Abstract: A color wheel including a disk-shaped substrate made of a light-transmittable medium and a plurality of filters arranged on the substrate is fabricated. Each filter is capable of selectively transmitting rays of light having a desired wavelength. The method of fabricating the color wheel including the steps of forming at least one of a plurality of adjoining selective color-transmittable films as the filters each at a predetermined area on a front side of the disk-shaped substrate, and utilizing, as a mask for exposure from a back side of the disk-shaped substrate, a portion containing at least one of two borders with which each one of the plurality of adjoining selective color-transmittable films is defined.

Abstract: A color wheel including a disk-shaped substrate made of a light-transmittable medium and a plurality of filters arranged on the substrate is fabricated. Each filter is capable of selectively transmitting rays of light having a desired wavelength. The method of fabricating the color wheel including the steps of forming at least one of a plurality of adjoining selective color-transmittable films as the filters each at a predetermined area on a front side of the disk-shaped substrate, and utilizing, as a mask for exposure from a back side of the disk-shaped substrate, a portion containing at least one of two borders with which each one of the plurality of adjoining selective color-transmittable films is defined.

Abstract: Methods for producing ruthenium perovskite represented by a chemical formula LaRuO3, wherein La is lanthanum to which twelve oxygen ions are coordinated, Ru is ruthenium to which six oxygen ions are coordinated, and O is oxygen, which comprises reacting an aqueous mixed metal ion solution containing metal ions of La and Ru with a precipitate-forming liquid in a reaction container to co-precipitate hydroxides of La and Ru, and subjecting the precipitate to a heat treatment. Alternatively, the co-precipitated mass is deposited on a suitable carrier and subsequently heated to form supported LaRuO3. The co-precipitated La and Ru hydroxides can also be directly formed on a carrier by precipitation from a homogenous solution containing La, Ru and urea. This provides a uniform dispersion of co-precipitated hydroxides on a carrier, subsequent heating of which results in formation of supported LaRuO3. The materials thus obtained are to be used as efficient catalysts for certain reactions of environmental importance.

Abstract: Methods for producing ruthenium perovskite represented by a chemical formula LaRuO3, wherein La is lanthanum to which twelve oxygen ions are coordinated, Ru is ruthenium to which six oxygen ions are coordinated, and O is oxygen, which comprises reacting an aqueous mixed metal ion solution containing metal ions of La and Ru with a precipitate-forming liquid in a reaction container to co-precipitate hydroxides of La and Ru, and subjecting the precipitate to a heat treatment. Alternatively, the co-precipitated mass is deposited on a suitable carrier and subsequently heated to form supported LaRuO3. The co-precipitated La and Ru hydroxides can also be directly formed on a carrier by precipitation from a homogenous solution containing La, Ru and urea. This provides a uniform dispersion of co-precipitated hydroxides on a carrier, subsequent heating of which results in formation of supported LaRuO3. The materials thus obtained are to be used as efficient catalysts for certain reactions of environmental importance.

Abstract: A method for rapidly imparting hydrophobicity to an oxide solid surface, which comprises exerting a mechanical stimulation to a desired region of a hydrophilicity-imparted oxide solid surface, to change said region to be hydrophobic.

Abstract: A tetragonal system tunnel-structured compound having the formula:A.sub.x [Ga.sub.8 M.sub.y Ga.sub.(8+x)-y Ti.sub.16-x O.sub.56 ](I)wherein A is at least one alkali metal selected from the group consisting of K, Rb and Cs, or a solid solution of such alkali metal with lithium, sodium or barium, M is at least one trivalent metal selected from the group consisting of Al, Fe and Cr, x is a number of from 0.1 to 2.0, and y is a number of from 0 to 10.

Abstract: A process for producing potassium hexatitanate fibers having a tunnel structure, which comprises mixing a titanium component represented by the general formula (Ti, M)O.sub.2 where M is metal impurities with a potassium component selected from the group consisting of potassium oxide, potassium compounds capable of forming potassium oxide when heated and a mixture thereof, to obtain a mixture represented by the general formula K.sub.2 O.n(Ti, N)O.sub.2 where n is from 1.5 to 2.5 and M is as defined above; heating the mixture to obtain a melt; forming from the melt a fibrous material having a layered crystalline structure corresponding to potassium dititanate (K.sub.2 O.2TiO.sub.2); leaching a part of K.sub.2 O from the fibrous material; and heating the fibrous material at a temperature of at least 800.degree. C. and lower than the melting point of the fibrous material.