367,236 research outputs found
Thermal response of photovoltaic cell to laser beam irradiation
This paper firstly presents the concept of using dual laser beam to irradiate
the photovoltaic cell, so as to investigate the temperature dependency of the
efficiency of long distance energy transmission. Next, the model on the
multiple reflection and absorption of any monochromatic light in multilayer
structure has been established, and the heat generation in photovoltaic cell
has been interpreted in this work. Then, the finite element model has been set
up to calculate the temperature of photovoltaic cell subjected to laser
irradiation. Finally, the effect of temperature elevation on the efficiency and
reliability of photovoltaic cell has been discussed to provide theoretical
references for designing the light-electricity conversion system.Comment: Also appeared in the proceedings for "The Heat Transfer Symposium,
Beijing, China, 6-9, May, 2014
Scalar field quasinormal frequencies of Reissner-Nordstr\"om black hole surrounded by quintessence by using he continued fraction method
We evaluate the quasinormal modes of massless scalar field around
Reissner-Nordstrm black hole surrounded by a static and
spherically symmetric quintessence by using the continued fraction method. The
appropriate Frobenius series for three special cases of the quintessence
parameter and are derived successfully. We show
that the variation of quasinormal frequencies with charge of the black hole and
the quintessential parameters. The numerical results show that quintessence
field decreases oscillation frequencies of all angular momentum modes and
increases the damping time of modes.Comment: 17 pages, 2 figure
Weighted projective lines of tubular type and equivariantization
We prove that the categories of coherent sheaves over weighted projective
lines of tubular type are explicitly related to each other via the
equivariantization with respect to certain cyclic group actions
Dynamical current-current correlation in the two-dimensional parabolic Dirac system
We theoretically investigate the current-current correlation of the
two-dimensional (2D) parabolic Dirac system in hexogonal lattice. The
analytical expressions of the random phase approximation (RPA) susceptibility,
Ruderman-Kittel-Kasuya-Yosida (RKKY) Hamiltonian, and the diamagnetic orbital
susceptibility in noninteracting case base on the density-density or
current-current correlation function are derived and quantitatively analyzed.
In noninteracting case, the dynamical polarization with- in RPA and spin
transverse susceptibility as well as the RKKY interaction (when close to the
half-filling) are related to the the current-current response in the 2D
parabolic Dirac system. Both the case of anisotropic dispersion and isotropic
dispersion are discussed
Accessible values of Assouad and the lower dimensions of subsets
Let be a subset of a doubling metric space . We prove that for any
, where denotes the Assouad dimension, there
exists a subset of such that . We also show that the same
statement holds for the lower dimension .Comment: 13 page
The singularity category of an algebra with radical square zero
To an artin algebra with radical square zero, a regular algebra in the sense
of von Neumann and a family of invertible bimodules over the regular algebra
are associated. These data describe completely, as a triangulated category, the
singularity category of the artin algebra. A criterion on the Hom-finiteness of
the singularity category is given in terms of the valued quiver of the artin
algebra.Comment: Comments are welcom
A note on Serre duality and equivariantization
For an abelian category with a Serre duality and a finite group action, we
compute explicitly the Serre duality on the category of equivariant objects.
Special cases and examples are discussed. In particular, an abelian category
with a periodic Serre duality and its equivariantization are studied.Comment: Comments are welcome
Two-dimensional parabolic Dirac system in the presence of non-magnetic and magnetic impurities
We theoretically investigate the effect of the non-magnetic and magnetic
impurities to the 2D parabolic Dirac system. The induced charge density by the
charged impuri- ty is obtained by the linear response theory within the random
phase approximation. We also detailly calculate the RKKY interaction between
two magnetic impurities placed within the 2D sheet of the Dirac materials with
isotropic and anisotropic dis- persion. For the anisotropic dispersion, the
RKKY interaction is also anisotropic and related to the lattice parameters
which can be obtained throuh the DFT calculation or the experiments. The
fearures of the RKKY interaction also can be treated as a signature of the
topological phase transition as well as the change of Berry curvature. Our
results are also illuminating to the study of the static screening and the RKKY
interaction of the isotropic or anisotropic 3D Dirac or Weyl systems
Electronic transport and the related anomalous effects in silicene-like hexagonal lattice
We investigate the anomalous effects due to the Berry correction and the
considerable perturbations in the silicene-like hexagonal lattice system. The
Berry curvature in periodic Bloch band system which related to the
electromagnetic field is explored, the induced transverse anomalous velocity
gives rise to the intrinsic Hall conductivity (without the vertex correction)
expecially in the quantum anomalous Hall phase. The quantum anomalous Hall
effect which related to the anomalous velocity term is detected, including the
band avoided corssing effect and the generated special band gap. %{Enlarged
Galilean symmetry of anyons and the Hall effect} The topological spin transport
is affected by the Berry curvature %{Topological spin transport of a
relativistic electron} %{Anomalous direction for skyrmion bubble motion} and
the spin-current-induced Skyrmion spin texture motion is contrasted between the
quantum spin Hall effect and quantum anomalous Hall effect. Since silicene
involving the orbital degree of freedom, the orbital magnetic moment and
orbital magnetization contributes significantly to the electronic transport
properties of silicene %{Photoinduced quantum spin and valley Hall effects, and
orbital magnetization in monolayer MoS2} as explored in this article. We also
investigate the electronic tunneling properties of silicene in Josephon
junction with the electric-field-induced Rashba-coupling, the anomalous effect
due to the Berry phase is mentioned. Our results is meaningful to the
application of the spintronics and valleytronics base on the silicene-like
topological insulators
Analysis of the behavior of singlet pairs in inorganic crystal XOCl(X=Ti,Bi)
This article explore the behavior of singlet pairs in Inorganic crystals and
take the Ti-Ti and Bi-Bi dimer for example, including the transition in
critical temperture by directly or indirectly. Through the analysis, It is
proposed that with the decrease of temperature, the strength of spin-orbit
coupling (SOC) increases and the phase difference also increases. In the
one-dimensional spin 1/2 chain system of TiOCl and BiOCl crystals, the
possibility of reversible parameter modulation is proposed by the calculation
of the first principle analyzing the process and analysis of the structural
phase transition process. It's shown that the different sturcture transition is
relate to the difference of the dimer structure and the fluctuation of orbital
order through the comparative study of TiOCl and BiOCl
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