Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical Constants and Functions of Corundum Single Crystals in the
  Vacuum Ultraviolat Region   Optical reflection spectra of corundum single crystals grown by HOC and
Verneil methods are investigated before and after irradiated by electrons and
neutrons using synchrotron radiation polarization (5-30eV).

14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
19
The categories of this paper are: eess
18
The categories of this paper are: econ
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg