7,958 research outputs found
Comment on "Phonon Spectrum and Dynamical Stability of a Dilute Quantum Degenerate Bose-Fermi Mixture
We show that the conclusions of a recent PRL by Pu et al is incorrect.Comment: late
Magnetic Properties of a Superconductor with no Inversion Symmetry
We study the magnetic properties of a superconductor in a crystal without symmetry, in particular how the lack of this symmetry exhibits itself.
We show that, though the penetration depth itself shows no such effect, for
suitable orientation of magnetic field, there is a magnetic field discontinuity
at the interface which shows this absence of symmetry. The magnetic field
profile of a vortex in the plane is shown to be identical to that of an
ordinary anisotropic superconductor except for a shift in the direction by
(see errata). For a vortex along , there is an
induced magnetization along the radial direction.Comment: J. Low Temp. Physics, 140, 67 (2005); with Errat
Phase diagrams of a p-Wave superconductor inside a mesoscopic disc-shaped sample
We study the finite-size and boundary effects on a time-reversal-symmetry
breaking p-wave superconducting state in a mesoscopic disc geometry using
Ginzburg-Landau theory. We show that, for a large parameter range, the system
exhibits multiple phase transitions. The superconducting transition from the
normal state can also be reentrant as a function of external magnetic field.Comment: Revised version published in Physical Review
Further investigation of a finite difference procedure for analyzing the transonic flow about harmonically oscillating airfoils and wings
Analytical and empirical studies of a finite difference method for the solution of the transonic flow about harmonically oscillating wings and airfoils are presented. The procedure is based on separating the velocity potential into steady and unsteady parts and linearizing the resulting unsteady equations for small disturbances. The steady velocity potential is obtained first from the well-known nonlinear equation for steady transonic flow. The unsteady velocity potential is then obtained from a linear differential equation in complex form with spatially varying coefficients. Since sinusoidal motion is assumed, the unsteady equation is independent of time. An out-of-core direct solution procedure was developed and applied to two-dimensional sections. Results are presented for a section of vanishing thickness in subsonic flow and an NACA 64A006 airfoil in supersonic flow. Good correlation is obtained in the first case at values of Mach number and reduced frequency of direct interest in flutter analyses. Reasonable results are obtained in the second case. Comparisons of two-dimensional finite difference solutions with exact analytic solutions indicate that the accuracy of the difference solution is dependent on the boundary conditions used on the outer boundaries. Homogeneous boundary conditions on the mesh edges that yield complex eigenvalues give the most accurate finite difference solutions. The plane outgoing wave boundary conditions meet these requirements
FORTRAN subroutines for out-of-core solutions of large complex linear systems
The design and usage of two main subprograms using direct methods to solve large linear complex systems, of the form Ax = b, whose coeffficient matrices are too large to be stored in core are described. The first main subprogram is for systems whose coefficient matrices are of a particular sparse structure, namely, the matrix A can be written in the form B + D, where B is a block-banded system, and D has only a few columns of nonzeros. Key elements of the algorithms used in the subprograms include: the data structure, the strategy for preserving numerical stability, the adaptability of the algorithms for dense systems as well as for block-profile systems
Point defect concentrations in metastable Fe-C alloys
Point defect species and concentrations in metastable Fe-C alloys are
determined using density functional theory and a constrained free-energy
functional. Carbon interstitials dominate unless iron vacancies are in
significant excess, whereas excess carbon causes greatly enhances vacancy
concentration. Our predictions are amenable to experimental verification; they
provide a baseline for rationalizing complex microstructures known in hardened
and tempered steels, and by extension other technological materials created by
or subjected to extreme environments
Inert-states of spin-5 and spin-6 Bose-Einstein condensates
In this paper we consider spinor Bose-Einstein condensates with spin f=5 and
f=6 in the presence and absence of external magnetic field at the mean field
level. We calculate all of so-called inert-states of these systems.
Inert-states are very unique class of stationary states because they remain
stationary while Hamiltonian parameters change. Their existence comes from
Michel's theorem. For illustration of symmetry properties of the inert-states
we use method that allows classification of the systems as a polyhedron with 2f
vertices proposed by R. Barnett et al., Phys. Rev. Lett. 97, 180412 (2006).Comment: 19 pages, 4 figure
The Contribution of Population Health and Demographic Change to Economic Growth in China and India
We find that a cross-country model of economic growth successfully tracks the growth takeoffs in China and India. The major drivers of the predicted takeoffs are improved health, increased openness to trade, and a rising labor force-to-population ratio due to fertility decline. We also explore the effect of the reallocation of labor from low-productivity agriculture to the higher productivity industry and service sectors. Including the money value of longevity improvements in a measure of full income reduces the gap between the magnitude of China's takeoff relative to India's due to the relative stagnation in life expectancy in China since 1980.aging, health, retirement
Pairing Symmetry in the Anisotropic Fermi Superfluid under p-wave Feshbach Resonance
The anisotropic Fermi superfluid of ultra-cold Fermi atoms under the p-wave
Feshbach resonance is studied theoretically. The pairing symmetry of the ground
state is determined by the strength of the atom-atom magnetic dipole
interaction. It is for a strong dipole interaction; while it becomes , up to a rotation about z, for a weak one (Here < 1 is a
numerical coefficient). By changing the external magnetic field or the atomic
gas density, a phase transition between these two states can be driven. We
discuss how the pairing symmetry of the ground state can be determined in the
time-of-flight experiments.Comment: 12 pages, 7 figure
Mad and Misleading: Incidental Anger Promotes Deception
Emotions influence ethical behavior. Across four studies, we demonstrate that incidental anger, anger triggered by an unrelated situation, promotes the use of deception. In Study 1, participants who felt incidental anger were more likely to deceive their counterpart than those who felt neutral emotion. In Study 2, we demonstrate that empathy mediates the relationship between anger and deception. In Study 3, we contrast anger with another negative-valence emotion, sadness. We find that participants who felt incidental anger were more likely to use deception than were participants who felt incidental sadness or neutral emotion. In Study 4, we show that incentives moderate the relationship between anger and deception. Collectively, our work reveals that incidental anger promotes unethical behavior because angry people become less empathetic when pursuing their self-interest
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