7,933 research outputs found
Ab-initio density functional studies of stepped TaC surfaces
We report on density functional total energy calculations of the step
formation and interaction energies for vicinal TaC(001) surfaces. Our
calculations show that double and triple-height steps are favored over
single-height steps for a given vicinal orientation, which is in agreement with
recent experimental observations. We provide a description of steps in terms of
atomic displacements and charge localization and predict an experimentally
observable rumpled structure of the step-edges, where the Ta atoms undergo
larger displacements compared to the C atoms.Comment: 4 pages, 4 figure
Lambda polarization in pp -> p\Lambda K^+ \pi^+\pi^-\pi^+\pi^-
We show that there is a correlation between the invariant mass of the
produced \Lambda K^+, \Lambda K^+\pi^+\pi^- or \Lambda K^+ \pi^+\pi^-\pi^+\pi^-
system in the exclusive reaction pp\to p\Lambda K^+\pi^+\pi^-\pi^+\pi^- and the
longitudinal or transverse momentum of . Together with the
longitudinal and transverse momentum dependence of Lambda polarization observed
in inclusive reactions, such a correlation implies a dependence of Lambda
polarization on these invariant masses. The qualitative features of this
dependence are consistent with the recent observation by E766 collaboration at
BNL. A quantitative estimation has been made using an event generator for
collisions. A detailed comparison with the data is made.Comment: 10 pages with 3 figures, submitted to J. Phys.
Medium mass fragments production due to momentum dependent interactions
The role of system size and momentum dependent effects are analyzed in
multifragmenation by simulating symmetric reactions of Ca+Ca, Ni+Ni, Nb+Nb,
Xe+Xe, Er+Er, Au+Au, and U+U at incident energies between 50 MeV/nucleon and
1000 MeV/nucleon and over full impact parameter zones. Our detailed study
reveals that there exist a system size dependence when reaction is simulated
with momentum dependent interactions. This dependence exhibits a mass power law
behavior.Comment: 5 figure
Azimuthal and single spin asymmetry in deep-inelastic lepton-nucleon scattering
We derive a general framework for describing semi-inclusive deep-inelastic
lepton-nucleon scattering in terms of the unintegrated parton distributions and
other higher twist parton correlations. Such a framework provides a consistent
approach to the calculation of inclusive and semi-inclusive cross sections
including higher twist effects. As an example, we calculate the azimuthal
asymmetries to the order of 1/Q in semi-inclusive process with transversely
polarized target. A non-vanishing single-spin asymmetry in the ``triggered
inclusive process'' is predicted to be 1/Q suppressed with a part of the
coefficient related to a moment of the Sivers function.Comment: 9 pages, 1 figur
Direct Measurement of Piezoelectric Response around Ferroelectric Domain Walls in Crystals with Engineered Domain Configuration
We report the first investigation of the piezoelectric response on a
nanoscale in the poled ferroelectric crystals with engineered configuration of
domains. Piezoresponse force microscopy of tetragonal 0.63PMN-0.37PT
relaxor-based ferroelectric crystals reviled that the d33 piezoelectric
coefficient is significantly reduced within the distance of about 1 um from the
uncharged engineered domain wall. This finding is essential for understanding
the mechanisms of the giant piezoresponse in relaxor-based crystals and for
designing new piezoelectric materials
Assembled matrix distance metric for 2DPCA-based face and palmprint recognition
Author name used in this publication: David ZhangBiometrics Research Centre, Department of ComputingVersion of RecordPublishe
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