时间：2011-03-11 23:18来源：蓝天飞行翻译 作者：航空 点击：次
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solo flight (aircraft flight). Flight of an aircraft when there is only one person in the aircraft. soluble. The condition of a substance that can be dissolved in, or can form a solution with, another substance. Salt is soluble in water, it will dissolve in water to form a solution of salt and water. Oil is soluble in gasoline. Oil and gasoline form a solution when they are mixed. solution. A homogeneous mixture (a mixture that is the same all the way through) of one or more materials dissolved in another. A solution is a physical mixture, because the parts that make up the solution do not have to be combined in any exact ratio, as they do in a compound. Either a little bit, or a large amount of salt can be dissolved in a container of water, to produce a solution of salt water. solution heat treatment (metal heat treatment). A type of heat treatment in which the metal is heated in a furnace until its temperature is uniform throughout. It is then removed from the furnace and quenched in cold water. When the metal is hot, the alloying elements enter into a solid solution with the base metal to become part of its basic structure. When the metal is quenched, the alloying elements remain a part of the base-metal structure. If the metal is not immediately quenched after it is removed from the furnace, some of the alloying elements will precipitate, or settle out, of the solid solution with the base metal, and the grain structure will enlarge. The metal will not be as strong as it would have been if it were properly quenched, and intergranular corrosion is likely to form along the enlarged grain boundaries. solvent. A liquid able to dissolve certain types of solids. Water is a good solvent for some kinds of chemical materials, such as certain types of salts. Alcohol is a solvent for many materials that cannot be dissolved in water. Some of the stronger acids, such as hydrofluoric acid, are used as solvents for materials that cannot be dissolved in any other solvent. sonar. An electronic detection system used for locating objects in water. Pulses of acoustic energy (energy whose frequency is within the range that can be heard by the human ear) is transmitted through the water. This energy travels until it strikes an object, and part of it is reflected back to the sonar receiver where it is amplified and displayed on a scope or dial. Sonar is used by the Navy to detect the presence of submarines and by commercial fishermen to locate schools of fish. Passive sonar does not transmit pulses of energy, but listens for sounds made by the propellers of ships and submarines. sonic boom. A loud, explosive noise heard on the ground when an airplane passes overhead at a speed faster than the speed of sound. Sound-pressure waves build up as the airplane passes through the air, but because the airplane is flying faster than these waves can move out ahead of it, the sound pressure builds up and forms a shock wave. The shock wave radiates out from the airplane in the form of a cone. When this cone passes over the ground, the pressure difference between the pressure inside the wave and the pressure of the surrounding air causes the loud explosion-like sound. |
