Abstract: A microwave device includes a microwave generator generating a microwave and outputting the microwave, a waveguide guiding the microwave output from the microwave generator, a cavity resonator, and a flow tube. In some embodiments, the cavity resonator has an irradiation chamber as a quadrangular prism cavity into which the microwave guided by the waveguide is introduced, resonates the microwave in the irradiation chamber, and generates an electric field in TM110 mode along a direction of a center axis through centers of top and bottom faces of the irradiation chamber. The flow tube is installed in the irradiation chamber and formed in a helical fashion by winding and extending around the center axis, and causes a liquid to be treated to flow in a direction crossing the electric field generated in the irradiation chamber. The center axis is a location where the electric field is the strongest in the irradiation chamber.

Abstract: The present invention relates to a microwave device in which a single-mode cavity resonator is used and uniform and efficient treatment is achieved by increasing a flow rate of a liquid to be treated. The microwave device according to an aspect of the present invention includes a single-mode cavity resonator having an irradiation chamber as a quadrangular prism cavity or a cylindrical cavity, a flow tube installed in the irradiation chamber whose axis line is substantially aligned in a direction of an electric field generated in the irradiation chamber, and an obstacle having a different dielectric constant from the dielectric constant of a liquid to be treated flowing through the flow tube and contained in the flow tube to disturb a flow of the liquid to be treated.

Abstract: In a method for anodizing an aluminum alloy to form an anodic oxide film on a surface of the aluminum alloy using pulsed electric power, a short circuit is formed, after application of a positive pulse voltage, between an anode for anodic oxidation and a cathode for anodic oxidation for a short-circuit duration of not longer than 15 ?s during non application of the pulse voltage. The pulsed electric power has a waveform having a cycle composed, in the order, of a pulse voltage application duration (T+), a dead time (Td) and a short-circuit duration (Ts). Then, no or almost no negative current is allowed to flow, and the film formation rate can be increased to improve productivity.