Abstract: The present disclosure provides an electrostatic nozzle and a controllable jet minimal quantity lubrication (MQL) grinding system. The electrostatic nozzle comprises a nozzle core; an upper nozzle body is connected above the nozzle core; a free space is formed between the upper nozzle body and the nozzle core for storing compressed air and reducing pressure; a lower nozzle body is connected below the nozzle core; a gas-liquid mixing chamber, an acceleration chamber and a nozzle outlet are sequentially arranged inside the nozzle core from top to bottom; and micro-bulges are uniformly distributed on an inner wall of the acceleration chamber.

Abstract: A hydraulic support unit and a hydraulic support for anti-rock burst roadway. The hydraulic support unit includes a base, a top beam, and a hydraulic support column, the top beam is positioned above the base in a spaced manner; the hydraulic support column are disposed between the base and the top beam; a side guard plate and a first base hydraulic cylinder are disposed on the left side and right side of the base, the side guard plates are rotably connected to the base, the two ends of the first base hydraulic cylinder are hinged to the base and the side guard plate respectively, the first base hydraulic cylinder can drive the side guard plate to transit between a horizontal state and a vertical state, and the bottom surfaces of the side guard plates are flush with the bottom surface of the base in the horizontal state.