Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Band edge discontinuities and carrier transport in c-Si/porous silicon
  heterojunctions
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an