二氧化碳

[ noun ]
a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis
<noun.substance>

Dioxide \Di*ox"ide\ (?; 104), n. [Pref. di- + oxide.] (Chem.)
(a) An oxide containing two atoms of oxygen in each molecule;
binoxide.
(b) An oxide containing but one atom or equivalent of oxygen
to two of a metal; a suboxide. [Obs.]

{Carbon dioxide}. See {Carbonic acid}, under {Carbonic}.


Carbon \Car"bon\ (k[aum]r"b[o^]n), n. [F. carbone, fr. L. carbo
coal; cf. Skr. [,c]r[=a] to cook.] (Chem.)
1. An elementary substance, not metallic in its nature, which
is present in all organic compounds. Atomic weight 11.97.
Symbol C. it is combustible, and forms the base of
lampblack and charcoal, and enters largely into mineral
coals. In its pure crystallized state it constitutes the
diamond, the hardest of known substances, occuring in
monometric crystals like the octahedron, etc. Another
modification is graphite, or blacklead, and in this it is
soft, and occurs in hexagonal prisms or tables. When
united with oxygen it forms carbon dioxide, commonly
called carbonic acid, or carbonic oxide, according to the
proportions of the oxygen; when united with hydrogen, it
forms various compounds called hydrocarbons. Compare
{Diamond}, and {Graphite}.

2. (Elec.) A carbon rod or pencil used in an arc lamp; also,
a plate or piece of carbon used as one of the elements of
a voltaic battery.
[Webster 1913 Suppl.]

3. a sheet of carbon paper.
[PJC]

4. a carbon copy.
[PJC]

{Carbon compounds}, {Compounds of carbon} (Chem.), those
compounds consisting largely of carbon, commonly produced
by animals and plants, and hence called organic compounds,
though their synthesis may be effected in many cases in
the laboratory.

The formation of the compounds of carbon is not
dependent upon the life process. --I. Remsen

{carbon copy}, originally, a copy of a document made by use
of a {carbon paper}, but now used generally to refer to
any copy of a document made by a mechanical process, such
as xerographic copying.

{Carbon dioxide}, {Carbon monoxide}. (Chem.) See under
{Carbonic}.

{Carbon light} (Elec.), an extremely brilliant electric light
produced by passing a galvanic current through two carbon
points kept constantly with their apexes neary in contact.


{Carbon point} (Elec.), a small cylinder or bit of gas carbon
moved forward by clockwork so that, as it is burned away
by the electric current, it shall constantly maintain its
proper relation to the opposing point.

{Carbon paper}, a thin type of paper coated with a
dark-colored waxy substance which can be transferred to
another sheet of paper underneath it by pressing on the
carbon paper. It is used by placing a sheet between two
sheets of ordinary writing paper, and then writing or
typing on the top sheet, by which process a copy of the
writing or typing is transferred to the second sheet
below, making a copy without the need for writing or
typing a second time. Multiple sheets may be used, with a
carbon paper placed above each plain paper to which an
impression is to be transferred. In 1997 such paper was
still used, particularly to make multiple copies of
filled-in purchase invoice forms, but in most applications
this technique has been superseded by the more faithful
xerographic reproduction and computerized printing
processes.

{Carbon tissue}, paper coated with gelatine and pigment, used
in the autotype process of photography. --Abney.

{Gas carbon}, a compact variety of carbon obtained as an
incrustation on the interior of gas retorts, and used for
the manufacture of the carbon rods of pencils for the
voltaic, arc, and for the plates of voltaic batteries,
etc.

Carbonic \Car*bon"ic\, a. [Cf. F. carbonique. See {Carbon}.]
(Chem.)
Of, pertaining to, or obtained from, carbon; as, carbonic
oxide.

{Carbonic acid} (Chem.), an acid {HO.CO.OH}, not existing
separately, which, combined with positive or basic atoms
or radicals, forms carbonates. In common language the term
is very generally applied to a compound of carbon and
oxygen, {CO2}, more correctly called {carbon dioxide}. It
is a colorless, heavy, irrespirable gas, extinguishing
flame, and when breathed destroys life. It can be reduced
to a liquid and solid form by intense pressure. It is
produced in the fermentation of liquors, and by the
combustion and decomposition of organic substances, or
other substances containing carbon. It is formed in the
explosion of fire damp in mines, and is hence called
{after damp}; it is also know as {choke damp}, and
{mephitic air}. Water will absorb its own volume of it,
and more than this under pressure, and in this state
becomes the common soda water of the shops, and the
carbonated water of natural springs. Combined with lime it
constitutes limestone, or common marble and chalk. Plants
imbibe it for their nutrition and growth, the carbon being
retained and the oxygen given out.

{Carbonic oxide} (Chem.), a colorless gas, {CO}, of a light
odor, called more correctly {carbon monoxide}. It is
almost the only definitely known compound in which carbon
seems to be divalent. It is a product of the incomplete
combustion of carbon, and is an abundant constituent of
water gas. It is fatal to animal life, extinguishes
combustion, and burns with a pale blue flame, forming
carbon dioxide.