bluuebunny/crossref_metadata_2025 huggingface dataset:
Spin polarized transport of two-dimensional electron gas through step-magnetic barrier structure
Authors: Tang Zhen-Kun  , Wang Ling-Ling  , Tang Li-Ming  , You Kai-Ming  , Zou Bing-Suo  ,   (1)衡阳师范学院物理与电子信息科学系，衡阳  421008; (2)湖南大学物理与微电子科学学院，长沙  410082; (3)湖南大学物理与微电子科学学院，长沙  410082；衡阳师范学院物理与电子信息科学系，衡阳  421008
Published: December 2020

By using the scattering matrix method, the properties of two-dimensional electron gas spin polarized transport through step-magnetic barrier structure at different bias voltage are investigated. The results show that (i) the degree of spin polarization is cyclically reducing if the incidence energy increases at zero bias voltage, and (ii) it is reduced slower and the maximum of spin polarization decreases when the number of steps increase in this structure, and (iii) it is enhanced significantly in a wider energy range under applied bias voltage, and more distinct spin-filtering properties are observed in the step-magnetic barriers.
Quantum corrections in fitting the switching current distributions of intrinsic Josephson junction
Authors: Cui Da-Jian  , Lin De-Hua  , Yu Hai-Feng  , Peng Zhi-Hui  , Zhu Xiao-Bo  , Zheng Dong-Ning  , Jing Xiu-Nian  , Lü Li  , Zhao Shi-Ping  ,   (1)中国科学院物理研究所，北京  100190; (2)重庆大学物理系，重庆  400044; (3)重庆大学物理系，重庆  400044； 中国科学院物理研究所，北京  100190
Published: December 2020

In the process of theoretical fitting the switching current distributions of Josephson junction,macroscopic quantum tunneling (MQT) and thermally activated process are usually considered.Analysis of the results for a Bi2Sr2CaCu2O8+δ surface intrinsic Josephson junction (SIJJ), quantum corrections are considered at the intermediate areas between MQT and thermally activated process. It is found that quantum corrections lead to a perfect fit to the experimental data, which may be useful for the future studies of MQT in SIJJs and their possible applications as a superconducting qubit.
Ferroelectric and optical properties of Pb(ZrxTi1-x)O3 bilayers
Authors: Zhao Xiao-Ying  , Liu Shi-Jian  , Chu Jun-Hao  , Dai Ning  , Hu Gu-Jin  ,   (1)上海师范大学数理信息学院,上海  200234; (2)中国科学院上海技术物理研究所,上海  200083
Published: December 2020

The uniform, dense, and crack-free PbZr0.4Ti0.6O3/PbZr0.5Ti0.5O3 bilayer with (100)-preferred crystal orientation and a single perovskite phase was fabricated on LaNiO3-coated Si substrate by using chemical solution deposition. The bilayer exhibits excellent ferroelectric properties, remnant polarization of 64μC/cm2 and coercive field of 43.6kV/cm. The prism-film coupling measurement indicates that four transverse electric modes can be excited in the system of Si/LaNiO3/PbZr0.5Ti0.5O3/PbZr0.4Ti0.6O3 and the light can be effectively confined to propagate in the guiding-layer. The refractive index and thickness for each film were obtained by solving the mode eigen-equation of the waveguide.
Highly efficient emission of Er3+ in a functionalized mesoporous silica
Authors: Lin Liang-Shu  , Xue Yan-Ling  , Jiang Qi-Cheng  , Zhang Xiao-Min  , Wu Peng  , Liu Yue-Ming  ,   (1)华东师范大学电子系，上海  200062; (2)华东师范大学上海市绿色化学重点实验室，上海  200062
Published: December 2020

Absorption spectra, emission spectra of nanoized erbium implanted mesoporous silica functionalized with and without bis(perfluoromethylsulfonyl)amine as ligand were studied. Luminescence with high intensity has been obtained. The Judd-Ofelt strength parameters Ωt(t=2,4,6)were calculated as Ω2＝1.88×10-20cm2，Ω4＝5.45×10-20cm2 and Ω6＝3.11×10-20cm2, respectively. Oscillator strength, spontaneous emission probability, branching ratio and emission lifetime of each energy levels of Er3+were given. The peak intensity of emission spectra varying with the pump power was discussed. Stimulated emission cross section (σem＝10.9×10-21cm2) was calculated and compared with that of other host materials.
Stability and convergence analysis of incompatible numerical manifold method
Authors: Wei Gao-Feng  , Li Kai-Tai  , Feng Wei  , Gao Hong-Fen  ,   (1)上海大学，上海市应用数学和力学研究所，上海  200072; (2)西安交通大学理学院，西安  710049; (3)西安交通大学理学院，西安  710049；山东轻工业学院，机械工程学院，济南  250353
Published: December 2020

The incompatible numerical manifold method (INMM) is developed on the basis of numerical manifold method (NMM). The advantages of INMM are that the calculation accuracy and computing efficiency can be greatly increased without adding generalized degrees of freedom. The expressions of element strain matrix and element stiffness matrix are given based on eliminating the internal parameters. On the basis of least potential energy theory the stability and convergence are analyzed and discussed in Hilbert space, and the basic condition ensuring uniqueness and convergence of solution is given. The theorization of INMM is perfected. To illustrate the stability and convergence of the present approach, numerical examples are provided. It is shown that this method produces highly accurate and convergent results.
Decoy state quantum key distribution with dual detectors heralded single photon source
Authors: Mi Jing-Long  , Wang Fa-Qiang  , Lin Qing-Qun  , Liang Rui-Sheng  , Liu Song-Hao  ,   华南师范大学信息光电子科技学院，光子信息技术广东省高校重点实验室，广州  510631
Published: December 2020

Decoy state has recently been proved as a useful method for substantially improving the performance of quantum key distribution (QKD). Considering the imperfect extinction ratio and the spontaneous emission of the practical Laser, vacuum states are not prepared easily. So in this paper, the optimal situation of the decoy state protocol applied to the QKD system with heralded single photon source (HSPS) is complemented and extended. The two weak decoy state protocol and the one decoy state protocol are proposed. At last, the theory of “dual detectors" is combined with the QKD system with HSPS. In the simulation, the secure distance is up to 2215 km, which is approximately 50 km more than that of the on-off detectors.
On the application of non-stationary time series prediction based on the SVM method
Authors: Wang Ge-Li  , Yang Pei-Cai  , Mao Yu-Qing  ,   (1)中国科学院大气物理研究所，北京  100029; (2)中国科学院大气物理研究所，北京  100029；南京信息工程大学大气科学学院，南京  210044
Published: December 2020

The nonstationary behaviors of complex system and their applications to the climate prediction present a significant and forward-looking study. Up to now, its importance is not yet well understood. In reality, climate is just a normal nonstationary system. However, almost all the current theories for climate prediction, including the ones in statistics and nonlinear science, are based on one assumption that the process is stationary which is contrary to the nature of the climate process. Probably, this contradictory is an important cause resulting in the climate prediction being at a low reliability level. Therefore, it is theoretically important in climate prediction to start with how to reduce the nonstationary degree of time series. In this paper, support vector machine (SVM) method based on an idea of dimension raising is presented to study the time series prediction analysis, and prediction experiments are performed using some nonstationary time series from the Lorenz model and logistic system with changing control parameter, as well as two realistic climatic time series. The prediction results suggest that the SVM method can perform well in predicting nonstationary time series, which may be due to that the SVM method can map the input space into a higher dimensional feature space through nonlinear mapping and can reduce to some extent the nonstationary degree of the system.
Probing R-parity violating interactions from top quark polarization at LHC
Authors: Lu Gong-Ru  , Li Xiang  , Li Pei-Ying  ,   (1)河南经贸职业学院电子工程系,郑州  450053; (2)河南师范大学物理与信息工程学院,新乡  453007
Published: December 2020

In minimal supersymmetric standard model, the R-parity violating interactions can induce anomalous top pair productions at the LHC through the t-channel process dRdR→tLtL by exchanging a slepton or the u-channel process dRdR→tRtR by exchanging a squark. Such top pair productions with certain chirality cause top quark polarization in the top pair events. We found that at the LHC, due to the large statistics, the statistical significance of the polarization observable and thus the probing ability for the corresponding R-parity violating couplings are much higher than at the Tevatron Upgrade.
X-ray spectra produced by interaction of Ar16+ and Ar17+ with Zr
Authors: Yang Zhi-Hu  , Song Zhang-Yong  , Cui Ying  , Zhang Hong-Qiang  , Ruan Fang-Fang  , Shao Jian-Xiong  , Du Juan  , Liu Yu-Wen  , Zhu Ke-Xin  , Zhang Xiao-An  , Shao Cao-Jie  , Lu Rong-Chun  , Yu De-Yang  , Chen Xi-Meng  , Cai Xiao-Hong  ,   (1)兰州大学现代物理系，兰州  730000; (2)咸阳师范学院物理系，咸阳  712000; (3)中国科学院近代物理所，兰州  730000
Published: December 2020

The 10—20qkeV Ar16+ and Ar17+ ions produced by SECRAL enter on metallic surface of Zr. In this interaction，the multi-electron excitation possibly occurred in the neutralization of the highly charged Ar16+ ions，which produced vacancy in the K shell. Electron of the high n state de-excited to K vacancy gives off X-ray. The experimental results show that X-ray intensities for the Ar hollow atom decrease with increase of incidence energy，and Lβ X-ray intensities of target atom Zr increase with increasing incidence energy. Kα X-ray yield per ion for Ar17+ was five orders of magnitude greater than that for Ar16+.
A composite Si-PIN 14MeV neutron detector
Authors: Zhang Xian-Peng  , Ouyang Xiao-Ping  , Zhang Zhong-Bing  , Tian Geng  , Chen Yan-Li  , Li Da-Hai  , Zhang Xiao-Dong  ,   (1)西北核技术研究所，西安  710024; (2)西北核技术研究所，西安  710024；西安交通大学核科学与技术学院，西安  710049
Published: December 2020

This paper presents the principle of a new composite (C2H4)n-PIN sandwiched fusion neutron detector, which uses 2mm (C2H4)n as sensitivity enhancement medium, and add circuit to merge the output signals. The main merits of the detector are: (1) greatly improved neutron sensitivity and better statistics; (2) improved n/γ discrimination; (3) implementing the signal summation without obviously affecting the time response. Characteristics of the detector, including the sensitivity to 14MeV neutron and 1.25MeV γ ray, n/γ discrimination, time response, and statistics are studied theoretically and experimentally.
Effect of partial coherence laser arrays on far-field output properties
Authors: Xiao Rui  , Hou Jing  , Jiang Zong-Fu  ,   国防科技大学光电科学与工程学院，长沙  410073
Published: December 2020

Quantitative details about coherence are important for determining the performance of laser arrays. In this paper，we deduce the analytical equation of the far-field intensity distribution in partially coherent combining of fiber laser arrays and investigate its effects on the far-field patterns, the FWHM of the central far-field lobe, strehl ratio and power in the bucket. The master oscillator-power amplifier scheme was used to realize phase control of three ytterbium fiber amplifiers, and the experimental results are presented.
Entropy squeezing of the optical field in k-photon Jaynes-Cummings model
Authors: Kang Dong-Peng  , Ren Min  , Ma Ai-Qun  , Qian Yan  , Liu Zheng-Jun  , Liu Shu-Tian  ,   (1)广州大学工程抗震中心，广州  510405; (2)哈尔滨工业大学物理系，哈尔滨  150001; (3)哈尔滨工业大学物理系，哈尔滨  150001；广州大学城建学院，广州  510900；黑龙江大学物理科学与技术学院，哈尔滨  150080; (4)黑龙江大学物理科学与技术学院，哈尔滨  150080
Published: December 2020

We investigated the field entropy squeezing of k-photon Jaynes-Cummings model，discuss the influence of the photon number k and the initial state of the atom on the entropy squeezing. The results show that with the photon numberk increasing，the position entropy squeezing will be enhanced and the momentum entropy squeezing reduced. When k≥3，the position entropy is always squeezed. The initial state of the atom also shows some influence on the entropy squeezing.
Highly precise active-synchronization between two independent femotosecond Ti: sapphire oscillators
Authors: Zhao Huan  , Zhao Yan-Ying  , Tian Jin-Rong  , Wang Peng  , Zhu Jiang-Feng  , Ling Wei-Jun  , Wei Zhi-Yi  ,   中国科学院物理研究所 北京凝聚态物理国家实验室，北京  100080
Published: December 2020

We demonstrate the highly precise active-synchronization between two independent Ti: sapphire femtosecond oscillators. A combination of three phase locked loops, is used to control the synchronization between two laser pulses，which gives a RMS timing jitter less than 30fs. With the technique of cavity length monitoring and autocontrol by a computer，this highly precise synchronization can be retained for more than 40 minutes.
The performance of phase-only liquid crystal spatial light modulator used for generating Zernike terms
Authors: Cai Dong-Mei  , Ling Ning  , Jiang Wen-Han  ,   (1)中国科学院成都光电技术研究所，自适应光学国家重点实验室，成都  610209; (2)中国科学院成都光电技术研究所，自适应光学国家重点实验室，成都  610209；中国科学院研究生院 北京  100039
Published: December 2020

The liquid crystal spatial light modulators (LC-SLM) are recently emerging as wavefront aberration correctors for use in low cost adaptive optics system (AO). As a novel aberration corrector，the wavefront generation performance of a phase-only LC-SLM is a governing factor that determines its ability for wave-front correction in an AO system. In this article，the performance of wave-front generation of LC-SLM is demonstrated by the production and quantification of the first 36 Zernike terms with different values. The factors，such as the fill factor，fringe field effect，pixel structure，the phase wrapping method and different phase strokes to impact wave-front generation are analyzed.
Molecular dynamics simulation of shock-induced collapse in single crystal copper with nano-void inclusion
Authors: Yang Qi-Li  , Zhang Guang-Cai  , Xu Ai-Guo  , Zhao Yan-Hong  , Li Ying-Jun  ,   (1)北京应用物理与计算数学研究所计算物理实验室，北京  100088; (2)中国矿业大学(北京)，北京  100083
Published: December 2020

The evolution of preexisting nano-voids of different size in single crystal copper is investigated by means of molecular dynamics (MD) simulations. The results show that void collapse depends upon the size of the void. Numerous dislocation loops emerge for large void and phase transformation takes place in the sample. When the shock wave passes the void from left to right，dislocation loop emerges in the right of the void first for small void. However，loops emerge in the right and the left at the same time when the size of the void increases to a critical size，which is decided by the distribution of the stress near the void. Once dislocation loop emerges and grows，the frontal dislocation loop in the right of void grows faster than that in the left for the same void. When the size of the void increases，the velocity of frontal dislocation loops is essentially unvaried，and the angle between the direction leading from the centre of the void to the initial position of collapse and the direction of impact increases.
Modelling the universal dielectric response in heterogeneous materials using 3-D RC networks
Authors: Xiao Zhe  , Huang Ming  , Wu Yue-Feng  , Peng Jin-Hui  ,   (1)昆明理工大学材料与冶金工程学院，昆明  650093; (2)云南大学信息学院，昆明  650091; (3)云南大学信息学院，昆明  650091；昆明理工大学材料与冶金工程学院，昆明  650093
Published: December 2020

In this paper，a three-dimensional RC networks model has been developed，and the RC networks has been coded，modeled and simulated based on Matlab and C programming language. The complex permittivity of this model has been calculated. The dielectric properties of RC networks containing 54，144，300，540 and 882 components have been computed. It was found that these properties exhibit the anomalous power law dependence on frequency known as the ‘universal dielectric response’ (UDR). The UDR is stable for RC networks containing 300 or more components. When the capacitor is 100nF，10nF，1nF and 100pF，respectively，the simulation results of normalized complex permittivity versus angular frequency for RC networks containing 540 components have been obtained. The relation between normalized complex permittivity and angular frequency for the RC networks containing 540 components in the ratios 4% R-96% C，7% R-93% C，10% R-90% C，16% R-84% C，33% R-67% C have been simulated. The results show that the UDR in heterogeneous materials can be modelled and simulated by 3-D RC networks，and has non-Debye nature.
The characteristics of the spectrum emitted from dielectric barrier-discharge plasmas
Authors: Li Han-Ming  , Li Gang  , Li Ying-Jun  , Li Yu-Tong  , Zhang Yi  , Cheng Tao  , Nie Chao-Qun  , Zhang Jie  ,   (1)中国科学院工程热物理研究所，北京  100080; (2)中国科学院物理研究所光物理实验室，北京  100080; (3)中国科学院物理研究所光物理实验室，北京  100080；上海交通大学物理系，上海  200240; (4)中国矿业大学(北京)理学院，北京  100083；中国科学院物理研究所光物理实验室，北京  100080
Published: December 2020

In order to optimize the parameters of dielectric barrier-discharge plasmas, the emission spectrum of second transition line of oxygen and nitrogen under normal temperature and pressure was measured with a grating spectrometer. The results show that the intensity of the emission spectrum of the plasma increases with the voltage, and the best frequency range to generate the plasma spectrum is 39—41kHz. Meanwhile, the introduction of helium gas increases the intensity to a high extent. In combination with the theoretical analysis, the feasibility of spectral method in the study of dielectric barrier discharge plasma is verified.
Rules of the population distribution of China and its evolution mechanism
Authors: Shi Hua-Ping  , Ke Jian-Hong  , Sun Ce  , Lin Zhen-Quan  ,   温州大学物理与电子信息学院，温州 325035
Published: December 2020

The characteristics of the population distribution of China is analyzed based on the method of statistical physics. The results show that in the last 20 years, the total population of China increases roughly exponentially with time and the growth rate is found to be slowing down. The population distribution in provinces, cities or counties follows approximately the same rule: the population distribution changes slowly for small k, while it changes rapidly for large k and the distribution obeys the Zipf's law. This shows that the population distribution of China has self-similarity. A solvable model of migration-driven aggregate growth based on scale-free network is also proposed to simulate the population size distribution of China. It is found that the theoretical results are in good agreement with the realistic data.
Effect of the time period modulation of color noise correlation intensity on the stochastic resonance of the single-mode laser
Authors: Chen De-Yi  , Wang Zhong-Long  ,   三峡大学理学院物理系，宜昌  443002
Published: December 2020

Stochastic resonance is studied in single-mode laser driven by colored noise with time period modulation of the noise correlation intensity. By means of the linear approximation method, we calculate the power spectrum and signal-to-noise ratio of the laser intensity. Effects of the noise intensity D and Q, the time period modulation frequency Ωλ, the noise self-correlation-time τ1 and τ2, and the noise correlation intensity λ on the signal-to-noise ratio R are discussed. The results reveal that the evolution of the signal-to-noise ratio with the noise intensity shows the single-peak resonance, the evolution of the signal-to-noise ratio with the time period modulation frequency shows periodic resonance and the evolution of the signal-to-noise ratio with the noise self-correlation-time shows monotonie increase.
A full electromagnetic analysis of a filter substrate lens for spatiotemporal terahertz pulse shaping
Authors: Zhu Yan-Wu  , Shi Shun-Xiang  , Liu Ji-Fang  , Sun Yan-Ling  ,   西安电子科技大学技术物理学院,西安  710071
Published: December 2020

A novel filter substrate lens for THz pulse is presented, which could efficiently couple the THz radiation in a desired frequency range into free space. The band-pass and band-stop filter lens is designed and studied by difference time method. The results show that the design is well supported by the theoretical analyses.
Numerical calculation of the electron-phonon coupling relaxation time in pulse laser ablation
Authors: Hu De-Zhi  ,   华北科技学院基础部,三河  065201
Published: December 2020

The key to improving the quality of thin film prepared by pulse laser deposition, is to properly control the electron-phonon coupling relaxation time which determines the pulse duration and the laser fluence. Taking the aluminum targets as an example, we obtain the evolution temperature of electron subsystem and ionsubsystem by solving the standard two temperature equation using the finite-difference time-domain (FDTD) method. Then, we obtain the electron-phonon coupling relaxation time, which can distinguish between the thermal ablation and the non-equilibrium ablation to ensure that we can control the process of pulse laser ablation well. In addition, we find out how does the electron-phonon coupling relaxation time change with the pulse duration and the laser fluence.
Effects of various inductances on the dynamic models of the Z-pinch implosion of nested wire arrays
Authors: Ding Ning  , Zhang Yang  , Liu Quan  , Xiao De-Long  , Shu Xiao-Jian  , Ning Cheng  ,   北京应用物理与计算数学研究所，北京  100088
Published: December 2020

Z-pinch experiments have demonstrated that the soft X-ray power increases 40% with a nested-wire array compared with that with a single-layered wire array. However, the development of the technique of obtaining higher X-ray power using nested wire array configurations has been largely empirical. This has, in part, been due to the absence of adequate theoretical models to describe the mechanism of interaction of the two arrays. As is well known, 2D MHD modeling of nested wire array implosions is difficult, and is very inconvenient to optimize the design of nested-wire arrays. In this paper, the Z-pinch implosion dynamics of nested wire array has been described by its equivalent electric circuit and by solving the corresponding circuit equation. The currents flowing through the outer and inner arrays in the initial stage of implosion depend on the array dimensions, especially on the array inductances. The analysis indicates that the arrays inductance variation can result in four dynamic models of the Z-pinch implosion of nested wire arrays, which is the same as that predicted by previous works. Fast and inexpensive 0D modeling can predict the implosion time and the rate of thermalization of the kinetic energy of the nested-wire array at Qingguang-1 facility, and estimate the implosion model that the inner array wires remain discrete until the outer array material has passed through their gaps. The full current is then transferred rapidly to what was initially the inner, imploding it rapidly onto the outer array material on the axis. Some suggestions are put forward which may be helpful in the nested-wire array design for Z-pinch experiments.
Semi-analytical dual edge element method and its application to waveguide discontinuities
Authors: Chen Jie-Fu  , Zhu Bao  , Zhong Wan-Xie  ,   大连理工大学工业装备结构分析国家重点实验室，大连  116023
Published: December 2020

A semi-analytical dual edge element is proposed to solve the waveguide discontinuities. The governing equations for electromagnetic waveguide are converted to the Hamiltonian system, and the corresponding variational principle based on the dual variables is given. For waveguide sections which are homogeneous along the longitudinal direction, the dual edge element is employed to discretize the cross section, and a precise integration method based on the Riccati equations is used for the longitudinal integration to generate the export stiffness matrices. The whole waveguide discontinuity problems can be solved by combining the export stiffness matrices of homogeneous waveguide sections with the system matrices by conventional three-dimentional finite element method for inhomogneous waveguide sections. Numerical examples demonstrate the high accuracy and efficiency of this method for solving waveguide discontinuity problems.
A cellular automaton model for dendrite solidification of pure substance
Authors: Shan Bo-Wei  , Lin Xin  , Wei Lei  , Huang Wei-Dong  ,   西北工业大学凝固技术国家重点实验室，西安  710072
Published: December 2020

A cellular automaton (CA) model was developed to describe microstructural evolution of pure substance. A self-consistent interface energy conservation was used to determine the growth velocity of solid-liquid interface instead of the KGT model as is commonly used in previous CA models. The mesh and time dependency of the morphological evolution was also investigated, and the stability of the model was validated. The free dentritic growth of pure succinonitrile in the undercooled melt was simulated by the present model. The results were compared with Glicksman's isothermal dendtitic growth experiment and LMK marginal stability theory. The model reproduced qualitatively most of the dendritic features observed experimentally. The results were in good agreement with theoretical and experimental results.
Vacancy induced spin state transition in La0.7Sr0.3-x□xCoO3 (0≤x≤0.2) cobaltites
Authors: Xie Qi-Yun  , Wu Xiao-Shan  ,   南京大学固体微结构国家实验室，南京大学物理系，南京  210093
Published: December 2020

Effects of vacancy doping in polycrystalline La0.7Sr0.3-xxCoO3 (0≤x≤0.2) cobaltites on their crystal structure, magnetic and transport properties have been systematically investigated. With increasing Sr deficiency, the antiferromagnetic superexchange is promoted at the expense of double exchange between ferromagnetic clusters, with cluster-glass state being prevailing, which is due to the gradual decrease of A site ionic radius as well as more intrinsic disorder. As x is increased beyond 0.1, it is found that the Co—O bond length shrinks remarkably. This tends to enlarge the crystal-field splitting energy and most Co3+ ions are inclined to prefer low spin states. The ground state shows superparamagnetic-like features, thus giving rise to metal-insulator transition.
Ultraviolet resonant Raman scattering in InGaN films
Authors: Wang Rui-Min  , Chen Guang-De  ,   西安交通大学理学院大学物理部，西安  710049
Published: December 2020

Ultraviolet Raman scattering spectra of InxGa1-xN films with different In compositions were investigated using 325nm laser line. For photon energy above the energy gap, strong enhanced 2A1(LO)phonon scattering lines were observed. Four 2LO peaks shift from twice the energy of the first-order LO peak, to the high energy end and the shifts increase with In contents in the samples. It is attributed to the multiple resonance resulting from intraband-Frhlich interaction. The composition dependence of LO phonon mode frequency and line shape was analysed. The phase separation was observed in Raman spectra and compared with the data of X-ray diffraction. Furthermore, the E2 phonon combination mode of InxGa1-xN was observed at about 1310cm-1.
Revealing the transport mechanisms of silicon oxidation by H218O/H216O isotopic labeling
Authors: Gong Jia  , Jiang Yi-Ming  , Zhong Cheng  , Deng Bo  , Liu Ping  , Li Jin  ,   复旦大学材料科学系，上海  200433
Published: December 2020

A new method was proposed to investigate the transport mechanism of silicon oxidation at 1100 ℃ using H216O/H218O isotopic labeling. The formation and structure of silicon oxide film was analysed. The distribution of 16O and 18O in the oxide film was analysed by means of secondary ion mass spectroscopy (SIMS). The results demonstrate that the oxide film is non-crystalline during the oxidation of silicon in the water vapor and the transport mechanism is substitutional diffusion mechanism.
Lag synchronization in uncertain autocatalytic reaction-diffusion chaotic systems
Authors: Lü Ling  , Li Yan  ,   辽宁师范大学物理与电子技术学院,大连 116029
Published: December 2020

A lag synchronization controller is designed to realize synchronization between spatiotemporal chaos systems. The structure of the lag synchronization controller and the error equations of state variables are determined based on Lyapunov stability theory. Autocatalytic reaction-diffusion chaotic system is taken as an example to verify the effectiveness of the controller. The parameter identifier is further designed to provide effective identification of the parameters in the uncertain autocatalytic reaction-diffusion chaotic system. The method is proved to have better performance in anti-jamming by studying the synchronizing effect under bounded noise.
Effect of F?rster-type bimolecular annihilation on fluorescence decay of porphyrin side-chain polymer
Authors: Li Ai-Zhen  , Chen Zhi-Feng  , Wang Hui  , Zhang Yan-Wei  , Zhang Wei  , Yu Han-Cheng  , Huang Jin-Wang  , Ji Liang-Nian  ,   (1)中山大学光电材料与技术国家重点实验室，广州  510275; (2)中山大学光电材料与技术国家重点实验室，广州  510275;中山大学东校区实验中心，广州  510006; (3)中山大学化学与化学工程学院 / 中山大学生物无机与合成化学教育部重点实验室，广州  510275
Published: December 2020

Transient fluorescence dynamics of a new kind of porphyrin side-chain polymer film ［poly［porphyrin acrylate-styrene］ (P［(por)A-S］) at high excitation density has been measured by using time-resolved fluorescence spectroscopy. The fluorescence decay becomes more rapid with the increase of the interchain polymer concentration. The origin of the concentration quenching has been analysed according to the Frster-type bimolecular annihilation theory. The theoretical analyses are in good agreement with the experimental results. Rosults show that, in the case of high excitation density, the Frster-type bimolecular annihilation is the main reason of the fast initial luminescence decay and the low luminescence efficiency of the porphyrin side-chain polymers.
Recent progress in cubic boron nitride film synthesis
Authors: Yang Hang-Sheng  , Nie An-Min  , Zhang Jian-Ying  ,   浙江大学材料科学与工程学系，杭州  310027
Published: December 2020

Cubic boron nitride (cBN) thin films, as artificially prepared materials, have excellent mechanical, thermal, electronic and optical properties, thus have potentially significant technological applications in cutting tools, high-temperature electronic devices, and protective coatings for optical elements. Cubic BN films have attracted worldwide attention since the early 1980s; however, a numbers of difficulties hindered their applications. In this paper, recent important achievements in cBN film preparation are reviewed, and perspectives for future study of cubic boron nitride film are presented.
The statistical prosperities of single-mode laser system driven by colored cross-correlation noises
Authors: Wang Bing  , Shao Ji-Hong  , Wu Xiu-Qing  ,   安徽理工大学理学院，淮南  232001
Published: December 2020

Using a single-mode laser cubic model driven by additive colored noise and multiplicative colored noise，through theory of Novikov，Fox approximation and the approximation of Stratonovich，an expression of intensity correlation function C was reached at. The effects of the correlation time τ，the net gain a0 and the cross-correlation intensity λ on the intensity correlation function C was investigated. The result of numerical simulation shows that the intensity correlation function C increases with the correlation time τ for the net gain above the threshold （a0>0），but decreases as correlation time increases for the net gain below the threshold （a0C decreases as cross-correlation λ intensity increases no matter the net gain is above or below the threshold. The curve of C versus a0 has a single peak.
Adaptive synchronization between different fractional hyperchaotic systems with uncertain parameters
Authors: Hu Jian-Bing  , Han Yan  , Zhao Ling-Dong  ,   中北大学电子测试技术国家重点实验室，仪器科学与动态测试教育部重点实验室，太原  030051
Published: December 2020

This paper addresses parameter identification and the adaptive synchronization between fractional CYQY hyperchaotic system and fractional Lorenz hyperchaotic system with uncertain parameters. Based on fractional stability theory，an adaptive controller and the paramter updating rule are designed. Numerical simulation shows the effectiveness of the adaptive controller.
Polarization switching performance of VCSEL subjected to optical pulse injection
Authors: Yang Bing-Xing  , Xia Guang-Qiong  , Lin Xiao-Dong  , Wu Zheng-Mao  ,   西南大学物理学院，重庆  400715
Published: December 2020

Based on the rate equations describing the dynamic characteristics of the master and slave vertical cavity surface emitting laser （M-VCSEL，S-VCSEL）, under the modulation of pulsed bias current，the polarization characteristics of M-VCSEL output and the polarization switching performance of S-VCSEL subjected to optical pulse output from the M-VCSEL have been investigated. The results show that periodical pulses can be obtained by adding a periodical pulsed current on the M-VCSEL. Under injection of the optical pulsed from M-VCSEL, the output power of S-VCSEL will switch periodically between two orthogonal polarizations，and the period is equal to the period of the modulated current in M-VCSEL. Through changing the modulated amplitude of current in M-VCSEL，the orthogonal polarization suppression ratio （OPSR） can be controlled easily.
Some origins of the low excitability of a discrete excitable medium
Authors: Dai Yu  , Tang Guo-Ning  ,   广西师范大学物理与电子工程学院，桂林  541004
Published: December 2020

The simple model of discrete excitable medium is applied. In order to make spiral wave meander，we introduce some death cells and fatigue cells into a homogeneous medium，respectively，or periodically change the excitation threshold of cells. By monitoring the fraction of excitation cells，we find that there is a remarkable common feature for spiral wave meandering induced by different factors，i.e.，the fraction of excitation cells under spiral wave meandering is smaller than that under stable spiral wave，which indicates that the low excitability of a medium is related to the number of death cells and fatigue cells in the medium，and the periodical change of the excitation threshold of cells，respectively. The numerical results show that the decrease of the excitability of media always accompanies the decrease of the frequency of spiral wave. We hope the present work can provide help for medical workers on the prevention and treatment of heart disease.
Influences of signal light and bus-stop position on T-road junction traffic
Authors: Mei Chao-Qun  , Huang Hai-Jun  , Tang Tie-Qiao  , Wang Hui-Wen  ,   (1)北京航空航天大学交通科学与工程学院，北京  100191; (2)北京航空航天大学经济管理学院，北京  100191; (3)北京航空航天大学经济管理学院，北京  100191；首都经济贸易大学统计学院 北京  100070
Published: December 2020

In this paper，we apply a nonlinear map model to investigate the influences of signal light and position of bus-stop on the traffic at a T junction. The dependence of point-based average flow of routes on bus-stop position，signal light cycle and split as well as vehicle swerve are numerically analyzed. Simulation results show that the interaction between bus-stop and signal light generates traffic clustering easily，and there exist relationships between signal light cycle，split，bus-stop position and the route flows.
Non-equilibrium molecular dynamics simulation for mechanism and drag reduction of underwater supercavitation in open system
Authors: Gong Bo-Zhi  , Zhang Bing-Jian  ,   浙江大学化学系，杭州  310027
Published: December 2020

Non-equilibrium molecular dynamics was introduced for studying supercavitation mechanism and its drag reduction effect. Flow field details like local density distribution，local cavity number distribution，friction coefficient and gas volume percentage were calculated. The results showed that cavity number criterion is applicable in predicting supercavitation. Low cavity number area and actual cavity area are spatially separated. Velocity was the critical factor on cavity formation. Cavitator shape can affect gas volume percentage in cavity. Supercavitation can bring about 50%—90% skin friction reduction，comparing with cloud cavitation. The results agree with previous numerical simulation，showing the model is suitable for studying supercavitation mechanism in molecular scale and provides a valuable tool for investigating flow details.
Theoretical study on the structure，spectra and thermodynamic property of 2-（toluene-4-sulfonylamino）-benzoic
Authors: Xu Bu-Yi  , Chen Jun-Rong  , Cai Jing  , Li Quan  , Zhao Ke-Qing  ,   四川师范大学化学与材料科学学院，成都  610066
Published: December 2020

The structure optimization and frequency calculation have been carried out at B3LYP/6-31++G** theoretical level，and IR spectrum，Raman spectrum and thermodynamic property at different temperatures have been obtained. The results indicate that the carbon and the oxygen in the —COOH group，and the nitron in —（OS）2—NH group come into formation of different large π bonds with the benzene rings，and there is a dihedral angle of 63.2° because of place blocking and conjugate effect. The first vertical excited state electronic transition energy was calculated by time-dependent density functional theory，and the maximal absorption wavelength was obtained at 312.7?nm，belonging to near UV，which is in good agreement with experimental value of 307?nm in dichloromethane solvent.
Asymmetry of molecular reactive collision of the DTO molecules
Authors: Ruan Wen  , Luo Wen-Lang  , Zhang Li  , Zhu Zheng-He  , Fu Yi-Bei  ,   (1)四川大学原子与分子物理研究所，成都  610065; (2)四川大学原子与分子物理研究所，成都  610065；井冈山大学数理学院，吉安  343009
Published: December 2020

Based on the potential energy function which considers the nuclear motion and isotopic effect of DTO (X1A1), the atomic and molecular reactive collision for O+DT has been studied by Monte-Carlo quasi-classical trajectory approach. It is shown that the reaction O+DT→DTO with a long-lived complex compound has no threshold energy at low collision energy, which agrees with the potential surface. When the collision energy is higher than 209.2 kJ·mol-1, the interchange reactions will start and then increase until DTO molecules are decomposed completely into D, T, O with the collision energy increasing. The interchange reactions O+DT(0, 0)→OD+T and O+DT (0, 0)→OT+D have corresponding threshold energies. The trajectories and collision section of interchange reactions show asymmetrical distribution which corresponds to the potential surface.
Spectroscopic parameters and potential energy function of the ground state of ArH
Authors: Zhu Ji-Liang  , Ren Ting-Qi  , Wang Qing-Mei  ,   曲阜师范大学物理工程学院,曲阜  273165
Published: December 2020

The structure and dissociation energy of the ground state of ArH+ are calculated using QCISD（T）/ Aug-CC-pVTZ method. Based on the theory of atomic and molecular statics，the reasonable dissociation limit for the ground state （1Σ+） of ArH+ is derived. The potential energy curve and relevant optical constants of this state are obtained by least square fitting to the Murrell-Sorbie function. All calculation results are in good agreement with the experimental data.
Increasing line-density of high-order harmonic generation spectra with bichromatic fields
Authors: Liu Shuo  , Chen Gao  , Chen Ji-Gen  , Zhu Qi-Ren  ,   (1)长春理工大学理学院物理系，长春  130022; (2)吉林大学原子与分子物理研究所，长春  130012; (3)台州学院物理系，椒江  318000
Published: December 2020

By numerically solving time-dependent Schrdinger equation, we obtain high-order harmonic generation （HHG） spectra from the one-dimensional H atom model submitted to linear polarization bichromatic field. It is found that, appropriate bichromatic field could be a source of attosecond pulse generation since it produces a ligher line-density in harmonic generation spectra （HGS）. Based on it, we analyze the mechanism of generating denser HHG spectral lines in detail, and give density-selection numerical experiential formulas for different pulses duration, to achieve further control of the line density of HGS.
Size dependent luminescence properties of Er3+ doped nano-crystalline Y2O3
Authors: Xiao Si-Guo  , Yang Xiao-Liang  , Ding Jian-Wen  , Yan Xiao-Hong  ,   (1)南京航空航天大学理学院,南京 210016; (2)湘潭大学材料与光电物理学院，纳米物理与稀土发光研究所,湘潭 411105;低维材料及其应用教育部重点实验室，湘潭 411105
Published: December 2020

Er3+ doped Y2O3 nano-crystals with different size are prepared using combustion method. Size effect on luminescence properties of Er3+ doped Y2O3 nano crystals are investigated. No shift of the absorption peak in the photo-acoustic spectra is observed with the decrease of the Y2O3particle size, indicating that the size induced energy shifts of the rare-earth levels are negligible. However, the emission spectra under 488nm excitation indicate that the ratio of the intensity of 4S3/2→4I15/2 transition to that of 2H11/2→4I15/2 decreases with the decrease of the particle size. It is believed that the rate of hypersensitive transition of 2H11/2→4I15/2 increases with the decrease of the particle size more quickly than that of transition of 4S3/2→4I15/2. The time dependence of the 554nm luminescence decay excited by 518nm reveals that the rate of up-converted energy transfer occurring between two Er3+ ions in 4S3/2 state increases with the decrease of the particle size.
Optical experimental verification of two-step generalized phase-shifting interferometry
Authors: Meng Xiang-Feng  , Cai Lü-Zhong  , Wang Yu-Rong  , Peng Xiang  ,   (1)山东大学光学系,济南  250100; (2)深圳大学光电工程学院,深圳  518060
Published: December 2020

A wavefront reconstruction technique by two-step generalized phase-shifting interferometry （GPSI） is proposed and verified by optical experiments. According to the statistical characters of the diffractive field, a blind extraction algorithm is developed, by which the unknown phase shift value in interferometry can be successfully extracted. The proposed method can retrieve the real amplitude of object wave field by using two interferograms, the recorded object and reference wave intensities, and an extracted phase shift, without the assistance of additional Fourier spectrum analysis or digital filtering. In optical experiments, the feasibility of this method for both the indirect object （digital images cast on a spatial light modulator, SLM） and the direct three-dimensional diffused object inputs has been discussed and investigated in detail, and the experimental results have convincingly verified the usefulness and effectiveness of this scheme in practice.
Enhancement of three-mode Gaussian state light field nonlocality
Authors: Zhou Ben-Yuan  , Huang Hui  , Li Gao-Xiang  ,   (1)华中师范大学物理科学与技术学院，武汉  430079; (2)华中师范大学物理科学与技术学院，武汉  430079；空军雷达学院物理教研室，武汉  430019
Published: December 2020

Here we propose a scheme for enhancing the nonlocality of three-mode Gaussian state light fields. It is found that three-mode Gaussian State can become non-Gaussian by the non-Gaussian operation of an IPS process, It is vertified that nonlocality of Gaussian state can be enhanced by Bell inquality.
Experimental investigation of LD-pumped Cr,Tm,Ho∶YAG single longitudinal mode microchip laser
Authors: Lin Zhi-Feng  , Zhang Yun-Shan  , Gao Chun-Qing  , Gao Ming-Wei  ,   北京理工大学信息科学技术学院光电工程系，北京  100081
Published: December 2020

Study of LD pumped single longitudinal mode Cr,Tm,Ho∶YAG microchip laser pumped by a 785?nm laser diode（LD） is reported. The pump threshold power of the Cr,Tm,Ho∶YAG microchip laser was 1060?mW and the maximum single longitudinal mode output power was 31?mW. The output power against the laser crystal temperature demonstrated the temperature sensitivity of Cr,Tm,Ho∶YAG crystal. The frequency tuning property of the Cr,Tm,Ho∶YAG microchip laser was also measured by changing the temperature of the crystal, and a tuning coefficient of 14?GHz/℃ was obtained.
Time-varying thermal effect of laser crystal in pulsed diode laser side-pumped Nd∶YAG laser
Authors: Song Xiao-Lu  , Guo Zhen  , Li Bing-Bin  , Wang Shi-Yu  , Cai De-Fang  , Wen Jian-Guo  ,   西安电子科技大学技术物理学院,西安  710071
Published: December 2020

In pulsed diode laser side-pumped solid-state laser, time-varying distribution of temperature in laser crystal is numerically calculated. Three-direction pumped beam intensity distribution in laser crystal is analyzed. Based on the solution, the temperature distribution and its influence in single-pulse process of pulsed diode laser array side-pumped Nd∶YAG laser is obtained by finite element method. The results show that the process of temperature rise is influenced by pump condition and cooling method, but the main influencing factor are the pump conditions such as pumping power and beam waist. Cooling process is influenced by crystal thermo-physical parameters, radius and cooling condition. After the transient temperature distribution has reached dynamic equilibrium, because of radius temperature gradient periodically changing with time, the optical path difference between center and edge beam is also periodically changing with time.
Experimental study of the nonlinear hot image effect of broadband pulsed laser beams
Authors: Wang You-Wen  , Deng Jian-Qin  , Wen Shuang-Chun  , Tang Zhi-Xiang  , Fu Xi-Quan  , Fan Dian-Yuan  ,   (1)湖南大学计算机与通信学院微纳光电器件及应用教育部重点实验室,长沙  410082; (2)湖南大学计算机与通信学院微纳光电器件及应用教育部重点实验室,长沙  410082；衡阳师范学院物理与电子信息科学系,衡阳  421008
Published: December 2020

The experimental investigation of the nonlinear hot image effect in brand-band pulsed laser beams is reported, placing emphasis on the observation of the formation of hot images and the influence of incident average power of pulse, pulse width, and thickness of the nonlinear medium on the location and intensity of hot images. It is shown that, hot images can be formed from obscurations in the broadband laser beam through a nonlinear Kerr medium slab, as in the case of the monochromatic continious light beam, and are located in the plane symmetrical to the obscuration with respect to the nonlinear slab. In addition, with the incident average power of pulse increasing, the intensity of hot image increases and ultimately reaches saturation, while with the pulse width increasing, the intensity of hot image decreases for a pulse of given energy. On the contrary, it increases for a pulse of given peak power.
Study of scattering angular distribution of proton using Monte-Carlo method
Authors: Ju Zhi-Ping  , Cao Wu-Fei  , Liu Xiao-Wei  ,   中山大学物理科学与工程技术学院，广州  510275
Published: December 2020

The single-scattering-foil method is the basic of passive proton beam spreading system. In this paper, the angular distribution and energy distribution of proton beam on passing through a single scattering foil are calculated using Monte-Carlo multi-particle transport code Fluka2006.3b.2., including the effect of proton energy, scattering material and target thickness on scattering angle. The result shows that thin-high-atomic-number material can be used as the scattering material.
Investigation of the operation characteristics of terahertz-wave parametric oscillator based on LiTaO3
Authors: Sun Bo  , Liu Jin-Song  , Ling Fu-Ri  , Wang Ke-Jia  , Zhu Da-Qing  , Yao Jian-Quan  ,   (1)华中科技大学光电子科学与工程学院，武汉光电国家实验室，武汉  430074; (2)华中科技大学光电子科学与工程学院，武汉光电国家实验室，武汉  430074；天津大学精仪学院激光与光电子研究所，天津  300072
Published: December 2020

Based on the basic principle of the stimulated polariton scattering process, the operation characteristics of terahertz-wave parametric oscillators （TPOs） using the LiTaO3 （LT） crystal, including the ability of frequency-tuning, THz gain and absorption coefficient and the output directivity of THz wave through the arrayed Si-prism coupler, is theoretically discussed in detail. It is found that the excellent performance of LT-TPO can be achieved through the employment of the short-wavelength pump, the high pump energy and short cavity for TPO, based on the characteristics of the A1-symmetry polariton mode and the outstanding nonlinear optical properties of LiTaO3, which is then proved to be a promising candidate material for TPO. The research results provide a useful guide for the future practical operation of LT-TPO.
Anomalous phenomena of electromagnetic wave propagation in metamaterials for arbitrary orientation of optical axis
Authors: Zhou Jian-Hua  , Luo Hai-Lu  , Wen Shuang-Chun  , Fang An-Le  , Zhuang Bin-Xian  ,   (1)湖南大学计算机与通信学院微纳光电器件及应用教育部重点实验室,长沙  410082; (2)湖南大学计算机与通信学院微纳光电器件及应用教育部重点实验室,长沙  410082；邵阳学院激光技术与信息研究所，邵阳  422000
Published: December 2020

When there is an angle between the anisotropic metamaterials' optical axis and the electromagneticwave propagation axis, anomalous omnidirectional total reflection and anomalous negative refraction are discovered at the interface. The functional relation between incident angle and refractive angle of energy flow is obtained. According to this relation, we can restructure the refractive angle as negative or positive readily by selecting suitable permittivity and permeability tensors. And under these conditions, an anomalous transmittance emerges，such that when incident angle is less than a value, especially in the vicinity of vertical incident, the transmittance is minimum or even zero. According to these characteristics, a new slab spatial filter is put forward. Compared with the traditional space filter system, this new spatial filter's volume is smaller. And these characteristics can also be used to build a reflector of low spatial frequency.