時(shí)間：2011-03-11 23:18來源：藍(lán)天飛行翻譯 作者：航空 點(diǎn)擊：次
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phase shift. The difference in time between similar points of an output and an input wave. If the input and the output waves pass through zero at the same time, going in the same direction, the waves are in phase. But if the circuit shifts the phase, the output will either lead or lag the input. phase shifter (electronic circuit). A circuit that shifts the phase of an alternating current signal. A phase shifter causes the output signal to either lead or lag the input signal. phenol-formaldehyde resin. One of the oldest of thermosetting plastic resins. Phenol-formaldehyde resin, called phenolic resin, has high strength and good chemical and electrical resistance and is low in cost. It may be reinforced with cloth or paper to make molded plastic objects. phenolic plastic. A plastic material made of a thermosetting phenol-formaldehyde resin, reinforced with cloth or paper. Phenolic plastic materials are used for electrical insulators and control pulleys. Phillips screw. A type of recessed-head screw designed to be driven with a power screwdriver. The recess in the head of a Phillips screw is in the form of a cross, with the sides of the recess tapered and the bottom of the recess nearly flat. A Reed and Prince screw is similar to a Phillips screw, but the edges of the recess in a Reed and Prince screw are straight, rather than tapered, and the bottom of the recess is sharp. See Reed and Prince screw. phonetic alphabet. A list of standard words used for each letter in the alphabet. The use of a standard phonetic alphabet assures that the letters are not misunderstood during radio transmission. See International phonetic alphabet. |
