Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: UV-Manipulation of Order and Macroscopic Shape in Nematic Elastomers   A range of monodomain nematic liquid crystal elastomers containing differing
proportions of photo-isomerisable mesogenic moieties, which turn from a
rod-like to a kinked shape upon ultraviolet (UV) irradiation, was studied.
Depending on the proportion and positional role of the photo-sensitive groups
in the crosslinked polymer network, different types and magnitudes of response
were found. The principle consequence of such photo-isomerisation is the
destabilisation of the nematic phase, whose order parameter depends on
temperature in a near-critical fashion. Accordingly, the effect of
UV-irradiation is dramatically enhanced near the critical temperature, with the
associated reduction in the nematic order parameter manifesting as a change in
the macroscopic shape of the elastomer samples, producing a large uniaxial
contraction. Theoretical analysis of this phenomenon gives a good quantitative
agreement with experiment.

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The categories of this paper are: atom-ph
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: solv-int
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The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph