10,119 research outputs found
Anomalous Hall effect in L10-MnAl films with controllable orbital two-channel Kondo effect
The anomalous Hall effect (AHE) in strongly disordered magnetic systems has
been buried in persistent confusion despite its long history. We report the AHE
in perpendicularly magnetized L10-MnAl epitaxial films with variable orbital
two-channel Kondo (2CK) effect arising from the strong coupling of conduction
electrons and the structural disorders of two-level systems. The AHE is
observed to excellently scale with pAH/f=a0pxx0+bpxx2 at high temperatures
where phonon scattering prevails. In contrast, significant deviation occurs at
low temperatures where the orbital 2CK effect becomes important, suggesting a
negative AHE contribution. The deviation of the scaling agrees with the orbital
2CK effect in the breakdown temperatures and deviation magnitudes
Dynamics of Vibrated Granular Monolayers
We study statistical properties of vibrated granular monolayers using
molecular dynamics simulations. We show that at high excitation strengths, the
system is in a gas state, particle motion is isotropic, and the velocity
distributions are Gaussian. As the vibration strength is lowered the system's
dimensionality is reduced from three to two. Below a critical excitation
strength, a gas-cluster phase occurs, and the velocity distribution becomes
bimodal. In this phase, the system consists of clusters of immobile particles
arranged in close-packed hexagonal arrays, and gas particles whose energy
equals the first excited state of an isolated particle on a vibrated plate.Comment: 4 pages, 6 figs, revte
Evolution of In-Plane Magnetic Anisotropy In Sputtered FeTaN/TaN/FeTaN Sandwich Films
FeTaN/TaN/FeTaN sandwich films, FeTaN/TaN and TaN/FeTaN bilayers were
synthesized by using RF magnetron sputtering. The magnetic properties,
crystalline structures, microstructures and surface morphologies of the
as-deposited samples were characterized using angle-resolved M-H loop tracer,
VSM, XRD, TEM, AES and AFM. An evolution of the in-plane anisotropy was
observed with the changing thickness of the nonmagnetic TaN interlayer in the
FeTaN/TaN/FeTaN sandwiches, such as the easy-hard axis switching and the
appearing of biaxial anisotropy. It is ascribed to three possible mechanisms,
which are interlayer magnetic coupling, stress, and interface roughness,
respectively. Interlayer coupling and stress anisotropies may be the major
reasons to cause the easy-hard axis switching in the sandwiches. Whereas,
magnetostatic and interface anisotropies may be the major reasons to cause
biaxial anisotropy in the sandwiches, in which magnetostatic anisotropy is the
dominant one.Comment: 6 pages, 3 figure
Optical spectroscopy study of Nd(O,F)BiS2 single crystals
We present an optical spectroscopy study on F-substituted NdOBiS
superconducting single crystals grown using KCl/LiCl flux method. The
measurement reveals a simple metallic response with a relatively low screened
plasma edge near 5000 \cm. The plasma frequency is estimated to be 2.1 eV,
which is much smaller than the value expected from the first-principles
calculations for an electron doping level of x=0.5, but very close to the value
based on a doping level of 7 of itinerant electrons per Bi site as
determined by ARPES experiment. The energy scales of the interband transitions
are also well reproduced by the first-principles calculations. The results
suggest an absence of correlation effect in the compound, which essentially
rules out the exotic pairing mechanism for superconductivity or scenario based
on the strong electronic correlation effect. The study also reveals that the
system is far from a CDW instability as being widely discussed for a doping
level of x=0.5.Comment: 5 pages, 5 figure
Galilean invariance of lattice Boltzmann models
It is well-known that the original lattice Boltzmann (LB) equation deviates
from the Navier-Stokes equations due to an unphysical velocity dependent
viscosity. This unphysical dependency violates the Galilean invariance and
limits the validation domain of the LB method to near incompressible flows. As
previously shown, recovery of correct transport phenomena in kinetic equations
depends on the higher hydrodynamic moments. In this Letter, we give specific
criteria for recovery of various transport coefficients. The Galilean
invariance of a general class of LB models is demonstrated via numerical
experiments
High sensitivity nanoparticle detection using optical microcavities
We demonstrate a highly sensitive nanoparticle and virus detection method by using a thermal-stabilized reference interferometer in conjunction with an ultrahigh-Q microcavity. Sensitivity is sufficient to resolve shifts caused by binding of individual nanobeads in solution down to a record radius of 12.5 nm, a size approaching that of single protein molecules. A histogram of wavelength shift versus nanoparticle radius shows that particle size can be inferred from shift maxima. Additionally, the signal-to-noise ratio for detection of Influenza A virus is enhanced to 38:1 from the previously reported 3:1. The method does not use feedback stabilization of the probe laser. It is also observed that the conjunction of particle-induced backscatter and optical-path-induced shifts can be used to enhance detection signal-to-noise
Truth-telling to the patient, family, and the sexual partner: a rights approach to the role of healthcare providers in adult HIV disclosure in China.
Patients' rights are central in today's legislation and social policies related to health care, including HIV care, in not only Western countries but around the world. However, given obvious socio-cultural differences it is often asked how or to what extent patients' rights should be respected in non-Western societies such as China. In this paper, it is argued that the patients' rights framework is compatible with Chinese culture, and that from the perspective of contemporary patient rights healthcare providers have a duty to disclose truthfully the diagnosis and prognosis to their patients, that the Chinese cultural practice of involving families in care should - with consent from the patient - be promoted out of respect for patients' rights and well-being, and that healthcare providers should be prepared to address the issue of disclosing a patient's HIV status to sexual partner(s). Legally, the provider should be permitted to disclose without consent from the patient but not obliged to in all cases. The decision to do this should be taken with trained sensitivity to a range of ethically relevant considerations. Post-disclosure counseling or psychological support should be in place to address the concerns of potentially adverse consequences of provider-initiated disclosure and to maximize the psychosocial and medical benefits of the disclosure. There is an urgent need for healthcare providers to receive training in ethics and disclosure skills. This paper concludes also with some suggestions for improving the centerpiece Chinese legislation, State Council's "Regulations on AIDS Prevention and Control" (2006), to further safeguard the rights and well-being of HIV patients
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