bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of variation in pressure-induced electrode position on the measurement accuracy of sample conductivity in a diamond anvil cell(Retracted Article)
Authors: Wu Bao-Jia  , Han Yong-Hao  , Peng Gang  , Jin Feng-Xi  , Gu Guang-Rui  , Gao Chun-Xiao  ,   College of Science, Yanbian University, Yanji 133002, China;,   State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
Published: December 2020

Using the finite element analysis, we study the effect of variation in pressure-induced electrode position on the measurement accuracy of the sample conductivity in diamond anvil cell with the Van der Pauw method. The results show that the electrode contact placement and electrode size play key roles in influencing the conductivity measurement accuracy. Theoretical computation reveals that the Van der Pauw method can provide an accurate result when the spacing between electrode center and sample periphery b is less than or equal to d/9 (d is the sample diameter). Otherwise, the closer to the sample center of the contact location, the more rapidly the sample conductivity accuracy error increases. Such an effect is more significant for the semiconductor sample with high resistivity with the electrode position variation is the same.
Dielectric spectroscopy of Al2O3-Y2O3-ZrO2 ternary composite ceramics
Authors: Chen Dong-Ge  , Tang Xin-Gui  , Jia Zhen-Hua  , Wu Jun-Bo  , Xiong Hui-Fang  ,   School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou 510006, China
Published: December 2020

Al2O3-Y2O3-ZrO2 ternary composite ceramics are synthesized via the traditional solid state reaction method and sintered at 14001500 ℃. The phase structure, the microstructure and the electrical properties of these samples are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and dielectric spectra. There are not any other impurity phases in this ternary system supported by XRD patterns, and additions of Y2O3 and ZrO2 into Al2O3 make contributions to the lower calcining heat. SEM indicates that the grain sizes of these samples are about 200500 nm. Furthermore, the densities are improved and the grain boundaries are clearer for the samples sintered at higher temperatures. Relaxation peaks are observed in the dielectric loss plots and the relaxation is of non-Debye type according to Cole-Cole complex impedance spectrum.
The pressure wave analysis in high velocity compaction process
Authors: Wang Shuang  , Zheng Zhou-Shun  , Zhou Wen  ,   Institute of Mathematical Sciences and Computing Technology, Central South University, Changsha 410083, China
Published: December 2020

The pressure propagation in high velocity compaction process is simulated based on the discrete element method in this paper. Because the full process is divided into elastic loading, plastic deformation and elastic unloading, the governing equations are established in three stages respectively. With the help of computing software PFC2D, the impacting force through different layers of powders can be obtained, which cannot be observed in experiment. The simulation results show obviously a delay phenomenon and serrate waves with different gradients in loading and unloading processes. Finally, the simulated low-level stress waves are compared with available experimental data, which are consistent with each other.
The study of interface and photoelectric performance of dye-sensitized solar cells in the applied negative bias
Authors: Chen Shuang-Hong  , Weng Jian  , Wang Li-Jun  , Zhang Chang-Neng  , Huang Yang  , Jiang Nian-Quan  , Dai Song-Yuan  ,   Key Laboratory of Novel Thin Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China;,   College of Physics and Electronic Information Engineering, Wenzhou University, Wenzhou 325035, China
Published: December 2020

Dye-sensitized solar cell (DSC) modules are most likely to work for long time under negative bias due to the mismatch in the outdoor usage, which can obviously influence the cell performance. In this paper, the interface property of DSC under negative bias is investigated by Raman spectroscopy, electrochemical impedance spectroscopy and incident-photon-to-electron conversion efficiency (IPCE). The results of Raman spectroscopy indicate that the decreased peak intensity at 167 cm-1 (the oxidized state of N719 (D+)/ I3-) after 1000 h could be due to Li+ ions diffusing into the TiO2 electrode and partially being intercalated into the TiO2 film. It is also found that the increased recombination resistance in the interface of TiO2/electrolyte resultes in the improved open-circuit voltage and the decreased IPCE values, leading to reduced short-circuit current for DSC with base electrolyte under the long-term negative bias. However, when BI is added into the base electrolyte, the Raman spectrum shows no significant change and that the cell efficiency remains stable after 1000 h. The reason is that BI could prevent Li+ ions from being intercalated into the TiO2 film. It is proven by the further experiments where the DSC with BI exhibits better stability under different negative biases.
Molecular dynamics simulation of promotion mechanism of store hydrogen of clathrate hydrate
Authors: Yan Ke-Feng  , Li Xiao-Sen  , Sun Li-Hua  , Chen Zhao-Yang  , Xia Zhi-Ming  ,   Key Laboratory of Renewable Energy and Natural Gas Hydrate, Guangzhou Center for Gas Hydrate Research,Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;,   Graduate University of Chinese Academy of Sciences, Beijing 100049, China;,   Hulunbeir Vocational and Technology College, Hulunbeir 021008, China
Published: December 2020

Molecular dynamics(MD) simulation is used to study the promotion mechanism of store hydrogen via the hydrate formation. The stable structures and the microcosmic properties of pure H2 hydrate, H2+tetrahydrofuran (THF) hydrate, H2+tetra-n-butylammonium bromide (TBAB) and H2+tetraisoamylammonium bromide (TiAAB) semiclathrate hydrates are investigated systematically. The stabilization energy, EGH, between guest and cavity is calculated. It is shown that the large cavity of hydrate plays a main role of stabilizing hydrate. THF in large cavity can promote the stabilization of hydrogen hydrate and reduce the pressure of formation hydrogen hydrate, which are the same as the experimental results. Compared with the EGH between guest and large cavity, the results are in the order of increase as TiAAB,TBAB,THF,H2. It is concluded that the stability of semiclathrate hydrate is better than the structure Ⅱ hydrate, and H2+TiAAB semiclathrate hydrate is stablest. MD simulation provides helpful information for future TiAAB semiclathrate as a new promoter of forming hydrate and a new hydrogen storage material.
Amplitude control of limit cycle from Hopf bifurcation in the Langford system
Authors: Cui Yan  , Liu Su-Hua  , Ge Xiao-Ling  ,   School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China;,   Vocational Technical College, Shanghai University of Engineering Science, Shanghai 200437, China
Published: December 2020

The control of amplitude of limit cycle emerging from the Hopf bifurcation in Langford system under a nonlinear feedback controller is investigate in this paper. Explicit nonlinear control formulae and amplitude approximations in terms of control gains are derived by utilizing the center manifold theory and normal form reduction. Gain-amplitude curves for controlled systems are drawn and verified by numerical simulations. The formulae and expressions for the Langford system present a convenient approach to obtaining an effective analytical control in this system.
Suppressions of spiral waves and spatiotemporal chaos in cardiac tissue
Authors: Kuang Yu-Lan  , Tang Guo-Ning  ,   College of Physics and Technology, Guangxi Normal University, Guilin 541004, China
Published: December 2020

Suppressions of spiral waves and spatiotemporal chaos in cardiac tissue are investigated by using the Luo-Rudy phase I model. Two control methods are proposed. (Ⅰ) A planar wave is generated by alternately changing the extracellular potassium ion concentration, and then a weak external electric field is used to help plane wave to suppress spiral waves and spatiotemporal chaos. (Ⅱ) The extracellular potassium ion concentration is first enhanced. Planar waves are then generated by the wave emission induced by an external electric field. We use the planar waves to suppress the spiral waves and spatiotemporal chaos. The results show that the control methods can effectively suppress spiral waves and spatiotemporal chaos when relevant parameters are appropriately chosen. When regional myocardial ischemia occurs, high extracellular potassium ion concentration will appear where myocardial ischemia occurs. The methods of wave emission can be used to suppress spiral waves and spatiotemporal chaos in heart in this case. The advantages and mechanism of the control methods are explained.
The study of the interference between pedestrians and vehicles based on cellular automaton model
Authors: Sun Ze  , Jia Bin  , Li Xin-Gang  ,   Key Laboratory for Urban Complex Transportation Systems Theory and Technology of Ministry of Education, School of Traffic and Transportation, Beijing Jiaotong University, Beijing 100044, China
Published: December 2020

Serious interference between motor vehicles and pedestrians happens at crosswalk when pedestrian flow is large. In this paper, cellular automata models are used to model the behavior of mutual interferences between pedestrians and vehicles at crosswalk by introducing conflict interference rules between pedestrians and vehicles. Numerical simulations are carried out to study the fluxes of vehicle and pedestrian, influenced by the parameters, such as the arrival rates, pedestrian waiting time and the pedestrian's sensitivity coefficient to vehicle. Simulation results show that the model can reflect the interference characteristics between pedestrians and vehicles well. With the increase of threshold that pedestrians cross the traffic lane riskily, motor vehicle flow increases but pedestrian flow decreases. With the increase of pedestrian's sensitivity coefficient, pedestrian avoiding probability decreases, motor vehicle flow decreases, pedestrian flow increases. The results have certain significance for the control and management of mixed traffic.
Influence of mechanical configuration and hardness of last stage anvil on high pressure producing efficiency for octahedral cell
Authors: Guan Jun-Wei  , He Duan-Wei  , Wang Hai-Kuo  , Peng Fang  , Xu Chao  , Wang Wen-Dan  , Wang Kai-Xue  , He Kai  ,   Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
Published: December 2020

We analyse the loading force transmissions for two kinds of loading structures directed at multistage octahedral cell of high pressure device, and build a mechanical relationship for high pressure producing efficiency. The relationship between cell pressure and hydraulic load is calibrated at room temperature for 14/8, 12/6 and 10/4 cell assemblies using the phase transitions of Bi, ZnTe, ZnS and GaAs under high pressure. Also we discuss qualitatively the influences of both mechanical configuration and hardness of last stage anvil on high pressure producing efficiency of octahedral cell. The experimental results show that both mechanical configuration and hardness of last stage anvil are key factors for affecting high pressure producing efficiency, what is more, the mechanical configuration is more important. The larger the geometry configuration of octahedral cell, the higher the high pressure producing efficiency is; high pressure producing efficiency of 6-8 type loading configuration is higher than that of 2-6-8 type loading configuration; when the pressure of octahedral cell approaches to Vickers hardness of last stage anvil, the harder the last stage anvil, the higher the high pressure producing efficiency and the higher cell pressure is.
A theoretical study on electron impact excitation differential cross sections and Stokes parameters of Mg atom
Authors: Liu Li-Juan  , Xie Lu-You  , Chen Zhan-Bin  , Jiang Jun  , Dong Chen-Zhong  ,   Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, China
Published: December 2020

Differential cross sections (DCSs) and Stokes parameters for electron impact excitation of 3s3p 1P1, 3s4p 1P1 states in magnesium are calculated by using the fully relativistic distorted-wave (RDW) program REIE06. In the calculations, the relativistic effects and electron correlations are considered systematically. The results are analyzed and compared with available experimental data and theoretical calculations, and they are in good agreement with each other.
Analysis of digital in-line polarization holography by Stokes parameters
Authors: Chen Ping  , Tang Zhi-Lie  , Wang Juan  , Fu Xiao-Di  , Chen Fei-Hu  ,   School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China;,   Laboratory of Quantum Information Technology, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
Published: December 2020

A new method of polarization imaging, based on Stokes parameter, is proposed by digital in-line holography. The idea is to reconstruct the spatial distribution of polarization state of light transmitted through anisotropic objects using a linearly polarized beam and an elliptically polarized reference beam. Stokes parameters of object wave are obtained and the distribution of polarization can be determined uniquely by obtaining digital holograms in both orthogonal orientations and measuring the information about amplitude and phase of object wave in these two directions. The results show that the method can be used to measure the polarized properties of objects. In addition, it is applicable to both in-line and off-axis holography, because it can remove a zero-order and conjugate image components while acquiring Stokes parameters of object wave.
The optical transmission and improvement of flux for the static polarization wind imaging interferometer
Authors: Zhang Xuan-Ni  , Zhang Chun-Min  ,   Non-equilibrium Condensed Matter and Quantum Engineering Laboratory, the Key Laboratory of Ministry of Education, School of Science, Xi'an Jiaotong University, Xi'an 710049, China;,   Institute of Physics and Electronic Engineering, Xianyang Normal University 712000, China
Published: December 2020

The static polarization wind imaging interferometer takes advantage of polarized-light beam to obtain interferogram, and beam transmission characteristic in core polarization components is a key issue. The Jones matrix is convenient and concise for analyzing the optics polarization state, and easy to obtain the relationship of key optical components in the system performance. The Jones matrix is introduced to describe the static polarization interferometer system respectively in a given case and in a general case. The variations of optical flux and interference fringe visibility are investigated as functions of polarization direction and wave plate azimuth associated with the key components, and their optimal values are ascertained. The optical flux can be improved by widening field of view and increasing the transmittance of the pyramid prism. The simulation results of the interference intensities confirm the theoretical expectations.The study provides a theoretical basis and practical guidance for the design, development and engineer of the static polarization wind imaging interferometer.
Experimental studies of the characteristics of a real-time ion detector-plastic scintillator
Authors: Xu Miao-Hua  , Li Hong-Wei  , Liu Feng  , Liu Bi-Cheng  , Du Fei  , Zhang Lu  , Su Lu-Ning  , Li Ying-Jun  , Li Yu-Tong  , Chen Jia-Er  , Zhang Jie  ,   Department of Physics, China University of Mining and Technology (Beijing), Beijing 100083, China;,   Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China;,   State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China;,   Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China
Published: December 2020

The characteristics of a real-time ion detectorplastic scintillator are experimentally investigated on an electrostatic accelerator. The sensitivity, the dynamic range, the energy response, and the spatial resolution of the plastic scintillator are calibrated, and then compared with those of other ion detectors. Meanwhile, the possibility for the plastic scintillator to be used as a diagnostic tool in laser-driven ion acceleration experiment is discussed. The plastic scintillator provides an efficient tool for online ion detection in the experiments of high-repetition-rate laser-driven ion accelerations.
Influence of the ambient pressure of Ar on the range of nucleation area of Si nanoparticles
Authors: Chu Li-Zhi  , Deng Ze-Chao  , Ding Xue-Cheng  , Zhao Hong-Dong  , Wang Ying-Long  , Fu Guang-Sheng  ,   College of Information Engineering, Hebei University of Technology, Tianjin 300401, China;,   College of Physics Science and Technology, Hebei University, Baoding 071002, China
Published: December 2020

In order to investigate the range of nucleation area of Si nanoparticles under different pressures, a single crystalline Si target with high resistivity is ablated by a XeCl excimer laser (wavelength 308 nm, laser fluence 3 J/cm2) in an ambient pressure range from 1 to 200 Pa of pure Ar gas. The Si nanocrystalline films are systemically deposited on glass or single crystalline Si substrates that are lined up at a distance of 2.0 cm under the ablation point. Raman and X-ray diffraction spectra indicate that the films are nanocrystalline. Scanning electron microscope images of the films show that the ambient pressure effect on the average size and the distributing range of Si nanoparticles on the substrate. According to the method of determining the location of nucleation area, it is found that the range of nucleation area of Si nanoparticles first broadens and then narrows with the increase of ambient pressure. The dynamics is analysed theoretically to explain the results.
Study of the stable components in extended-range forecasting for the coming 1030 days during the snow storm event in January 2008
Authors: Wang Kuo  , Feng Guo-Lin  , Sun Shu-Peng  , Zheng Zhi-Hai  ,   College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China;,   Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing 100081, China
Published: December 2020

In this paper we extract components in extended-range forecast for the coming 10-30 days by the Butterworth Band-pass filter using the NCEP/NCAR reanalysis daily data of geopotential height from 1978 to 2007 and from January 6th to February 4th, and at the same time extract the basic function of climate state by empirical orthogonal function (EOF). And we use the same way to deal with the daily data of geopotential height during the snow storm event in January 2008 by the Butterworth Band-pass Filter. We use the contribution rate to explain the variance of EOF and the elements which influence this weather process in a period of 1030 days. Stable components in extended-range forecast for the coming 1030 days can be divided into two parts according to the contribution rate analysis: climatic stable components and abnormal stable components. Results show that climatic stable components are in the subject status during the snow storm event in January 2008 while abnormal stable components are equivalent to a disturbed value superimposed on climatic stable components. The influence of abnormal stable components cannot be neglected, and they can play quite a significant role. The circulation patterns of abnormal stable components correspond well to anomalies in Pacific region. These conclusions deepen our understanding of 1030 days components and provide a new way to think and solve the problem of extended range forecast for the coming 1030 days.
Stochastic resonance for pulse signal modulated by noise in a single-mode laser system
Authors: Zhang Li  , Yuan Xiu-Hua  , Wu Li  ,   Wuhan National Laboratory for Optoelectronics, College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Published: December 2020

A new model of stochastic resonance, in which the pulse signal is modulated by noise, is established for a single-mode laser system. The corresponding intensity correlation function and the output signal-to-noise ratio of the system are calculated in the linear approximation. The phenomena of stochastic resonance are thoroughly discussed. Results reveal that due to the pulse signal modulated by noise, the single-mode laser exhibits a novel stochastic resonance phenomenon, that is, the optimization or the restraint of output signal-to-noise ratio can be controlled by the adjustment of the pulse signal period T.
Parameter estimation for chaotic system based on evolution algorithm with hybrid crossover
Authors: Long Wen  , Jiao Jian-Jun  ,   Guizhou Key Laboratory of Economics System Simulation, Guizhou University of Finance and Economics, Guiyang 550004, China;,   School of Mathematics and Statistics, Guizhou University of Finance and Economics, Guiyang 550004, China
Published: December 2020

A hybrid-crossover-based evolution algorithm is proposed to estimate the parameters of chaotic system. Through establishing an appropriate fitness function, the parameter estimation problem is coverted into a multi-dimensional functional optimization problem. In this approach, the individual generation based on good-point-set method is introduced into the evolutionary algorithm initial step, which reinforces the stability and global exploration ability of the evolutionary algorithm. In the evolution process, it not only can be explored to induce the new individuals generated by stochastic hybrid crossover operation to fly into the better subspace, but also can avoid the premature convergence and speed up the convergence. It coordinates the exploitation ability and the exploration ability of algorithm. Numerical simulations on the benchmark function and the Lorenz system are conducted. The results demonstrate the effectiveness of the proposed algorithm, which is shown to be an effective method of parameter estimation for chaotic systems.
Negative refraction in uniaxially chiral medium with optical axis parallel to the interface
Authors: Li Jie  , Dong Jian-Feng  ,   Institute of Optical Fiber Communication and Network Technology, Ningbo University, Ningbo 315211, China
Published: December 2020

The condition to realize the negative refraction in the uniaxially anisotropic chiral medium with an optical axis parallel to the interface has been investigated. The variations of refraction angles of two eigenwaves with the incident angle for different electromagnetic parameters and chirality parameters are also analyzed. The results show that the uniaxially anisotropic chiral medium is easy to realize the negative refraction, even though it has a small chirality parameter. And for the different permittivities, chirality parameters and incident angles, the phase refractive angles of the two eigenwaves in the uniaxially chiral medium are distinctly different. In a peculiar condition, one or two eigenwaves cannot propagate in the medium.
Investigation of the tunable laser of one-dimensional photonic crystal with dye-doped nematic liquid crystal defect layer
Authors: Liu Yong-Jun  , Sun Wei-Min  , Liu Xiao-Qi  , Yao Li-Shuang  , Lu Xing-Hai  , Xuan Li  ,   College of Science, Harbin Engineering University, Harbin 150001, China;,   State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
Published: December 2020

We investigate the optical characteristics of the tunable laser of a one-dimensional photonic crystal (1D PC) containing Dye-doped nematic liquid crystal (NLC). The dielectric multilayer consisting of an alternating stack of SiO2 and TiO2 layers is used as the 1D PC whose defect layer is filled with the laser dye and NLC. The central wavelength of the stop band of the 1D PC is 650 nm. A second-harmonic light of a Q-switched Nd: YAG laser has a wavelength of 532 nm, and is used for excitation. With the temperature increasing from 25.5 ℃ to 48 ℃, the emission wavelength of the tunable laser is continuously shifted from 605.5 to 639.8 nm, the total wavelength shifts is 34.4 nm. With the external voltage increasing from 0 to 2.86 V, the emission wavelength of the tunable laser is shifted from 634.5 to 619.5 nm, the total wavelength shifts are 15 nm. The lasing threshold was about 12.3 J/pulse, and the linewidth of the emission peak was less than 1 nm.
Study on the machining mechanism of fabrication of micro channels in fused silica substrates by laser-induced plasma
Authors: Li Shi-Xiong  , Bai Zhong-Chen  , Huang Zheng  , Zhang Xin  , Qin Shui-Jie  , Mao Wen-Xue  ,   Key Laboratory of Photoelectron Technology and Application, Guizhou University, Guiyang 550025, China
Published: December 2020

A Q-switched Nd: YAG laser was used to fabricate micro channels in the fused silica substrate by laser-induced plasma. The micro channels were observed with fluorescence microscope, no thermal cracks around the channels and the depth of the channels is up to 4 mm. There are coagulation layers around the inner surface. We studied the ionization mechanism of optical breakdown in solids by nanosecond laser pulses. For the 1064 nm laser, as the intensity of nanosecond pulse is not enough large, plasma formation in optical breakdown is the result of an electron avalanche process. We got the plasma formation model using the breakdown threshold of avalanche ionization and calculated the range of laser plasma based on the model. The theoretical analysis based on the model is shown to be mainly agreement with the experimental observations. The laser-supported detonation wave (LSDW) based on the principle of hydrodynamics was analyzed as well and calculated the characteristic parameters of plasma including the plasma temperature, pressure and velocity. The characteristics of micro channels were analyzed through the parameters. When the plasma passed, the melting quartz solidified with the effect of LSDW and produced the coagulation layers. The ablation of the high temperature and pressure plasma lead to a micro channel of high quality with a relatively smooth internal surface and no thermal cracks.
Magnetoconductance effect in organic light-emitting devices
Authors: Zhang Yong  , Liu Ya-Li  , Jiao Wei  , Chen Lin  , Xiong Zu-Hong  ,   School of Physical Science and Technology, Southwest University, Chongqing 400715, China
Published: December 2020

Organic light-emitting diode (OLED) based on tris-(8-hydroxyquinoline) aluminum(III) (Alq3) is fabricated, and its magnetoconductance (MC) effects are measured at different bias voltages. When the bias voltage is small, the OLED exhibits apparently a negative MC effect. After the bias voltage is increased, the MC value changes from negative to positive, displaying a negative-positive inversion. The MC effects in N, N'-Di(naphthalen-1-yl)-N, N' diphenyl-benzidine (NPB) and Copper phthalocyanine (CuPc) unipolar devices show that the negative MC effect in OLED comes from the CuPc layer in device. The MC effect of bipolar current can be explained using the electron-hole pair model. The MC effect of unipolar current can be attributed to the polaron-bipolaron transition in device. The positive-negative MC inversion in OLED results from the simultaneous contributions of the above two mechanisms during the variation of the injection current.
Coupling characteristics of point defect modes in two-dimensional magnonic crystals
Authors: Cao Yong-Jun  , Tan Wei  , Liu Yan  ,   College of Physics and Electronic Information, Inner Mongolia Normal University, Huhhot 010022, China
Published: December 2020

Using the plane-wave expansion method under supercell approximation, band structures of spin waves propagating in two-dimensional magnonic crystals with coupling multi-point defects and magnetization field distributions of some defect modes are calculated. The results indicate that the energies of point defect modes can couple each other, and propagate along the direction of the multi-point defects in these structures. Utilizing the coupling characteristics of defect modes, two-dimensional magnonic crystals can be used as the fabricating materials of spin-wave waveguides.
Luminescent properties and energy transfer in MAl12O19: Eu2+, Cr3+ (M = Ca, Sr, Ba)
Authors: Zhong Rui-Xia  , Zhang Jia-Hua  , Li Ming-Ya  , Wang Xiao-Qiang  ,   Department of Materials Science and Engineering, Northeastern University at Qinhuangdao Branch, Qinhuangdao 066004, China;,   Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
Published: December 2020

We synthesize MAl12O19 (M = Ca, Sr, Ba) singly doped with Eu2+ or Cr3+ and co-doped with Eu2+ and Cr3+ by high-temperature solid-state reaction under reducing atmosphere. It is observed that there exit energy transfers from Eu2+ to Cr3+ in MAl12O19 (M = Ca, Sr, Ba) hosts. Although the MAl12O19 (M= Ca, Sr, Ba) hosts have similar crystal structures, the energy transfer efficienies and the conversion rates of the blue light to the red light are different. Both experiment and calculation show that the energy transfer from Eu to Cr in CaAl12O19 host is most efficient, and the ratio of the red emission to the blue emission in CaAl12O19 host is the highest among the three different hosts.
Basic properties and applications of the memristor circuit
Authors: Song De-Hua  , Lü Meng-Fei  , Ren Xiang  , Li Meng-Meng  , Zu Yun-Xiao  ,   School of Information and Telecommunication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China;,   School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China
Published: December 2020

The circuits of memristor with border constraint, connected with capacitance and inductance in series, and with capacitance and inductance in parallel are studied separately. The properties of the circuits and the influences of frequency and element parameters on circuit are analyzed. Theories are proved by simulation. Potential applications are predicted based on the properties of memristor with border constraint and its related circuits.
Entropy exchange and entanglement in the multi-photon J-C model of a moving atom
Authors: Hu Yao-Hua  ,   Physics and Information Engineering College, Luoyang Normal College, Luoyang 471022, China
Published: December 2020

Considering a moving two-level atom interacting with a single-mode thermal field through multi-photon process, in this paper we study the entropy exchange between the atom and the field by using quantum partial entropy and entanglement measured by using Concurrence, and investigate the effects of the initial atomic state, the atomic motion, the mean photon number and the transition photon number on entropy and entanglement. The results show that the entropy exchange and the entanglement exhibit the periodic evolution due to atomic motion, and entropy exchange occurs. The entanglement between the atom and the field is strengthened as the transition photon number increases. When the partial entropy exchange between atom and field is zero, the entanglement is also zero.
Study on gravitational waveform from post-Newtonian orbits of spinning compact binary
Authors: Zhong Shuang-Ying  , Liu Song  ,   School of Sciences, Nanchang University, Nanchang Jiangxi 330031, China
Published: December 2020

The purpose of this paper is to investigate the effects of the dynamical parameters, the spin-orbit coupling, the spin-spin coupling and the classification of orbits on the gravitational waveforms emitted by the conservative post-Newtonian Hamiltonian system for the spinning compact binaries by means of symplectic integrator and power spectrum. The numerical results show that the gravitational waveforms of ordered orbits vary periodically with time, while those of chaotic orbits are stochastic under the radiation--reaction force turning off. In particular, the chaotic dynamic behavior can enhance the strength of emission power. In addition, the magnitude of the spin parameter does exert a significant influence on the gravitational waveforms.
Effect of noises on the stability of a metapopulation
Authors: Wang Can-Jun  , Li Jiang-Cheng  , Mei Dong-Cheng  ,   Nonlinear Research Institute, Baoji University of Arts and Sciences, Baoji 721016, China;,   Department of physics, Yunnan University, Kunming 650091, China
Published: December 2020

The Levins model subjected to the noise is employed to study the stability of a metapopulation. The analytic expressions of the stationary probability distribution function and the mean extinction time of the metapopulation are obtained according to the Fokker-Planck Equation. The results show that for the case of no correlation between the additive noise and the multiplicative noise (=0, is the intensity of correlation between multiplicative and additive noise), the increase of the additive noise intensity weakens the stability of a metapopulation; for the case of 0, enhances the stability of a metapopulation. For -(c-e-D)2/(4cD)1, can induce the resonance restrain phenomenon. Meantime, there exists a critical value of D. When D is lower than the critical value, the stability of the system is enhanced.
Design and simulation of a single-sided left-handed material in THz regime
Authors: Li Jun-Cheng  , Guo Li-Xin  , Liu Song-Hua  ,   School of Science, Xidian University, Xi’an 710071, China
Published: December 2020

By retrieving the constitutive effective parameters of bifilar spiral structure, it is proved that its permittivity and permeability are negative at different frequencies. With the electromagnetic waves incidence in the direction either perpendicular or parallel to the surface of bifilar spiral structure, it is found that the causes of negative permittivity are the same. Previously the investigation of single-sided left-handed materials was limited to microwave band. Through modifying bifilar spiral metamaterials, we design a new single-sided left-handed material in the terahertz regime and the design principle is explained with an LC equivalent circuit. The left-handed material generally consists of electric and magnetic resonators etched on each side of the dielectric substrate respectively Compared with these composite structures, the new single-sided left-handed material has the advantages of low loss, simple structure and easy operating
Experimental research of triangular optical pulse generation in normal dispersive fiber
Authors: Wang Hua  ,   Centre of Information and Communications, Jiangxi Electric Power Corporation, State Grid, Nanchang 330077, China
Published: December 2020

Generation of triangular optical pulses in conventional normal dispersive (ND) fiber is experimentally realized using a passive nonlinear pulse shaping method based on a combination of pulse pre-chirping, group-velocity dispersion and self-phase modulation in a section of ND fiber. It is found that by optimizing the parameters of launching pulse power level and ND fiber length, high-quality triangular optical pulses with nearly constant gradients of leading and trailing edges and linear frequency chirp profiles can be obtained for a wide range of different pulse pre-chirping values. For different pulse pre-chirpings, high launch power is required for triangular optical pulse generation. The tolerance of triangular pulse formation to ND fiber length and launch power level is improved with the increase of pulse pre-chirping, which means that it is easy to obtain triangular pulses for higher pulse pre-chirping.
Key technology on all-plastic optical life detection instrument
Authors: Kong De-Peng  ,  Wang Jin-Meng  ,  Wang Li-Li  , He Zheng-Quan  , Li Yu-Lin  , Dou Zhi-Zhong  ,   State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences. Xi’an 710119, China;,   Graduate University of Chinese Academy of Science, Beijing 100049, China
Published: December 2020

Plastic fiber image bundle with 250 single fiber diameter, 4096 pixels, 15 m length is fabricated. The result indicates that 25% of the input image remains after it has translated though the 15m fiber bundle, which can meet the need of eye observation or CCD image capture. Based on the key component of image bundle, the eye observation life detection instrument prototype and intelligent life detection instrument prototype connected with CCD, image capture card and portable computer are designed and produced. The effectiveness of researching and rescuing the person from danger is demonstrated. The system can be used not only for researching and rescuing the buried person, but also for video monitoring some special occasions, such as strong electromagnetic interference environment, security department and explosive places.
Ultraviolet light-enhanced field electron emission of zinc oxide nanowires
Authors: Zhang Jin-Ling  , Lü Ying-Hua  , La Dong-Sheng  , Liao Lei  , Bai Xue-Dong  ,   School of Electronic Engineering Beijing University of Posts and Telecommunications, Beijing 100876, China;,   Beijing National Laboratory for condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Published: December 2020

One-dimensional nanomaterial possesses an electric field reinforcing effect, and its field emission properties have aroused much interest. In this paper, ZnO nanowire (NW) arrays are prepared by the thermal chemical vapor deposition (CVD) method, and the characteristic of field electron emission of ZnO NW arrays under the illumination of ultraviolet light is investigated. It is found that, upon ultraviolet light illumination, the turn-on voltage drops off and emission current increases. A process of field emission coupled with semiconducting properties of ZnO NWs is proposed. Ultraviolet photon-excited electron transition from valence band to conductance band and defect energy levels of ZnO NWs can lead the number of emitting electrons to increase, and the photoemission reduces the effective work function of zinc oxide emitters, which largely enhances the field emission performance. The characteristic of field emission of ZnO NWs under ultraviolet light illumination suggests an approach to tuning field emission of semiconductor emitters, which is promising for the applications in optical sensor, cold-cathode flat panel display and field electron source.
Effect of surface potential barrier on quantum efficiency decay of reflection-mode GaN photocathode
Authors: Yang Yong-Fu  , Fu Rong-Guo  , Ma Li  , Wang Xiao-Hui  , Zhang Yi-Jun  ,   Institute of Electronic Engineering and Optoelectronic Technology, Nanjing University of Science & Technology, Nanjing 210094, China
Published: December 2020

Quantum efficiency decay of reflection-mode GaN photocathode is small at short wavelengths and large at long wavelengths. In light of this experimental phenomenon, the emitted electron energy distribution is calculated by using the Boltzmann distribution and transfer matrix method based on Airy function, with the intervalley scattering considered. The effect of surface potential barrier change on quantum efficiency decay is investigated. The results of theoretical calculation are in good agreement with the experiments al results. The reduction of effective dipole in activated layer leads to inereased length and height of surface barrier, which causes more decay of the emitted electron energy distribution generated by longer wavelength photons, and less decay of the emitted electron energy distribution generated by shorter wavelength photons. It is the fundamental reason of phenomenon that the decay of quantum efficiency is small at short wavelengths and large at long wavelengths.
The normalized KLD coefficient and its application in detection of correlation and synchronization from multivariable series
Authors: Xie Xiao-Ping  , Chen Hong-Ping  , Cao Zhi-Tong  , He Guo-Guang  ,   Department of Physics, Zhejiang University, Hangzhou 310027, China
Published: December 2020

The KLD coefficient and the normalized KLD coefficient are proposed to characterize the correlation of multivariable series in order to overcome the intrinsic limitations of the KLD dimension density. Using the uncorrelated or perfectly correlated multivariable series, the upper and the lower bound functions of the KLD dimension density, and furthermore the upper and the lower bounds of the KLD coefficient are analytically deduced. Then, the normalized KLD coefficient is proposed in the paper. The analyses and numerical simulations prove that the changes of correlation of multivariable series can lead to linear variation of the normalized KLD coefficient. The simulations also prove that the normalized KLD coefficient can detect the changes of correlation sensitively, even if these are induced by only two channels of multivariable series. Furthermore, the normalized KLD coefficient can be used to analyze the nonstationary time series. The simulation results of coupled map lattice prove that the normalized KLD coefficient can also be used for the nonlinear system analysis.
Amplitude spiral wave in coupled complex Ginzburg-Landau equation
Authors: Gao Ji-Hua  , Xie Wei-Miao  , Gao Jia-Zhen  , Yang Hai-Peng  , Ge Zao-Chuan  ,   Key Laboratory of Special Functional Materials of Shenzhen, College of Materials, Shenzhen University, Shenzhen 518060, China
Published: December 2020

A novel amplitude spiral wave in coupled complex Ginzburg-Landau equation (CGLE) system is proposed. The stability conditions and the relevant factors are investigated via numerical simulations. On the tip of an amplitude spiral wave there exist no topological defect, which is different from the commonly observed phase spiral wave, and in its amplitude part (instead of phase part) there is a spiral structure. In this research, the stability of amplitude spiral wave is studied by considering the different initial patterns in the case of the system parameter mismatches.
Research on simultaneous reconstruction of the temperature distribution of a 3D participating medium and its boundary
Authors: Feng Yu-Xiao  , Huang Qun-Xing  , Liang Jun-Hui  , Wang Fei  , Yan Jian-Hua  , Chi Yong  ,   State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
Published: December 2020

In-situ and nonintrusive 3D temperature measurement is very important for combustion diagnosis and controlling of pollutants. The temperature reconstruction technique based on radiation inverse analysis has received intensive attention. In order to reduce the computation cost and take boundary temperature into consideration, a discrete method is presented for 3D temperature distribution determination for an absorbing, emitting and scattering combustion medium and its boundary by using the emission image measured by four CCD cameras. First the radiative source term is retrieved through the discrete transfer method. Then, the temperature is inferred from the blackbody intensity obtained by subtracting the media scattering and boundary reflecting contribution from the source term by the discrete ordinate approximation. The least squares minimum residual algorithm is improved to solve the ill-posed reconstruction equations. The performance of the proposed method is examined by numerical test. The effects of measurement noise and radiative properties on the reconstruction accuracy are investigated. The results show that the method proposed in this paper is capable of reproducing the temperature of the medium and its boundary accurately, even with noise. The reconstruction time cost is reduced significantly compared with those of other methods.
Elecrohydrodynamical characteristics of liquid film motor driven by a square-wave electrophoresis electric field
Authors: Liu Zhong-Qiang  , Gan Kong-Yin  , Li Ying-Jun  , Jiang Su-Rong  ,   State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083, China;,   Qindao College, Qingdao Technological University, Qingdao 266106, China
Published: December 2020

Liquid film motor as a novel experimental device will play an important role in basic research and technology applications. In-depth theoretical studies on its electro-hydrodynamics (EHD) motions under various conditions are of great significance. In current paper, the dynamical characteristics of the liquid film motor driven by a square-wave electrophoresis electric field perpendicular to a uniform constant external electric field are investigated. Space-time dependence of the film's rotation linear velocity is derived analytically. The theoretical results indicate that a symmetrical reciprocating rotation in the film gradually converts to a vibration as the frequency of the electrophoresis electric field increases. This not only helps us understand the physical origin of the vibration of the liquid film motor, but also provides a new option to design a liquid film mixer in the application.
Geometric structures and nitrogen adsorption properties of BaO adlayer on Ru(0001) surface
Authors: Zhao Xin-Xin  , Tao Xiang-Ming  , Mi Yi-Ming  , Ji Xin  , Wang Li-Li  , Wu Jian-Bao  , Tan Ming-Qiu  ,   School of Fundamental Studies, Shanghai University of Engineering Science, Shanghai 201620, China;,   Department of Physics, Zhejiang University, Hangzhou 310027, China
Published: December 2020

First principles calculations are performed to study the geometric structures and the nitrogen adsorption properties of BaO adlayer on Ru(0001) surface. It is suggested that BaO adlayer is more stable on Ru(0001) surface at low coverage. A configuration is observed in surface phase at low coverage. In this structure oxygen is adsorbed on the hcp site of one p(1 1) cell, and barium is adsorbed close to the top site of the same p(1 1) cell. Bond length of oxygen and ruthenium is calculated to be 0.209 nm, longer than the EXAFS experimental value about 0.018 nm. Nitrogen prefers to be adsorbed on the sites close to barium. Nitrogen adsorption energies at those sites are calculated to be in a range from 0.70 to 0.87 eV, which are bigger than those at the sites close to oxygen. Adsorption sites near barium atoms have more activities to weaken nitrogen. The lowest N-N stretching vibrational frequency on the sites is about 1946 cm-1, less than the highest frequency on sites around oxygen (about 130 cm- 1). Bond strengths of nitrogen on Ru(0001) /BaO surface are between those on clean Ru(0001) and Ru(0001) /Ba surface. The adsorption properties of sites around BaO layer are determined by chemical characteristic of barium and oxygen. Electron transfer from barium to ruthenium enhances the hybridization between ruthenium and nitrogen by reducing and increasing the occupation of * and * orbitals respectively.
Large-deviation analysis for counting statistics in double-dot Aharonov-Bohm interferometer
Authors: Li Jun  , Liu Yu  , Ping Jing  , Ye Yin  , Li Xin-Qi  ,   State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;,   Department of Physics, Beijing Normal University, Beijing 100875, China
Published: December 2020

The Coulomb correlation and quantum coherence in a double-dot Aharonov-Bohm interferometer can result in two distinct transport channels: a fast channel and a slow one, while their coupling is tunable by changing the magnetic flux passing through an interference loop. However, these effects cannot be manifested by the conventional transport current. In this work, employing the large-deviation method which was originally developed in the nonequilibrium statistical mechanics, we perform a large-deviation analysis for the transport through this double-dot interferometer system and reveal a clear dynamical phase transition behavior.