567 research outputs found
Image of Veselago lens based upon two-dimensional photonic crystal with triangular lattice
The construction of the multi-focal Veselago lens predicted earlier is
proposed on the basis of a uniaxial photonic crystal consisting of cylindrical
air holes in silicon that make a triangular lattice in a plane perpendicular to
the axis of the crystal. The object and image are in air. The period of the
crystal should be to work at the wavelength .
The lens does not provide superlensing but the half-width of the image is
. The lens is shown to have wave guiding properties depending on
the substrate material.Comment: 15 pages, 10 figure
Modeling cancer metabolism on a genome scale
Cancer cells have fundamentally altered cellular metabolism that is associated with their tumorigenicity and malignancy. In addition to the widely studied Warburg effect, several new key metabolic alterations in cancer have been established over the last decade, leading to the recognition that altered tumor metabolism is one of the hallmarks of cancer. Deciphering the full scope and functional implications of the dysregulated metabolism in cancer requires both the advancement of a variety of omics measurements and the advancement of computational approaches for the analysis and contextualization of the accumulated data. Encouragingly, while the metabolic network is highly interconnected and complex, it is at the same time probably the best characterized cellular network. Following, this review discusses the challenges that genome‐scale modeling of cancer metabolism has been facing. We survey several recent studies demonstrating the first strides that have been done, testifying to the value of this approach in portraying a network‐level view of the cancer metabolism and in identifying novel drug targets and biomarkers. Finally, we outline a few new steps that may further advance this field
Divergence of Dipole Sums and the Nature of Non-Lorentzian Exponentially Narrow Resonances in One-Dimensional Periodic Arrays of Nanospheres
Origin and properties of non-Lorentzian spectral lines in linear chains of
nanospheres are discussed. The lines are shown to be super-exponentially narrow
with the characteristic width proportional to exp[-C(h/a)^3] where C is a
numerical constant, h the spacing between the nanospheres in the chain and a
the sphere radius. The fine structure of these spectral lines is also
investigated.Comment: 9 pages, 4 figure
Amplification of evanescent waves in a lossy left-handed material slab
We carry out finite-difference time-domain (FDTD) simulations, with a
specially-designed boundary condition, on pure evanescent waves interacting
with a lossy left-handed material (LHM) slab. Our results provide the first
full-wave numerical evidence for the amplification of evanescent waves inside a
LHM slab of finite absorption. The amplification is due to the interactions
between the evanescent waves and the coupled surface polaritons at the two
surfaces of the LHM slab and the physical process can be described by a simple
model.Comment: 4 pages, 2 figure
Guided Modes in Negative Refractive Index Waveguides
We study linear guided waves propagating in a slab waveguide made of a
negative-refraction- index material, the so-called left-handed waveguide. We
reveal that the guided waves in left-handed waveguides possess a number of
peculiar properties, such as the absence of the fundamental modes, mode double
degeneracy, and sign-varying energy ux. In particular, we predict the existence
of novel types of guided waves with a dipole-vortex structure of the Pointing
vector.Comment: 4 pages, 4 figure
Refractive-index sensing with ultra-thin plasmonic nanotubes
We study the refractive-index sensing properties of plasmonic nanotubes with
a dielectric core and ultra-thin metal shell. The few-nm thin metal shell is
described by both the usual Drude model and the nonlocal hydrodynamic model to
investigate the effects of nonlocality. We derive an analytical expression for
the extinction cross section and show how sensing of the refractive index of
the surrounding medium and the figure-of-merit are affected by the shape and
size of the nanotubes. Comparison with other localized surface plasmon
resonance sensors reveals that the nanotube exhibits superior sensitivity and
comparable figure-of-merit
The Off-Shell Electromagnetic T-matrix: momentum-dependent scattering from spherical inclusions with both dielectric and magnetic contrast
The momentum- and frequency-dependent T-matrix operator for the scattering of
electromagnetic waves by a dielectric/conducting and para- or diamagnetic
sphere is derived as a Mie-type series, and presented in a compact form
emphasizing various symmetry properties, notably the unitarity identity. This
result extends to magnetic properties one previously obtained for purely
dielectric contrasts by other authors. Several situations useful to
spatially-dispersive effective-medium approximations to one-body order are
examined. Partial summation of the Mie series is achieved in the case of
elastic scattering.Comment: 22 pages. Preprint of a paper to appear in `Waves in Complex And
Random Media' ((c) Taylor and Francis, 2011
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