1,559 research outputs found
Optical probe of carrier doping by X-ray irradiation in organic dimer Mott insulator -(BEDT-TTF)Cu[N(CN)Cl
We investigated the infrared optical spectra of an organic dimer Mott
insulator -(BEDT-TTF)Cu[N(CN)]Cl, which was irradiated with
X-rays. We observed that the irradiation caused a large spectral weight
transfer from the mid-infrared region, where interband transitions in the dimer
and Mott-Hubbard bands take place, to a Drude part in a low-energy region; this
caused the Mott gap to collapse. The increase of the Drude part indicates a
carrier doping into the Mott insulator due to irradiation defects. The strong
redistribution of the spectral weight demonstrates that the organic Mott
insulator is very close to the phase border of the bandwidth-controlled Mott
transition.Comment: 4 pages, 4 figure
Cross-correlation between the 21-cm signal and [OIII] emitters during early cosmic reionization
We study statistics of the 21-cm signal from the epoch of reionization. We
propose to use [OIII] line emitting galaxies to cross-correlate with the 21-cm
signal from . To this aim, we employ simulations of reionization
obtained post-processing the high-resolution cosmological hydrodynamic
simulation Massive Black-II with the three-dimensional (3D) radiative transfer
code CRASH to follow the propagation of ionizing photons from a variety of
sources. We show that, during the early phases of reionization, the 21-cm
signal is positively correlated with the spatial distribution of the [OIII]
emitters on large scales . This positive correlation is
generated by the temperature-galaxy correlation and it is a few times larger
than when we assume that the heating is saturated. As the reionized regions
expand, the correlation changes its sign to negative from to 8. The
signals at this epoch can be detected by combining the Square Kilometre Array
(SKA) and a wide-field [OIII] emitter survey. We also calculate the cross-power
spectrum with a 3D [OIII] intensity field, aiming at exploiting future
intensity mapping observations. We conclude that high-redshift [OIII] line
emitters can be used to probe the reionization process when the intergalactic
medium is largely neutral.Comment: 7 pages, 5 figures, published in MNRA
Electrospray ionization mass spectrometric observation of ligand exchange of zinc pyrithione with amino acids
ArticleRAPID COMMUNICATIONS IN MASS SPECTROMETRY. 23(14):2161-2166 (2009)journal articl
Raman tensor analysis of hexagonal polyoxymethylene and its application to study the molecular arrangement in highly crystalline electrospun nanofibers
The orientation dependence in space of Raman-active vibrations in the hexagonal structure of polyoxymethylene (POM) is discussed in terms of Raman tensor elements as intrinsic physical parameters of the lattice. The variation of polarized intensity for the A1 and the E1 vibrational modes with respect to the POM molecular orientation is systematically studied, from both theoretical and experimental viewpoints, according to the symmetry assignments of each vibrational mode. A set of working equations including the Raman selection rules associated with the A1 and the E1 modes and the orientation distribution function are explicitly formulated and validated by means of a least-square fitting procedure on experimental data. In addition, an approach based on the introduction of orientation distribution functions is applied to quantitatively assess and compare on a statistical base the molecular orientation of two different types of electrospun POM nanofibers. Copyright (c) 2012 John Wiley & Sons, Ltd
Stability conditions and positivity of invariants of fibrations
We study three methods that prove the positivity of a natural numerical
invariant associated to parameter families of polarized varieties. All
these methods involve different stability conditions. In dimension 2 we prove
that there is a natural connection between them, related to a yet another
stability condition, the linear stability. Finally we make some speculations
and prove new results in higher dimension.Comment: Final version, to appear in the Springer volume dedicated to Klaus
Hulek on the occasion of his 60-th birthda
- âŠ