Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Study of axial strain induced torsion of single wall carbon nanotubes by
  2D continuum anharmonic anisotropic elastic model
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol