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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Lacquer is sprayed on the surface as a liquid, and as soon as the solvents and the thinner evaporate, the film base remains as a tough, decorative coating. lagging (lubrication system component). A type of insulation wrapped around some of the lines in an aircraft engine lubrication system to keep it from losing heat in the oil to the outside air. lagging current (electrical current). Current flowing in an AC circuit that has more inductive reactance than capacitive reactance. Voltage changes occur in an inductive circuit before current changes, and the current is said to lag the voltage. LAHSO (land-and-hold-short operations) (air traffic control). Operations which include simultaneous takeoffs and landings and/or simultaneous landings when a landing aircraft is able and is instructed by the controller to hold short of the intersecting runway/taxiway or designated hold-short point. Pilots are expected to promptly inform the controller if the hold-short clearance cannot be accepted. lambert (luminance). The unit of luminance (photometric brightness) that is the same as 1/π (0.3183) candela per square centimeter. laminar flow (aerodynamics). A type of airflow over an airfoil in which the air passes over the surface in smooth layers with a minimum of turbulence. With most airfoils, there is a layer of air adjacent to the surface that flows in a random fashion, even sometimes reversing its direction of flow. This is called the boundary layer. A laminar-flow airfoil is designed in such a way that the boundary layer has a minimum thickness, and nearly all the air flows in smooth layers. Laminar flow of the air decreases the drag produced by the airfoil. laminated core (electrical machinery). The core of an electrical transformer made up of a stack of thin sheets, or laminations, of soft iron or a special highly permeable steel, insulated from each other by an oxide or varnish coating. Eddy currents are induced into the cores of transformers by alternating current flowing in the windings surrounding them, and these eddy currents produce heat and cause electrical losses. The high resistance of the laminated core opposes the flow of eddy current and minimizes the losses. laminated plastic material. A type of reinforced plastic resin made by laminating, or stacking together, layers of cloth, paper, or wood that are impregnated with plastic resin. The layers of the material are forced together by pressure, and the resin is cured with heat. laminated wood. A type of wood product made by gluing together several thin strips of wood. In laminated wood, the grain of all the pieces runs in the same direction. A wooden propeller is made of several pieces of hardwood laminated together. lampblack. A form of almost pure carbon made by burning oil or coal in an atmosphere in which there is not enough oxygen for complete combustion. Lampblack is used for making brushes for electric motors and generators, for the graphite in lead pencils, for the pigment in paint, and for mixing with rubber for making tires. |
