Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Strong Visible Absorption and Photoluminescence of Titanic Acid
  Nanotubes by Hydrothermal Method
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin