Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The effect of O2 impurities on the low temperature radial thermal
  expansion of bundles of closed single-walled carbon nanotubes
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas