Abstract: A premixing apparatus includes a mixing unit, an air supply adjusting unit, and a gas switching unit. The mixing unit draws a fuel gas in the mixing unit by supplied air to mix the fuel gas and the supplied air with each other. The air supply adjusting unit applies a load on the supplied air flowing toward the mixing unit and switches the load. The gas switching unit switches a gas amount of the fuel gas to be supplied to the mixing unit.

Abstract: A premixing apparatus includes a mixing unit, an air supply adjusting unit, and a gas switching unit. The mixing unit draws a fuel gas in the mixing unit by supplied air to mix the fuel gas and the supplied air with each other. The air supply adjusting unit applies a load on the supplied air flowing toward the mixing unit and switches the load. The gas switching unit switches a gas amount of the fuel gas to be supplied to the mixing unit.

Abstract: A premixing apparatus includes a mixing unit, an air supply adjusting unit, and a gas switching unit. The mixing unit draws a fuel gas in the mixing unit by supplied air to mix the fuel gas and the supplied air with each other. The air supply adjusting unit applies a load on the supplied air flowing toward the mixing unit and switches the load. The gas switching unit switches a gas amount of the fuel gas to be supplied to the mixing unit.

Abstract: A premixing apparatus includes a mixing unit, an air supply adjusting unit, and a gas switching unit. The mixing unit draws a fuel gas in the mixing unit by supplied air to mix the fuel gas and the supplied air with each other. The air supply adjusting unit applies a load on the supplied air flowing toward the mixing unit and switches the load. The gas switching unit switches a gas amount of the fuel gas to be supplied to the mixing unit.

Abstract: A premixing apparatus includes a mixing unit, an air supply adjusting unit, and a gas switching unit. The mixing unit draws a fuel gas in the mixing unit by supplied air to mix the fuel gas and the supplied air with each other. The air supply adjusting unit applies a load on the supplied air flowing toward the mixing unit and switches the load. The gas switching unit switches a gas amount of the fuel gas to be supplied to the mixing unit.

Abstract: An aromatic polycarbonate copolymer is useful for a substrate of an optical disk and is composed of 1 to 99 mole percent of the unit of 2,2-bis(4-hydroxy-3-tertiary-butyl-phenyl)propane, 99 to 1 mole percent of the unit of a comonomer selected from the group consisting of(1) 2,2-bis(4-hydroxyphenyl)propane,(2) 4,4'-dihydroxy-2,2,2-triphenylethane,(3) 2,2-bis(4-hydroxy-3-methylphenyl)-propane,(4) 1,1'-bis(4-hydroxyphenyl)-p-diisopropylbenzene,(5) 1,1'-bis(4-hydroxyphenyl)-m-diisopropyl-benzene,(6) 2,2-bis(4-hydroxyphenyl)butane,(7) 2,2-bis(4-hydroxyphenyl)-4-methylpentane,(8) 2,2-bis(4-hydroxyphenyl)octane,(9) 1,1-bis(4-hydroxyphenyl)cyclohexane and(10) 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propaneand a carbonate group located between the two units.

Abstract: A flavone glycoside having the formula is isolated from the natural source and is found to be effective to amelioration of the hemolinetic disturbance.

Abstract: Novel cellulose ester derivatives having good solubility which are useful for coating agent, thickening agent, protective colloid, etc.; and a method for the preparation of said cellulose ester derivatives wherein cellulose is reacted with a specific lactone such as glycolide, lactide or .epsilon.-caprolactone in a solvent and in the presence of a catalyst for esterification.