Abstract: A cathode-ray tube phosphor is manufactured by coating, on the surfaces of phosphor particles, a mixture of a metal alginate containing at least one type of a metal selected from the group consisting of Zn, Al, and an alkali earth metal and at least one type of a water-soluble binder selected from the group consisting of gum arabic, gelatin, polymethacrylamide, and polyvinyl alcohol.

Abstract: A silicate phosphor comprising manganese as an activator, a trivalent element and a pentavalent element, wherein said trivalent element is at least one element selected from the group consisting of boron and indium, said pentavalent element is at least one element selected from the group consisting of arsenic, antimony and bismuth, the content of the trivalent element is from 1.times.10.sup.-4 to 2.times.10.sup.-2 gram-atom/mol, the content of the pentavalent element is not more than 3.times.10.sup.-3 gram-atom/mol, and the molar ratio of the trivalent element to the pentavalent element (trivalent element/pentavalent element) is at least 1.5.

Abstract: Blue, green, red and yellow emitting fluorescent compositions which emit blue, green, red and yellow light of high luminance under low-velocity electron excitation occurring under acceleration potential below 1KV, particularly below 100V can be obtained by mixing a conductive material having a particle diameter distribution wherein central value is within the range of 2.5 to 14.mu. and standard deviation is not more than 0.7, and specific blue, green, red and yellow emitting phosphors in a mixing weight ratio ranging from 1:99 to 1:4, respectively. The conductive material is selected from the group consisting of a conductive metal oxide, mixtures of more than one kind of conductive metal oxide, a conductive metal sulfide, mixtures of more than one kind of conductive metal sulfide and mixtures thereof. These blue, green, red and yellow emitting fluorescent compositions are used as a fluorescent screen of a low-velocity electron excited fluorescent display device.

Abstract: A semiconductor ceramic composition having positive temperature characteristics which comprises titanates of barium, lead and calcium which have 1 - 40 mole % of lead titanate and 1 - 22 mole % of calcium titanate and 38 - 98 mole % of barium titanate and 0.03 - 0.6 mole % of a semiconductor-forming component based on said titanates.