826 research outputs found
Comment on "Band structure engineering of graphene by strain: First-principles calculations"
In their first-principles calculations of the electronic band structure of
graphene under uniaxial strain, Gui, Li, and Zhong [Phys. Rev. B \textbf{78},
075435 (2008)] have found opening of band gaps at the Fermi level. This finding
is in conflict with the tight-binding description of graphene which is closed
gap for small strains. In this Comment, we present first-principles
calculations which refute the claim that strain opens band gaps in graphene.Comment: published versio
Energy gap opening in submonolayer lithium on graphene: Local density functional and tight-binding calculations
The adsorption of an alkali-metal submonolayer on graphene occupying every
third hexagon of the honeycomb lattice in a commensurate
arrangement induces an energy gap in the
spectrum of graphene. To exemplify this type of band gap, we present \textit{ab
initio} density functional theory calculations of the electronic band structure
of CLi. An examination of the lattice geometry of the compound system shows
the possibility that the nearest-neighbor hopping amplitudes have alternating
values constructed in a Kekul\'e-type structure. The band structure of the
textured tight-binding model is calculated and shown to reproduce the expected
band gap as well as other characteristic degeneracy removals in the spectrum of
graphene induced by lithium adsorption. More generally we also deduce the
possibility of energy gap opening in periodic metal on graphene compounds
CM if is a multiple of 3.Comment: 7 pages, 5 figures, published versio
Numerical simulation of the stochastic dynamics of inclusions in biomembranes in presence of surface tension
The stochastic dynamics of inclusions in a randomly fluctuating biomembrane
is simulated. These inclusions can represent the embedded proteins and the
external particles arriving at a cell membrane. The energetics of the
biomembrane is modelled via the Canham-Helfrich Hamiltonian. The contributions
of both the bending elastic-curvature energy and the surface tension of the
biomembrane are taken into account. The biomembrane is treated as a
two-dimensional sheet whose height variations from a reference frame is treated
as a stochastic Wiener process. The lateral diffusion parameter associated with
this Wiener process coupled with the longitudinal diffusion parameter obtained
from the standard Einsteinian diffusion theory completely determine the
stochastic motion of the inclusions. It is shown that the presence of surface
tension significantly affects the overall dynamics of the inclusions,
particularly the rate of capture of the external inclusions, such as drug
particles, at the site of the embedded inclusions, such as the embedded
proteins.Comment: 17 pages, 4 figures, to appear in physica
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Molecular dynamics simulation of observed c(4x4) and c(4x3) C60 alignments on the Si(100) reconstructed surface.
We have implemented a large-scale classical molecular dynamics simulation at constant temperature to provide a theoretical insight into the results of a recently performed experiment on the monolayer and multi-layer formations of molecular films on the Si(100) reconstructed dimerized surface. Our simulation has successfully reproduced all of the morphologies observed on the monolayer film by this experiment. We have obtained the formation of both c(4 4) and c(4 3) structures of the molecules and have also obtained phase transitions of the former into the latter
Thermal conductivity of deformed carbon nanotubes
We investigate the thermal conductivity of four types of deformed carbon
nanotubes by using the nonequilibrium molecular dynamics method. It is reported
that various deformations have different influence on the thermal properties of
carbon nanotubes. For the bending carbon nanotubes, the thermal conductivity is
independent on the bending angle. However, the thermal conductivity increases
lightly with XY-distortion and decreases rapidly with Z-distortion. The thermal
conductivity does not change with the screw ratio before the breaking of carbon
nanotubes but decreases sharply after the critical screw ratio.Comment: 6figure
Independent and social living skills training for people with Schizophrenia in Iran: A randomized controlled trial
Objectives: Schizophrenia is responsible for a significant proportion of burden of mental diseases in Iran. Lack of a follow-up system has resulted in the repeated hospitalizations. In this study it is hypothesized that standardized living skills training delivered to participants with schizophrenia in outpatient and inpatient centers can be effective compared to a control group (with occupational therapy) in reducing psychopathology severity and increasing quality of life. Methods: This is a multi-centered parallel group randomized controlled trial in Iran and it is singleblinded. Eligible participants are randomly allocated into two groups in a 1:1 ratio. Participants are assigned by stratified balanced block randomization method. The trial is conducted in the cities of Tehran and Mashhad. Its aim is to recruit 160 clients with schizophrenia. The intervention for the experimental group is social living skills training. The intervention for the control group is occupational therapy. The intervention for both groups is conducted in 90 to 120-minute group sessions. The primary outcome of the study would be a decrease in psychopathology severity, an improvement in participants' quality of life, and reduction in family burden will be followed for 6 months. Discussion: This paper presents a protocol for a randomized controlled trial of independent and social living skills training intervention delivered to participants with schizophrenia. If this intervention is effective, it could be scaled up to be developing for policymaking and improving outcomes for schizophrenic participants and their families in Iran
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