Abstract: A composition of an etching agent for aluminum or aluminum alloy and a treatment method thereof are provided. The etching agent does not contain a component not suitable for a wastewater treatment, such as boron and fluorine, and has stable etching performance even when performing an etching treatment continuously. The etching agent has excellent aging resistance providing good etching uniformity and corrosion resistance after etching. This etching agent is an etching agent for aluminum or aluminum alloy, including 50 parts by mass of an aminocarboxylic acid, 5 to 300 parts by mass of at least one selected from a hydroxycarboxylic acid, a dicarboxylic acid, a polycarboxylic acid, and salts thereof, and 10 to 800 parts by mass of at least one selected from a hydroxide, a carbonate, and a bicarbonate of an alkali metal, wherein an aqueous solution of the etching agent has a pH of 8 to 10.

Abstract: [Technical Field] A method and a device for artificially generating and showing an aurora. [Problems] To generate and change a true-to-life curtain-shaped discharge light emission by using a simple device. [Means for Solving Problems] As shown in FIG. 1, in a pressure-reduced chamber (1), two electrodes (2) are arranged in X direction and an electrode (3) is arranged in Z direction in such a manner that the two electrodes (2) oppose to the electrode (3) and they are apart from each other. A coil (6) generates a magnetic line of force (m) in the Z direction. [Main Use] Exhibition for public.

Abstract: A photo-pickup wherein a light emitting portion, a surface acoustic wave generating portion, a lens portion, a light receiving portion and a control portion are integrally integrated on a base plate formed on its surface with a light transmission path. The light emitting portion propagates a light beam to the light transmission path. The light beam propagating in the light transmission path is first deflected within a plane of the light transmission path by surface acoustic wave propagating on the light transmission path and propagated towards the lens portion. The lens portion is provided to project the light beam outside from the light transmission path and effect two-dimentional focusing of the projected beam and adjustment of focal position. The light receiving portion comprises a combination of a plurality of light receiving elements disposed at suitable intervals from the projected position of the light beam to receive a reflected light of the light beam.