Abstract: A method of producing boron trichloride, which includes: a metal chlorination step of bringing a gas containing chlorine gas into contact with raw boron carbide as boron carbide including, as an impurity, a metal other than boron, and allowing the metal to react with the chlorine gas in the gas containing the chlorine gas, to form a metal chloride and to obtain boron carbide containing the metal chloride; a removal step of removing the metal chloride from the boron carbide containing the metal chloride, obtained in the metal chlorination step; and a generation step of bringing a gas containing chlorine gas into contact with the boron carbide from which the metal chloride has been removed in the removal step, and allowing the boron carbide and the chlorine gas in the gas containing the chlorine gas to react with each other to generate boron trichloride.

Abstract: Provided is an octafluorocyclobutane purification method capable of removing contained fluorocarbons to yield a highly pure octafluorocyclobutane. The octafluorocyclobutane purification method includes a decomposition step of mixing a crude octafluorocyclobutane containing octafluorocyclobutane and fluorocarbons as impurities with oxygen gas or air to give a mixed gas containing the oxygen gas or air at a concentration of 1% by volume or more and 90% by volume or less and bringing the mixed gas into contact with an impurity decomposing agent containing alumina and an alkaline earth metal compound and to decompose fluorocarbons, at a temperature of 100° C. or more and 500° C. or less to decompose the fluorocarbons and a concentration step of removing, from the mixed gas in which the fluorocarbons have been decomposed in the decomposition step, the gas containing oxygen gas or air (except octafluorocyclobutane) to increase the concentration of the octafluorocyclobutane.

Abstract: Provided is a sulfur dioxide mixture that hardly corrodes metals. A sulfur dioxide mixture contains sulfur dioxide and water. The sulfur dioxide mixture is filled in a filling container in such a manner that a gas phase and a liquid phase exist, and the moisture concentration of the gas phase is from 0.005 mole ppm to less than 5,000 mole ppm.

Abstract: A nitrous oxide purification method includes a step of performing gas separation by introducing a mixed gas containing nitrous oxide into a gas separation membrane including a polymer material to cause nitrous oxide to selectively permeate the gas separation membrane.

Abstract: There is provided a method of producing boron trichloride, in which boron trichloride with high purity can be produced in simple production steps, and blockage of a production line is inhibited.

Abstract: There is provided a method of producing boron trichloride, in which damage to a reaction container is inhibited. The method of producing boron trichloride includes performing reaction between chlorine gas in a gas containing the chlorine gas and particulate boron carbide (4) in a state in which the boron carbide (4) flows in the gas containing the chlorine gas.

Abstract: A method of cleaning a SiC monocrystal growth furnace provided with an in-furnace substrate composed of a 3C-SiC polycrystal having at least a surface in which an intensity ratio of a (111) plane with respect to other crystal planes is at least 85% but not more than 100% according to powder XRD analysis, the method including flowing a mixed gas of fluorine gas and at least one of an inert gas and air in a non-plasma state through the inside of the SiC monocrystal growth furnace, thereby selectively removing a SiC deposit deposited inside the SiC monocrystal growth furnace, wherein the mixed gas comprises at least 1 vol % but not more than 20 vol % of fluorine gas, and at least 80 vol % but not more than 99 vol % of an inert gas, and a temperature inside the SiC monocrystal growth furnace is from 200° C. to 500° C.

Abstract: Provided is a method for producing boron trichloride capable of efficiently producing boron trichloride by suppressing the generation of byproducts resulting from water by sufficiently removing water from a reaction system. The method for producing boron trichloride includes: a dehydration step of bringing a chlorine-containing gas which contains chlorine gas and has a water content of 1 ppm by volume or less into contact with boron carbide at a temperature lower than a generation starting temperature at which the generation of the boron trichloride starts by the reaction between the boron carbide and the chlorine gas, and allowing water in the boron carbide to react with the chlorine gas in the chlorine-containing gas to remove the water contained in the boron carbide; and a generation step of allowing the boron carbide dehydrated in the dehydration step to react with the chlorine gas to generate boron trichloride.

Abstract: A method of cleaning a SiC monocrystal growth furnace provided with an in-furnace substrate composed of a 3C-SiC polycrystal having at least a surface in which an intensity ratio of a (111) plane with respect to other crystal planes is at least 85% but not more than 100% according to powder XRD analysis, the method including flowing a mixed gas of fluorine gas and at least one of an inert gas and air in a non-plasma state through the inside of the SiC monocrystal growth furnace, thereby selectively removing a SiC deposit deposited inside the SiC monocrystal growth furnace, wherein the mixed gas comprises at least 1 vol % but not more than 20 vol % of fluorine gas, and at least 80 vol % but not more than 99 vol % of an inert gas, and a temperature inside the SiC monocrystal growth furnace is from 200° C. to 500° C.

Abstract: The image correction method according to an embodiment of the present invention includes the steps of: (a) generating an absorption correction map by replacing a CT value of each pixel of a CT image with a corresponding linear absorption coefficient and replacing the linear absorption coefficient in a bone region with the linear absorption coefficient of water or a soft biological tissue; and (b) generating a corrected image by multiplying a value of each pixel of a nuclear medical image obtained with respect to substantially the same tomographic plane as a plane in which the CT image has been obtained by a corresponding pixel of the absorption correction map.

Abstract: The image correction method according to an embodiment of the present invention includes the steps of: (a) generating an absorption correction map by replacing a CT value of each pixel of a CT image with a corresponding linear absorption coefficient and replacing the linear absorption coefficient in a bone region with the linear absorption coefficient of water or a soft biological tissue; and (b) generating a corrected image by multiplying a value of each pixel of a nuclear medical image obtained with respect to substantially the same tomographic plane as a plane in which the CT image has been obtained by a corresponding pixel of the absorption correction map.