atmospheric pressure
 氣壓,大氣壓


 atmospheric pressure 名詞
 大氣壓力,大氣壓


 Pres·sure n.
 1. The act of pressing, or the condition of being pressed; compression; a squeezing; a crushing; as, a pressure of the hand.
 2. A contrasting force or impulse of any kind; as, the pressure of poverty; the pressure of taxes; the pressure of motives on the mind; the pressure of civilization.
    Where the pressure of danger was not felt.   --Macaulay.
 3. Affliction; distress; grievance.
    My people's pressures are grievous.   --Eikon Basilike.
    In the midst of his great troubles and pressures.   --Atterbury.
 4. Urgency; as, the pressure of business.
 5. Impression; stamp; character impressed.
    All saws of books, all forms, all pressures past.   --Shak.
 6. Mech. The action of a force against some obstacle or opposing force; a force in the nature of a thrust, distributed over a surface, often estimated with reference to the amount upon a unit's area.
 7. Electro-motive force.
 Atmospheric pressure, Center of pressure, etc. See under Atmospheric, Center, etc.
 Back pressure Steam engine, pressure which resists the motion of the piston, as the pressure of exhaust steam which does not find free outlet.
 Fluid pressure, pressure like that exerted by a fluid. It is a thrust which is normal and equally intense in all directions around a point. --Rankine.
 Pressure gauge, a gauge for indicating fluid pressure; a manometer.

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 At·mos·pher·ic At·mos·pher·ic·al a.
 1. Of or pertaining to the atmosphere; of the nature of, or resembling, the atmosphere; as, atmospheric air; the atmospheric envelope of the earth.
 2. Existing or occurring in the atmosphere.
    The lower atmospheric current.   --Darwin.
 3. Caused, or operated on, by the atmosphere; as, an atmospheric effect; an atmospheric engine.
 4. Dependent on the atmosphere. [R.]
    In am so atmospherical a creature.   --Pope.
 Atmospheric engine, a steam engine whose piston descends by the pressure of the atmosphere, when the steam which raised it is condensed within the cylinder. --Tomlinson.
 Atmospheric line Steam Engin., the equilibrium line of an indicator card. Steam is expanded “down to the atmosphere” when its pressure is equal to that of the atmosphere. (See Indicator card.)
 Atmospheric pressure, the pressure exerted by the atmosphere, not merely downwards, but in every direction. In amounts to about 14.7 Ibs. on each square inch.
 Atmospheric railway, one in which pneumatic power, obtained from compressed air or the creation of a vacuum, is the propelling force.
 Atmospheric tides. See under Tide.

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 atmospheric pressure
      n : the pressure exerted by the atmosphere [syn: air pressure]