Abstract: A compressor includes a casing having an oil reservoir, a cylinder situated within the casing, a cylindrical rotary body situated eccentrically within the cylinder, the rotary body having first and second spiral grooves extending in opposite directions from the middle part of the rotary body to both ends of the rotary body, first and second spiral blades fitted in the first and second spiral grooves, the blades having outer peripheral surfaces brought into contact with the inner peripheral surface of the cylinder, dividing the space defined by the inner peripheral surface of the cylinder and the rotary body into a plurality of working chambers, thereby constituting first and second compression sections, wherein the first and second blades freely project from and retreat in the first and second spiral grooves in the radial direction of the rotary body, driving means for rotating the cylinder and the rotary body relative to each other, a first refrigerant passage formed in the rotary body and opening to an area

Abstract: A magnetic recording medium in which a silicon nitride film is formed on a magnetic recording layer having an axis of easy magnetization in the direction essentially perpendicular to its own layer surface. The magnetic recording layer is a metallic magnetic film such as a Co-Cr containing alloy. The silicon nitride film is preferably in a state in which the number of nitrogen atoms is less than four thirds of the number of silicon atoms. A lubricant layer such as a layer of fluorocarbon can be formed on the silicon nitride film.