Dynamics of entangled trajectories in quantum phase space
Quantum phase space theory is widely used to investigate physical, and chemical questions. It gives us a powerful tool to study the relations between the classical and quantum world. In quantum phase space theory, entangled molecular dynamics method is developed based on quantum Liouville equation. It is different from classical Hamilton dynamics, the trajectories are entangled i.e. not independent with each other. The quantum effect in the system can be described using the semiclassical theory, and give a vivid physical picture. The quantum tunneling, photodissociation, and self-correlation are investigated using the entangled trajectory. In this paper, we review the recent development in this field.
Broadband low-RCS metamaterial absorber based on electromagnetic resonance separation
Shielding effectiveness of a metal cavity covered by a material with a medium conductivity
The electromagnetic shielding effectiveness (SE) of a metal cavity covered by a material of medium conductivity is investigated theoretically by using an equivalent circuit method based on the transmission line and waveguide theory. The validity of the theoretical model is verified by comparison with the electromagnetic simulation software. The position effect and the resonance effect of the SE are calculated. A method for evaluating the SE of materials is suggested. With this method, the influence of the resonance effect and the position effect can be impaired greatly, also the SE of materials against plane wave can be evaluated directly.
Average capacity of free-space optical systems for a Laguerre-Gaussian beam propagating through non-Kolmogorov turbulence
Discussion on the problem of random media matching with the PCF for RFL
Measurement of the spatial coherence of extended light source by twin beams-interference method
Variational multi-source image fusion based on the structure tensor
Study on the relationship between the population of metastable state and time delay in an erbium-doped optical fiber
Investigation of bidirectional dual-channel long-distance chaos secure communication based on 1550nm vertical-cavity surface-emitting lasers
Influence of electrolytes on diffusion properties of colloidal particles in dense suspensions
Stability study on high sensitive CO monitoring in near-infrared
In-fiber Mach-Zehnder interferometer based on fiber core etched air-bubble and core diameter mismatch for liquid refractive index sensing
A kind of optical fiber liquid refractive index sensor is proposed based on fiber core etched air-bubble and core diameter mismatched in-fiber Mach-Zehnder interferometer. A core etched standard single-mode fiber is spliced to another core etched standard single-mode fiber (SMF) to form an air bubble at the connecting point, and a 20 mm thinned fiber is cascaded (TCF) by fusion splicing method, which is 20 mm apart from the bubble, then a leading-mode fiber is spliced to the thinned fiber to form a structure of SMF-(air-bubble)-SMF-TCF-SMF in-fiber Mach-Zehnder interferometer liquid refractive index sensor. The air-bubble and the two fiber core diameter mismatched points serve as optical couplers for modes conversion. The transmission spectrum of sensor is studied by experiment. Results shows that the peak power changes with respect to surrounding refractive index with good linearity. The sensitivity of the sensor is 142.537 dB/RIU in the range of 1.351–1.402 with linearity of 0.996, making it a good candidate for bio-chemical measurements.
Study on the partial gating smart network camera for controlling strong light intensity based on DSP and liquid crystal
Investigation of the crystal and optical properties of ZnS thin films deposited at different temperature
Supercontinuum experimental study of V-type photonic crystal fiber with high birefringence
Study on tapered chirped fiber grating filter
A gradient representation of first-order Lagrange system
Asymptotic analysis for effect of thermal inertia on thermal behaviors
Simulation of two-dimensional droplet collisions based on SPH method of multi-phase flows with large density differences
Effects of surface tension on Rayleigh-Taylor instability
In this paper, Layzer’s model which has a simple velocity potential, and Zufiria’s model are extended to the case of non-ideal fluids, and the effects of surface tension on Rayleigh-Taylor instability are investigated. Firstly, the analytical expressions for the asymptotic bubble velocity and curvature are obtained in the two models. Secondly, the effects of surface tension on Rayleigh-Taylor instability are studied systematically. Finally, the two models are compared with each other and the comparisons with numerical simulation are made as well. The results indicate that the surface tension depresses the bubble velocity, but does not affect the bubble curvature. The Layzer’s model with the simple velocity potential gives a smaller bubble velocity than that predicted by the Layzer’s model with a complex velocity potential. But the bubble velocity predicted by the Layzer’s model with the simple velocity potential is larger than that obtained by Zufiria’s model. Both Layzer’s models lead to the same bubble velocity when the Atwood number is A = 1.
Interaction between bubble and free surface near vertical wall with inclination
Study on the interaction between bubble and free surface near an inclined vertical wall is carried out in this paper. Firstly, boundary element model for bubble dynamics based on incompressible potential flow is established, and the solid wall is modeled using the images of bubble and free surface. Then, through the numerical model, bubble dynamics near the walls with various inclination angles are studied respectively. We find that the inclination would lead discontinuity of the boundary condition of intersection between free surface and solid wall, which can affect its motion nonlinearly. Finally, the influence of the inclination angle on the bubble and spike dynamics is analyzed.
Dynamics of insoluble surfactant-laden thin films flow over inclined random topography
Influence of site-selective doping of Er3+ on the upconversion spectra in KPb2Br5
Different concentrations of Er3+ doped in KPb2Br5 powders are prepared by solid-state reaction method. The upconversion spectra under the excitation of 980 nm laser are characterized and show the concentration-related change in emission band. With the doping concentration of 2.5 mol%, the sample exhibits mainly two green emission peaks at 530 nm and 550 nm, which correspond to the transitions of 2H11/2 and 4S3/2 levels to ground state 4I15/2 respectively. When the doping concentration of Er3+ is increased to 5 mol%, the upconversion emission is dominated by 490 nm, related to the transition of 4F7/2 to 4I15/2. Increasing the doping concentration up to 7.5 mol%, the emission quenching is observed throughout and the emission band appears mainly at 690 nm which comes from the transition of 4F9/2 to 4I15/2. The influence of possible substitution of Er3+ on lattice constant and upconversion emission properties of KPb2Br5 are discussed based on the first-principles calculation and Judd-Ofelt theory. The results show that the substitution of Er3+ in KPb2Br5 is dominated for Pb(1) in low concentration. When increasing the Er3+ doping concentration, it may substitute for Pb(2) Pb(1) and Pb(2) sites. The impact of the symmetry of the crystal field on the site-selective doping of Er3+ is proposed to explain the variation of upconversion luminescence spectrum.
Influence of the growth conditions on the transparent conductive properties of ZnO：Al thin films grown by pulsed laser deposition
Density-density correlation in quasi two-dimensional free expanding Bose-Einstein condensates
The effective Lagrangian density function and the quantum fluctuation of the wave function in the form of quantized operators are presented for a quasi two-dimensional Bose-Einstein condensate by means of Madelung transformation. This paper calculates the two-point density-density correlation function of the condensate during its free expansion after its confinement potential is removed. Results show that the two-point density-density correlation function in the long-wave limit is proportional to the wave number k and it tends to be a constant in the short-wave limit.
“Lamellar↔rod” transition mechanism under high growth velocity condition
At a low velocity, the “lamellar↔rod” eutectic transition can be controlled by the volume fraction of one eutectic phase only. The factors which affect this kind of transition at high growth velocities are not clear. Based on the competitive growth rule, the criterion for “lamellar↔rod” transition is obtained by combining the models of lamellar and rod eutectic growth under rapid solidification conditions. It is shown that for a certain volume fraction, if its value fluctuates around the critical point predicted by the JH Jackson and Hunt model, the increase of the growth velocity or the partition coefficient will lead to the “rod→lamellar” transition. Otherwise, no transition will take place. The “lamellar↔rod” eutectic transition at high growth velocity is controlled by the volume fraction variation, which is caused by the increase of the growth velocity.
SiBN ceramics, a stealth material at high temperature
Silicon boron nitride (SiBN) has been paid attention extensively due to its high melting point and anti-oxidation, which is also the reason that one of the research focus is its physical property of this material at high temperatures. It has been reported that amorphous SiBN ceramics could be modeled based on the the atomic structure of β-Si3N4. In this paper, the molecular dynamics and DFT calculation were employed to explore the structural model of SiBN, to reveal the electronic and optical properties of SiBN at high temperatures. It is worth noting that, different from β-Si3N4, the absorption of SiBN at visible light and higher frequency decreases at higher temperatures, and the reflectance decreases to 1% or so. Such results could not be found in single crystalline Si3N4. These indicate the possibility of SiBN used as the stealth coating. It also could be a good candidate in the optoelectronic application of amorphous materials in the near future.
Growth of vanadium dioxide thin films on Pt metal film and the electrically-driven metal–insulator transition characteristics of them
Theoretical study on degradation phenomenon on AlGaN/GaN resonant tunneling diode
Study on the electronic structures of Iridium-doped SmOFeAs under the strongly correlated electrons effects
Analysis of the finite-temperature phase transition of Heisenberg antiferromagnetic compound LiVGe2O6
The susceptibility and nuclear magnetic resonance measurements on quasi-one-dimensional spin-1 Heisenberg antiferromagnet LiVGe2O6 indicate that this material shows a phase transition from paramagnetic state to antiferromagnetic Néel state at about 22 K, and there exists a gap in the low-temperature magnetic excitation spectrum. Based on the model Hamiltonian of LiVGe2O6, we propose a low-energy field theory——Ginzburg-Landau theory for this compound. From this theory, we study the finite-temperature phase transition induced by spontaneous symmetry breaking and then calculate the finite-temperature susceptibility of LiVGe2O6. All the theoretical calculations are consistent with the experimental results.
Study on cryogenic remanence measurement technology for chunk permanent magnet
Investigation of magnetic properties of FeCoAlON thin films with stripe domain structure
Study on preparation and characteristics of Fe- and Mn-doped AlN thin films
Phase field crystal study on grain boundary evolution and its micro-mechanism under various symmetry
Phase field crystal method is used to investigate the deformation process and mechanism of twined structure of a trigonal phase under uniaxial tensile deformation, and the evolution and corresponding micro-mechanism of low-angle symmetric and asymmetric grain boundaries (GB) as well as high-angle symmetric and asymmetric GB during deformation process are analyzed in detail. The deformation is performed under the condition that the direction of applied stress is parallel to that of initial GB. Results show that low-angle symmetric GB is composed of two kinds of edge dislocations with the angle made by Burgers vectors being around 60° During deformation, two kinds of dislocations in low-angle symmetric GB move along two opposite directions, then meet with the same kind of dislocation emitted from another GB leading to the annihilation of partial dislocations. As to the low-angle asymmetric GB, its only one kind of dislocation first climbs and moves along the horizontal direction of the applied stress, then each dislocation will break down into two dislocations with their Burgers vectors making an angle about 120°, finally a perfect single crystal is formed via the movement and annihilation of dislocations. High-angle GBs first keep horizontal shape under the applied stress, then become serrated, and the dislocations are emitted from the cusps in GBs. Finally, the high-angle asymmetric GB will decompose with the movement and annihilation of dislocation, while the shape of high-angle symmetric GB becomes horizontal again. It can be seen that the high-angle symmetric GB is more stable than the high-angle asymmetric GB; this is in agreement with the results of experiments and molecular dynamics.
Relationships between synthesizing parameters, morphology, and contact angles of ZnO nanowire films
Influence of pulling velocity on microstructure and morphologies of SCN-DC eutectic alloy
Equivalent circuit analysis model of charge-controlled memristor and its circuit characteristics
Study on control pulse combination of pulse train controlled switching converter and its multi-periodicity analysis
Dynamical modeling and multi-period behavior analysis of voltage-mode bi-frequency controlled switching converter
Mechanism of instability behaviors and stabilization on V2 controlled buck converter
An improved back projection imaging algorithm for dechirped missile-borne SAR
Noise characterization of quantum dot infrared photodetectors
Study on physical model for strained Si MOSFET with hetero-polycrystalline SiGe gate
The investigation of LED degradation model based on the chemical kinetics
Macrotransport analysis of effective mobility of biomolecules in periodic nano-filter polar arrays
Micromagnetic analysis of the maghemite platelet chains in the iron-mineral-based magnetoreceptor of birds
Robust observer-based H∞ control for nonlinear T-S fuzzy time-delay systems
This paper considers the design problem of observer-based H∞ output feedback control over the nonlinear Takagi-Sugeno (T-S) fuzzy systems with distributed delays．Firstly, delay-dependent sufficient conditions satisfy the H∞ performance, are given for the stability analysis in terms of non-strict linear matrix inequality; then, the equivalent linear matrix inequality stability conditions can be obtained. Based on this, the solvable of the observer-based H∞ output feedback control problem is proposed. Finally, a numerical example is given to illustrate the effectiveness of the design approach here.
The base scale entropy analysis of fMRI
Well layer design for 1eV absorption band edge of GaInAs/GaNAs super-lattice solar cell
The GaInAs/GaNAs super-lattice with a feature of space separation of In and N constituents as an active region, is one of the most important ways to achieve 1 eV GaInNAs-based solar cells. To experimentally realize the high-quality super-lattice structure with the required band-gap, Kronig-Penney model is used to obtain the barrier thickness dependence on the well thickness and its composition. Meanwhile, the strain state of GaInAs/GaNAs SLs with various well choices is also discussed. Results show that when both the GaNAs and GaInAs act as the well layers the super-lattice can achieve 1 eV band-gap, and when the GaN0.04As0.96 is considered to act as the well layer, the entire GaInAs/GaNAs SLs have smaller strain accumulations as compared with the case of Ga0.7In0.3As as the well layer in the super-lattice structure.
Analysis of voluntary vaccination model based on the node degree information
Coloring the complex networks and its application for immunization strategy
New infinite sequence soliton-like solutions of (2+1)-dimensional generalized Calogero-Bogoyavlenskii-Schiff equation
A modified electromechanical model with one-dimensional abalation model for numerical analysis of the pulsed plasma thruster
Parameter-induced stochastic resonance in multi-frequency weak signal detection with α stable noise
In this paper we combine α stable noise with bistable stochastic resonance to investigate the parameter-induced stochastic resonance in the high-and low-frequency (both for multi-frequency) weak signal detection with different α stable noise, and explore the action laws between the stability index α(0< α ≤ 2) and skewness parameter β(-1≤ β≤ 1) of α stable noise, and the resonance system parameters a, b on the resonant output effect. Results show that for different distribution of α stable noise, the high- and low-frequency weak signal detection can be realized by tuning the system parameters a and b. The intervals of a and b which can induce stochastic resonances are multiple, and do not change with α or β. Moreover, while detecting the high- and low-frequency weak signal, the action laws of the resonant output effect which are affected by α or β are the same. These results will contribute to realize a reasonable selection of parameter-induced stochastic resonance system parameters under α stable noise, and lay the foundation for a practical engineering application of multi-frequency weak signal detection based on the stochastic resonance.
Study on bifurcation and chaos in single-phase H-bridge inverter modulated by unipolar sinusoidal pulse width modulation
The resonant behavior of fractional harmonic oscillator with fluctuating mass
Synchronization, antisynchronization and amplitude death in coupled fractional order bistable oscillators
Chaos control of SEPIC converter based on resonant parametric perturbation method
A dynamic threshold value control method for chaotic neural networks
Vehicle negotiation model and bifurcation dynamic characteristics research
Shock temperature of femtosecond laser ablation of solid target
Study of 2.9 THz quantum cascade laser based on bound-to-continuum transition
Image lag modeling and correction method for flat panel detector in cone-beam CT
Study on P-branch emission spectral lines of AuO molecule using improved analytical formula
Hydrogen storage of Mg-decorated closo-hexaborate B6H62-
Identification of plastics by laser-induced breakdown spectroscopy combined with support vector machine algorithm
A full three-dimensional numerical diagnosis of Japan Atomic Energy Agency 10 Ampere multi-cusp negative hydrogen ion source
Characteristics of lightning radiation source distribution and charge structure of squall line
Interannual and interdecadal atmospheric circulation anomalies of autumn dry/wet over the loess plateau and its multi-scalar correlation to SST