9,563 research outputs found
Effect of deposition conditions and thermal annealing on the charge trapping properties of SiN[sub x] films
The density of charge trapping centers in SiNx:H films deposited by plasma enhanced chemical
vapor deposition is investigated as a function of film stoichiometry and postdeposition annealing
treatments. In the as-deposited films, the defect density is observed to increase with an increasing
N/Si ratio x in the range of 0.89–1.45, and to correlate with the N–H bond density. Following the
annealing in the temperature range of 500– 800 °C, the defect density increases for all N/Si ratios,
with the largest increase observed in the most Si rich samples. However, the defect density always
remains highest in the most N rich films. The better charge storage ability suggests the N rich films
are more suitable for the creation of negatively charged nitride films on solar cells.Financial support from
the Australian Research Council LP0883613 is gratefully
acknowledged
Superradiance Lattice
We show that the timed Dicke states of a collection of three-level atoms can
form a tight-binding lattice in momentum space. This lattice, coined the
superradiance lattice (SL), can be constructed based on electromagnetically
induced transparency (EIT). For a one-dimensional SL, we need the coupling
field of the EIT system to be a standing wave. The detuning between the two
components of the standing wave introduces an effective uniform force in
momentum space. The quantum lattice dynamics, such as Bloch oscillations,
Wannier-Stark ladders, Bloch band collapsing and dynamic localization can be
observed in the SL. The two-dimensional SL provides a flexible platform for
Dirac physics in graphene. The SL can be extended to three and higher
dimensions where no analogous real space lattices exist with new physics
waiting to be explored.Comment: 6pages, 4 figure
Harnack Inequality and Strong Feller Property for Stochastic Fast-Diffusion Equations
This paper presents analogous results for stochastic fast-diffusion
equations. Since the fast-diffusion equation possesses weaker dissipativity
than the porous medium one does, some technical difficulties appear in the
study. As a compensation to the weaker dissipativity condition, a Sobolev-Nash
inequality is assumed for the underlying self-adjoint operator in applications.
Some concrete examples are constructed to illustrate the main results.Comment: to appear in Journal of Mathematical Analysis and Application
SPDE in Hilbert Space with Locally Monotone Coefficients
In this paper we prove the existence and uniqueness of strong solutions for
SPDE in Hilbert space with locally monotone coefficients, which is a
generalization of the classical result of Krylov and Rozovskii for monotone
coefficients. Our main result can be applied to different types of SPDEs such
as stochastic reaction-diffusion equations, stochastic Burgers type equation,
stochastic 2-D Navier-Stokes equation, stochastic -Laplace equation and
stochastic porous media equation with some non-monotone perturbations.Comment: 20 pages, add Remark 3.1 for stochastic Burgers equatio
Regulation of matrix metallo-proteinase expression by extracellular matrix components in cultured hepatic stellate cells
Hepatic stellate cells (HSC) changed their morphology and function including production of matrix metalloproteinases (MMPs) in response to extracellular matrix (ECM) component used as a substratum in culture. We examined in this study the regulatory role of ECM component on expression of MMPs and tissue inhibitor of metalloproteinase (TIMP) in rat HSCs cultured on polystyrene, type I collagen-coated surface, type I collagen gel, or Matrigel, respectively. When cultured on type I collagen gel, HSCs showed the asteroid cell shape and MMP-1 activity, as detected by in situ zymography. Expression of MMP-1 protein and mRNA were examined by using immunofluorescence staining and RT-PCR analysis in HSCs cultured on type I collagen gel. Active form of MMP-2 was detected by gelatin zymography in the conditioned medium of HSCs cultured on type I collagen gel, whereas it was not detected when HSCs were cultured on polystyrene, type I collagen-coated surface, or Matrigel. Increased MMP-2 mRNA was detected by RT-PCR in HSCs cultured on type I collagen gel. Increased MT1-MMP proteins were shown to localize on the cell membrane by using immunofluorescence staining in HSCs cultured on type I collagen gel. Elevated expression of membrane-type matrix metallproteinase-1 (MT1-MMP) mRNA and tissue inhibitor of metalloproteinase-2 (TIMP-2) mRNA was detected by RT-PCR in HSCs cultured on type I collagen-coated surface or type I collagen gel. These results indicate that expression of MMPs and TIMP-2 is regulated by ECM components in cultured HSCs, suggesting an important role of HSCs in the remodeling of liver tissue
Bis(μ-3,5-dinitrobenzoato-κ2 O 1:O 1′)bis(μ-3,5-dinitrobenzoato)-κ3 O 1,O 1′:O 1;κ3 O 1:O 1,O 1′-bis[(3,5-dinitrobenzoato-κ2 O 1,O 1′)(1,10-phenanthroline-κ2 N,N)dysprosium(III)]
In the binuclear title complex, [Dy2(C7H3N2O6)6(C12H8N2)2], the DyIII ions exhibit a distorted monocapped square-antiprismatic geometry and are coordinated by seven O atoms of four 3,5-dinitrobenzoate (DNBA) anions and two N atoms of a phenanthroline ligand. The carboxylate groups of the DNBA anions exhibit three coordination modes: bidentate chelating, bidentate chelating–bridging and tridentate chelating–bridging. The center of the molecule is located on a crystallographic center of inversion
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