2,248 research outputs found
Quantum state transmission in a cavity array via two-photon exchange
The dynamical behavior of a coupled cavity array is investigated when each
cavity contains a three-level atom. For the uniform and staggered intercavity
hopping, the whole system Hamiltonian can be analytically diagonalized in the
subspace of single-atom excitation. The quantum state transfer along the
cavities is analyzed in detail for distinct regimes of parameters, and some
interesting phenomena including binary transmission, selective localization of
the excitation population are revealed. We demonstrate that the uniform
coupling is more suitable for the quantum state transfer. It is shown that the
initial state of polariton located in the first cavity is crucial to the
transmission fidelity, and the local entanglement depresses the state transfer
probability. Exploiting the metastable state, the distance of the quantum state
transfer can be much longer than that of Jaynes-Cummings-Hubbard model. A
higher transmission probability and longer distance can be achieved by
employing a class of initial encodings and final decodings.Comment: 8 pages, 7 figures. to appear in Phys. Rev.
The research infrastructure of Chinese foundations, a database for Chinese civil society studies
This paper provides technical details and user guidance on the Research Infrastructure of Chinese Foundations (RICF), a database of Chinese foundations, civil society, and social development in general. The structure of the RICF is deliberately designed and normalized according to the Three Normal Forms. The database schema consists of three major themes: foundations’ basic organizational profile (i.e., basic profile, board member, supervisor, staff, and related party tables), program information (i.e., program information, major program, program relationship, and major recipient tables), and financial information (i.e., financial position, financial activities, cash flow, activity overview, and large donation tables). The RICF’s data quality can be measured by four criteria: data source reputation and credibility, completeness, accuracy, and timeliness. Data records are properly versioned, allowing verification and replication for research purposes
Physics-Augmented Data-EnablEd Predictive Control for Eco-driving of Mixed Traffic Considering Diverse Human Behaviors
Data-driven cooperative control of connected and automated vehicles (CAVs)
has gained extensive research interest as it can utilize collected data to
generate control actions without relying on parametric system models that are
generally challenging to obtain. Existing methods mainly focused on improving
traffic safety and stability, while less emphasis has been placed on energy
efficiency in the presence of uncertainties and diversities of human-driven
vehicles (HDVs). In this paper, we employ a data-enabled predictive control
(DeePC) scheme to address the eco-driving of mixed traffic flows with diverse
behaviors of human drivers. Specifically, by incorporating the physical
relationship of the studied system and the Hankel matrix update from the
generalized behavior representation to a particular one, we develop a new
Physics-Augmented Data-EnablEd Predictive Control (PA-DeePC) approach to handle
human driver diversities. In particular, a power consumption term is added to
the DeePC cost function to reduce the holistic energy consumption of both CAVs
and HDVs. Simulation results demonstrate the effectiveness of our approach in
accurately capturing random human driver behaviors and addressing the complex
dynamics of mixed traffic flows, while ensuring driving safety and traffic
efficiency. Furthermore, the proposed optimization framework achieves
substantial reductions in energy consumption, i.e., average reductions of 4.83%
and 9.16% when compared to the benchmark algorithms
RAR-PINN algorithm for the data-driven vector-soliton solutions and parameter discovery of coupled nonlinear equations
This work aims to provide an effective deep learning framework to predict the
vector-soliton solutions of the coupled nonlinear equations and their
interactions. The method we propose here is a physics-informed neural network
(PINN) combining with the residual-based adaptive refinement (RAR-PINN)
algorithm. Different from the traditional PINN algorithm which takes points
randomly, the RAR-PINN algorithm uses an adaptive point-fetching approach to
improve the training efficiency for the solutions with steep gradients. A
series of experiment comparisons between the RAR-PINN and traditional PINN
algorithms are implemented to a coupled generalized nonlinear Schr\"{o}dinger
(CGNLS) equation as an example. The results indicate that the RAR-PINN
algorithm has faster convergence rate and better approximation ability,
especially in modeling the shape-changing vector-soliton interactions in the
coupled systems. Finally, the RAR-PINN method is applied to perform the
data-driven discovery of the CGNLS equation, which shows the dispersion and
nonlinear coefficients can be well approximated
Transformable Super-Isostatic Crystals Self-Assembled from Segment Colloidal Rods
Colloidal particles can spontaneously self-assemble into ordered structures,
which not only can manipulate the propagation of light, but also vibration or
phonons. Using Monte Carlo simulation, we study the self-assembly of perfectly
aligned segment rod particles with lateral flat cutting. Under the help of
surface attractions, we find that particles with different cutting degree can
self-assemble into different crystal phases characterized by bond coordination
that varies from 3 to 6. Importantly, we identify a transformable
super-isostatic structures with \emph{pgg} symmetry and redundant bonds
(). We find that this structure can support either the soft bulk model or
soft edge model depending on its Poisson's ratio which can be tuned from
positive to negative by a uniform soft deformation. Importantly, the bulk soft
modes are associated with states of self-stress along the direction of zero
strain during the uniform soft deformation. This self-assembled transformable
super-isostatic structure may act as mechanical metamaterials with potential
application in micro-mechanical engineering.Comment: 11pages,5 figure
Steady-State Response of Axially Moving Viscoelastic Beams With Pulsating Speed:
Abstract Principal parametric resonance in transverse vibration is investigated for viscoelastic beams moving with axial pulsating speed. A nonlinear partial-differential equation governing the transverse vibration is derived from the dynamical, constitutive, and geometrical relations. Under certain assumption, the partial-differential reduces to an integro-partialdifferential equation for transverse vibration of axially accelerating viscoelastic nonlinear beams. The method of multiple scales is applied to two equations to calculate the steady-state response. Closed form solutions for the amplitude of the vibration are derived from the solvability condition of eliminating secular terms. The stability of straight equilibrium and nontrivial steady-state response are analyzed by use of the Lyapunov linearized stability theory. Numerical examples are presented to highlight the effects of speed pulsation, viscoelascity, and nonlinearity and to compare results obtained from two equations
Minkowski's lost legacy and hadron electromagnetism
We revisit Minkowski's lost legacy on relativistic electromagnetism in order
to resolve long-standing puzzles over the charge distribution of relativistic
systems like hadrons. Hadrons are unique relativistic electromagnetic systems
characterized by their comparable size and Compton wavelength . As such, it was recently realized that the traditional Sachs
definition of the charge distribution based on a non-relativistic formula is
invalid. We explain that this is the same problem pursued by Lorentz, Einstein
and others, on the electromagnetism of a moving body. We show how various
charge distributions proposed in hadronic physics naturally emerge as the
multipole moment densities in the macroscopic theory of relativistic
electromagnetism.Comment: 7 pages, 2 figures; published on Physics Letters
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