Abstract: There are provided an intermetallic-compound superconductor that is high in superconducting transition temperature, and an alloy superconductor that is high in superconducting transition temperature and excels in malleability and ductility, as well as a method of making such a superconductor with good reproducibility and at a low cost of manufacture. This entirely new intermetallic compound superconductor is made of magnesium (Mg) and beryllium (Be) and has a chemical composition expressed by formula: Mg1Be2, has a hexagonal AlB2 type crystallographic structure and has a superconducting transition temperature (Tc) of 35 K. An alloy containing this intermetallic compound excels in malleability and ductility and constitutes the alloy superconductor having a superconducting transition temperature (Tc) of 35 K and being low in specific resistance for normal conduction at a temperature ranging from the superconducting transition temperature to a room temperature.

Abstract: Hollow polymer particles are provided to have an average particle diameter of 15 &mgr;m or more and 500 &mgr;m or less and a 10%-compressive strength of 1.5 MPa or more, and the hollow polymer particle includes a hollow portion in the interior. In addition, a porous ceramic filter is provided by firing a shaped material composed of a mixture in which the above-described hollow polymer particles are mixed to disperse in a ceramic composition.

Abstract: A method of producing a thermally expansive microcapsule that is excellent in heat resistance and solvent resistance, narrow in breadth of the distribution of particle size, and extremely low in secondary cohesion of the particles when heated, wherein a polymer obtained from the component comprising not less than 80 weight % of monomer of nitrile series, less than weight % of monomer of non-nitrile series, and 0.05-1 weight % of at least tetrafunctional cross-linking agent and/or of long side chain of cross-linking agent is used to micro-encapsulate a volatile expanding agent that comes into its gaseous state at a temperature equal to or less than a softening point of the polymer.