Abstract: The superconducting structure for magnetic shielding according to the present invention comprises at least two layers of a superconducting layer and a substrate. This superconducting structure for magnetic shielding can be formed in a plate-like shape or a cylindrical shape. When the structure is prepared in three-layers by providing an intermediate layer between the superconducting layer and the substrate, the three-layered structure has improved superconducting properties. When a protective layer is provided on the superconducting layer to protect the layer, the resulting structure has improved thermal shock resistance. The intermediate layer preferably consists of a ceramic or a noble metal and the ceramic preferably consists of a glass.

Abstract: The present process for producing a Bi-based superconducting oxide includes the steps of molding a material powder and subjecting the molded article to partial melting and then to crystallization in the presence of oxygen. In that case, the molded article is annealed, after the partial melting, to the crystallization temperature and subjected to crystallization at that temperature. Also, the article after the crystallization is cooled and the cooled article is heat-treated in an inert gas atmosphere. According to the above process, there can be obtained a Bi-based superconducting oxide having excellent superconducting properties.

Abstract: An oxygen sensor element including an oxygen ion conductive solid electrolyte body, and electrode layers formed on opposite surfaces of the oxygen ion conductive solid electrolyte body. The electrode layers are mainly constituted by a platinum group metal in which a refractory material is dispersed.

Abstract: The invention provides an oxygen sensor for detecting oxygen concentration in exhaust gas from an internal combustion engine. The oxygen sensor comprises a closed-end tube of solid electrolyte having an inside reference electrode communicating with the atmosphere and an outside measuring electrode which is exposed to the exhaust gas, a housing to support the tube, a metallic sleeve fixed to the housing to isolate the reference electrode from the exhaust gas, while atmospheric air is allowed to enter into the tube through air passages on the metallic sleeve. The passages are protected by a filter securely fixed to the metallic sleeve, pressed by an elastic member thereagainst, whereby water or mud are prevented from entering into the tube while the sensor is operating.

Abstract: A process of manufacturing an oxygen sensor having an oxygen sensing element which includes an oxygen-ion conductive solid electrolyte body, a plurality of electrodes on the solid electrolyte body, and a porous ceramic protective layer which covers the electrode disposed on the side of a measurement gas, to protect the electrode from direct exposure to the measurement gas. The process comprises a step of heat-treating at least a portion of the ceramic protective layer covering the electrode, in a reducing atmosphere. The heat-treatment improves an operating response of the sensor over the entire range of temperature of the measurement gas.

Abstract: An oxygen sensor having a high reliability without penetration of water is disclosed. The oxygen sensor has a solid electrolyte consisting of a tubular body closed at its one end, having inner and outer electrodes, and received gastightly in a housing; a center conductor pressed and electrically connected to the inner surface electrode by a pressing force of a spring; an outwardly extended rim formed at the end portion of a tubular connecting terminal, which penetrates through a first insulating body supported by the upper end of a metallic container connected to the housing and is connected to the center conductor through a conductor; and a second insulating body which is slidable with respect to the metallic container and is arranged between another end of the above described spring, which is connected at its one end to the center conductor having the same potential as that of the inner electrode, and the rim of the connecting terminal.

Abstract: An oxygen sensing device in which a tubular solid electrolyte, one end of which is closed, is applied with electrodes on the outer and inner surfaces, the closed end side of the solid electrolyte is exposed to combustion gases exhausted from internal combustion engines, the inner electrode and the outer electrode are contacted with ambient air and the combustion gases respectively, is characterized in that an inner surface of a tubular solid electrolyte is constructed of a wide opening portion, a first diameter reducing portion connecting to said wide opening portion, an intermediate wide opening portion having a uniform diameter which is smaller than the wide opening portion, and connecting to the first diameter reducing portion, a second diameter reducing portion connecting to the intermediate wide opening portion and a narrow opening portion connecting to the second diameter reducing portion which extends to the closed end.