時(shí)間：2011-03-11 23:13來源：藍(lán)天飛行翻譯 作者：admin 點(diǎn)擊：次
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iso-octane. A flammable, colorless hydrocarbon liquid (CH3)2CHCH2C(CH3)3, used as a component of aviation gasoline and as the datum for rating the antidetonation characteristics of gasoline. The high critical pressure and temperature of iso-octane make it resistant to detonation. isopropyl alcohol. A colorless liquid used in the manufacture of acetone and its derivatives and as a solvent and anti-icing agent. isoshear (meteorology). A line on a weather chart showing equal values of wind shear. isotach (meteorology). A line on a weather chart showing equal, or constant, wind speed. isotherm (meteorology). A line on a weather chart showing equal, or constant, temperature. isothermal (meteorology). This term relates to equal, or constant, temperature with respect to a variable, such as space or time. When referring to the relationship between temperature and height, isothermal is the same as zero lapse rate. isothermal change. A physical change that takes place within a material in which heat energy is added to or taken from the material as needed to keep its temperature constant. isothermal forming (sheet metal forming). A method of forming sheet metal by using heated dies of metal or ceramic. isotope. A special atom of an element having the same number of protons as an ordinary atom, but with more than the normal number of neutrons. An isotope of an element has the same atomic number as a normal atom, but because of the additional neutrons, it has a greater atomic weight. I2R (electrical power). Power dissipated in an electrical circuit computed by multiplying the square of the current by the circuit resistance. I2R loss (electrical power). The power lost in an electrical device, such as a transformer. This power loss is caused by the current flowing through the component resistance. ITT (Interstage Turbine Temperature). The temperature of the gases flowing inside a gas turbine engine between the high-pressure and the low-pressure turbine wheels. J jack (electrical connection). A socket into which a plug can be pushed to make an electrical connection. Jacks are often used on the front of electrical test equipment to make temporary connections for test leads. Some of the more commonly used types of jacks are phone jacks, miniature jacks, microphone jacks, and banana plug jacks. jack (mechanical equipment). A tool used to lift an aircraft or other types of equipment off the floor. Jacks can be operated in several ways: by hydraulic pressure built up by a self-contained pump, by shop air pressure, by mechanical screw threads, or by a ratcheting lever that locks on each stroke. jacket (gas turbine engine component). A shroud or metal blanket used to insulate a portion of the hot section of a gas turbine engine. The jacket keeps heat from damaging the aircraft structure. jack pad. A fixture that attaches to the structure of an aircraft to fit the jack that is used to raise the aircraft for weighing or servicing. |
