69,855 research outputs found
Solid immersion lens applications for nanophotonic devices
Solid immersion lens (SIL) microscopy combines the advantages of conventional microscopy with those of near-field techniques, and is being increasingly adopted across a diverse range of technologies and applications. A comprehensive overview of the state-of-the-art in this rapidly expanding subject is therefore increasingly relevant. Important benefits are enabled by SIL-focusing, including an improved lateral and axial spatial profiling resolution when a SIL is used in laser-scanning microscopy or excitation, and an improved collection efficiency when a SIL is used in a light-collection mode, for example in fluorescence micro-spectroscopy. These advantages arise from the increase in numerical aperture (NA) that is provided by a SIL. Other SIL-enhanced improvements, for example spherical-aberration-free sub-surface imaging, are a fundamental consequence of the aplanatic imaging condition that results from the spherical geometry of the SIL. Beginning with an introduction to the theory of SIL imaging, the unique properties of SILs are exposed to provide advantages in applications involving the interrogation of photonic and electronic nanostructures. Such applications range from the sub-surface examination of the complex three-dimensional microstructures fabricated in silicon integrated circuits, to quantum photoluminescence and transmission measurements in semiconductor quantum dot nanostructures
Parametrical modeling and design optimization of blood plasma separation device with microchannel mechanism
This paper presents an analysis of biofluid behavior in a T-shaped microchannel device and a design optimization for improved biofluid performance in terms of particle liquid separation. The biofluid is modeled with single phase shear rate non-Newtonian flow with blood property. The separation of red blood cell from plasma is evident based on biofluid distribution in the microchannels against various relevant effects and findings, including Zweifach-Fung bifurcation law, Fahraeus effect, Fahraeus-Lindqvist effect and cell free phenomenon. The modeling with the initial device shows that this T-microchannel device can separate red blood cell from plasma but the separation efficiency among different bifurcations varies largely. In accordance with the imbalanced performance, a design optimization is conducted. This includes implementing a series of simulations to investigate the effect of the lengths of the main and branch channels to biofluid behavior and searching an improved design with optimal separation performance. It is found that changing relative lengths of branch channels is effective to both uniformity of flow rate ratio among bifurcations and reduction of difference of the flow velocities between the branch channels, whereas extending the length of the main channel from bifurcation region is only effective for uniformity of flow rate ratio
Abelian functions associated with genus three algebraic curves
We develop the theory of Abelian functions associated with algebraic curves.
The growth in computer power and an advancement of efficient symbolic
computation techniques has allowed for recent progress in this area. In this
paper we focus on the genus three cases, comparing the two canonical classes of
hyperelliptic and trigonal curves. We present new addition formulae, derive
bases for the spaces of Abelian functions and discuss the differential
equations such functions satisfy.Comment: 34 page
Selected Topics in Classical Integrability
Basic notions regarding classical integrable systems are reviewed. An
algebraic description of the classical integrable models together with the zero
curvature condition description is presented. The classical r-matrix approach
for discrete and continuum classical integrable models is introduced. Using
this framework the associated classical integrals of motion and the
corresponding Lax pair are extracted based on algebraic considerations. Our
attention is restricted to classical discrete and continuum integrable systems
with periodic boundary conditions. Typical examples of discrete (Toda chain,
discrete NLS model) and continuum integrable models (NLS, sine-Gordon models
and affine Toda field theories) are also discussed.Comment: 40 pages, Latex. A few typos correcte
Lower limits and equivalences for convolution tails
Suppose is a distribution on the half-line . We study the
limits of the ratios of tails as . We
also discuss the classes of distributions ,
and .Comment: Published at http://dx.doi.org/10.1214/009117906000000647 in the
Annals of Probability (http://www.imstat.org/aop/) by the Institute of
Mathematical Statistics (http://www.imstat.org
An Effective Model for Crumpling in Two Dimensions?
We investigate the crumpling transition for a dynamically triangulated random
surface embedded in two dimensions using an effective model in which the
disordering effect of the variables on the correlations of the normals is
replaced by a long-range ``antiferromagnetic'' term. We compare the results
from a Monte Carlo simulation with those obtained for the standard action which
retains the 's and discuss the nature of the phase transition.Comment: 5 page
1D Potts, Yang-Lee Edges and Chaos
It is known that the (exact) renormalization transformations for the
one-dimensional Ising model in field can be cast in the form of a logistic map
f(x) = 4 x (1 - x) with x a function of the Ising couplings. Remarkably, the
line bounding the region of chaotic behaviour in x is precisely that defining
the Yang-Lee edge singularity in the Ising model.
In this paper we show that the one dimensional q-state Potts model for q
greater than or equal to 1 also displays such behaviour. A suitable combination
of Potts couplings can again be used to define an x satisfying f(x) = 4 x (1
-x). The Yang-Lee zeroes no longer lie on the unit circle in the complex z =
exp (h) plane, but their locus is still reproduced by the boundary of the
chaotic region in the logistic map.Comment: 6 pages, no figure
Decorating Random Quadrangulations
On various regular lattices (simple cubic, body centred cubic..) decorating
an edge with an Ising spin coupled by bonds of strength L to the original
vertex spins and competing with a direct anti-ferromagnetic bond of strength
alpha L can give rise to three transition temperatures for suitable alpha. The
system passes through ferromagnetic, paramagnetic, anti-ferromagnetic and
paramagnetic phases respectively as the temperature is increased.
For the square lattice on the other hand multiple decoration is required to
see this effect. We note here that a single decoration suffices for the Ising
model on planar random quadrangulations (coupled to 2D quantum gravity). Other
random bipartite lattices such as the Penrose tiling are more akin to the
regular square lattice and require multiple decoration to have any affect.Comment: 6 pages + 5 figure
Fourier's Law confirmed for a class of small quantum systems
Within the Lindblad formalism we consider an interacting spin chain coupled
locally to heat baths. We investigate the dependence of the energy transport on
the type of interaction in the system as well as on the overall interaction
strength. For a large class of couplings we find a normal heat conduction and
confirm Fourier's Law. In a fully quantum mechanical approach linear transport
behavior appears to be generic even for small quantum systems.Comment: 6 pages, 8 figure
Wavelet domain Bayesian denoising of string signal in the cosmic microwave background
An algorithm is proposed for denoising the signal induced by cosmic strings
in the cosmic microwave background (CMB). A Bayesian approach is taken, based
on modeling the string signal in the wavelet domain with generalized Gaussian
distributions. Good performance of the algorithm is demonstrated by simulated
experiments at arcminute resolution under noise conditions including primary
and secondary CMB anisotropies, as well as instrumental noise.Comment: 16 pages, 11 figures. Version 2 matches version accepted for
publication in MNRAS. Changes include substantial clarifications on our
approach and a significant reduction of manuscript lengt
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