Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Crossover between hydrodynamic and kinetic modes in binary liquid alloys   Inelastic x-ray scattering (IXS) measurements of the dynamic structure factor
in liquid Na57K43, sensitive to the atomic-scale coarse graining, reveal a
sound velocity value exceeding the long wavelength, continuum value and
indicate the coexistence of two phonon-like modes. Applying Generalized
Collective Mode (GCM) analysis scheme, we show that the positive dispersion of
the sound velocity occurs in a wavelength region below the crossover from
hydrodynamic to atom-type excitations and, therefore, it can not be explained
as sound propagation over the light specie (Na) network. The present result
experimentally proves the existence of positive dispersion in a binary mixture
due to a relaxation process, as opposed to fast sound phenomena.

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The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
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The categories of this paper are: stat
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
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The categories of this paper are: alg-geom
2
The categories of this paper are: math
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
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The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph