Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electromagnetic-radiation absorption of water   Why does a microwave oven work? How does biological tissue absorb
electromagnetic radiation? Astonishingly, we do not have a definite answer to
these simple questions because the microscopic processes governing the
absorption of electromagnetic waves by water are largely unclarified. This
absorption can be quantified by dielectric loss spectra, which reveal a huge
peak at a frequency of the exciting electric field of about 20 GHz and a
gradual tailing off towards higher frequencies. The microscopic interpretation
of such spectra is highly controversial and various superpositions of
relaxation and resonance processes ascribed to single-molecule or
molecule-cluster motions have been proposed for their analysis. By combining
dielectric, microwave, THz, and far-infrared spectroscopy, here we provide
nearly continuous temperature-dependent broadband spectra of water. Moreover,
we find that corresponding spectra for aqueous solutions reveal the same
features as pure water. However, in contrast to the latter, crystallization in
these solutions can be avoided by supercooling. As different spectral
contributions tend to disentangle at low temperatures, this enables to
deconvolute them when approaching the glass transition under cooling. We find
that the overall spectral development, including the 20 GHz feature (employed
for microwave heating), closely resembles the behavior known for common
supercooled liquids. Thus, water's absorption of electromagnetic waves at room
temperature is not unusual but very similar to that of glass-forming liquids at
elevated temperatures, deep in the low-viscosity liquid regime, and should be
interpreted along similar lines.

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The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
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The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn