Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Femtosecond study of the effects of ions on the reorientation dynamics
  of water
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an