7,899 research outputs found
Lasing with cell-endogenous fluorophores: parameters and conditions
The notion of lasing with biologics has recently been realized and has since
rapidly developed with the collective objective of creating lasers . One limitation of achieving this goal is the requirement of exogenous
laser dyes and fluorescent materials. To circumvent this, we investigate the
use of cell-endogenous fluorophores - sources of cell autofluorescence - as
laser gain material. In this work, we study the lasing potential and efficiency
of flavins and reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H)
using a dye lasing model based on coupled rate equations. Analytical solutions
for one- and two-photon pumped system were used in multi-parameter studies. We
found that at physiological conditions, lasing can be supported by NAD(P)H with
cavity quality factors of . With the further consideration of damage
thresholds, we recommend the use of flavins as they entail lower threshold
requirements. We then identify potential parameters for engineering to make the
lasing of flavins feasible even at their low physiological intracellular
concentrations. We also note the higher threshold requirements and lower
efficiencies of two-photon pumping, but recognize its potential for realizing
lasing
A note on the discrete Fourier restriction problem
In this paper, we establish a general discrete Fourier restriction theorem.
As an application, we make some progress on the discrete Fourier restriction
associated with KdV equation.Comment: Proc. Amer. Math. Soc. to appea
Domain structures and superdislocations of La0.7Ca0.3MnO3 thin films grown on SrTiO3 substrates
The domain structures and dislocations in epitaxial thin films of
La0.7Ca0.3MnO3 grown on SrTiO3 substrates by pulsed laser deposition were
investigated using Bragg-contrast diffraction and high-resolution transmission
electron microscopy. It revealed that the films contained the 1/2[100]o and
1/2[10-1]o types partial threading dislocations, the 90 degree - and 120 degree
- types of twin- domain boundaries, and two types 1/2[010]o, 1/2[111]o, of
antiphase boundaries, which are often observed in bulk materials. In addition,
two types of superdislocations were detected; one consisted of two 1/2[111]o
dislocations and a 1/2[111]o antiphase boundary, and the other was composed of
two 1/2[010]o dislocations and a 1/2[010]o antiphase boundary. These
superdislocations, domain boundaries, and their relationships were extensively
explored.Comment: 19 pages, 6 figure
-Dini conditions and limiting behavior of weak type estimates for singular integrals
In 2006, Janakiraman [10] showed that if with mean value zero on
satisfies the condition then for the singular integral operator
with homogeneous kernel, the following limiting behavior holds:
In the present paper, we prove that if replacing the condition by
more general condition, the -Dini condition, then the limiting behavior
still holds for the singular integral . In particular,
we give an example which satisfies the -Dini condition, but does not
satisfy . Hence, we improve essentially the above result given in [10].
To prove our conclusion, we show that the -Dini conditions defined
respectively via the rotation and translation on are equivalent
(see Theorem 2.5 below), which has its own interest in the theory of singular
integrals. Moreover, similar limiting behavior for the fractional integral
operator with homogeneous kernel is also established in
this paper.Comment: 18 pages, typos are corrected, to appear in Rev. Mat. Iberoa
Weak type (1,1) bound criterion for singular integral with rough kernel and its applications
In this paper, a weak type (1,1) bound criterion is established for singular
integral operator with rough kernel. As some applications of this criterion, we
prove some important operators with rough kernel in harmonic analysis, such as
Calder\'on commutator, higher order Calder\'on commutator, general Calder\'on
commutator, Calder\'on commutator of Bajsanski-Coifman type and general
singular integral of Muckenhoupt type, are all of weak type (1,1).Comment: 27 pages. To appear in Trans. Amer. Math. So
Weighted bound for commutators
Let be the Calder\'on-Zygmund convolution kernel on . Define the commutator associated with and by
Recently, Grafakos and Honz\'{\i}k [5] proved that is of weak type (1,1)
for . In this paper, we show that is also weighted weak type (1,1)
with the weight for . Moreover, we prove that
is bounded on weighted for all .Comment: Some misprints and the reference [6] of published version are
corrected. Published in J.Geom.Anal(2015
QoS-aware Full-duplex Concurrent Scheduling for Millimeter Wave Wireless Backhaul Networks
The development of self-interference (SI) cancelation technology makes
full-duplex (FD) communication possible. Considering the quality of service
(QoS) of flows in small cells densely deployed scenario with limited time slot
(TS) resources, this paper introduces the FD communication into the concurrent
scheduling problem of millimeter-wave (mmWave) wireless backhaul network. We
propose a QoS-aware FD concurrent scheduling algorithm to maximize the number
of flows with their QoS requirements satisfied. Based on the contention graph,
the algorithm makes full use of the FD condition. Both residual
self-interference (RSI) and multi-user interference (MUI) are considered.
Besides, it also fully considers the QoS requirements of flows and ensures the
flows can be transmitted at high rates. Extensive simulations at 60GHz
demonstrate that with high SI cancelation level and appropriate contention
threshold, the proposed FD algorithm can achieve superior performance in terms
of the number of flows with their QoS requirements satisfied and the system
throughput compared with other stateof-of-the-art schemes.Comment: 9 pages, 10 figure
Jump and variational inequalities for rough operators
In this paper, we systematically study jump and variational inequalities for
rough operators, whose research have been initiated by Jones {\it et al}. More
precisely, we show some jump and variational inequalities for the families
of truncated singular integrals
and of averaging operators with rough kernels,
which are defined respectively by and where the kernel
belongs to or or
(the condition introduced by Grafakos and
Stefanov). Some of our results are sharp in the sense that the underlying
assumptions are the best known conditions for the boundedness of corresponding
maximal operators.Comment: 32 page
Compactness of commutators of bilinear maximal Calder\'{o}n-Zygmund singular integral operators
Let be a bilinear Calder\'{o}n-Zygmund singular integral operator and
be its corresponding truncated maximal operator. The commutators in the
- entry and the iterated commutators of are defined by
\begin{align*}
T_{\ast,(b_1,b_2)}(f,g)(x)=\sup\limits_{\delta>0}\bigg|\iint_{|x-y|+|x-z|>\delta}
K(x,y,z)(b_1(y)-b_1(x))(b_2(z)-b_2(x))f(y)g(z)dydz\bigg|. \end{align*} In this
paper, the compactness of the commutators , and
on is established.Comment: New version, corrected the fomer mistake
Riesz transforms associated with higher-order Schr\"odinger type operators
In this paper, let be a Schr\"{o}dinger type operator where
is higher order elliptic operator with complex coefficients in
divergence form and is signed measurable function, under the strongly
subcritical assumption on , the authors study the boundedness of
Riesz transforms for and obtain a sharp result.
Furthermore, the authors impose extra regularity assumptions on to obtain
the boundedness of Riesz transforms for . As
an application, the main results can be applied to the operator
for suitable $\gamma
- β¦