Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Self-assembly of magnetic iron oxide nanoparticles into cuboidal
  superstructures   This chapter describes the synthesis and some characteristics of magnetic
iron oxide nanoparticles, mainly nanocubes, and focus on their self-assembly
into crystalline cuboids in dispersion. The influence of external magnetic
fields, the concentration of particles, and the temperature on the assembly
process is experimentally investigated.

37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg