9.The technical measures and structure,applied principles of blastproof of ventilation shaft at excavating face,specific operational method and prospective effect are described.
10.Aged patients may be hypoxemic during normal spontaneous ventilation postoperatively because of the mechanical changes of the aged lung and chest wall.
11.The results obtained show that airflow reversal of declensional ventilation is catastrophic and the reversal may occur even in higher quantity of ventilation airflow.
13.A displacement ventilation system was provided, it can form the "air layer" at the bottom of room so that resistance dewiness air meet directly the cold floor surface.