时间：2011-03-11 23:11来源：蓝天飞行翻译 作者：admin 点击：次
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The contact area of a cup-point fastener is a circular ridge which makes a slight depression in the surface onto which it is tightened. Cup points are used for set screws. cup washer. A form of lock washer made of spring steel formed into the shape of a cup. When the nut is tightened on a cup washer, the washer compresses, and its spring action holds pressure between the threads in the nut and those in the bolt. This pressure prevents vibration from loosening the nut. cure (plastic resin condition). A step in the manufacture of parts made from plastic resins. The components of the resin are mixed, and heat produced in the resin or heat applied externally causes the resin to cure, or change into a compound different from that of its components. cure time (plastic resin). The amount of time needed for a plastic resin to change from a liquid into a solid. curium. A silvery, metallic, synthetic, radioactive chemical element. Curium’s symbol is Cm, and its atomic number is 96. current (electricity). A term used to describe the flow of electricity. Electron current is the flow of electrons in a circuit. They move through a circuit from the negative terminal of the source of electrical energy to its positive terminal. Conventional current is an assumed flow of electricity which travels from positive to negative. It was only after the discovery that it is the negative electrons that actually move in an electrical circuit that the concept of electron current was developed. Previous to this discovery, many texts were written using the positive to negative direction of flow. For this reason, positive to negative flow is called conventional current. Current is measured in amperes, with one ampere being the rate of flow of one coulomb per second. See coulomb. current amplifier (electronic circuit). An electronic amplifier in which the current in its output circuit is greater than the current in its input circuit. current density. The ratio found by dividing the total amount of current flowing through a conductor, in amperes, by the cross-sectional area of the conductor, in square inches. Current density is measured in amperes per square inch. current electricity. The form of electricity which makes use of the heat and/or the magnetic field produced when electrons flow in a conductor. current-fed antenna (radio transmitting antenna). A center-fed radio transmitting antenna that is half a wavelength long. current flight plan (ICAO). The flight plan including changes, if any, brought about by subsequent clearances. current limiter (generator control component). A device in the control system of a DC generator which reduces the output voltage or removes the generator from the electrical system any time it produces more than its rated current. Some current limiters are a type of slow-blow fuse in the generator output circuit which removes the generator from the electrical system if its output becomes excessive. Other current limiters reduce the generator output voltage if it tries to put out more than its rated current. |
