bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDY OF THE CHARACTERISTICS OF METALLIC ULTRA-FINE PARTICLES EMBEDDED IN HOST MEDIUM (I)——QUANTUM WELL DOT MODEL OF VLTRA-FINE PARTICLES
Authors: HUANG JUE-HUA  , XUE ZENG-QUAN  ,   北京大学无线电电子学系,北京100871
Published: November 2020

A quantum well dot model of ultra-fine particles (UFP) is presented in this paper. It is assumed that principal UFP characteristics are determined by non-localized electrons, which are restricted within a three-demensional potential well with finite depth (quantum well dot). Electronic characteristics are contributed by both of single-electron behavior and collective be-haviors. The electron energy spectrum is mainly determined by single-electron behavior. The model reflects the atomic properties, such as bulk work funtion, atomic radius and first ioni-zing energy value, and ignores the finer UFP structures. The approximation is proved rea-sonable. A number of useful formulae and predictions are derived. (1) The famous UFP cha-racteristics, quantum size effect and shell structures of electron energy spectrum, are derived from the quantum well dot model. (2) The UFP work function and Fermi-energy level, which is diffi-cult to be obtained by other models, are calculated. The formula that expresses the work func tion xarying with UFP size variation is derived, which explains well the experiments. The work function increases at first and then decreases gradually to bulk one with UFP size in-creasing. (3) The average energy space (AES) near Fermi- energy and the relationship bet-ween AES and electron interaction are derived. And the famous Kubo formula can be derived from quantum well dot model. (4) Finally, the model predicts the existence of electron energy subbands in UFP and semiconductor behavior of metallic UFP in some size. When particle size increases the sub-bands can not be discriminated and finally disappears, the particle shows complete bulk characteristics.
DIFFRACTION THEORY ANALYSIS OF THE OPTICAL ELEMENT ARRAYS
Authors: ZHU CHUAN-GUI  , XUE MING-QIU  , LIU DE-SEN  , GAO YING-JUN  ,   中国科学院西安光学精密机械研究所,西安710068
Published: November 2020

In the present paper, starting from the Fresnel diffraction theory, we analyzed die dif-fraction image properties of the optical element arrays(OEA) and obtained the point spread function. We also examined the composite imaging properties of the OEA, obtained the con-ditions under which an OEA can form composite images.
MEASUREMENT OF THE AMBIPOLAR DIFFUSION COEFFICIENT USING TIME-DELAYED FOUR-WAVE MIXING WITH INCOHERENT LIGHT
Authors: ZHANG XI-QING  , ZHAO JIA-LONG  , QIN WEI-PING  , DOU KAI  , HUANG SHI-HUA  ,   中国科学院长春物理研究所,长春130021
Published: November 2020

This paper reports the theoretical calculation of the ambipolar diffusion coefficient in TDFWM-IL. We have obtained the ambipolar diffuion coefficient Da= 0.3cm2/s for CdS:Cu and compared with measured results for PbS ultrafine particles.
ELECTRON-PHONON INTERACTION AND NONLINEAR OPTICAL SUSCEPTIBILITY OF POLYMER
Authors: FU RONG-TANG  , LI LIE-MING  , SUN XIN  , FU ROU-LI  ,   (1)复旦大学物理系,上海200433;中国科学技术大学结构分析开放研究实验室,合肥230026; (2)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
Published: November 2020

The third harmonic generation spectrum (THG) of trans-polyacetylene exhibits two peaks at 0.6eV and 0.9 eV respectively. None of the existing theories can give a quantitatively satis-factory interpretation. By considering properly the excitation-dependent damping, we can get the second peak at 0.9eV. The damping of excited states that we depict in this paper due to electron-phonon interaction of polymer varies with the excited states. According to this dam-ping, the theoretical results of THG agree with the observed spectrum very well.
LOW TEMPERATURE INTERNAL FRICTION PEAKS ASSOCIA-TED WITH THE INTERACTION BETWEEN DISLOCATIONS AND POINT DEFECTS
Authors: FANG QIAN-FENG  , GE TING-SUI  ,   (1)河海大学机械学院公共课部,常州213002; (2)中国科学院固体物理研究所,合肥230031
Published: November 2020

Low tempterature internal friction peaks in cold-worked Al-Mg solid solutions were sys-tematically studied. Two internal friction peaks were observed around - 70℃ (PL2 peak) and - 50℃ (PL1 peak) when measured with a frequency of about IHz. Effect of magnesium con-tent, amount and mode of cold-working, type of solute atoms, and annealing on the appearan-ce and behavior of these two peaks were examined. Conclusions were reached thai PL2 peaks is associated with the interaction of dislocations with ‘Mg atom-divacancy' pairs and PL1 peak is associated with the interaction of dislocations with ‘Mg atom-vacancy' pairs.
INVESTIGATION OF a-C:H FILMS DEPOSITED ON SILICON SOLAR CELL AS ANTIREFLECTIVE COATING
Authors: XIA YI-BEN  , AN QI-LIN  , JU JIAN-HUA  , SHI WEI-MIN  , WANG HONG  ,   上海科学技术大学材料科学系,上海201800
Published: November 2020

α-C:H films produced on various substrate materials by using radio frequency plasma vapor deposition method have been analysed by Raman spectroscopy, indicating both diamond-like and diamond phases appear in these films. After analysing the transmittance and the refractive index of the films in the visible range, we suggest that the deposited film on silicon solar cell can be used as antireflective coating. The spectrum response value of the solar cell can be improved obviously over a wide range of wavelength from 0.55 to 1.0 μm and the short-circuit cxurent(lsc) of the solar cell is increased by 38% over the uncoated ones.
ATOM SUPERPOSITION AND ELECTRON DELOCALIZATION-MOLECULAR ORBITAL THEORETICAL STUDY OF O2 ADSORPTION AND DISSOCIATION ON Pt (111)
Authors: ZHOU RU-HONG  , CAO PEI-LIN  ,   浙江大学物理系,杭州310027
Published: November 2020

Using a cluster model Pt21O2, the interaction of O2 with Pt(lll) surface has been studied by means of the atom superposition and electron delocalization-molecular orbital (ASED-MO) theory. From the total energy minimization, we found that the O2 lying-down orientations are favored over the upright orientations, and the chemisorption on bridge site with O-O axis along the bridge is the most stable. The resulting O2 bond length is 1.35?, which is consistent with the latest NEXAFS result of (1.37 ±.05)?. The charge transferred from the substrate to the O2 molecule is about 0.6e, which is mainly filled in the O2 antibonding lπg orbital. An ac-tivation barrier of 0.20eV is found in the dissociation of the π-bonded O2 on the bridge sites. The dissociated O adatoms favor the 3-fold (hcp) hollow sites with a Pt-O bond length of 1.95?. Furthermore, a detailed calculation for local density of states (LDOS) are performed to find the components and origins of UPS features. Finally, a general discussion is given for the O2 phy-sisorption on Pt(lll).
A STUDY OF ELECTRON ABSORPTION, EMISSION AND e-v ENERGY TRANSFER PROCESS OF FH(CN)- DEFECT PAIR IN KC1
Authors: TONG PEI-QING  , KONG CHUN-YANG  , CHEN LING-FU  ,   南京师范大学物理系,南京210024
Published: November 2020

A theoretical study of the properties of the ground state and excited state of FH(CN)- de-fect pair in KC1 crystal has been conducted by using the SLC extended-ion method. The resul-ts of the calculation for electronic absorption and emission are in good agreement with the ex-periments. Under the harmonic approximation, we calculate the frequencies of the (CN)- stretching vibration. It is reasonable to attribute the observed splitting into four components in Ra-man vibrational spectrum to the four inequivalent (CN)- orientations with respect to the [110] neighboring F centre. Finally, the e-v energy transfer processes has been studied, It is pointed out that during the relaxation process polarization causeed by the change in F electrcr nic state would excite the (CN)- stretching mode from m = 0 to m = l.
QUANTUM THERMAL EFFECT OF A NON-UNIFORMLY RECTILINEARLY ACCELERATING BLACK HOLE
Authors: LUO ZHI-QIANG  , ZHAO ZHENG  ,   北京师范大学物理系,北京100875
Published: November 2020

The radiative temperature of a non-uniformly rectilinearly accelerating evaporating bla-ck hole is presented. The temperature is dependent on the time, and it is not constant on the simultaneity section of the event horizon. The location of simultaneity section of the event ho-rizon depends on the time, and its shape is not spherically symmetric.
DYNAMICS OF ROTATIONALLY SYMMETRIC SINE-GORDON SOL1TONS WITH APPLLCATIONS FOR A LARGE AREA JOSEPHSON JUNCTION
Authors: WANG QIANG-HUA  , YAO XI-XIAN  ,   南京大学物理系,南京210008
Published: November 2020

The dynamics of rotationally symmetric sine Gordon solitons of large radius under poten-tial and dissipative perturbations is considered, with the help of a collective-coordinate desc-ription of the soliton and the Lagrangian variation method. The particle-like character of the soliton is emphasized The equation of motlon and in particular, the general momentum of the soliton are obtained in a canonical manner. It is possible to discuss the dynamics of the soliton even without applying the explicit form of the perturbating potential All dyna-mical regimes in the phase space are explored. Such phenomena as the soliron return effect, soliton escaping and saddle point are addressed In the presence of dissipation, the corrected equation of soliton motion is obtained from the generalized variational equation. Finally, the application of the theoretical treatment is considered for the fluxon dynamics in a circularly symmetric Josephson junction. The analytical results are examined by direct numerical simu-lations, fairly good agreements being achieved. it turns out that the presented ueaMnem provides a reliable description of the dynamics of the sol tons considered.
DOUBLE WAVE FUNCTION DESCRIPTION FOR SPACE ROTATOR SYSTEMS IN CARTESIAN COORDINATE
Authors: LIU QUAN-HUI  ,   湖南大学应用物理系,长沙410082
Published: November 2020

In this paper, a complete, so-called double wave function description for space rotator systems in Cartesian coordinate is given. The time evolution equation for every observable in the coordinate is presented. The classical mechanical time evolution equations are found as the classical limit case of the evolution equations. And the conventional quantum mechanical description is yielded in two equivalent statistical cases. Our studies show that the Cartesian coordinate offers more perfect description than the spherical polar one does.
STATISTICAL THEORY OF SC LIQUID CRYSTALS
Authors: YANG GUO-CHEN  , QIAN XIANG-ZHONG  ,   (1)河北工学院基础课部,天津300130; (2)淮南矿业学院基础课部,淮南232001
Published: November 2020

With cell model the integral equation of distribution function is obtained by minimiza-tion of the free energy function. The orienrational order parameter, the positional order pa-rameter and their coupling are defined. By a proper choice of the interaction potential, the approximate solution of the distribution function is obtained, and also for free energy. We find that SC-SA phase tdansition can be either the second order or the first. We have calcu-lated the temperature dependence of the tilt angle and of the order parameter, as well as the ent-ropy change and the heat capacity near the critical point for TBBA, TB8A and NOBA. The variation of the phase transition temperature with molecular chain length for homologous series of TBBA and 4-n-alkoxybenzylidene-4'-aminozobenzenes are also calculated. Our calculations agree satisfactorily with experimental results.
THE INFLUENCE ON THE LIGHT SQUEEZING DUE TO VIRTUAL PHOTON PRECESSES
Authors: PENG JIN-SHENG  , LI GAO-XIANG  ,   (1)华中理工大学激光技术国家重点实验室,武汉430074; (2)华中师范大学物理系,武汉430070;中国高等科学技术中心(世界实验室),北京100080
Published: November 2020

In this paper, we have examined the influence of the counter-rotating terms on the sque-ezing phenomenon of the field in the two-photon Jaynes-Cummings model by means of the non-relativestic quantum electrodynamics. We verified that the effect of the virtual photon field in-creases the squeezing. The relation between the degree of squeezing and the field frequency, the mean photon number and the atom-field coupling constant has also analyzed.
PROFILES OF H BALMER LINES EMITTING FROM A LASER-INDUCED SILANE PLASMA
Authors: LI XIAO-WEI  , FU GUANG-SHENG  , HAN LI  , ZHANG LIAN-SHUI  , Lü FU-RUN  , WANG JIN-GUO  ,   (1)河北大学物理系,保定071002; (2)河北农业大学基础部,保定071001
Published: November 2020

Profiles of Hα,Hβ and Hγ lines, cmited from a TEA CO2 laser induced silane plasma, are measured with an optical multichannel analizer (OMA Ⅲ) The experimental results show that FWHM (full width of half maximum) of the three lines increases with the main quantum number of the corresponding upper level of the transiti ons, i.e. △λ1/2(Hα)1/2(Hβ)1/2(Hγ), this suggests that the dominant broadening mechanism of the lines is Stark broadening. Fitting the measured Hα profile to theretical data of Stark broadening, two parameters of the plasma are obtained: average electron density N = 1017cm-3 and electron temperature T = 40 000 K. From time tesolved measurements of Hβ profile, a curve of electron density versus time is derived.
THEORETICAL CALCULATION FOR MODULATION TRANSFER SPECTROSCOPY
Authors: BI ZHI-YI  , DING LIANG-EN  , MA LONG-SHENG  ,   (1)华东师范大学物理系,上海200062; (2)华东师范大学物理系,上海200062;上海工业大学146信箱,上海200072
Published: November 2020

Based on density matrix equations, we studied the interaction process among phase-modula-ted beams, unmodulated beam and a cascade three-level system. Calculations of the line shape of optical heterodyne modulation transfer spectroscopy via nearly-degenerate four-wave mixing were made. The results show that the Doppler background due to the near resonance of the in-termediate level is eliminated and the signal of two-photon transition can be distinguished from saturation absorption.
INVESTIGATION OF LaAlO3 CRYSTAL STRUCTURE
Authors: YU YU-DE  , XIE SI-SHEN  , H. BOYSEN  ,   (1)Institute für Kristallo graphie und Mineralogie der Universitat München 8000 München 2 F. R. G.; (2)中国科学院物理研究所,北京100080
Published: November 2020

X-ray diffraction, neutron scattering and thermal analysis were used to determine the room temperature crystal structure of LaAlO3 and its phase transition. Two different models were calculated and compared. Tht space group of room temperature LaAlO3 is determined as R3C (a= 5.3648 ± 2?, c = 13.1113±3?). The influence of orientation of AlO6 octahedron or room temperature LaAlO3 crystal on the phase transition was studied.
BORRMANN IMAGE OF DISLOCATION IN THE CRYSTAL OF THALLIUM ACID PHTHALATE
Authors: ZHAO QING-LAN  , GUAN TIE-TANG  ,   (1)福州大学化学系,福州350002; (2)中国科学院福建物质结构研究所,福州350002
Published: November 2020

The crystal of thallium acid phthalate (TAP) is a newly developed X-rays analyzing ele-ment with higher diffraction power. The Bormann image of the spiral dislocations has been observed and studied by means of X-ray topography. It is shown that the image contrast with fine structure nearly in the core of dislocation is decreasing not only with decreasing the crystal thickness, but also with decreasing the Borrmann coefficient s so greatly as to blur or even to make the fine contrast information loss completely when the images are inversed from "white" to "black" in the contrast.
INTERFACE DIPOLES FOR (111) SEMICONDUCTOR HETERO-JUNCTIONS AND THEIR INFLUENCES ON BAND OFFSETS
Authors: XIE JIAN-JUN  , LU DONG  , ZHANG TAO  ,   (1)复旦大学物理系,上海200433; (2)河南师范大学物理系,新乡453002
Published: November 2020

The interface dipoles for (111) lattice-matched semiconductor hererojunctions are calcula-ted employing the tight binding interface-bond-polarity model. The calculated results are com-pared with that of (110) and (001) interfaces. The effects of the interface orientation and the interface composition on the interface dipoles are discussed. It is shown that the dependence of the interface dipoles on the interface orientation and the interface composition is very weak tor isovalent heterojunctions, therefore the corresponding band offsets are almost isotropic; the anion-mixed (111) interface has a negative dipole and the cation-mixed (111) interface has a po-sitive one for nonisovalent heterojunctions, their average equals to the dipole of the nonpolar (110) interface.
APPLICATION OF TIME DOMAIN METHOD IN STUDY OF FE PHASE TRANSITION
Authors: LI JING-DE  , LI JIA-BAO  , FU SHI-LIU  ,   中山大学物理系,广州510275
Published: November 2020

The concept of time domain parameter is defined. In a small temperature region of (49±1)℃, dielectric spectroscopy of the time and frequency domains of a TGS single crystal is measured was FE phase transition of the crystal occurs. The results are devided into three components contributed by polarization of lattice, motion of electric domains, and activation of screen charges respectively. The latler two components make the ratio between static die-lectric constant and dielectric constant of acoustic frequency increase from 1 to 2.5 in this tem-perature region. The loss peak is provided mainly by screen charges, and the corresponding anomaly of free relaxation time appears near 48.615℃
ANISOTROPIC DIFFRACTION IN DOPED KNSBN PHOTOREFRACTIVE CRYSTAL
Authors: BIAN SHAO-PING  , ZHANG JING-WEN  , XU KE-BIN  , JIANG QUAN-ZHONG  , CHEN HUAN-CHU  , SUN DA-LIANG  ,   (1)哈尔滨工业大学应用物理系,哈尔滨150006; (2)山东大学晶体材料研究所,济南250100
Published: November 2020

Two wave coupling equations on anisotropic diffraction in photorefractive crystal is deri-ved according to coupling wave theory. Phase gratig diffraction results of a He-Ne laser beam (λ= 632.8 nm) passing through tungsten bronze crystals KNSBN doped respectively Ca, Ce and Co are given. The anisotropic diffraction patterns of these three kinds of photorefractive crystals is formally analyzed using these coupling formulae. It is concluded that the anisotro-pic diffraction ring pattern will present in one of the two kinds of diffraction (e→o or o→e diffraction) for different (positive or negtive) unixial crystal. Theory analysis and experi-mental results agree fair by well.
TYPE V INTERMITTENCY IN NONDIFFERENTIABLE AND NONINVERTIBLE MAPS
Authors: HE DA-REN  , S. HABIP  , M. BAUER  , U. KRUEGER  , W. MARTIENSSEN  , B. CHRISTIANSEN  , WANG BING-HONG  ,   (1)Physics Laboralory,University of Copenhagen,DK-2100 Copenhagen,Denmark; (2)Physikalisches Institut der Universitat,D-6000 Frankfurt a. M. 11,Germany; (3)西北大学物理系,西安710069;中国科学技术大学结构分析开放研究实验室,合肥230026; (4)中国科学技术大学近代物理系,合肥230026
Published: November 2020

A both nondifferentiable (or discontinuous ) and noninvertible one-dimensional map can display a new type of intermittency. The mechanism of it is that a stable fixed point collides with the nondifferentiable of discontinuous point of the map and then disappears. This type of intermittency can happen in the case when the absolute eigenvalue of the linearised map near the fixed point equals any number smaller than 1 before the intermittency. Therefore, it can appear suddenly in any part between a period-doubling cascade, interrupt the cascade and lead to chaos. In the intermittent time plot after disappearence of the stable fixed point the dura-tion of the laminar phase follows a logarithmic dependence on the distance between a control parameter value and its critical number. This new scaling law is independent of the details of the map. We believe that this new type of intermittency should exist in many practical sys-tems.
A STUDY OF DEFEETS AND PHASE TRANSITION IN LaAlO3 SINGLE CRYSTAL
Authors: XU XIU-YING  , ZHANG XING-KUI  , FAN DE-PEI  , JIANG DONG-MEI  ,   南京大学物理系固体物理研究所,南京210008
Published: November 2020

In situ observation o phase transition in LaAlO3 crystal with the convergent polarized interference pattern at 20° to 800℃ was done. The experiment revealed the phase transition from rhombohedral to cubic at 560℃. The morphology of twin and its concentration, the cry-stallograpliic orientation of domain and the change of topography image of domain and inclusion near Tc have also been studied.
BEAM TEMPERATURES AND THE ENERGY BROADENING OF A RELATIVISTIC CHARGED-PARTICLE BEAM IN AXIALLY SYMMETRIC ELECTRIC- AND MAGNETIC-FIELDS
Authors: TIAN REN-HE  ,   北京师范大学低能核物理研究所,北京100875
Published: November 2020

Starting from the relativistic motion equation of a single particle,the motion constants were obtained. And then by using these motion constants a distribution function of the beam particles was constructed which satisfies the Vlasov equation. The beam temperatures and the energy broadening of a relativistic charged-particle beam in axially symmetric electric- and magnetic-fields have been calculated by using the distribution function,and the weakly and strongly relativistic approximations have also been discussed respectively.
DENSITY WINDOW FOR CURRENT DRIVE OF LOWER HYBRID WAVE ON HT-6B TOKAMAK
Authors: XIANG NONG  , YU GUO-YANG  ,   中国科学院合肥等离子体物理研究所,合肥230031
Published: November 2020

By considering the lower hybrid wave trajectory,spectrum variation and power deposition in HT-6B tokamak plasma,we calculated the currents driven with different plasma density. The results show that there exists a density window for lower hybrid wave current drive (LHCD) ,i. e ,LHCD would be achieved only within a certain range of plasma density. The ex-planation of such a density window is given and the parameters option is also discussed.
THE RELATIVISTIC ELECTRON CYCLOTRON WAVE DISPERSION RELATION IN PLASMA
Authors: WU JUN-LING  ,   中国科学院合肥等离子体物理研究所,合肥230031
Published: November 2020

The relativistic electron cyclotron wave dispersion relation has been derived analytically with the electron distribution function also a relativistic one. The singularity which is in-evitable in these problem has been calculated analytically without imposing any condition. So the formula obtained here can be directly applied to the general situation of wave propagation and absorption. It provided a convenient formula for the study of high temperature plasma electron cyclotron wave.
AN EXPERIMENTAL STUDY OF THE RELATIONSHIP BETWEEN SLABE, HALF-CYLINDER AND FOIL TARGET STRUCTURE AND ITS LASER PLASMA PARAMETERS DISTRIBUTION
Authors: HAN SHEN-SHENG  , XU ZHI-ZHAN  , JIANG ZHI-MING  , LI YUE-LIN  , WANG XIAO-FANG  , QIAN AI-DI  , SUN LAN  ,   中国科学院上海精密光学机械研究所,上海201800
Published: November 2020

In the paper, we present the experimental results about the relationship between the plasma parameters' distribution and its target structure. The diagnostic results show that the characteristics of electron temperature and electron density distributions depend strongly on the target structure. The ionization state distributions of different targets are also discussed and compared with the theoretical calculated results for a simple model.
THE IRAV MODES AROUND CHARGED-SOLITON IN DOPED POLYACETYLENE
Authors: XIE SHI-JIE  , MEI LIANG-MO  , SUN GUO-CHANG  ,   山东大学物理系,济南250100
Published: November 2020

With a local potential of site-impurity in the frame work of the SSH model, the Coulomb effect of the dopant ions on the vibrational modes around the charged-soliton in doped poly-acetylene has been studied. The calculated results showed that the Goldstone theorem will be destroyed and the translation mode g1 will be pined by the dopant potential. At the same time, a new even-parity mode g′ 1 has been found. The appearance of g1 and g′1 interpret well the broad peak at 930 cm-1. In addition, other localized modes have also been discussed.
INTERACTION BETWEEN TRANSITION METAL (TM) IONS AND LIGAND IONS IN TM: ZnSe CLUSTERS
Authors: HUANG MEI-CHUN  , LI YAN-LAN  , HE XIAO-GUANG  ,   (1)厦门大学物理系,厦门361005; (2)厦门大学物理系,厦门361005;美国西北大学
Published: November 2020

A new approach for studying the electronic properties of the Ⅱ-Ⅵ compounds is presented , in which the atoms in a cluster is divided into the inner ones and boundary ones, the influence of the charge transfer on the environmental potential produced by the ion lattices outside the cluster is taken into account. The occupation number of the cluster molecular orbitals is calculated by a modified DV-SCC method with a new environmental potential. The net charges and the charge transfer of the clusters TM: ZnSe are investigated from the calculated electronic structure parameters. Some of new regularity, the behaviour and concept, due to the interaction between the transition-metal ions and ligand ions are discussed in brief.
DEEP LEVEL STUDIES OF P-HEMT STRUCTURE GROWN BY MBE
Authors: LU LI-WU  , ZHOU JIE  , LIANG JI-BEN  , KONG MEI-YING  ,   (1)半导体超晶格国家重点实验室中国科学院半导体研究所,北京100083; (2)中国科学院半导体材料科学实验室,北京100083; (3)中国科学院半导体研究所,北京100083
Published: November 2020

The deep levels of P-HEMT structure grown by MBE have been studied using DLTS technique. DLTS Spectra of samples show that high temperature electron traps, having larger capture cross sections and concentrations, are measured in n-AlGaAs layer of P-HEMT structure. These traps may correlate strongly with oxygen content of n-AIGaAs layer and be responsible for electrical parameters of P-HEMT structure. The experimental results also show that DLTS technique may be a tool of optimisation design of practical devices.
OPTICAL PROPERTIES OF COHERENTLY STRAINED ALLOYS GexSi1-x ON Si (001) SUBSTRATES
Authors: XU ZHI-ZHONG  ,   复旦大学物理系,上海200433
Published: November 2020

The optical constants were calculated for coherently strained alloys GexSi1-x on Si (001) substrates with tight - binding method. The effects of strains on the electronic energy band structures are taken into account by modifying the tight-binding parameters according to the variations of the bond angle cosines and the bond lengths. For the changes of the bond lengths, an empirical scaling rule is used, in which the scaling indexes are determined through fitting the calculated values of deformation potential constants to their experimental values for Ge and Si. The momentum matrix elements in the formula for calculating the imaginary part of dielectric constants are determined by fitting the ε2 of Ge and Si. The calculated results for the optical constants , including the imaginary part of dielectric constant, the refractive index, the absorptance and the reflectance, are given both for the strained alloys and bulk alloys GexSi1-x as x=0.2 and 1. By comparison of them, the effects of strains on the optical constants are discussed.
STUDY OF THE TWO-DIMENSIONAL SQUARE LATTICE PERCOLATION MODEL
Authors: ZHU JIAN-YANG  ,   江西省抚州师范专科学校物理系,抚州344000
Published: November 2020

In this paper, the renormalisation group approach is used to treat the problem of percolation on a two-dimensional square lattice with ‘glost' field and next-nearst-neighbour interactions. The critical probability Pc and the critical exponents α,β,γ,ν,δ,η are obtained.
A NEW FORMALISM FOR DESCRIBING THE EVOLUTION OF DENSITY OPERATORS
Authors: LIN DONG-HAI  , WU QIN-YI  ,   (1)厦门大学化学系,厦门361005; (2)厦门大学化学系,厦门361005;中国科学院武汉物理研究所,武汉430071
Published: November 2020

A new formalism for describing the evolution of density operators was proposed. It can evaluate the evolution of density operators of strongly and weakly coupled spin systems in a u-nified way, and describe the experiments involving weak RF pluse. Some problems were explicitly treated including spin tickling, isotropic mixing in systems of two coupled nuclei (I= 1/2), dipolar evolution and strongly coupled AB and ABX spin systems.
ENERGY LEVEL NUMBER AND DISSOCIATION ENERGY OF DIATOMIC MOLECULES DESCRIBED BY THE q-DEFORMED OSCILLATOR MODEL
Authors: YANG GUANG-CAN  ,   广西师范学院物理系,南宁530001
Published: November 2020

The formula of dissociation energy and total energy level number of diatomic molecules is obtained by using the q-deformed oscillator model- It is shown that the dissociaron energy of the model is greater than the experimental value up to about 10 percent. The method is much in advance of the usual Birge-Sponer method and can be used as a new approximate method to evaluate the dissociation energy of diatomic molecules.
CHAOS AND OBSERVATION OF STRANGE ATTRACTOR IN CO2 LASER WITH TRANSVERSE MAGNETIC FIELD
Authors: HUANG YONG-LIN  , BA EN-XU  ,   南开大学现代光学研究所,天津300071
Published: November 2020

We have experimentally studied the instabilities of a homogeneously broadened single-longitudinal mode CO2 laser with transverse magnetic field. Self-pulsing and chaos have been observed by varying the magnetic field. The strange attractor of the laser system has also been obtained. A discussion is made on the mechanism of the phenomena observed.
INVESTIGATION OF LATTICE DEFORMATION OF POROUS SILICON FILMS BY X-RAY DOUBLE CRYSTAL DIFFRACTION
Authors: HE XIAN-CHANG  , WU ZI-QIN  , ZHAO TE-XIU  , Lü ZHI-HUI  , WANG XIAO-PING  , SUN GUO-XI  ,   (1)上海交通大学物理化学分析中心,上海200030; (2)中国科学技术大学基础物理中心,合肥230026; (3)中国科学技术大学物理系,合肥230026; (4)中国科学技术大学物理系,合肥230026;中国科学院半导体研究所,北京100083
Published: November 2020

An investigation on the lattice deformation of porous silicon layer was completed by means of symmetric and asymmetric X-ray double crystal diffraction. The structure change of porous layer is larger for the sample under lower current density during the anodization in hydrofluoric acid. Both the orientation offset and the lattice expansion in the direction normal as well as parallel to the surface of the matrixes have been measured. The crystal lattice of porous layer formed on the (111) silicon surface is proposed to be triangular distorted, and it gradually matches the lattice of substrate silicon after a time in the atmosphere.
EFFECT OF STRUCTURE ON IONIC CONDUCTIVITY IN THE NANOCRYSTALLINE MATERIALS CaF2 AND Ca0.75La0.25F2.25
Authors: SU FANG  , WU XI-JUN  , QIN XIAO-YING  , KIE BIN  , JI XIAO-LI  ,   (1)中国科学技术大学基础物理中心,合肥,230026; (2)中国科学技术大学基础物理中心,合肥,230026;中国科学技术大学结构分析开放研究实验室,合肥,230026; (3)中国科学院固体物理研究所,合肥,230031
Published: November 2020

Two kinds of nanocrystalline materials CaF2(grain fineness D =16nm) and Ca0.75La0.25F2.25(D = 11nm) possessing clean interfaces were prepared with the method of inert gas evaporation and pressed under ultra high vacuum, Their complex impedance spectra were meas-sured in detail in the temperature range of 31℃ to 530℃. The results show that (1) In the range of 300℃ to 530℃, both of the two kinds of nanocrystalline ionic solids obey the Arrhe-nius equation well; (2) Ionic conductivity of nano-CaF2 is about one order of magnitude higher than that of polycrystalline CaF2, two order of magnitude higher than that of monocrystalline CaF2, activation energy for ionic conduction, E=1.14eV; (3) Ionic conductivity of nano-Ca0.75La0.25F2.25 is 1(300℃)-0.6(525℃) order of magnitude higher than that of nano-CaF2, activation energy E is 1.00eV, somewhat lower than that of nano-CaF2, (4) When the temperature rises from 250℃ to 525℃ , the resistance of grains drops about one order of magnitude, but the resistance of interfaces descends monotonously over four order of magnetude. It is demostrated that migration of F- depends on diffusion among grains at temperature lower than 400℃, and also upon diffusion among interfaces at temperature higher than 450℃. To decrease grain fineness of materials to nanometer-size as well as to mingle fluoride with higher valence can increase the ionic conductivity obviously.
MECHANISM OF Tc DEPRESSION INDUCED BY Zn SUBSTITUTION FOR Cu IN YBa2Cu3O7-y SYSTEM
Authors: ZHAO YONG  , ZUGE XIANG-BIN  , HE YE-YE  ,   (1)浙江大学物理系,杭州310027; (2)中国科学院低温技术实验中心,北京100080
Published: November 2020

The mechanism of Tc suppression induced by Zn substitution for Cu in YBa2Cu3O7-y system has been studied with respect to its electronic transport properties in normal state, superconducting critical temperature, crystal structure, oxygen stoichiometry and so forth. The results show that Zn ion acts as impurity scattering centre, leading to the increase in the resistivity as well as to the anomalous changes of the resistance-temperature relation. In addition , Zn substitution for Cu reduces the carrier concentration due to the reduction of the number of Cu other than the oxidation state in CuO planes, which precludes the band-filling and carrier-over-saturation models for explaining the mechanism of Tc suppression. Semi-quantitative results reveal that each Zn ion present a scattering cross section with a radius larger than the average Cu-O bond length of the CuO planes. This means that a non-superconducting core may appear around each Zn ion. As a result, the superconducting path in CuO plane will be destroyed gradually.as a percolation process. The percolation threshold observed experimentally is consistent with the theoretical calculation. We believe that the emergence of the normal core together with the consequent percolation is the reason why Tc is suppressed so rapidly by Zn substitution for Cu.
MONTE CARLO STUDY OF THE PHASE DIAGRAM OF ISING FERROMAGNET WITH MIXED SPINS OF S=l/2 AND S=l WITH A CRYSTAL FIELD INTERACTION ON THE HONEYCOMB LATTICE
Authors: ZHANG GUO-MING  , YANG CHUAN-ZHANG  ,   苏州大学物理系,苏州215006
Published: November 2020

The single-spin-flip Metropolis-Monte-Carlo algorithm is applied to the study of phase diagram of Ising ferromagnet with mixed spins of S = l/2 and S = 1 with a crystal field interaction on the honeycomb lattice. The phase diagram we obtained is very close to the exact solutions and better than the results of effective field theory with correlations. All these make us arrixe the conclusion that the Metropolis Monte Carlo algorithm can also be used to study the mixed-spin model.
STRUCTURE AND MAGNETIC PROPERTIES OF RAPIDLY QUENCHED (Er1-xSmx)2Fe17Cy
Authors: SHEN BAO-GEN  , KONG LIN-SHU  , CAO LEI  ,   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

We have prepared (Er1-xSmx)2Fe17Cy(x≤0.8,1.5≤y≤2.5) Compounds with a rhombo-hedral Th2Zn17- type structure by melt-spinning . These carbides are found to be stable at high temperature. The (Er1-xSmx)2Fe17Cy carbides with y = 2. 5 have unit cell volumes about 6.3% larger and Curie tewperatures about 330-360K higher than those of the 2:17 parent compounds. Room-temperature saturation magnetizations increase with increasing C content. It is found that the carbides containing Sm exhibit easy c-axis anisotropy at room temperature. The anisotropy field of (Er0.2Sm0.82Fe17C1.5 at room temperature is 8T.
CONTROLLING Au/n-Si SCHOTTKY BARRIER CONTAI-NING HYDROGEN BY ZERO BIAS ANNEALING AND REVERSE BIAS ANNEALING
Authors: YUAN MIN-HUA  , QIAO YONG-PING  , SONG HAI-ZHI  , JIN SI-XIAN  , QIN GUO-GANG  ,   (1)北京大学物理系; (2)中国科学院国际材料物理中心,北京大学物理系
Published: November 2020

Metal Au was deposited onto oriented phosphorous doped n-type epitaxial silicon. wafers, with or without plasma hydrogen treatment, to form Au/n-Si Schottky barrier (SB). The experimental results indicate: hydrogen decreases the Schottky barrier height (SBH) of Au/n-Si by 0.13eV; the SBH of Schottcky barrier containing hydrogen (SB(H)) can be controlled by zero bias annealing (ZBA) and reverse bias annealing (RBA), i.e. ZBA decreases and RBA increases the SBH of SB(H); and the controlling of SBH is reversible in at least three ZBA/RBA cycles. The increased SBH value of SB(H) after RBA is related not only to the reverse bias used in annealiug but also to the annealing temperature.
THREE KINDS OF ELECTRIC RESPONSE MECHANISM IN CERAMICS
Authors: CHEN MIN  , LI JING-DE  , LI XIANG-QIAN  , FU DE-SHENG  ,   中山大学物理系
Published: November 2020

Using the method of time domain and frequency domain dielectric spectrum, the response signals of applied field for grains, intergranuhr boundary layer, and barrier layer in a ceramics may be dissociated. So as to give the contribution of each mechanism in total resistance and total reactance of a sample. The effect of conductivity relaxation due to hopping conductance of polaron has been observed. This effect makes the impedance of the sample appear with inductance character. The properties of intergranular boundary in three kinds of typical ceramics of zinc oxide, strontium titanate, and barium titanate are compared.
THEORETICAL STUDIES ON THE VALENCE-BAND OFFSETS AT STRAINED SEMICONDUCTOR SUPERLATTICES
Authors: KE SAN-HUANG  , WANG REN-ZHI  , HUANG MEI-CHUN  ,   厦门大学物理系,中国高等科学技术中心(世界实验室)
Published: November 2020

Ab initio calculations of electronic structure for strained superlattices (SLS) （ＧａＰ）１（ＧａＡｓ）１（００１） and （ＩｎＰ）n（ＩｎＡｓ）n（００１）（ｎ＝１，３） are carried out, the valence-band maximum Ev and the average bond energy Em in each molecular layer of SLS's are investigated with the frozen shape approach. The average-bond-energy method for determining valence-band offsets at SLS's are suggestted and tested comprehensively. Based on this method, the valence-band offsets at five SLS's under three strain conditions are determined, their strain-induced effects are discussed. The results of present work show good consistency with available experimental data.
GRAIN BOUNDARY PHASES AND ANTI-DEGRADATION PROPERTIES OF ZnO-Bi2O3-Sb2O3-BaO CERAMICS
Authors: CHEN ZHI-XIONG  , HUANG ZHUO-HE  , HE AI-QIN  , SHI BIN  ,   广州师范学院物理系
Published: November 2020

Barium additive, which can resutt in a varistor character. was doped in the usual ZnO-Bi2O3-Sb2O3 varistor ceramics. It was found that a new grain boundary phase which is barium meta antimonate (BaSbA) crystal phase dissolving other trace compositions was formed besides the known Bi2O3 and Ｚｎ2．３３Ｓｂ０．６７Ｏ4 grain boundary phases. It was also found that the ＢａＳｂ2Ｏ6 phase is thermally stable and it plays an important role in improving the degradation properties of the varistor ceramics. The anti-degradation abilities of the varistor ceramics under the long duration load voltage and the surge current are both enhanced obviously when the amount of the Bi2O3, Ｚｎ2．３３Ｓｂ０．６７Ｏ4 and ＢａＳｂ2Ｏ6 grain boundary phases are in an appropriate ratio by controlling the amount of various additives. It is particularly valuable that the degradation properties of the V-I characteristics in backward direction are improved significantly.
DEVICE FOR MEASURING THE TOTAL CROSS-SECTION (TCS) OF ELECTRON SCATTERING AND THE EXPERIMENTAL ELECTRON-MOLECULAR NITROGEN TCS AT INTERMEDIATE ENERGY
Authors: XING SHI-LIN  , XU KE-ZUN  , CHEN XIANG-JUN  , YANG BING-XIN  , WANG YONG-GANG  , PANG WEN-NING  , ZHANG FANG  , SHI QI-CUN  ,   中国科学技术大学近代物理系
Published: November 2020

This paper presents a device designed for the absolute measurement of total electron-atom and electron-molecule cross section at intermediate energy. The experimental total cross sections for electron scattering from nitrogen molecular in the energy range 500-2600eV are also given.
PHASE ORBITS OF THE EQUILIBRIUM ELECTRONS IN A FREE-ELECTRON LASER WITH A REVERSED GUIDE FIELD
Authors: XU YONG  , ZHANG SHI-CHANG  ,   (1)西南交通大学应用物理系; (2)西南交通大学应用物理系,中国高等科学技术中心(世界实验室)理论物理分中心
Published: November 2020

A canonical formulation is given of the motion of the equilibrium electrons in a reversed-guide-field free-electron laser. It is found that the helical orbits of electrons are always stable. By generating Poincare surface-of-section maps, the influences of the self-fields on the phase orbits of electrons are investigated. The results show that although the current of the electron beam is high up to 6000A, the phase orbits do not become chaotic for MIT's experimental parameters. Compared with the case of a conventional positive-guidefield, our results indicate that using a reversed guide field can apparently prevent the quality of the electron beam from degeneracy.
THEORETICAL CALCULATIONS OF THE RELATION BETWEEN THE GIANT MAGNETORESISTANCE IN Fe/Cr SUPERLATTICES
Authors: WU JIAN-HUA  , LI BO-ZANG  , PU FU-CHO  , MEI LIANG-MO  ,   (1)山东大学物理系; (2)中国科学院物理研究所
Published: November 2020

Based on the phenomenological theory of Camley and Barnas and coworkers (C-B), the dependence of magnetoresistance in Fe/Cr multilayers on the applied magne-tic field is calculated. In these multilayers an antiferromagnetic coupling exists between any two adjacent Fe-layers. The applied magnetic field is either parallel or perpendicular to the layers. Good agreement of the calculated results with the experimental ones is found. The symmetry implicitly involved in the C-B theory is disclosed and is used to simplify the original C-B formalism, this leads to the closed expressions for the distribution function of conducting electrons and for magnetore-sistance.
THE BOND LENGTHS AND THEIR EFFECTS ON THE ELECTRONIC ENERGY BAND STRUCTURES IN THE GexSi1-x ALLOYS
Authors: XU ZHI-ZHONG  ,   复旦大学应用表面物理实验室
Published: November 2020

Using the empirical tight-binding method, the bond lengths and lattice constants in the GexSi1-x alloys are calculated through minimizing the total energy in zincb-lend-like crystal models, with which the GexSi1-x alloys are simulated. With the tight-binding method the electronic band structures are calculated for the models before and after the atoms relax and the calculated results are compared with that obtained in virtual crystal approximation. The calculated results are as follows: The bond lengths in the GexSi1-x alloys generally do not depend up on the alloy compo-sition and nearly equal to the bond lengths in the Ge and Si crystals respectively. This result is consistent with the experiments quite well. The relaxation of atoms has little effects on the electronic band structures for the alloys. However, the chemical composition disorder plays the most important role in determining them.
MONTE CARLO SIMULATION OF MBE GROWTH ON GaAs VICINAL SURFACE
Authors: MAO HUI-BING  , LU WEI  , MA ZHAO-HUI  , LIU XING-QUAN  , SHEN XUE-CHU  ,   中国科学院红外物理国家重点实验室
Published: November 2020

In this paper the MBE nucleation mode on vicinal GaAs(001)surface is simu-lated by Monte Carlo method. The results show that on A-surface the 2-dimension nucleation mode is dominant at 800-1000K. On B-surface the 2-dimension nucleation mode is dominant at low temperatures, but at high temperatures the step flow mode is dominant. And at both high and low temperature, there is a saturation phenomenon.
THEORY OF SUPERCONDUCTIVITY IN ALKALI-METAL-DOPED FULLERENES
Authors: YAN DA-DONG  , WANG ZHI-JIAN  , XU TIE-FENG  , LI WEN-ZHU  ,   浙江大学物理系
Published: November 2020

It is different from the case of conventional superconductors that the alkali-metal-doped fullerenes have wide-frequency-range phonon spectra whose high-and low-frequency phonon modes are, respectively, comparable to the Fermi energy EF and the zero-temperature gap △0. This property will lead to a modification to the theory of conventional strong coupling superconductivity. In this paper, by solving the Eliash-berg equations, the expressions of Tc and △0 are obtained. The results show that both the intermolecular low-frequency modes and the intramolecular highfrequency modes participate the electron-phonon interactions; Tc mainly arise from the high-frequency modes while △0's enhancement mainly arise from the low-frequency modes. So, the experimental results can be explained, especially, the large ratio of ２△0／ｋBＴc.
FLUX PINNING AND DISSIPATION IN Tl (2223) Ag-SHEATHED TAPE WITH HIGH Jc
Authors: SUN YU-PING  , ZHANG FA-PEI  , JIANG JIAN-YI  , HU AN-MING  , WANG YING-FENG  , DU JIA-JU  , ZHANG YU-HENG  , Z.Z. SHENG  ,   (1)美国阿肯色大学物理系; (2)中国科学技术大学结构分析开放研究实验室; (3)中国科学院固体物理研究所
Published: November 2020

The dependence of resistance on temperature was measured for a Tl (2223) Ag-sheathed tape with high Ｊc(Ｊc＝１．５×１０４Ａ·ｃｍ-2，７７Ｋ，０Ｔ) in an applied magnetic field range from 0 to 0.8T. The experimental results were explained in terms of the thermally activated flux creep model. The relationship between activation energy U0 and the applied magnetic field H oriented parallel to and perpendicular to the ab plane is respectively Ｕ0∥＝０．２１ H-0.3(eV) and Ｕ0⊥＝０．１5 H-0.4(eV). The unit of H is in 0.1T. The dissipation independent of a macroscopic Lorentz force for H and measuring current I lying in the same ab plane and H parallel to I was discussed.
SCALING FORMULAE OF REFLECTION COEFFICIENT FOR LIGHT IONS
Authors: LUO ZHENG-MING  , LI TAI-HUA  ,   四川大学原子核科学技术研究所
Published: November 2020

Recently, it has been found that the transport behavior of light ions possesses obvious scaling property and can be scaled by using a parameter called scaled transport cross-section. According to this important property, we present the universal fitting formulae for the particle reflection coefficient and the energy reflection coefficient. The argument of these formulae is the scaled transport cross-section. Compared with the reflection formulae, in which the reduced energy a is taken as a scaled parameter, our formulae show excellent single value corresponding relation.
THREE-BODY DYNAMICS OF LIGHT NEUTRON RICH NUCLEI 11Li,14Be AND 17B
Authors: LI CHU-LIANG  , DUAN YI-WU  , HUANG DU-ZHI  ,   (1)湖南师范大学物理系; (2)湘潭师范学院物理系
Published: November 2020

Based on the three-body model proposed by Ren and Xu[1]，an improvement on their variational wave function has been made. The structures and the interparticle correlations have been explored by inspecting the correlated densities. A direct veri-fication supporting the neutron halo structure has been found.
THE CONTROLLING PARAMETER IN A WIGGLER-PUMPED FREE-ELECTRON LASER WITH AN AXIAL-GUIDE MAGNETIC FIELD
Authors: GOU SAN-KUI  ,   兰州大学物理系
Published: November 2020

The basic equations are given for a wiggler-pumped free-electron laser with an axial-guide magnetic field. It is found that the evolution of the electron-field system is determined by a controlling parameter which contains the contributions of the electron beam, wiggler field, axial-guide magnetic field, and the initial state of the system. The collective instability is discussed and the threshold value of the controfling parameter is obtained. Farthermore, the radiation field is expressed in the cases of W＜WT and W＞WT.
INTERACTIONS BETWEEN ELECTRONS WITH WAVES IN THE FEL AND ITS GAIN ANALYSIS
Authors: ZHAO DONG-HUAN  ,   中国科学院上海光学精密机械研究所
Published: November 2020

The interaction process between electrons with electromagnetic waves in the free electron laser (FEL) is analysed and the corresponding gain expression is-derived. The result shows that it not only reflects the coherent emittanee of FEL, but also expounds the property with output saturation of lasers. The result of analysis is close to the experiment condition of FEL.
A STUDY OF THE PHYSICOCHEMICAL CHARACTER OF THE INTERACTION OF THE LIPOSOME CONTAINING OLEIC ACID OF THE LIQUID-CRYSTAL STATE AND BIOMEMBRANE
Authors: ZHANG JING  , SUN RUN-GUANG  ,   (1)陕西师范大学实验中心; (2)陕西师范大学实验中心,中国科学院理论物理研究所
Published: November 2020

The structure of the liquid crystal state of the new antiturner agent, polyphase liposome containing oleic acid, has been studied by small angle puiypnase scattering (SAXS) and 31P nuclear magnetism resomance (31P-NMR). Experimental results show that the presence of cholesterol, oleic acid, nonionic surfactant will highly affect the structure of the liquid crystal state of the PE liposome containing oleic acid. The liquid crystal state of liposome with oleic acid made from phosphoric buffer solution containing polyvinylpyrrolidone consists of both lamellar-hexagonal phase and lamellar-cubic phase. Electron-spin-resonance (ESR) experiment shows that the W/S value in the Ehrlich ascites tumor cell increases as the amount of liposome increases.
NEW FERMI-SUPERCONDUCTING STATE FOR ELECTRON-PHONON SYSTEMS
Authors: YI LIN  ,   华中理工大学物理系
Published: November 2020

Based on an extended effective electron-phonon model, considering the strong correlation interaction between electrons, the Bogoluibov approximation of electron operators is presented and an effective phonon-electron interaction is derived. It is shown that through exchange of virtual electrons, longitudinal phonons with oppo-site wave vectors can feel an effective attractive force and form phonon pairs with an electron. For an approprate phonon density, a new superconducting phonon state with the high critical temperature appears.
SPLITTING OF LO, TO MODE RAMAN SPCETRA OF SINGLE CRYSTAL KTiOPO4
Authors: LIANG WEI  , JIANG SHAO-LIN  , HUA BAO-YING  , JIANG YI-JIAN  , CHEN GANG  , ZHANG KE-CONG  , WEI MING  ,   (1)北京工业大学环境化学系; (2)北京工业大学应用物理系
Published: November 2020

The vibration spectra of single crystal KTiOPO4 was analysed using group method tnd measured in the frequency shift range of 50-1600cm-1 at room temperature. The Raman peaks of all LO, TO modes were obtained. Upon the result of LO-TO splitting, the effective charge, mode strength and static dielectric constant of polar modes of KTP single crystal were calculated.