109,676 research outputs found
Electrostatic forces on charged surfaces of bilayer lipid membranes
Simulating protein-membrane interactions is an important and dynamic area of
research. A proper definition of electrostatic forces on membrane surfaces is
necessary for developing electromechanical models of protein-membrane
interactions. Here we modeled the bilayer membrane as a continuum with general
continuous distributions of lipids charges on membrane surfaces. A new
electrostatic potential energy functional was then defined for this solvated
protein-membrane system. We investigated the geometrical transformation
properties of the membrane surfaces under a smooth velocity field. These
properties allows us to apply the Hadamard-Zolesio structure theorem, and the
electrostatic forces on membrane surfaces can be computed as the shape
derivative of the electrostatic energy functional
Effect of Dzyaloshinskii Moriya interaction on magnetic vortex
The effect of the Dzyaloshinskii Moriya interaction on the vortex in magnetic
microdisk was investigated by micro magnetic simulation based on the Landau
Lifshitz Gilbert equation. Our results show that the DM interaction modifies
the size of the vortex core, and also induces an out of plane magnetization
component at the edge and inside the disk. The DM interaction can destabilizes
one vortex handedness, generate a bias field to the vortex core and couple the
vortex polarity and chirality. This DM-interaction-induced coupling can
therefore provide a new way to control vortex polarity and chirality
Genetic Exponentially Fitted Method for Solving Multi-dimensional Drift-diffusion Equations
A general approach was proposed in this article to develop high-order
exponentially fitted basis functions for finite element approximations of
multi-dimensional drift-diffusion equations for modeling biomolecular
electrodiffusion processes. Such methods are highly desirable for achieving
numerical stability and efficiency. We found that by utilizing the one-one
correspondence between continuous piecewise polynomial space of degree
and the divergence-free vector space of degree , one can construct
high-order 2-D exponentially fitted basis functions that are strictly
interpolative at a selected node set but are discontinuous on edges in general,
spanning nonconforming finite element spaces. First order convergence was
proved for the methods constructed from divergence-free Raviart-Thomas space
at two different node set
Scaling of nuclear modification factors for hadrons and light nuclei
The number of constituent quarks (NCQ-) scaling of hadrons and the number of
constituent nucleons (NCN-) scaling of light nuclei are proposed for nuclear
modification factors () of hadrons and light nuclei, respectively,
according to the experimental investigations in relativistic heavy-ion
collisions. Based on coalescence mechanism the scalings are performed for pions
and protons in quark level, and light nuclei and He for
nucleonic level, respectively, formed in Au + Au and Pb + Pb collisions and
nice scaling behaviour emerges. NCQ or NCN scaling law of can be
respectively taken as a probe for quark or nucleon coalescence mechanism for
the formation of hadron or light nuclei in relativistic heavy-ion collisions.Comment: 6 pages, 6 figure
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