Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optimizing isotope and vacancy engineering in graphene ribbons to
  enhance the thermoelectric performance without degrading the electronic
  properties
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio