Abstract: An anthraquinone-based active material for a redox flow battery includes a first compound represented by the following chemical formula: where at least one of the R1 to R8 is a hydroxy group, and at least one of the R1 to R8 is an alkoxy group.

Abstract: A method of producing an anthraquinone-based substance represented by the following chemical formula: where at least one of R1 to R8 is a hydroxy group, and at least one of R1 to R8 is an alkoxy group, includes the steps of: preparing a starting material represented by the following chemical formula: where at least two of the R1? to R8? are hydroxy groups; and reacting the starting material with an organic alkylating agent. The amount of the organic alkylating agent to be reacted with the starting material is more than or equal to 0.05 mol and less than n mol per 1 mol of the starting material, where n is the number of hydroxy groups contained in the starting material.

Abstract: Provided are a radiation dosimeter for fluid very small substances, which, in a radiation irradiation device for applying a radiation to a fluid very small substance in a fluid in a treatment chamber, can easily and accurately determine a dose distribution and/or minimum dose of a radiation applied to individual fluid very small substances, and a method of measuring a dose of a radiation applied to fluid very small substances using the dosimeter. In the radiation dosimeter for fluid very small substances, a microcapsule includes a radiation transmitting shell body and a radiation color development tautomeric photochromic solution contained within the shell. The microcapsule undergoes a change in color upon a change in color of the photochromic solution upon exposure to a radiation. The dose of the radiation and the color change level of the microcapsule have a quantitative relationship.

Abstract: Provided are a radiation dosimeter for fluid very small substances, which, in a radiation irradiation device for applying a radiation to a fluid very small substance in a fluid in a treatment chamber, can easily and accurately determine a dose distribution and/or minimum dose of a radiation applied to individual fluid very small substances, and a method of measuring a dose of a radiation applied to fluid very small substances using the dosimeter. In the radiation dosimeter for fluid very small substances, a microcapsule includes a radiation transmitting shell body and a radiation color development tautomeric photochromic solution contained within the shell. The microcapsule undergoes a change in color upon a change in color of the photochromic solution upon exposure to a radiation. The dose of the radiation and the color change level of the microcapsule have a quantitative relationship.