Abstract: A semiconductor memory device, and a method of manufacturing the semiconductor memory device, includes a first source layer, a second source layer on the first source layer, a stack on the second source layer, a channel structure passing through the stack and the second source layer, and a common source line passing through the stack and the second source layer. The second source layer includes an air gap and a conductive layer surrounding the air gap.

Abstract: Provided are an external heating-type aerosol generating device and a cigarette used therein. Because heat energy is easily transferred to the cigarette, a sufficient amount of smoke may be provided to a user in initial puffs so that the user may have a satisfactory smoking experience.

Abstract: Provided is an adhesive composition including lysine, alpha ketoglutaric acid, and water, wherein the lysine and the alpha ketoglutaric acid are present in the form of an aqueous salt solution and do not form precipitates in the aqueous solution.

Abstract: A multiple variable valve lift apparatus may include a camshaft, a plurality of cams slidably fitted on the camshaft and each having a cam base with a guide groove and a cam lobe, a solenoid valve including an actuating rod capable of being selectively inserted into the guide groove of a cam in the plurality of cams, and a valve opening/closing unit capable of selectively coming in contact with any cam in the plurality of cams.

Abstract: A multiple variable valve lift apparatus may include a camshaft, a plurality of cams slidably fitted on the camshaft and each having a cam base with a guide groove and a cam lobe, a solenoid valve including an actuating rod capable of being selectively inserted into the guide groove of a cam in the plurality of cams, and a valve opening/closing unit capable of selectively coming in contact with any cam in the plurality of cams.

Abstract: A variable valve lift apparatus may include a camshaft, a low lift cam which may be connected to the camshaft and rotates, a high lift cam which may be rotatably mounted to the camshaft and may be selectively connected to the camshaft to rotate with the camshaft, a high lift cam connecting portion which selectively connects the high lift cam to the camshaft, and a tappet including a low lift cam contact portion contacting the low lift cam and a high lift cam contact portion selectively activating the high lift cam.

Abstract: A hydraulic pressure valve apparatus includes a housing of which a first chamber and a second chamber are formed therein, wherein a diameter of the second chamber is bigger than that of the first chamber, a first piston disposed within the first chamber, an elastic portion disposed within the first chamber for elastically supporting the first piston and a second piston disposed within the second chamber and connected to a valve.

Abstract: A variable compression ratio apparatus for an engine receiving combustion force of an air-fuel mixture from a piston and rotating a crankshaft, and for changing compression ratio of the air-fuel mixture.

Abstract: A hydraulic pressure valve apparatus includes a housing of which a first chamber and a second chamber are formed therein, wherein a diameter of the second chamber is bigger than that of the first chamber, a first piston disposed within the first chamber, an elastic portion disposed within the first chamber for elastically supporting the first piston and a second piston disposed within the second chamber and connected to a valve.

Abstract: A variable compression ratio apparatus for an engine receiving combustion force of an air-fuel mixture from a piston and rotating a crankshaft, and for changing compression ratio of the air-fuel mixture.

Abstract: A variable valve lift apparatus including an inner tappet, an outer tappet surrounding and slidably contacting the inner tappet, and a latching pin slidably inserted into the inner tappet so as to implement a high lift and a low lift by selectively joining the inner tappet and the outer tappet may include a stopper partially inserted into the outer tappet and spaced apart from the latching pin in a movement direction of the latching pin so as to limit movement of the latching pin, and forming a latching pin joining groove in the outer tappet to selectively receive the latching pin, wherein the stopper partially projects to the outside of the outer tappet and is slidably engaged to a cylinder head groove formed to a cylinder head bore to prevent the variable valve lift apparatus from being rotated.

Abstract: A variable valve lift apparatus may include a camshaft, a low lift cam which may be connected to the camshaft and rotates, a high lift cam which may be rotatably mounted to the camshaft and may be selectively connected to the camshaft to rotate with the camshaft, a high lift cam connecting portion which selectively connects the high lift cam to the camshaft, and a tappet including a low lift cam contact portion contacting the low lift cam and a high lift cam contact portion selectively activating the high lift cam.