Abstract: A light-emitting device with high outcoupling efficiency is provided. In the light-emitting device including a light-emitting layer between a pair of electrodes, a low refractive index layer containing an organic compound and an inorganic compound is provided between the light-emitting layer and an anode or between the light-emitting layer and a cathode, and the low refractive index layer has a refractive index of less than or equal to 1.80 at a wavelength of light extracted from the light-emitting layer.

Abstract: A novel light-emitting device with high emission efficiency is provided. A light-emitting device with a high blue index (BI) is provided. A light-emitting device with low power consumption is provided. A light-emitting device including a first electrode and a second electrode which are a reflective electrode and a semi-transmissive and semi-reflective electrode, and an EL layer sandwiched between the first electrode and the second electrode, where the EL layer contains an emission center substance, where when the emission center substance in the EL layer includes only one kind of substance, photon energy of a peak wavelength of light emitted from the light-emitting device is designed from an average value of photon energy of light emitted by the emission center substance in a solution state and emission edge energy on a short wavelength side of an emission spectrum of the emission center substance in the solution state.

Abstract: Provided are electrofused alumina grains capable of preventing grain binding on production and of achieving high grinding performance. The electrofused alumina grains of the present invention contain at least either one of tungsten or molybdenum.

Abstract: Provided are electrofused alumina grains excellent in grinding performance and a production method of such electrofused alumina grains, and a grinding stone and a coated abrasive using the electrofused alumina grains. The electrofused alumina grains of the present invention contain titanium and magnesium. The production method for the electrofused alumina grains includes the steps of: preparing a mixture material by mixing an alumina material, a titanium compound and a magnesium compound, forming an ingot from the mixture material according to an electrofusing process, grinding the ingot to prepare a ground powder, size-regulating the ground powder to have a predetermined grain size to prepare size-regulated grains, and heating the size-regulated grains at a heating temperature of 1,000° C. or higher to give electrofused alumina grains. The grinding stone contains the electrofused alumina grains. The coated abrasive contains the electrofused alumina grains.