Please select the most similar patent number from A, B, C and D. Which number is?
A magnetically sealed display case, comprising a transparent display case (1), a display stand (2), a vacuum pump (3), a pneumatic check valve (4), a magnetic base (5), and a controller (6); the magnetic socket (5) is used to seal and connect the transparent display case (1) and the top panel (7) of the display stand; when a visitor observes an antiquity, he or she can use the rotation switch (30) and the stop switch (31) of the controller (6) to control the rotation and stop of the turntable (25) inside the transparent display case; the visitor can enjoy the rotating antiquity, and can also enjoy from any angle the antiquity when it is stationary, satisfying the requirements of a visitor when enjoying an antiquity; the antiquity is also sealed inside the hermetically sealed chamber (8) of the transparent display case (1), and the hermetically sealed chamber (8) is provided with an inert gas to protect the antiquity inside the chamber.
A: A swaying boat comprising a water tub (1), a boat body (2), a magnetic fluid lifting/lowering apparatus (3), and a controller (4). The magnetic fluid lifting/lowering apparatus (3) is arranged within the water tub (1). The boat body (2) is arranged on the magnetic fluid lifting/lowering apparatus (3). The magnetic fluid lifting/lowering apparatus (3) comprises sealed cylinders (5), pistons (6), piston rods (7), and electromagnetic coils (8). The pistons (6) are arranged within cavities of the sealed cylinders (5). The piston rods (7) are connected to the pistons (6). The piston rods (7) are connected to the boat body (2). The electromagnetic coils (8) are arranged on the outer peripheries of the sealed cylinders (5). The sealed cylinders (5) are provided in the cavities thereof with a magnetic fluid. When in use, people are seated within the swaying boat, the controller is utilized to simulate a state of a boat thrashing in water, while playing and training are carried out on the swaying boat.
B: A chemiluminescent device comprises a luminous body (1) with a cavity enclosed by a transparent or semitransparent film casing. A part of the luminous body (1) is sheathed in one or more waterproof bags (5), and the opening of each waterproof bag (5) is provided with a separating and sealing device (2). The part of the luminous body (1) in the waterproof bag (5) is separated from the part of the luminous body (1) out of the waterproof bag (5) by the separating and sealing device (2) from the exterior of the waterproof bag (5), two or more sealed drug storage cavities (3) are formed, and each waterproof bag (5), meanwhile, is also sealed as a waterproof protective cavity (8) by the separating and sealing device (2). The corresponding drug storage cavities (3) are sealed in the waterproof protective cavities (8) respectively, and radiant agents (9) and oxidizing agents (10) are respectively contained in the different drug storage cavities (3). Another chemiluminescent device is provided, wherein radiant agents (9) and/or oxidizing agents (10) are respectively sealed in breakable drug storage bags (4) with one or more layers, and the exterior of the breakable drug storage bags (4) are provided with an aluminum foil wrap layer (19) composed of one or more layers of aluminum foil. Furthermore, a chemiluminescent device with an image device is provided, wherein the image device (16) is arranged in the luminous body (1); a sleeving sandwiching film chemiluminescent device is provided, with a shell (27) comprising at least one sandwiched cavity (22), and a film chemiluminescent component (23) is arranged in the sandwiched cavity (22).
C: A handicraft showcasing apparatus, comprising a transparent cover (1), a connecting mesa (2), a fixing mesa (3), a first limiting mesa (4), a rotating mesa (9), and a mounting box (10). The fixing mesa (3) and the rotating mesa (9) are disk-shaped structures. The rotating mesa (9) is rotatably provided on the fixing mesa (3). The rotating mesa (9) and the fixing mesa (3) are coaxially provided. The rotating mesa (9) is arranged inside the transparent cover (1). The fixing mesa (3) is provided on the mounting box (10). A groove (301) is provided on top of the fixing mesa (3). The groove (301) is an arced groove. A driving structure used for driving the rotating mesa (9) to rotate is provided within the mounting box (10). The transparent cover (1) is a cylindrical structure. A step is provided on the connecting mesa (2). The first limiting mesa (4) is provided on the fixing mesa (3). A first limiting space used for embedding the step is provided between the bottom of the first limiting mesa (4) and the groove bottom of the groove (301). The showcasing apparatus allows the transparent cover to be mounted conveniently, thus implementing protection for a handicraft, and also allows the handicraft to rotate with the rotating mesa (9), thus favoring an observer to appreciate the handicraft from all angles.
D: An LED beacon rotating device, comprising a rotating LED lamp (1), a magnetofluid suspended lamp base (2), a drive device (3), a rotating power connector (4) and a controller (5); the rotating LED lamp (1) comprises an LED lamp (6), an LED lamp base (7) and a crystal triple prism (8); the magnetofluid suspended lamp base (2) comprises a container (9), magnetofluid (10) and an electromagnetic coil (11); the magnetofluid (10) is disposed inside the container (9); the electromagnetic coil (11) is installed on the container (9); the drive device (3) is fixedly connected to the rotating LED lamp (1); the rotating LED lamp (1) is suspended above the magnetofluid (10) of the magnetofluid suspended lamp base (2); the controller (5) is provided with a control wire connected to the electromagnetic coil (11); the controller (5) enables the electromagnetic coil (11) to generate a magnetic field used for magnetizing the magnetofluid so as to increase the specific gravity of the magnetofluid, as well as the buoyant force of the rotating LED lamp (1) in the magnetofluid (10), so the rotating LED lamp (1) is suspended and rotates in the magnetofluid (10), reducing the rotational friction force of the rotating LED lamp (1), and reducing the driving force for driving the beacon to rotate.
Answer: C