We present high-resolution observations of two kinds of dynamic behavior in a quiescent prominence using the New Vacuum Solar Telescope , i.e. , Kelvin-Helmholtz instabilities ( KHIs ) and small-scale oscillations .
The KHIs were identified as rapidly developed vortex-like structures with counter-clockwise/clockwise rotations in the H \alpha red-wing images at +0.3 Å , which were produced by the strong shear-flows motions on the surface/interface of prominence plumes .
The KHI growth rates are estimated to be \sim 0.0135 \pm 0.0004 and \sim 0.0138 \pm 0.0004 .
Our observational results further suggest that the shear velocities ( i.e , supersonic ) of the mass flows are fast enough to produce the strong deformation of the boundary and overcome the restraining surface tension force .
This flow-driven instability might play a significant role in the process of plasma transfer in solar prominences .
The small-scale oscillations perpendicular to the prominence threads are observed in the H \alpha line-center images .
The oscillatory periods changed non-monotonically and showed two changing patterns , in which one firstly decreased slowly and then it changed to increase , while the other grew fast at the beginning and then it changed to decrease .
Both of these two thread oscillations with changing periods were observed to be unstable for an entire cycle , and they were local in nature .
All our findings indicate that the small-scale thread oscillations could be magnetohydrodynamic waves in the solar corona .