Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of surface layering in a nonmetallic liquid   Oscillatory density profiles (layers) have previously been observed at the
free surfaces of liquid metals, but not in other isotropic liquids. We have
used x-ray reflectivity to study a molecular liquid,
tetrakis(2-ethylhexoxy)silane. When cooled to T/Tc~0.25 (well above the
freezing point for this liquid), density oscillations appear at the surface.
Lateral order within the layers is liquid-like. Our results confirm theoretical
predictions that a surface-layered state will appear even in dielectric liquids
at sufficiently low temperatures, if not preempted by freezing.

12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex