In the afternoon of June 16, 2023, Mr. Linxiang Lyu successfully passed his PhD oral comprehensive exam. The title of his exam report is “Generation, Degradation, and Recycling of Polypropylene Face Mask Waste Towards Environmentally Sustainable Management”. His profound knowledge and excellent presentation helped him win a good evaluation from the external examiner, Dr. Yaser Khojasteh-Salkuyeh, and other examining committee members (Drs. Joonhee Lee, Zhi Chen, Monisha Bagchi, and Chunjiang An).