Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Observing visible-range photoluminescence in GaAs nanowires modified by
  laser irradiation
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat