Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Why pinning by surface irregularities can explain the peak effect in
  transport properties and neutron diffraction results in NbSe2 and Bi-2212
  crystals?
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph