Abstract: A nuclear magnetic resonance apparatus including: a cup-shaped high-temperature superconductor 20 having a hollow cylindrical shape or portion cooled to not more than a superconducting transition temperature in a vacuum insulating container 22; and a detection coil 12 for detecting an NMR signal of a material 11 to be measured inserted into the hollow cylindrical portion 20a of the high-temperature superconductor. The high-temperature superconductor is magnetized in an axial direction, a static magnetic field is thereby generated in the hollow cylindrical portion in a cylinder axial direction, and the NMR signal of a material is detected by the detection coil and the existing spectrometer. A strong static magnetic field comparable to a conventional superconducting magnet is formed without using a refrigerant (liquid helium) essential for operating the conventional superconducting magnet, and a strength distribution of the static magnetic field is homogeneous.

Abstract: There is disclosed a nuclear magnetic resonance apparatus comprising: a cup-shaped high-temperature superconductor 20 having a hollow cylindrical shape or portion cooled at a temperature not more than a superconducting transition temperature in a vacuum insulating container 22; and a detection coil 12 for detecting an NMR signal of a material 11 to be measured inserted into the hollow cylindrical portion 20a of the high-temperature superconductor. The high-temperature superconductor is magnetized in an axial direction, a static magnetic field is thereby generated in the hollow cylindrical portion in a cylinder axial direction, and the NMR signal of the material to be measured disposed in the magnetic field is detected by the detection coil and the existing spectrometer.

Abstract: A cold accumulator filled with a cold accumulating material including 20 to 95 at % of at least one element selected from the group consisting of cerium (Ce), neodymium (Nd), praseodymium (Pr), magnetic body dysprosium (Dy), holmium (Ho), erbium (Er) and thulium (Tm), and 5 to 80 at % of an additive containing at least silver (Ag), thereby improving the specific heat at 10 to 30 K. The cold accumulating material can increase the efficiency of heat accumulating at 10 to 30 K, and the cold accumulator can be applied to refrigerators which generate refrigeration at cold low temperatures of 10 to 30 K.

Abstract: An Nd-Ba-Cu-O bulk superconductor includes oxide including metallic elements of neodymium (Nd), barium (Ba) and copper (Cu), and has a structure in which fine particles of Nd.sub.4 Ba.sub.2 Cu.sub.2 O.sub.10 (i.e., Nd422) are dispersed uniformly in crystalline grains of NdBa.sub.2 Cu.sub.3 O.sub.x (i.e., Nd123). It is produced by preparing a mixture powder in which an Nd123 powder and an Nd422 powder are present uniformly, thermally treating the mixture powder in a temperature range where the Nd123 powder melts partially at least but the Nd422 powder hardly melts, and gradually cooling the partially melted mixture powder in a temperature range around a solidifying point of the Nd123 powder. It exhibits an enhanced magnetic-field-trapping capability in the regions of low magnetic field, because of the pinning effect resulting from the fine particles of Nd422 dispersed uniformly in the crystalline grains of Nd123.

Abstract: The graphite is a composite between graphite particles and other fine, solid element particles, in which the graphite particles account for at least 40 atomic % and the other element particles have particle sizes of 900 nm or smaller and are dispersed in said graphite particles. The other elements may be Li and Si. Preferably, a part of said other elements forms an intercalation compound with graphite. The composite is suitable for a negative electrode of lithium secondary batteries having large discharging capacity, and as adsorbent materials of adsorbing various substances.

Abstract: A superconductive ceramic composite material with high strength and capable of plastic deformation is prepared by mixing and sintering a superconductive powder represented by (RE.sub.x AE.sub.1-x).sub.1-y Cu.sub.y O.sub.z (RE represents Y or a rare-earth element having an atomic number of 57-71, or a combination of at least two of these elements, AE is at least one of alkaline earth elements Ca, Sr and Ba, x is 0.13-0.67, y is 0.25-0.67, and z is 1.08-1.17) and a metal powder M (M represents at least one of noble metals Rh, Pd, Ag, Ir, Pt and Au), in a defined ratio. The deformation (e.g., rolling) is followed by reheat-treatment (resintering). The powder mixture can be enclosed in a metallic capsule or made into a clad sheet by interposing the powder within two metallic sheets, and deformed (drawn or press formed into a desired shape) followed by sintering. The composite material may contain a superconductive network of such grains.

Abstract: Disclosed herein is an amorphous material in the form of foil for the regenerator, which is prepared by quenching a melt of a rare earth alloy by injection toward the surface of a roll running at a high speed, said alloy being composed of one or more rare earth elements in an amount of 50-99 atomic %, with the remainder being one or more iron family elements. This amorphous material has a large, stable specific heat capacity at very low temperatures.

Abstract: A method for producing iron-nitride powder comprises the steps of introducing iron powder and NH.sub.3 gas or N.sub.2 gas in a vessel, and milling the iron powder in the NH.sub.3 gas or the N.sub.2 gas. Furthermore, a method for producing iron-nitride powder comprises the steps of introducing iron powder and intermetallic compound powder of iron and nitrogen in a vessel, and milling the iron powder and the intermetallic compound powder. The obtained iron-nitride powder consists essentially 85.1 to 99 at % of iron and the rest of nitrogen, and has a body centered cubic structure.

Abstract: A level gauge for liquid helium suitable for use under a higher vapor pressure comprising a sensing element in the form of a ribbon wire made of superconductive alloys and a tube supporting the sensing element which tube is inserted into liquid helium upon measurement. Chemical composition of the superconductive alloys are represented by a formula, Zr.sub.100-x (Ru.sub.1-y Rh.sub.y).sub.x, in which x represents a content of Ru and/or Rh in atomic % and in a numerical value of 17.0.ltoreq.x.ltoreq.22.5 and y represents a numerical value of .ltoreq.y.ltoreq.1. The alloys are made of an amorphous phase obtained by rapid quenching of a molten alloy material and have a superconducting transition temperature, Tc, of 4.5.degree. to 5.2.degree. K.

Abstract: Improved liquid helium level gauge is described. The gauge includes a resistance wire sustained vertically within a liquid helium container and an electrical indicating device for producing an indication which varies with the electric resistance of said resistance wire. The resistance wire is made of a new superconductive amorphous material such as Zr.sub.80 Nb.sub.5 Al.sub.8 Si.sub.7. The amorphous material has a superconductivity transition temperature between 4.2.degree. and 5.0.degree. K., a relatively high normal electric resistance and a high mechanical strength.