时间：2011-03-11 23:11来源：蓝天飞行翻译 作者：admin 点击：次
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alkaline cell. A type of primary electrochemical cell that uses powdered zinc as the anode, powdered graphite and manganese dioxide as the cathode, and potassium hydroxide as the electrolyte. An alkaline cell has an open-circuit voltage of 1.5 volts, and it has from 50% to 100% more capacity than a carbon-zinc cell of comparable size. alkyd resin. A type of synthetic resin used as the base for certain enamels and primers. Allen screw. A screw with a hexagonal hole, or socket, in its head. Allen wrench. A hexagonal rod used to turn an Allen screw. The most common Allen wrenches are bent with a 90° angle so they have a short and a long leg. alligator clip. A spring-type clip used on the end of an electrical wire to make temporary connections in an electrical circuit. An alligator clip has long, narrow, spring-loaded jaws with meshing teeth. allowable. Permissible. allowance. The difference between the nominal dimension of a part and its upper or lower limit. alloy. A physical mixture of chemical elements combined with a metal to change its characteristics. alloying agent. A chemical element mixed with a base metal to form an alloy. The alloying agents change the characteristics of the base metal. alloy steel. Steel into which certain chemical elements have been mixed. Alloy steel has different characteristics from those of simple carbon steel. all-weather spark plug. A type of shielded spark plug for use in an aircraft reciprocating engine for high-altitude operation. The ceramic insulator is recessed into the shell to allow a resilient grommet on the ignition harness lead to provide a watertight seal. All-weather spark plugs, also called high-altitude spark plugs, are identified by their 3/4-20 shielding threads. Alnico. The registered trade name for an alloy of iron, aluminum, nickel, and cobalt. Alnico, which has an extremely high permeability and excellent retentivity, is used in the manufacture of permanent magnets. ALNOT (Alert Notice). A message sent by a Flight Service Station or Air Route Traffic Control Center that requests an extensive communications search for an overdue, unreported, or missing aircraft. Alodine. The registered trade name for a conversion-coating chemical which forms a hard, unbroken oxide film on a piece of aluminum alloy. The oxide film produced by Alodine serves the same function as the film produced by anodizing, but does not require an electrolytic bath. Alodine conforms to specifications MIL-C-5541B. Alodizing. A method of corrosion protection by the formation of a hard, airtight oxide coating on the surface of aluminum alloy parts by chemical means. The name is taken from the registered trade name of the chemical Alodine. alpha (transistor operation). A measure of emitter-to-collector current gain of a transistor in a common-base amplifier circuit. Alpha of a junction transistor is never greater than one. Its output is always less than its input. |
