1,333 research outputs found
Spatial Voting with Endogenous Timing
voting;political economy;games;general equilibrium
Spectroscopy of PTCDA attached to rare gas samples: clusters vs. bulk matrices. I. Absorption spectroscopy
The interaction between PTCDA (3,4,9,10-perylene-tetracarboxylic-dianhydride)
and rare gas or para-hydrogen samples is studied by means of laser-induced
fluorescence excitation spectroscopy. The comparison between spectra of PTCDA
embedded in a neon matrix and spectra attached to large neon clusters shows
that these large organic molecules reside on the surface of the clusters when
doped by the pick-up technique. PTCDA molecules can adopt different
conformations when attached to argon, neon and para-hydrogen clusters which
implies that the surface of such clusters has a well-defined structure and has
not liquid or fluxional properties. Moreover, a precise analysis of the doping
process of these clusters reveals that the mobility of large molecules on the
cluster surface is quenched, preventing agglomeration and complex formation
Zero delay synchronization of chaos in coupled map lattices
We show that two coupled map lattices that are mutually coupled to one
another with a delay can display zero delay synchronization if they are driven
by a third coupled map lattice. We analytically estimate the parametric regimes
that lead to synchronization and show that the presence of mutual delays
enhances synchronization to some extent. The zero delay or isochronal
synchronization is reasonably robust against mismatches in the internal
parameters of the coupled map lattices and we analytically estimate the
synchronization error bounds.Comment: 9 pages, 9 figures ; To appear in Phys. Rev.
Charge Order Breaks Magnetic Symmetry in Molecular Quantum Spin Chains
Charge order affects most of the electronic properties but is believed not to
alter the spin arrangement since the magnetic susceptibility remains unchanged.
We present electron-spin-resonance experiments on quasi-one-dimensional
(TMTTF)2X salts (X= PF6, AsF6 and SbF6), which reveal that the magnetic
properties are modified below TCO when electronic ferroelectricity sets in. The
coupling of anions and organic molecules rotates the g-tensor out of the
molecular plane creating magnetically non-equivalent sites on neighboring
chains at domain walls. Due to anisotropic Zeeman interaction a novel magnetic
interaction mechanism in the charge-ordered state is observed as a doubling of
the rotational periodicity of Delta H.Comment: 9 pages, 13 figure
Vertical pattern of organic matter decomposability in cryoturbated permafrost-affected soils
Permafrost thaw will release additional carbon dioxide into the atmosphere resulting in a positive feedback to climate change. However, the mineralization dynamics of organic matter (OM) stored in permafrost-affected soils remain unclear. We used physical soil fractionation, radiocarbon measurements, incubation experiments, and a dynamic decomposition model to identify distinct vertical pattern in OM decomposability. The observed differences reflect the type of OM input to the subsoil, either by cryoturbation or otherwise, e.g. by advective water-borne transport of dissolved OM. In non-cryoturbated subsoil horizons, most OM is stabilized at mineral surfaces or by occlusion in aggregates. In contrast, pockets of OM-rich cryoturbated soil contain sufficient free particulate OM for microbial decomposition. After thaw, OM turnover is as fast as in the upper active layer. Since cryoturbated soils store ca. 450 Pg carbon, identifying differences in decomposability according to such translocation processes has large implications for the future global carbon cycle and climate, and directs further process model development
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