Provided are a method for manufacturing MgB.sub.2 superconductor by pressure molding a mixture of Mg powder or MgH.sub.2 powder and B powder and heat-treating the mixture, the method including (I) a step of adding a polycyclic aromatic hydrocarbon to the B powder, while heating the mixture to a temperature higher to or equal to the melting point of the polycyclic aromatic hydrocarbon at the time of this addition, and thereby covering the surface of the B powder with the polycyclic aromatic hydrocarbon; and (II) a step of mixing the B powder having the surface covered with the polycyclic aromatic hydrocarbon, with the Mg powder or the MgH.sub.2 powder, or a step of combining the B powder having the surface covered with the polycyclic aromatic hydrocarbon, with an Mg rod; and an MgB.sub.2 superconducting wire which has high critical current density (Jc) characteristics and less fluctuation in the critical current density (Jc).

A method of forming cemented tungsten tetraboride, by combining tungsten and boron in a molar ratio of from about 1:6 to about 1:12, respectively, and firing the combined tungsten and boron in a hexagonal boron nitride crucible at a temperature of from about 1600 C to about 2000 C, to form tungsten tetraboride, milling the tungsten tetraboride to a powder, adding a metal binder to the tungsten tetraboride powder to produce a metal-tungsten tetraboride mixture, compressing the metal-tungsten tetraboride mixture, and sintering the compressed metal-tungsten tetraboride mixture to form cemented tungsten tetraboride.

A method of forming cemented tungsten tetraboride, by combining tungsten and boron in a molar ratio of from about 1:6 to about 1:12, respectively, and firing the combined tungsten and boron in a hexagonal boron nitride crucible at a temperature of from about 1600 C to about 2000 C, to form tungsten tetraboride, milling the tungsten tetraboride to a powder, adding a metal binder to the tungsten tetraboride powder to produce a metal-tungsten tetraboride mixture, compressing the metal-tungsten tetraboride mixture, and sintering the compressed metal-tungsten tetraboride mixture to form cemented tungsten tetraboride.

Provided are an apparatus for manufacturing a compound powder, a method of manufacturing an iron-boron compound powder by using the apparatus, a boron alloy powder mixture, a method of manufacturing the boron alloy powder mixture, a combined powder structure, a method of manufacturing the combined powder structure, a steel pipe, and a method of manufacturing the steel pipe The method of manufacturing the boron alloy powder mixture includes: preparing a mixed powder including a boron iron alloy powder and a target powder; heat-treating the mixed powder to boronize at least a portion of the target powder and de-boronize at least a portion of the boron iron alloy powder, thereby de-boronizing the boron iron alloy powder to reduce the melting point of the boron iron alloy powder.

A solar radiation shielding laminated structure, having high visible light transmission property and solar radiation shielding property, low haze value, and high environmental stability with inexpensive production cost, using solar radiation shielding fine particles having high visible light transmission property and excellent solar shielding property and weather resistance, and provides a solar radiation shielding laminated structure in which an interlayer is sandwiched between two laminated sheets; the interlayer having, as an intermediate film, one or more kinds selected from a resin sheet containing solar radiation shielding fine particles and a resin film containing solar radiation shielding fine particles, the laminated sheets being selected from a sheet-glass not containing solar radiation shielding fine particles and a resin board not containing solar radiation shielding fine particles; wherein the solar radiation shielding fine particles are solar radiation shielding fine particles containing calcium lanthanum boride fine particles represented by general formula CaxLa1-xBm.

Provided is a method for manufacturing a base material powder having a carbon nanocoating layer, the method including adding a polycyclic aromatic hydrocarbon to a base material powder, heating the mixture to a temperature that is higher than or equal to the boiling point of the polycyclic aromatic hydrocarbon and is lower than or equal to the relevant boiling point temperature +300° C., and that is higher than or equal to the thermal decomposition temperature of the polycyclic aromatic hydrocarbon, and thereby coating the surface of the base material powder with a layer of carbon having a thickness of 0.1 nm to 10 nm. According to the method, when a source of carbon that covers a base material powder is appropriately selected, the base material powder having the carbon nanocoating layer can be provided, which does not have a possibility of causing inconveniences in the applications of a final manufactured product of the base material powder and exhibits satisfactory productivity of the base material powder, and from which a modified final manufactured product is obtained.

Provided is a method for manufacturing a base material powder having a carbon nanocoating layer, the method including adding a polycyclic aromatic hydrocarbon to a base material powder, heating the mixture to a temperature that is higher than or equal to the boiling point of the polycyclic aromatic hydrocarbon and is lower than or equal to the relevant boiling point temperature +300° C., and that is higher than or equal to the thermal decomposition temperature of the polycyclic aromatic hydrocarbon, and thereby coating the surface of the base material powder with a layer of carbon having a thickness of 0.1 nm to 10 nm. According to the method, when a source of carbon that covers a base material powder is appropriately selected, the base material powder having the carbon nanocoating layer can be provided, which does not have a possibility of causing inconveniences in the applications of a final manufactured product of the base material powder and exhibits satisfactory productivity of the base material powder, and from which a modified final manufactured product is obtained.

A method of reducing color in an alkanolamine, the method comprising: contacting the alkanolamine with an amount of an aqueous solution effective to provide 5 to 1000 parts per million by weight of an alkali metal borohydride, based on parts by weight of the alkanolamine; and 0.5 to 10,000 parts per million by weight of an alkali metal hydroxide, based on parts by weight of the alkanolamine; preferably wherein the color-reduced alkanolamine is not distilled after the contacting.

A method of reducing color in an alkanolamine, the method comprising: contacting the alkanolamine with an amount of an aqueous solution effective to provide 5 to 1000 parts per million by weight of an alkali metal borohydride, based on parts by weight of the alkanolamine; and 0.5 to 10,000 parts per million by weight of an alkali metal hydroxide, based on parts by weight of the alkanolamine; preferably wherein the color-reduced alkanolamine is not distilled after the contacting.

A method of reducing color in an alkanolamine, the method comprising: contacting the alkanolamine with an amount of an aqueous solution effective to provide 5 to 1000 parts per million by weight of an alkali metal borohydride, based on parts by weight of the alkanolamine; and 0.5 to 10,000 parts per million by weight of an alkali metal hydroxide, based on parts by weight of the alkanolamine; preferably wherein the color-reduced alkanolamine is not distilled after the contacting.