Abstract: The objective of the present invention is to provide a method for producing a calcite single crystal which is appropriately fine in a large scale with no difficulty. The method for producing a calcite single crystal according to the present invention is characterized in comprising the steps of mixing raw material calcium carbonate with an ammonium nitrate aqueous solution to obtain a raw material mixed liquid, wherein pH of the ammonium nitrate aqueous solution is not less than 7.0 and not more than 8.0, a concentration of the ammonium nitrate aqueous solution is not less than 2 M, and a concentration of calcium carbonate in the raw material mixed liquid is not less than 4 g/L and not more than 16 g/L; heating the raw material mixed liquid at not less than 125° C.; and then gradually cooling the raw material mixed liquid.

Abstract: An appropriate catalyst is found for synthesis of an unsaturated carboxylic acid and/or a derivative thereof using as a raw material compound a hydroxycarboxylic acid and/or a derivative thereof that can easily be synthesized from a polysaccharide such as biomass-derived cellulose, and an efficient method for synthesizing the unsaturated carboxylic acid and/or the derivative thereof is provided. This method is a method for synthesizing an unsaturated carboxylic acid and/or a derivative thereof, wherein an apatite compound is used as a catalyst to synthesize the unsaturated carboxylic acid and/or the derivative thereof from a biomass-derived hydroxycarboxylic acid and/or a derivative thereof by a dehydration reaction.

Abstract: The present invention is intended to provide a catalyst which is for synthesizing butanol from ethanol at a high selectivity and which comprises strontium phosphate apatite having the Sr/P atomic ratio of 1.5-2.0, and the synthesis method.

Abstract: According to the present invention, a fluorescent powder composed mainly of an acicular or fibrous zinc oxide single crystal with an aspect ratio of 5 or higher is produced by the following steps: a step of producing a raw material solution selected from the group consisting of a raw material solution (A) that is an alkali solution containing zing ions, a raw material solution (B) that is a solution containing zinc ions and ions of dopant element, and a mixed solution of the raw material solution (A) and the raw material solution (B); and a hydrothermal reaction step wherein a hydrothermal reaction of the mixed solution is carried out in a hermetically sealed vessel at a subcritical or supercritical temperature and at a subcritical or supercritical pressure. A zinc oxide single crystal powder can be produced at low cost without the need for a pulverization step or a similar step and high-density orientation can be realized by such crystal powder.

Abstract: The present invention is intended to provide a catalyst which is for synthesizing butanol from ethanol at a high selectivity and which comprises strontium phosphate apatite having the Sr/P atomic ratio of 1.5-2.0, and the synthesis method.

Abstract: This invention provides a fine particle composite comprising fine powder of a sulfide or sulfide complex comprising a given element. The fine particle composite is obtained by a method for producing a fine particle composite comprising fine powder of a sulfide or sulfide complex comprising at least one element selected from the group consisting of molybdenum (Mo), rhodium (Rh), ruthenium (Ru), and rhenium (Re). Such method comprises steps of: preparing a solvent mixture from at least one compound containing an element selected from among molybdenum (Mo), rhodium (Rh), ruthenium (Ru), rhenium (Re), and sulfur (S); and subjecting the solvent mixture to a hydrothermal or solvothermal reaction. The resulting fine particle composite comprises fine particles of a sulfide or sulfide complex comprising at least one element selected from the group consisting of molybdenum (Mo), rhodium (Rh), ruthenium (Ru), and rhenium (Re).

Abstract: This invention provides a fine particle composite comprising fine particles of a sulfide or sulfide complex comprising at least one element selected from the group consisting of molybdenum (Mo), rhodium (Rh), ruthenium (Ru), and rhenium (Re) and conductive fine particles via a step of preparing a solvent mixture from a compound containing conductive carbon powder, at least one compound containing an element selected from among molybdenum (Mo), rhodium (Rh), ruthenium (R), and rhenium (Re), and sulfur (S) and a step of conducting a hydrothermal or solvothermal reaction at a pressure and temperature that convert the solvent mixture into a supercritical or subcritical water or solvent.

Abstract: According to the present invention, a fluorescent powder composed mainly of an acicular or fibrous zinc oxide single crystal with an aspect ratio of 5 or higher is produced by the following steps: a step of producing a raw material solution selected from the group consisting of a raw material solution (A) that is an alkali solution containing zing ions, a raw material solution (B) that is a solution containing zinc ions and ions of dopant element, and a mixed solution of the raw material solution (A) and the raw material solution (B); and a hydrothermal reaction step wherein a hydrothermal reaction of the mixed solution is carried out in a hermetically sealed vessel at a subcritical or supercritical temperature and at a subcritical or supercritical pressure. A zinc oxide single crystal powder can be produced at low cost without the need for a pulverization step or a similar step and high-density orientation can be realized by such crystal powder.

Abstract: This invention provides a method for producing calcite-type calcium carbonate single crystal available for optical elements, which can be carried out under relatively low temperature and low pressure conditions. The crystal growth process which comprises; a first step of filling a sealed pressure container of an autoclave with solvent and calcium carbonate as a raw material for growth, a second step of dissolving the starting rate in the solvent under predetermined conditions of pressure and temperature, a third step of crystallizing the calcium carbonate on a seed crystal suspended in the upper portion of the pressure container, on account of the difference of solubility caused by temperature gradient in the container; the method is characterized by that the aqueous solution of ammonium salt of mono-carboxylic acid is used as the solvent.