Abstract: A superconductive wire wherein the superconductive wire has a core portion containing magnesium diboride as the main component and a continuous metallic sheath firmly adhered to the core portion; the core portion is kept substantially vacuum; and the content of an inert gas such as an Ar gas contained in the core portion is in the range of 0.00002 to 10 ppm. Further, disclosed is a method for producing a superconductive wire, wherein the method comprises the steps of mixing powder of a source material constituting magnesium diboride to form a core portion of the superconductive wire in an inert gas, filling a pipe with the mixed material powder in vacuum environment, sealing the pipe with vacuum after filled with the material powder, forming magnesium diboride powder by heating the vacuum-sealed pipe (sheath), and forming the core portion by wiredrawing the pipe in the state where the magnesium diboride powder is sealed with vacuum, and the core portion firmly sticks to the wiredrawn metallic pipe.

Abstract: An antenna coil is formed by a wire rod obtained by combining and integrating two or more kinds of materials having different magnetisms. The wire rod has a circular or polygonal cross sectional shape. The two or more kinds of materials having different magnetisms are combined so that the magnetisms of the combined materials are set off. The wire rod is wound around a bobbin so as to have a solenoid shape. Desirably, the low-magnetic wire rod is placed in an atmosphere whose temperature has been reduced to 10° K or less or superconductive filaments are formed in the outermost layer. Preferably, a part of the superconductive filaments are exposed.

Abstract: An object is to provide a liquid level sensor device for liquefied gas enabling measurement on a liquid level of liquefied gas having a boiling point in the vicinity of 21 K, e.g. liquid hydrogen, accurately and with good reproducibility and enabling simple production with good reproducibility. The present invention is a liquid level sensor device for liquefied gas including compound containing magnesium and boron arranged in succession in the longitudinal direction over the entire or a part of surface of a linear conductor made of metal and a portion of the compound thereof dipped in liquid is in a superconductive state at liquid level measurement.

Abstract: There is disclosed a permanent current switch which has a high temperature margin and which is thermally stable and which securely performs a switching operation between a superconducting state and a normal conducting state. The permanent current switch of the present invention has a coiled superconducting wire and a heater wire which switches the superconducting wire between the superconducting state and the normal conducting state, the superconducting wire is a magnesium diboride superconducting wire having a high-resistance metal on an outer side and a magnesium diboride superconducting portion on an inner side and prepared by forming a superconducting metal on a layer between the high-resistance metal and the magnesium diboride superconducting portion, and the permanent current switch further comprises a superconductive connecting section superconductively connected to a lead wire guided from the superconducting wire and a superconducting wire for a wiring line.

Abstract: A method of producing an electrical connection structure between at least two superconducting lines. The method comprises adding metal powder or alloy powder to a superconducting material comprising magnesium diboride, intervening the superconducting material between at least two superconducting lines, and heating said superconducting lines and said superconducting material to a temperature lower than the melting point of said superconducting material prior to the addition of said metal powder or alloy powder thereto, but higher than the melting point of said metal powder or alloy powder.

Abstract: An object of the present invention is to provide: a superconducting wire with a boron-containing superconductor charged or included therein, the superconducting wire further being able to have a practical critical current density; a method for manufacturing the superconducting wire, and; a superconducting magnet using the superconducting wire.

Abstract: Electrical connection of superconducting lines can be achieved by using a low-melting point metal, by mechanical contact of superconducting lines or by welding. According to these methods, however, critical current and critical magnetic field at the connection point are low, and stable connection in a superconducting state has been difficult. The present invention solves these problems and provides a structure and method for connecting superconducting lines. The present invention provides high-performance, high-stability connection of superconducting lines through magnesium diboride (MgB2) powder arranged between superconducting lines.

Abstract: An MgB2 compound sheath superconducting wire includes a high stable metal having a specific electric resistance 7 &mgr;&OHgr;cm or below at a room temperature and a high strength metal having a Vickers hardness 50 or above at a room temperature, both of which are assembled therewith to realize a high strength and a lengthy superconductor.

Abstract: The invention provides a superconducting wire rod which is filled with or interiorly includes a superconductor containing a boron, wherein the superconducting wire rod has a practical critical electric density even under a magnetic field. In a superconducting wire rod filled with or interiorly including a superconductor containing a boron, a metal powder is added to a superconducting material included in the superconducting wire rod, the metal powder is selected from at least one of an indium, a tin, a lead, an iron, a magnesium and an aluminum, the metal power having an average grain diameter equal to or less than 20 &mgr;m is 5 to 25 vol % dispersed in the superconducting material, a density of the superconducting material included in the superconducting wire rod after a final work is equal to or more than 90% a theoretical density, and a critical current density is equal to or more than 1000 A/cm2.

Abstract: The cross section of a wire is round and is composed of several units, each consisting of tape-like superconductors laminated in an approximately rhombic shape, which are arranged such that they form a hexagon as a whole. Oxide superconducting tape wires each consisting of a plurality of oxide superconducting filaments are arranged in rotational symmetry to a core. The oxide superconducting filaments have the cross section such that the average thickness is 3 to 20 &mgr;m and the average aspect ratio is larger than 2 and smaller than 10. A step of arranging the oxide superconducting tape-like wires in rotational symmetry is accomplished when the multi-core tape-like wires are packed in a third metal pipe which becomes a metal sheath later. Since the multi-core tape wires having oxide superconducting filaments are arranged in rotational symmetry, the oxide superconductor in the oxide superconducting filaments permits its c axis to orient in various directions.

Abstract: Electrical connection of superconducting lines can be achieved by using a low-melting point metal, by mechanical contact of superconducting lines or by welding. According to these methods, however, critical current and critical magnetic field at the connection point are low, and stable connection in a superconducting state has been difficult. The present invention solves these problems and provides a structure and method for connecting superconducting lines. The present invention provides high-performance, high-stability connection of superconducting lines through magnesium diboride (MgB2) powder arranged between superconducting lines.

Abstract: The cross section of a wire is round and is composed of several units, each consisting of tape-like superconductors laminated in an approximately rhombic shape, which are arranged such that they form a hexagon as a whole. Oxide superconducting tape wires each consisting of a plurality of oxide superconducting filaments are arranged in rotational symmetry to a core. The oxide superconducting filaments have the cross section such that the average thickness is 3 to 20 &mgr;m and the average aspect ratio is larger than 2 and smaller than 10. A step of arranging the oxide superconducting tape-like wires in rotational symmetry is accomplished when the multi-core tape-like wires are packed in a third metal pipe which becomes a metal sheath later. Since the multi-core tape wires having oxide superconducting filaments are arranged in rotational symmetry, the oxide superconductor in the oxide superconducting filaments permits its c axis to orient in various directions.

Abstract: Electrical connection of superconducting lines can be achieved by using a low-melting point metal, by mechanical contact of superconducting lines or by welding. According to these methods, however, critical current and critical magnetic field at the connection point are low, and stable connection in a superconducting state has been difficult. The present invention solves these problems and provides a structure and method for connecting superconducting lines. The present invention provides high-performance, high-stability connection of superconducting lines through magnesium diboride (MgB2) powder arranged between superconducting lines.

Abstract: A process for producing adipic acid is provided which comprises a step of oxidizing hydroxycaproic acid and/or &egr;-caprolactone with oxygen or oxygen-containing gas using a metal in the platinum group as a catalyst. According to the process, adipic acid is produced without using nitric acid, which becomes the main factor responsible for the by-production of nitrogen oxides, and without using any particularly high-pressure conditions.

Abstract: A method for manufacturing an oxide superconducting coil can suppress deterioration of superconducting characteristics caused by a strong electromagnetic force and deformation and a reaction during heat treatment. The oxide superconducting coil is manufactured by a wind-and-react (W&R) method using a metal sheathed oxide superconducting wire material and an insulator, wherein an oxide film formed on a surface of a heat resistant alloy during a heat treatment is used for insulating the coil, and the heat resistant alloy has a sufficient strength to prevent the deformation of the coil generated by the weight of the coil itself during the heat treatment and to endure a strong electromagnetic force. An oxide superconducting coil operable with a coolant, such as liquid nitrogen, liquid helium, and the like, or a refrigerator, can be realized.

Abstract: Structure for joining together metal-coated multi-core oxide superconductor wire material parts in a tape shape. The C axis of a oxide superconductor crystal is substantially oriented along the longitudinal (length) direction that the wire material extends. The end faces of the wire material parts contact each other at the joint part; and the C face of the oxide superconductor crystal is continuously oriented at the joint part.

Abstract: This invention provides an oxide-type superconducting flat wire having a critical current density of at least 1,000 A/cm.sup.2, which comprises a Y--Ba--Cu oxide layer having a superconducting property and a silver layer surrounding the oxide layer and has so flat a cross section vertical to the longitudinal direction of the wire that the upper and lower lines between the oxide layer and the silver layers appearing on the cross section having a zone over they are parallel to each other, the thickness of the oxide layer being cold rolled in the range of 0.35 to 0.75 based on the whole thickness of the wire, the whole thickness being 0.2 mm or less, and the metal layer being deformable to follow the shrink deformation of the oxide layer when heat treated to be sintered, but rigid when used.

Abstract: An elongate superconductor wiring element having, as seen in section, oxide superconductor material regions in each of which the c-axes of the oxide superconductor crystals are aligned with each other and are transverse to the longitudinal axis of the element. To reduce the dependence of critical current density on angular position of the element relative to a magnetic field, there are a plurality of said regions whose alignment directions of the c-axes are different as between different ones of said regions, so that the wiring element comprises a plurality of said regions having respectively different c-axis alignment directions.

Abstract: A superconductive material has the formula(Tl.sub.1-X1-X2 Pb.sub.X1 Bi.sub.X2).sub..alpha. (Sr.sub.1-X3 Ba.sub.X3).sub..beta. Ca.sub..gamma. Cu.sub..delta. O.sub..xi.where0.ltoreq.X1.ltoreq.0.80.ltoreq.X2.ltoreq.0.50.ltoreq.X3.ltoreq.1.00.7.ltoreq..alpha..ltoreq.1.51.4.ltoreq..beta..ltoreq.3.00.7.ltoreq..gamma..ltoreq.4.51.4.ltoreq..delta..ltoreq.64.5.ltoreq..xi..ltoreq.170<X1+X2<1.The superconducting material may be combined with an isostructural non-superconducting material, which then acts as a pinning center. The result may also be combined with a metal. The resulting superconductor permits a high critical current density Jc to be obtained, even at relatively high magnetic flux densities.

Abstract: A superconductive material has the formula(Tl.sub.1-X1-x2 Pb.sub.X1 Bi.sub.X2).sub..alpha. (Sr.sub.1-X3 Ba.sub.X3).sub..beta. Ca.sub..gamma. Cu.sub..delta. O.sub..zeta.where0.ltoreq.X1.ltoreq.0.80.ltoreq.X2.ltoreq.0.50.ltoreq.X3.ltoreq.1.00.7.ltoreq..alpha..ltoreq.1.51.4.ltoreq..beta..ltoreq.3.00.7.ltoreq..gamma..ltoreq.4.51.4.ltoreq..delta..ltoreq.64.5.ltoreq..zeta..ltoreq.170<X1+X2<1.The superconducting material may be combined with an isostructural non-superconducting material, which then acts as a pinning center. The result may also be combined with a metal. The resulting superconductor permits a high critical current density Jc to be obtained, even at relatively high magnetic flux densities.