Abstract: An electroluminescent device includes a first electrode and a second electrode facing each other; an emission layer disposed between the first electrode and the second electrode and including a plurality of quantum dots and a first hole transporting material having a substituted or unsubstituted C4 to C20 alkyl group attached to a backbone structure; a hole transport layer disposed between the emission layer and the first electrode and including a second hole transporting material; and an electron transport layer disposed between the emission layer and the second electrode.

Abstract: A double boiler for domestic use includes a heating vessel for receiving water and a filtering device containing food, the vessel having a lid on the top; a main case having a reception hollow and a heater at one side so that the heating vessel is mounted and heated; a steam condenser incorporated in the top end of the main case so that steam produced from the heating vessel is collected; steam cooling device for circulating cooling water along the inner and outer circumferential surfaces of the steam condenser so that the steam collected in the steam condenser becomes cooled; and a condensed water collecting device for receiving the heating vessel to the hollow of the main case and at the same time connecting the heating vessel and steam condenser so that the condensed water condensed in the steam condenser is gathered into the heating vessel.