Abstract: The present disclosure relates to a single-power lifting and folding mechanism and a piece of furniture. The single-power lifting and folding mechanism includes a first lifting mechanism, a second lifting mechanism, a first flexible rope, and a driving device, wherein the first lifting mechanism includes a first movable component and a first fixed component, the second lifting mechanism includes a second movable component and a second fixed component, one end of the first flexible rope is fixedly connected to the first fixed component, the other end of the first flexible rope is fixedly connected to the second fixed component, the second fixed component is provided with the driving device, and the driving device abuts against a rotating shaft of the third movable pulley directly or indirectly and subsequently tensions the first flexible rope.

Abstract: An automatic leveling device of a 3D printer, and a 3D printer is provided. The automatic leveling device includes a photoelectric switch, an electromagnetic assembly and a probe assembly. The photoelectric switch is arranged in a housing and defines a photosensitive groove. The electromagnetic assembly is arranged in the housing and defines a sliding hole. The probe assembly is slidably engaged in the sliding hole, and an end of the probe assembly is engaged in the photosensitive groove. The electromagnetic assembly is capable of driving the probe assembly to make the end of the probe assembly move out of the photosensitive groove. The automatic leveling device has the advantages of simple structure, low manufacturing difficulty, low production cost, simple and stable leveling mode, high detection repetition accuracy and no complex circuit and software cooperation.

Abstract: An automatic leveling device of a 3D printer, and a 3D printer is provided. The automatic leveling device includes a photoelectric switch, an electromagnetic assembly and a probe assembly. The photoelectric switch is arranged in a housing and defines a photosensitive groove. The electromagnetic assembly is arranged in the housing and defines a sliding hole. The probe assembly is slidably engaged in the sliding hole, and an end of the probe assembly is engaged in the photosensitive groove. The electromagnetic assembly is capable of driving the probe assembly to make the end of the probe assembly move out of the photosensitive groove. The automatic leveling device has the advantages of simple structure, low manufacturing difficulty, low production cost, simple and stable leveling mode, high detection repetition accuracy and no complex circuit and software cooperation.

Abstract: The present invention provides a Streptococcus, which is a new species of the genus of Streptococcus, named as Streptococcus sp. 121, and is registered and deposited in GuangDong Microbial Culture Collection Center with the accession number of GDMCC No: 61195. After fermentation culture, the Streptococcus sp. 121 of the present invention can produce a stronger bacteriostatic active substance, which has relatively obvious antimicrobial effects on Klebsiella pneumoniae, Shigella dysenteriae, and the like, has a broad development space in prevention and treatment of diseases caused by Klebsiella pneumoniae and Shigella dysenteriae, and has a very good development and application prospect in antimicrobial drugs.

Abstract: The invention provides a system for calcining active lime, including a precalcining furnace for receiving limestone materials to be calcined and precalcining the limestone materials, and a rotary kiln for receiving the materials containing precalcined product from the precalcining furnace, outputting the formed active lime, and at the same time supplying a first flue gas to the precalcining furnace. The calcining system further includes a precalcining furnace combustion device, which generates a second flue gas and supplies it to the precalcining furnace, such that the limestone materials are precalcined in the precalcining furnace under the action of the first flue gas and the second flue gas. In this way, the precalcining rate of the limestone materials in the precalcining furnace is significantly improved.

Abstract: An electronic device having a rotatable support is provided. A main body includes a first cylindrical engaging hole with a plurality of first internal gear teeth. A support body includes a second cylindrical engaging hole with a plurality of second internal gear teeth. A gear includes a first portion inserted in the first engaging hole and engaging with the first internal gear teeth, and a second portion inserted in the second engaging hole and engaging with the second internal gear teeth, to restrict the support body from rotating with respect to the main body. A spring member is compressed between the gear and main body in the first engaging hole, to urge the gear to move away from the main body. A button depressibly mounted on the support body is depressed to move the gear out of the second engaging hole, thereby disengaging the support body from the gear.

Abstract: An electronic device having a rotatable support is provided. A main body includes a first cylindrical engaging hole with a plurality of first internal gear teeth. A support body includes a second cylindrical engaging hole with a plurality of second internal gear teeth. A gear includes a first portion inserted in the first engaging hole and engaging with the first internal gear teeth, and a second portion inserted in the second engaging hole and engaging with the second internal gear teeth, to restrict the support body from rotating with respect to the main body. A spring member is compressed between the gear and main body in the first engaging hole, to urge the gear to move away from the main body. A button depressibly mounted on the support body is depressed to move the gear out of the second engaging hole, thereby disengaging the support body from the gear.