Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Laser-assisted coloration of Ti: oxides or nanostructures?   Coloration of a Ti target under its ablation with picosecond laser pulses in
liquids is ascribed to the formation of self-organized nanostructures. The
density of nanostructures increases in an avalanche-like way with the number of
laser pulses. The Raman peaks observed in the laser-exposed areas may be due to
the auto-SERS effect.

33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th