We are specialized in the screw air compressor, oil injected screw compressor, variable frequency oil injected screw compressor, oil-free screw air compressor, Greenair freeze drier, Greenair adsorption drier, related spare parts and maintenance mat
The Principal Pitches and Principal Screws of Screw Systems，赵景山，周海欣，This paper investigates the principal screws and their pitches of screw systems from the viewpoint of line geometry. It starts from the fact that any independent screws pertainin
Accurate placement of pedicle screw (PS) is crucial in spinal surgery. Developing new real-time intra-operative monitoring and navigation methods is an important direction of clinical application research. In this paper, we studied the spectrum along
