时间：2011-03-11 23:18来源：蓝天飞行翻译 作者：航空 点击：次
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spar varnish. A hard, durable finish for wood that is to be kept outdoors where it is exposed to the weather. Spar varnish is made of a resin mixed with drying oils and thinners, and it is brushed on the surface to be protected. When the drying oils cure, they leave a hard, protective resin film on the wood. Spar varnish is much more durable than spirit varnish. spatula. A tool that looks much like a knife, but has no cutting edge. The thin, flexible, metal blade of a spatula is used to mix, spread, or move soft materials, such as resins. speaker voice coil. A small coil that rides inside an air gap in a permanent magnet or electromagnet inside a radio speaker. The voice coil is physically attached to the speaker cone, and alternating current from the output of an audio amplifier flows through it. Current flowing in the voice coil produces a magnetic field that either aids or opposes the magnetic field in which the coil is mounted. This interaction between the magnetic fields moves the coil in and out, and as it moves, it vibrates the speaker cone and produces sound waves in the air. special emergency (air traffic control). A condition of air piracy or other hostile act by a person or persons aboard an aircraft which threatens the safety of the aircraft or its passengers. special VFR. 14 CFR Part 1: “Meteorological conditions that are less than those required for basic VFR flight in controlled airspace and in which some aircraft are permitted flight under visual flight rules.” special VFR operations. 14 CFR Part 1: “Aircraft operating in accordance with clearances within controlled airspace in meteorological conditions less than the basic VFR weather minima. Such operations must be requested by the pilot and approved by ATC.” specific fuel consumption. A measure of the amount of fuel burned in a heat engine to produce a given amount of power. Specific fuel consumption of a reciprocating engine is expressed in pounds of fuel burned per hour for each horsepower produced. specific gravity. The ratio of the density of a material to the density of pure water. If the specific gravity of a material is less than 1.0, it will float in water, but if it is greater than 1.0, it will sink. specific heat. The ratio of the amount of heat energy needed to raise the temperature of a specific mass of material one degree Celsius, to the amount of heat energy needed to raise the temperature of the same mass of pure water one °C. Water has a specific heat of 1.0, and copper has a specific heat of 0.093. Therefore, it takes 10.75 (1 / 0.093) times as much heat to raise the temperature of one gram of water one °C as it does to raise the temperature of one gram of copper one °C. specific humidity (meteorology). The ratio, by weight, of the water vapor in a sample of air to the combined weight of the water vapor and the dry air. specific weight (aircraft engine measurement). The ratio of the weight of an aircraft engine to the brake horsepower it produces. |
