Abstract: A single crystal quartz thin film having a thickness of 5 nm to 50 .mu.m can be prepared by forming the thin film on a single crystal substrate by a sol-gel process and peeling the thin film from the substrate. The present invention can provide the single crystal quartz thin film at a low price without a large and complex apparatus.

Abstract: A single crystal of a nitride having a length of not less than 10 mm, a width of not less than 10 mm and a thickness of not less than 300 .mu.m, or having a length of not less than 20 mm and a diameter of not less than 10 .mu.m. In the production of the single crystal, either a mixed powder composed of a nitride powder and an oxide powder or an amorphous nitride powder is provided as a source material powder, the source material powder is heated in a nitrogen atmosphere or in a nitrogen atmosphere containing hydrogen and/or carbon at a temperature below the sublimation temperature or melting temperature of the nitride to decompose and vaporize the nitride powder, and the decomposed and vaporized component is subjected to crystal growth from the vapor phase on a substrate. The nitride single crystal is useful as a bulk material for heat sinks, electric and electronic components, such as semiconductors, optical components, and components of electric equipment and office automation equipment.

Abstract: A semiconductor device comprising single crystal films consisting of at least one III-V nitride selected from the group consisting of gallium nitride, aluminum nitride, boron nitride, indium nitride, and single-crystalline alloys of these nitrides, the single crystal films being provided on a single crystal substrate of aluminum nitride either directly or through a low-temperature growth buffer layer of at least one III-V nitride. This semiconductor device is useful as a short-wavelength light emitting device capable of conducting continuous oscillation or a diode which is operated at a high temperature. The AlN single crystal substrate is matched in lattice constant and coefficient of thermal expansion with the single crystal film of a III-V nitride and the single crystal films is grown with good crystallinity on the substrate.

Abstract: An oxide thin film having a quartz crystal structure formed on a substrate, the oxide thin film being composed of a single layer or a plurality of layers having a thickness of 5 nm to 50 .mu.m per layer, each of the layer comprising silicon dioxide, germanium dioxide, or a mixture thereof.

Abstract: A coating film which can sufficiently improve the wear resistance of a cutting tool or a wear-resistant tool and which reveals excellent qualities as a wear-resistant or protective film for an electric or electronic part or a sliding or machine part. Such a coating film is in the form of an ultra-thin film laminate comprising at least one nitride or carbonitride of at least one element selected from the group consisting of the elements in the groups IVa, Va and VIa in the periodic table and Al and B and having a cubic crystal structure and having mainly metallic bonding properties, and at least one compound having a crystal structure other than the cubic crystal structure at normal temperature and normal pressure and under equilibrium state and having mainly covalent bonding properties, the at least one nitride or carbonitride and the compound being alternately laminated in the form of layers, each layer of the compound having a thickness of 0.

Abstract: A binded carbon brush includes a brush main portion formed mainly of carbon, and an electric conductor formed by a material, such as a copper powder, having an electric resistivity lower than that of the brush main portion and extending along a main current direction of the brush. In the cross section of the brush perpendicular to the main current direction, the diameter or the vertical and horizontal sizes of the conductor is so set as to be smaller than both the vertical and horizontal sizes of the brush main portion.

Abstract: A coating film which can sufficiently improve the wear resistance of a cutting tool or a wear-resistant tool and which reveals excellent qualities as a wear-resistant or protective film for an electric or electronic part or a sliding or machine part. Such a coating film is in the form of an ultra-thin film laminate comprising at least one nitride or carbonitride of at least one element selected from the group consisting of the elements in the groups IVa, Va and VIa in the periodic table and Al and B and having a cubic crystal structure and having mainly metallic bonding properties, and at least one compound having a crystal structure other than the cubic crystal structure at normal temperature and normal pressure and under equilibrium state and having mainly covalent bonding properties, the at least one nitride or carbonitride and the compound being alternately laminated in the form of layers, each layer of the compound having a thickness of 0.

Abstract: A binded carbon brush includes a brush main portion formed mainly of carbon, and an electric conductor formed by a material, such as a copper powder, having an electric resistivity lower than that of the brush main portion and extending along a main current direction of the brush. In the cross section of the brush perpendicular to the main current direction, the diameter or the vertical and horizontal sizes of the conductor is so set as to be smaller than both the vertical and horizontal sizes of the brush main portion.

Abstract: A drive apparatus includes a commutator motor having a hollow rotation shaft with an internally threaded section provided therein and a flexible power transmission cable inserted through the hollow rotation shaft such that a spiral thread-like rib of the cable engages with the internally threaded section of the hollow rotation shaft, whereby a propulsive force is transmitted to the cable to allow a window glass to be moved in a reciprocating motion. A guide roller with an intermediate section of the cable wrapped therearound is rotatably supported on a guide base to allow the passage of the cable. A curved guide section is provided relative to the guide roller to define a curved cable passage channel in a manner to cover a wrapped cable portion. The guide roller is rotated by the commutator motor through the cable, while the intermediate portion of the cable is pressed onto the guide roller.

Abstract: A variable incident angle exposure apparatus wherein the incident angle of exposure light can be set as desired.