bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDY OF THE LUMINESCENCE PROPERTIES OF Ni2+: BeAl2O4 CRYSTAL
Authors: WEN GENG-WANG  , WANG LU-YIA  , LIU SONG-HAO  , JI HAN-TIN  , JIANG ZHI-CHEN  , CHEN JUN-DE  ,   (1)湖南师范大学物理系; (2)华南师范大学物理系; (3)中国科学院安徽光学精密机械研究所
Published: December 2020

The Laser induced fluorescence spectra and excitation decay process of Ni2+ doped with chrysoberyl were studied in temperature rang of 10 K to 300 K. It was shown that the intrinsic radiative lifetime of 3T2g state is 123±7.2 μs. Mott activation energy is 1147 cm-1. Ni2+:BeAl2O4 Crystal has considerable high radiative rate and luminescence efficiency at room temperature and is a possible good candidate for making tunable laser.
BREAKDOWN CONDITION IN A TOKAMAK
Authors: YANG SHI-CAI  , WANG LONG  ,   (1)中国科学院物理研究所; (2)中国科学院物理研究所,现在地址:重庆建筑工程学院
Published: December 2020

An experiment has been conducted on CT-6B tokamak in order to study the effect of discharge conditions, such as filling gas pressure, toroidal field, stray magnetic fields and loop vvoltage, on the breakdown. It is found that the dependence of breakdown voltage on the vertical stray field is obviously different from that on the horizontal stray field. The main experimental results are discrepant from the Townsend discharge model. The distribution function of electrons during the breakdown phase has been solved by using a Monte-Carlo code and the breakdown condition deduced from the Townsend model has been revised.
STRUCTURE ANALYSIS OF Si(111)2×1 SURFACE AND THE EFFECT OF 1×1 DOMAIN WITH LOW-ENERGY ELECTRON DIFFRACTION
Authors: WU XUE-JUN  , XU GENG  , LIU HUI-ZHOU  ,   (1)复旦大学物理系; (2)中山大学物理系
Published: December 2020

One of the problems in surface physics which has not been solved for a long time is the atomic structure of reconstructed Si(lll)2×l surface. Basing upon the calculations on dynamics of low energy electron diffraction (LEED), we analysed the intensity-voltage curve in detail to test a lot of proposed models. The buckling π-chain model has been confirmed by our results. The atomic coordinates down to the sixth layer have been further modified, so that the agreement between theoritical calculation and experiment has been improved. The most salient feature of our optimum structure is a buckling of 0.44 ?. Finally, it has been shown that the existence of relaxed 1×1 domain in Si(lll)2×l surface caused a significant effect on the results. The R-factor of integral beam will be reduced considerably by taking into account the existence of relaxed 1×1 domain.
A STUDY OF THE ELECTRONIC STRUCTURE OF THE AMORPHOUS RARE EARTH ALLOY Tb-Co
Authors: LIN ZHANG-DA  , A. S. ANDREENKO  ,   (1)Department of Physics,Moscow University; (2)中国科学院物理研究所
Published: December 2020

XPS was used to study the electronic structure of the amorphous rare earth alloy TbxCo1-x. We found that there is no significant difference in the band structure of the alloy and the core level spectra of Co and Tb between the amorphous and crystalline states. This implies that the charge transfer between Tb and Co is the same in the two states. The difference in magnetic properties for these states thus can not be explained by the different amount of charge transfer in them.
NMR STUDIES OF LITHIUM BOROVANADATE GLASSES
Authors: TIAN FENG  , WU XUE-WEN  , PAN LIN-ZHANG  , WU XIAO-LING  ,   华东师范大学物理系
Published: December 2020

The structure of lithium borovanadate (Li2O-B2O3-V2O5) glasses was studied by 11B CW-NMR technique. The fractions of BO4 and BO3 units were measured and analyzed. Basing on a FDB model, the structural model of lithium borovanadate glasses was proposed.We showed that V2O5 shared Li2O with B2O3, and combined with B2O3 in the form BVO4.5. The (N4)max are approximately constant with different K. According to this experimental result, it was deduced that there is no Reedmergnerite unit in lithium borovanadate glasses. We also learnt that without Li2O, V2O5 and B2O3 could not combine directly.
INFLUENCE OF ENERGY RESOLUTION ON EXAFS
Authors: LI CHEN-XI  , LU KUN-QUAN  , ZHAO YA-QIN  ,   中国科学院物理研究所
Published: December 2020

The finite energy resolution of EXAFS spectrometer is an important effect on EXAFS measurement. It lowers the EXAFS amplitude and the decrement in smaller k is greater than that in larger k. That causes smaller coordination number and the relative mean square displacement obtained from EXAFS data. This paper proposes a method to calculate the effect of the resolution on the structural parameters extracted from EXAFS. Structural parameters of Ge and Ni, as examples, were measured and calculated with different resolutions and the results are consistent with each other. The manner of how the effect occurs is discussed and a method to correct the influence of the finite energy resolution is presented.
DIELECTRIC PROPERTIES OF POLYBIS-(p-TOLUENE SULFONATE)-2,4-HEXADIYNE-l,6-DIAL (PTS) SINGLE CRYSTAL
Authors: RUAN YAO-ZHONG  , LI LI-PING  , CHEN YOU-JUN  , HE PING-SHENG  ,   (1)中国科学技术大学物理系; (2)中国科学技术大学应用化学系
Published: December 2020

Dielectric properties of one-dimensoional polymer PTS single crystal have been measured along the chain direction in the temperature rang 77-273 K. A second-order phase transition from a high temperature nonpolar state to a low temperature polar state accompanied by an anomaly in the dielectric constant is observed at 195 K. Two peaks in the dielectric loss are found at 150 K and 100 K. The results are explained by a model which invokes three modes of side group motions.
A POSSIBLE P WAVE HEAVY-FERMION SUPERCONDUCTOR——UBe13
Authors: FENG SHI-PING  ,   北京师范大学物理系,低能核物理研究所
Published: December 2020

Applying Landau's Fermi liquid theory, we explain the superconductive critical temperature change with pressure in UBe13. The conclusion is that UBe13 is a possible P-wave superconductor. Furthermore, we find the effect of f energy levels displacement relative to Fermi energy level and s-f hybridization increase due to applying pressure are of benefit to S-wave superconductors, but not of benefit to P-wave superconductor.
THE LIFETIME MEASUREMENT OF THE 27Al(p,a)24Mg RESONANT REACTION AT ∑p = 1565 keV BY THE PLANAR BLOCKING EFFECT
Authors: JIN WEI-GUO  , ZHAO GUO-QING  , SHAO QI-YUN  , REN YUE-HUA  , WU XIANG-JIAN  , ZHOU ZHU-YING  ,   复旦大学原子核科学系
Published: December 2020

The (111) planar blocking effect is used to measure the lifetime of the 27Al(p, α)24Mg resonant reaction at Ep=1565keV and analytical methods is used to deduce the lifetime. The (111) planar blocking dip of the Ep=1183.4 keV resonance in the 27Al(p,α)24Mg reaction is also measured and compared with that calculated by theoretical calculations. The obtained lifetime τ=17.9-4.0+4.4 as is in good agreement with that obtained by the〈110〉axial blocking effect and that reported in the literature within the range of errors.
NARROW WAVE BEAM-TYPE GRAVITATIONAL RADIATION OF SPACE ARRAYS
Authors: LI FANG-YU  , TANG MENG-XI  ,   (1)中山大学物理系; (2)重庆大学应用物理系
Published: December 2020

This paper touches upon gravitational radiant power and radiant angle distribution of space rectangular lattice arrays of mass quadrupole oscillators, and gives analytic expression. The calculation show that these arrays can generate narrow gravitational radiation wave beam which has the best directional property. The travelling wave typegravitational radiation theory, developed by Seki and his colleagues, may be regarded as a specific case of the work in this paper and can be derived naturally. Under the codition of ideal ultrahigh frequency acoustic resonance and perfect travelling wave type synchronism intensification, an numerical example calculated with our method shows that energy flux density of gravitational radiation of optimum direction of space array which consists of 100 CaS crystals of 30×30×0.03 cm3 would amount to 2.84×10-1 erg/cm2·s. This result shows the potentiality of crystal space arrays exciting high-frequency gravitational radiation.
INVESTIGATION OF DIFFUSION MARKER IN THE FORMATION OF TiSi2 THIN FILMS
Authors: HU REN-YUAN  ,   北京师范大学低能核物理研究所
Published: December 2020

By means of Xe ion implantation as a diffusion marker, we have deterinined that Si is the dominant diffusion element in the formation of TiSi2 thin film. Applying the equation of Kioson and Tu with the result of our experiment, diffusion coefficients of Si and Ti in forming TiSi2 at 600℃ has been calculated.
INTERBAND OPTICAL PROPERTIES OF AN n-DIMENSIONAL SOLID AND HARMONIC OSCILLATOR MODEL THE N/2-FOLD INTEGRAL RELATIONS
Authors: HE XING-FEI  , MO DANG  ,   中山大学微电子研究所
Published: December 2020

We demonstrate that the interhand dielectric function and its k-th derivative spectrum near an n-dimensional critical point can be evaluated from the harmonic oscillator dielectric function and its k-th derivative spectrum, respectively, by using n/2-fold integration. The physical characteristics of harmonic oscillator in the interband spectra of an n-dimensional solid are exhibited by the action of n/2-fold integral operator. Relations between interband transitions and harmonic oscillator model, and between optical properties and dimensionality are discussed. In the fractional integral expressions for the interband optical responses, dimensionality n can be generated to an arbitrary continuous parameter.
FINITE CLUSTER STUDIES OF THE FQHE
Authors: XIONG XIAO-MING  , ZHOU SHI-XUN  ,   复旦大学物理系
Published: December 2020

Finite cluster system of two dimensional electron gas under a high magnetic field are investigated by numerical diagonalization of the Hamiltonian. Especially for the three Coulomb interacting electron system, the detailed study is presented. The contribution from the uniform neutralizing background is included. Method used in this paper is very simple. The numerical result of the ground state energy at 1/3 filling factor gives good approach to that of the incompressible fluid.
THE FLUX PINNING EFFECTS OF NON-IDEAL PLANE ELECTRON SCATTER CENTRE
Authors: DING SHI-YING  , YU ZHENG  , SHI KE-XIN  ,   南京大学物理系
Published: December 2020

A model of non-ideal plane of electron scatter flux pinning is proposed. The spread of △K/K are calculated under this model. Using GL free energy formula, The dependences of flux pinning force on thickness of the plane and impurity of matrix and electron scatter probability are obtained. The results agree well with experimental data qualitatively.
THE CRITICAL CURRENT OF MULTILAYER PbBi/SiO FILMS
Authors: DING SHI-YING  , YU ZHENG  , SHI KE-XIN  , YAN JIA-LIE  ,   南京大学物理系
Published: December 2020

Multilayer PbBi/SiO film samples are prepared with alternative vacuum-evaporating method. Their critical currents are measured at various temperatures and in parallel and perpendicular applied magnetic fields. A variety of characteristics of critical current are found.
SQUEEZING PHENOMENON IN THE CASCADE TWO-PHOTON PROCESS
Authors: LI XIAO-SHEN  , LIU ZHENG-DONG  , GONG CHANG-DE  ,   (1)江西师范大学物理系; (2)南京大学物理系
Published: December 2020

The Schrodinger's equation method is used to investigate the squeezing phenomenon of the electromagnetic field in the case of a three-level cascade atom interacting with single-mode cavity field. The effects of the stimulating strength and the coupling constants on the squeezing phenomenon are discussed. Furthermore, the roles played by the saturation effect and the two-photon process, and the relation between the 1st order coherence and the squeezing effects of the field are revealed.
A STUDY ON THE PROPERTIES OF SiO2 THIN FILM THERMALLY NITRIDED IN AMMONIA AND ITS INTERFACE
Authors: QI MING  , LUO JIN-SHENG  ,   西安交通大学电子工程系
Published: December 2020

The properties of thermally nitrided SiO2 thin film and its interface have been studied. It is found that the chemical composition, refractive index, electron trap parameters, surface mobility, fixed charge and interfacial state densities are dependent obviously on the annealing condition in ammonia. The mechanism of nitridation, anti-oxidation, and the effect of nitridation on interfacial characteristics are discussed.
QUANTUM THEORY OF FARADAY MAGNETO-OPTIC EFFECT IN THE PARAMAGNETIC MEDIA
Authors: LIU GONG-QIANG  , HUANG YAN-PING  ,   上海交通大学应用物理系
Published: December 2020

In some paramagnetic media, the effective field Hi which includes exchange interaction and external magnetic field, can cause the splitting of ground state energy level. In the region of the temprature T>Tc, the Curie temperature, there is certain probability distribution of electrons on two energy levels arised from ground state splitting. This induces the ground state energe level for double transition. It is proved by calculation according to this theory, there are several temperature characteristics for magneto-optical Faraday effect of the paramagnetic media. With the external magnetic field not too high, the ratio of the Verdet constant to magnetic susceptibility x is V/x = A(1+BT) in some media, or V/x = A(1 + B/T) in other media. It is also showed that both the real part θ′ and the imaginary part θ" of Faraday rotation are proportional to the effective field Hi, and with similar temperature character beyond the range of optical absorption.
THE ELIMINATION OF PUMP DEPLETION IN LASER-PLASMA BEAT-WAVE ACCELERATORS
Authors: MA JIN-XIU  , XU ZHI-ZHAN  ,   (1)中国高等科学技术中心(世界实验室)凝聚态与辐射物理分中心; (2)中国科学院上海光学精密机械研究所
Published: December 2020

The pump depletion is a severe problem which hinders the laser-plasma beat-wave accelerator concept from being practical. Starting with the weak relativistic equation of beat-wave excitation of electron plasma waves, we have derived the condition for eliminating the pump depletion in the frame moving with the light pulse for arbitrary pulse shapes. It is shown that the depletion can be eliminated by a phase jump of π at the center of the pump pulse and by the appropriate choice of initial plasma density detuning. The numerical calculation have yielded the dependence of the initial detuning on the pump intensity for square pump pulses, and have supported the methods used in this paper.
INVESTIGATION OF LASER-PRODUCED PLASMA USING MULTI-FRAME OPTICAL PROBING DIAGNOSTICS
Authors: JIANG ZHI-MING  , XU ZHI-ZHAN  , CHEN SHI-SHENG  , LIN LI-HUANG  , ZHANG WEI-QING  , QIAN AI-DI  ,   (1)中国高等科学技术中心(世界实验室)凝聚态与辐射物理分中心; (2)中国科学院上海光学精密机械研究所
Published: December 2020

In the six Nd:glass laser facility, a multi-frame optical diagnostic system with a 0.63 μm, 50 ps (FWHM) probing beam is set up. We use this system to investigate the states of la-ser-produced plasmas by means of simultaneous measurements of interferometry and shadow-graphy or Faraday rotation. Moreover, we have used five-time-frame interferometry or sha-dowgraphy and streaked shadowgraphy in our experiments. The results such as electron density profiles and their evolution, inhomogeneous plasma jet structure and self-generated magnetic field are obtained.
THEORETICAL ANALYSIS FOR THE EXPERIMENTS OF RAMAN FREE ELECTRON LASERS
Authors: ZHANG SHI-CHANG  ,   成都电讯工程学院物理系
Published: December 2020

In this paper we show that the abnormal phenomena near resonance are caused by the divergence of the electron orbits. The identification of the radiation mechanisms is also discussed.
APPEARENCE OF FRACTAL REGION IN ANNEALED a-Ge/Au BILAYER THIN FILMS
Authors: HOU JIAN-GUO  , WU ZI-QIN  ,   中国科学技术大学基础物理中心
Published: December 2020

Fractal regions in a-Ge/Au bilayer thin films after annealing at different temperatures were investigated by TEM, and fractal dimensions were calculated. For 100℃ annealing, un-cleating positions are fewer, large tenuous scale-invariant regions formed with fractal dimension of 1.785±0.01, for 200℃ annealing, uncleating positions increased rapidly, besides thic- ker fractal region with fractal dimension of 1.818±0.008, many isolated island-like regions formed. After 300℃ annealing, only two kind of island-like regions formed with very different size. The relationship between crystallization of a-Ge film, condensation of Au film and mechanism of appearence of fractal region was discussed based on structural and quantitative analyses.
COHERENT EFFECTS IN INTENSE LASER-FIELD INDUCED AUTOIONIZATION
Authors: YAO GUAN-HUA  , XU ZHI-ZHAN  ,   (1)中国高等科学技术中心(世界实验室)凝聚态和辐射物理分中心; (2)中国科学院上海光学精密机械研究所
Published: December 2020

We investigate in detail the influence of second-order ionization processes on the photo-electron spectrum etc., which has been ignored previously in the study of intense laser-field induced autoionization. It is found that, in the region of laser intensity currently discussed in literature, many physical features are altered significantly. (1) Under certain conditions, line-narrowing effect disappears. (2) The olignal photoelectron peaks are greatly reduced. (3) In agreement with the most recent experimental findings on multiphoton ionization, high-order photoelectron peaks drastically increase with increasing laser intensity, and they dominate the original peaks for sufficiently high Intensities.
GENERATION OF SQUEEZING LIGHT IN A LASER CAVITY
Authors: ZHANG WEI-PING  , TAN WEI-HAN  ,   中国科学院上海光学精密机械研究所
Published: December 2020

Generation of squeezing light depends on the nonlinear optical processes. Its intensirv is usually low owing to the limitation of the conversion efficiency. In this paper, the general condition for producing squeezing light is given. According to this condition, the conclusion is obtained that a laser cavity with a nonlinear medium and a gain medium can sime-ltaneously amplify the light intensity and reduce the quantum fluctuation of one quadrature phase component of the light field.
PIEZORESISTIVE PROPERTIES OF BORON-DOPED PECVD μc-Si FILMS
Authors: GUO SHU-WEN  , TAN SONG-SHENG  , WANG WEI-YUAN  ,   中国科学院上海冶金研究所
Published: December 2020

The piezoresistive properties of boron-doped PECVD microcrystalline Si films (μc-Si) deposited on SiO2 coated Si, covar or quartz substrates have been investigated. The relations between the gauge factor (G. F.) and doping concentrations as well as the film thickness etc, have been obtained experimentally. The maximum longitudinal G. F. of 25 and 20 are measured for Si and covar substrates respectively. An expression for calculating G. F. of p-type μc-Si is derived theoretically by using the spliring model of heavy and light hole band at k = 0 and the thermionic emission theory. The calculated dependences of G. F. on the doping concentrations, grain size and trap state density agree well with the experimental results, which offer a better understanding of the piezoresistive characteristics of μc-Si or poly-Si, and enable to optimize the design and fabrication of the μc-Si or poly-Si strain gauges.
TRANSITION METAL ATOM CHEMISORPTION ON IONIC CRYSTALS
Authors: LIU ZHEN-PENG  ,   辽宁大学物理系
Published: December 2020

A model of a transition metal adatom chemisorption on ionic crystals, which is modelled by a semi-infinite chain of alternating A-B atoms, is studied. The Anderson-News approach is adopted to take account of the Coulomb repulsion between the d-orbital electrons of the adatom. Using self-consistent Green's function method, the chemisorption energies and transfer of adatom charge are calculated for different values of the couplilng constant between d-orbital electrons of adatom and surface of ionic crystal Some interesting qualitative conclusions are obtained by discussing the existence conditions and properties of various self-consistent solutions.
DIELECTRIC, FERROELECTRIC AND PYROELECTRIC PROPERTIES OF LITHIUM SODIUM NIOBATE AT LOW TEMPERATURES
Authors: ZHONG WEI-LIE  , ZHANG PEI-LIN  , ZHAO HUAN-SUI  , CHEN HUAN-CHU  , CHEN FU-SHENG  , SONG YONG-YUAN  ,   (1)山东大学晶体材料研究所; (2)山东大学物理系
Published: December 2020

The dielectric, ferroelectric and pyroelectric properties of Li0.025Na0.975NbO3 crystals grown by the Czochralski technique have been investigated in the temperature range of 20 K to 300 K. The anomalies of the dielectric constant, electric polarization and pyroelectric properties indicate the existence of a low temperature phase transition. It occurs at about 180 K on cooling and at about 260 K on heating, wit an extraordinary large thermal hysteresis of about 80 K. The room temperature structure of the crystal has been determined and the possible point groups of the low temperature phes deduced. The time response of the pyrocle-ctric charge has been observed. A peculiar new phenomenon that the pyroelectric charge changes its polarity with time is reported. It is attributed to the coexistence of two phases in the process of phase transition.
TEMPERATURE-DEPENDENT 11B NMR STUDIES OF B2O3 GLASS
Authors: XU SHU  , PAN LIN-ZHANG  , TIAN FEN  , WU XUE-WEN  ,   华东师范大学物理系
Published: December 2020

The vitreous and liquid phase of B2O3 are investigated by the temperature-dependent 11B CW-NMR technique. The results show that there are two processes in the structure changes of B2O3 glass with temperature increasing. Above 430℃, an increasing number of bonds begin to snap off and the number of boroxol rings is reduced accordingly. Above 600℃, a chain-like structure is formed, which is composed of B2O3 bipyramids. Above 930℃, this chain-like structure is broken to give B2O3 molecules.
CHARGE TRANSFER IN SILVER SURFACE-MOLECULE SYSTEM
Authors: MIAO RUN-CAI  , PAN DUO-HAI  , ZHANG PENG-XIANG  , LI XIU-YING  ,   (1)陕西师范大学物理系激光室; (2)中国科学院物理研究所
Published: December 2020

The band of charge transfer transition was detected in optical absorbance spectra whenmolecule adsorbed on the silver surface in silver sol and silver mirror The effect of anion(Cl-) on the transition was studied. The relationship between aggregation and charge transfer was discussed and some explanations were given.
OPTICAL ABSORPTION PROPERTY OF TiO2-DOPED VYCOR GLASS
Authors: LING PING  , HUANG XI-HUAI  ,   中国科学院上海硅酸盐研究所
Published: December 2020

The structure and optical absorption property of TiO2-doped Vycor glasses are studied. The experimental results indicate that the optical absorption of the glasses are determined by anatase microcrystals in the glasses. The absorption edge shifts to long (or short) wavelength with increasing (or decreasing) of the microcrystal size. Anatase microcrystal of diameter about 80 ? shows the same absorption edge as that of bulk crystal.
THE Al-GaAs(100)(4×1) INTERFACIAL REACTION STUDIED BY HREELS, XPS AND LEED
Authors: LU XUE-KUN  ,   复旦大学表面物理实验室
Published: December 2020

In combining with X-ray photoelectron spectroscopy (XPS) measurement, the high resolution electron energy loss spectroscopy (HREELS) is used to investigate the evolution of energy gap width during the formation of Al-GaAs(l00) Interface. It is found that at room temperature, the product of Al-GaAs(100) interface reaction is AlAs. And AlGaAs alloy is formed after an annealing treatment. Low energy electron diffraction (LEED) is used also to study the deposition process of Al on GaAs(100)(4×1) surface. The deposited surface is disordered at the beginning and become ordered with Al deposition amount increasing.
NEUTRON DIFFRACTION STUDY OF Y2(Fe1-xSix)14B
Authors: YANG JI-LIAN  , DING YONG-FAN  , ZHANG BAI-SHENG  , JIN LAN  , ZHOU HUI-MING  , YE CHUN-TANG  , YANG YING-CHANG  , XING FENG  , KONG LIN-SHU  ,   (1)北京大学物理系; (2)中国原子能科学研究院
Published: December 2020

The outstanding permanent magnetic material Nd2Fe14B possesses very high energy product. But its Curie temperature is a little bit too low for practical application. Some elements were added into the material in order to raise the Curie temperature. Reference [9] and our recent experimental results show that the Curie temperature can be made higher by partiy subsituting silicon for iron in the material and in Y2Fe14B. For understanding the effect of silicon on magnetism, the occupancy of Si in Y2Fe14B was studied by neutron diffraction. The neutron diffraction results show that silicon occupies preferentially the sites of c, j1, and k2. The magnetic interaction theory is applied to explain the experimental results.
HOLE SUBBANDS AND OPTICAL TRANSITIONS OF SUPERLA- TTICES IN MAGNETIC FIELD
Authors: XIAN JIN-ZHEN  , XIA JIAN-BAI  ,   (1)清华大学物理系; (2)中国科学院半导体研究所
Published: December 2020

Hole subbands and optical transitions of superlattices in magnetic field are calculated on the basis of the Luttinger-Kohn effective mass theory. The method of calculation is described in detail, and the dependences of Landau energy levels on magnetic fields and well widths are presented. It is found that when magnetic field or well width increases the intermixing of heavy and light holes becomes obvious, only the three lowest states still keep their original characters of heavy holes. It is also found that the third light hole subband is necessary for the convergence of solutions. The magnetic-optical transition probabilities and the effective masses of cyclotron resonance are discussed.
PRESSURE BEHAVIOR OF BOUND EXCITONS IN GaAs1-xPx :N
Authors: ZHANG YONG  , YU QI  , ZHENG JIAN-SHENG  , YAN BING-ZHANG  , WU BO-XI  , LI GUO-HUA  , WANG ZHAO-PING  , HAN HE-XIANG  ,   (1)厦门大学物理学系; (2)中国科学院半导体研究所
Published: December 2020

The photoluminescence of GaAs0.15P0.85: N has been investigated under hydrostatic pressure at 77 K. The NN1 emission is clearly seen when P>10kbar. Meanwhile, luminescence quenching and band narrowing of Nx line have been observed under pressure. The results show that the pressure effectively enhances the Nx→NN1 thermally assisted exciton transfer processes. The pressure behaviors of Nx and NN1 levels have been analysed and fitted to a theoretical model. The pressure coefficients of the levels and some parameters related to their wavefunctions have been determined by fitting calculations.
A SIMPLE APPROACH FOR THE CALCULATION OF FORCE CONSTANTS OF SEMICONDUCTORS——APPLICATION TO THE STUDY OF PHONONS AT THE GaAs(111)-2×2 SURFACE
Authors: LIN ZI-JING  , WANG KE-LIN  ,   中国科学技术大学基础物理中心
Published: December 2020

An analytical expression for the force constants of semiconductors with arbitrary hybridization is derived by using the bond orbital approximation to simplify the calculation of electronic band structure energy of the system. This method is shown to be simple and effective by the comparison between the theoretical calculation and experimental results of phonon dispersion curves of several materials. Applying this method to the study of phonon at GaAs (111)-2×2 sarface, the dispersion curves of phonons that are strongly localized at the surface are obtained.
THE APPLICATION OF THE SUPERSPACE GROUP ON THE VERNIER STRUCTURES
Authors: ZHAO ZHI-BO  , MA RU-ZHANG  ,   北京科学技术大学材料物理系
Published: December 2020

The nonstoichiometric compound Ba1+xFe2S4(0.062≤x≤0.143) and the rare earth-transition rnetal tetraborides R1+εFe4B4(ε≈ 0.1, R = Ce, Pr, Nd, Sm, Gd, Tb), both composed of two interpenetrating substructures, are examples of the vernier structures. In present paper, the symmetry of the crystal structure in these two systems is characterized by the superspace group approach developed by de Wolff et al. The superspace group for Ba1+xFe2S4 compound is P1IssI4/mmm and the one for all R1+εFe4B4 compounds is P1Iss(P42/ncm). The diffraction selection rules in the commensurate models for the vernier structures, those often occur and are not related to the systematic absences of the three-dimensional space groups, are explained according to the results of the systematic absences discussed in the superspace. Such diffraction selection rules are very useful to predict where the measurable intensities can be found in the case of crystal structure analysis for the vernier structures.
EXPERIMENTAL STUDIES OF EXCITED STATES IN THE COLLISIONS OF ELECTRON WITH HELIUM AND ARGON
Authors: YU DE-HONG  , YANG FENG  , LEI ZI-MING  , PAN GUANG-YAN  , LIU JIA-RUI  ,   中国科学院物理研究所
Published: December 2020

We studied excitation processes of the targets in collisions of electron with helium and argon by optical method. Using the optical multichannel analysis system (OMA), we measured the emission spectrum of the collision systems. And the absolute emission cross sections are obtained in the electronic energy range of 200-500 eV.
LINE PROFILES OF HYDROGENIC IONS FROM HIGH-TEMPERATURE AND HIGH-DENSITY PLASMAS
Authors: HOU QING  , LI JIA-MING  ,   (1)中国高等科学技术中心(世界实验室)理论物理分中心; (2)中国科学院物理研究所
Published: December 2020

Applying the Hooper's first-order theory, we have calculated the static micro-electric field distributions and have examined the validity of the first-order theoretical calculations. The Lyman line profiles (n→1) from hydrogenic ions have been calculated. As the principle quantum number n is odd, there is no central peak and two splitted peaks exhibit for the Lyman line profile. Electron-impact broadening has negligible effects on such sepera-rions of the splitted peaks, which are suitable for plasma density diagnostics. The Lyman line proifles in the wing regions, which are formed dominantly by the static micro-electric field distributions, can also be applied for plasma density diagnostics.
LUMINESCENT PROPERTIES OF Tb3+ AND Eu3+ IN LnP5O14 CRYSTALS
Authors: ZHANG GUI-LAN  , CHEN TING  , CHEN WEN-JU  , HONG GUANG-YAN  ,   (1)南开大学物理系; (2)中国科学院长春应用化学研究所
Published: December 2020

The absorption and fluorescence spectra of Tb3+ and Eu3+ in LnP5O14 crystals at room temperture were observed. Based on absorption spectra and Judd-Ofelt theory, experimental and theoretical oscillator strengths were calculated. Series phenomenolo-gical intensity parameters were determined according to a least-square fitting. Then a calculation of the radiative transition probabilities and lifetimes of 5D3→7F5, 5D4→7F4 and 5D4→7F6 in TbP5O14, as well as 5D0→7F2 and 5D0→7F4 in EuP5O14 was carried out. We also obtain corresponding fluorescence lifetime by using time-resolved spectroscopy at various temperatures. The experimental results are in agreement with theoretical results. Our results confirmed that the lifetime of Tb3+ 5D3 depends mainly on the electric dipole-dipole cross relaxation between 5D3→5D4 and 7F6 →7F0.
A NEW METHOD OF MEASURING THE WORK FUNCTION OF MATERIALS
Authors: YANG DE-QING  , CHEN ER-GANG  ,   云南大学物理系
Published: December 2020

This paper reports a new method of measuring the work function of meterials. The method is based on accurate measuring of energy distribution of secondary electrons and contact potential difference of meterials. We call it the method of secondary electron emission-contact potential difference (SEE-CPD method). The work function of pure metals of Ni, Al, Au and Mo were measured by this method. The results are well consistent with that obtained by using photo-electron and Kelvin's method. The fundamentals and applications of the SEE-CPD method are proved to be correct and reliable.
SELF-CONSISTENT BAND STRUCTURE, ELECTRONIC PRESSURE AND SUPERCONDUCTIVITY IN HCP-WC AND MON
Authors: SHEN YAO-WEN  , HUANG MEI-CHUN  ,   厦门大学物理系
Published: December 2020

The self-consistent band structure, total and partial density of states for the stable compounds hcp-WC and MoC are calculated by the LMTO-ASA method based on Kohn-Sham's LDF theory. On the basis of theoretical parameters obtained from our ab initio calculations, the total and partial electronic pressure, the electron-ion interaction constant η, electron- ph-onon coupling constant λ and superconducting transion temperature Tc are studied. The theoretical results have been verified by both the experimental photoemission spectra and ground-state properties, as well as the superconductivity data.
THERMAL EXPANSION COEFFICIENT OF YBa2Cu3O7-x WITHORTHORHOMBIC AND TETRAGONAL PHASES
Authors: RUAN YAO-ZHONG  , LI LI-PING  , HU XUE-LONG  , PENG DING-KUN  , HU JUN-BAO  , ZHANG YU-HENG  ,   (1)中国科学技术大学材料科学系; (2)中国科学技术大学物理系
Published: December 2020

Thermal expansion coefficient of YBa2Cu3O7-x with the tetragonal and orthorhombic structural phases were measured by the method of differential parallel-plate capacitance. There exist anomalies near 205 K for orthorhombic phase and between 92 K-130 K for tetragonal phase respectively. We suggest that the former may be related to the lattice instability, indicating that there is a strong electronphonon interaction; the latter may result from the structure phase transition which destroys the high Tc superconductivity. A small jump of the thermal expansion coefficient at Tc was observed in the orthorhombic phase and from this the pressure effect was estimated.
STRUCTURE OF EXITED FRANCIUM ATOM
Authors: LIU LEI  , LI JIA-MING  ,   (1)中国高等科学技术中心(世界实验室)理论物理分中心; (2)中国科学院物理研究所
Published: December 2020

Based on atomic self-consistent-field theory (i.e., independent electron model), we have performed both nonrelativistic and relativistic calculations for the energy levels of exited Ry-dberg francium atoms. Our relativistic theoretical results agree well with recent experimental measurments. Relativistic effect of high Z atoms is also discussed. A relativistic calculation is necessary to calculate the energy levels for high Z atoms.
THE OH ABSORPTION SPECTRUM As A PROBE FOR DEFECT STRUCTURE OF LiNbO3 CRYSTAL
Authors: FENG XI-QI  , YING JI-EENG  , WANG JIN-CHANG  , LIU JIAN-CHENG  ,   中国科学院上海硅酸盐研究所
Published: December 2020

The OH- infrared absorption band in the LiNbO3 crystal with various Li/Nb ratios and MgO contents have been measured at room temperature. The structure of the absorption band of nearly stoichiometric crystals consists of three sub-bands with slightly different peak position, their relative heights change with Li/Nb ratios. The OH- absorption band in heavily Mg-doped crystal has a structure consisting of two peaks, the shift of peak position to shorter wavelength is about 54 cm-1. Basing on the crystal structure and the model of the defect structure of the LiNbO3 crystal suggested by Abrahams and Smyth (1-2), these observations are discussed for three different structures, i.e., stroichiometric, congruent and Mg-doped crystals, respectively. The shift of the peak position of the OH- absorption band in heavily Mg-doped crystal to shorter wavelength is suggested to be caused by the Mg2+ ions getting into Nb5+ sites when the Mg-doping level was higher than the threshold level in Mg-doped LiNbO3 crystals.
ORBITAL SPIN-SPLITTING FACTORS FOR CONDUCTION ELECTRONS IN LEAD: DE HAAS-VAN ALPHEN STUDIES WITH MAGNETIC FEEDBACK
Authors: REN YAN-RU  ,   北京师范大学物理系
Published: December 2020

Using the magnetic feedback technique, a detailed experimental study has been made on the spin-splitting factors gc associated with the conduction electrons in extremal orbits on the Fermi surface of lead, by measuring the relative strengths of the harmonic amplitudes of the de Haas-van Alphen waveform. Particular attention has been paid to the influence of sample inhomogeneity. Experimental gc values are given for most of the extremal orbits on the lead Fermi surface for high-symmetry directions of [100] , [110] , and [111] of the magnetic field. These gc values are found to span the range from 0.71 to 1.147. The large deviation from the free-electron value are consequences of strong spin-orbit and electron-phonon interactions.
THE STABILITY OF STRUCTURE MODELS OF Si(111) 7×7 SURFACE
Authors: LIU HUI-ZHOU  , LI ZHE-YIN  ,   中山大学物理系
Published: December 2020

In this paper, based on the concept of building blocks with interactions, we study the stability of models of Si(lll) 7×7 reconstructed surface. With use of tight-binding method, we calculated formation energies of various building blocks and their interactions. With these building blocks, various large unit surfaces can be constructed and their total energies can be easy estimated, without heavy calculations. We evaluate the surface energies of Si(lll) 5×5 and 7×7 DAS models, and get the results of -0.467 eV and -0.477 eV, respectively, close to the results of Qian and Chadi. Moreover, we point out that neither the 7×7 adatom model nor the 7×7 adatom-vacancy model are stable.
SURFACE MODE ABSORPTION AND INFRARED OPTICAL PROPERTIES OF SMALL SPHERICAL α-Fe2O3 PARTICLES
Authors: LI RUO-LIN  , LI ZENG-FA  , ZHANG CHUN-PING  , ZHANG GUANG-YIN  ,   南开大学物理系
Published: December 2020

The small spherical α-Fe2O3 particles with uniform size and regular shape were prepared by improved hydrolysis method. The infrared transmisson spectra of this two kinds of particles different in dimension were measured, and all surface modes of small spherical α-Fe2O3 particles were obtained. The effect of aggregation on absorption were discussed, and the two absorption bands in spectra were explained with the approximation of chain aggregation by cylindrical microcrystals. Surface mode theory of multi-atomic cubic particles was generalized and applied to α-Fe2O3 particles in monoaxial crystal structure. The theoretical results of surface mode frequency of α-Fe2O3 particles were presented, which agreed well with those of experiments. The existence of generalized modified LST relation was verified.
FRACTAL MODEL OF THE INTERFACE BETWEEN ELECTROLYTE AND ELECTRODE AND ITS FREQUENCY RESPONSE
Authors: YU WEN-HAI  , DING YI  ,   中国科学技术大学材料科学与工程系
Published: December 2020

A fractal model of the interface between electrolyte and electrode has been proposed. The ac frequency response of the interface is discussed. The phenomenon of the constant phase angle (CPA) impedance expressed by Zp= A(iω)-p discovered in the measurements is explained. A relation between the exponent p and the dimension D of the fractal interface p=(4-D)/2 is obtained and compared with those suggested by others previously.
THE PRESSURE DEPENDENCE OF THE EXPANSIVITY AND OF THE ANDERSON-GRüNEISEN PARAMETER IN THE GENERAL CONDITION
Authors: YAN ZU-TONG  , SUN ZHEN-HUA  ,   (1)安徽师范大学物理系; (2)中国科学院长春应用化学研究所
Published: December 2020

In this paper, the general relations between the Anderson-Grüneisen parameter and the first derivative of the bulk modulus with respect to pressure and between the bulk modulus and pressure are derived theoretically. And from these relations, we further obtain the pressure dependence of the Anderson-Grüneisen parameter and of the coefficient of thermal expansion under general conditions.
RESEARCH FOR HIGH RYDBERG STATES OF Ru
Authors: XU XIANG-YUAN  , TANG JIAN-ZHI  , LI LIANG-QUAN  , HUANG WEN  , ZHANG LIAN-FANC  , WEN KE-LING  , SHANG REN-CHENG  , ZHAO WEN-ZHENG  , CHEN DIE-YAN  ,   清华大学现代应用物理系
Published: December 2020

This paper discribes the measurements of Rydberg energy levels of Ru in 4d7(4F) ns (n=28-45) and 4d7(4F) nd (n=26-48) series by means of laser resonance excitation-electric field ionization method. The first ionization potential of Ru has been determined by nonlinear fitting program. These energy levels and relevant quantum defects have been calculated by using relativistic self-consistent field method The theoretical results are coincident with the experiments very well. Besides, the first ionization potential drawn from this papes has been compared with the existing data.
DISCUSSION ON THE SOLUTIONS IN DYSON BOSON REPRESENTATION
Authors: REN ZHONG-ZHOU  , XU GONG-OU  ,   (1)南京大学物理系; (2)南京大学物理系,兰州大学现代物理系
Published: December 2020

The solutions in Dyson boson representation are discussed in this paper. We point out that the physical essence of the solutions, including dydamical symmetry, is independent of the concrete representation. The solutions can be obtained by transforming the matrix of HD into triangular matrix. In some situations, this method is very simple.
TWO APPROACHES TO SYMMETRY REPRESENTATION OF VERNIER STRUCTURE IN R1+εFe4B4 COMPOUNDS
Authors: ZHAO ZHI-BO  , MA RU-ZHANG  ,   北京科技大学材料物理系
Published: December 2020

The crystal structures of all R1+εFe4B4 compounds are composed of two intepe-netrating tetragonal substructures. and form the Vernier structures. The symmetries of R1+εFe4B4 are characterized by two approaches, those of the space group under the commensurate model Rp(Fe4B4)q and the superspace group. The results indicate that the space gtoup symmetry can be applied to R1+εFe4B4 by constructing a long period superstructure Rp(Fe4B4)q, whose symmetries have been shown to be dependent on the parity of p and q. Space groups P42/n, Pccn, and Ccca(in a revised supercell) can cover the symmetry of Rp(Fe4B4)q for the different parity combinations of p and q, which is in agreement with the experimental results. The supersymmetry of all these compounds can be represented by an orthogonal superspace group PssiCmma. The related systematic extinctions are discussed, and the selection rules of Vernier structures, those can not be explained by three-dimensional space group, are obtained.
A GROWTH MODEL OF ORDERING DOMAIN IN FERROELE-CTRIC RELAXOR Pb(Mg,Nb)O3
Authors: WANG QIANG  , ZHANG XIAO-WEN  , GU BING-LIN  ,   (1)清华大学材料科学与工程系; (2)清华大学现代应用物理系
Published: December 2020

In the paper, we use the theory of orderdisorder transition to calculate the curves of long-range order parameter M vs composition y of B-site ions, and introduce a condition of charge balance between the area within ordering domain and one outside the domain to discuss its growth model with change of the composition y. The theoretical results are in agreement with experiment.
THE EFFECT OF GRAVITATIONAL RADIATION DAMPING ON THE VARIATION OF THE ORBITAL ELEMENTS OF BINARY SYSTEMS
Authors: LI LIN-SEN  ,   东北师范大学物理系
Published: December 2020

In this paper the effect of gravitational radiation damping on the variation of the orbital elements of binary system is studied using the method of perturbation. This effect results in both the secular and periodic variation of the semimajor axis and the eccentricity, however, the longitude of periastron exhibits no secular variation, but only periodic variation In addition, the deduced expression is applied to calculate the variation of secular and periodic terms of the orbital elements of binary system, Y cyg, PSR 1913 + 16 and PSR 2303 + 24, and the obtained results are discussed and compared with the relativistic effects.
SPATIALLY PERIODIC STRUCTURES OF A FOURTH ORDER REACTION-DIFFUSION SYSTEM WITH DIFFUSION INSTABILITY
Authors: LU QI-SHAO  ,   北京航空航天大学应用数理系
Published: December 2020

Spatially periodic structures of a parameterized fourth order reaction-diffusion system with-diffusion instability, where the diffusion term is governed by Cahn-Hillard's generalized diffusion law, are studied by means of bifurcation theory. A criterion of bifurcation for generating ipatially periodic steady states from spatially homogeneous steady states is provided through stability and singularity analysis. The second order approximation of spatially periodic steady states. is obtained by singular perturbation technique. The theoretical results in this paper are in good accord ance with numerical results in [3] .
PROJECTION MATRIX METHOD FOR SOLVING SOLITON EQUATIONS
Authors: XIAO YI  ,   华中理工大学物理系
Published: December 2020

In this paper, projection matrix method for solving soliton equations is described. Soliton transformation and breather transformation are derived. And the regularity of the solutions is proved in general.
A STUDY OF 3S-4D TWO-PHOTON RESONANCE ENHANCED UV COHERENT RADIATION IN SODIUM VAPOUR
Authors: ZHANG YU-YING  , HUANG XIAN-LING  , SUN TAO-HENG  ,   北京大学物理系
Published: December 2020

Using the two-photon resonance enhanced SHRS, FWM and OPSE processes in sodium vapour, the two sets of the UV coherent radiation in 230 nm-340 nm have been observed, and the characteristics of these UV radiation are presented and discussed.
SURFACE STATES OF GaP(111) SURFACE STUDIED BY ARUPS AND HREELS
Authors: LU XUE-KUN  , DONG GUO-SHENG  ,   复旦大学表面物理实验室
Published: December 2020

Angle resolved ultra-violet photoelectron spectroscopy( ARUPS) and high resolution electron energy loss spectroscopy (HREELS) are used to investigate the surface states of GaP (111) surf aces prepared by ion bombardment and annealing. It is found that the intrinsic occupied surface states related to P atom dangling bonds are located at 0.6 eV below the valence band maximum, while the defect induced empty surface states are located at 1.1 eV above the valence band maximum (Γ point). A 1.36 eV band bending in surface region is induced by these empty surface states.
AN ANALYSIS OF PARAMETER CONSTANCY OF LIGHT BEAM FOR MULTILENS RESONATORS
Authors: LI SHI-CHEN  , NI WEN-JUN  , YU JIAN  ,   天津大学精密仪器系
Published: December 2020

An analysis is given for multilens optical resonators. Dynamic characteristics of beam parameters for multilens resonators are analyzed. A new concept of compensating the effecus, caused by the change in thermal focal length is presented. Hence, a new type of thermal stable resonators——controlled model resonators also called soft resonators is presented.
INTRAMOLECULAR V V ENERGY TRANSFER OF FREON123 IN INTENSE IR LASER FIELD
Authors: YANG LI-SHU  , LIU ZONG-CAI  , LU SHI-PING  , XUN KE-YONG  , WANG ZHENG-MIN  ,   中国科学院安徽光学精密机械研究所,合肥,230031
Published: December 2020

Freon123 (CF3CHC12 and CF3CDC12) molecules are superexited by the intense IR laser pulse without tail from the TEA CO2 laser, reaching very high exited state. In the dissociation processes, it is shown that the C-C bonds having higher energy in Freon123 were mostly broken under certain experimental conditions, but only a few C-Cl bonds having lowest energy ruptured. The main products were C2F6, and H2C=C=CH2 and it's substitution derivatives. It is indicated by the relationship between the relative yields of productions and laser energy flux that intramolecular V-V energy transfer of Freon123 is nonrandomizational.
STATISTICAL THEORY OF DELAYED FRACTURE
Authors: XING XIU-SAN  ,   北京理工大学应用物理系,北京,100081,中国科学院国际材料物理中心,沈阳,110015
Published: December 2020

A statistical theory of delayed fracture in a wide range of stress (1》(ασ)/(Kt)》1) has been proposed. The fundamental idea is that microcrack stochastically evolves based on the atomic bond mechanism leading to fracture. The microcack evolution equation is given. The microcrack distribution function, fracture probability, reliability, the statistical distribution function of fracture strength and fracture life and their statistical average value are derived.
STUDY ON PHASE TRANSITION IN SMSC Cd1-xMnxSe UNDER HIGH PRESSURE
Authors: JIANG SHAN  , SHEN XUE-CHU  , HU JING-ZHU  ,   (1)中国科学院上海技术物理研究所红外物理开放研究实验室,上海,200083; (2)中国科学院物理研究所,北京,100080
Published: December 2020

Using diamond-anvel cell high pressure equipment, the phase transition of Cd1-xMnxSe under high pressure has been measured by optical absorption and X-ray diffraction methods, It has been found that the phase transition is irreversible. Under common pressure, Cd1-xMnxSe has wurzite structure, but it transforms to Nad structure under high pressure. When the pressure is removed, Cd1-xMnxSe becomes zinc blend structure. In addition, the relation between the pressure of phase transition and component x is also obtained.
INITIAL STAGE OF OXYGEN ADSORPTION ON GaP(111) SURFACES
Authors: XIAO HAN-YU  , LU XUE-KUN  , DONG GUO-SHENG  , DING XUN-MIN  , CHEN PING  ,   复旦大学表面物理实验室,上海,200433
Published: December 2020

A number of surface analysis techniques, including XPS, UPS and HREELS, are used to study oxygen adsorption on GaP(111) surfaces.Initial oxygen adsorption is found to be saturated at an exposure around 104L. Information concerning surface electron structure variation in this stage, such as surface band bending, chemical shifts, etc. has been obtained. It is found that this stage of oxygen adsorption is related to surface defects. Proper annealing treatment can remove the surface defects along with the adsorbed oxygen. Such oxygen adsorption followed by annealing might be a way for defect removal in surface engineering.
THE SUSCEPTIBILITY ANOMALY IN HEAVY FERMION SYSTEM
Authors: ZHANG YU-HENG  , ZHANG WEI-JIE  ,   (1)中国高等科学技术中心(世界实验室); (2)中国科学技术大学物理系,合肥,230026
Published: December 2020

One of the authors had pointed out that the heavy fermion system is a kind of Kondo system in which localized f-electrons can change with temperature. The f-electrons are bound in a narrow band near Fermi level. Using this model, the relation between the susceptibility and temperature is deduced and the susceptibility anomaly is explained in this paper. The calculated results of susceptibility for all the eight heavy fermion system coinside with the experimental data. The strong sample dependence of the susceptibility of the heavy fermion system has also been discussed.