Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structural properties and Raman spectroscopy of lipid Langmuir
  monolayers at the air-water interface   Spectra of octadecylamine (ODA) Langmuir monolayers and egg
phosphatidylcholine (PC)/ODA-mixed monolayers at the air-water interface have
been acquired. The organization of the monolayers has been characterized by
surface pressure-area isotherms. Application of polarized optical microscopy
provides further insight in the domain structures and interactions of the film
components. Surface-enhanced Raman scattering (SERS) data indicate that
enhancement in Raman spectra can be obtained by strong interaction between
headgroups of the surfactants and silver particles in subphase. By mixing ODA
with phospholipid molecules and spreading the mixture at the air-water
interface, we acquired vibrational information of phospholipid molecules with
surfactant-aided SERS effect.

8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex