Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Hierarchical Nano-Porous Layer with Persistent Superhydrophilicity and
  High Transparency Etched onto Silicate Glass
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph