时间：2011-03-11 23:13来源：蓝天飞行翻译 作者：admin 点击：次
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monostable multivibrator (electronic circuit). A type of electronic oscillator that has two conditions. It is stable in one of these conditions and tries to remain in this condition, but a special signal can cause it to shift to the other. As soon as the signal is removed, it automatically returns to its first condition. monsoon (meteorology). A wind that in summer blows from the sea to a continental interior, bringing copious amounts of rain. In the winter this wind blows from the interior to the sea, resulting in sustained dry weather. Morse code. A standardized code of dots and dashes used to transmit information over wires or by radio, using continuous wave (CW) or modulated continuous wave (MCW) radio-frequency energy. The various letters and numbers are made up of combinations of long and short pulses of energy. The long pulses are called dashes, and the short pulses are called dots. See International Phonetic Alphabet and Morse Code in Appendix 4. MOS capacitor (metal oxide semiconductor capacitor). A capacitor that uses a semiconductor material as one plate, a thin film of silicon oxide as the dielectric, and a tiny spot of metal plated on the oxide as the other plate. MOS capacitors used as temporary storage devices in a digital computer are called dynamic RAMs (random access memories). MOSFET (metal-oxide silicon field-effect transistor). A semiconductor device that consists of P-type source and drain regions diffused into a substrate of N-type silicon. A substrate is the supporting material on which an integrated circuit chip is built. The source and drain are on either side of a narrow channel of N-material, and an insulating layer of silicon oxide is deposited over the substrate so it covers the source, the drain, and the channel between them. A gate connection is formed between the source and the drain, and it is insulated from them by the oxide film. A control voltage applied to the gate causes the material in the channel to act as though it were P-type material, and electrons flow from the source to the drain without having to cross a P-N junction. The source and drain of a MOSFET serve the same functions as the emitter and collector of a bipolar transistor. However, the source and drain can be interchanged, while the emitter and collector of a bipolar transistor cannot. mothball (equipment storage). A term used for the preservation of equipment or machinery. When something is mothballed, it is sealed so moisture cannot get into it. |
