  We present the first next-to-leading-order QCD analysis of neutrino charm
production, using a sample of 6090 $\nu_\mu$- and $\bar\nu_\mu$-induced
opposite-sign dimuon events observed in the CCFR detector at the Fermilab
Tevatron. We find that the nucleon strange quark content is suppressed with
respect to the non-strange sea quarks by a factor $\kappa = 0.477 \:
^{+\:0.063}_{-\:0.053}$, where the error includes statistical, systematic and
QCD scale uncertainties. In contrast to previous leading order analyses, we
find that the strange sea $x$-dependence is similar to that of the non-strange
sea, and that the measured charm quark mass, $m_c = 1.70 \pm 0.19 \:{\rm
GeV/c}^2$, is larger and consistent with that determined in other processes.
Further analysis finds that the difference in $x$-distributions between $xs(x)$
and $x\bar s(x)$ is small. A measurement of the Cabibbo-Kobayashi-Maskawa
matrix element $|V_{cd}|=0.232 ^{+\:0.018}_{-\:0.020}$ is also presented.
uufile containing compressed postscript files of five Figures is appended at
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