bluuebunny/crossref_metadata_2025 huggingface dataset:
On physical basis of ensemble prediction
Authors: Feng Guo-Lin  , Dong Wen-Jie  ,   (1)国家气候中心，北京  100081; (2)扬州大学物理系，扬州  225009;中国科学院大气物理研究所东亚中心，北京  100029
Published: December 2020

By viewing each integral process in the ensemble prediction as a locus of quasi-particle in the nonequilibrium statistical physics theory,numerical experiments of Lorenz model are performed,and under the circumstance that the initial value of the model is near the equilibrium state of different properties,the temporal evolution of the number of quasi-particles in the ground state and the first excited state is calculated in this paper.The results confirm that if the dynamic system has stable equilibrium states in the whole phase space,the long-range temporal evolutional behavior of the system in the vicinity of the stable equilibrium states is predictable.If the dynamic system has not any stable equilibrium state in the whole phase space and the initial value of the system is far away from the unstable equilibrium states,then most of the quasi-particles lie in the low-energy state within 1-2 weeks,i.e.it is most probable.If the initial value lies in the vicinity of the unstable equilibrium states,the temporal evolution of the system is almost unpredictable.This proves theoretically that the effect of the ensemble prediction obtained after performing a large number of integral processes in better than that from the single integral process of a single init ial value.This offers a physical explanation why the ensemble prediction has a h igher accuracy.
Iterative approach of high-order scattering solution for vector radiative transfer of inhomogeneous media layer
Authors: Liang Zi-Chang  , Jin Ya-Qiu  ,   复旦大学波散射和遥感中心，信息科学与工程学院，上海  200433
Published: December 2020

By stratifying a random scattering media into thin multi-layers in z direction,the first-order scattering solution of each thin layer with Fourier transform is employed to derive high-order scattering solution of the whole random media.An iterative approach to solve high-order scattering solution of a vector radiative transfer (VRT) equation is newly developed.Numerical results are well compared with the Mueller matrix solutions of the first-order for a layer medium,second-order for a half-space,and also the results of the discrete ordinates and eigen-analysis method.It demonstrates that our approach is as feasible,effective and especially applicable to high-order solutions of VRT for both bistatic scattering and thermal emission of inhomogeneous non-spherical scattering media.
Explicit and exact solutions of the combined KdV equation
Authors: Shi Yu-ren  , Lü Ke-Pu  , Duan Wen-Shan  , Hong Xue-Ren  , Zhao Jin-Bao  , Yang Hong-Juan  ,   西北师范大学物理与电子工程学院，兰州  730070
Published: December 2020

With the aid of computer algebraic system “Mathematica” and by using the hyperbola function method,the exact and solitary wave solutions of the combined KdV equation are obtained,including the bell-like and the kink solitary wave solutions.The thought based on the hyperbola function method is extended,and more explicit and exact solutions are successfully derived,including shock wave type solutions with break point and exponential function type solutions.This method can be used also to solve other nonlinear evolution equation(s).
Synchronization of a class of chaotic systems in the presence of perturbation by an observer
Authors: Guan Xin-Ping  , He Yan-Hui  , Fan Zheng-Ping  ,   燕山大学电气工程学院，秦皇岛  066004
Published: December 2020

Synchronization problem in the presence of perturbation is considered,and the nolinear part of the chaotic system is nt in output feedback form.In this paper,we first transfer the system and obtain a nonfull order system.Second,we construct a synchronous system based on the nonlinear observer idea and realize the synchronization.Finally numerical example is illustrated and the simulation results verify the conclusion of this paper.
Control of a unified chaotic system
Authors: Tao Chao-Hai  , Lu Jun-An  ,   武汉大学数学与统计学院，武汉  430072
Published: December 2020

The paper addressed the self-feedback control,dislocation feedback control and adaptive control strategies for a unified chaotic system.The strict theoretical proof was put forward,numerical simulations were provided to show the effectiveness of these methods.The deficiency of Ref.［10］ was also corrected.
The imaging of chemical samples with a scanning near-field infrared microscope
Authors: Wang Qian  , Xu Jin-Qiang  , Wu Jin  , Li Yong-Gui  ,   中国科学院高能物理研究所,北京2732信箱，北京  100080
Published: December 2020

The imaging research of chemical samples by using a scanning near-field infrared microscope(SNIM) was described in this paper. And this microscope use Beijing Free Electron Laser as its illuminating light. Fram the SNIM image, we can make a precise decision about the sample composition and the percentage of each component in a 10μm×10μm—102μm×102μm region.
Studies on the potential energy curves of heteronuclear diatomic molecules using energy consistent method
Authors: Li Xin-Xi  , Sun Wei-Guo  , Feng Hao  ,   (1)四川大学化学工程学院，成都  610065; (2)四川大学化学工程学院，成都  610065;四川大学原子与分子物理研究所,成都  610065; (3)四川大学原子与分子物理研究所,成都  610065;四川大学物理科学与技术学院,成都  610065
Published: December 2020

The potential energy curves of some heteronuclear diatomic molecules are studies using the energy consistent method (ECM) for the electronic states of Clf-A３Π1, ClF-B0＋(３Π)，CH-X２Π，BH-X1Σ＋，XeO-d1Σ＋，LaF-X1Σ＋，Li7D-X1Σ＋，NaRb-X1Σ＋，KRb-(2)3Σ＋ and KRb-21Π. The results show that the ECM potentials are in excellent agreement with the known Rydberg-Klein-Ress(RKR) data, and are superior to the frequently used Morse potential and Huxley-Murrell-Sorbie(HMS) potential. The EGM potential can give reliable potential data at the molecular asymptote and the dissociation region where the RKR results may not be available.
Photic intensity distribution simulations of biological tissues with polystyrene spheres
Authors: Guo Hong-Lian  , Cheng Bing-Ying  , Zhang Dao-Zhong  ,   中国科学院物理研究所凝聚态物理中心光物理实验室,北京  100080
Published: December 2020

The photic intensity distributions of biological tissues which are sensitive to light such as mesophyll cell of green plant, epidermal cell of animal, compound eye of insect are simulated with single and periodically arrayed 3-μm-diameter polystyrene spheres in water. The results show that the photic intensity distributions are very different in different cross sections of spheres. Within the section of spheres, the photic intensity distributions pressent well-regulated pattern, which out of the sphere the distributions are similar to that of lens imaging. In addition, the difference of the distributions between single and periodically arrayed spheres in cross section is obvious. The distribution of the latter presents the correlativity of spheres.
Preparation of squeezed even coherence state and its nonclassical properties
Authors: Ji Ying-Hua  ,   江西师范大学物理系,南昌  330027
Published: December 2020

By keeping the frequency of non-dissipative mesoscopic LC circuit a constant and its parameter varying with the step function, the quantum state of the circuit evolves to a squeezed even coherent state from the initial even coherent state. The nonclassical properties, not only squeezing but also antibunching effects, appear in the circuit by adjusting its inductor parameter under the squeezed even coherent state.
Heat-induced undulation in the distribution of diode-pumped solid-state laser
Authors: Wang Shi-Yu  , Guo Zhen  , Fu Jun-Mei  , Cai De-Fang  , Wen Jian-Guo  , Xue Hai-Zhong  , Tang Ying-De  ,   (1)西安电子科技大学技术物理学院，西安  710071; (2)西安交通大学微波所，西安  710049; (3)西安交通大学微波所，西安  710049;西安电子科技大学技术物理学院，西安  710071
Published: December 2020

A theoretical model has been adopted to analysis the unsteady thermal effects in a laser medium. It is based on the fact that the internal dissipation power is always unequal to the heat removed from the surface. According to this, the case in a laser diode pumped solid-state laser has been studied. The result obtained shows that the fluctuations in the laser beam strongly depend on those of the temperature in the heat sink. It was also shown that the dissymmetric temperature distribution of the heat sink distorts the shape of the laser beam. A set of experiments has been carefully designed to proved these conclusions.
The analytical calculation of temperature distribution in doping processes of Zn/InP induced by continuous wave laser
Authors: Tian Hong-Tao  , Chen Chao  ,   厦门大学物理学系，厦门  361005
Published: December 2020

Based on the experiment, the process of doping of Zn/InP Indued by continuous wave laser was analysed. A brief visual analytical form of temperature distribution on a finite double-material irradiated by a continuous wave laser is presented under the third boundary condition in one-dimensional heat conduction.
Second harmonic theory of two coupled oscillators in chiral molecular media
Authors: Zheng Yang-Dong  , Li Jun-Qing  , Li Chun-Fei  ,   哈尔滨工业大学物理系，哈尔滨  150001
Published: December 2020

We have derived the hyperpolarizability of a chiral molecule from the model of coupled two-oscillators in second-harmonic generation. We gave the susecptibility of a thin film. We discussed the influence of microscopic parameters of a molecule on the efficiency of second-harmonic generation through the relationship of hyperpolarizabilities and susceptibilities. We also have simulated the spectrum of rotational angle of polarization state. Our theoretical results fit the known experimental facts.
Screening-photovoltaic solitons affected by the photovoltaic effect of a background beam
Authors: Wang Xiao-Sheng  , Ouyang Shi-Gen  , She Wei-Long  ,   中山大学光电材料与技术国家重点实验室，广州  510275
Published: December 2020

The photovoltaic effect of a background beam do not affect the spatial-charge field in a photovoltaic crystal with a constant external applied field, but has an effect on the current density in the crystal.If the crystal is connected with an external circuit which includes a resistor and a constant voltage source, the photovoltaic effect of the background beam will affect the full width at half maximum of the solitons, even switch the bright solitons, to the dark solitons, or vice versa.
Studies on the mechanism of energy transformation in implosion processes of the Z-pinches
Authors: Ning Cheng  , Yang Zhen-Hua  , Ding Ning  ,   北京应用物理与计算数学研究所,北京  100088
Published: December 2020

In this paper, the energy transformation processes in neon gas-puff pinch and Al wire-array pinch were studied numerically by means of one-dimensional three-temperature radiation magneto-hydrodynamic code. In the Z-pinch, the main energy transformation process is the Coulomb collision process between ions and electrons. The second one is the photoelectric process and bremsstrahlung radiation process. The energy transformation in the Compton scattering process can be neglected in the computation. The x-ray energy radiated from Z-pinch was produced mainly by the photoelectric excitation and recombination process, and also by the bremsstrahlung radiation process and Compton scattering process. Numerical analysis indicates that the x-ray radiation energy can be larger or smaller than the maximal plasma kinetic energy. In our numerical simulation, the radiation energy from neon gas-puff pinch is smaller than the maximal plasma kinetic energy, however, that from Al wire-array pinch is larger than the maximal plasma kinetic energy. They are all smaller than the work done by magnetic pressure. The electric energy consumed by Ohm heating is rather small.
A maser instability driven by an electron beam
Authors: Chen Yan-Ping  , Zhou Guo-Cheng  , Wu Ching-Sheng  ,   (1)中国科学技术大学地球和空间科学学院,合肥  230026;美国马里兰大学物理科学和技术研究所; (2)中国科学院国家天文台,北京  100012;中国科学院物理研究所,北京  100080; (3)中国科学院空间科学和应用研究中心,北京  100080
Published: December 2020

The theory of a maser-instabiligy driven by a beam of weakly relativistic electrons is discussed. The main purpose of this paper is to complement the derivation of the expressin for the growth rate. An approximation, which enables us to see the physics associated with the growth rate more clearly, is suggested. Moreover, some essential numerical results are also presented.
Theoretical study on nonlinear resonances of a charged micro-particle in a RF sheath
Authors: Hou Lu-Jing  , Wang You-Nian  ,   大连理工大学物理系,大连  116024
Published: December 2020

A self-consistent model is proposed here to study the nonlinear resonance and the hysteresis phenomena in the vertical oscillations of a charged micro-particle in a RF sheath. In this model, the charging process of the micro-particle and the sheath dynamics is considered self-consistently. And also, various forces acting on the particle are fully taken into account in the Newton's equations of the micro-particle. By solving the equation, we simulate the motions of the micro-particle in the sheath, under the excitations of the probe. Numerical results reproduce well the recent experimental observations; at the same time, we find that these nonlinearities are not only due to the structure of the sheath, but also due to the charging process of the micro-particle, ion drag force, neutral gas friction and the excitation of the probe.
Two fractal structures of methyl-modified Silica gels by SAXS
Authors: Xu Yao  , Li Zhi-Hong  , Fan Wen-Hao  , Wu Dong  , Sun Yu-Han  , Wang Jun  , Dong Bao-Zhong  ,   (1)中国科学院高能物理研究所同步辐射国家实验室,北京  100039; (2)中国科学院山西煤炭化学研究所煤转化国家重点实验室,太原  030001
Published: December 2020

With tetraethoxysilane ［Si(OC2H5)4，TEOS］ and methyltriethoxysilane ［CH3Si(OC2H5)3,MTES］ as precursors, two kinds of methyl-modified silica gels were prepared by the two-step method and co-hydrolysis method. The gels were tested at the small angle x-ray scattering(SAXS) Station of Beijing Synchrotron Radiation Facility(BSRF). We calculated the average particle diameter and the special surface area between the two phases. On the basis of these data the fractal characters of gels were analyzed, and two fractal structures were found in all the samples. The two fractal dimensions indicated two fractal structures on two scales, i.e., from primary SiO2 particles to first-aggregates and from first-aggregates to clusters. Aided by transmission electronic microscope(TEM) we confirmed the two different microstructures of the gels prepared using the two different methods. It can be said that SAXS is a powerful technigue to study microstructures of gel systems by studying its fractal structure.
Rapid dendritic growth in an undercooled Ni-Cu alloy under the microgravity condition
Authors: Yao Wen-Jing  , Yang Chun  , Han Xiu-Jun  , Chen Min  , Wei Bing-Bo  , Guo Zeng-Yuan  ,   (1)清华大学工程力学系,北京  100084; (2)西北工业大学应用物理系,西安  710072
Published: December 2020

Droplets of Ni-50%Cu alloy with different sizes are rapidly solidified under the condition of microgravity and containerless state within a 3m drop tube. With the increase of undercooling, the microstructural evolution has shown a transition from coarse dendrites to equiaxed grains. The maximum cooling rate of 8×103K/s and the undercooling up to 218K(014TL) are obtained in experiment. Based on a theoretic analysis, the heterogeneous nucleation occurs preferably in Ni-50%Cu droplets. The nucleation rate exceeds 1012 m-3s-1. The rapid dendritic growth of Ni-50%Cu alloy proceeds from the solutal-diffusion-controlled to the thermal-diffusion-controlled growth with the enhancement of undercooling. Under the undercooling of 68K, the segregation degree of liquid at the growing interface reaches a maximum value.
Theoretical study on defects associated with oxygen vacancy in PbWO4 crystal
Authors: Yao Ming-Zhen  , Gu Mu  ,   同济大学物理系,上海  200092
Published: December 2020

In this study, the defect associated with oxygen vacancy VO in lead tungstate crystals(PbWO4), was investigated by the relativistic self-consistent discrete variational embedded cluster method. We focused on the density state and the effect of color centre induced by VO on the surroundings. The results showed that, VO could produce the WO3+F+ defect in the crystal, and the existence of F+ could result in the absorption of 420nm. In addition, there was not F centre in the PbWO4 crystal.
A study on the electronic structure,superconductivity,and optical properties of MgCNi
Authors: Tan Ming-Qiu  , Tao Xiang-Ming  , Xu Xiao-Jun  , He Jun-Hui  , Ye Gao-Xiang  ,   浙江大学物理系，杭州  310027
Published: December 2020

In this article the density functional theory and LDA are used to study the electronic and optical properties of newly discovered alloy superconductor MgCNi3.The calculated results exhibit that the conduction bands in this compound are derived by Ni 3d and C 2p states.The top valence states have essentially Ni 3d characters and the C 2p states occupy the region from 4.0eV to 7.0eV below Fermi energy.EF locates just at the step slope of sharply structured Ni 3dyz+zx and 3d3z2-r2 peaks near ＥＦ.The doping carriers from Mg atoms destroy the magnetic order.The calculated optical properties show that the optical conductivity in the energy range 0—12eV are contributed from the Ni 3d to Ni 4s and C 2p transitions.The density of states near Fermi energy N(EF) is evaluated to be 5.50 (states/eV·cell)which yielded a Sommerfeld constant γcal～4.45mJ/mol·K2.We conclude that the mechanism of superconductivity in MgCNi3 has the type of BCS with strong electron-phonon coupling.
The ground state and persistent current of mesoscopic Aharonov-Bohm ring embedded with a quantum dot
Authors: Ye Jian-Fei  , Ye Fei  , Ding Guo-Hui  ,   上海交通大学物理系，上海  200030
Published: December 2020

An interacting quantum dot inserted in an Aharonov-Bohm ring is investigated.The explicit expression of the ground-state energy and the persistent current of the system are obtained by a second-order variational perturbation approximation method.The numerical results of the Kondo temperature and the ground-state persistent current of the system are also given under the condition that the Coulomb repulsion is infinite.
Self-assembled two-dimensional structure of magnetic cobalt nanocrystals
Authors: Shen Cheng-Min  , Su Yi-Kun  , Yang Hai-Tao  , Yang Tian-Zhong  , Wang Yu-Ping  , Gao Hong-Jun  ,   (1)北京大学电子显微境实验室，北京  100871; (2)中国科学院物理研究所纳米物理与器件实验室，北京  100080
Published: December 2020

Synthesis of monodisperse Cobalt nanocrystals by high temperature diol reduction methods in the presence oleic acid and triocethylphosphine stabilizers were reported.The mean size of the Co nanocrystals is about 14±19nm and a standard deviation of the diameter is less than 2%.The structure and the surface valency state of the Co nanocrystals were measured by XRD,Uv-vis,XPS and TEM.The monodisperse Cobalt nanocrystals can be assembled to form a two-dimensional hexagonal close-packed structure.
Studies on magnetic and magneto-optical properties of Pt976Mn26/Co multilayers
Authors: Zhou Xun  , Liang Bing-Qing  , Wang Hai  , Chen Liang-Yao  , Tang Yun-Jun  , Wang Yin-Jun  ,   (1)复旦大学物理系，上海  200433; (2)中国科学院物理研究所磁学国家重点实验室，北京  100080; (3)中国科学院物理研究所磁学国家重点实验室，北京  100080;贵州师范大学物理与电子科学系，贵阳  550001
Published: December 2020

A series of Co/Pt974Mn26(xPtMn nm)modulated multilayers with the thickness of PtMn layer x ranging from 096 to 168nm have been prepared by a magnetron sputtering system on 40nm thick PtMn buffer.With combined small-and large-angle x-ray analyses,the layered and crystal structure of the samples were investigated.Magnetic hysteresis loops and perpendicular magnetic anisotropy(PMA) were obtained by means of altermating-gradient magnetometer(AGM) and magnetic torque methods.Saturation magnetization,PMA and the Kerr spectrum of the samples were also investigated.Through analyses,we obtained the variation of Kerr rotation with the increase of PtMn thickness,which was ascribed to the reduction of the polarization of Pt atom and the interlayer alloys.
The preparation and properties of bilayer manganite films
Authors: Cha Li-Mei  , Zhang Peng-Xiang  , H.U.Habermeier  ,   昆明理工大学光电子材料研究所，昆明  650051;Max-plank-Institute,FKF,Stuttgart,Germany
Published: December 2020

The bilayer manganite film La2-2xSr1+2xMn2O7(x=032)were successfully prepared by pulsed laser deposition(PLD)method.By controlling the parameters of deposition,the fabricated films are of single phase and grown well on two kinds of substrates with different lattice constants.After measurements of transport property,it is found that there is 80K deference between the two cusp temperatures in resistivity-temperature curves(TM-I) of the two films grown on SrTiO(001) and NdGaO(110).At the same time,the resistivity of the film on SrTiO(001)is 50 times higher than that of the film on NdGaO(110).We studied the influence of the interface strain and found that the lattice mismatch between substate and film is the main reason of the above observations.Tensile strain decreases TM-I with increasing resistivity and compressed strain has an opposite effect.Using double exchange model by Zener,we found that these results can be explained qualitatively.
Photocurrent spectra of very long wavelength GaAs/AlGaAs quantum well infrared photodetector
Authors: Yuan Xian-Zhang  , Lu Wei  , Li Ning  , Chen Xiao-Shuang  , Shen Xue-Chu  , Zi Jian  ,   (1)复旦大学应用表面物理国家重点实验室，上海  200433; (2)温州师范学院物理与电子信息科学系，温州  325027; (3)中国科学院上海技术物理研究所红外物理国家实验室，上海  200083; (4)中国科学院上海技术物理研究所红外物理国家实验室，上海  200083;复旦大学应用表面物理国家重点实验室，上海  200433
Published: December 2020

The photocurrent spectra characteristics of the 15μm very long wavelength GaAs/AlGaAs quantum well infrared photo detector(QWIP) have been investigated.The two photocurrent response peaks, which have a Gaussian lineshape due to the random fluctuation of the well width,are attributed to the transitions from the ground state E0 to the first excited state E１ and the third excited state E3 in the well,respectively.The transition peaks shift linearly to higher energy as the bias across the detector increases.Taking into account electrons exchange effect,we find that the theoretical calculation using the transfer matrix method agrees well with the experimental data.
Spectroscopic properties and thermal stability of a new erbium-doped bismuth-based glass
Authors: Yang Jian-Hu  , Dai Shi-Xun  , Wen Lei  , Liu Zhu-Ping  , Hu Li-Li  , Jiang Zhong-Hong  ,   中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

The absorption spectra,emission spectra and thermal stability of Er3+-doped (85-x)Bi2O3-(10+x)B2O3-5Na2O(x=0,5,10,15,20,25 mol%)glasses were investigated in this work.The Ωt(t=2,4,6)(Ω2=(352—386)×10-20cm2,Ω4=(138—152)×10-20cm2，Ω6=(093—117)×10-20cm2)parameters were calculated by Judd-Ofelt theory.The stimulated emission cross sections(σe=(70—95)×10-21cm2)of the Er3+ ion 4I13/2→4I15/2 transition were calculated using the McCumber theory.The FWHMs(FWHM=57—79nm) of the 4I13/2→4I15/2 emission and lifetimes of 4I13/2 level(τm=265—159ms)of Er3+ ions were measured.The thermal stability of the glasses were analyzed.The compositional dependence of optical parameters of Er3+ ions were studied,with the increases of B2O3 content in the glass.The parameters Ωt(t=2,4,6),FWHM,and temperature difference of ΔT=Tx-Tg increase monotonically,while the measured lifetime decreases.The optical properties of Er3+ in different glass hosts were compared.The results show that our Er3+-doped bismuth-based glass is much more beneficial for optical amplifier to realize broadband and high gain amplification.
A new beam propagation method based on least-squares expansion approximating
Authors: Xia Jin-Song  , Yu Jin-Zhong  ,   中国科学院半导体研究所,集成光电子国家重点实验室,北京  100083
Published: December 2020

A new finite difference wide-angle beam propagation method is developed by introducing the least-squares expansion approximant in the propagator expansion- In this new method it is not necessary to select the reference index point because of the whole region approaching the lease-square expansion- This method avoids the problems induced by error selection of the reference index in the old methods based on Taylor or Padè expansion- Several typical structures are simulated by the new method and the results prove the validity of it-
The quasi-wavelet solutions of MKdV equations
Authors: Tang Jia-Shi  , Liu Zhu-Yong  , Li Xue-Ping  ,   (1)湖南大学工程力学系，长沙  410082; (2)中南大学土建学院,长沙  410075
Published: December 2020

The quasi-wavelet method is used for obtaining the numerical solution of the MKdV equation- The quasi-wavelet discrete scheme is adopted to make the spatial derivatives discrete, while the fourth-order Runge-Kutta method is adopted to make the temporal derivative discrete- One of the MKdV equation ut+6u2ux+uxxx=0, which has an analytical solution, is solved numerically- The numerical results are well consistent with the analytical solutions, even at t=10000s-
Control of chaos solely based on RBF neural network without an analytical model
Authors: Liu Ding  , Ren Hai-Peng  , Kong Zhi-Qiang  ,   西安理工大学自动化与信息工程学院, 西安  710048
Published: December 2020

An intelligent control method based on RBF neural network is proposed for chaos control- The control objective can be either periodic orbits or continuous variable functions without the need of an analytic model- The method is still effective when there are parameter perturbation and measurement noise- The influence of the RBF model error upon control precision is studied, and related theorem is developed and testified- Simulation results with a Logistic mapping and Henon attractor show the effectiveness and feasibility of this method-
A method for synchronizing chaos and hyperchaos by single driving varlable
Authors: Cheng Li  , Zhang Ru-Yuan  , Peng Jian-Hua  ,   (1)东北师范大学数学系,长春  130024; (2)东北师范大学物理系,长春  130024; (3)东北师范大学物理系,长春  130024;深圳大学理学院,深圳  518060
Published: December 2020

In order to reduce the number of signals in the process of chaotic and hyperchaotic synchronization and to improve the synchronization efficiency, we propose a method of recombining system by a linear reversible transform- After the transform, the system which could not synchronize before, achieves the synchronization with a single signal, and the efficiency of synchronization has been improved distinctly-
Ultra-narrow electromagnetically induced transparency and inversionless gain in a ladder-four-level system
Authors: Li Yong-Fang  , Sun Jian-Feng  ,   陕西师范大学物理学与信息技术学院,西安〓710062
Published: December 2020

In this paper, we study the effects of Rabi frequencies and multi-path radiation on the electromagnetically induced transparency (EIT) and the inversionless gain in a ladder- four-level system driven by two-coherent fields- The Rabi frequencies of the field-driven transition from the upper level to middle levels play an important role for the realization of the ultra-narrow EIT and inversionless gain- Different excitation mechanism can change the position of the EIT- The action of the spontaneous alignment of the dipole moment is investigated- The explanation for the numerical results is presented using the theory of dressed state
Influence of relaxation and correlation effects on probabilities of the 2s22p3s 3P1—2s22p21D2 and 2s22p3s 1P1—2s22p23P0,1,2 intercombination transitions in NII
Authors: Yuan　Ping  , Liu　Xin-Sheng  , Zhang　Yi-Jun  , Xie　Lu-You  , Dong　Chen-Zhong  ,   (1)西北师范大学物理与电子工程学院，兰州  730070; (2)西北师范大学物理与电子工程学院，兰州  730070;中国科学院寒区旱区环境与工程研究所，兰州  730000; (3)中国科学院寒区旱区环境与工程研究所，兰州  730000
Published: December 2020

The transition probabilities for the intercombination lines of 2s22p3s 3P1—2s22p21D2 and 2s22p3s 1P1—2s22p23P0,1,2 in NII have been calculated by using a large-scale multi-configuration Dirac-Fock method- In the calculation the most important effects of relativity, correlation, and relaxation are considered- The strong influence of correlation and relaxation effects on the transition probabilities have been confirmed by a compared calculation- When taking into account these effects in calculations, a remarkable improvement is found- From the results, the intensity of the 2s22p3s 3P1—2s22p21D2 line is supposed to be smaller than the previous theoretical prediction-
Numerical study of tie spatially induced group velocity dispersion
Authors: Hu Wei  , Lu Guang-Shan  , Yang Zhen-Jun  , Guo Hong  , Liu Cheng-Yi  ,   华南师范大学传输光学实验室，广州  510631
Published: December 2020

We have studied, by numerical simulations, the spatially-induced group velocity dispersion in the propagation of ultrashort-pulsed Bessel beams in free space- The simulation results have confirmed the existence of the spatially-induced dispersions in the propagation of a truncated Bessel beam which can be constructed in practice- It is shown that the spatially-induced dispersion is observed when the diffraction length of truncated Bessel beams is longer than the dispersion length of spatially-induced group velocity dispersion-
Nonlinear optical properties of insulator inclusions/liquid host composite media
Authors: Gao Lei  , Hong Gang  ,   (1)苏州大学物理系，苏州  215006; (2)苏州大学物理系，苏州  215006;南京大学固体微结构物理国家重点实验室，南京  210008
Published: December 2020

The effective optical properties have been investigated in granular insulator/liquid host composite media- In the weak nonlinearity limit, we calculate numerically the effective linear dielectric function (ε0e) and optical nonlinearity (χe) as functions of the volume fraction of insulator inclusions (f)-The results show that χe can be achieved at a resonant frequency ω≈32- In the general nonlinear case, we study how the intensity of incident light affects the effective dielectric function- Furthermore, the total effective refectances of s-and p-polarized light are investigated-
Numerical studies of characteristics and the design of 1PW optical parametric chirped pulse amplifier for the “Shenguang-Ⅱ” facility
Authors: Zhu Peng-Fei  , Qian Lie-Jia  , Xue Shao-Lin  , Lin Zun-Qi  ,   (1)复旦大学光科学与工程系,上海  200433; (2)上海交通大学物理系,上海  200240; (3)中国科学院高功率激光物理国家重点实验室,上海光学精密机械研究所,上海  201800
Published: December 2020

In this paper, the characteristics of optical parametric chirped pulse amplification(OPCPA) are numerically studied by a computer- The infection of the group velocity mismatch, the phase-velocity mismatch, and the cubic nonlinearity in the process of amplification has been discussed respectively- The comparison between the OPCPA and the chirped-pulse amplification(CPA) is made, such as of the mechanism of amplification, the synchronization, the red-shift phenomenon, the gain-narrowing effect, and so on- To realize the fast ignition of inertial confinement fusion, we have designed an OPCPA system for the “Shenguang-Ⅱ” facility, which can generate pulse with a duration as short as 50fs and a power of multi-petawatt-
The condition for forming a polychromatic light photovoltaic spatial soliton and its application
Authors: Wang Xiao-Sheng  , She Wei-Long  ,   中山大学光电材料与技术国家重点实验室，广州  510275
Published: December 2020

We discuss the conditions under which some polychromatic light photovoltaic spatial solitons can be formed in a photorefractive crystal with a positive perturbation refractive index- Generally, under these conditions we can form bright-bright,dark-dark and bright-dark polychromatic light photovoltaic spatial solitons in the crystal- In the case of bright-bright solitons, if we launch a monochromatic beam(ray2,its effective Glass constant is less than that of the background), bright soliton cannot be obtained- But if we add another monochromatic beam(ray1, its effective Glass constant is larger than that of the background beam), both ray1 and ray2 can form bright solitons under some condition- This gives a new way to control ray2 with ray1- It is shown that the width of bright-bright solitons can be modified by the peak intensity of ray1-
Implementation of complete two-dimensional bandgap in photonic crystals of square Bravais lattice using complex unit cell
Authors: Qiu Gao-Xin  , Lin Fang-Lei  , Li Yong-Ping  ,   (1)中国科学技术大学物理系，合肥  230026; (2)中国科学技术大学物理系，合肥  230026;中国科学技术大学结构分析开放实验室，合肥  230026
Published: December 2020

In two-dimensional photonic crystals of square Bravais lattice, complex unit cell was considered to achieve a complete bandgap- By adding an optimal algorithm in our calculation, the structure parameters of photonic crystals with the largest complete two-dimensional bandgap were obtained-
Optical transmission enhancement of two-dimensional subwavelength hole arrays in metallic films
Authors: Yi Yong-Xiang  , Wang Guo-Ping  , Long Yong-Bing  , Shan Hong  ,   (1)武汉大学计算机学院，武汉  430072; (2)武汉大学物理系，武汉  430072
Published: December 2020

Numerical simulation has been performed on the optical transmission enhancement of a metallic film with a two-dimensional subwavelength hole array- The results show that the ideal conducting film of the same array structure also presents a transmission enhancement, but the enhancement is not higher than that of the real one- Further analysis reveals that a complicated waveguide coupling effect is responsible for the enhanced transmission- The excitation of surface current on metallic surface transfers the light energy of incidence from metallic surfaces to the holes and then adjusts the optical transmission- We believe that the resonant excitation of surface plasmon is not necessary for the enhancement effect-
Experimental and theoretical study on the compound dual-period fibre grating
Authors: Wang Mu-Guang  , Wei Huai  , Jian Shui-Sheng  ,   北方交通大学光波技术研究所，北京  100044
Published: December 2020

In this paper we design a novel compound dual-period fibre grating structure, and analyze its spectrum response using the coupled mode theory- The simulation result is compared with the experiment,and it is shown that the model is correct- We also apply it in a temperature and strain sensor system-
Research on the 4×10Gb/s 400km dispersion compensation by chirped optical fibre grating
Authors: Pei Li  , Jian Shui-Sheng  , Yan Feng-Ping  , Ning Ti-Gang  , Jian Wei  , Li Tang-Jun  ,   北方交通大学光波技术研究所，北京100044
Published: December 2020

In this paper, we introduce the successful dispersion compensation of 4×10Gb/s 400km G-652 fibre by chirped optical fibre Bragg grating- When BER is 10-10, the power penalty of transmission in each channel is less than 2dB, and the best result is negative-
A new numerical method for simulating fluid flow through porous media
Authors: Xu You-Sheng  ,   浙江师范大学物理系,金华  321004
Published: December 2020

A new numerical method is developed for simulating fluid flow through the porous media based on the lattice Boltzmann method-No measure is adopted on the boundary,and no nonphysical by-product is produced at the same time-The numerical result also agrees well with the exact solution, therefore the model is considered to be reliable-
Analysis of activated carbon from city solid waste by small angle x-ray scattering
Authors: Rong Li-Xia  , Xie Li-Ping  , Dong Bao-Zhong  , Lin Wei-Gang  , Wang Jun  ,   (1)中国科学院高能物理研究所,北京  100039; (2)中国科学院过程工程研究所,北京  100080
Published: December 2020

The structure of activated carbon prepared from city solid wastes under different conditions was investigated by synchrotron radiation small angle x-ray scattering- Our results demonstrate that the structure of the activated carbon depends on the component of the carbonized residua, the carbonized conditions, etc-
Pore structures of methyl-modified silica xerogels by small angle x-ray scattering
Authors: Xu Yao  , Li Zhi-Hong  , Fan Wen-Hao  , Wu Dong  , Sun Yu-Han  , Wang Jun  , Dong Bao-Zhong  ,   (1)中国科学院高能物理研究所同步辐射实验室,北京  100039; (2)中国科学院山西煤炭化学研究所煤转化国家重点实验室,太原  030001
Published: December 2020

Two kinds of methyl-modified silica xerogels were prepared by mixing SiO2 colloidal suspension deriving from basic-catalyzed hydrolysis of TEOS (tetraethoxysilane) and siloxane polymer solution prepared from acid-catalyzed hydrolysis of MTES (methyltriethoxysilane) or DDS (dimethyldiethoxysilane). The xerogels were tested at the small angle x-ray scattering (SAXS) station of Beijing Synchrotron Radiation Facility. The distribution of pore size, the average size of pores DSAXS, and the thickness of interface layer E were calculated. With the aid of nitrogen adsorption measurement, the pore structure was analyzed. Some micropores were found to be produced in methyl-modified SiO2 xerogels while second-aggregates were constructed through connecting first-aggregates with siloxane polymer of MTES or of DDS. At the same time, methyl groups were attached to the bone of SiO2 clusters and become an interface layer between bone and pore. The interface layer have effects on both pore size and the adsorption of nitrogen in methyl-modified xerogels. Through transmission electron microscope we confirmed that the pore structures of the xerogels were affected strongly by the two different siloxane polymers. SAXS is a powerful technique to study pore structure of xerogel system.
Structural and magnetic properties of (Nd1-xErx)3Fe273Ti17 compounds
Authors: Wang Wen-Quan  , Yan Yu  , Wang Xiang-Qun  , Wang Xue-Feng  , Jin Han-Min  ,   (1)吉林大学物理学院,长春  130023; (2)吉林大学物理学院,长春  130023;吉林大学超硬材料国家重点实验室,长春  130023
Published: December 2020

Structural and magnetic properties of (Nd1-xErx)3Fe273Ti17 compounds have been investigated by means of x-ray diffraction and magnetic measurements. All the compounds with x in the range of 00—05 crystallize in a Nd3(Fe,Ti)29-type structure. Substitution of Er for Nd leads to a contraction of unit-cell volume. Curie temperature TC of the (Nd1-xErx)3Fe273Ti17 compounds decreases monotonically with increasing Er content. Saturation magnetization Ms of the (Nd1-xErx)3Fe273Ti17 compounds decreases with increasing x. As temperature decreases from room temperature to 5K, a spin reorientation from easy plane to easy cone occurs for (Nd1-xErx)3Fe273Ti17 compounds. The anisotropy field Ba for(Nd1-xErx)3Fe273Ti17 compounds decreases with increasing Er content. Spin-phase diagrams have been constructed for (Nd1-xErx)3Fe273Ti17 compounds.
Structural and magnetic properties of Gd3 Co29-xCrx compounds
Authors: Wang Wen-Quan  , Yan Yu  , Wang Xiang-Qun  , Wang Xue-Feng  , Su Feng  , Jin Han-Min  ,   (1)吉林大学物理学院,长春  130023; (2)吉林大学物理学院,长春  130023;吉林大学超硬材料国家重点实验室,长春  130023
Published: December 2020

The novel Co-based Gd3Co29-xCrx compounds with a Nd3(Fe,Ti)29-type structure have been synthesized successfully for x=65 and 70 The crystal structure and magnetic properties of the Gd3Co29-xCrx compounds have been investigated by x-ray diffraction analysis and magnetic measurements. It has been found that Gd3(Co,Cr)29 with x=65 and 70 are ferrimagnetic with the Curie temperature of 412 K for x=65 and 359 K for x=70. Temperature dependence of magnetization shows a compensation point of the magnetization at a certain temperature below Curie point. The intersublattice molecular field coefficient, nRT, was derived to be 33 T f.u./μB for Gd3Co225Cr65 on the basis of the magnetization curve at the compensation temperature. It is noteworthy that the Gd3(Co,Cr)29 compounds exhibit a favourable easy-axis anisotropy in the whole temperature range below the Curie temperature.
Bundle structure formation on polymer film by varying temperature AFM scanning
Authors: Wang Xiao-Ping  , Shi Qin-Wei  ,   (1)中国科学技术大学结构分析开放实验室,合肥  230026; (2)中国科学技术大学物理系,合肥  230026;中国科学技术大学结构分析开放实验室,合肥  230026
Published: December 2020

The bump and bundle structures formed by atomic force microscopic tip scanning on 133nm thick PtBuA films were examined from room temperature to 58℃ with various scanning velocities of 1—20μm/s. It was observed that the bump structures were readily created at low temperature and high scanning velocity, while the bundles were created at high temperature and low scanning velocity. The period of bundles was about 100nm. The effects of temperature and scanning velocity could be explained by the equivalence of temperature and time of viscoelasticity of the polymer. The roughness increased with the scanning numbers at low temperatures while kept almost the same at high temperatures. All the above results indicated that the bump and bundle structure could be formed more frequently on the polymer surface at glassy state due to its larger modulus, smaller adhesion and weaker relaxation, as compared to its rubber state.
A study of the band structure in two-dimensional phononic crystals based on plane-wave algorithm
Authors: Qi Gong-Jin  , Yang Sheng-Liang  , Bai Shu-Xin  , Zhao Xun  ,   国防科技大学航天与材料工程学院，长沙  410073
Published: December 2020

In this paper, the calculating course of the plane-wave algorithm is introducedto solve the sound wave equation and the band structure of phononic crystals. The phononic crystals of two-dimensional binary liquid systems are studied. In conclusion, the CCl4/mercury system is easier to obtain the band-gap than the mercury/CCl4 system. With the increase of the filling fraction(f), the width of the band-gap becomes wider and then narrower. The widest band-gap of CCl4/mercury system appears at f=0229,where ΔΩmax=0549.While the width of the band-gap in mercury/CCl4 system increases consistently with the filling fraction, when f=0.554,ΔΩmax=0515.Under the same filling fraction, the variation of the cylinder diameter and lattice constant does not affect the band-gap width ΔΩ.
Investigation of the influence of directional internal stress on the arrangement of martensitic variants
Authors: Li Yang-Xian  , Meng Fan-Bin  , Liu He-Yan  , Qu Jing-Ping  , Wang Wen-Hong  , Cui Yu-Ting  , Liu Zhu-Hong  , Chen Jing-Lan  , Wu Guang-Heng  ,   (1)河北工业大学材料学院，天津  300130; (2)中国科学院物理研究所磁学国家重点实验室，北京  100080
Published: December 2020

Microstructure and magnetic measurements were performed to reveal the distribution of the internal stress in single crystals of Ni2MnGa.It was suggested that due to the existence of the directional internal stress in the growth direction of single crystals results in the perfect arrangement of martensitic variants along the growth direction.Furthermore,the influence of such a perfect arrangement of variants on the formation of magnetic domain was studied in this paper.
Investigations of three-terminal electronic measurement on quantum dot devices
Authors: Zhu Yun  , Wang Tai-Hong  ,   中国科学院物理研究所，北京  100080
Published: December 2020

Theree-terminal electronic measurements have been performed on quantum devices with a modulation-doped two-dimensional(2D) electron gas structure.The resistance with the 2D electron gas and that with the tunnel resistance through the dots can be obtained by analyzing the experimental data.Our results show that the lateral coupling between the quantum dots mainly determine the transport properties of the quantum dot devices under small biases.
Silicon nitride films prepared by helicon wave plasam-enhanced chemical vapour deposition
Authors: Yu Wei  , Liu Li-Hui  , Hou Hai-Hong  , Ding Xue-Cheng  , Han Li  , Fu Guang-Sheng  ,   河北大学物理科学与技术学院，保定  071002
Published: December 2020

Silicon nitride films(SiN) are deposited by helicon-wave plasma-enhanced chemical vapour deposition(HWP-CVD) under the condition that a gas mixture of SiH4 and N2 is required.The influence of experimental parameters on the properties of the sample films is investigated.The parameters such as bond structure,thickness and refractivity of SiN films are measured by using Fourier transform infrared(FTIR) spectroscopy,ultraviolet-visible spectroscopy and ellipsometer detection technique.Results show that SiN films with a low hydrogen content can be prepared by HWP-CVD at a higher rate and lower substrate temperature,and the main bond mode in the deposited SiN films is Si—N stretching mode.At lower reactive gas pressure,the deposition rate is promoted and the density of the sample films increases.The appropriate increase in N2/SiH4 ratio is beneficial to the decrease of the H content in SiN films.
Influences of an external pulse on the quantum state of a mesoscopic RLC circuit
Authors: Ji Ying-Hua  ,   江西师范大学物理系，南昌  330027
Published: December 2020

In this paper, the influences of an external pulse on the variation of the quantum state of a mesoscopic RLC circuit are investigated emphatically. Our research result indicates that the transition probabilities of the variation of the quantum state are adjusted by controlling the variation of the pulse parameters when the parameters of the mesoscopic circuit are constant. We point out that the quantum state of a system is stable when the width of the pulse is equal to the integral times of the minimum fixed value. The minimum fixed value is not related to the altitude of pulse but the circuit parameters. The larger the resistance, the wider the minimum fixed width of the external pulse.
The study of domain-wall pinning by inhomogeneities in nanocrystalline permanent magnets
Authors: Rong Chuan-Bing  , Zhang Hong-Wei  , Zhang Jian  , Zhang Shao-Ying  , Shen Bao-Gen  ,   中国科学院物理研究所与凝聚态物理中心磁学国家重点实验室，北京  100080
Published: December 2020

The coercive force of the domain-wall pinning model can be expressed as Hc=αpink2K1/μ0Ms-NeffMs. The dependences of the microstructure parameter αpink on the exchange and anisotropy constants of inhomogeneities are discussed in this paper. The results show that there is a wide range of the αpink values. The effects of magnetic parameter and thickness of Nd2Fe14B grain boundary on the αpink are also studied. It was found that αpink reaches the maximum where A′/A=0.5,K′1/K1=0.1 and the grain-boundary thickness r0=3.32nm. αpink of nanocomposite Nd2Fe14B/α-Fe magnets reaches the maximum when the grain size r0 is 7nm.
Methods for preventing magnetic deviation saturation of high power amorphous transformer
Authors: Sun Mei-Sheng  , Xu Xiao-Peng  , Lu Wei  , Fang Xing-Hao  ,   清华大学自动化系，北京  100084
Published: December 2020

This paper summarizes the basic characteristics of amorphous materials, and thoroughly analyses the reason why magnetic deviation saturation occurs in high-power amorphous transformers. And also, the incremental amplitude method, the incremental pulse width method, the current integral pulse width adjustment method and some other methods are proposed to prevent magnetic deviation saturation.
Dielectric，elastic and piezoelectric properties of La3Ga5SiO14 crystal
Authors: Li Zheng-Fa  , Zhang Pei-Lin  , Zhao Ming-Lei  , Wang Chun-Lei  , Zhong Wei-Lie  , Wang Zeng-Mei  , Yuan Duo-Rong  ,   (1)山东大学晶体材料国家重点实验室，济南  250100; (2)山东大学物理与微电子学院，济南  250100
Published: December 2020

The dielectric，elastic and piezoelectric properties of the La3Ga5SiO14 crystal have been investigated. Its elastic and piezoelectric constants were measured by the resonant method through high-frequency vibration mode.
The luminescence of Er3+,Yb3+,Tm3+-codoped tellurite glass pumped at 970nm
Authors: Dai Shi-Xun  , Yang Jian-Ｈu  , Liu Zhu-Ping  , Wen Lei  , Hu Li-Ｌi  , Jiang Zhong-Hong  ,   (1)中国科学院上海光学精密机械研究所，上海  201800; (2)中国科学院上海光学精密机械研究所，上海  201800;华南理工大学光通讯材料研究所，广州  510641
Published: December 2020

The fluorescence and up-conversion spectrum of Er3+/Yb3+, Tm3+/Yb3+, Er3+/Yb3+/Tm3+-codoped tellurite glasses pumped by a 970nm laser diode has been studied. The lifetimes of Er3+:4I11/2 and Er3+: 4I13/2 levels have been measured. It is found that the fluorescence width in the range of 1450—1700nm in Er3+/Yb3+/Tm3+-codoped tellurite glass has been broadened clearly. There is a fluorescence peak at 1630nm which is probably due to Tm3+:1G4→3F2 transitions in Er3+/Yb3+/Tm3+-codoped tellurite glass. Up-conversion phenomena exist in all the three kinds coped tellurite glasses because of its lower phonon energy of host. The addition of Tm3+ in Er3+/Yb3+-codoped tellurite glasses quenches the up-conversion efficiency of Er3+:4S3/2 green and Er3+:4F9/2 red emissions. The quenching effect is due to the energy transfer between Er3+ and Tm3+, especially the cross-relaxation process among them.