Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Assisted-hydrothermal Synthesis and Characterization of Flower-like ZnO
  Nanostructures   Flower-like nanostructures formed by ZnO nanorods were synthesized and
deposited on seeded silicon and glass substrates by a hexamethylenetetramine
(HMTA) - assisted hydrothermal method at low temperature (90 oC) with
methenamine ((CH3)6N4), as surfactant and catalyst. The substrates were seeded
with ZnO nanoparticles. The structure and morphology of the nanostructures were
studied by means of x-ray diffraction (XRD), high resolution transmission
electron microscopy (HRTEM), and scanning electron microscopy (SEM) techniques.
Influence of the seed nanoparticle on the formation of the flower-like ZnO
nanostructures is demonstrated. The influence of the organic oxygenated chains
on the crystalline habit during the growth process is also observed.

3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg