Principles of Chemical Engineering _ Volume I _ Revised Edition _ (by Xia Qing _ Chen Changgui _) _ Electronic version or scanned copy of this book and solutions to after-school exercises Tianjin University Press. The first revised edition of Principles of Chemical Engineering, Xia Qing Chen Changgui, Tianjin University Press, is an officially published academic book, and the answers to the exercises after class should be in the corresponding problem set or answer book.

If you need an electronic version or a scanned copy of this book, I suggest you get it through the following channels:

1. Online Bookstore: You can buy e-books or paper books in online bookstores such as JD.COM and Dangdang.

2. Library: If there is an agency of Tianjin University Press nearby, you can try to borrow it there.

3. Scanned copy: You can search scanned copy resources on some scanned copy websites or forums, but you should pay attention to copyright issues.

Please note that if you need a scanned copy of a paper book, I suggest you buy a paper book before scanning it. Because the quality of scanned documents may affect the reading experience because of resolution, clarity and other issues.