highly efficient reusable catalyst for the protection of the hydroxyl group Farhad Shirini Masoumeh Abedini Mahnaz Shamsi-Sani Mohadeseh Seddighi