资料来源 : pyDict

正电

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Positive \Pos"i*tive\, a. [OE. positif, F. positif, L.
   positivus. See {Position}.]
   1. Having a real position, existence, or energy; existing in
      fact; real; actual; -- opposed to negative. ``Positive
      good.'' --Bacon.

   2. Derived from an object by itself; not dependent on
      changing circumstances or relations; absolute; -- opposed
      to relative; as, the idea of beauty is not positive, but
      depends on the different tastes individuals.

   3. Definitely laid down; explicitly stated; clearly
      expressed; -- opposed to implied; as, a positive
      declaration or promise.

            Positive words, that he would not bear arms against
            King Edward's son.                    --Bacon.

   4. Hence: Not admitting of any doubt, condition,
      qualification, or discretion; not dependent on
      circumstances or probabilities; not speculative;
      compelling assent or obedience; peremptory; indisputable;
      decisive; as, positive instructions; positive truth;
      positive proof. ``'T is positive 'gainst all exceptions.''
      --Shak.

   5. Prescribed by express enactment or institution; settled by
      arbitrary appointment; said of laws.

            In laws, that which is natural bindeth universally;
            that which is positive, not so.       --Hooker.

   6. Fully assured; confident; certain; sometimes,
      overconfident; dogmatic; overbearing; -- said of persons.

            Some positive, persisting fops we know, That, if
            once wrong, will needs be always.     --Pope.

   7. Having the power of direct action or influence; as, a
      positive voice in legislation. --Swift.

   8. (Photog.) Corresponding with the original in respect to
      the position of lights and shades, instead of having the
      lights and shades reversed; as, a positive picture.

   9. (Chem.)
      (a) Electro-positive.
      (b) Hence, basic; metallic; not acid; -- opposed to
          {negative}, and said of metals, bases, and basic
          radicals.

   {Positive crystals} (Opt.), a doubly refracting crystal in
      which the index of refraction for the extraordinary ray is
      greater than for the ordinary ray, and the former is
      refracted nearer to the axis than the latter, as quartz
      and ice; -- opposed to negative crystal, or one in which
      this characteristic is reversed, as Iceland spar,
      tourmaline, etc.

   {Positive degree} (Gram.), that state of an adjective or
      adverb which denotes simple quality, without comparison or
      relation to increase or diminution; as, wise, noble.

   {Positive electricity} (Elec), the kind of electricity which
      is developed when glass is rubbed with silk, or which
      appears at that pole of a voltaic battery attached to the
      plate that is not attacked by the exciting liquid; --
      formerly called {vitreous electricity}; -- opposed to
      {negative electricity}.

   {Positive eyepiece}. See under {Eyepiece}.

   {Positive law}. See {Municipal law}, under {Law}.

   {Positive motion} (Mach.), motion which is derived from a
      driver through unyielding intermediate pieces, or by
      direct contact, and not through elastic connections, nor
      by means of friction, gravity, etc.; definite motion.

   {Positive philosophy}. See {Positivism}.

   {Positive pole}.
      (a) (Elec.) The pole of a battery or pile which yields
          positive or vitreous electricity; -- opposed to
          {negative pole}.
      (b) (Magnetism) The north pole. [R.]

   {Positive quantity} (Alg.), an affirmative quantity, or one
      affected by the sign plus [+].

   {Positive rotation} (Mech.), left-handed rotation.

   {Positive sign} (Math.), the sign [+] denoting plus, or more,
      or addition.

Electricity \E`lec*tric"i*ty\, n.; pl. {Electricities}. [Cf. F.
   ['e]lectricit['e]. See {Electric}.]
   1. A power in nature, a manifestation of energy, exhibiting
      itself when in disturbed equilibrium or in activity by a
      circuit movement, the fact of direction in which involves
      polarity, or opposition of properties in opposite
      directions; also, by attraction for many substances, by a
      law involving attraction between surfaces of unlike
      polarity, and repulsion between those of like; by
      exhibiting accumulated polar tension when the circuit is
      broken; and by producing heat, light, concussion, and
      often chemical changes when the circuit passes between the
      poles or through any imperfectly conducting substance or
      space. It is generally brought into action by any
      disturbance of molecular equilibrium, whether from a
      chemical, physical, or mechanical, cause.

   Note: Electricity is manifested under following different
         forms: (a)

   {Statical electricity}, called also

   {Frictional or Common}, {electricity}, electricity in the
      condition of a stationary charge, in which the disturbance
      is produced by friction, as of glass, amber, etc., or by
      induction. (b)

   {Dynamical electricity}, called also

   {Voltaic electricity}, electricity in motion, or as a current
      produced by chemical decomposition, as by means of a
      voltaic battery, or by mechanical action, as by
      dynamo-electric machines. (c)

   {Thermoelectricity}, in which the disturbing cause is heat
      (attended possibly with some chemical action). It is
      developed by uniting two pieces of unlike metals in a bar,
      and then heating the bar unequally. (d)

   {Atmospheric electricity}, any condition of electrical
      disturbance in the atmosphere or clouds, due to some or
      all of the above mentioned causes. (e)

   {Magnetic electricity}, electricity developed by the action
      of magnets. (f)

   {Positive electricity}, the electricity that appears at the
      positive pole or anode of a battery, or that is produced
      by friction of glass; -- called also {vitreous
      electricity}. (g)

   {Negative electricity}, the electricity that appears at the
      negative pole or cathode, or is produced by the friction
      of resinous substance; -- called also resinous
      electricity. (h)

   {Organic electricity}, that which is developed in organic
      structures, either animal or vegetable, the phrase animal
      electricity being much more common.

   2. The science which unfolds the phenomena and laws of
      electricity; electrical science.

   3. Fig.: Electrifying energy or characteristic.