Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Spontaneous chemical reactions between hydrogen and oxygen in
  nanobubbles
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph