Abstract: Disclosed are a method of measuring ESR in a sample located outside a resonator using the B1 leaking to the exterior from the end of the resonator; and an ESR device comprised of at least a resonator capable of applying a B1 leaking from the end of the resonator to a sample located outside the resonator, and a magnet located on the resonator side of a plane containing the end of the resonator that is capable of applying a B0 and a modulation field. These inventions enable ESR measurement of the interior of large samples.

Abstract: An optical connector plug includes a holder having a ferrule at one end thereof, a stop ring for supporting the ferrule in a predetermined direction, a plug frame for rotatably supporting and incorporating the stop ring in an axial direction, and a coil spring interposed between the holder and the stop ring, for energizing the ferrule to the front in the plug frame, wherein the holder and the stop ring have engaging portions with which they are mutually engaged, and an optical axis of the ferrule is adjusted in a single step by rotating the stop ring and fixing the plug frame or by rotating the plug frame and fixing the stop ring, and an adjusted position is fixed by pressure generated by pressing the spring to the holder and by using an adhering agent which is filled between the plug frame and the stop ring.

Abstract: Disclosed are a method of measuring ESR in a sample located outside a resonator using the B1 leaking to the exterior from the end of the resonator; and an ESR device comprised of at least a resonator capable of applying a B1 leaking from the end of the resonator to a sample located outside the resonator, and a magnet located on the resonator side of a plane containing the end of the resonator that is capable of applying a B0 and a modulation field. These inventions enable ESR measurement of the interior of large samples.

Abstract: An optical connector plug includes a holder having a ferrule at one end thereof, a stop ring for supporting the ferrule in a predetermined direction, a plug frame for rotatably supporting and incorporating the stop ring in an axial direction, and a coil spring interposed between the holder and the stop ring, for energizing the ferrule to the front in the plug frame, wherein the holder and the stop ring have engaging portions with which they are mutually engaged, and an optical axis of the ferrule is adjusted in a single step by rotating the stop ring and fixing the plug frame or by rotating the plug frame and fixing the stop ring, and an adjusted position is fixed by pressure generated by pressing the spring to the holder and by using an adhering agent which is filled between the plug frame and the stop ring.

Abstract: A magnetic disc cartridge comprising: a support disc which carries at least one magnetic disc on its circumference; a magnetic disc housing case having an opening through which at least one magnetic head enters; a closure mechanism for covering said opening; and a holding mechanism which holds said support disc down on a base member of said housing case. The support disc has at least one hole in its hub through which circulating clean air flows in. A cover for said hole is arranged cooperating with said closure mechanism so that said cover opens when said closure mechanism opens and closes when said closure mechanism closes.