时间：2011-03-11 23:13来源：蓝天飞行翻译 作者：admin 点击：次
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hygrograph (meteorology). The record produced by a continuous-recording hygrometer. hygrometer. An instrument used to measure the amount of moisture in the air to determine its humidity. hygroscopic material. A material that absorbs moisture from the air. Silica gel is a hygroscopic material used to protect delicate equipment from damage caused by moisture in the air. When bags of silica gel are placed in the equipment, any moisture in the air is absorbed by the silica gel, and the air is kept dry. hyperbola (mathematical curve). A plane curve traced by a point that moves in such a way that the difference of its distance from two fixed points, called foci, remains constant. hyperbolic navigation system. A system of electronic navigation in which a master and a remotely located slave station transmit a signal simultaneously. The difference between the time the signals from the two stations are received in an aircraft is carefully measured and plotted on a chart of hyperbolic curves. This information gives a line of position along which the aircraft is located. An electronic computer determines the position by plotting lines of position from two sets of stations. The aircraft is located at the latitude and longitude the lines cross. hyper engines. A series of experimental high-performance aircraft engines built with U.S. Army and Navy financing in the early 1930s. The goal of these engines, which had been unattainable up to that time, was to develop one horsepower for each cubic inch of piston displacement. hypoxia. A physiological condition in which a person is deprived of the needed oxygen. The effects of hypoxia normally disappear as soon as the person is able to breathe air that contains sufficient oxygen. |
