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ix
coordination The formation of a covalent cosine The function cos(x) = e +e −ix . Geo-
2
bond, the two shared electrons of which have metrically, it is the ratio of the lengths of adjacent
come from only one of the two parts of the side to hypotenuse for a right triangle with angle
molecular entity linked by [iut,] as in the reaction x for 0 < x < π .
2
of a Lewis acid and a Lewis base to form a Lewis
adduct; alternatively, the bonding formed in this cosmological constant In general relativity
µν
way. In the former sense, it is the reverse of it is possible to add the term Lg to the energy-
unimolecular heterolysis. “Coordinate cova- momentum tensor, where L is the cosmological
lence” and “coordinate link” are synonymous constant, and g µν is the space-time metric tensor.
(obsolescent)terms. Thesynonym“dativebond” cos x
is also obsolete. (The origin of the bonding cotangent The function cot(x) = sin x . See
electrons has by itself no bearing on the char- cosine, sine.
acter of the bond formed. Thus, the formation of
methyl chloride from a [methylu cation] and a Coulomb gauge In gauge theory the
i
Coulomb gauge is defined by taking ∂ A = 0,
chloride ion involves coordination; the resultant i
where A is the vector potential.
bond obviously differs in no way from the C–
Cl bond in methyl chloride formed by any other
Coulomb potential The Coulomb potential
paty, e.g., by colligation of a methyl radical and n
)(x) of a source function f on R is given by
a chlorine atom.)
Thetermisalsousedtodescribethenumberof )(x) = x − y 2−n f(y)dy.
ligandsaroundacentralatomwithoutnecessarily R n
implying two-electron bonds. For n = 3, this is the potential function for
Newton’s theory of gravitation.
copolymer A polymer derived from more
than one species of monomer. countable additivity A measure µ has
Note: Copolymers that are obtained by the property of countable additivity if given
copolymerization of two monomer species are A ,A ,... asequenceofpairwisedisjoint meas-
2
1
sometimes termed bipolymers, those obtained urable sets then
∞ ∞
from three monomers terpolymers, those
µ( A ) = µ(A ).
obtained from four monomers quaterpoly- i i
i=1 i=1
mers, etc.
countable set A set is countable if it is
copolymerization Polymerization in which either finite or denumerable. See also cardinal-
a copolymer is formed. ity, denumerably infinite set, finite set, infinite set,
and uncountably infinite set.
corrosion An irreversible interfacial reac-
covalent bond A region of relatively high
tion of a material (metal, ceramic, polymer) with
electron density between nuclei which arises at
its environment which results in consumption of
least partly from sharing of electrons and gives
the material or in dissolution into the material of
rise to an attractive force and characteristic inter-
a component of the environment.
nuclear distance.
Often, but not necessarily, corrosion results
in effects detrimental to the usage of the material covariant derivative On a Riemannian
considered. Exclusively physical or mechanical manifold (M, g) the covariant derivative of a
processes such as melting or evaporation, abra- vector field Y along the vector field X is the vec-
sion or mechanical fracture are not included in tor field ∇ Y locally given by
X
the term corrosion.
∂ ∂Y k ∂
j
i
k
∇ Y = X Y N jk i + X j j k
X
cosecant The function csc(x) = 1 . See ∂q ∂q ∂q
sin(x)
sine. where N i are the Christoffel symbols of g.
jk
© 2003 by CRC Press LLC
© 2003 by CRC Press LLC