Abstract: A jewelry item includes an inner ring base, an inner ring arranged on the inner ring base, and a decorative body. A slot is provided on an outer surface of the inner ring base. The inner ring defines a through hole at a position corresponding to the slot. The decorative body includes a mounting column. The mounting column passes through the through hole and is limited in the slot. The decorative body is limited to the inner ring base by a triple limit locking structure, which completely prevents the decorative body and inner ring base from detaching. The limit locking structure is very simple and ingenious. The jewelry item is able to be assembled and disassembled by hands without using tools. Compared with the prior art, the jewelry item is more convenient for a user to assemble, which improves assembly time and efficiency.

Abstract: A three-dimensional (3D) memory device includes a memory stack including conductive layers and dielectric layers interleaving the conductive layers, and a channel structure extending through the memory stack along a vertical direction. The channel structure has a plurality of protruding portions protruding along a lateral direction and facing the conductive layers, respectively, and a plurality of normal portions facing the dielectric layers, respectively, without protruding along the lateral direction. The channel structure includes a plurality of blocking structures in the protruding portions, respectively, and a plurality of storage structures in the protruding portions and over the plurality of blocking structures, respectively. A vertical dimension of each of the blocking structures is nominally the same as a vertical dimension of a respective one of the storage structures over the blocking structure.

Abstract: A first opening extending vertically through a dielectric stack is formed above a substrate. The dielectric stack includes vertically interleaved dielectric layers and sacrificial layers. Parts of the sacrificial layers facing the opening are removed to form a plurality of first recesses. A plurality of stop structures are formed along sidewalls of the plurality of first recesses. A plurality of storage structures are formed over the plurality of stop structures in the plurality of first recesses. The plurality of sacrificial layers are removed to expose the plurality of stop structures from a plurality of second recesses opposing the plurality of first recesses. The plurality of stop structures are removed to expose the plurality of storage structures. A plurality of blocking structures are formed over the plurality of storage structures in the plurality of second recesses.