| 摘要 |
<p>474,277. Asymmetrically conducting resistances. BARREY, E. Jan. 11, 1937, Nos. 859 and 860. Convention dates, Jan. 16, 1936 and Aug. 27, 1936. [Class 37] Copper elements, oxidized at about 1000‹ C., are dipped into a conducting medium, at about the same temperature, such as graphite, a fused mineral salt, manganese dioxide or powdered copper oxide. Electric current is then passed through the oxide layers and continued while the conducting medium slowly cools. The current is of the order of several amperes to the square centimetre. This facilitates the crystallization of the oxide layer. After this treatment the black oxide layer is subjected to an electrolytic action and reduced, an iron electrode being placed in contact with the oxide surface. In a modification, the conducting medium may comprise a reducing body and the copper elements are removed from the bath before the red cuprous oxide layer is affected. This layer may then be covered with an electrolytic metal deposit in a bath of a salt of the metal to be deposited by placing the electrodes for example of silver and of zinc in contact with the oxide layer on the same face and applying an alternating voltage.</p> |
