13,905 research outputs found
Effects of energetic particles on zonal flow generation by toroidal Alfven eigenmode
Generation of zonal ow (ZF) by energetic particle (EP) driven toroidal Alfven
eigenmode (TAE) is investigated using nonlinear gyrokinetic theory. It is found
that, nonlinear resonant EP contri- bution dominates over the usual Reynolds
and Maxwell stresses due to thermal plasma nonlinear response. ZF can be forced
driven in the linear growth stage of TAE, with the growth rate being twice the
TAE growth rate. The ZF generation mechanism is shown to be related to
polarization induced by resonant EP nonlinearity. The generated ZF has both the
usual meso-scale and micro- scale radial structures. Possible consequences of
this forced driven ZF on the nonlinear dynamics of TAE are also discussed.Comment: To be submitted to Physics of Plasma
On fast radial propagation of parametrically excited geodesic acoustic mode
The spatial and temporal evolution of parametrically excited geodesic
acoustic mode (GAM) initial pulse is investigated both analytically and
numerically. Our results show that the nonlinearly excited GAM propagates at a
group velocity which is, typically, much larger than that due to finite ion
Larmor radius as predicted by the linear theory. The nonlinear dispersion
relation of GAM driven by a finite amplitude drift wave pump is also derived,
showing a nonlinear frequency increment of GAM. Further implications of these
findings for interpreting experimental observations are also discussed
Model anisotropic quantum Hall states
Model quantum Hall states including Laughlin, Moore-Read and Read-Rezayi
states are generalized into appropriate anisotropic form. The generalized
states are exact zero-energy eigenstates of corresponding anisotropic two- or
multi-body Hamiltonians, and explicitly illustrate the existence of geometric
degrees of in the fractional quantum Hall effect. These generalized model
quantum Hall states can provide a good description of the quantum Hall system
with anisotropic interactions. Some numeric results of these anisotropic
quantum Hall states are also presented.Comment: 10 pages, 5 figure
Scheme for remote implementation of partially unknown quantum operation of two qubits in cavity QED
By constructing the recovery operations of the protocol of remote
implementation of partially unknown quantum operation of two qubits [An Min
Wang: PRA, \textbf{74}, 032317(2006)], we present a scheme to implement it in
cavity QED. Long-lived Rydberg atoms are used as qubits, and the interaction
between the atoms and the field of cavity is a nonresonant one. Finally, we
analyze the experimental feasibility of this scheme.Comment: 7 pages, 2 figure
An efficient wireless power transfer system with security considerations for electric vehicle applications
published_or_final_versio
Effect of active carbonyl-carboxyl ratio on dynamic Schiff base crosslinking and its modulation of high-performance oxidized starch-chitosan hydrogel by hot extrusion 3D printing
The quest to develop 3D starch-based printing hydrogels for the controlled release of active substances with excellent mechanical and printing properties has gained significant attention. This work introduced a facile method based on crosslinking via Schiff base reaction for preparing bicomponent hydrogels. The method involved the utilization of customizable oxidized starch (OS) and chitosan (CS), enabling superior printing performance through the precise control of various active carbonyl-carboxyl ratios (ACR, 2:1, 1:1, and 2:3, respectively) of OS. OS-CS hydrogel (OSC) with an ACR level of 2:1 (OS-2-y%CS) underwent rearrangement during printing environment, fostering increased Schiff base reaction with a higher crosslinking degree and robust high structural recovery (>95 %). However, with decreasing ACR levels (from 2:1 to 2:3), the printing performance and mechanical strength of printed OSC (POSC) declined due to lower Schiff base bonds and increased phase separation. Compared with printed OS, POS-2-2%CS exhibited a remarkable 1250.52 % increase in tensile strength and a substantial 2424.71 % boost in compressive strength, enhanced shape fidelity and notable self-healing properties. Moreover, POS-2-2%CS exhibited stable diffusive drug release, showing potential application in the pH-responsive release of active substances. Overall, controlling the active carbonyl-carboxyl ratios provided an efficient and manageable approach for preparing high-performance 3D-printed hydrogels
Far-infrared optical properties of the pyrochlore spin ice compound Dy2Ti2O4
Near normal incident far-infrared reflectivity spectra of [111] dysprosium
titanate (Dy2Ti2O4) single crystal have been measured at different
temperatures. Seven phonon modes (eight at low temperature) are identified at
frequency below 1000 cm-1. Optical conductivity spectra are obtained by fitting
all the reflectivity spectra with the factorized form of the dielectric
function. Both the Born effective charges and the static optical primitivity
are found to increase with decreasing temperature. Moreover, phonon linewidth
narrowering and phonon modes shift with decreasing temperature are also
observed, which may result from enhanced charge localization. The redshift of
several low frequency modes is attributed to the spin-phonon coupling. All
observed optical properties can be explained within the framework of nearest
neighbor ferromagnetic(FM) spin ice model
On the Quantum Mechanics for One Photon
This paper revisits the quantum mechanics for one photon from the modern
viewpoint and by the geometrical method. Especially, besides the ordinary
(rectangular) momentum representation, we provide an explicit derivation for
the other two important representations, called the cylindrically symmetrical
representation and the spherically symmetrical representation, respectively.
These other two representations are relevant to some current photon experiments
in quantum optics. In addition, the latter is useful for us to extract the
information on the quantized black holes. The framework and approach presented
here are also applicable to other particles with arbitrary mass and spin, such
as the particle with spin 1/2.Comment: 15 pages, typos corrected, references added, corrections and
improvements made owing to the anonymous referee's responsible and helpful
remarks, accepted for publication in Journal of Mathematical Physics:
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