Abstract: An ultraviolet absorber formulation and a method of preparing the same. The ultraviolet absorber formulation comprises a zinc oxide powder and a transparent coating on surfaces of the zinc oxide powder, thus forming a core-shell structure. The ultraviolet absorber is prepared by wet chemical surface modification. A zinc oxide powder is dispersed by media or non-media milling to provide a slurry of zinc oxide. The zinc oxide slurry is subjected to a coating process to deposit a transparent coating, thus giving the ultraviolet absorber.

Abstract: A door structure primarily consists of a door leaf, a door frame, a retaining piece, and a retaining mechanism. The door leaf has a wedged side corresponding to a slant side surface of the door frame and a groove formed on the opposite side surface. The retaining piece, disposed in the groove of the door leaf, has a supporting portion on one side and a retaining portion on the other side. The front end of the retaining portion extends to form a mating portion. The retaining mechanism is composed of a latching device and an actuating device. The latching device is provided with a transverse lock rod, an upper lock rod, and a lower lock rod. These lock rods can be urged to move by an actuating rod of the actuating device. When closing the door leaf, the actuating rod of the actuating device is depressed into the door leaf and the transverse lock rod, the upper lock rod, and the lower lock rod of the door leaf and extend into the holes of the door frame.