bluuebunny/crossref_metadata_2025 huggingface dataset:
THERMODYNAMICS OF A SUPERRADIANCE WITH A CLUSTER EXPANSION
Authors: LIU WEN-SEN  , LI XIU-PING  , ZHANG YUN-BO  , LIANG JIU-QING  ,   (1)山西大学物理系，太原  030006; (2)山西大学物理系，太原  030006;中国科学院物理研究所，中国科学院凝聚态物理中心，北京  100080
Published: November 2020

N-atom single-mode radiation field interaction system is regarded as an interacting quasi-boson-photon system and is treated as a grand canonical ensemble.The explicit expression for the thermodynamical potential of the system is obtained using cluster expansion method.Some thermodynamic quantities are derived in terms of the general thermodynamic formulas.The numerical calculation and diagrams exhibit the thermodynamic behavior of the system.The singularities appearing in the critical line and other places furnish evidences of existence of the second kind of phase transformation in this collective system.
A STUDY OF OPTICAL OSCILLATOR STRENGTHS AND DIFFERENTIAL CROSS SECTIONS IN THE DISCRETE REGION OF CARBON MONOXIDE
Authors: ZHONG ZHI-PING  , WU SHU-LAN  , XU ZHENG  , ZHU LIN-FAN  , ZHANG XIAO-JUN  , FENG REN-FEI  , XU KE-ZUN  ,   中国科学技术大学近代物理系，合肥  230027
Published: November 2020

The absolute optical oscillator strength density spectrum of carbon monoxide has been measured at an impact energy of 1.5keV and a mean scattering angle of 0° in an energy region of 7—21eV with typical FWHM 60meV. The absolute optical oscillator strengths corresponding to vibrational levels of A1Π,B1Σ+，C1Σ+ and E1Π are determined and compared with previous experimental and theoretical results. The reason why discrepancies exist among experimental results obtained by various methods has been explained and the limitation of dipole (e,e) method in determining optical oscillator strengths has been discussed.
CONFINEMENT OF ELECTRON BEAMS BY MESH ARRAYS IN A RELATIVISTIC KLYSTRON AMPLIFIER
Authors: WANG PING-SHAN  , YU SHAO-YING  , LEI FANG-YAN  , LUO MIN  , MA QIAO-SHENG  , TAN JIE  , GU BIN-LIN  ,   (1)清华大学现代应用物理系，北京  100084; (2)清华大学现代应用物理系，北京  100084;应用电子学研究所，成都  610003; (3)应用电子学研究所，成都  610003
Published: November 2020

Theoretical and experimental results of intense beam confinement by conducting meshes in a relativistic klystron amplifier (RKA) are presented.Electron motions in a steady intense electron beam confined by conducting meshes are analyzed with an approximate space charge field distribution. And the conditions for steady beam transportation are discussed.Experimental results of a long distance (60cm) transportation of an intense beam (400kV,2.5kA) generated by a linear induction accelerator are presented.Experimental results of modulated beam transportation confined by the mesh array are presented also.The results show that the focusing ability of the conducting meshes is not very sensitive to the beam energy.And the meshes can be used effectively in a RKA to replace the magnetic field system.
DIFFUSION AND REACTION-LIMITED FRACTAL AGGREGATION WITH FINITE STEPS
Authors: WU FENG-MIN  , ZHU QI-PENG  , SHI JIAN-QING  , WU ZI-QIN  ,   (1)浙江工业大学，杭州  310014; (2)中国科学技术大学基础物理中心，合肥  230026
Published: November 2020

By taking into account the influence of the concentration of particles n,diffusive range Δ,the probability of reaction P and maximum diffusive steps W,the diffusion and reaction-limited aggregation with finite steps model is presented.The varied patterns of aggregation and their fractal dimension are obtained under condition of nearest-neighbor.The results show that the form of aggregation is discrete cluster at lower n.However,the growth morphologies change from discrete cluster to continuous dendrite with the increase of P or W at higher n.
PERTURBATIVE ANALYSIS OF PHOTOREFRACTIVE MOVING GRATING AT LARGE MODULATION DEPTHS
Authors: FENG YU-WEN  , ZHOU ZHONG-XIANG  , JIANG YONG-YUAN  , SUN XIU-DONG  , XU KE-BIN  ,   哈尔滨工业大学应用物理系，哈尔滨  150001
Published: November 2020

We have discussed the recording of moving grating in photorefractive materials at large modulation depths using hopping model.The analytical expressions of the first three-order spatial charge field are presented which describe the nonstatic recording of the moving fringes.And the dependence of the space charge field on the veloctiy of the moving fringes is discussed for non diffusive field.We found that the higher-order harmonics of the space charge field for low diffusive field can be selectively enhanced with applied small dc field.Otherwise,they cannot be selectively enhanced if the diffusive field is large than the applied electric field.
THEORETICAL AND EXPERIMENTAL STUDY ON COMPRESSION OF CHIRPED OPTICAL PULSES UTILIZING DISPERSION-COMPENSATION AND HIGH-ORDER SOLITON EFFECT
Authors: WU JIAN  , LOU CAI-YUN  , LI YU-HUA  , GAO YI-ZHI  ,   清华大学电子工程系，北京  100084
Published: November 2020

In this paper,we study theoretically and experimentally the compression of chirped optical pulses in dispersion-compensation fiber and dispersion-shifted fiber utilizing single mode rate equation of semiconductor laser and nonlinear Schrdinger (NLS) equation.In experiment,the 53.8ps pulses generated by a gain-switched DFB semiconductor laser diode with 2.5GHz repetition rate were compressed to 12ps in a length of dispersion-compensation fiber.Then,the 12ps pulses were compressed to 2.5 or 2.1ps due to high-order soliton effect in dispersion-shifted fiber.Experimental results agree with theoretical results.
COMPARISON BETWEEN THE INTERNAL FRICTION VALUES OF THE SPECIMEN AND THE VIBRATION SYSTEM
Authors: SHUI JIA-PENG  , LIU YONG-SONG  , PEI HUI-YUAN  ,   中国科学院固体物理研究所内耗与固体缺陷开放研究实验室，合肥  230031
Published: November 2020

The expressions of internal friction values of four mechanical models and corresponding vibration systems have been deduced.The relationships between the internal friction values of the specimen and the vibration system for two-parameter models and two models of the standard anelastic solid have been obtained.It is found that these relationships for different models or the materials of different mechanical properties are different.
RESONANT TUNNELING THROUGH NANO-SIZE QUANTUM DOT EMBEDDED IN AMORPHOUS TISSUES
Authors: LIU MING  , WANG ZI-OU  , HE YU-LIANG  , JIANG XING-LIU  ,   北京航空航天大学应用物理系，北京  100083
Published: November 2020

The diode consisting of nano-silicon quantum dots embedded in an amorphous silicon matrix was fabricated and the discontinuous staircases on its I-V curves were observed.There were two distinct regimes on I-V curves of diode:(i) the sequential tunneling regime,where current increased monotonously with increasing negative bias;(ii) the resonant tunneling regime,where the current increased dramatically with increasing negative bias,and three quantum staircases appeared.It was found that the steps was related to the grains of the deposited film.The qualitative explanation of this physical phenomenon was proposed in terms of the material structural characteristics.
INTERFACIAL REACTION BETWEEN Ti THIN FILM AND AlN CERAMIC
Authors: WANG YOU-XIANG  , YUE RUI-FENG  , CHEN CHUN-HUA  ,   中国科学院半导体研究所，北京  100083；中国科学院表面物理国家重点实验室，北京  100080
Published: November 2020

A 200nm Ti film was deposited on a polished AlN ceramic substrate at 200℃ by electron beam evaporation under high vacuum conditions and annealed in a vacuum furnace.X-ray diffraction measurement and secondary ion mass spectrometry,Rutherford backscattering spectrometry,Auger electron energy spectroscopy were used to investigate the solid phase reactions between the titanium thin film and the AlN ceramic substrate during annealing from room temperature to 850℃.Experimental results showed that after annealing beyond 600℃,diffusion and reaction took place at the interface of Ti/AlN obviously and the reaction was enhanced with increasing temperature.The titanium aluminides and titanium nitrides as reaction products at the interfaces have been found.The titanium aluminides consist of Ti-Al binary and Ti-Al-N ternary compounds,in which Ti2AlN is dominant after 4h annealing at 850℃.The results have been explained in terms of extended Ti-Al-N ternary phase diagram given by Bhansali et al.
HREM STUDY OF THE INTERFACIAL STRUCTURE OF NiFe/Mo MAGNETIC MULTILAYERS
Authors: GAO YI-HUA  , ZHANG ZE  , YAN MING-LANG  , LAI WU-YAN  ,   (1)中国科学院北京电子显微镜实验室与凝聚态物理中心，北京  100080; (2)中国科学院物理研究所磁学国家重点实验室，北京  100080
Published: November 2020

The ［(Ni80Fe20)1.4nm/Moxnm］30 magnetic multilayers(x=0.7,1.6,2.1) have been investigated by selected area electron diffraction and high resolution electron microscopy (HREM).It is revealed that:(a) The structure of the NiFe/Mo multilayer changes with the increase of the thickness of Mo spacer-layer. The NiFe and Mo layers are mainly amorphous as the Mo spacer is 0.7 nm in thickness, and crystallized into polycrystalline fcc NiFe and bcc Mo layers as the Mo spacer is thicker than 1.6nm. (b) For the multilayers with Mo spacer of 1.6nm and 2.1nm in thickness , there are two types of orientation relationship between the fcc NiFe and bcc Mo:(110)Mo∥(111)NiFe，［111］Mo∥［110］NiFeand(110)Mo∥(111)NiFe，［001］Mo∥［110］NiFe.(c) The NiFe /Mo interfaces are sharp in case (b) but the lattice spacing varies near the interface region as the lattice spacing of NiFe expands and that of Mo contracts with respect to their bulk counterparts. The variation of lattice spacing near the interfacial region has been discussed and the absence of giant magneto-resistance has been interpreted by the structural characteristics of the multilayers.
DEPENDENCE OF THE AB INITIO VACANCY FORMATION ENERGY IN METAL ALUMINUM ON THE UNIT CELL SIZE
Authors: ZHU ZI-ZHONG  ,   厦门大学物理系，厦门  361005
Published: November 2020

The vacancy formation energy in metal Al have been computed by a first-principles pseudopotential method. The dependence of the calculated vacancy formation energy on the supercell size and k point sampling set have been studied in detail. Our results show that the atomic sites in the supercell should reach about 100 in order to have a convergent theoretical value for the vacancy formation energy in Al. The theoretical value using a supercell of 108 atomic sites is in excellent agreement with experimental data.
STUDY OF ELECTRICAL AND OPTICAL PROPERTIES OF METALLIC CLUSTERS EMBEDDED IN ORGANIC THIN FILM (II)
Authors: OUYANG MIN  , HOU SHI-MIN  , LIN LIN  , LIU WEI-MIN  , XUE ZENG-QUAN  , WU QUAN-DE  , XIA ZONG-JU  , ZOU YING-HUA  ,   (1)北京大学电子学系，北京  100871; (2)北京大学物理系，人工微结构和介观物理国家重点实验室，北京  100871
Published: November 2020

The electrical bistability of the two kinds of complex thin films Ag-TCNQ and Ag-BDCB was discussed,which were films of metallic clusters embedded in π-conjugated organic media.And infrared spectroscopy was applied to the study of the mechanism.The pump-probe method was used to study the transient response of these two kinds of thin films, the therotical analysis demonstrates that the transient response can be associated with the electrical stability qualitatively.
STUDY ON THE STRUCTURE OF a-C∶H(N) FILMS BY XPS
Authors: CHENG YU-HANG  , WU YI-PING  , CHEN JIAN-GUO  , QIAO XUE-LIANG  , XIE CHANG-SHENG  , YANG YE-ZHI  , MUO SHAO-BO  ,   (1)华中理工大学塑性成型模拟及模具技术国家重点实验室，武汉  430074; (2)武汉大学分析测试中心，武汉  430072
Published: November 2020

The a-C∶H(N) films was deposited from the mixture of C2H2 and N2 by rf-dc plasma enhanced chemical vapor deposition. The influence of N2 percentage in the mixture on the composition and structure of a-C∶H(N) films was studied by XPS. As the N2 percentage in the feed gas was increased from 0% to 75%, up to 9.09% N was incorporated in the film. The results of analysing C1s and N1s core level indicated that a-C∶H(N) films are consisted of stoichiometry C3N4 phase and CHx matrix which is identified as predominantly sp2 bonded structure. The N/C ratio of C3N4 phase is near 4/3. The N atoms incorporated in the films is useful to increase the content of C3N4 phase and sp3/sp2 ratio.
ELLIPSOMETRIC STUDY OF THE MEDIUM-RELATED DIELECTRIC FUNCTIONS OF NOBLE METALS
Authors: XU BO  , CHEN LIANG-YAO  , WANG YU  , ZHANG RONG-JUN  , ZHENG WEI-MIN  , QIAN DONG-LIANG  , ZHENG YU-XIANG  , YANG YUE-MEI  , ZHOU SHI-MING  , DAI NING  , DING KOU-BAO  , ZHANG XIU-MIAO  ,   (1)复旦大学物理系，上海  200433; (2)杭州大学电子工程系，杭州  310028
Published: November 2020

To study the influence on the optical properties of metal imposed by neighboring medium,we used Dove prisms with different refractive indexes as the substrate in experiment.The noble metal films of Au and Ag were deposited on the bottom of prisms.The dielectric functions for films at the metal-air and metal-substrate interfaces were measured by the spectroscopic ellipsometric method.We found that the dielectric functions of the film measured at the metal-substrate interface do change with the refractive index of the neighboring medium and differ from that measured at the metal-air interface in both the Drude and interband transition regions.The results obtained in a solid-contacting configuration agree with those observed by other authors in a liquid-contact condition,however they cannot be well understood by the known mechanisms.
CHARACTERISTIC ELECTRON ENERGY LOSS SPECTRA IN SiC BURIED LAYERS FORMED BY C+ IMPLANTATION INTO CRYSTALLINE SILICON
Authors: YAN HUI  , CHEN GUANG-HUA  , S.P.WONG  , R.W.M.KWOK  ,   (1)北京工业大学应用物理系，北京  100022; (2)香港中文大学电子工程系，香港沙田; (3)香港中文大学化学系，香港沙田
Published: November 2020

SiC buried layers were snythesized by a metal vapor vacuum arc ion source,with C+ ions implanted into crystalline Si substrates.According to X-ray photoelectron spectroscopy,the characteristic electron energy loss spectra of the SiC buried layers were studied.It was found that the characteristic electron energy loss spectra depend on the profiles of the carbon content,and correlate well with the order of the buried layers.
SOME PROPERTIES OF SUPERGAUSSAN PURE STATES
Authors: YAN KE-ZHU  , KONG XIANG-HE  , XIA YUN-JIE  ,   曲阜师范大学物理系，曲阜  273165
Published: November 2020

We introduce a kind of quantum pure statessupergaussan pure states, in which the coordinate probability density distribution is between the gaussian distribution and rectangle distribution. Some properties of quantum mechanics, squeezing, higher-order squeezing and Shannon's entropy in this state are studied. The relation between squeezing and Shannon's entropy is also discussed.
EFFECT OF FINITE BANDWIDTHS OF LASER FIELDS ON ELECTROMAGNETICALLY INDUCED TWO-PHOTON TRANSPARENCY AND ABSORPTION ENHANCEMENT
Authors: YANG SU-HUI  , ZHANG HAN-ZHUANG  , GUO XIU-ZHEN  , WANG DONG  , GAO JIN-YUE  ,   吉林大学物理系，长春  130021
Published: November 2020

The effects of finite bandwidths of laser fields and Doppler broadening on electromagnetically induced two-photon transparency and absorption enhancement in a four-level system have been discussed in this paper.The optimum experimental arrangement of this system for reducing the Doppler effects of the three laser fields has been obtained by the calculation results.
EFFECTS OF SELF-ION IRRADIATION ON SECONDARY DEFECTS IN MeV P+-IMPLANTED Si
Authors: TIAN REN-HE  , ZHANG XIAO-JI  , WU YU-GUANG  , ZHANG HUI-XING  ,   北京师范大学低能核物理研究所，射线束与材料工程开放实验室，北京  100875
Published: November 2020

By using plan-view and cross-sectional transmission electron microscopies and Rutherford backscattering and channeling spectroscopy technologies, the secondary defect in MeV P+-implanted Si and the effect of self-ion irradiation on them have been investigated. The experimental results showed that the depths of secondary defect peaks are a little bit larger than the mean projected ranges measured and those computed by using program TRIM. The results also pointed out that the self-ion irradiation onto the MeV P+-implanted Si with a suitable energy and dose before annealing can reduce the secondary defect formation. But if the self-ion irradiation is applied after the annealing, the effects will be contrary. The physical reason of these has been discussed. Furthermore, the critical dose of the secondary-defect occurring in Si+- and P+-implanted Si have been presented, and the relation of the critical dose with the ion-implantation energy has been also discussed.
NEW EXPLICIT AND TRAVELLING WAVE SOLUTIONS FOR A CLASS OF NONLINEAR EVOLUTION EQUATIONS
Authors: YAN ZHEN-YA  , ZHANG HONG-QING  , FAN EN-GUI  ,   大连理工大学数学科学研究所，大连 116024
Published: November 2020

In this paper, with the help of Mathematica, three travelling wave solutions for a class of nonlinear evolution equations utt+auxx+bu+cu3=0 are obtained by trigonometric function method and Wu-eliminition method which include new trarelling wave solutions, bell soliton solutions and kink soliton solutions. Some equations such as Duffing equation, Klein-Gordon equation, Landau-Ginburg-Higgs equation and 4 equation are particular cases of the evolution equations. The method also can be applied to other nonlinear equations.
MICROSTRUCTURAL FEATURE OF NANOPHASE Sn-Bi PARTICLES PRODUCED BY AN ELECTROHYDRODYNAMIC TECHNIQUE
Authors: YU XI-FENG  , HU HUO-SHENG  , HE LI-DUAN  , JIANG ZHENG  , LIU XIANG  , HU ZHUANG-QI  ,   (1)东北大学材料与冶金学院，沈阳 110006; (2)中国科学院金属研究所快速凝固非平衡合金国家重点实验室,沈阳 110015
Published: November 2020

Sn-Bi nanometer powders were produced by an electrohydrodynamic technique. The microstructural feature of Sn-Bi nanometer powders was investigated by means of XRD, TEM and HREM. The results show that Sn-Bi nanometer powders produced are composed of tetragonal β-Sn monophase supersaturated solid solution and rhombohedral Bi monophase supersaturated solid solution. Most of the Sn-Bi nanometer powders are single crytals, only a few Sn-Bi nanometer powders are twin crystals. The particles of﹤10nm in diameter are perfect single crystals. There exist dislocations in the particles larger than 10nm in diameter. The formation mechanism of microstructure for Sn-Bi nanometer powders is analyzed.
AN ESTIMATE OF THE DIPOLE MOMENT OF PARTICLE CLUSTERS
Authors: JIANG ZE-HUI  , HE XIAO-DONG  , HAN JIE-CAI  , DU SHAN-YI  ,   (1)哈尔滨工业大学复合材料研究所,哈尔滨 150001; (2)哈尔滨工业大学应用物理系，哈尔滨 150001
Published: November 2020

When a cluster of particles is immersed in a uniform electric field, the particles are coupled to-gether due to the mutual interaction among them. This interaction causes the dipole moment of the cluster to be dependent upon the spatial arrangement and relative permittivity of the particles and up-on the cluster size. In this work, we attempt to estimate the dipole moment of finite cubic arrays of particles, in terms of that of particle chains which has been known. We assume that a chain may be replaced by a single equivalent sphere with the same dipole moment. With replacing the chain by equivalent sphere, a cluster is simplified to a planar array, and this planar array is simplified to a chain, then the dipole moment is obtained. Numerical calculations are performed. It is found that our results are acceptable.
ULTRA-SHORT PULSE PROPAGATING IN FIBONACCI QUASI-PERIODIC OPTICAL SUPER-LATTICE INFLUENCED BY GVD AND SPM
Authors: GAO YAN-XIA  , FAN DIANG-YUAN  ,   (1)深圳大学物理系，深圳 518060; (2)中国科学院上海光学精密机械研究所高功率激光物理国家实验室,上海　201800
Published: November 2020

In this paper, from the structure feature of the Fibonacci super-lattice, based on the principles of self phase modulation (SPM) and group velocity dispersion (GVD), we make use of the split step FFT method, conduct an investigation in SPM and the effects of higher order GVD to spectral devel-opment and temporal shaping of ultra-short pulses propagating in the Fibonacci super-lattice. It is shown, when the ultra-short pulses propagating in the Fibonacci super-lattice, because of SPM and GVD, the evolution of the pulse shape and development of the spectra are asymmetric. With increasing length of the super-lattice, the pulse will split into two separate sub-pulses, and the pulse spectra may also split.
THE INTERACTION CHARACTERISTICS BETWEEN SPACE CHARGE AND DIPOLE IN THE HOST-GUEST NLO POLYMER ELECTRET DR1/PMMA FILMS
Authors: CHEN GANG-JIN  , XIA ZHONG-FU  , ZHANG YE-WEN  ,   同济大学波耳固体物理研究所，上海　200092
Published: November 2020

In this papet the interaction characteristics between space charge and dipole in the host-guest nonlinear optical polymer electret DR1/PMMA films are studied by means of the open-circuit thermal stimulate discharge(TSD) technique and measurements of the isothermal surface potential decay and the electro-optical effect. The results indicate that there are two kinds of charges：space and dipole in the poled material, the energy level for most of the space charge trapped by the traps of sample is higher than the bound level of dipole charge originating from the dipole alignment after suitable heat than the bound level of dipole charge originating from the dipole alignment after suitable heat treatment, and there is a strong interaction between space charge and dipole. The decay of space charge will cause the change of charge distribution in the materials, which subsequently leads to relaxation of the dipoles. The stability of space charge trapped in the material significantly affects the life of dipole alignment for the material.
THE ELECTRICAL PROPERTY AND ITS MECHANISM OF INTERCALATION COMPOUNDS OF CuCl2
Authors: CHUAN XIU-YUN  , CHEN DAI-ZHANG  , ZHOU XUN-RUO  , JIANG JIA-JI  , LI HE-JUN  ,   (1)西北工业大学材料科学与工程学院，西安 710072; (2)中国地质大学材料科学系,北京 100083
Published: November 2020

The electrical property of 1—4 stages of intercalation compounds of CuCl2, which were synthesized with 2—3μｍ graphite powder, was measured by the four-probe method. Their conductivity was 1.5—2.2 times as that of their host material, graphite. The higher the stage, the higher the conductivity. The microanalysis of chemical compounds by the X-ray energy spectrum scanning analysis of TEM testified that the atom ratio of chlorine and cupric was non-stoichoimetric. The vacancy of the chlorine anion the GICs increased the concentration of the carrier particle. They link up in c-axis, and enlarged the activity space of the carrier particle. The exchange of the electrovalence of the cupric ion has been testified by XPS-ESCA. Graphite and chloride in the stage structure, seem to be the conductor and insulator, which form the “sandwich” structure. This special structure produced a weak chemical bond belt and provided the carrier space in the perpendicular direction to the c-axis. These factors in and vertical to the direction of c-axis together increased the electrical properties.
EPITAXIAL GROWTH OF La0.5Sr0.5CoO3 THIN FILMS AND ITS MECHANISMS
Authors: LI MEI-YA  , WANG ZHONG-LIE  , XIONG GUANG-CHENG  , FAN SHOU-SHAN  , ZHAO QING-TAI  , LIN KUI-XUN  ,   (1)北京大学微电子研究所，北京  100871; (2)北京大学物理系，北京  100871; (3)清华大学物理系，北京  100084; (4)汕头大学科学院材料研究所，汕头  515063; (5)汕头大学科学院材料研究所，汕头  515063；北京大学物理系，北京  100871
Published: November 2020

The structures and the epitaxial growth behavior of the La0.5Sr0.5CoO3 thin films prepared by pulsed laser deposition on various substrates and at different deposition temperatures have been studied systematically.Epitaxial growth of the LSCO thin films with low resistivity and metallic conducting features has been demonstrated on the substrates of LaAlO3,SrTiO3 and MgO.Studies reveal that for the epitaxial growth of LSCO thin films,700—800℃ are the optimal deposition temperatures and LaAlO3 is the optimal substrate.Emphases are laid on the discussions of the influences and the mechanisms of substrates and deposition temperatures on the epitaxial growth of the LSCO thin films.
PERTURBATION THEORY AND EXPERIMENTAL STUDIES ON ANISOTROPY OF ORGANIC MOLECULAR FILMS
Authors: WANG WEN-JUN  , XU JIAN-HUA  , LU XIANG-ZE  , WANG GONG-MING  , WANG WEN-CHENG  ,   复旦大学物理系，上海 200433
Published: November 2020

The optical anisotropy of organic molecular films induced by molecular reorientation was investi-gated by using the perturbation method.We presented theoretical formulae about the dependence of second harmonic generation (SHG) intensity on the polarization of fundamental beam.SHG beam and the dipping direc tion.The experimental studies and discussion were given under some special conditions.The expermental results agreed well with the theoretical calculation.
A W-SHAPED POTENTIAL TRAP WITH AXIAL SYMMETRY FOR A RING-SHAPED BOSE-EINSTEIN CONDENSATE
Authors: WANG DE-ZHONG  , LU XING-HUA  , HUANG HU  , LI SHI-QUN  ,   清华大学现代应用物理系，北京 100084
Published: November 2020

A W-shaped magneto-optical potential trap with axial symmetry is proposed. The Bose-Einstein condensate confined in the trap is ring-shaped. The ground state wave functions for two extreme cases, the noninteraction and strong repulsive limits, are calculated. The critical temperature is analyzed.
EFFECT OF MEDIUM-ENERGY RADIATION ON C60 FILMS
Authors: YAO JIANG-HONG  , XU JING-JUN  , ZHANG GUANG-YIN  , ZOU YUN-JUAN  , CHEN GUANG-HUA  , YANG RU  , JIN YONG-FAN  ,   (1)北京工业大学应用物理系,北京　100022; (2)南开大学物理系,天津 300071; (3)中国科学院近代物理研究所,兰州 730000
Published: November 2020

C60 films were irradiatied ar room temperature by medium-energy(120—360 keV) radiation of different ions (H+, He+, N+, Ar+), and the radiation effects were investigated using Raman spectra. The results showed that the radiation of medium-energy ions could cause C60 films polymerized and amorphous. However, occurrence of the phenomena depends on dosage, which is related to the interaction between the radiation ion and C60 molecule. A possible explanation for the experimental results is given and the mechanism of the interaction between the radiation ion and C60 molecule is discussed.
GROUND STATE, POLARON AND BIPOLARON EXCITATIONS AND THEIR STABILITY IN PPV
Authors: LIU DE-SHENG  , ZHAO JUN-QING  , WEI JIAN-HUA  , XIE SHI-JIE  , MEI LIANG-MO  ,   山东大学物理系,济南　250100
Published: November 2020

A tight-binding model for conducting polymer poly(phenylene vinylene) (PPV) has been suggested in the framework of one-dimensional chains. The calculations showed that this model is effective to describe the ground state, polaron and bipolaron excitations in PPV. The stability of polarons and bipolarons was discussed by considering the effect of the dimensions, e-ph and e-e interactions.
DEFECTS IN GaN EPILAYERS
Authors: KANG JUN-YONG  , HUANG QI-SHENG  , T.OGAWA  ,   (1)厦门大学物理系，厦门　361005; (2)学习院大学理学部，东京都171，日本
Published: November 2020

The intensity distribution of a yellow luminescence band was observed by cathodoluminescence (CL) on GaN epilayers with different surface morphologies grown by metallorganic vapor phase epitaxy, which showed that the hexagonal hillock surface morphology had an effect on CL image of the yellow luminescence band. The polished epilayers were further investigated by CL image, atomic number contrast, and wavelength dispersive X-ray spectrometry, and were observed that the intensity of the yellow luminescence band was relatively strong around the defects associated microscope exhibited the structures of the defects different from that of GaN matrix, misfit edge dislocations and cracks. The results suggest that the defects may result from the precipitations in the V-shape grooves of imperfect coalescence during epitaxy.
COUPLED SQUEEZED LANDAU STATES
Authors: TIAN XU  , HUANG XIANG-YOU  ,   (1)北京大学物理系,北京 100871; (2)武汉汽车工业大学基础课部,武汉 430070
Published: November 2020

Coupled squeezed states for the Landau system (planar charged particle moving in a uniform magnetic field) are built. These coupled squeezed states and decoupled squeezed Landau states give some information about the circular motion of charged particles respectively.
LATTICE BOLTZMANN MODEL FOR COMPRESSIBLE FLOW SIMULATION
Authors: YU HUI-DAN  , ZHAO KAI-HUA  ,   (1)北京大学物理系北京大学非线性科学中心,北京 100871; (2)北京大学物理系北京大学非线性科学中心,北京 100871；浙江师范大学物理系,金华 321004
Published: November 2020

We present a Lattice Boltzmann model to simulate compressible flows by introducing an attractive potential based on the simple selectable sound speed model. The corresponding macro-dynamical equation from Chapman-Enskog expansion shows that this model has the advantage to soften sound speed effectively and then the Mach number is raised greatly(up to more than 3). Simulations of March cone and the comparison between theoretical expectations and simulations demonstrate that the scheme is effective in simulation of compressible flows with high Mach numbers, which would open many new applications.
INFLUENCE OF COVERAGE ON NUCLEATION AND GROWTH OF THIN FILMS
Authors: SHAO QING-YI  , FANG RONG-CHUAN  , LIAO YUAN  , HAN SI-JIN  ,   中国科学技术大学物理系,合肥 230026
Published: November 2020

In nucleation process of thin film growth, stable clusters will gradually cover substrate surface. The growth will occur in the covered parts of substrate, and the nucleation will proceed in the uncovered parts. In this paper, we investigate the influence of coverage on nucleation and growth of thin films and give a series of revised formulae for the widely used theory of thin film growth. We get that the nucleation rate is proportional to the square of uncovered area. It looks rough that the nucleation rate is considered to be a constant in thin film theories.
THE NUCLEATION THERMODYNAMICS OF DOT STRUCTURE GROWTH IN THE GROOVE STRUCTURE
Authors: YANG GUO-WEI  , ZHU JING-MEI  ,   (1)山东工业大学数理系,济南 250061; (2)湘潭大学物理系,湘潭411105；清华大学材料科学技术系,北京 100084
Published: November 2020

The nucleation thermodynamics of dot structure in the groove structure of substrate surface by vapor deposition has been studied. A growth model of dot structure by controlling the nucleation taking place in the designed microscopic structure was suggested. The Gibbs free energy of the critical nuclei formation in the groove structure was calculated, and found that the groove structure can effectively promote the nucleation. Finally, considering the groove structure trapping effect, we deduced that the growth rate of the stable atomic cluster in the groove structure is larger than that of the atomic cluster on a flat surface.
FRACTAL Ag-AGGREGATES ON SILICONE OIL SURFACES
Authors: YANG BO  , LUO MENG-BO  , TAO XIANG-MING  , FENG CHUN-MU  , YE GAO-XIANG  ,   杭州大学物理系,杭州 310028
Published: November 2020

The growth process of large fractal aggregates formed by diffusion and rotation of silver clusters on sillicone oil surfaces in investigated. Our results indicate that the silver clusters rotate randomly on the liquid substrates and the mean square angle displacement 2> and time difference Δt satisfy the generalized Einstein relation 2>=4DθΔt. The random rotation coefficient Dθ scales with the cluster size S as Dθ∝S－γθ, where γθ＝2.4±0.3. The dependence of the fractal dimension of the aggregates on the deposition rate and aggregate time is also presented.
CHARGE DENSITY WAVE INDUCED BY INTERCHAIN NEXT-NEAREST-NEIGHBORING HOPPING INTERACTION OF ELECTRONS IN ORGANIC FEROMAGNETS
Authors: TIAN JU-PING  , WANG WEI-ZHONG  , YAO KAI-LUN  ,   (1)华中理工大学物理系,武汉 430074; (2)华中理工大学物理系,武汉430074；中国高等科学技术中心世界实验室,北京 100080; (3)江汉石油学院基础科学系,荆州 434102；华中理工大学物理系,武汉 430074
Published: November 2020

Based on our interchain coupled theoretical model for quasi-one-dimensional organic ferromagnet, we took into account the nearest and the next nearest hopping interactions between neighboring chains, to study the charge density wave and the spin density wave along the main chain. The calculated results showed that the interchain coupling results in the transfers of charge density and spin density between the main chain and the side radicals of the two coupled chains.
STRUCTURAL AND OPTICAL PROPERTIES OF SELF-ASSEMBLED InAs QUANTUM DOTS GROWN ON GaAs(311) A SUBSTRATE
Authors: JIANG WEI-HONG  , XU HUAI-ZHE  , GONG QIAN  , XU BO  , WANG JI-ZHENG  , ZHOU WEI  , LIANG JI-BEN  , WANG ZHAN-GUO  ,   中国科学院半导体研究所半导体材料开放研究实验室，北京　100083
Published: November 2020

We report the structural and optical characteristics of InAs quantum dots (QDs) grown on GaAs (311)A substrates. Atomic force microscopic result shows that QDs on (311)A surface exhibit a nonconventional, faceted, arrowhead-like shapes aligned in the [233] direction. The photolumi-nescence (PL) intensity, peak position and the full width at half maxinum (FWHM) are all colsely related to the measurement temperature. The fast redshift of PL energy and monotonous decrease of linewidth with increasing temperature were observed and explained by carriers being thermally activated to the barrier produced by the wetting layer and then being retrapped and recombined in energetically lower-lying QDs states. This model explains our results well.
ANALYSIS OF IMAGE-FORMING MECHANISM FOR A NOVEL STEREO PSEUDO COLOR MICROSCOPE
Authors: CHEN GUAN-YING  , LI SHU-ZHONG  ,   西北师范大学物理系，兰州 730070
Published: November 2020

A novel stereo pseudo color real-time image-forming system of microscope is presented, and its cause is analyzed by the theory of partially coherent light. The analytic result shows that the distribution information about phase change of the input object function, under given conditions, is reflected in the output stereo pseudo color image while an incoherent light illuminates.
ASYMMETRIC BEHAVIOR OF THE POLARIZATION BEATS SIGNAL IN A FOUR-LEVEL SYSTEM
Authors: ZHANG  YAN-PENG  , TANG TIAN-TONG  , FU PAN-MING  ,   (1)西安交通大学光电子系，西安  710049; (2)中国科学院物理研究所，北京  100080
Published: November 2020

We have studied the asymmetric behavior of the polarization beats in a four-level system when the pump beams have either narrowband or broadband linewidth, we attribute this asymmetry to the shift of the zero time delay which is due to the dispersion of the optical components.
THE COLOSSAL MAGNETORESISTANCE OF (La1-yTby)2/3Sr1/3MnO3 PEROVSKITE
Authors: WU JIAN  , CAO QING-QI  , GU KUN-MING  , LI QI-LIANG  , WANG LIANG  , ZHANG HONG-CAI  , DU YOU-WEI  , ZHANG SHI-YUAN  ,   南京大学物理系，南京大学固体微结构物理国家重点实验室，南京  210093
Published: November 2020

A series of polycrystal bulk samples of (La1-yTby)2/3Sr1/3MnO3(x=0,0.05,0.15,0.20,0.25,0.33,0.4,0.5,0.6,1.0) have been prepared. Their microstructrues, magnetization M, resistance R as well as magnetoresistance (MR) have been systemically studied in the temperature range 10K≤T≤420K. The ferromagnetic transition temperature of the samples TC decrease with the increase y. For each sample, R have peak values at a temperature close to TC. The peak values of R increase rapidly with increasing y. At the sample (y=0.40), a colossal magnetoresistance up to 900% has been observed on the temperature 170K.
CHARCTERISTIC SURFACES OF THE CHARGED AXIALLY NONSTATIONARY BLACK HOLE
Authors: LV JUN-LI  , WANG YONG-JIU  ,   湖南师范大学物理系，物理研究所，长沙  410081
Published: November 2020

Three kinds of characteristic surfaces of the charged axially nonstationary black hole are studied,namely,the event horizon,the apparent horizon and the time-like limit surface-The new results are shown when mass and charge of the black hole vary-
ENTROPY OF THE DIRAC FIELD IN SCHWARZSCHILD BLACK HOLE
Authors: LUO ZHI-JIAN  , ZHU JIAN-YANG  ,   江西师范大学物理系，南昌  330027
Published: November 2020

By using of the brick-wall method,we calculate the free energy and the entropy of Dirac spinor field in Schwarzschild black hole-It shows that the entropy of Dirac field is proportional to the area of black hole horizon and the entropy of Dirac field is 7/2 times that of Klein-Gordon field-
USING PHASE SPACE COMPRESSION TO CONTROL CHAOS AND HYPERCHAOS
Authors: LUO XIAO-SHU  ,   广西师范大学物理与电子科学系，桂林  541004
Published: November 2020

A new method is used to control chaos and hyperchaos in nonlinear system by phase space compression-As examples,the Henon map and Lorenz system as well as Rossler hyperchaotic system are researched numberically- The results show that the behavior of chaos and hyperchaos in the nonlinear system can be controlled effectivelly by phase space compression and 98P high periodic stable orbits can be obtained-
LOW-TEMPERATURE RESISTANCE MINIMUM AND ITS ORIGIN IN La2/3Ca1/3Mn1-xCuxO3(x=0.15) SYSTEM
Authors: LI GUANG  , TANG PING  , SUN XIA  , JIANG YONG  , CHEN YUE  , WANG SHENG  , HUANG ZHEN  , YUAN SONG-LIU  ,   中国科学院等离子体物理研究所，合肥  230031
Published: November 2020

The temperature dependence of resistance in the La2/3Ca1/3Mn1-xCuxO3(x=0 and 0.15) system at temperatures much lower than Curie temperature has been experimentally studied. It is found that a resistance minimum obviously appears in the zero-field R-T curve of the Cu-doped sample. Such a resistance minimum disappears when a magnetic field is applied to the sample. Based on Kondo theory, a quantitative comparison between the theory and the experimental data has been presented. It is shown that the experimental observation can be well understood within the framework of Kondo theory.
COMPUTER SIMULATION OF ENERGY TRANFER PROCESS
Authors: CHEN BAO-JIU  , QIN WEI-PING  , WANG HAI-YU  , XU WU  , HUANG SHI-HUA  ,   中国科学院激发态物理开放研究实验室，长春物理研究所，长春  130021
Published: November 2020

Monte-Carlo simulation is applied to investigate energy transfer processes in luminescence. By simulating the static distribution of the Donor-Accepter transfer rates,we have got the decay of donor luminescence in static transfer model. The result coincides with that of Inokuti-Hirayama model. The influence of D—D transfer to donor luminescence decay is simulated and discussed for both the cases of independent and correlated D—D and D—A transfer rates.
SPONTANEOUS EMISSION FROM A THREE-LEVEL ATOM IN PHOTONIC CRYSTAL
Authors: YANG YA-PING  , LIN ZHI-XIN  , XIE SHUANG-YUAN  , FENG WEI-GUO  , WU XIANG  ,   (1)同济大学物理系，上海  200092; (2)中国高等科学技术中心(世界实验室)，北京  100080；同济大学物理系，上海  200092
Published: November 2020

Spontaneous emission from a three-level atom in a photonic crystal is investigated. As a result of quantum interference and photon localization, the populations in the two upper levels displays oscillatory or quasioscillatory behavior. This depends on the relative positon of the two upper levels from forbidden gap and the initial state of atom. These Properties differ from those of three-level atom in vacuum.
A THEORETICAL STUDY ON Li+(1s2)(e,2e) REACTIONS IN COPLANAR DOUBLY SYMMETRIC GEOMETRY
Authors: JIA XIANG-FU  , YANG WEI  ,   山西师范大学物理系，信息网络中心，临汾  041004
Published: November 2020

Based on the Berakdar theory,this work investigates theoretically the triply differential cross sections for electron impact ionization of Li+(1s2) at an energy of 100eV in coplanar doubly symmetric geometry,i.e.,equal energies and equal emission angles for the two electrons in the final state.Dominant ionization mechanisms are identified and the contribution of different scattering amplitudes and the major role of initial channel Coulomb field are discussed.It turns out that the cross section in doubly symmetric geometry is strongly influenced by the interference of these amplitudes and the initial channel Coulomb field.
THE ELECTRONIC STRUCTURE AND STABILITY OF M@C28 (M=Ti,Zr,Hf) ENDOHEDRAL COMPLEXES
Authors: HUANG CHUN-HUI  , LI JUN-QIAN  ,   (1)福州大学电子科学与应用物理系，福州  350002; (2)福州大学化学系，福州  350002
Published: November 2020

We have studied the electronic structure of M@C28(M=Ti,Zr,Hf) endohedral complexes with ab initio method in B3-LYP effective core potential model and density functional theory.The computations were carried out for the geometry optimizations,which determined the structure constants of atoms in ground states,and the analysis of natural bond orbital.The interaction of Ti atom and C28 cluster was very different from that of Zr (or Hf) atom and C28 cluster. It occurred on the atomic configuration,the bonding character and the distribution of electronic states etc.According to the estimation of binding energy,three complexes could exist stably,and Zr@C28 and Hf@C28 were more stable than Ti@C28.The results have been analyzed and discussed,also compared with those in the literatare.
ENERGY,STRUCTURE AND RELATED TOPOLOGICAL PROPERTY OF BERYLLIUM CLUSTERS:2≤n≤25
Authors: ZHANG WEN-XIAN  , LIU LEI  , LI YU-FEN  ,   复旦大学物理系和三束材料改性国家重点实验室，上海  200433
Published: November 2020

We investigated the energy,structure and related topological property of beryllium clusters bound by a recently developed first-principles many-body potential(Estela Blaisten-Barojas and S.N.Khanna,Phys.Rev.Lett.,61(1988),1477).A modified cluster structure optimization method based on the genetic algorithms was used to search for the global minimum of the potential.Dependence of the energy,structure and related topological property of beryllium clusters Ben(n=2—25) on cluster size was elucidated;and a systematic structure comparison of Ben with metal cluster Mn and rare-gas cluster LJn bound by long-range Morse potential and Lennard-Jones potential,respectively,was presented.Our results showed that structures of Ben,in the range of n=2—25,can be categorized as either Mn-like or LJn-like,and many-body contributions of the potential appears to play a significant role in determining the most stable structures in beryllium systems.
A NEW CONFIGURATION OF THE LASER CAVITY FOR SIMULTANEOUS DUAL WAVELENGTH Q-SWITCH PULSED Nd∶YAlO3 LASER
Authors: LIN WEN-XIONG  , SHEN HONG-YUAN  ,   中国科学院福建物质结构研究所，福州  350002
Published: November 2020

Based on the rate equations of the Q-Switch simultaneous dual wavelength laser (SDWL) of Nd∶YAlO3 (Nd∶YAP), we have developed a new configuration of the cavity by adjusting the ratio of the cavity lengths for lasers with different wavelengths according to their emission cross sections. Therefore the competition ability and the net gain for the two different wavelengths will be equal at any time and anywhere in the laser rod, and the optimal spatial and temporal overlap of the different wavelengths can be easily realized for optimal sum frequency mixing. Besides, this configuration can overcome several disadvantages of the previously used configurations, and its photon density product integral of the two different wavelengths is about one order larger than the previous ones.
STEP MAGNETIZATION AND COLOSSAL MAGNETORESIS-TANCE IN SPIN GLASS MANGANITES La0.67Ca0.33(Mn,Fe)O3
Authors: WANG ZHI-HONG  , CAI JIAN-WANG  , SHEN BAO-GEN  , ZHAO JIAN-GAO  , ZHAN WEN-SHAN  ,   中国科学院物理研究所和凝聚态物理中心，磁学国家重点实验室，北京  100080
Published: November 2020

The step magnetization is observed in spin glass manganites La0.67Ca0.33(Mn,Fe)O3, and the colossal magnetoresistance larger than 104%(ΔR/RH) is obtained near the critical field.The micro-origin of the novel step magnetism is attributed to the melting of antiferromagnetic clusters in the applied magnetic field.
AUXILIARY REFERENCE FEEDBACK CONTROL FOR CHAOTIC SYSTEMS
Authors: TANG FANG  , QIU QI  ,   北京航空航天大学理学院物理系,北京 100083
Published: November 2020

The problem of controlling conservative chaotic systems is investigated in this paper. Based on time delay feedback (TDF), a novel control method named auxiliary reference feedback (ARF) is presented. Different from TDF method, the basis to choose controlling parameters has been given. Only by appropriately adjusting feedback parameters and reference term, any periodical orbit can be reached by ARF. Numerical simulation results show that, ARF method is effective to control both dissipative and conservative systems. Moreover, we find that periodic windows controlled by ARF are stable in the presence of weak external noise.
THE ASYMPTOTIC STEADY STATE BEHAVIOR OF DETERMINISTIC GRADUAL ACCELERATION TRAFFIC FLOW MODEL
Authors: WANG LEI  , WANG BING-HONG  ,   中国科学技术大学近代物理系和非线性科学中心,合肥 230026
Published: November 2020

In this paper, the fundamental diagram of the average traffic flow speed in the asymptotic steady state as a function of vehicle density for deterministic Nagel-Schreckenberg(NS) traffic flow cellular automaton model of high speed car without stochastic delay has been studied. It is proved that due to self organization of traffic flow, the fundamental diagram in steady state of deterministic NS model is exactly the same as the of deterministic Fukui-Ishibashi(FI) traffic flow model. The result shows if the abrupt acceleration scenario(where the speed of a car may be accelerated to the velocity limit M or the maximum velocity permitted by the spacing ahead in only one time step) is changed to the gradual acceleration scenario (where the speed of a car can increase one unit at most in one time step), the traffic flow behavior in asymptotic steady state will not be changed by self organization car interactions).
PHYSICAL PROCEDURES OF THE PULSE RADIATION FROM THE DIPOLE ANTENNAS AND ITS NUMERICAL SIMULATION
Authors: WANG JUN-HONG  ,   北方交通大学光波技术研究所,北京 100044
Published: November 2020

After the discussion of the numerical simulation method based on the FDTD method and the PML technique, the motions of the charges and the electrical field lines were first employed to describe the radiation procedures of the pulse electromagnetic waves. Then the causes of how the charges are accelerated and how the motion status of the charges are maintained were further studied from the angle of interaction of charge and field. After these analyses, it was pointed out that the pulse radiation is due to the suddenly occurred time-varying electrical field (displacement current) in the open space. This view was further evidenced by two examples: one is the partly resistance loaded antenna, the other is the partly curved antenna. The radiation procedures of the pulse electromagnetic waves of many different situations were simulated throughout this paper with the contours and waveforms of electric field given. These figures are very helpful to the understanding of the radiation mechanism of the pulse electromagnetic waves.
DEPENDENCE OF RELATIVISIC HARMONIC RADIATION ON PARAMETERS OF LASER AND PLASMAS
Authors: DU CHUN-GUANG  , ZENG GUI-HUA  , XU ZHI-ZHAN  ,   中国科学院上海光学精密机械研究所强光光学开放研究实验室，上海  201800
Published: November 2020

The dependence of the relativisic harmonic radiation on the parameters of laser and plasmas is investigated.Results show that the intensity of incident laser,the length,the shape of the pulse,and the plasma density play an important role in the relativisic harmonic radiation.The results can provide scientific basis for experiments.
DIRECT PERTURBATION THEORY FOR THE KdV EQUATION
Authors: CHEN ZHI-DE  , CHEN SHI-RONG  , HUANG NIAN-NING  ,   (1)武汉大学物理系,武汉 430072; (2)武汉大学物理系,武汉 430072；广州师范学院物理系，广州 510400
Published: November 2020

An exact direct perturbation theory of the KdV equation with corrections is developed for multi-soliton case. After showing that the derivatives of the squared Jost functions with respect to x are the eigenfunctions of the linearized operator, suitable definitions of the adjoint functions and the inner product are introduced. Orthogonality relations are derved and the expansion of the unity in terms of the squared Jost functions is implied. The completeness relation of the squared Jost functions is shown by the generalized Marchenko equation. The final result indicates that in the expression of the completeness relation, the integral path is along the real axis from －∞ to ∞ but runs over near the origin, which is contrary to the Cauchy principal value appearing in previous works. This leads to the disappear once of the shelf behind the soliton due to perturbations, which was considered as a characterized effect in the previous theories.
IMPURITIES AND INTERFACE SCATTERING EFFECT ON THE DIFFERENTIAL CONDUCTANCE NORMAL METAL-d-WAVE SUPERCONDUCTOR JUNCTIONS
Authors: DONG ZHENG-CHAO  ,   淮阴师范学院物理系,淮阴 223001
Published: November 2020

Taking into account the impurities and rough interface scattering, using Bogoliubov-de Gennes (BdG) equations and Bolonedr-Tinkham-Klapwijk (BTK) model, we calculate the differential conductance of normal metal-d-wave superconductor. It is found that the tunneling spectum depends strongly on both the incident angle electrons and the crystalline axis orientation of superconductor, and exhibits the zero-bias conductance peak under suitable arrangements. Morevover, the zero-bias conductance dip can be splitted into two small conductance dips by the impurities scattering, the tunnel conductance peak at the energy gap and the zero-bias conductance are suppressed and smoothed by the interface roughnes. Our result can explain many experimental measurements on the tunneling spectum of high-Tc superconductors.