Abstract: Silica powder having a dielectric loss tangent of 0.004 or less, in which the number of silicon metal particles in 10 g of the silica powder is 30 or less. A method for producing silica powder, including a heating step of heating silica powder in the presence of chlorine. Silica powder having a low dielectric loss tangent and a low silicon metal content, and a method for producing the silica powder can be provided.

Abstract: Provided is an organic nanotube having a hydrophobized inner surface, formed by molecules including an asymmetric bipolar lipid molecule represented by the following General Formula (1) and a derivative thereof represented by the following General Formula (2), wherein the organic nanotube has a hydrophilized outer surface and a hydrophobized inner surface of a hollow cylinder and is formed by binary self-assembly, the organic nanotube encapsulates a hydrophobic guest in the hollow cylinder, has a function of refolding a denatured protein, and has a function of sustainably-releasing a hydrophobic drug according to the change in hydrophobicity of the inner surface of the tube or external stimulus, In Formulas (1) and (2), wherein the same symbols have the same meanings, G is a 1-glucopyranosyl group or 2-glucopyranosyl group, and n is an integer of 12 to 22.

Abstract: Provided is an organic nanotube having a hydrophobized inner surface, formed by molecules including an asymmetric bipolar lipid molecule represented by the following General Formula (1) and a derivative thereof represented by the following General Formula (2), wherein the organic nanotube has a hydrophilized outer surface and a hydrophobized inner surface of a hollow cylinder and is formed by binary self-assembly, the organic nanotube encapsulates a hydrophobic guest in the hollow cylinder, has a function of refolding a denatured protein, and has a function of sustainably-releasing a hydrophobic drug according to the change in hydrophobicity of the inner surface of the tube or external stimulus, In Formulas (1) and (2), wherein the same symbols have the same meanings, G is a 1-glucopyranosyl group or 2-glucopyranosyl group, and n is an integer of 12 to 22.

Abstract: There are provided glass-ceramics comprising, in mass %, 50-60% SiO2, 22-26% Al2O3 and 3-5% Li2O, having an average crystal grain diameter exceeding 100 nm, and having an average linear thermal expansion coefficient of 30×10?7/° C. or below within a temperature range of 0° C. to 50° C. These glass-ceramics are manufactured by a step of melting glass raw materials, a step of forming the molten glass, a step of annealing the formed glass, a first heat treating step for heat treating the annealed glass at a temperature of 650-750° C. for 0.1 hour to 200 hours, and a second heat treating step for heat treating the glass at a temperature of 800-1000° C. for 0.1 hour to 50 hours.

Abstract: There are provided glass-ceramics comprising, in mass %, 50-60% SiO2, 22-26% Al2O3 and 3-5% Li2O, having an average crystal grain diameter exceeding 100 nm, and having an average linear thermal expansion coefficient of 30×10?7/° C. or below within a temperature range of 0° C. to 50° C. These glass-ceramics are manufactured by a step of melting glass raw materials, a step of forming the molten glass, a step of annealing the formed glass, a first heat treating step for heat treating the annealed glass at a temperature of 650-750° C. for 0.1 hour to 200 hours, and a second heat treating step for heat treating the glass at a temperature of 800-1000° C. for 0.1 hour to 50 hours.

Abstract: There are provided low expansion transparent glass-ceramics obtained by heat treating a base glass produced at a relatively low melting temperature of 1530° C. or below. The glass-ceramics have an average linear thermal expansion coefficient within a range from +6×10?7/° C. to +35×10?7/° C., 80% transmittance wavelength (T80) of 700 nm or below, internal transmittance of 75% or over at light wavelength of 1550 nm, heat resisting temperature of 800° C. or over and Young's modulus of 90 GPa or over. The glass-ceramics comprise SiO2, Al2O3, MgO, CaO, BaO, ZnO, Li2O, TiO2 and ZrO2 and contain ?-quartz or ?-quartz solid solution as a predominant crystal phase. There are also provided optical waveguide elements and an arrayed waveguide grating (AWG) type planar lightwave circuit utilizing these glass-ceramics.

Abstract: There are provided low expansion transparent glass-ceramics obtained by heat treating a base glass produced at a relatively low melting temperature of 1530° C. or below. The glass-ceramics have an average linear thermal expansion coefficient within a range from +6×10?7/° C. to +35×10?7/° C., 80% transmittance wavelength (T80) of 700 nm or below internal transmittance of 75% or over at light wavelength of 1550 nm, heat resisting temperature of 800° C. or over and Young's modulus of 90 GPa or over. The glass-ceramics comprise SiO2, Al2O3, MgO, CaO, BaO, ZnO, Li2O, TiO2 and ZrO2 and contain ?-quartz or ?-quartz solid solution as a predominant crystal phase.

Abstract: There are provided low expansion transparent glass-ceramics obtained by heat treating a base glass produced at a relatively low melting temperature of 1530° C. or below. The glass-ceramics have an average linear thermal expansion coefficient within a range from +6×10−7/° C. to +35×10−7/° C., 80% transmittance wavelength (T80) of 700 nm or below internal transmittance of 75% or over at light wavelength of 1550 nm, heat resisting temperature of 800° C. or over and Young's modulus of 90 GPa or over. The glass-ceramics comprise SiO2, Al2O3, MgO, CaO, BaO, ZnO, Li2O, TiO2 and ZrO2 and contain &bgr;-quartz or &bgr;-quartz solid solution as a predominant crystal phase.

Abstract: A method for producing a crystallized glass member, the method includes: precisely polishing each surface of two or more crystallizable original glass components having an identical composition so that the polished surfaces to be brought into contact with each other have a flatness of &lgr; (633 nm) or less; heating the glass components to a first temperature in a glass transition region while the surfaces are brought into contact with each other so as to fuse the glass components; and heating an original glass member prepared by fusing the glass components at a second temperature which is higher than the first temperature in the glass transition region, so as to crystallize and bond the original glass member.

Abstract: An aluminosilicate transparent glass has corrosion resistance in the form of mass loss of 4.0 mg or below per 1cm2 of the surface of a specimen upon holding the specimen for five hours in sodium hydroxide solution having concentration of 300 mg(L under test pressure of 50 MPa at 250° C. The glass has a coefficient of thermal expansion within a range from 35×10−7/° C. to 50×10−7/° C. within a temperature range from 100° C to 300° C. The glass has also powdered glass mass loss rate of 0.1% or below in terms of water resistance, acid resistance and alkali resistance.

Abstract: There are provided low expansion transparent glass-ceramics obtained by heat treating a base glass produced at a relatively low melting temperature of 1530° C. or below. The glass-ceramics have an average linear thermal expansion coefficient within a range from +6×10−7/° C. to +35×10−7/° C., 80% transmittance wavelength (T80) of 700 nm or below, internal transmittance of 75% or over at light wavelength of 1550 nm, heat resisting temperature of 800° C. or over and Young's modulus of 90 GPa or over. The glass-ceramics comprise SiO2, Al2O3, MgO, CaO, BaO, ZnO, Li2O, TiO2 and ZrO2 and contain &bgr;-quartz or &bgr;-quartz solid solution as a predominant crystal phase. There are also provided optical waveguide elements and an arrayed waveguide grating (AWG) type planar lightwave circuit utilizing these glass-ceramics.