Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Image potential of single-wall carbon nanotubes in the field emission
  condition   We calculated the image potentials of single-walled carbon nanotubes of
various structures in the condition of field emission with a quantum chemistry
method. The image potential of the single-walled carbon nanotubes can be well
fitted with the image potential of an ideal metal sphere in a size comparable
to an atom. The image potential is not sensitive to both the applied field and
the structure of the tube. When the image potential is included, the emission
current would be one order larger.

2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom