232 research outputs found
Maternal lineages in polyploid wheat species inferred from organeller DNA fingerprinting
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134958.pdf (publisher's version ) (Closed access)Health promoting messages can be framed in terms of the gains that are associated with healthy behaviour, or the losses that are associated with unhealthy behaviour. In this study, we examined the influence of self-efficacy to quit smoking on the effects of gain framed and loss framed anti-smoking messages in a randomized controlled trial among 539 adult smokers. Participants with a high self-efficacy to quit smoking reported higher levels of motivation to quit smoking after receiving a loss framed message than after receiving a gain framed message or no message. For these participants receiving a gain framed message did not result in a higher motivation to quit smoking than receiving no message. For participants with a low self-efficacy to quit smoking there were no differences in motivation to quit smoking between the gain framed message condition, loss framed message condition and control condition. Our results suggest that self-efficacy can moderate the effects of message framing on persuasion
Angular dependence of novel magnetic quantum oscillations in a quasi-two-dimensional multiband Fermi liquid with impurities
The semiclassical Lifshitz-Kosevich-type description is given for the angular
dependence of quantum oscillations with combination frequencies in a multiband
quasi-two-dimensional Fermi liquid with a constant number of electrons. The
analytical expressions are found for the Dingle, thermal, spin, and amplitude
(Yamaji) reduction factors of the novel combination harmonics, where the latter
two strongly oscillate with the direction of the field. At the "magic" angles
those factors reduce to the purely two-dimensional expressions given earlier.
The combination harmonics are suppressed in the presence of the non-quantized
("background") states, and they decay exponentially faster with temperature
and/or disorder compared to the standard harmonics, providing an additional
tool for electronic structure determination. The theory is applied to
SrRuO.Comment: 5 pages, 2 figures, minor typos correcte
Spin triplet superconductivity with line nodes in Sr2RuO4
Several possible odd-parity states are listed up group-theoretically and
examined in light of recent experiments on SrRuO. Those include some of
the -wave pairing states, {\mib d}({\mib k})\propto{\hat{\mib z}}
k_xk_y(k_x + {\rm i}k_y) and {\hat{\mib z}} (k_x^2-k_y^2)(k_x + {\rm i}k_y)
and other {\hat{\mib z}} (k_x + {\rm i}k_y)\cos ck_z ( is the -axis
lattice constant) as most plausible candidates. These are time-reversal
symmetry broken states and have line nodes running either vertically (the
former two) or horizontally (the latter), consistent with experiments.
Characterizations of these states and other possibilities are given.Comment: 4 pages, no figure
Laminar supersonic sphere wake unstable bifurcations
The laminar sphere unstable bifurcations are sought at a Mach number of M∞ = 1.2. Global stability performed on steady axisymmetric base flows determines the regular bifurcation critical Reynolds number at Rereg cr = 650, identifying a steady planar-symmetric mode to cause the loss of the wake axisymmetry. When global stability is performed on steady planar-symmetric base flows, a Hopf bifurcation is found at ReHopf cr = 875 and an oscillatory planar-symmetric mode is temporally amplified. Despite some differences due to highly compressible effects, the supersonic unstable bifurcations present remarkably similar characteristics to their incompressible counterparts, indicating a robust laminar wake behavior over a large range of flow speeds. A new bifurcation for steady planar-symmetric base flow solutions is found above Re > 1000, caused by an anti-symmetric mode consisting of a 90○ rotation of the dominant mode. To investigate this reflectional symmetry breaking bifurcation in the nonlinear framework, unsteady nonlinear calculations are carried out up to Re = 1300 and dynamic mode decomposition (DMD) based on the combination of input data low-dimensionalization and compressive sensing is used. While the DMD analysis confirms dominance and correspondence in terms of modal spatial distribution with respect to the global stability mode responsible for the Hopf bifurcation, no reflectional symmetry breaking DMD modes were found, asserting that the reflectional symmetry breaking instability is not observable in the nonlinear dynamics. The increased complexity of the wake dynamics at Re = 1300 can be instead explained by nonlinear interactions that suggest the low-frequency unsteadiness to be linked to the destabilization of the hairpin vortex shedding limit cycle.CNE
Cyclotron Resonance in the Layered Perovskite Superconductor Sr2RuO4
We have measured the cyclotron masses in Sr2RuO4 through the observation of
periodic-orbit-resonances - a magnetic resonance technique closely related to
cyclotron resonance. We obtain values for the alpha, beta and gamma Fermi
surfaces of (4.33+/-0.05)me, (5.81+/-0.03)me and (9.71+/-0.11)me respectively.
The appreciable differences between these results and those obtained from de
Haas- van Alphen measurements are attributable to strong electron-electron
interactions in this system. Our findings appear to be consistent with
predictions for a strongly interacting Fermi liquid; indeed, semi-quantitative
agreement is obtained for the electron pockets beta and gamma.Comment: 4 pages + 3 figure
Cyclotron resonance in the layered perovskite superconductor Sr2RuO4
We report a detailed study of the magnetic-field-orientation dependence of
the millimetre-wave magnetoconductivity of the superconductor Sr2RuO4 We find
two harmonic series of cyclotron resonances. We assign the first, corresponding
to a quasiparticle mass of , where is the
free-electron mass, to the Fermi-surface section. We assign the second
series, which contains only odd harmonics, to cyclotron resonance of the
Fermi-surface section, yielding a quasiparticle mass of . A third, single cyclotron resonance, corresponding to a
quasiparticle mass of , is attributed to the
Fermi-surface section. In addition, we find a very strong absorption mode in
the presence of a magnetic field component parallel to the
quasi-two-dimensional planes of the sample. Its dependence on the orientation
of the magnetic field cannot be described in the context of conventional
cyclotron resonance, and the origin of this mode is not yet clear.Comment: Submitted to J. Phys. Cond. Ma
Unrestricted Hartree-Fock Analysis of SrCaRuO
We investigated the electronic and magnetic structure of
SrCaRuO () on the basis of the
double-layered three-dimensional multiband Hubbard model with spin-orbit
interaction. In our model, lattice distortion is implemented as the modulation
of transfer integrals or a crystal field. The most stable states are estimated
within the unrestricted Hartree-Fock approximation, in which the colinear spin
configurations with five different spin-quantization axes are adopted as
candidates. The obtained spin structures for some particular lattice
distortions are consistent with the neutron diffraction results for
CaRuO. Also, some magnetic phase transitions can occur due to
changes in lattice distortion. These results facilitate the comprehensive
understanding of the phase diagram of SrCaRuO.Comment: 16 pages, 7 figure
Interface superconductivity in the eutectic Sr2RuO4-Ru: 3-K phase of Sr2RuO4
The eutectic system Sr2RuO4-Ru is referred to as the 3-K phase of the
spin-triplet supeconductor Sr2RuO4 because of its enhanced superconducting
transition temperature Tc of ~3 K. We have investigated the field-temperature
(H-T) phase diagram of the 3-K phase for fields parallel and perpendicular to
the ab-plane of Sr2RuO4, using out-of-plane resistivity measurements. We have
found an upturn curvature in the Hc2(T) curve for H // c, and a rather gradual
temperature dependence of Hc2 close to Tc for both H // ab and H // c. We have
also investigated the dependence of Hc2 on the angle between the field and the
ab-plane at several temperatures. Fitting the Ginzburg-Landau effective-mass
model apparently fails to reproduce the angle dependence, particularly near H
// c and at low temperatures. We propose that all of these charecteric features
can be explained, at least in a qualitative fashion, on the basis of a theory
by Sigrist and Monien that assumes surface superconductivity with a
two-component order parameter occurring at the interface between Sr2RuO4 and Ru
inclusions. This provides evidence of the chiral state postulated for the 1.5-K
phase by several experiments.Comment: 7 pages and 5 figs; accepted for publication in Phys. Rev.
Thermodynamic evidence for broken fourfold rotational symmetry in the hidden-order phase of URu2Si2
Despite more than a quarter century of research, the nature of the
second-order phase transition in the heavy-fermion metal URuSi remains
enigmatic. The key question is which symmetry is being broken below this
"hidden order" transition. We review the recent progress on this issue,
particularly focusing on the thermodynamic evidence from very sensitive
micro-cantilever magnetic torque measurements that the fourfold rotational
symmetry of the underlying tetragonal crystal is broken. The angle dependence
of the torque under in-plane field rotation exhibits the twofold oscillation
term, which sets in just below the transition temperature. This observation
restricts the symmetry of the hidden order parameter to the - or
-type, depending on whether the time reversal symmetry is preserved or
not.Comment: 7 pages, 5 figures, brief review article for Physica C Special Issue
on Stripes and Electronic Liquid Crystals in Strongly Correlated Systems,
updated references and added some discussio
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