Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High Ultrasonic Transmission Loss Metasurfaces in Water   We report the experimental demonstration of a class of ultrasonic
metasurfaces made of patterned silicon thin wafers partially covered by Si3N4
film that exhibit over 24 dB of sound transmission loss around 0.7 MHz, which
is caused by the cancelation of sound waves emitted by the resonant Si3N4
membrane and the ones through the silicon backbone in each unit cell. These
metasurfaces are expected to have high reflection with little total loss even
at ultrasonic frequency. They could be good candidates as the building blocks
for low-loss cavities, phase zone plates, and other underwater acoustic
metamaterials. As the working principle is scalable, it provides guidance for
the designs of audible underwater sound barriers as well.

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The categories of this paper are: math
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: econ
26
The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: stat
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn