Always open a carbon dioxide cylinder valve slowly.

Place 100 mL of pyridine in a 250-mL graduated cylinder , and, keeping the pyridine cold in an ice bath, pass in dry sulfur dioxide until the volume reaches 200 mL.

In 1979, Beijing institute of electrical carbon dioxide laser is developed, and the kilowatt in early 1980s respectively applied in cylinder and stamp printing equipments of laser treatment.