553 research outputs found
Two-Step Contribution to Intermediate Energy (p,p') and (p,n) Reactions
We calculate the two-step contribution to (p,p') and (p,n) reactions at
intermediate energy. We describe the motion of the incident nucleon with plane
wave and compare the contribution from the two-step processes with that from
the one-step processes. To describe the two-step processes, we extende the
response functions into the nondiagonal ones with respect to the momentum
transfer q.
We performed a numerical calculation for the cross sections of the C,
Ca(p,p') scatterings and the spin longitudinal and the spin transverse
cross sections of the C,Ca(p,n) reactions at 346 MeV and 494 MeV.
We found that the two-step contribution is appreciable in comparison with the
one-step processes in higher energy transfer region for the spin longitudinal
and the spin transverse (p,n) reactions. We also found that the two-step
processes give larger contribution to the spin transverse (p,n) reaction than
to the spin longitudinal reaction. This finding is very encouraging to
interpret the discrepancy between the DWIA calculation and the experimental
results of the spin longitudinal and the spin transverse cross sections.Comment: LaTeX, 18 pages, 11 Postscript file
Two-step contribution to the spin-longitudinal and spin-transverse cross sections of the quasielastic (p,n) reactions
The two-step contribution to the spin-longitudinal and the spin-transverse
cross sections of ^{12}C,^{40}Ca(p,n) reactions at 494 MeV and 346 MeV is
calculated. We use a plane-wave approximation and evaluate the relative
contributions from the one-step and the two-step processes. We found that the
ratios of the two-step to the one-step processes are larger in the
spin-transverse cross sections than in the spin-longitudinal ones. Combining
these results with the distorted-wave impulse approximation (DWIA) results we
obtained considerable two-step contributions to the spin-longitudinal and the
spin-transverse cross sections. The two-step processes are important in
accounting for the underestimation of the DWIA results for the
spin-longitudinal and the spin-transverse cross sections.Comment: LaTeX 11 pages, 10 figure
Improvement of Production Rate of YBCO Coated Conductors Fabricated by TFA-MOD Method
AbstractThe metal-organic deposition (MOD) method using trifluoroacetate (TFA) salts is considered to be an effective method for inexpensively fabricating YBa2Cu3O7-y (YBCO) coated conductors with high critical current density property. The long-length TFA-MOD YBCO coated conductors have been fabricated by multi-turn reel-to-reel system. Increasing the thickness per single coating in the multi-turn reel-to-reel system is a cost-effective technique for fabrication of the precursor films in the calcination process since it reduces the number of coatings and shortens the processing time. In this work, we have developed a new starting solution consisting of non-fluorine salts of yttrium propionate and copper 2-ethylhexanoate with focusing on increasing the thickness per single coating for a high-rate fabrication of the YBCO coated conductors by the TFA-MOD method. The critical thickness per single coating of the precursor film fabricated from the new starting solution was improved to 0.44ÎĽm/coat. Furthermore, the addition of diacetoneacrylamide in the new starting solution increased the critical thickness per single coating to 0.79ÎĽm/coat. High critical current of 791 A/cm-width with high critical current density of 2.7 MA/cm2 was obtained using the new starting solution with diacetoneacrylamide at the thickness per single coating of 0.49ÎĽm/coat
Direct observation of acoustic phonon mediated relaxation between coupled exciton states in a single quantum dot molecule
We probe acoustic phonon mediated relaxation between tunnel coupled exciton
states in an individual quantum dot molecule in which the inter-dot quantum
coupling and energy separation between exciton states is continuously tuned
using static electric field. Time resolved and temperature dependent optical
spectroscopy are used to probe inter-level relaxation around the point of
maximum coupling. The radiative lifetimes of the coupled excitonic states can
be tuned from ~2 ns to ~10 ns as the spatially direct and indirect character of
the wavefunction is varied by detuning from resonance. Acoustic phonon mediated
inter-level relaxation is shown to proceed over timescales comparable to the
direct exciton radiative lifetime, indicative of a relaxation bottleneck for
level spacings in the range $\Delta E\$ ~3-6 meV.Comment: 6 pages, 4 figures, submitted for publicatio
A method using granulated coal ash for disposal of the sludge carried by tsunami
Large amounts of sludge and debris accumulated on agricultural and residential areas after the Great East\ud
Japan Earthquake. Since the sludge carried by the Tsunami has high contents of unstable-form organic matter ???UFOM???\ud
(burned at 300??C), this sludge is considered to be the origin of malodorous gas generation that affects human activities.\ud
Therefore, disposal of the sludge plays an important role in the reconstruction effort. Previously, it is obvious that\ud
granulated coal ash (GCA) comprised of silica (44%), calcium oxide (21%) and aluminum oxide (13%) improves the\ud
organic condition of sewage sludge. For example, the generation of malodorous gases, e.g. hydrogen sulfide and\ud
ammonia, was greatly reduced after mixing GCA with the sewage sludge. In this study, we aim to propose a method\ud
using GCA to disposal the sludge carried by Tsunami. For this purpose, changes in organic conditions and malodorous\ud
gas generation of the sludge after mixing GCA are investigated based on laboratory experiments. In the laboratory\ud
experiments, the sludge was mixed with GCA, and then was burned at 200??C to 600??C (intervals of 100??C) in 4 hours at\ud
each temperature step. Furthermore, other experiments were conducted to measure amounts of gas generated from the\ud
sludge in the absence and the presence of GCA. It was found that ignition behaviors of the sludge with and without\ud
GCA were different, namely, the ignition loss at 300??C of the sludge mixing with GCA was lower than that of the sludge\ud
without mixing GCA. This ensures that organic conditions (e.g. decreases in amounts of UFOM) of the sludge changes\ud
after mixing GCA. Moreover, it was also found that malodorous gases did not generate from the sludge mixing with\ud
GCA, indicating that GCA affects the digestion process of organic matter. It is expected that our proposed method is\ud
also useful for the capitalization of dredged soil and the development of lowland
Magnetooptic properties of self-trapped excitons in cesium halides
A model for the electronic structure of self-trapped excitons in Cs halides is proposed. By applying it, reasonable interpretations were obtained for the magnetic circular polarization (MCP) of the 2 intrinsic emissions in CsI, and for the MCP and EPR in CsBr
Large Polarization Degree of Comet 2P/Encke Continuum Based on Spectropolarimetric Signals During Its 2017 Apparition
Spectropolarimetry is a powerful technique for investigating the physical
properties of gas and solid materials in cometary comae without mutual
contamination, but there have been few spectropolarimetric studies to extract
each component. We attempt to derive the continuum polarization degree of comet
2P/Encke, free from influence of molecular emissions. The target is unique in
that it has an orbit dynamically decoupled from Jupiter like main-belt
asteroids, while ejecting gas and dust like ordinary comets. We observed the
comet using the Higashi-Hiroshima Optical and Near-Infrared Camera attached to
the Cassegrain focus of the 150-cm Kanata telescope on UT 2017 February 21 when
the comet was at the solar phase angle of 75.7 deg. We find that the continuum
polarization degree with respect to the scattering plane is 33.8+/-2.7 % at the
effective wavelength of 0.815 um, which is significantly higher than those of
cometary dust in a high-Pmax group at similar phase angles. Assuming that an
ensemble polarimetric response of 2P/Encke's dust as a function of phase angle
is morphologically similar with those of other comets, its maximum polarization
degree is estimated to > 40 % at the phase angle of ~100 deg. In addition, we
obtain the polarization degrees of the C2 swan bands (0.51-0.56 um), the NH2
alpha bands (0.62-0.69 um) and the CN-red system (0.78-0.94 um) in a range of
3-19 %, which depend on the molecular species and rotational quantum numbers of
each branch. The polarization vector aligns nearly perpendicularly to the
scattering plane with the average of 0.4 deg over a wavelength range of
0.50-0.97 um. From the observational evidence, we conjecture that the large
polarization degree of 2P/Encke would be attributable to a dominance of large
dust particles around the nucleus, which have remained after frequent
perihelion passages near the Sun.Comment: 9 pages, 4 figures, accepted for publication in Astronomy &
Astrophysic
Selective breeding and selection mapping using a novel wild-derived heterogeneous stock of mice revealed two closely-linked loci for tameness
Tameness is a major behavioral factor for domestication, and can be divided into two potential components: motivation to approach humans (active tameness) and reluctance to avoid humans (passive tameness). We identified genetic loci for active tameness through selective breeding, selection mapping, and association analysis. In previous work using laboratory and wild mouse strains, we found that laboratory strains were predominantly selected for passive tameness but not active tameness during their domestication. To identify genetic regions associated with active tameness, we applied selective breeding over 9 generations for contacting, a behavioural parameter strongly associated with active tameness. The prerequisite for successful selective breeding is high genetic variation in the target population, so we established and used a novel resource, wild-derived heterogeneous stock (WHS) mice from eight wild strains. The mice had genetic variations not present in other outbred mouse populations. Selective breeding of the WHS mice increased the contacting level through the generations. Selection mapping was applied to the selected population using a simulation based on a non-selection model and inferred haplotype data derived from single-nucleotide polymorphisms. We found a genomic signature for selection on chromosome 11 containing two closely linked loci
Diode-type Gas Sensors Fabricated with a Titania Film on a Ti Plate and Pd-Pt Electrodes –Effects of Polymer Coating on the Hydrogen-sensing Properties–
H2 responses of a diode-type gas sensor fabricated with a TiO2 film prepared by anodization of a Ti plate and Pd-Pt electrodes (Pd-Pt/TiO2) and the effects of polymer coating on the Pd-Pt/TiO 2 sensor were investigated in this study. The H2 response of the Pd-Pt/TiO2 sensor in dry N2 was larger than that in dry air at 250°C, but the addition of moisture into the atmosphere reduced O2 concentration dependence of H2 response. The responses decreased drastically at lower temperature (50°C), but the responses in N2 were larger than those in air under both dry and wet conditions. The coating of polymer on the Pd-Pt/TiO2 sensor increased the H 2 responses in wet air and N2 and reduced O2 concentration dependence of H2 responses
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