The present invention relates to a glass including, represented by mole percent based on oxides: from 52% to 80% of SiO.sub.2; from 5% to 30% of B.sub.2O.sub.3; from 2% to 30% of Al.sub.2O.sub.3; from 0.1% to 11% of P.sub.2O.sub.5; and from 0.0001% to 5% of Na.sub.2O, in which the glass has an average thermal expansion coefficient α at from 50° C. to 350° C. of from 5×10.sup.−7/° C. or more and 33×10.sup.−7/° C. or less.

A metal boride aerogel includes a three-dimensional aerogel structure comprising metal boride particles having an average diameter of less than one micron. A method is disclosed for forming a metal boride aerogel including dispersing boron nanoparticles in a solution of a metal salt, forming a boron-loaded metal oxide precursor gel using the dispersed boron nanoparticles in the solution of the metal salt, drying the boron-loaded metal oxide precursor gel to form a boron-loaded metal oxide precursor aerogel, and heating the boron-loaded metal oxide precursor aerogel to form a metal boride aerogel. The metal boride aerogel is essentially free of metal oxide.

Provided is a boron nitride sintered body including boron nitride particles and pores, in which a compressive elastic modulus is 1 GPa or more. Provided is a method for manufacturing a boron nitride sintered body, the method including: a nitriding step of firing a boron carbide powder in a nitrogen atmosphere to obtain a fired product containing boron carbonitride; and a sintering step of molding and heating a blend containing the fired product and a sintering aid to obtain the boron nitride sintered body including boron nitride particles and pores, in which the sintering aid contains a boron compound and a calcium compound, and the blend contains 1 to 20 parts by mass of the boron compound and the calcium compound in total with respect to 100 parts by mass of the fired product.

A process for making a thermal insulation material based on carbon and which includes carbon fibers, suitable for use at temperatures above 1,500° C. The process includes providing carbon fibers with embedded carbon black particles; cutting or milling said carbon fibers to obtain short carbon filaments; preparing a slurry by introducing the short carbon filaments in a liquid phase that includes a binder capable of forming a carbon residue upon pyrolysis under non-oxidizing conditions; casting the slurry into a mold capable of separating the slurry into a wet green body and a liquid phase; and drying and heat treating the wet green body to obtain a thermal insulation material.

Provided is a method for manufacturing a composite body, the method including: a nitriding step of firing a boron carbide powder in a nitrogen atmosphere to obtain a fired product containing boron carbonitride; a sintering step of molding and heating a blend containing the fired product and a sintering aid to obtain a boron nitride sintered body including boron nitride particles and pores; and an impregnating step of impregnating the boron nitride sintered body with a resin composition, the composite body having the boron nitride sintered body and a resin filled in at least some of the pores of the boron nitride sintered body.

Provided is a sintered body that has high heat dissipation and from which light can be emitted when excited by an excitation light source, a light emitting device, a wavelength conversion member, and a method for manufacturing the sintered body.

The sintered body includes aluminum nitride and europium, has a thermal diffusivity of 27.0 mm.sup.2/s or greater as measured by a laser flash method at 25° C., and emits green light when excited by an excitation light source.

Provided is a boron nitride sintered body including: a plurality of coarse particles each having a length of 20 μm or more; and fine particles smaller than the plurality of coarse particles, in which, when viewed in a cross-section, the plurality of coarse particles intersect with each other. Provided is a method for manufacturing a boron nitride sintered body, the method including: a raw material preparation step of firing a mixture containing boron carbonitride and a boron compound in a nitrogen atmosphere to obtain lump boron nitride having an average particle diameter of 10 to 200 μm; and a sintering step of molding and heating a blend containing the lump boron nitride and a sintering aid to obtain a boron nitride sintered body including coarse particles each having a length of 20 μm or more in a cross-section and fine particles smaller than the coarse particles.

The present disclosure relates to a magnesium-based raw material and a preparation method thereof. According to the technical solution, 40-60 wt % fused magnesia particles, 30-40 wt % fine monoclinic zirconia powder, 5-20 wt % fine zirconium oxychloride powder, 0.5-1.5 wt % calcium hydroxide nanopowder, 0.2-0.5 wt % calcium hydroxide nanopowder, and 0.1-0.3 wt % maleic acid are stirred for 15 min to mix well in a high-speed mixing mill at a constant temperature of 25° C. to obtain a mixed powder; and the mixed powder is mixed through a ball mill at a constant temperature of 25° C. for 3 min, roasted in a high temperature furnace at 250-400° C. for 0.5-3 h, and finally cooled to room temperature.

The heat resistant structure of the flying body is provided with a tip part and a body part. The tip part is arranged in a front end of the flying body with respect to a direction of travel of the flying body. The body part is arranged in a back direction from the tip part with respect to the direction of travel of the flying body. The tip part is provided with a surface member, a base part, and an insulation member. The surface member is arranged on an outer surface of the tip part and has a melting point higher than a desired temperature. The base part couples the surface member to the body part. The insulation member is arranged between the surface member and the base part., and thermally insulates the base part from the surface member.

Disclosed is a cordierite sintered body comprising from 90 to 98% by volume of a cordierite crystal phase as measured using x ray diffraction, SEM and image processing methods wherein the cordierite sintered body has at least one surface comprising pores having a diameter of from 0.1 to 5 um as measured using SEM and image processing methods. The cordierite sintered body has a Young's modulus of about 125 GPa or greater, and volumetric porosity of less than about 4%. Methods of making the cordierite sintered body are also disclosed.