To provide a glass plate for a window material and a window comprising the glass plate, which are less likely to be a barrier to radio transmitting/receiving in use of a radio-utilizing apparatus, and a radio communication apparatus comprising the glass plate. A glass plate having a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, a window comprising the glass plate, and a radio communication apparatus comprising the glass plate.

A glass material with high refractive index and radiation resistance, the method for preparing the same, and applications thereof, wherein the glass material, by mass percentage, includes 20-40% SiO.sub.2, 0-10% Al.sub.2O.sub.3, 0-5% CaO, 5-20% BaO, 40-50% PbO, 1-5% CeO.sub.2, 0-5% La.sub.2O.sub.3, 0-2% Nb.sub.2O.sub.5, 0-2% Ta.sub.2O.sub.5, 0-1% Bi.sub.2O.sub.3, and a content of 0-1% of an oxide selected from Na.sub.2O, K.sub.2O, Rb.sub.2O, and Cs.sub.2O. The glass material has a refractive index1.80, a glass transition temperature560 C., a yield point temperature650 C., and good thermal resistance. Its coefficient of thermal expansion is (85-90)10.sup.7/ C., indicating good thermal processability, suitable for forming large-sized devices. After irradiation with a 4700Gy dose of X-rays, a transmittance reduction is 2%, making it suitable for creating radiation-resistant optical components such as optical glass and fiber optic panels.

A glass material with high refractive index and radiation resistance, the method for preparing the same, and applications thereof, wherein the glass material, by mass percentage, includes 20-40% SiO.sub.2, 0-10% Al.sub.2O.sub.3, 0-5% CaO, 5-20% BaO, 40-50% PbO, 1-5% CeO.sub.2, 0-5% La.sub.2O.sub.3, 0-2% Nb.sub.2O.sub.5, 0-2% Ta.sub.2O.sub.5, 0-1% Bi.sub.2O.sub.3, and a content of 0-1% of an oxide selected from Na.sub.2O, K.sub.2O, Rb.sub.2O, and Cs.sub.2O. The glass material has a refractive index1.80, a glass transition temperature560 C., a yield point temperature650 C., and good thermal resistance. Its coefficient of thermal expansion is (85-90)10.sup.7/ C., indicating good thermal processability, suitable for forming large-sized devices. After irradiation with a 4700Gy dose of X-rays, a transmittance reduction is 2%, making it suitable for creating radiation-resistant optical components such as optical glass and fiber optic panels.

A glass production method for obtaining a glass from a glass-containing raw material, the method including: obtaining a first melt by melting the glass-containing raw material; precipitating a metal phase by subjecting the first melt to a reduction treatment; obtaining a second melt by separating at least a part of the metal phase from the first melt; and subjecting the second melt to an oxidation treatment.

A glass production method for obtaining a glass from a glass-containing raw material, the method including: obtaining a first melt by melting the glass-containing raw material; precipitating a metal phase by subjecting the first melt to a reduction treatment; obtaining a second melt by separating at least a part of the metal phase from the first melt; and subjecting the second melt to an oxidation treatment.

To provide a glass plate for a window material and a window comprising the glass plate, which are less likely to be a barrier to radio transmitting/receiving in use of a radio-utilizing apparatus, and a radio communication apparatus comprising the glass plate.

A glass plate having a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, a window comprising the glass plate, and a radio communication apparatus comprising the glass plate.

Provided is a dental bulk block made from a glass-ceramic material having a crystalline phase embedded in an amorphous glass matrix. The crystalline phase includes eucryptite and at least one lithium silicate-based crystalline phase selected from the group consisting of lithium metasilicate and lithium disilicate. The dental bulk block is a functionally graded material having a crystalline size gradient with respect to a depth thereof and having no interface at a point of change in main crystalline size gradient value. The bulk block that is heat-treated at 820 C. for 40 minutes exhibits a characteristic peak of a spodumene crystalline phase in an X-ray diffraction analysis result graph unlike the bulk block that is heat-treated at 820 C. for 2 minutes.