Abstract: A light-emitting element, in which a light whose emission angle distribution is one of Lambert's emission law or uniform Isotropic emission, is extracted from a light extraction opening window, and an in-plane distribution of a light intensity on a light extraction surface of the light extraction opening window is uniform, and which can be used as a reference light source when measuring an absolute light quantity of a weak light emitted from a luminous body which is a measurement object.

Abstract: A light-emitting element, in which a light whose emission angle distribution is one of Lambert's emission law or uniform Isotropic emission, is extracted from a light extraction opening window, and an in-plane distribution of a light intensity on a light extraction surface of the light extraction opening window is uniform, and which can be used as a reference light source when measuring an absolute light quantity of a weak light emitted from a luminous body which is a measurement object.

Abstract: An electrophoresis separation layer is produced which comprises a polyacrylamide gel which remains stable even when stored for a long time and is available for analyzing substances of an extremely wide molecular weight range in electrophoresis for determining molecular weight. The electrophoresis separation layer of the present invention includes a polyacrylamide gel with an aqueous solution containing an amine of a specific pH value, an ampholyte and an acid at a specific ratio as an electrolytic solution in the gel. This separation layer can be produced by lowering the pH value of the electrolytic solution in the polyacrylamide gel to such an extent as not to cause any hydrolysis of amide while achieving a suitable potential gradient distribution in the gel during the electrophoresis.

Abstract: Disclosed are a method and an apparatus for determining catecholic compounds and their related compounds contained in a substance by utilizing the specific reactivity of the compounds with ferric chloride and potassium ferricyanide as reaction reagents. The reaction products are analyzed by spectrophotometry, preferably in combination with high-performance liquid chromatography, so as to determine catecholic compounds and their related compounds.