Incoherent, inelastic scattering of neutrons by hydrogen in surface hydroxyl groups has been used to probe the dynamics of 60-70-{}-diameter spheres of amorphous silica. The high-temperature spectra indicate a pronounced "small-particle" enhancement of low-frequency vibrational modes as predicted by theory. At low temperatures, the scattering changes in character and shows evidence of hindered rotational transitions.
No takes yet. Share an insight, caveat, or question.
Richter et al. (1980) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: