bluuebunny/crossref_metadata_2025 huggingface dataset:
SOLITARY WAVES ON A TWO-LAYER FLUID WITH BASIC CURRENTS
Authors: YAN JIA-REN  , ZHONG JIAN-XIN  ,   湘潭大学物理系,湘潭411105
Published: November 2020

In this paper, we study the interface and surface solitary waves on a two-layer fluid with basic currents. It is found that there are two modes of solitary waves, i.e., the fast mode and rhe slow mode, they are always governed by a KdV equation. The influence of currents on solitary waves is discussed. By using the two-fluid model, the themocline in ocean is studied, the long, weak nonlinear waves in a homogeneous density fluid with shear flow are studied also.
THE SUPERCONDUCTIVITY, LATTICE PARAMETER AND THERMAL CHARACTERISTICS OF THE Yb-Ba-Cu(O, F) SYSTEM
Authors: ZHANG YU-LING  , LIANG JING-KUI  , RAO GUANG-HUI  , CHENG XIANG-RONG  , LI KE-SHENG  , LEI LING  , ZHENG DONG-NING  , XIE SI-SHEN  ,   中国科学院物理研究所
Published: November 2020

Superconductive samples with compositions of YbBa2Cu3F2xO7-x-δ (0≤x≤1) have been prepared. The variations of Tc, lattice constants and cell volume with the fluorine dose have been described. We report an experimental observation of an increase of Tc with a decrease of the oxygen content in the YbBa2Cu3F2xO7-x-δ (0 ≤x≤1). Therefore with the content of oxygen increasing, the lattice constants and cell volume of the superconducter become larger. The higher Tc, the larger is the velue of lattice constants (b-a) of the orthorhombic structure. It has been shown that the M-Cu-O or Cu-O part of the systems may have an essential role or the superconductivity.
EFFECTS OF LIGHT FEEDBACK ON CO2 LASER INSTABILITIES
Authors: ZHANG LI-GEN  , CHEN NAN-PENG  , BA EN-XU  ,   (1)河北轻化工学院; (2)南开大学现代光学研究所,天津,300071
Published: November 2020

The effects of transverse distribution of light field on CO2 laser instabilities are studied by means of light feedback. The phenomena of pulsing frequency shift and chaos in CO2 laser caused by light feedback are observed experimentally. The mechanism of laser instabilities resulting from the transverse distribution is discussed.
WINDING NUMBER BIFURCATION AND SUPERSTRUCTURE IN NONLINEAR DRIFT WAVES DRIVEN BY A TRAVELING WAVE
Authors: HE KAI-FEN  , A. SALAT  ,   (1)Max-Planck Institute of Plasma Physics,F. R. G.; (2)北京师范大学低能核物理研究所,北京,100875
Published: November 2020

In ref. [I] , numerical experiment reveals scaled superstructures In the bifurcation diagram for the damped nonlinear drift-wave driven by a traveling wave. In this paper, it is shown that the resonance between the solution of driv en-damped equation and that of the unperturbed system is the cause of winding number bifurcation and hence of the superstructure. The scaling law for the wavenumbers and frequencies calculated accordingly is in agreement with the numerical results.
EXCITATION CONDITIONS OF ION BERNSTEIN WAVE IN KT-5B TOKAMAK
Authors: LIU WAN-DONG  , WEN YI-ZHI  , WAN SHU-DE  , YU CHANG-XUAN  ,   中国科学技术大学近代物理系,合肥,230026
Published: November 2020

In this paper, the research results of the relations between the excitation stage of linear ion Bernstein wave (IBW) and the edge ion density fluctuation, the discharge parameters of tokamak and the antenna position in KT-5B tokamak are presented. The experiments show that large edge ion density fluctuation will make it difficult to excite IBW, the ranges of discharge parameters for optimally exciting IBW are consistent with those for normal operation of KT-5B tokamak. We find that for our toroidal current antenna, there may exist two ways of excitation, i.e. direct excitation and excitation through the electrostatic mode conversion process.
ABOVE-THRESHOLD IONIZATION INVOLVING PROCESSES OF AUTOIONIZATION
Authors: CHEN RONG-QING  , XU ZHI-ZHAN  , YAO GUAN-HUA  , YU WEI  ,   (1)中国高等科学技术中心(世界实验室)理论物理分中心; (2)中国科学院上海光学精密机械研究所,上海,201800
Published: November 2020

A simple model of above-threshold ionization which takes into account the processes of autoionization has been studied and the analytic solution of photoelectron spectra is presented. The effects of autoionization on abovethreshold ionization are discussed. It is shown that autoionization will make processes of above-threshold ionization more complicated and a lot of new effects will appear.
ELECTRONIC STRUCTURE AND CRYSTAL STRUCTURE IN Al3Y
Authors: XU JIAN-HUA  ,   中国科学院上海冶金研究所,上海,200050
Published: November 2020

The electronic structures of Al3Y in the three (DO19, Ll2, and DO22) phases were investigated using the allelectron total energy self-consistent LMTO method. The calculated results for total energy showed that the hexagonal DO19 phase is the most stable structure among these three phases, this is in agreement with experiment. Furthermore, it is found that the stability depends strongly upon the band filling of the bonding states and exhibits a inverse relationship with the density of states at EF.
FRACTAL TIME RANDOM WALKS AND DISPERSION TRANSPORT
Authors: WEN CHAO  , LIU FU-SUI  ,   (1)北方交通大学物理系,北京,100044; (2)北京大学物理系,北京,100871
Published: November 2020

We study continuous time random walk with the waiting time distribution having long-time tail t-α, 0 <α< 1. The fractal time behavior of the hopping event set is treated in a systematic and rigorous way. We construct a dynamic model which shows the fractal time behavior. The expertmenu of dispersion diffution in amorphous systems are well explained by our theory.
LONG RANGE CORRELATIONS FOR MICROSCOPIC STOCHA-STIC DYNAMICS IN A NONEQUILIBRIUM STEADY STATE (Ⅱ)——PROVE FOR THE CORRECTNESS OF A MICROSCOPIC STOCHASTIC DYNAMICALMODEL
Authors: LI FU-BIN  ,   淮北煤炭师范学院物理系,安徽,淮北,235000
Published: November 2020

As a particle model, we investigate a stochastic lattice gas with Kawasaki dynamics. We establish the connection with the fluctuating hydrodynamics. In the case of hard core interaction only we prove the validity of fluctuating hydrodynamics and obtain the corrections which are presumably model dependent.
A STUDY ON THE FAR INFRARED REFLECTION SPECTRA OF Hg1-xMnxTe
Authors: LU WEI  , YU ZHI-YI  , YE HONG-JUAN  , XU WEN-LAN  , MA KE-JUN  , SHEN XUE-CHU  ,   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
Published: November 2020

The far infrared reflection spectra of Hg1-xMnx Te with different composition in the temperature region of 4.2-300 K are reported. It is demonstrated that there are a gap mode as well as a local mode associated with impurity Mn in HgTe. The gap mode has a frequency of 97 cm-1. The theoretical analysis of the gap mode has been proceeded.
INVESTIGATIONS ON NONPROPAGATING GRAVITY-SURFACE TENSION SOLITON
Authors: HUANG GUO-XIANG  , YAN JIA-REN  , DAI XIAN-XI  ,   (1)复旦大学物理系,上海,200433; (2)湘潭大学物理系,湘潭,411105
Published: November 2020

In this paper, the method of multiple-scales is used to investigate the weak nonlinear self-modulation of the gravity-surface tension standing wave mode in a finite deep fluid which is filled in a rectangular resonator. The detailed analysis and calculations about the nonpropaga-ting soliton discovered by Wu et al. are made when external driving and damping of the surface wave are considered. The nonpropagating soliton theory established by Larraza, Put-terman and Miles is revised and developed. The correct second harmonic resonace condition about gravity-surface tension wave in the rectangular trough is obtained. The stabilities of propagating soliton are analyzed in detail according to σ-kd diagram. It is found, in addition to the static depth d, that the surface-tension of fluid is an important parameter which may control the formation of nonpropagating soliton. Finally, the nonlinear tuning curves of the surface wave resonator are discussed and compared with experimental results.
JOINT EFFECT OF STIMULATED FOUR PHOTON MIXING AND STIMULATED RAMAN SCATTERING IN OPTICAL FIBER
Authors: SHEN SHU-PO  ,   郑州大学物理系,郑州,450052
Published: November 2020

Six pairs of Stokes-anti-Stokes lines of stimulated four photon mixing in a multimode fiber with GeO2+P2O5 doped silica core are simultaneously recorded. A continuum band generated jointly by SFPM and stimulated Raman scattering is obtained in the spectral range 540-640 nm. On the basis of two different experiment results for 20 m and 200 m fiber, the mechanism of competition and transformation between SFPM and SRS are analyzed in some detail.
THE GROWTH CHARACTERISTICS AND SURFACE RECONS-TRUCTION OF Ge/Si (111) AND Si/Ge(111)
Authors: CHEN KE-MING  , ZHOU GUO-LIANG  , SHENG CHI  , JIANG WEI-DONG  , ZHANG XIANG-JIU  ,   (1)复旦大学表面物理实验室,上海,200433; (2)复旦大学表面物理实验室,上海,200434; (3)复旦大学表面物理实验室,上海,200435; (4)复旦大学表面物理实验室,上海,200436; (5)复旦大学表面物理实验室,上海,200437
Published: November 2020

The growth characteristics and surface reconstruction of Ge/Si(lll) and Si/Ge(lll) are studied by reflection high energy electron diffraction (RHEED) and Auger electron spectros-copy (AES). The growth modes are proposed based on the results. The stain effects on the growth characteristics, interface structure and surface reconstruction are further discussed.
HYDRODYNAMIC EQUATION FOR A SUPERCONDUCTOR
Authors: XIE XUE-GANG  , CHEN SHI-GANG  , HONG CHAO-SHENG  ,   (1)中国科学院物理研究所,北京,100080; (2)中国科学院物理研究所,中国科学院地理研究所北京,100012
Published: November 2020

Starting from the quasiparticle and phonon kinetic equations and the order parameter equation, we have obtained a hydrodynamic equation for a superconductor and theor etically verified the possibility of unusual diffusion of quasiparticles from regions with lower concentration to regions with higher concentration as well as the stabilizing term for short-wave fluctuations.
A SIMPLE APPROACH TO THE DYNAMICAL EVOLUTION OF HOT NUCLEI
Authors: LI GUO-QIANG  ,   杭州大学物理系,杭州,310028
Published: November 2020

Based on a simple energy density and with the help of lowtemperature expansion of Fermi-Dirac integrals, an analytical nuclear equation of state (EOS) P(s, ρ) is obtained. Under the assumption of adiabatic approximation, the time evolution of several hot/compressed nuclei are studied within the hydrodynamical framework. The critical condition of multifragmenta-tion is Particularly analysed.
THEORETICAL CALCULATION OF THE ROCKING CURVE FOR X-RAY DOUBLE CRYSTAL DIFFRACTION
Authors: MAI ZHEN-HONG  , HE CHU-GUANG  , CUI SHU-FAN  ,   中国科学院物理研究所,北京,100080
Published: November 2020

Using the X-ray dynamical theory, the reflection coefficients of X-ray double crystal diffraction in Bragg case were derived. The results of the rocking curves calculated for different kind of crystals and different diffractions show that the peak value and the integral intensity of rocking curve for σ polarization are higher than those for π polarization. And the full width at half maximum (FWHM) of σ polarization is wider than that of π polarization. It is pointed out that when the incident X-ray beam is a circle polarized one or/and the crystals A and B are different kind of crystals or/and the diffraction vector of A is different from that of B, the approximative expression of the FWHM of rocking curve for double crystal diffraction, 21/2∞, which was used by many authors, is invalid.
THE COLEMAN PHASE TRANSITION FOR THE DOUBLE sine-GORDON MODEL IN n+1 DIMENSIONS
Authors: WANG ZHEN-LI  , LOU SEN-YUE  ,   宁波师范学院物理系,宁波,315211
Published: November 2020

The Gaussian effective potential of the double sine-Gordon model in n + 1 dim ensions is computed. Within the Gaussian approximation, we prove that the model is trivial for n ≥ 3 and there exists a Coleman phase transition point for n cr=(n+2π(n+1)/2(α1R+α2R/4)(3-n)/2)/(Γ(1/2(3-n))(α1R+α2R/16)).
ELECTRON SPIN RESONANCE INVESTIGATION OF Eu2+ IN BaCl2
Authors: HOU BI-HUT  , SHI CHAO-SHU  , HAN SHI-YING  , XIA SHANG-DA  , LU XIAO-PU  ,   (1)南京大学固体微结构物理实验室,南京,210008; (2)中国科学技术大学物理系,合肥,230026; (3)中国科学技术大学物理系,合肥,230026;南京大学固体微结构物理实验室,南京,210008
Published: November 2020

The ESR spectra of BaCl2: Eu powder showed that Eu2+ ion substituting the ion Ba2+ is situated in a crystal field of the orthorhcmbic symmetry. By fitting the ESR experimental data to the axial symmetric spin Hamiltonian and the crystal field Hamiltonian, the spin Hamiltonian parameters were obtained. In addition, based on variation of ESR peak-hight versus doping concentration of Eu, the doping value Cs for saturated substitution of Eu2+ was found to be 0.34 mol%.
MONTE-CARLO STUDIES OF RADIATION DAMAGE INDUCED BY FUSION(I)——α-PARTICLES AT THE FIRST-WALL
Authors: HUO YU-KUN  , WU XUAN-HONG  , SHAO QI-YUN  , CHEN JIAN-XIN  , WU SHI-MING  , PAN ZHENG-YING  , GAO XING-HUA  ,   (1)复旦大学物理二系,上海,200433; (2)中国科学院等离子体物理研究所,合肥,230031
Published: November 2020

This paper investigates the spectra of fusion α-particle leaking out from the plasma boundary in a Tokamak fusion reactor, bombarding the first wall. The loss mechanisms of α-particle were studied, and the slowing down-diffusion equations describing the α-particle transport in plasma were set up. The contributions from banana-trapped particles, transit panicles and superbanana ripple trapped particles to the diffusion coefficient were included in the study. The equations were numerically solved for Tokamak reactors with typical parameters to obtain the required α-particle spectra. The physical significance of the results is discussed finally.
QUANTUM THEORY OF TWO-PHOTON LASER
Authors: WANG ZHI-CHENG  ,   兰州大学物理系,兰州,730001
Published: November 2020

Starting from the microscopic Hamiltonian of the three-level model and making use of the slowly varying amplitude approximation and the two-photon rotating wave approximation, we derive an effective Hamiltonian for the two-level two photon model under conditions where the two-photon process dominates the other radiartive processes, so that an exact relation between the three-level model and the two-level two-photon model is established. The effective Hamiltonian includes a term come from the optical Stark effect which was neglected in the conventional treatment. The coefficient of this term may have the same order of magnitude as the effective coupling constant. Based on this effective Hamiltonian, the standard method of Haken's laser theory is applied to study the threshold, the mean photon number, the self-induced frequency shift, the photon statistics and the fluctuation in steady states. Results are compared with previous ones which neglect the Strk effect.
JAHN-TELLER EFFECT AND THE STRUCTURAL PHASE TRANSITIONS IN LiNbO3 (I)
Authors: WU JIAN-BIN  , WANG ZHI-CHENG  ,   (1)上海交通大学应用物理系,上海,200030; (2)浙江大学物理系,杭州,310027
Published: November 2020

Starting from the Jahn-Teller-like effect, we studied theoretically the problem of structu-ral phase transition of LiNbO3 at 75℃. The results are qualitatively consistent with experimental data.
SUPERCONDUCTIVITY AND CARRIER CONCENTRATION OF SINGLE PHASE (Bi,Pb)2Sr2Ca2Cu3Oy SAMPLES
Authors: CHENG XIANO-AI  , HE ZHFN-HUI  , WANG SHUN-XI  , SHA JIAN  , CHEN XIAN-HUI  , ZHANG QI-RUI  , SUN YU-PING  , YIN HUA-QING  , DU JIA-JU  ,   (1)浙江大学物理系,杭州,310027; (2)中国科学技术大学物理系,合肥,230026; (3)中国科学技术大学应用化学系; (4)中国科学院固体物理研究所,合肥,230031
Published: November 2020

Single phase (Bi, Pb)2Sr2Ca2Cu3Oy samples have been prepared with different heat treatments. X-ray diffraction, the dependence of resistance on temperature, ac. susceptibility and Hall coefficient have been investigated. We find that all samples are of 2223 single phase, the midpoint superconducting transition temperatures (Tc) are above 100K, and Tc increases mo-notonically with the carrier concentration (nH). The experimental results show that the conditions of heat treatment affect the phase structure, Tc and nH for the Bisystem. We propose that Tc and nH. of the Bi-system are closely related to oxygen content, local composition and structure perfection.
THE FORMATION AND THE MAGNETIC PROPERTY OF Fe, Co AND Ni FINE METAL PARTICLES
Authors: LI HUA  , GONG WEI  ,   中国科学院物理研究所,北京,100080
Published: November 2020

Fine particles of Fe, Co and Ni with average diameters from 120? to 800? were prepared by a gas evaporation method in the atmosphere of argon or nitrogen. We revealed that homogeneous nucleation growth was the dominant growth mechenism of the particles prepared at low pressure (<3 Torr). The zigzag chains could be explained by the magnetic connection of particles when each particld had a multi- domain structure, and the straight chains when each particle had a single domain. The X-ray diffraction revealed that the crystal structure of Fe and Ni fine particles was the same as the bulk materials and the crystal strcuture of Co fine particles with average diameter from 200? to 300? was f.c.c. which differed from h.c.p.of bulk cobalt at room temperature. When the diameter of the particles was about 210?, 200? and 320?, which is nearly the single domain size of Fe. Co and Ni particles, the maximum corecivity of Fe, Co, Ni fine particles was 1000 Oe, 1500 Oe and 450 Oe at room temperature respectively. The saturation magnetization decreased with the decrease ef panicle size due to the increase of the volume percent of the oxide layers and the numbers of the superparamag-netic particles. A noneollinear configuration of the magnetic moments existed in oxide surface layers for fine particles.
STUDIES ON DEALUMINIZATION PROCESS OF FAUJASITE BY MONTE-CARLO METHOD
Authors: JIN QING-HUA  , SUN PING-CHUAN  , WANG JING-ZHONG  , LI ZI-YUAN  , DING DA-TONG  ,   南开大学物理系,天津,300071
Published: November 2020

In principle, four rypes of aluminum ions on the faujasite framework may be distinguished according to the next neighbour number (0,1,2,3) of aluminum appearing around their environment. The hydrogen ions associated with type-O aluminum ions are to be identified as "strong" acid, and those associated with types 1,2 and 3, as "weak" acid. In a dealuminization process, the "weak acid" aluminum ions (types 1,2 and 3) are removed preferably over the "strong acid" type-O. Based on first-order kinetics, the concentrations of all the four types aluminum ions upon dealuminization can be described in terms of the Monte-Carlo simulation of the dealuminization process of the faujasite. We conclude that the concentration of the strong acid center in dealuminization faujasites come up to its maximum around Si/Al 6.68. We also conclude that the more difference between dissolving rate constants for "strong" and "weak" aluminum ions the denser strong acid in dealuminization faujasite could be expected.
q-ROTATING OSCILLATOR MODEL (I)——q-Oscillator and Vibrational Spectra of Diatomic Molecules
Authors: YAN HONG  , CHANG ZHE  , GUO HAN-YING  ,   (1)中国高等科学技术中心(世界实验室); (2)中国科学院理论物理研究所,北京,100080
Published: November 2020

We suggest a model of q-deformed rotating oscillator which possesses the symmetry of quantum group and point out that this model can be used to describe the vibrational and rotational structures of many microscopic systems. We construct the representation of q-oscilla or algebra and give energy values of q-oscillaor in this representation. It is shown that the q-oscillator spectra can be used to describe infrared spectra, Raman spectra and vibrational structure of electronic transitions of diatomic molecules.
CRYSTALLIZATION FEATURE AND M?SSBAUER EFFECT OF Fe20Al80 AMORPHOUS POWDERS
Authors: WANG GEN-MIAO  , ZHANG DAO-YUAN  , WANG WEI-HUA  , DONG YUAN-DA  ,   (1)中国科学技术大学结构分析开放研究实验室,合肥,230026; (2)中国科学技术大学物理系; (3)中国科学院固体物理研究所,合肥,230031
Published: November 2020

Fe20Al80 amorphous powders were prepared by ball milling through 180 hours. X-ray diffraction and transmission electron microscope experiments indicate the powder sample is amorphous and also show the average particle size and crystallization products. The paramagne-tism and crystallinity of amorphous material are determined by M?ssbauer effect measurements.
ELECTRON PARAMAGNETIC RESONANCE IN GEM QUALITY ZIRCON
Authors: HAN SHI-YING  , XU YUN-XIA  , WANG FU-QUAN  ,   (1)南京大学材料分析中心,南京,210008; (2)中国地质博物馆,北京,100034
Published: November 2020

The electron paramagnetic resonance spectra of the natural single crystal of the tetragonal structure zircon containing impurity Gd3+ have been measured. The fine structure parameters were calculated using a least-squares fitting procedure. The hyperfine structure for odd isotopes 155Gd and 157Gd was clearly resolved, and the values of the hyperfine coupling constant to first order were given.
STUDY OF THE TWO-DIMENSIONAL NEXT-NEAREST-NEIG-HBOUR PERCOLATION MODEL
Authors: QU SHAO-HUA  , YAO KAI-LUN  , YU BO-MING  ,   (1)华中理工大学物理系,武汉,430074; (2)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

In this paper, we use the renormalisation group approach and Monte-Carlo simulation to treat the problem of percolation on a two-dimensional square lattice with next-nearest-neighbour interactions. The critical probability pc and the critical exponents α,β,γ and so forth are obtained. It is shown that the two-dimensional percolation problem with next-nearest-neighbour interactions belongs to different universality class from that only with nearest-neighbour interactions.
CO AND O CHEMISORPTION ON DISORDERED BINARY ALLOY NiCu
Authors: YANG ZONG-XIAN  , ZHANG TAO  ,   河南师范大学物理系,新乡,453002
Published: November 2020

One-dimensional tight-binding model and the one-electron chemisorption theory are used to calculate the chemisorption energy of CO or O on NixCu1-x surface under the average T-matrix approximation. It is found that the chemisorption of CO and O on NixCu1-x are strengthened with the increase of bulk Ni concentration. The Cu segragation to the NiCu alloy surface may weaken the chemisorption.
PHASE TRANSFORMATION AND SUPERCONDUCTIVITY OF 110K SUPERCONDUCTOR IN (Bi, Pb)-Sr-Ca-Cu-O SYSTEM
Authors: CHEN XIAN-HUI  , CHEN ZU-YAO  , QIAN YI-TAI  , GU ZHEN-TIAN  , CHENG XIANG-AI  , SHA JIAN  , WANG KE-QIN  , ZHANG QI-RUI  ,   (1)中国科学技术大学物理系,合肥,230026; (2)中国科学技术大学应用化学系,合肥,230026
Published: November 2020

High-quality single phase polycrystalline sample of 110K superconductor (Bi,Pb)2Sr2Ca2Cu3Oy was prepared, the temperature of zero resistance of which is 107K. In this paper, the formation and transformation of the 2201, 2212 and 2223 phase, and the influence of quenching temperature are discussed. The measurement of complex susceptibility shows the strength of Josephson coupling among the superconducting grains depends on the process of sample preparation. The specific heat jump is △c(107K) =5.3J/molK, and the Sommerfeld cntant is γ = 34.6mJ/molK. The specific heat jump is related to the heat treatment of samples strongly. The eletron diffraction analysis and measurement of the oxygen content of these samples are made. The relationship between the oxygen content and the superconducting volume fraction is also discussed.
SOLID ANGULAR DEFICIT AND REPULSIVE GRAVITATIONAL FIELD
Authors: SHI XIN  , LI XIN-ZHOU  ,   华东理论物理研究所,上海,200237
Published: November 2020

A global monopole produces a repulsive gravitational field outside the core in addition to a solid angular deficit, rather than an attractive gravitational field suggested in previous literatures. The global monopole-antimonopole annihilation mechanism and the geodesies are also studied.
BINOMIAL STATES OF THE TWO-LEVEL ATOMIC SYSTEM
Authors: HUANG HONG-BIN  ,   东南大学物理系,南京,210018
Published: November 2020

In this paper, we introduce the binomial state of a two-level atomic system, which is a state that yields a binomial probability distribution. Its generation, squeezing, antibunching, and subpoisson statistics are discussed. It reduces to the Glauber coherent state in certain limit, and in that limit, the binomial distribution reduces to the Poisson distribution. This limiting process destroys all nonclassical effects of the system. The Bloch vector model is used to discuss the quantum characters of mixed state of one atom. Finally, the binomial state of the atomic system and the binomial state of the Bose system is compared. It is shown that the binomial state of a Bose system can not be produced in a atomic system.
INFLUENCE OF THE INCIDENCE ANGLE OF THE ION-BOMBARDMENT ON THE SPUTTERING PARAMETERS
Authors: SHAO QI-YUN  , HUO YU-KUN  , CHEN JIAN-XIN  , WU SHI-MING  , PAN ZHENG-YING  ,   复旦大学物理二系,上海,200433
Published: November 2020

In this paper, the effects of the incidence angle of the ion-bombardment on the puttering parameters ire investigated by using Monte Carlo simulation based on the binary collision approximation. The dependence of sputtering yields, energy and angular distribution as well as threshold energy of sputtered particles on incidence angle are discussed. The results of calculation are compared with data given by semi-empirical formula and measurments.
MOMENTUM TRANSFER BETWEEN 3He QUASIPARTICLES AND THE SOLID SURFACE VIA VORTICES
Authors: Wang Cheng-tai  , Yu Lu  ,   (1)国际理论物理中心,的里雅斯特,意大利中国科学院理论物理研究所,北京,100080; (2)清华大学现代应用物理系,北京,100084
Published: November 2020

In this paper, a model of 3He liquid layer on an oscillating substrate with a thin super-fluid 4He film as a boundary layer is considered. The complex surface impedance is calculated using the transmission line theory. The slip boundary condition and the vortex motion are taken into account to compute the momentum exchange between 3He and the solid surface. The calculated values are compared with experiments.
X-RAY PHOTOELECTRON SPECTROSCOPY STUDY ON THE HOLE STATES IN YBa2Cu3O7 SUPERCONDUCTOR
Authors: Wang Nan-lin  , Tan Ming-qiu  , Zhao Zhan-chun  , Wang Jing-song  , Sha Jian  , Liu Xian-ming  , Ji Ming-rong  , Zhang Qi-rui  ,   (1)浙江大学物理系,杭州,310027; (2)中国科学技术大学结构分析开放研究实验室,合肥,230026; (3)中国科学技术大学物理系,合肥,230026
Published: November 2020

XPS measurements have been performed on the orthogonal single phase YBa2Cu3O7 superconductor. The higher valence-like state of Cu is observed clearly. The electronic states corresponding to the peaks in Cu2p and O1s XPS are discussed. It is suggested that the extra holes due to the excess oxygen are created on the O2p orbit. The higher valence-like state of Cu corresponds to the combination of Cu3d9L and Cu3d10L3 states.
GRAVITATIONAL AND CONFORMAL GAUGE THEORY IN INTEGRABLE WEYL SPACE
Authors: ZHAO SHU-CHENG  ,   兰州大学物理系,兰州,730000;中国科学院理论物理研究所客座
Published: November 2020

The conformal gauge field theory in the integrable Weyl spacetime is proposed. Based on this, a formula of the inertial mass field, m = kΦ(x), is obtained. The meaning of k is shown to be the gravitational charge and Φ(x) the inertial factor. By use of the geometrical characteristics of Weyl salar Φ(x), the conformal symmetry is shown to be broken spontaneously and the Eistein gravity emerged. The theory predict the existence of Weyl vector meson, which is massive and can not interact with any other matter fields.
UNDERCOOLING AND FORMATION OF SUPERSA-TURATED SOLID SOLUTION OF Pd-Ni-P IN A 20m DROP TUBE
Authors: XU YING-FAN  , CHEN HONG  , WANG WEN-KUI  ,   (1)中国高等科学技术中心(世界实验室); (2)中国科学院国际材料物理中心,沈阳110015; (3)中国科学院物理研究所,北京100080
Published: November 2020

Undercooling behavior of Pd43.5Ni43.5P13 alloy was studied in a 20m drop tube. The solidified droplets were spheres with size ranged from 0.2 to 2.5 mm in diameter. The samples were examined by X-ray diffraction, scanning electron microscopy and X-ray energy dispersive spectrum. The results showed that when the alloy solidified in nitrogen at pressure of 1.8×104Pa, a near single phase of Pd-Ni-P fcc solid solution was obtained. This fact suggests that a partitionless solidification may occur during the solidification of the alloy in free fall. In addition, when the droplets solidified in nitrogen at pressure of 8.0×104Pa, an amorphous phase presented in the sample. This indicate that the sample had partially undercooled below the glass transition temperature Tg.
INSULATOR-METAL TRANSITION AND SUPERCONDUCTI- VITY INDUCED BY HOLE DOPING IN Y1-xCaxBa2Cu3O6 SYSTEM
Authors: ZHAO YONG  , ZHUGE 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

By the substitution of Ca for Y, the holes are introduced into the insulating host material YBa2Cu3O6, and an insulator-to-metal transition, as well as superconductivity at 60K, is observed. The measurements of crystal structure, resistivity and ac susceptibility are performed, and the results indicate that the CuO planes with sufficient carrier concentration is the important condition for sustaining the high-Tc superconductivity.
BAND-EDGE DISCONTINUITIES AND COUPLING BETWEEN WELLS FOR GaAs/Al0.23Ga0.77As DOUBLE QUANTUM WELLS
Authors: PAN SHI-HONG  , HUANG HUI  , ZHANG CUN-ZHOU  , R. N. SACKS  ,   (1)United Technologies Research Center,East Hertford,Connecticut,U. S. A.; (2)南开大学物理系,天津300071
Published: November 2020

We report a detailed photoreflectance study at 300 and 77K of a set of GaAs/ Al0.23Ga0.77As double quantum well samples with different barrier widths Lb0.23Ga0.77As valence band to the first electron confined state and from the first light hole confined state to the bottom of the Al0.23Ga0.77As conduction band. By using these transitions the conduction band-edge discontinuity has been determined to be Qcb</sub<40?, we have observed a evident splitting of both transitions 11H and 11L into symmetrical and anti-symmetrical components. The experimental results of the splitting have been compared with theoretical calculations. A shouler-like peak at the higher energy side of the 11H transition, which can not be fitted by the standard PR line shape, was resolved at the 77K PR spectra. If he shoulder-like peak is assigned to be the band-to-band transition, we can determine the exciton binding energy to be approximately 8 meV.
STUDIES OF THE MAGNETIC PROPERTIES AND 57Fe CONV-ERSION ELECTRON M?SSBAUER SPECTRUM OF THE MATELLIC Fe/Pd SUPERLATTICES
Authors: LI MIN  , MEI LIANG-MO  ,   (1)山东大学物理系,济南250100; (2)山东大学物理系,济南250100;山东省电子工业局,济南250011
Published: November 2020

The structural and magnetic properties of the two sources deposited Fe/Pd superlattices were studied. The samples were prepared by keeping the thickness of Pd layers dpd at 30? and varying dFe from 56 to 5.7?. The reduced saturation magnetization of Fe/Pd superlatti-ces, σt increased with the decrease of dFe this was due to the polarization effect of Pd. The effective thickness of polarization effect dpd was found as about 10? at 0K. The temperature dependence of magnetization followed Bloch T3/2 law in the range of 7-300K. and the spin-wave stiffness constant B increased with the decrease of dFe The Curie temperature, Tc decreased with dFe The 57Fe conversion electron M?ssbauer spectrum illustrated that the polarization effect existed among the layers, and there were no magnetic enhancing effect and "dead layer effect" on the Fe atoms at the interfaces.
FORMATION OF K-O COMPLEXES IN COADSORPTION OF CO AND K ON Cu(lll) SURFACE
Authors: ZHU LI  , BAO SHI-NING  , XU YA-BO  , XU CHUN-YI  ,   浙江大学物理系,杭州310027;中国科学院表面物理国家重点实验室,北京100080
Published: November 2020

CO, O and K coadsorption on Cu(lll) at oom temperature was investigated using high resolution electron energy loss spectroscopy (HREELS). The experimental results show that CO can adsorb on Cu(lll) surface precovered with K at room temperature and coadsorption of CO and K produce the K-O complexes. The K-O complexes can form only from the depolarized K at higher K coverage (θk>0.04).
HIGHER DIMENSIONAL VAIDYA-LIKE SPACE-TIME WITH ELECTROMAGNETIC FIELDS AND COSMOLOGICAL CONSTANT
Authors: LI JIAN-ZENG  ,   北京广播学院,北京100024
Published: November 2020

The higher dimensional exterior solutions of Einstein equations with cosmological constant for a charged radiating sphere is obtained. And the different expressions of the electromagnetic energy-momentum tensor in higher dimensional space-time are also investegated.
CLUSTER SIZE DISTRIBUTION IN THE n-POLYMER COAGULATION PROCESSES AND THE JOINT COAGULATION PROCESSES
Authors: XUE YU  , KONG LING-JIANG  , WENG JIA-QIANG  ,   广西师范大学物理系,桂林541001
Published: November 2020

We have considered coagulation processes containing n-polymer interactions by means of a generalized Smoluchovski's equation, which is solved as a monodisperseinitial-value problem to the kernel: K(i1,i2,…,in)=A sumfrom i=1 to n i1+B, K(i1,i2,…,in)=A sumfrom i=1 to n i1. According to the connection between model K(i1,i2,…,in)=A sumfrom i=1 to n i1+B and K(i1,i2,…,in)= S(i1)S(i2)…S(in)(S=Ak+B),we obtain the pre-gel solution of the latter model. We also study a kind of joint coagulation process containing two-polymer and three-polymer collisions with the kernel K2(i, j)=i+j and K3(i,j,k) = i+j+k and get the explicit expression of Cm(t). Finally, we discuss the long-term behavior of Cm(t), Which can be extented to the general case.
SUPERCONDUCTIVITY IN Y1-xCaxBa2Cu3-xMxO7-δ (M=Fe, Ni) SYSTEMS
Authors: XU ZHU-AN  , OUYANG SONG  , FANG MING-HU  , WANG JING-SONG  , ZHANG SHI-YONG  , SHEN MING  , ZHANG QI-RUI  ,   (1)江西省吉安师范专科学校,吉安343009; (2)浙江大学化学系,杭州310027; (3)浙江大学物理系,杭州310027
Published: November 2020

The relation of crystal structure, oxygen content, normal state resistivity with. temperature and superconducting critical temperature of Y1-xCaxBa2Cu3-xMxO7-δ(M = Fe, Ni) systems have been studied. In comparison with YBa2Cu3-xMxO7-δ (M = Fe,Ni) systems, it is found that the superconducting Tc of Y1-xCaxBa2Cu3-xFexO7-δ system is remarkably higher than that of YBa2Cu3-xFexO7-δ system with the same x value. On the contrary, the Tc of Y1-xCaxBa2Cu3-xNixO7-δ system is lower than that of YBa2Cu3-xNixO7-δ system. These results show that the variation of the carrier concentration (nH) due to Ca and Fe substitutions has been compensated and the sharp decreases of nH and Tc are prevented when Ca and Fe simultaneously substitute for Y and Cu(I). But in the case of Ca and Ni simultaneous substitutions, the compensation of the carrier concentration is not important and the correlation of Ca and Ni substitutional effects is weak. We suggest that the carrier concentration is an essential factor to determine Tc when the element substitution occurs out of the CuO planes, such as in Y1-xCaxBa2Cu3-xFexO7-δ system, but the pair-breaking effect is more important when Ni2+ ions substitute mainly into Cu(II) sites in Y1-xCaxBa2Cu3-xNixO7-δ system and Tc is directly suppressed by the pair-breaking effect.
THEORY OF (e, 2e) COLLISIONS IN COMPLEX ATOMS
Authors: Qian Qing  , Liu Qiang  , Xu Xiang-dong  , Tian Jia-he  , Chen Xue-jun  ,   (1)清华大学现代应用物理系,北京,100084; (2)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

The multiple-scattering expansion for (e, 2e) collisions in H-atoms is extended to the case of complex atoms.
A STUDY ON THE 2% PdO/Al2O3 BY MEANS OF FREE POSITRON ANNIHILATION TECHNIQUE IN THE SOLID SURFACE LAYER
Authors: SHI ZHI-KANG  , HUANG CUN-PING  ,   中国科学院福建物质结构研究所,福州,350002
Published: November 2020

In this work, we studied the relationship between heat treatment and space structure of the PdO layer in 2% PdO/AL2O3 by the positrons from 22Na radiative source, and calculated its grain size by the positron annihilation parameters, demonstrating that the free positron annihilation technique for the solid surface layer can be applied to catalyst research.
A NEW THEORY AND EXPERIMENT ON ELECTRICAL AGING AND BREAKDOWN OF SOLID DIELECTRICS
Authors: LIU FU-DE  , YANG BAI-TUN  , TU DE-MIN  , LIU YAO-NAN  ,   西安交通大学,西安,710049
Published: November 2020

According to first-order capture equation, a kinetic theory for trap creation in solid dielectrics is proposed in this paper. Taking a certain trap density as critical condition of electrical breakdown, it is found that the dielectrical lifetime is proportional to the exponent of electrical strength. Such a theory is consistent with the widely used emperical formula and agrees with experimental results.
INTERACTION OF ULTRASONIC WAVE WITH VOID- CONTAINING LAYER IN SOLID
Authors: WANG YAO-JUN  ,   南京大学声学研究所,南京,210008
Published: November 2020

Using a general model for sound reflection from multilayered media, we present in this paper the expressions for sound reflection and transmission coefficients on voidcontaining interface layer in solid and derive the characteristic equation for symmetric and antisymmetric modes of the interface waves along the layer. The method for evaluating the effective elasric moduli of void-containing solid is also introduced. The numerical calculation given in this paper shows the influence of the void volume concentration and layer thickness on the sound reflection coefficients and interface wave velocity, providing a theoretical basis for inverse deduction of the mechanical properties of void-containing layer based on ultrasonic measurements.
A STUDY ON ROTATIONAL RELAXATION OF GAS PHASE C2H2 BY RAMAN UV OPTICAL DOUBLE RESONANCE
Authors: GAO WEN-BIN  , R. DOPHEIDE  , H. ZACHARIAS  ,   (1)Fachbreich physik,Universitat/GHS Essen,F. R. Germany; (2)Fakultat fur physik,Universitat Bielefeld,P. R. Germany; (3)杭州电子工业学院,杭州,310017
Published: November 2020

In the present work, the selective preparation of C2H2 in discrete rotational states of the infrared inactive vibrational v mode in its electronic ground state (X1∑g+,v″2=1,J″= 9,11 and 13) is achieved by stimulated Raman excitation. From the UV laser induced fluorescence, A1Au(v′3=←X′∑g+ (v"2=1), the C2H2-C2H2 collisional R-R deactivation rate constants are measured. They are (7.96±1.04)×10-10cm3s-1 for J"= 9, (8.79±0.97)×l0-10cm3s-1 for J"= 11 and (8.76±0.88)×10-10cm3s-1 for J" = 13. The multiquanta R-R energy transfer rcte constants for trdnsitions from the initial pumped level to other different rotational states (v"2= 1, J" = 1,3,5,7,9,11,13,15) have been extracted directly.
A NOVEL SMALL-PERIOD WIGGLER FOR FREE-ELECTRON LASERS
Authors: FENC BI-BO  , WANG MING-CHANG  , WANG ZHI-JIANG  , LU ZAI-TONG  , ZHANG LI-FEN  , FENG CHENG-SHI  ,   中国科学院上海光学精密机械研究所,上海,201800
Published: November 2020

A novel small-period wiggler configuration constructed by sheet of bifilar-helix with ferro-core for free-electron lasers is proposed. The performance characteristics of the wiggler prototype with 10mm period are measured. The field as high as 500G to 1kG have been obtained. The amplifier designs for operation at 190 GHz using modest electron beam energies in the range of 400-500 keV are presented.
APPLICATION OF THE IMPROVED KLEED/CMTA METHOD ON Si(111) 31/2×31/2-Al SURFACE
Authors: JIA JIN-FENG  , ZHAO RU-GUANG  , YANG WEI-SHENG  ,   北京大学物理系,北京100871
Published: November 2020

In this paper, we carried out an improved kinematic low energy electron diffraction and constant momentum transfer averaging (KLEED/CMTA) analysis of aSi(111)31/2×31/2-Al structure After a thorough optimization of the parameters, we came to the conclusion that T4 model is the best, which gives an excellent agreement with experiment curves(RVHT = 0.158). Atomic coordinates and bond lengths of the model have been determined for Al atoms and all Si atoms in the first six layers of the substrate. None of the bond-length deviations from the bulk value is larger than 5% and within an error bar of 0.05A, all of the parameters (except a lateral displacement) are consistent with the conclusion of DLEED. The successful application of the KLEED/CMTA method to such a complicated surface structure indicates strongly that the method is really very poweriul and reliable,and thus has great potential in surface structure analysis.
STUDY OF DEFECTS IN LOW-DOSE P+ IMPLANTED AND RAPID THERMAL ANNEALED SILICON
Authors: LI XIAO-LEI  , LU FANG  , SUN HENG-HUI  , HUANG QING-HONG  ,   复旦大学物理系,上海200433
Published: November 2020

Defects charactistics of low-dose p+ implanted silicon after rapid thermal annealing (RTA) was studied. RTA at 600℃ can activate most implanted ions. The defects in samples after RTA below 800℃ are found mainly the ion-implantation induced damage defects. Dislocations are found in samples after RTA above 800℃. The ion-implantation damage defects and thermal stress during quenching step are responsible for the formation of dislocations. The concentration of defects in 1100℃RTA sample began to increace. Slip dislocations are induced by thermal stress in the wafer.
ANALYSIS OF THE HIGH Tc OXIDE SUPERCONDUCTORS FROM THE GOLDEN COORDINATES
Authors: JIN GUANG-HAI  , ZHANG LI-YUAN  ,   北京大学物理系,北京100871
Published: November 2020

In this paper, more than sixty high-Tc oxide superconductors are analysed again with Vil-lars coordinates. Moreover, we introduce two new coordinates, namely, the average electrone-gativity and chemical combination valence. It is found that the high-Tc oxide superconductors are distributed more concentratively in the diagram of these new coordinates.
SPECTRA AND CRYSTAL PARAMETERS OF HOST LUMINESCENT CRYSTAL Na5Eu(MoO4)4 UNDER HIGH PRESSURE
Authors: GUO CHANG-XIN  , LI BI-LIN  ,   中国科学技术大学物理系,合肥230026
Published: November 2020

Na5Eu(MoO4)4 is a stoichiometrlc host luminescent material. The light emessioB comes from high concentration host ions Eu3+. In the present work, the effects of hydropressure on fluorescence of Eu3+ in Na5Eu(MoO4)4 are invistigated under 0-5.0 GPa using a diamon anvil high pressure microspectroscopic system. According to crystal field theory, the energy level fexpressinns of Eu3+ (in approximatry D2d symmetry site) are calculated and fit with the experimental data of energy levels, under high pressure, then the ratios of crystal parameter variation △Bkq (kq= 20,40 44, 60 and 64) with pressure variation △P are determind. A comparison of above results with that of YVO4:Eu3+, in which Eu3+ is an active impurity, is also made.
ANALYSIS ON LiNbO3 CRYSTAL RESONATOR EXCITED BY DISTRIBUTED PIEZOELECTRIC SOURCE
Authors: LI SHI-CHEN  ,   天津大学精密仪器系,天津300072
Published: November 2020

In order to discribe piezoelectric strain optical modulator (PESOM), we analyzed LiNbO3 crystal resonator excited by distributed piezoelectric source in detial in this paper. The quantitative results of structure of strain field are obtained in one-dimension approximation for PESOM.
ANALYSIS ON LiNbO3 CRYSTAL PIEZOELECTRIC RESONATORAND LASER MODE LOCKER
Authors: LI SHI-CHEN  ,   天津大学精密仪器系,天津300072
Published: November 2020

Axis-cut LiNbO3 crystal piezoelectric strain optical modulators (PESOM)and its properties when they used as laser mode lockers are analysed in detail. We have proved that x-cut plate is the best form used for laser mode locker. And y-cut or z-cut plate will result in loss modulation and frequency modulation at the same time, so in principle they are not suitable for using as laser mode locker operating at steady state.
CALCULATION OF LATTICE HEAT CAPACITY OF LAYERED MATERIAL BASED ON A SIMPLE MODEL
Authors: ZOU NAN-ZHI  , LIANG KAI-FENG  , LIN ZHI-CHENG  ,   中山大学物理系,广州,510275
Published: November 2020

We calculate the lattice heat capacity of layered material based on a simple model with cubic structure and Born potential. It is shown that interface states affect the lattice capacity obviously when the thickness of layer is relatively small (less than several tens of single la-years). With the increasing of thickness of the layer, the lattice capacity decreses and is nearly independent of interface states and the thickness of the layer. We also give a comparison of the lattice capacity of aperiodic superlattice with that of periodic superlattice.
FLUX MOTION AND CRITICAL CURRENT CHARACTERISTICS OF Ag-SHEATHED Bi1.8Pb0.4Sr2Ca2.2Cu3Oy TAPES
Authors: ZENG ZHAO-YANG  , SHI KE-XIN  , YU ZHENG  , DING SHI-YING  , ZHOU YI-RU  , YE BING  ,   (1)北京有色金属研究总院,北京100088; (2)南京大学物理系固体微结构物理国家重点实验室,南京210008
Published: November 2020

Ag-sheathed Bi1.8Pb0.4Sr2Ca2.2Cu3Oy superconducting tapes were prepared. Microstruc-ture examination shows that it were made of highly textured Bi2223 single phase. Measurements of transport properties in liquid nitrogen and field lower than 1T reveal that Jc(T,B,θ, φ) and R(T,B,θ,φ) of this material are θ dependent and φ independent, where θ is the angle between magnetic field and ab plane and φ is the angle between magnetic field and transport current. Activation energy of flux lines was gained. The Arrhenius relation of R(T,B) was observed and activation energy of flux motion was determined. The transport characteristics and the activation energy are explained as the thermally activated flux line diffusive motion over intrinsic flux pinning barrier by means of nucleation of two-dimensional pancake vortex pairs.
MICROWAVE JOINING OF THE Bi-BASED 2223 SUPERCONDUCTOR AND ITS MICROSTRUCTURE FEATURES
Authors: CAI JIE  , XIE XIAO-MING  , LI XIANG-TING  , CHEN TING-GUO  , HUANG XIAO-XIAN  , GUO JING-KUN  ,   (1)中国科学院上海硅酸盐研究所,上海200050; (2)中国科学院上海冶金研究所,上海200050
Published: November 2020

Microwave joining developed rapidly in recent years, because of its advantages such as 1)low energy consnmption; 2)rapid heating rate; 3)high quality joint. Microwave joining of the Bi-based 2223 superconductor was studied with the results showing, after joining at 900-1000℃ for 10 minutes and post treatment at 855℃ for 60 hours, Tc restored to 107 K, the same as that of the original sample. Electron probe technique was used to study the microstructure features before and after joining.
QUANTUM THEORY FOR FARADAY EFFECT AND IT'S TEMPERATURE DEPENDCE IN PARAMAGNETIC CeF3 CRYTALS
Authors: ZHANG HUI-QI  , JIANG ZHENG-SHENG  , XU YOU  , DUAN MING-QIAN  , YANG GUI-LIN  ,   南京大学物理系,南京,210008
Published: November 2020

The Faraday rotation caused by electronic transitions between the 4f and 5d states of Ce3+ ions in paramagnetic CeF3 crystals is calculated. The crystal field is an important perturbation on the energy levels. An external magnetic field, together with an additive magnetic field introduced phenomenologically in our paper, would spilt every 4f state into two sublevels. The dipole transitions between these sublevels, and 5d states induce the Faradap effect.The Verdet constant at 0.6328 μm in the temperature range of 60-300 K is obtained. It is shown that our calculation is in good agreement with experiment.
AN ANY-STATE-INVERSIONLESS LASER
Authors: LUO ZHEN-FEI  , XU ZHI-ZHAN  , ZHANG WEN-QI  ,   中国科学院上海光学精密机械研究所,上海201800
Published: November 2020

An energy-level system with upper-level coherence driven by an external field is investigated. It is shown that a laser may develop without the need of population inversion in any state (bare or dressed states).
MEASUREMENTS OF X-RAY CONVERSION EFFICIENCY IN 1.2 keV REGION FROM Cu AND-NaF PLASMA PRODUCED BY 1.06 AND 0.53μm LASER
Authors: HE SHAO-TANG  , HUANG WEN-ZHONG  , SUN YONG-LIANG  , YANG SHANG-JIN  , CAI YU-QIN  , HE AN  , KONG LING-HUA  , CHUNYU SHUTAI  ,   西南核物理与化学研究所,成都610003
Published: November 2020

This paper presents the measurement methods and the experimental results of X-ray conversion efficiency in 1. 2 keV region from Cu and NaF plasma produced by 1.06 and 0.53μm laser. These results showed that X ray conversion efficiency in Cu plasma is 4-5 times as high as that in NaF plasma with the laser intensity in 1×1013—1×1014W·cm-2 and wavelength of 1. 06 and 0. 53μm. The X-ray conversion efficiencies in Cu and NaF plasma produced by 0. 53μm laser are about 2 times as high as that by 1.06μm laser.
TUNABLE-SAMPLING-DEPTH ELECTRON ENERGY LOSS SPECTROSCOPY STUDIES OF Sn/Si INTERFACE
Authors: GAO SHAN-HU  , ZHANG YUN  , XUN KUN  , ZHAO RU-GUANG  , YANG WEI-SHENG  ,   (1)北京大学物理系,北京100871; (2)北京大学物理系,北京100871;烟台大学物理系,烟台264005
Published: November 2020

In the present paper, the interfacial reactions at the interfaces of the Sn/Si system have been studied by means of tunable-sampling-depth electron energy loss spectroscopy (TELS) in conjunction with low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES). It is found that, depending on the orientation of the silicon substrates, the interfacial reactions are qualitatively different. No intermixing of Sn with Si occurs at the as-deposited Sn/Si (111) interfaces and the Sn/Si (111) interfaces annealed at temperatures lower than 400℃. However, Sn intermixes with Si at the Sn/Si (111) interfaces annealed at temperatures between 400 adn 700℃, forming a Sn/Si intermixing layer with a maximum thickness of about 1nm. The bulk plasmon peak of this intermixed layer on the ELS curve is at 15. 5eV. No detectable intermixing of Sn with Si has been found at the Sn/Si (001) interfaces annealed at any temperature. Annealing at increasing temperatures only makes the homogeneous Sn layer to become islands, and the islands become smaller and eventually disappear at a temperature higher than 1000℃. A prolonged annealing at 550℃ gives rise to the appearance of (113) facets on the Sn/Si (001) surface, as shown by the 'moving spots' on the LEED pattern.