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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concurrent lines. Lines which pass through a common point. The perpendicular bisectors of the three sides of a triangle all pass through the same point, and these bisectors are concurrent lines. condensation. The process in which a material is changed from one form, or state, into a denser state. For example, water can exist in its vapor state, as steam, and by the process of condensation, the steam can be changed into liquid water. condensation level (meteorology). The height at which a rising parcel or layer of air would become saturated if it were lifted adiabatically — lifted with heat neither added to it nor taken from it. condensation nuclei (meteorology). Small particles in the air on which water vapor condenses or sublimates. condensation trail (meteorology). Cloud-like streamers often seen behind aircraft flying in clear, cold air. Condensation trails are usually called contrails or vapor trails. condenser (air conditioning system component). The component in a vapor-cycle air conditioning system in which the refrigerant gives up the heat it picked up as it passed through the evaporator. This heat is given up to the air flowing through the fins around the condenser tubing. When the refrigerant gives up its heat, it changes state, or condenses from a gas into a liquid. condenser (electrical component). An old term for a capacitor. See capacitor. con-di duct. The British name for a convergent-divergent duct. See convergent-divergent duct. conditionally unstable air (meteorology). Unsaturated air that will be unstable if it becomes saturated. Unstable air rises because it is warmer than the air surrounding it. condition lever (turboprop engine control). An engine control used with a turboprop engine to control the pitch of the propeller for the flight operating range, the alpha range, of operation. conductance (electrical parameter). A measure of the ability of a device to conduct electricity. The symbol for conductance is G, and it was once measured in mhos (ohm spelled backward), but it is now measured in siemens. conduction (thermal). A method of heat transfer by direct contact in which heat energy moves from a higher energy level to a lower level by direct contact. A hand touching a hot stove will be burned because heat energy from the stove is transferred by conduction. conductive coating (electrically conductive material). A finish applied to a nonconductive material to lower the electrical resistance of its surface. A conductive coating on an aircraft component prevents the buildup of static electricity on its surface. conductivity (electrical characteristic). The ability of a material to allow electrons to move freely between its atoms. conductivity (thermal characteristic). The ability of a material to transfer heat by allowing heat energy to pass from one molecule to another within the material. conductor (electrical). A material whose outer shell (valence shell) electrons are held in the atom with a weak force and are therefore able to be moved from one atom to another with a small amount of electrical pressure. Most conductors have three or fewer valence electrons. |
