Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theoretical study of subwavelength imaging by acoustic metamaterial
  slabs   We investigate theoretically subwavelength imaging by acoustic metamaterial
slabs immersed in the liquid matrix. A near-field subwavelength image formed by
evanescent waves is achieved by a designed metamaterial slab with negative mass
density and positive modulus. A subwavelength real image is achieved by a
designed metamaterial slab with simultaneously negative mass density and
modulus. These results are expected to shed some lights on designing novel
devices of acoustic metamaterials.

27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
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The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
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The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th