The present invention relates to a method for searching for a structural gene of glass, including the following steps: determining atomic species for structure search according to the glass system; performing structural screening on the basis of the first principle to screen out compounds that can be formed by the interaction between each of the atoms; comparing the formation energy and the phonon spectrum of each compound to obtain stable compounds; and constructing a metastable composition diagram of a glass system according to the stable compounds, in metastable composition diagram, a micro-structural unit of a glassy compound near a target glass composition point is the structural gene of glass in the metastable glass composition diagram.

Glass compositions include phosphorus oxide (P.sub.2O.sub.5), niobia (Nb.sub.2O.sub.5), barium oxide (BaO) and potassium oxide (K.sub.2O) as essential components and may optionally include titania (TiO.sub.2), calcium oxide (CaO), sodium oxide (Na.sub.2O), lithium oxide (Li.sub.2O), bismuth oxide (Bi.sub.2O.sub.3), strontium oxide (SrO), tungsten oxide (WO.sub.3) and other components. The glasses may be characterized by high refractive index at 587.56 nm at comparably low density at room temperature.

Glass compositions include phosphorus oxide (P.sub.2O.sub.5), niobia (Nb.sub.2O.sub.5), barium oxide (BaO) and potassium oxide (K.sub.2O) as essential components and may optionally include titania (TiO.sub.2), calcium oxide (CaO), sodium oxide (Na.sub.2O), lithium oxide (Li.sub.2O), bismuth oxide (Bi.sub.2O.sub.3), strontium oxide (SrO), tungsten oxide (WO.sub.3) and other components. The glasses may be characterized by high refractive index at 587.56 nm at comparably low density at room temperature.

Provided is a novel positive electrode active material for a sodium-ion secondary cell having a good discharge capacity. A positive electrode active material for a sodium-ion secondary cell, the positive electrode active material containing, in terms of % by mole of oxide, 8 to 55% Na.sub.2O, 10 to 70% NiO, 0 to 60% CrO+FeO+MnO+CoO, and 15 to 70% P.sub.2O.sub.5+SiO.sub.2+B.sub.2O.sub.3 and containing an amorphous phase.

Provided is a novel positive electrode active material for a sodium-ion secondary cell having a good discharge capacity. A positive electrode active material for a sodium-ion secondary cell, the positive electrode active material containing, in terms of % by mole of oxide, 8 to 55% Na.sub.2O, 10 to 70% NiO, 0 to 60% CrO+FeO+MnO+CoO, and 15 to 70% P.sub.2O.sub.5+SiO.sub.2+B.sub.2O.sub.3 and containing an amorphous phase.

Disclosed herein are glasses that present several advantages over traditional glass compositions used in optical applications. The glasses disclosed herein have a low devitrification tendency and can be processed by melt quenching and formed into macroscopic components. The glasses have high glass thermal stability indices and are chemically durable. The glasses disclosed herein are transparent when heat treated in air or oxygen and have high refractive indices and low density, as well, making them suitable for optical applications.

Disclosed herein are glasses that present several advantages over traditional glass compositions used in optical applications. The glasses disclosed herein have a low devitrification tendency and can be processed by melt quenching and formed into macroscopic components. The glasses have high glass thermal stability indices and are chemically durable. The glasses disclosed herein are transparent when heat treated in air or oxygen and have high refractive indices and low density, as well, making them suitable for optical applications.

A user device for monitoring a physical condition of a user, such as a heart rate or blood oxygen level, includes an erbium doped glass component and a light source. The light source is configured to generate light equal to an excitation frequency of the erbium doped glass. The erbium doped glass component is configured to generate, through photoluminescence, one or more peaks of higher intensity light corresponding to a wavelength which can be used to monitor a physical condition of a user. The amplified light is sent to the user and received back at a photodetector, which can then algorithmically determine a physical condition of a user.

A user device for monitoring a physical condition of a user, such as a heart rate or blood oxygen level, includes an erbium doped glass component and a light source. The light source is configured to generate light equal to an excitation frequency of the erbium doped glass. The erbium doped glass component is configured to generate, through photoluminescence, one or more peaks of higher intensity light corresponding to a wavelength which can be used to monitor a physical condition of a user. The amplified light is sent to the user and received back at a photodetector, which can then algorithmically determine a physical condition of a user.

A glass powder contains, as a glass composition, TeO.sub.2 of 15 mol % to 65 mol %, MoO.sub.3 of 10 mol % to 60 mol %, and P.sub.2O.sub.5 of 1 mol % to 35 mol %, and is substantially free of PbO.