584,429 research outputs found
A Double Layer Electromagnetic Cloak And GL EM Modeling
In this paper, we propose a novel electromagnetic (EM) cloaking structure
that consists of two annular layers between three spherical shells and model
its performance numerically and theoretically by using a Global and Local EM
field (GL) method. The two annular layers contain distinct cloaking materials:
the outer layer provides invisibility; the inner layer is fully absorbing. The
cloaking materials are weakly degenerative. The wavefield from an EM source
located outside the cloak propagates as in free space outside the outer shell,
never be disturbed by the cloak and does not penetrate into the inner absorbing
layer and concealment.
The field of a source located inside inner layer or the cloaked concealment
is completely absorbed by the inner layer and never reaches the outside of the
middle shell, Moreover, the EM wavefield excited in concealment is not
disrupted by the cloak. There exists no Maxwell EM wavefield can be excited in
a single layer cloaked concealment which is filled by normal material.
Moreover, we find a negative dielectric and positive susceptibility
metamaterial to fill into the concealment, such that the interior EM wave
propagates from the concealment to free space through the single layer cloak.
Therefore, the double layer cloak is important and necessary for complete
invisibility. Numerical simulations and theoretical analysis verifying these
properties are performed using the GL EM modeling method that we described in
this paper.Comment: A Novel GL double Layer cloaks are proposed. Moreover, we discovered
a single negative refractive index metamaterial. We fill it inside the single
cloaked concealment, the EM wave field excited inside the this material in
the concealment propagates out to free space through the single layer cloak.
13 figures are include
A Multigrid Method for the Ground State Solution of Bose-Einstein Condensates
A multigrid method is proposed to compute the ground state solution of
Bose-Einstein condensations by the finite element method based on the
multilevel correction for eigenvalue problems and the multigrid method for
linear boundary value problems. In this scheme, obtaining the optimal
approximation for the ground state solution of Bose-Einstein condensates
includes a sequence of solutions of the linear boundary value problems by the
multigrid method on the multilevel meshes and a series of solutions of
nonlinear eigenvalue problems on the coarsest finite element space. The total
computational work of this scheme can reach almost the optimal order as same as
solving the corresponding linear boundary value problem. Therefore, this type
of multigrid scheme can improve the overall efficiency for the simulation of
Bose-Einstein condensations. Some numerical experiments are provided to
validate the efficiency of the proposed method.Comment: 15 pages and 6 figures. arXiv admin note: substantial text overlap
with arXiv:1405.715
A GL Double Layer EM Cloaks In Broad Frequency Band And Reciprocal Law
In this paper, we propose a novel GLWF double layer EM cloak in the broad
frequency band. The GLWF double layer cloak consists of two sphere annular
layers, two type cloak materials are proposed and installed in its each layer,
respectively. The outer layer of the GL cloak has the invisible function in
broad frequency band, while its inner layer has the fully absorption and rapid
delay function. The GLWF double layer cloak overcomes the following
difficulties of the single layer PS cloak. (1) There exists no EM wavefield can
be excited inside the concealment of the PS cloak, the concealment of the PS
cloak is blind. Our GL double layer cloak recovered that the EM wave field can
be excited inside the concealment of the GL double layer cloak. (2) There is
exceeding light speed physical violation in PS cloak, its invisibility only in
very narrow frequency band. Our GLWF double layer cloak corrects the violation.
(3) The reciprocal law is satisfied in our GL double cloak media. However, the
PS cloak damaged the reciprocal law.. The simulations and comparisons of the EM
wave field propagation through the GLWF double cloak, GL double cloak and GL
double layer with PS outer layer are presented to show the advantages of the
GLWF double layer EM cloak The GL double layer cloaks are proposed by our GL EM
modeling and inversion.
The 3D GL EM modeling simulations for the double layer cloak are presented.
The copyright and patent of the GLWF double layer cloak materials and GL EM
modeling and inversion in this paper are reserved by authors in GL Geophysical
Laboratory.Comment: 8 pages and 11 figures are included in this paper. Please send
comments to [email protected]
Computable Error Estimates for Ground State Solution of Bose-Einstein Condensates
In this paper, we propose a computable error estimate of the Gross-Pitaevskii
equation for ground state solution of Bose-Einstein condensates by general
conforming finite element methods on general meshes. Based on the proposed
error estimate, asymptotic lower bounds of the smallest eigenvalue and ground
state energy can be obtained. Several numerical examples are presented to
validate our theoretical results in this paper.Comment: 19 pages, 9 figures. arXiv admin note: text overlap with
arXiv:1601.0156
Problem On The Acoustic Cloak By to Transformation
The to radial spherical coordinate transformation method can be
making electromagnetic (EM) invisible cloak. However the cloak by
transformation optic has infinite speed and exceeding light speed etc
fundamental difficulties. In this paper, we discover problem on acoustic cloak
by transformation and prove that in the to radial spherical
coordinate transformation, the pressure wave field is invariant,
in the physical inner spherical surface boundary , is not zero.
the acoustic field propagation penetrate into the inner sphere .Therefore, the inner sphere can not be cloaked. The GL
simulation figures of the pressure acoustic wave propagation penetrate into the
inner sphere are presented in figure 1 to figure 12.The pressure
wave is setting to zero that cause the scattering wave to disturb incident
pressure acoustic wave outside of the outer sphere that make the
whole sphere will be deltected. GL method simulation is presented
in figure 13. we discovered and proved that to sphere radial
transformation can not be used to induce acoustic no scattering cloak.Comment: 18 pages, 112 formulas and 2 figures in this paper, Welcome comments
from colleagues. It is academical publication for open review. Please
colleague send comments and question to me by email [email protected]. If
colleague use this paper, please be sure cite my paper in his papers. The
Paper is different from other paper
Soft supersymmetry breaking of 4d SCFT
A classification of soft SUSY breaking deformation of general four
dimensional SCFT is provided. Given the large class of newly
discovered SCFTs and their known properties such as the central
charges and full information of BPS operators, it is possible to get a huge
number of new SCFTs and non-supersymmetric CFTs. Many
properties of these new SCFTs such as central charges, chiral
spectrum and Seiberg duality can be derived from known information of parent
SCFT.Comment: 17 pages, 2 figure
Talk&Learn: Improving Conversation Experience and Creating Opportunities for Foreign Language Learning
Existing Real-Time Translation Interfaces (RTTI) do not provide experience as
natural and efficient as monolingual communication. Also, such systems do not
provide functions supporting language learning. This results in the waste of
both time and potential language context. In order to overcome the above
limitations, we propose a solution named "Talk&Learn". Its core idea is to
rearrange ("Delay-Match") the real-time videos and translated texts or
speeches, so as to gain better naturalness and efficiency. At the same time,
this will create extra free time for users. So we further propose to utilize
the free time for contextual language learning
Model for processive nucleotide and repeat additions by the telomerase
A model is presented to describe the nucleotide and repeat addition
processivity by the telomerase. In the model, the processive nucleotide
addition is implemented on the basis of two requirements: One is that stem IV
loop stimulates the chemical reaction of nucleotide incorporation, and the
other one is the existence of an ssRNA-binding site adjacent to the polymerase
site that has a high affinity for the unpaired base of the template. The
unpairing of DNA:RNA hybrid after the incorporation of the nucleotide paired
with the last base on the template, which is the prerequisite for repeat
addition processivity, is caused by a force acting on the primer. The force is
resulted from the unfolding of stem III pseudoknot that is induced by the
swinging of stem IV loop towards the nucleotide-bound polymerase site. Based on
the model, the dynamics of processive nucleotide and repeat additions by
Tetrahymena telomerase are quantitatively studied, which give good explanations
to the previous experimental results. Moreover, some predictions are presented.
In particular, it is predicted that the repeat addition processivity is mainly
determined by the difference between the free energy required to disrupt the
DNA:RNA hybrid and that required to unfold the stem III pseudoknot, with the
large difference corresponding to a low repeat addition processivity while the
small one corresponding to a high repeat addition processivity.Comment: 28 pages, 5 figure
Some examples of quasiisometries of nilpotent Lie groups
We construct quasiisometries of nilpotent Lie groups. In particular, for any
simply connected nilpotent Lie group N, we construct quasiisometries from N to
itself that is not at finite distance from any map that is a composition of
left translations and automorphisms. We also construct biLipschitz maps of the
Heisenberg groups that send vertical lines to non-vertical curves
Three dimensional Seiberg-like duality and tropical cluster algebra
Seiberg-like duality of three dimensional N=2 Chern-Simons-Matter quiver
gauge theory is shown to have a chiral double tropical cluster algebra
structure. We use cluster algebra results to study combinatorial aspects of
these theories such as classification, supersymmetry breaking, etc.Comment: 18 pages, 5 figures. References added, typo correcte
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