bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic evolution of composite coherence vortices by superimpositions of partially coherent hyperbolic-sine-Gaussian vortex beams in non-Kolmogorov atmospheric turbulence
Authors: He Xue-Mei  , Lü Bai-Da  ,   Institute of Laser Physics and Chemistry, Sichuan University, Chengdu 610064, China
Published: December 2020

Some experiments show that the practical atmosphere deviates from ideal Kolmogorov model. In this paper, based on the extended Huygens-Fresnel principle and the non-Kolmogorov turbulence model proposed by Toselli et al., the analytical expression for the propagation of partially coherent hyperbolic-sine-Gaussian vortex beams through non-Kolmogorov atmospheric turbulence is derived and used to study the dynamic evolutions of composite coherence vortices formed by coherent and incoherent superpositions of two partially coherent hyperbolic-sine-Gaussian vortex beams in non-Kolmogorov atmospheric turbulence. It is shown that the evolution process of the average intensity of the superimposed beam depends on the general exponent of the non-Kolmogorov turbulence, the sign of the topological charge of the superimposed vortex beam in the source plane, and superposition scheme. The motion, the creation and the annihilation of composite coherence vortices may take place upon propagation through non-Kolmogorov turbulence, and the general exponent , sign of the topological charge and superposition scheme affect the evolution behavior. Finally, the results are compared with those of the previous work.
Study of the optical properties of superlattices ZnO doped with indium
Authors: Feng Xian-Yang  , Lu Yao  , Jiang Lei  , Zhang Guo-Lian  , Zhang Chang-Wen  , Wang Pei-Ji  ,   School of Physics University of Jinan, Jinan 250022, China
Published: December 2020

According to the full-potential linearized augmented plane wave method, we calculate the optical properties of In-doped superlattices ZnO. The results reveal that the Fermi energy level enters into the conduction band after doping In. Dielectric function, absorption, refractive index, reflectivity are found to each have a new transition peak near the Fermi energy level. With the increase of the concentration, this transition peak shifts toward the low energy and the spectrum of the peak is the biggest for the two-layer doping case. The optical absorption edge decreases with the increase of doping concentration. Compared with In-doped ZnO supercell, ZnO superlattice has a high transmissivity in the visible light range.
Parameter optimization of cognitive engine based on chaos multi-objective immune algorithm
Authors: Chai Zheng-Yi  , Chen Liang  , Zhu Si-Feng  ,   School of Information Science and Engineering, Henan University of Technology, Zhengzhou 450001, China;,   School of Computer Science and Technology, Xidian University, Xi'an 710071, China
Published: December 2020

Reasonable setting of engine parameters can improve the performance of the spectrum use. By analyzing engine parameter adjustment of cognitive wireless network, the mathematical model is given, and then it is converted into a multi-objective optimization problem. A chaos multi-objective immune algorithm is proposed to solve the problem. Logistic mapping is used to initialize population and search for the best solutions in every generation. The operators of cloning and antibodies updating are designed, which ensures that the distribution of Pateto optimal solutions is more diverse and uniform. Finally, the simulation experiments are done to test the algorithm under multi-carrier system. The results show that the algorithm can adjust transmission power and modulation mode according to the change of channel and user demands. More solutions with preferences are obtained, so it meets the demands for parameter optimization of cognitive engine.
Evaluation of noninductive charging mechanisms and simulation of charge characteristic structure in the early thunderstorm based on RAMS V6.0
Authors: Li Wan-Li  , Liu Dong-Xia  , Qie Xiu-Shu  , Fu Shen-Ming  , Duan Shu  , Chen Yi-Chen  ,   Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences,Beijing 100029, China;,   International Climatic and Environment Sciences Center, Institute of Atmospheric Physics, Chinese Academy of Science, Beijing 100029, China
Published: December 2020

A new regional thunderstorm model, coupled with two primary non-inductive electrification mechanisms, namely Takahashi (1978) and Saunders (1991) schemes, is developed based on the newest version of RAMS V6.0. Based on the simulation on a thunderstorm in its early stage which occurred in Beijing, the results show that the total charge distribution is tripolar in both schemes when the electric field reaches breakdown value. The results are in agreement with some observations and results of other model. However, the evolution processes and shapes of cloud charge distribution in the two schemes are different. The result of Takahashi's (1978) scheme produces a tripolar charge distribution in the cloud before the first lightning. The Saunders' (1991) scheme produces a transform from inverted dipole distribution to tripolar charge distribution. This is because they used different experimental conditions: different factors lead to different results. The results from both schemes show that the positive charge carrier at a low level of thunderstorm is rain droplet, the aggregates and graupels are located in high level of thunderstorm, and the charge center distribution of graupels is similar to the distribution of total charge in thunderstorm cloud.
New type infinite sequence exact solutions of the second KdV equation with variable coefficients
Authors: Taogetusang  , Bai Yu-Mei  ,   The College of Mathematical, Inner Mongolia University for Nationalities, Tongliao 028043, China;,   The College of Mathematical Science, Inner Mongolia Normal University, Huhhot 010022, China
Published: December 2020

To construct a number of new infinite sequence exact solutions of nonlinear evolution equations and to study the two characteristics of constructivity and mechanicalness of the first kind of elliptic equation, new types of solutions and the corresponding Bcklund transformation of the equation are presented. Then the second kind of KdV equation with variable coefficients is chosen as a practical example and three kinds of new infinite sequence exact solutions are obtained with the help of symbolic computation system Mathematica, where are included the smooth soliton-like solutions, the infinite sequence peak soliton solutions, and the infinite sequence compact soliton solutions. The method can be used to search for new infinite sequence exact solutions of other nonlinear evolution equations with variable coefficients.
Research on the improvement of quantum potential well-based particle swarm optimization algorithm
Authors: Li Pan-Chi  , Wang Hai-Ying  , Song Kao-Ping  , Yang Er-Long  ,   Post-doctoral Research Center of Oil and Gas Engineering, Northeast Petroleum University, Daqing 163318, China;,   School of Computer and Information Technology, Northeast Petroleum University, Daqing 163318, China
Published: December 2020

To enhance the optimization ability of quantum potential well-based particle swarm optimization algorithm, the improved quantum potential well-based particle swarm optimization algorithms are proposed by analyzing the design process of current quantum potential well-based particle swarm optimization algorithms. Firstly, three improved quantum particle swarm optimization algorithms are proposed based on delta potential well, harmonic oscillator and square potential well, respectively, and then a statistic mean-based control parameter design method is presented for the proposed models. Secondly, to highlight the guiding role of the global optimal particle in designing potential well centers, two strategies are presented based on a weighted average of all self-optimal particles and dynamic random variables. The experimental results show that the performances of three improved algorithms are relatively close, the model based delta potential well are slightly better than the other two kinds of model, and the performances of three improved algorithms are superior to that of the original algorithm.
Noise-level estimation of noisy chaotic time series based on the invariant of the largest Lyapunov exponent
Authors: Yao Tian-Liang  , Liu Hai-Feng  , Xu Jian-Liang  , Li Wei-Feng  ,   Key Laboratory of Coal Gasification, Ministry of Education, East China University of Science and Technology, Shanghai 200237, China
Published: December 2020

A novel method of estimating the noise level from a noisy chaotic time series based on the invariant of the largest Lyapunov exponent is presented in this paper. The influence of noise on the distance between two points in an embedding phase space is considered, and then based on the invariant of the largest Lyapunov exponent in a different dimensional embedding phase space, the algorithm is proposed to estimate the noise level. Simulation results show that the estimated values of noise level agree well with the true values when the noise level is less than 10%. And this method is not sensitive to the distribution of noise. Therefore, the method is useful for estimating the noise level of noisy chaotic time series.
Incoherent broadband cavity enhanced absorption spectroscopy for trace gases detection and aerosol extinction measurement
Authors: Dong Mei-Li  , Zhao Wei-Xiong  , Cheng Yue  , Hu Chang-Jin  , Gu Xue-Jun  , Zhang Wei-Jun  ,   Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China
Published: December 2020

We report on the development of incoherent broadband cavity enhanced absorption spectroscopy system based on a short arc Xenon lamp for trace gas detection and aerosol optical properties measurements. A minimum detection sensitivity of 1.8 10-7cm-1 (1, 0.12 s integrating time, and 50 times average) is obtained on the basis of absorption spectroscopy of NO2 in a spectral range of 520560 nm, which corresponds to a minimum detection concentration of ～33 nmol/mol for NO2. Combining a laboratory aerosol generation system, the extinction coefficients of 600 nm diameter monodispersed ammonium sulfate aerosol are measured under different particle concentrations. A cross-section of 1.12 10-8cm2 for ammonium sulfate at 532 nm wavelength is obtained, which agree well with the literature result of 1.167 10-8cm2. The results demonstrate the ability of our system to quantitativly measure aerosol optical properties.
Scattering of the focused Laguerre-Gaussian beams by a spherical particle
Authors: Zhao Ji-Zhi  , Jiang Yue-Song  , Ou Jun  , Ye Ji-Hai  ,   School of Electronic and Information Engineering, BeiHang University, Beijing 100191, China
Published: December 2020

Scattering of the focused Laguerre-Gaussian beams by a spherical particle is performed. According to the generalized Mie theory, the scattering coefficient expressions are gained. From the numerical simulations of the electric field distribution and scattering intensity of the focused Laguerre-Gaussian beams, the scattering intensities are discussed for different scattering angles, radii of spherical particles and topology changes, and the oscillatory behavior of the scattered intensity distribution is explained by the scattering coefficients. The results show that in the focused Laguerre-Gaussian beams, the backscattering intensity increases with the particle radius; and the particle radius when the scattering intensity begins to increase is related to the topological charge. Comparing with the Gaussian beams, we can see that the focuced Laguerre-Gaussian beams have different the scattering characteristics, so they have potential value for particle size measurement, optical communication, atmospheric backscattering detection, etc.
One- and two-mode successively squeezed state and its statistical properties
Authors: Yuan Hong-Chun  , Xu Xue-Xiang  ,   College of Optoelectronic Engineering, Changzhou Institute of Technology, Changzhou 213002, China;,   College of Physics and Communication Electronics, Jiangxi Normal University, Nanchang 330022, China
Published: December 2020

One- and two-mode successively squeezed state, obtained through re-squeezing two single mode squeezed states by the two-mode squeezing operator, is studied in terms of the technique of integration within an ordered product (IWOP) of operators. We first derive the normally ordered form of this one- and two-mode successively squeezing operator, and then investigate the quantum statistical properties of the corresponding squeezed state. Particularly, we use the Weyl ordering invariance under a similar transformation to derive the analytical expression of its Wigner function, which seems very easy and concise. Finally, the experimental generation of one- and two-mode successively squeezed state is also proposed simply.
Numerical study of flow field characteristics for triplet impingement injector and combustor
Authors: Jin Dong-Huan  , Liu Wen-Guang  , Chen Xing  , Lu Qi-Sheng  , Zhao Yi-Jun  ,   College of Opto-Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China
Published: December 2020

The chemical reactions in combustor are described by integrating Eddy-Dissipation Model with Arrhenius rate coefficients. The cold and react flow fields of triplet impingement injector and combustor are simulated using the three-dimensional computational fluid dynamics method. Both helicity and mixing length are introduced to study the mixing mechanism and the effect of triplet impingement injector. The key characteristic parameters of combustor, e.g., spatial distributions of total temperature and pressure, residence time of gas flow in combustor, are obtained. The flow field characteristics of triplet impingement injector and combustor for Fuel-Oxidizer-Fuel (F-O-F) and Oxidizer-Fuel-Oxidizer (O-F-O) triplet arrangements are analyzed. The degree of F2 dissociation in combustor exit plane for O-F-O triplet arrangement is 13.5% higher than that for the F-O-F triplet arrangement under conditions of specified composition proportioning and combustor characteristic length. Experimental result demonstrates that the output power of laser is increased by 17%.
High power polarization-maintaining master oscillator power amplifier fiber laser in all-fiber format
Authors: Dong Xiao-Lin  , Xiao Hu  , Ma Yan-Xing  , Zhou Pu  , Guo Shao-Feng  ,   College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, China
Published: December 2020

Experimental study on all-fiber polarization maintaining master oscillator power amplifier fiber laser is performed. A 5 m small core diameter double clad polarization-maintaining Yb-doped fiber is employed in the experiment by means of two-level cascade amplification. A more than 67 W polarization maintaining laser is obtained under a maximal 88 W pump power. In this case, the laser density in the fiber core is about 3.4 W/m2, and the optical-to-optical efficiency is 76%. A higher power laser output can be realized as the pump power is further enhanced.
Experimental study on fractional double-vortex beams
Authors: Fang Gui-Juan  , Sun Shun-Hong  , Pu Ji-Xiong  ,   College of Information Science and Engineering, Huaqiao University, Xiamen 361021, China;,   Department of Physics and Electromechanical Engineering, Sanming University, Sanming 365004, China
Published: December 2020

The generation of fractional vortex beams and their propagation have been interesting research topics in recent years. In this paper we introduce a new type of fractional double-vortex beam, which is generated by the coaxial superposition of the vortex beams with two different fractional topological charges, and its total intensity distribution is of double-ring. We study the generation of this kind of beam theoretically and experimentally. It is shown that the rings of the fractional double-vortex beams carry different orbital angular momenta, from each other and propagate independently. The fractional double-vortex beams possess diverse manipulations as compared with the vortex beams with integer or single fractional charges. Therefore, the fractional double-vortex beam will be of great significance in optical rotation and manipulation of microscopic particles.
Influence of laser passivation on fused silica damage after CO2 laser mitigation
Authors: Li Xi-Bin  , Yuan Xiao-Dong  , He Shao-Bo  , Lü Hai-Bing  , Wang Hai-Jun  , Xiang Xia  , Zheng Wan-Guo  ,   Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China;,   School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
Published: December 2020

A 10.6 m CO2 big size laser beam is used to passivate the ablation deposit on surface of damage site which is repaired with single laser pulse. When the irradiated region is placed on front surface, modulation by 355 nm UV ns laser pulse is inhibited effectively; when the irradiated region is situated on rear surface, the initial damage threshold exceeds the substrate initial damage threshold. Second repair makes the thermal stress distribution enlarged obviously and the thermal stress magnitude weakened. The damage growth examination shows that once thermal stress is released, the initial phase damage growth exhibits an exponential tendency and as shoot number increases the damage size approaches to a constant value.
Numerical investigations on the Schardin's problem
Authors: Sha Sha  , Chen Zhi-Hua  , Zhang Huan-Hao  , Jiang Xiao-Hai  ,   Key Laboratory of Transient Physics, Nanjing University of Science and Technology, Nanjing 210094, China
Published: December 2020

When shock waves passes through a triangle wedge (Schardin's problem), some complicated physical phenomena, including shock wave Mach refection and diffraction, wedge wake, vortexlet, etc. may occur. In this paper, the Schardin's problem is investigated numerically with the combination of the third-order WENO scheme, structured adaptive mesh refinement (AMR) method and immersed boundary method. Our numerical results show clearly the interaction between the incident shock wave and the triangle wedge, the Mach reflection on the wedge surface, its diffraction at the wedge tips, and the induction of the main vortex, which accord excellently with Schardin's experimental and previous numerical results. In addition, our numerical results display in detail the induction process of the vortexlet along the slip layer of the main vortex and the interaction of the shock wave with the vortexlet, and the generation of the serial acoustic waves, which have not been reported in the literature.
The influence of new additive in alkaline solution on the shape of pyramid on the monocrystal Si surface
Authors: Tian Jia-Tong  , Feng Shi-Meng  , Wang Kun-Xia  , Xu Hua-Tian  , Yang Shu-Quan  , Liu Feng  , Huang Jian-Hua  , Pei Jun  ,   Physics Department of Shanghai Jiaotong University, Shanghai 200240, China;,   Shanghai Academy of Spaceflight Technology, Shanghai 200082, China;,   Shanghai JiaoTong LinYang Solar Photovoltaic R & D Center, Shanghai 201109, China;,   Shanghai Shenzhou New Energy Development Co., Ltd, Shanghai 201112, China
Published: December 2020

The controlling technology of micro-structure on the surface of monocrystal silicon is a hot spot issue in semiconductor and solar cell fields because the conversion efficiency of monocrystal solar cell is affected by the structure of pyramid. With the traditional alkaline solution, monocrystal Si surface is easily textured, and becomes the surface full of the pyramid. However, it is difficult to control the sizes, the shapes and the distribution of pyramids in the process. In this paper, we discuss how a new additive influences the sizes, and the shapes of pyramids during the etching process. In experiment, silicon is etched in traditional alkaline solution with addition of the new additive at a fixed temperature and time. Samples are scanned by SEM. The SEM result shows that the samples are uniformly-densely filled with pyramids with smooth edges. The size of pyramid is smaller than that etched in the traditional alkaline solution. The etched surface is covered by pyramids with 24m in size. The reflectance spectrum of the textured surface is measured. The measured reflectance decreases to 12.51%. These experimental results show that the new additive can effectively cantrol the sizes and the distribution of pyramids on the silicon surface during the texturing process, which is very meaningful to control the textured structures of single crystal silicon surface.
A kind of ferromagnetic-antiferromagnetic alternating spin chain equivalent to the mixed spin Heisenberg chain
Authors: Jiang Jian-Jun  , Yang Cui-Hong  , Liu Yong-Jun  ,   Department of Physics, Sanjiang College, Nanjing 210012, China;,   Faculty of Mathematics and Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China;,   School of Physics Science and Technology, Yangzhou University, Yangzhou 225002, China
Published: December 2020

By using the method of exact diagonalization, the properties of the spin-1/2 ferromagnetic-antiferromagnetic alternating Heisenberg chain are investigated. The spin-spin correlation, the sublattice magnetizations, the spin excitation spectrum and the magnetization curve of the model are calculated and compared with the corresponding properties of the mixed spin chain. The results show that the behaviors of the alternating Heisenberg chain are equivalent to those of the mixed spin chain when the ratio of antiferromagnetic to ferromagnetic coupling strength is very small. So, the properties of the mixed spin chain can be analyzed by using the spin-1/2 ferromagnetic-antiferromagnetic-antiferromagnetic alternating Heisenberg chain.
Stochastic resonance in coupled small-world neural networks
Authors: Yu Hai-Tao  , Wang Jiang  , Liu Chen  , Che Yan-Qiu  , Deng Bin  , Wei Xi-Le  ,   School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
Published: December 2020

Noise exists widely in biological neural systems, and plays an important role in system functions. A complex neural network, which contains several small-world subnetworks, is constructed based on a two-dimensional neural map. The phenomenon of stochastic resonance induced by Gaussian white noise is studied. It is found that only with an appropriate noise, can the frequency response of the network to input signal reach a peak value. Moreover, network structure has an important influence on the stochastic resonance of the neural system. With a fixed coupling strength, there exists an optimal local small-world topology, which can offer the best frequency response of the network.
Effects of different trends on moving cut data-approximate entropy
Authors: Jin Hong-Mei  , He Wen-Ping  , Hou Wei  , Zhang Da-Quan  ,   Department of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China;,   National Climate Center, China Meteorological Administration, Beijing 100081, China
Published: December 2020

Various trends exist in many observation data, such as periodical trend caused by seasonal variation, linear trend and polynomial trend brought about by global warming. In the present paper, the effects of different trends on moving cut data-approximate entropy are investigated. The numerical tests on model time series indicate that the detection results of moving cut data-approximate entropy are little affected by periodical trend, linear trend and nonlinear trend. The reliability of abrupt change detection of moving cut data-approximate entropy is demonstrated, which provides an experimental basis for the wide applications of the present method in real observation data.
The oscillations of a switching electrical circuit and the mechanism of non-smooth bifurcations
Authors: Wu Tian-Yi  , Zhang Zheng-Di  , Bi Qin-Sheng  ,   Facuity of Science, Jiangsu University, Zhenjiang 212013, China;,   Zhenjiang Watercraft College, Zhenjiang 212003, China
Published: December 2020

The complicated dynamical evolution of a circuit system composed of two Rayleigh-types subsystems, which are switched by a periodic switch and a threshold controller, is investigated. Through the analysis of the subsystem equilibrium points, the conditions for Fold bifurcation and Hopf bifurcation in the parameter space are given respectively. The distribution of the generalized Jacobian eigenvalues varying with auxiliary parameter at the switching boundary is presented. Then the possible bifurcation behaviors of the system at the switching boundary are obtained. The mechanisms of the different behaviors of the system are discussed. It is pointed that the trajectories of the system have two kinds of turning points, which are determined by the periodic switch and the threshold controller respectively. Meanwhile, the multiple collisions between the trajectories and the non-smooth boundary may lead the system to change from chaos to period-adding bifurcation.
A feedback neural network with weights of sinusoidal functions
Authors: Li Cheng  , Shi Dan  , Zou Yun-Ping  ,   State Key Laboratory of Advanced Electromagnetic Engineering and Technology (Huazhong University of Science and Technology), Wuhan 430074 China;,   College of Electric & Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 China
Published: December 2020

A new feedback neural network model is proposed. The network has the sinusoidal basis functions as its weights. Neuronal activation function is a linear function. The network connection form is feedback structure. An energy function is defined for the feedback neural network. And then, the network stability issue in operation is analyzed. In the Liapunov sense, the proposed feedback network stability is proved. During the operation of the network, the network states are changed ceaselessly but network weights vary according to time-dependent sinusoidal law. As the network state changes continuously, its energy will be reduced. Finally, when network comes to a stable state, its energy arrivs at a minimum value. The network is particularly suited for the adaptive approximation and the detection for periodic signals because of its sinusoidal basis function weights. It is, in practice, a new and effective way for periodic signal detection and processing. The very good detection results are obtained in the detection of power system voltage sag characteristics. Simulation examples show that the dynamic response speed of the network is very high.
Theoretical analysis on stationary Gaussian random noise in narrowband Fourier transform spectrometer
Authors: Lü Jin-Guang  , Liang Jing-Qiu  , Liang Zhong-Zhu  ,   State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;,   Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

The spectral resolution can be increased by detecting the optical signal in a narrowband spectrum for the Fourier transform spectrometer based on spatial modulated in our study. In this paper, to study the effect of the radiant source on the interference system, we regard the radiant noise as a narrowband stationary Gaussian random process. Using the linear system analysis method and the statistical theory, we deduce the input signal-to-noise ratio (SNR) and the output SNR after the optical signal and the radiant noise have passed through the interference system. Then we simulate the system and compare the obained result with a narrowband rectangle spectrum, and obtain the SNR gains along the optical path difference (OPD) in different autocorrelation degree and cross-correlation degree values. The simulation result indicates that the SNR gains at different OPDs in the correlation degree space each are a monotonic smooth surface. The SNR gain maximum moves along the radius and the contour of the correlation degree circle, and it returns to the initial position. after an OPD According to the analysis of the SNR gain, the autocorrelation degree and cross-correlation degree values can be controlled in a certain area, which can serve as a criterion for the design and the test of the radiant source.
Outgassing property of carbon nanotube cathode with intense pulsed emission
Authors: Shen Yi  , Zhang Huang  , Yang An-Min  , Xia Lian-Sheng  , Liu Xing-Guang  ,   Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China
Published: December 2020

In order to study the properties of the carbon nanotube(CNT) cathode with intense pulsed emission, the outgassing property of cathode is investigated on the 2MeV linear induction accelerator(LIA) injector. Results show that the cathode has a capability of desorbing gases from the CNT cathode under pulsed high voltage. The outgassing plays an important role in the formation of the cathode plasma. The amounts of outgassing for the several experiments are estimated to be 0.081.12PaL, the corresponding ratios between outgassing amount and electron number are roughly calculated to be in a range of 254203atoms/e- by numerical integral of pressure, showing that the cathode plasma is weakly ionized. The relationship between diode voltage, emission current density, outgassing amount, and the outgassing molecule number per electron are analyzed.
First-principles study on the Li-storage performance of silicon clusters and graphene composite structure
Authors: Wu Jiang-Bin  , Qian Yao  , Guo Xiao-Jie  , Cui Xian-Hui  , Miao Ling  , Jiang Jian-Jun  ,   Electronic of Science and Technology of Huazhong University of Science and Technology, Wuhan 430074, China
Published: December 2020

This paper focuses on the Li-storage performances and the stabilities of the hybrid structure of different lattice planes of the silicon clusters and graphene by the first-principles theory. In this paper, we calculate the binding energy, the adsorption energy, and the PDOS of the hybrid structure of the different heights and sizes of the silicon clusters and graphene. We figure out that strong Si-C bonds between the silicon cluster and graphene can form. Especially, the hybrid structure of the silicon clusters with plane (111) and graphene performs best with the highest formation energy and the outstanding stability. According to the calculation of Li-absorption energy, we conclude that the location of the silicon cluster near the graphene has higher possibility and higher absorption energy of the Li storage, owing to the charge transfers between lithium and carbon, and between lithium and silicon. Because the graphene is used, the deformation of the interface of the silicon cluster can be obviously reduced during the absorption of Li, which brings about a good future for the hybrid structure used as the battery anode materials.
Propagation characteristics of time reversal pulsed electromagnetic waves in double negative materials
Authors: Zhao De-Shuang  , Yue Wen-Jun  , Yu Min  , Zhang Sheng-Xue  ,   Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu 610054, China
Published: December 2020

With the full time-domain electromagnetic simulation technique, the time-domain propagation properties such as the temporal pulse waveform, the pulse compression and the electric field distribution inside the material are comparably investigated by transmitting the time-reversal pulsed electromagnetic wave and the pulsed electromagnetic wave through the double negative material of the Smith structure, respectively. The results show that after the time-reversal pulsed electromagnetic wave passes through the double negative material, the received electromagnetic wave exhibits remarkable spatial and temporal focusing at the location of the initial excitation. The most interesting physical phenomenon is that the peak values of the electric field inside the double negative material become smaller and tend to be uniform in the magnitude. These novel physical phenomena would be very helpful for developing new electronic devices and systems with double negative materials for the purpose of high power applications.
Optical trapping of metallic Rayleigh particles by using coherently and incoherently combined beams
Authors: Cheng Ke  , Zhong Xian-Qiong  , Xiang An-Ping  ,   College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu 610225, China
Published: December 2020

The effect of two beam combination schemes, i.e. combination of coherent and incoherent beam, on the radiation force and stability in trapping metallic Rayleigh particles is studied, where the dependences of the radiation force on beam combination scheme, off-axis distance, coherence parameter and particle radius are stressed and illustrated by numerical examples. It is shown that there exist critical values dc and c for different combination schemes. For 0ddc or 0cthe Gaussianthe Gaussian-like intensity profile takes place in the geometrical focal plane, so that the transverse gradient force can act as a restoration force to provide stable equilibrium point. Fordd0,c or00,cthe transverse gradient force can not trap metallic Rayleigh particles. For 0ddc the intensity, the radiation force, the trapping stiffness, and the longitudinal trapping range of coherently combined beam are larger than those of incoherently combined beams. Therefore, a suitable choice of combination scheme, smaller off-axis distance and coherence parameter is beneficial to trapping metallic Rayleigh particles in the use of combined beams.
The point spread function analysis in a wavefront coding system based on stationary phase method
Authors: Zhao Ting-Yu  , Liu Qin-Xiao  , Yu Fei-Hong  ,   Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, China;,   Department of Optical Engineering, Zhejiang University, Hangzhou 310027, China
Published: December 2020

Wavefront coding system with a cubic phase mask is one of important methods to extend depth of the field. This paper analyzes the characteristics of the system based on stationary phase method in space domain. By analyzing the point spread function of an arbitrary strip of the cubic phase mask, this paper points out that two stationary phase points lead to oscillations in point spread function while one stationary phase point causes a smooth curve in point spread function. Theoretical analysis illustrates that the oscillations exist in point spread function if and only if there are symmetrical components about the optical symmetrical axis. Furthermore, different areas of the point spread function correspond to different positions of symmetrical components of the mask, which is useful in the manufacture and test of the cubic phase mask. In addition, the optical symmetrical axis does not coincide with the geometrical symmetrical axis in the defocused system, causing smooth curve in defocused point spread function. As a contrast, smooth curve can not be observed in focused point spread function because of the coincidence of the symmetrical axis and the geometrical symmetrical axis.
Curved road traffic flow car-following model and stability analysis
Authors: Zhang Li-Dong  , Jia Lei  , Zhu Wen-Xing  ,   Institute of Control Science and Engineering of Shandong University, Shandong, Jinan 250061, China;,   Shandong Computer Science Center, Shandong, Jinan 250014, China
Published: December 2020

To find the characteristics of curved road traffic flow, we propose a new car-following model based on the typical full velocity difference model, and analyze the model stability condition with system state space method and control system stability criteria. With numerical simulation, the stability and feasibility of the model are proved. Under the condition of same initialization traffic flow density, with the increase of road curve, traffic flow stability decreases. Our study is greatly helpful for traffic control and management at road curve site.
Fiducial system for the diagnosis of temporal evolution of radiation fluxes with soft-X-ray spectrometer in inertial confinement fusion experiments
Authors: Song Tian-Ming  , Yi Rong-Qing  , Cui Yan-Li  , Yu Rui-Zhen  , Yang Jia-Min  , Zhu Tuo  , Hou Li-Fei  , Du Hua-Bing  ,   Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
Published: December 2020

In inertial confinement fusion experiments, a fiducial system is established in order to correlate the signals from different channels of one spectrometer and the signals from different spectrometers to obtain time-related experimental data. The constitution, the principle and the data processing method, together with the uncertainty analysis are introduced. Signals from different channels and from three spectrometers diagnosing from different directions are correlated with an uncertainty of 70 ps. The time-related historical radiation fluxes from a cylinder target, measured from three different directions, are obtained in the experiments on Shenguang Ⅲ prototype laser facility, offering the physical information about the heat wave propagation along the axis of the cylinder and the attenuation of soft X-ray radiation flux.
Investigation of 1064-nm laser damage mechanism of neutral density filter
Authors: Liu Yan-Yan  , Han Jing-Hua  , Duan Tao  , Niu Rui-Hua  , Sun Nian-Chun  , Gao Xiang  , Du Yong-Zhao  , Yang Li-Ming  , Feng Guo-Ying  ,   College of Electronics & Information Engineering, Sichuan University, Chengdu 610064, China;,   Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010, China;,   Southwest Institute of Technical Physics, Chengdu 610041, China;,   Chengdu Fine Optical Engineering Research Center, Chengdu 610041, China
Published: December 2020

The typical neutral density filter is a metal film plated on a K9 glass to achieve the effective absorption of laser. Its lower damage threshold severely restricts its application to high energy laser systems. Experimental study on damage morphology and damage mechanism of filter in a higher laser energy density is carried out. The variation characteristics of damage morphology are as follows: with the increase of laser energy density, damage spots first appear on the filter, then develop into cracks, and the cracks grow gradually longer and eventually connect into linear and block forms, resulting in a large area of film dropping off. A model of defect absorption leading to film damage on neutral density filter is established. And temperature and stress distributions on the film surface are calculated, separately. The inhomogeneous temperature rise on film surface leads to radial, hoop and axial thermal stress distributions. Theoretical analysis shows that cracks along the radial direction are caused by hoop stress. When laser energy density is larger than about 2.2 J/cm2, impurity particle radius is larger than 140 nm and the distance between impurity particles is less than 10 m. A large number of cracks can connect together to cause a large area of film to drop off.
Experimental comparison of damage performance induced by nanosecond 1 laser between K9 and fused silica optics
Authors: Liu Hong-Jie  , Wang Feng-Rui  , Luo Qing  , Zhang Zhen  , Huang Jin  , Zhou Xin-Da  , Jiang Xiao-Dong  , Wu Wei-Dong  , Zheng Wan-Guo  ,   Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
Published: December 2020

The initial damage threshold, the damage growth threshold and the damage growth laws of K9 glass and fused silica glass are tested respectively in the same experimental condition with 1 nanosecond laser. The comparison of the laser induced damage performance between the two glass materials is performed. The results show that the initial damage thresholds of the two glass materials are the same, the damage area growths both obey the exponential increase rule and their damage depth growths obey the linear increase rule. However, there is apparent difference in the rule of damage growth. For example, the damage growth threshold is lower and the damage growth coefficient is higher for K9 glass. This can be explained by the difference in the material mechanical strength between the two glass materials. The present research is very important for choosing transparent optical materials used in high power laser.
Effect of B and N doping on the negative differential resistance in molecular device
Authors: Fan Zhi-Qiang  , Xie Fang  ,   School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410004, Chian;,   School of Physics Science and Engineering Technology, Yichun University, Yichun 336000, China
Published: December 2020

By using nonequilibrium Green's functions in combination with the density-functional theory, we investigate the effects of B and N doping on the transport properties in phenalenyl molecular device. The calculated results show that negative differential resistance behavior can be observed in phenalenyl molecular device where the device current can decrease with the base voltage increasing particularly in a bias voltage region, and the peak-to-valley current ratio reaches up to 5.12. The device current can be increased before 0.8 V when the molecular center atom is replaced by B or N atom. But, the negative differential resistance behavior can be weakened and the peak-to-valley current ratio can decrease to 3.83 and 3.61, respectively. The doping effects of B and N, which are induced by the difference in extranuclear electron number between them, can make the orbitals and corresponding transmission peaks move toward high or low energy to modulate the electronic transport ability and the negative differential resistance behavior of the device.
Study of influencing factors for performance of large-scale dye-sensitized solar cells based on the semi-empirical model
Authors: Wu Bao-Shan  , Wang Lin-Lin  , Wang Yong-Mei  , Ma Ting-Li  ,   State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
Published: December 2020

Based on some physical and geometric parameters, the influence of internal resistance on the cell performance is analyzed and a semi-empirical mathematical model of the efficiency is built for some configurations of large-scale dye-sensitized solar cells. Three configurations of large-scale cells are investigated, in which the independent units are connected in series and in parallel, as well as in series-parallel. The efficiencies of the three-type large-scale cells are calculated according to their physical and geometric parameters. The applicability of the model is analyzed by comparing the calculated efficiencies with the measured ones. The influences of the physical and geometric parameters on the cell performance are investigated based on the semi-empirical mathematical model. It is found that the optimization of the performance of large-scale cells can be carried by analyzing the influences of physical and geometric parameters using the semi-empirical mathematical model.
Riemann function solutions to modified Korteweg de Vries-sine-Gordon equation
Authors: Wang Jun-Min  ,   Department of Mathematics and Information Science, Henan University of Finance and Law, Zhengzhou 450002, China
Published: December 2020

Based on some Riemnan theta function solutions to a elliptical equation, together with its Backlund transformation, infinite sequences Riemann function solutions are derived, then regarding this elliptical equation as an auxiliary equation, with the help of computer software (Mathematica), infinite sequences Riemann function solutions to the modified Korteweg de Vries sine-Gordon equation are obtained.
Interpolating reproducing kernel particle method for elastic mechanics
Authors: Li Zhong-Hua  , Qin Yi-Xiao  , Cui Xiao-Chao  ,   College of Applied Science, Taiyuan University of Science and Technology, Taiyuan 030024, China;,   College of Mechanical Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China
Published: December 2020

The displacement trial function is reconstructed by reproducing kernel particle shape function method with interpolation property on discrete points, then combining the principle of minimum potential energy of elasticity, the new interpolating reproducing kernel particle method to analyze the plane problem of elasticity is obtained. Because interpolation reproducing kernel particle shape function has a point interpolation property and no less than the high-order smoothness of kernel function, the difficulty for most of meshless methods to be used to deal with the essential boundary conditions is already overcome, and the high numerical accuracy is assured as well. Compared with the early meshless methods, this method has a high accuracy and a small scale of solving problem and it can be directly applied to boundary conditions. Numerical results for some typical examples of elasticity prove the proposed method to be valid.
Stochastic resonance of linear harmonic oscillator subjected to simple harmonic force with frequency fluctuation
Authors: Zhang Liang-Ying  , Jin Guo-Xiang  , Cao Li  ,   School of Physics and Electronic Engineering, Xiangfan University, Xiangfan 441053, China;,   Key Laboratory of Intelligent Robot of Hubei Province, Wuhan Institute of Technology, Wuhan 430073, China;,   School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
Published: December 2020

In view of the situation that the linear harmonic oscillator is subjected to the simple harmonic force with the frequency fluctuation, we work out the expression of the first-order moment for the system response. It is found that the system output response vibrates at the natural frequency, that the response amplitude shows bona-fide stochastic resonance as the simple harmonic excitation force frequency varies, and that the suppression and the resonance appears as the natural frequency varies.
A zero-watermarking algorithm of stereoscopic image based on hyperchaotic system
Authors: Zhou Wu-Jie  , Yu Mei  , Yu Si-Min  , Jiang Gang-Yi  , Ge Ding-Fei  ,   School of Information and Electronic Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, China;,   Faculty of Information Science and Engineering, Ningbo University, Ningbo 315211, China;,   College of Automation, Guangdong University of Technology, Guangzhou 510006, China
Published: December 2020

In order to protect the copyright of stereoscopic images in the condition of the image quality, a zero-watermarking stereoscopic image algorithm is presented based on hyperchaotic system. In the proposed algorithm, disparity zero-watermark is constructed according to the stability of disparity between low frequency bands of wavelet decomposition of the left and the right views and direct coefficients of discrete cosine transform; in the process of zero-watermark construction, the zero-watermark position mapping according to the features of the sensitivity of hyperchaotic discrete system initial value, ampleness of parameter key space and complexity of dynamic behavior, enhances the security of algorithm. The relationship between security and watermark capacity is also analyzed. Experimental results show that the proposed algorithm is strong robust to noise, filtering, compression, and the shearing of asymmetrical and symmetrical attacks.