1,996 research outputs found
On the r-matrix structure of the hyperbolic BC(n) Sutherland model
Working in a symplectic reduction framework, we construct a dynamical
r-matrix for the classical hyperbolic BC(n) Sutherland model with three
independent coupling constants. We also examine the Lax representation of the
dynamics and its equivalence with the Hamiltonian equation of motion.Comment: 20 page
μ-crystallin, a NADPH-dependent T-3-binding protein in cytosol
http://www.elsevier.com/wps/find/journaldescription.cws_home/505783/description#description | http://www.elsevier.com/wps/find/journaldescription.cws_home/505783/description#descriptionArticleTRENDS IN ENDOCRINOLOGY AND METABOLISM. 18(7): 286-289journal articl
Evaluation of the hydrogen solubility and diffusivity in proton-conducting oxides by converting the PSL values of a tritium imaging plate
Proton-conducting oxides have potential applications in hydrogen sensors,
hydrogen pumps, and other electrochemical devices including the tritium
purification and recovery systems of nuclear fusion reactors. Although the
distribution of hydrogen (H) in such oxide materials is an important aspect,
its precise measurement is difficult. In the present study, the hydrogen
solubility and diffusivity behavior of BaZr0.9Y0.1O2.95 (BZY),
BaZr0.955Y0.03Co0.015O2.97 (BZYC), and CaZr0.9In0.1O2.95 (CZI) were studied
using tritiated heavy water vapor i.e., DTO (~2 kPa, tritium (T) = 0.1%) by
converting the photostimulated luminescence (PSL) values of the imaging plate
(IP). The samples were exposed to DTO vapor at 673 K for 2 h or at 873 K for 1
h. The disc-shaped oxide specimens (diameter ~7.5 mm; thickness ~2.3 mm;
theoretical density (TD) > 98 %) were prepared by conventional powder
metallurgy. The IP images of the specimen surfaces of all the three materials
T-exposed revealed that BZY showed the most uniform T distribution with the
highest tritium activity. The cross-sectional T concentration profiles of the
cut specimens showed that T diffused deeper into BZY and BZYC than into CZI.
The hydrogen solubility and diffusivity in the CZI specimen were lower than
that in the BZY and BZYC specimens. This suggested that barium zirconates were
more favorable proton conductors than calcium zirconates.Comment: 19 pages, 12 figure
Critical enhancement of thermopower in a chemically tuned polar semimetal MoTe
Ferroelectrics with spontaneous electric polarization play an essential role
in today's device engineering, such as capacitors and memories. Their physical
properties are further enriched by suppressing the long-range polar order, as
is exemplified by quantum paraelectrics with giant piezoelectric and dielectric
responses at low temperatures. Likewise in metals, a polar lattice distortion
has been theoretically predicted to give rise to various unusual physical
properties. So far, however, a "ferroelectric"-like transition in metals has
seldom been controlled and hence its possible impacts on transport phenomena
remain unexplored. Here we report the discovery of anomalous enhancement of
thermopower near the critical region between the polar and nonpolar metallic
phases in 1T'-MoNbTe with a chemically tunable polar
transition. It is unveiled from the first-principles calculations and
magnetotransport measurements that charge transport with strongly
energy-dependent scattering rate critically evolves towards the boundary to the
nonpolar phase, resulting in large cryogenic thermopower. Such a significant
influence of the structural instability on transport phenomena might arise from
the fluctuating or heterogeneous polar metallic states, which would pave a
novel route to improving thermoelectric efficiency.Comment: 26 pages, 4 figure
Ferromagnetism in a Hubbard model for an atomic quantum wire: a realization of flat-band magnetism from even-membered rings
We have examined a Hubbard model on a chain of squares, which was proposed by
Yajima et al as a model of an atomic quantum wire As/Si(100), to show that the
flat-band ferromagnetism according to a kind of Mielke-Tasaki mechanism should
be realized for an appropriate band filling in such a non-frustrated lattice.
Reflecting the fact that the flat band is not a bottom one, the ferromagnetism
vanishes, rather than intensified, as the Hubbard U is increased. The exact
diagonalization method is used to show that the critical value of U is in a
realistic range. We also discussed the robustness of the magnetism against the
degradation of the flatness of the band.Comment: misleading terms and expressions are corrected, 4 pages, RevTex, 5
figures in Postscript, to be published in Phys. Rev. B (rapid communication
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