Abstract: A coaxial speaker includes a frame, a vibration system, and a magnetic circuit system. The vibration system includes a vibrating diaphragm and a voice coil. The magnetic circuit system includes a transmission cavity, an inner magnetic gap, and an outer magnetic gap. The inner magnetic gap includes a first magnetic gap and a second magnetic gap. The transmission cavity penetrates through the magnetic circuit system. The vibrating diaphragm includes a first vibrating diaphragm, a second vibrating diaphragm, and a third vibrating diaphragm. The third vibrating diaphragm and the first vibrating diaphragm reversely vibrate. The first vibrating diaphragm and the third vibrating diaphragm seal the transmission cavity. The voice coil includes a first voice coil, a second voice coil, and a third voice coil. The coaxial speaker effectively reduces sound leakage of a front receiver during working, and realizes a private call function.

Abstract: A tunnel tunneling system includes a bolter miner, a bolter-integrated transportation machine, a transfer machine, a self-moving tail and a belt conveyor. The bolter miner includes a rack, a cutting device, a drilling device and a control device. The cutting device is arranged on the rack and is swingable in an up-down direction, and has a lowest swing angle and a highest swing angle. The drilling device is arranged on the rack, and includes a drilling rig and a sensor. The drilling rig is configured to drill a tunnel floor and/or a tunnel roof, and the sensor is configured to monitor a set parameter of the drilling rig and generate a monitoring data signal when the drilling rig is drilling. The control device is configured to receive and analyze the monitoring data signal.

Abstract: A tire self-positioning system and a positioning method therefor. The tire self-positioning method includes the steps of: S1, data acquisition; S2, data conversion; S3, data compensation; S4, data statistics; S5, determining, according to a statistical result, a specific position of a tire corresponding to the first signal. The tire self-positioning system and positioning method therefor are used to solve the problem of a tire experiencing reverse movement, and increase the success rate of active learning.

Abstract: Disclosed are a refrigerator and a door assembly therefor; the door assembly includes two oppositely arranged doors and a turnover beam assembly, wherein the turnover beam assembly includes: a turnover beam body; a guide part extending out of one end of the turnover beam body and configured to be fitted with a retainer provided on a cabinet of the refrigerator; a locking part telescopically provided in the turnover beam body and having a first end fixedly connected with the guide part and a second end having a locking portion, the locking part having an unlocking state and a locking state. In the present invention, an anti-turnover function of the turnover beam body is achieved using the locking part and the elastic part, which improves coordination among all components, makes an internal structure of the turnover beam assembly more reasonable, achieves high practicability, and realizes easy popularization.

Abstract: The present invention discloses a refrigerator door with a replaceable door surface, including: a foamed door body and a door shell plate; wherein a rear side of the door shell plate is provided with a hook; a front side of the foamed door body is provided with a press lock catch, which comprises a snap tab; and when the door shell plate is assembled on the front side of the foamed door body, the hook is snapped into the snap tab to limit the displacement of the door shell plate in a front-rear direction. In the present invention, the locking or unlocking between the hook and the snap tab is achieved by rotating the snap tab, which is rotatable in the press lock catch, between the first position and the second position, such that the door shell plate and the foamed door body are more convenient to assemble and disassemble.

Abstract: The present invention discloses a refrigerator door with a replaceable door surface, including: a foamed door body and a decorative door plate; wherein a rear side of the decorative door plate is provided with a mating member; a front side of the foamed door body is provided with a magnetic lock catch, which comprises a plurality of balls; By clamping the mating member on the rear side of the decorative door plate by the plurality of balls of the magnetic lock catch in the foamed door body, the displacement of the decorative door plate in the front-rear direction is limited. In addition, the unlocking magnetic buckle is provided to repel with the magnetic ring, such that a locking relationship between the plurality of balls and the mating member is released, thereby achieving the effect of quickly disassembling and installing the decorative door plate.

Abstract: The present invention provides a refrigerator door with a replaceable door panel, comprising: a door body and a decorative door panel detachably connected to the door body; a rotary latch and a limiting member are disposed on the door body; a rear side of the decorative door panel facing towards the door body comprises a second limiting member and a lock post wherein when the decorative door panel is assembled on a front side of the door body, the rotary latch and the lock post snap-fit each other to limit a displacement of the decorative door panel in an up-down direction; the first limiting member cooperates with the second limiting member to limit a displacement of the decorative door panel in a front-rear direction.

Abstract: The present invention provides a refrigerator door body, provided with a door liner and a storage device mounted on the door liner; a hanging lug and a fitting groove which fit each other are provided between the door liner and the storage device, a power supply module is provided, in a fitting manner, between the hanging lug and the fitting groove, the power supply module comprises a first connector provided on the hanging lug and a second connector provided at the fitting groove, and the first connector and the second connector are connected to each other in a fitting manner when the storage device is mounted. The refrigerator door body of the present invention not only can function to support the storage device, but also can function to supply power to the storage device.

Abstract: Methods and systems of producing perovskite material, in which the nucleation and crystallization processes are decoupled and, hence, independently controlled resulting in highly uniform nucleation sites for subsequent crystallization of perovskites. Methods and systems for using perovskite material and mixed perovskite films for solar cells.

Abstract: Methods and systems of producing perovskite material, in which the nucleation and crystallization processes are decoupled and, hence, independently controlled resulting in highly uniform nucleation sites for subsequent crystallization of perovskites. Methods and systems for using perovskite material and mixed perovskite films for solar cells.