Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Statistical-mechanical theory of ultrasonic absorption in molecular
  liquids   We present results of theoretical description of ultrasonic phenomena in
molecular liquids. In particular, we are interested in the development of
microscopical, i.e., statistical-mechanical framework capable to explain the
long living puzzle of the excess ultrasonic absorption in liquids. Typically,
ultrasonic wave in a liquid can be generated by applying the periodically
alternating external pressure with the angular frequency that corresponds to
the ultrasound. If the perturbation introduced by such process is weak - its
statistical-mechanical treatment can be done with the use of the linear
response theory. We treat the liquid as a system of interacting sites, so that
all the response/aftereffect functions as well as the energy dissipation and
generalized (wave-vector and frequency dependent) ultrasonic absorption
coefficient are obtained in terms of familiar site-site static and time
correlation functions such as static structure factors or intermediate
scattering functions. To express the site-site intermediate scattering
functions we refer to the site-site memory equations in the mode-coupling
approximation for the first-order memory kernels, while equilibrium properties
such as site-site static structure factors, direct and total correlation
functions are deduced from the integral equation theory of molecular liquids
known as RISM or one of its generalizations. All the formalism is phrased in a
general manner, hence the obtained results are expected to work for arbitrary
type of molecular liquid including simple, ionic, polar, and non-polar liquids.

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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: econ
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The categories of this paper are: nlin
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: stat
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The categories of this paper are: cs