Various embodiments relating to a packaging box for packaging an electronic device are presented, and according to one embodiment, the packaging box comprises: a packaging box body; a receiving part included in the packaging box body and receiving the electronic device; and a support structure received in or removed from the receiving part, at least a portion of the supporting structure able to be slantedly folded to or unfolded, wherein the support structure in a folded state is received, together with the electronic device, in the receiving part to support the electronic device to be able to amplify a sound from a speaker included in the electronic device and, in a state removed from the receiving part or in a state received in the receiving part, the supporting structure cradles the electronic device, and additional various other embodiments are possible.

Various embodiments relating to a packaging box for packaging an electronic device are presented, and according to one embodiment, the packaging box comprises: a packaging box body; a receiving part included in the packaging box body and receiving the electronic device; and a support structure received in or removed from the receiving part, at least a portion of the supporting structure able to be slantedly folded to or unfolded, wherein the support structure in a folded state is received, together with the electronic device, in the receiving part to support the electronic device to be able to amplify a sound from a speaker included in the electronic device and, in a state removed from the receiving part or in a state received in the receiving part, the supporting structure cradles the electronic device, and additional various other embodiments are possible.

A composite material and structure. The structure has a folded sheet having a rigid inner layer sandwiched between flexible outer layers. The sheet has an undulated shape with alternating summit and valley portions. Intermediate portions each extend between adjacent summit and valley portions. At least one score line extends through at least one of the flexible outer layers. The sheet is folded about the at least one score line. A method of forming a structure from a sheet having an undulated shape.

A composite material and structure. The structure has a folded sheet having a rigid inner layer sandwiched between flexible outer layers. The sheet has an undulated shape with alternating summit and valley portions. Intermediate portions each extend between adjacent summit and valley portions. At least one score line extends through at least one of the flexible outer layers. The sheet is folded about the at least one score line. A method of forming a structure from a sheet having an undulated shape

Disclosed is a sleeve-type mortise-and-tenon joint structure unit, comprising: an externally wrapping pipe-type frame (1) and several internally supported pipe-type frames (2) disposed in the externally wrapping pipe-type frame. The externally wrapping pipe-type frame is provided with several openings (3). After some or all of the internally supported pipe-type frames are pulled out of an end part of the externally wrapping pipe-type frame, a vacant part (4) is formed in the externally wrapping pipe-type frame, and the openings and the vacant part form a mortise structure. Further disclosed are two applications of the sleeve-type mortise-and-tenon joint structure unit. The above-mentioned sleeve-type mortise-and-tenon joint structure unit has the advantages of requiring no nail or binder, a stable structure, rapid and convenient assembly and disassembly, durability, lightweightness, reusability, and environmental friendliness.