摘要:
An electric wire includes a conductive portion 11 made of a material having a volume resistivity higher than that of copper, wherein the volume resistivity of the conductive portion is specified so that, in a frequency range in which the electric wire is used, a ratio of AC resistance of the conductive portion 11 to AC resistance of reference copper wire is less than 1.
摘要:
In an optical fiber laying structure for an electric power cable line trouble occurrence location detecting system for detecting a trouble occurrence location by laying an optical fiber along an electric power cable line, the portion of the optical fiber laid along the cable of one of the two adjacent sections is superposed on the portion of the optical fiber laid along the cable of the other sections in an area in the vicinity of the boundary of the electric power cable line. Thus, if a temperature rise occurs due to a trouble such as a ground-fault in the boundary area, the temperature peak position, i.e., the trouble occurrence location can be detected by the two different optical fibers. Therefore, the trouble occurrence location in the boundary area can be accurately detected.
摘要:
A high frequency cable includes: a central conductor made from aluminum or an aluminum alloy; a covering layer made from copper covering the central conductor, and having a fiber-like structure in a longitudinal direction; and an intermetallic compound layer formed between the central conductor and the covering layer and having greater volume resistivity than the covering layer, wherein a cross-sectional area of the covering layer is 15% or less of an entire cross-sectional area including the central conductor, the intermetallic compound layer and the covering layer.
摘要:
A temperature abnormality detecting structure for a fluid pipe detects a temperature abnormality location by laying an optical fiber serving as a temperature detecting portion of a Ramam scattering optical fiber distribution type temperature sensor along a fluid pipe. The fluid pipe is divided into a plurality of sections in the longitudinal direction, independent optical fibers are laid along the fluid pipe in the respective sections. A portion of the optical fiber laid along one of the adjacent sections is superposed to be laid on a portion of the optical fiber laid along the other of the adjacent sections in the vicinity of each of the respective boundaries of the sections. Since the portion of the optical fiber laid along the pipe of one of the two adjacent sections is superposed on the portion of another optical fiber laid along the pipe of the other of the adjacent sections, if an abnormal temperature change occurs due to a trouble such as leakage or outflow of the fluid from the pipe in the boundary area, the temperature change peak position, i.e., the abnormality occurrence locations is detected by the two different optical fibers. Thus, the detecting accuracy is remarkably enhanced as compared with a case wherein the abnormality is detected by only one optical fiber.
摘要:
An electric wire includes a conductive portion 11 made of a material having a volume resistivity higher than that of copper, wherein the volume resistivity of the conductive portion is specified so that, in a frequency range in which the electric wire is used, a ratio of AC resistance of the conductive portion 11 to AC resistance of reference copper wire is less than 1.
摘要:
A projection optical system for use in a precise copy which uses a pair of catadioptric optical systems consisting of convex mirrors, concave mirrors, and phase correction members is shown. Two catadioptric optical systems commonly use an entrance pupil on a coaxis and are coupled so as to respectively face the phase correction members. Each of the concave mirrors has an opening at the center. Each of the convex mirrors has no opening in one embodiment but has an opening portion at the center in another embodiment.
摘要:
A projection optical system for photolithography includes a refraction sub-system and a cata-dioptric sub-system optically connected to each other. The refraction sub-system extends at an object side. The cata-dioptric sub-system extends at an image side. The refraction sub-system is generally composed of refracting members. The cata-dioptric sub-system is generally composed of a phase compensating member, a concave mirror, and a convex mirror. The phase compensating member adjoins the refraction sub-system. At least the concave mirror has a central opening through which light passes. The light forms an image at a rear of the concave mirror.
摘要:
A DC power cable includes a conductor and an insulation of a thermoplastic resin formed around the conductor. The insulation contains carbon black in an amount of about 0.2 to about 5% of the total weight of the thermoplastic resin and the carbon black, and the ratio of mineral oil absorption (cc/100 g) to specific surface (m.sup.2 /g) in the carbon black is not less than 0.7. The carbon black has the hydrogen content of not more than 0.6% by weight. The specific surface is measured by BET equation. The carbon black has a particle size of 10 to 100 nm.
摘要:
A method is disclosed in which an insulating film of an oxide of metal, of which a stranded conductor (30) is made, is formed on the surface of all strands in a stranded conductor, while the stranded conductor is held in the stranded form. In a step of oxidation-treating the strands of an electric cable the pressure of an oxidation treatment solution at the outer portion of the stranded conductor immersed therein is made higher than the pressure in the inner portion of the stranded conductor (30), causing the oxidation treatment solution (48) to be adequately penetrated from the outer portion into the inner portion of the stranded conductor to permit a desired oxide film to be formed on the surface of all the strands in the stranded conductor. In order to more facilitate the penetration of the oxidation treatment solution (48) wholly into the interior of the stranded conductor (30) and the more facilitate an oxidation reaction, vibrations are, in addition to this method, imparted to the stranded conductor (30) in the oxidation treatment step (40) to cause the untwisting of the stranded conductor (30) to be effected to some extent, while the stranded conductor being heated is entered into this step.
摘要:
A high frequency cable includes: a central conductor made from aluminum or an aluminum alloy; a covering layer made from copper covering the central conductor, and having a fiber-like structure in a longitudinal direction; and an intermetallic compound layer formed between the central conductor and the covering layer and having greater volume resistivity than the covering layer, wherein a cross-sectional area of the covering layer is 15% or less of an entire cross-sectional area including the central conductor, the intermetallic compound layer and the covering layer.