Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Controlling of ZnO nanostructures by solute concentrationand its effect
  on growth, structural and optical properties   ZnO nanostructured films were prepared by chemical bath deposition method on
glass substrates without any assistance of either microwave or high pressure
autoclaves. The effect of solute concentration on the pure wurtzite ZnO
nanostructure morphologies is studied. The controlling of the solute
concentration help to control nano-structure in the form of nano-needles, and
rods.

14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs