1,906 research outputs found
Pump Built-in Hamiltonian Method for Pump-Probe Spectroscopy
We propose a new method of calculating nonlinear optical responses of
interacting electronic systems. In this method, the total Hamiltonian (system +
system-pump interaction) is transformed into a different form that (apparently)
does not have a system-pump interaction. The transformed Hamiltonian, which we
call the pump built-in Hamiltonian, has parameters that depend on the strength
of the pump beam. Using the pump built-in Hamiltonian, we can calculate
nonlinear responses (responses to probe beams as a function of the pump beam)
by applying the {\em linear} response theory. We demonstrate the basic idea of
this new method by applying it to a one-dimensional, two-band model, in the
case the pump excitation is virtual (coherent excitation). We find that the
exponent of the Fermi edge singularity varies with the pump intensity.Comment: 6 page
Willingness to pay for municipality hospital services in rural Japan: a contingent valuation study
<p>Abstract</p> <p>Background</p> <p>The Japanese healthcare system has undergone reforms to address the struggles that municipality hospitals face. Reform guidelines clearly define criteria for administrative improvement. However, criteria to evaluate the demand for healthcare provisions in rural Japan, including the needs of rural residents for municipality hospitals in particular have not been specified. The purpose of this paper is to measure residents' willingness to pay (WTP) for municipality hospital services using the contingent valuation method, and to evaluate municipality hospital valuation on the basis of WTP. K town, located in the Hokkaido prefecture of Japan, was selected as the location for this study. Participants were recruited by a town hall healthcare administrator, hospital and clinic staff, and a local dentist. Participants were asked what amount they would be willing to pay as taxes to continue accessing the services of the municipality hospital for one year by using open-ended questions in face-to-face interviews.</p> <p>Findings</p> <p>Forty-eight residents were initially recruited, and 40 participants were selected for the study (response rate 83%). As compared to K town's population, this data slanted toward the elderly, although there was no significant difference in frequency among the characteristics. The median WTP was estimated at 39,484 yen (308.95-615.96). Logistic regression revealed no significant factors affecting WTP.</p> <p>Conclusions</p> <p>If the total amount of residents' WTP for the municipality hospital were to be estimated by this result, it would calculate with 129,586,000 yen ($1,439,844). This is approximately equal to the amount of money to be transferred from the general account of the government of K town, more than one-half of the town tax of K town, and about two-fold in comparison to Japan as a whole. This showed that K town's residents placed a high valuation on the municipality hospital, which nearly equalled the amount that the K town government provided to the municipality hospital to cover its annual deficit. K town residents had come to expect not only general clinical practice, but also emergency medical services and night practice provided by their own town's municipality hospital. WTP can be used as a measure of hospital evaluation because it reflects the importance of the hospital to the residents in its region.</p
Emitter-site selective photoelectron circular dichroism of trifluoromethyloxirane
The angle-resolved inner-shell photoionization of R-trifluoromethyloxirane,
C3H3F3O, is studied experimentally and theoretically. Thereby, we investigate
the photoelectron circular dichroism (PECD) for nearly-symmetric O 1s and F 1s
electronic orbitals, which are localized on different molecular sites. The
respective dichroic and angular distribution parameters
are measured at the photoelectron kinetic energies from 1 to 16 eV by using
variably polarized synchrotron radiation and velocity map imaging spectroscopy.
The present experimental results are in good agreement with the outcome of ab
initio electronic structure calculations. We report a sizable chiral asymmetry
of up to about 9% for the K-shell photoionization of oxygen atom.
For the individual fluorine atoms, the present calculations predict asymmetries
of similar size. However, being averaged over all fluorine atoms, it drops down
to about 2%, as also observed in the present experiment. Our study demonstrates
a strong emitter- and site-sensitivity of PECD in the one-photon inner-shell
ionization of this chiral molecule
Nuclei beyond the drip line
In a Thomas-Fermi model, calculations are presented for nuclei beyond the
nuclear drip line at zero temperature. These nuclei are in equilibrium by the
presence of an external gas, as may be envisaged in the astrophysical scenario.
We find that there is a limiting asymmetry beyond which these nuclei can no
longer be made stable.Comment: Physical Review C (in press), 1 ReVteX file for text, 4 PS-files for
figure
Ultrafast photoinduced reflectivity transients in
The temperature dependence of ultrafast photoinduced reflectivity transients
is reported in NdSrMnO thin film. The photoinduced
reflectivity shows a complex response with very different temperature
dependences on different timescales. The response on the sub-ps timescale
appears to be only weakly sensitive to the 270K-metal-insulator phase
transition. Below K the sub-ps response displays a two component
behavior indicating inhomogeneity of the film resulting from the substrate
induced strain. On the other hand, the slower response on the 10-100 ps
timescale is sensitive only to the metal-insulator phase transition and is in
agreement with some previously published results. The difference in the
temperature dependences of the responses on nanosecond and s timescales
indicates that thermal equilibrium between the different degrees of fredom is
established relatively slowly - on a nanosecond timescale
Ultrafast Photoinduced Formation of Metallic State in a Perovskite-type Manganite with Short Range Charge and Orbital Order
Femtosecond reflection spectroscopy was performed on a perovskite-type
manganite, Gd0.55Sr0.45MnO3, with the short-range charge and orbital order
(CO/OO). Immediately after the photoirradiation, a large increase of the
reflectivity was detected in the mid-infrared region. The optical conductivity
spectrum under photoirradiation obtained from the Kramers-Kronig analyses of
the reflectivity changes demonstrates a formation of a metallic state. This
suggests that ferromagnetic spin arrangements occur within the time resolution
(ca. 200 fs) through the double exchange interaction, resulting in an ultrafast
CO/OO to FM switching.Comment: 4 figure
Electronic structure and x-ray magnetic dichroism in random substitutional alloys of f-electron elements
The Koringa-Kohn-Rostoker —coherent-potential-approximation method combines multiple-scattering theory and the coherent-potential approximation to calculate the electronic structure of random substitutional alloys of transition metals. In this paper we describe the generalization of this theory to describe f-electron alloys. The theory is illustrated with a calculation of the electronic structure and magnetic dichroism curves for a random substitutional alloy containing rare-earth or actinide elements from first principles
OntoEPFS: uma ontologia para experimentos em mapeamento digital de solos.
A descrição formal de experimentos para aquisição, tratamento, análises de dados, compartilhamento e reprodução dos resultados obtidos é fundamental para os cientistas envolvidos. Ontologias vêm sendo utilizadas para criar modelos formais para disseminação de informação e conhecimento. Este artigo apresenta uma ontologia para apoiar o Experimento de Predição de Informações de Fertilidades de Solos (OntoEPFS) em Mapeamento Digital de Solos (DSM). O EPFS se encontra em desenvolvimento na Empresa Brasileira de Pesquisa Agropecuária, no Centro Nacional de Pesquisa em Solos ? Embrapa Solos. A adoção dessa ontologia, por parte da Embrapa Solos, facilitará a descrição, a formalização e a disponibilização de conhecimentos sobre os experimentos realizados por esta unidade.SBIAgro 2009
Nonlinear Optical Response Functions of Mott Insulators Based on Dynamical Mean Field Approximation
We investigate the nonlinear optical susceptibilities of Mott insulators with
the dynamical mean field approximation. The two-photon absorption (TPA) and the
third-harmonic generation (THG) spectra are calculated, and the classification
by the types of coupling to external fields shows different behavior from
conventional semiconductors. The direct transition terms are predominant both
in the TPA and THG spectra, and the importance of taking all types of
interaction with the external field into account is illustrated in connection
with the THG spectrum and dcKerr effect. The dependence of the TPA and THG
spectra on the Coulomb interaction indicate a scaling relation. We apply this
relation to the quantitative evaluation and obtain results comparable to those
of experiments.Comment: 14 pages, 12 figure
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