時(shí)間：2011-03-11 23:11來源：藍(lán)天飛行翻譯 作者：admin 點(diǎn)擊：次
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Aluminum alloy corrodes easily, but pure aluminum does not. Alclad sheets are made of high-strength aluminum alloy sandwiched between thin layers of pure aluminum. The coatings of pure aluminum, which are rolled onto the alloy sheet in the rolling mill, make up about five percent of the thickness of the sheet. Alclad sheets resist corrosion as long as the cladding is not scratched through or worn off. alcohol. A colorless, volatile, flammable liquid produced by the fermentation of certain types of grain, fruit, or wood pulp. Alcohol is used as a cleaning fluid, as a solvent in many of aircraft finishes, and as a fuel for certain types of specialized engines. Ethyl alcohol (the alcohol used in liquor) is distilled from fruit or grain, and methyl alcohol, which is poisonous, is distilled from wood pulp. ALERFA (alert phase) (ICAO). A situation in which there is apprehension as to the safety of an aircraft and its occupants. alert area (air traffic control). An area in which there is a high volume of pilot training or an unusual type of aeronautical activity. alerting service. A service provided by the FAA to notify appropriate organizations regarding aircraft in need of search and rescue aid and to assist such organizations as required. algebra. The branch of mathematics that uses letters or symbols to represent numbers in formulas and equations. algebraic expression. A quantity made up of letters, numbers, and other symbols. The parts of the expression separated by a plus or a minus sign are called the terms of the expression. An algebraic expression having only one term is called a monomial, and one with two or more terms is called a polynomial. The algebraic expressions AB, 2Y, and 6X2 are monomials. The expression AB + 2Y - 6X2 is a polynomial. It is actually a trinomial, because it has three terms. algorithm. A systematic set of rules or processes by which a problem can be solved in a specific number of individual steps. alignment (electronic). The adjustment of the components in an electronic circuit so they will be resonant at the required frequency. alignment. The arrangement, or position, of parts of an object or system in correct relationship to each other. alignment pin. A pin installed in a helicopter rotor blade to serve as an index when aligning the blades of a semirigid rotor system. alignment tool (electronic tool). A nonmetallic screwdriver or socket wrench used to adjust trimmer and padder capacitors to align the circuits in a piece of electronic equipment. aliphatic naphtha. A petroleum product similar to gasoline and kerosine. Aliphatic naphtha is used as a cleaning agent to remove grease from a surface prior to painting. alkali. A chemical substance, usually the hydroxide of a metal. An alkali has a characteristically bitter taste and is prone to react with an acid, furnishing the electrons to form a salt. alkaline. Having the property of reacting with an acid to form a salt by give up electrons to the acidic material. |
