Abstract: According to one embodiment, a process for producing rare metals includes the steps of: electrolyzing an electrolytic solution to extract a Re oxide at a cathode; recovering the Re oxide, and electrolyzing the Re oxide in a molten salt electrolyte to extract metallic Re; recovering a Nd containing residue solution; treating the Nd containing residue solution to produce Nd oxide; electrolyzing the Nd oxide in a molten salt electrolyte to extract metallic Nd; recovering a Dy containing residue solution; treating the Dy containing residue solution to produce Dy oxide; and electrolyzing the Dy oxide in a molten salt electrolyte to extract metallic Dy.

Abstract: According to one embodiment, a process for producing rare metals includes the steps of: electrolyzing an electrolytic solution to extract a Re oxide at a cathode; recovering the Re oxide, and electrolyzing the Re oxide in a molten salt electrolyte to extract metallic Re; recovering a Nd containing residue solution; treating the Nd containing residue solution to produce Nd oxide; electrolyzing the Nd oxide in a molten salt electrolyte to extract metallic Nd; recovering a Dy containing residue solution; treating the Dy containing residue solution to produce Dy oxide; and electrolyzing the Dy oxide in a molten salt electrolyte to extract metallic Dy.

Abstract: The superconducting magnet apparatus includes a cryostat, a superconducting coil provided in the cryostat, and a current lead having a portion made of an oxide superconductor, for supplying a current to the superconducting coil. The portion of the current lead which is made of the oxide superconductor has a high-temperature end and a low-temperature end, and the current lead is arranged such that the direction of a current flow in at least the high-temperature end and the direction of a leakage magnetic flux applied from the superconducting coil to the high-temperature end are made substantially in parallel to each other.

Abstract: A bobbin for superconducting coils, which is made of a fiber-reinforced plastic material containing: (1) a matrix resin; (2) a polyethylene fiber having a negative thermal expansion coefficient in the fiber lengthwise direction, the angle between the polyethylene fiber and the longitudinal axis of the bobbin being in the range of .+-.35.degree. to 90.degree.; and (3) a substance having an elastic modulus higher than that of the polyethylene fiber. The bobbin of the present invention is useful for superconducting coils because it only exhibits a quite low degree of deformation, even when used under external stress at cryogenic temperatures.

Abstract: An insulating composition consisting of Bi, Sr, RE, Cu, O or of Tl, Ba, RE, Cu, O (wherein; RE is an element selected from a group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) aligns properly with a crystal face of an oxide superconductor because its crystal structure is the same as or similar to that of the oxide superconductor. An insulating composition in which a part of Bi is replaced by Pb is further near the oxide superconductor its construction, and the modulation structure in this insulating composition is mitigated or disappears.

Abstract: An insulating composition consisting of Bi, Sr, RE, Cu, O or of Tl, Ba, RE, Cu, O (wherein; RE is an element selected from a group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) aligns properly with a crystal face of an oxide superconductor because its crystal structure is the same as or similar to that of the oxide superconductor. An insulating composition in which a part of Bi is replaced by Pb is further near the oxide superconductor its construction, and the modulation structure in this insulating composition is mitigated or disappears.

Abstract: The magnetic field sensor is described for sensing the magnetic field, which comprises a light source part, a magnetic field detection part which contains a magnetooptic element consisting of a magnetic materials having a magnetooptic effect, and a light measurement part which measures the light that has been radiated from the light source part and has passed through the magnetic field detection part, is characterized in that the magnetooptic element is arranged such that its easy axis of magnetization is at substantially right angles to the direction of the magnetic field to be measured. The sensor can measure in a wide range of magnetic field with a high degree of accuracy and high sensitivity.

Abstract: A process for producing a signal crystal of garnet ferrite comprises causing a signal crystal to grow by subjecting raw materials for the garnet ferrite to sintering so as to utilize the anomalous grain growth induced by the sintering. The process requires a shorter period of time for the growth of the single crystal, is free from mixing of impurities, and is capable of producing a single crystal with a high Faraday rotation while reducing production cost for the crystal.

Abstract: A PTC ceramic composition comprising a fundamental component represented by the formula:(V.sub.1-x A.sub.x).sub.2 O.sub.3wherein x is a value within the range of 0.ltoreq.x.ltoreq.0.02 and A is at least one of Cr and Al, and tin in an amount of 1 to 25 % by weight based on the total weight of the composition, has a small electric resistance in the low resistance state, good PTC properties, and a high density.