  Inertial-range features of turbulence are investigated using data from
experimental measurements of grid turbulence and direct numerical simulations
of isotropic turbulence simulated in a periodic box, both at the Taylor-scale
Reynolds number $R_\lambda \sim 1000$. In particular, oscillations modulating
the power-law scaling in the inertial range are examined for structure
functions up to sixth order moments. The oscillations in exponent ratios
decrease with increasing sample size in simulations though, in experiments,
they survive at a low value of $4$ parts in $1000$ even after massive
averaging. The two data sets are consistent in their intermittent character but
differ in small but observable respects. Neither the scaling exponents
themselves nor all the viscous effects are consistently reproduced by existing
models of intermittency.
