bluuebunny/crossref_metadata_2025 huggingface dataset:
DYNAMIC STORAGE TIME MEASUREMENTS OF N-TYPE Hg1-xCdxTe METAL-INSULATOR-SEMICONDUCTOR DEVICES
Authors: HUANG HE  , TANG DING-YUAN  , TONG FEI-MING  , ZHENG GUO-ZHEN  ,   (1)湖南大学应用物理系,华南师范大学物理系; (2)中国科学院上海技术物理研究所
Published: December 2020

Dynamic storage time has been measured for x=0.31 n-type Hg1-xCdxTe metal-insulator semiconductor (MIS) devices over temperature range of 68 to 250K. The theoretical calculations have been made in analysing the mechanisms of dark currents. The results point out that the indirect tunnel current, which involves a thermal transition of an electron from the valence band to a band-gap state followed by tunneling into the conduction band, is the main dark current source, especially in low-temperature (about 77K) high-field regime and will dominate the electrical properties of the MIS devices.
PHASE DIGRAM OF SPIN 1/2 XXZ CHAIN
Authors: CHEN ZHI-JIAN  , ZHANG YU-MEI  , XU BO-WEI  ,   (1)上海交通大学物理系,上海200030; (2)上海交通大学物理系,上海200030中国科学院理论物理研究所,北京100080; (3)同济大学物理系,上海200092
Published: December 2020

By mapping the spin 1/2 XXZ quantum chain to sine-Gordon model, we have analyzed the phase diagram of sine-Gordon model using tke method of gaussian wave functional and taking the large momentum cutoff. We have obtained the mas-sless region which agrees with the exact solution quite well.
SINGLE-ELECTRON ANALYSIS OF THE SPACE-CHARGE WAVE IN FREE-ELECTRON LASERS
Authors: LI ZHI-KUAN  ,   承德民族师范高等专科学校物理系,承德067000
Published: December 2020

In this paper, we analyse the effect of space-charge wave in free-electron lasers from the single-particle model theory. A iterative computing method is presented. The calculations have shown that the first step solution of the couples of three waves in free-electron lasers is in accordance with the result obtained; the second order solution shows a more complex structure of the space-sharge wave.
DIAGNOSTICS OF ELECTRON DENSITY OF LASER-PRODU-CED PLASMA FROM THE XUV SPECTRA OF AgXIX
Authors: WANG WEN-ZHONG  , ZHANG TAN-XIN  , HE ZHAO-TANG  , GU YU-QIU  , LONG YONG-LU  , JIANG WEN-MIAN  ,   (1)北京应用物理与计算数学研究所,北京100088; (2)西南核物理与化学研究所,成都610003
Published: December 2020

The XUV spectra from AgXIX of laser-produced plasma are measured. The density dependence of △n= 0 (4-4) transitions from AgXIX has been studied in a density range 1017-1022 cm-3 with the collisional radiative model. The theoretical model included the effect of cascading from n= 5 states on the population of the n =4 levels. In addition, optical depth effects on the line intensities were considered. The two transitions of 4d2D5/2 4f2F7/2 and 4p2P3/2-4d2D5/2 remain close to each other and are unblended with other lines. Calculations of their radiation intensity ratio vs the electron density are performed. Electron density of laserproduced plasma has been deduced from the ratio.
PEAK ENERGY FOCUSING OF PHOTOLUMINESCENCE FROM POROUS SILICON DURING STORING IN AIR OR 200℃ THERMAL OXIDATION
Authors: ZHANG BAI-XIN  , ZHANG LI-ZHU  , SONG HAI-ZHI  , YAO GUANG-QING  , DUAN JIA-DI  , TAO GUO-QIANG  ,   (1)北京大学化学系,北京100871; (2)北京大学物理系,北京100871
Published: December 2020

Porous silicon (PS) samples with photoluminescence (PL) peak energies in the range of 1.4 to 2.0 eV were obtained by varing anodization conditions. 45 pieces of PS sample were stored in air for one year, and 102 pieces of PS sample were thermally oxidized at 200℃for 200 hours. After these two kinds of oxidation processes, PL peak energies of all PS samples focused to around 1.70-1.75eV. Supposing that luminescence centers with luminescence energies around 1.70-1.75eV exist in SiOx(x - 2) layers covering nanoscale silicon in fully oxidized PS, reported can be explained by the quantum confinement/luminescence centers model.
STUDY OF THE EXCITATION OF A ROTARY ECHO PULSE SEQUENCE IN SOLID-STATE NMR SPECTROSCOPY
Authors: LI GEN-YING  , XU XUE-CHENG  ,   华东师范大学分析测试中心,上海200062;
Published: December 2020

perimental parameters is proposed in the present article. That the superiority of the suggested pulse sequence over the conventional two 90?echo sequence is confirmed by theoretical calculation and experimental results.
GROWTH OF METASTABLE fcc Mn THIN FILM ON GaAs(00l) AND ITS ELECTRONIC STRUCTURE STUDIED BY PHOTOEMISSION WITH SYNCHROTRON RADIATION
Authors: CHEN YAN  , DONG GUO-SHEN  , ZHANG MING  , XU MIN  , JIN XIAO-FENG  , LU ER-DONG  , PAN HAI-BING  , XU PENG-SHOU  , ZHANG XIN-YI  , FAN CHAO-YANG  ,   (1)复旦大学李政道物理学综合实验室,应用表面物理国家重点实验室,上海200433; (2)浙江大学物理系,杭州310027; (3)中国科学技术大学国家同步辐射实验室,合肥230026
Published: December 2020

The epitaxial growth of metastable fcc Mn thin films on GaAs(001) surface has been achieved at a substrate temperature of 400K. The development of the fcc Mn thin films as a function of coverage is studied by photoemission with synchrotron radiation. The electron density of states below the Fermi edge of the fcc Mn phase is measured A significant difference of the electronic structures is observed between the metastable fcc Mn phase and the thermodynamically stable α-Mn phase. Possible mechanisms are proposed to interprete the experimental result.
A STRUCTURAL STUDY ON (Bi_(2-x)Pb_x)Sr_2CuO_y(0.1≤x≤0.6) SERIES CRYSTALS BY X-RAY PRECESSION METHOD
Authors: PAN GUO-QIANG  , S.МegtertG.Collin  ,   (1)Laboratoire,dePhysiquedesSolides,Bt,510.UniversiteParis-Sud.91405Orsay,France;Laboratoirc,L(?)onBrillouin,CEA-CNRS,Bt.563,CENSaclay,91191,Gif-sur-Yvette,France; (2)中国科学技术大学合肥国家同步辐射实验室,合肥230029
Published: December 2020

In this paper, a structural study on series crystals of (Bi2-xPbx)Sr2CuOy (0.1≤ x ≤ 0.6) by X-ray precession method is reported. We found that in the lead substitution regions 0.4≤x≤0.5 this system is formed by two interpenetrating subsystems. One subsyst
FORMATION AND EVOLUTION OF FCC PHASE IN TITANIUM NANOPARTICLES
Authors: YANG MING-CHUAN  , XU JIAN  , SUN XIU-KUI  , WEI WEN-DUO  , HU ZHUANG-LING  ,   中国科学院金属研究所快速凝固非平衡合金国家重点实验室,沈阳110015
Published: December 2020

Titanium nanoparticles were synthesized by gas condensation method, where the particles with different average diameters were obtained by varying the gas pressure in the atmosphere of argon and helium, respectively. The structure, morphology and compositi
DIFFUSION COEFFICIENT MEASURED BY IMPEDANCE SPECTROSCOPY
Authors: WANG GANG  , YANG GUO-QUAN  , GUAN DI-HUA  , JIANG LI  , PA SI-KUA-LI-MAO-LUO  , PI SI TUO YAN-ZHAN FO LAN KE  , JIE SI-SHENG  ,   (1)北京科技大学,北京100083; (2)意大利国家研究中心; (3)意大利罗马大学; (4)中国科学院物理研究所,北京100080; (5)中央民族大学,北京100081
Published: December 2020

To have a quantitative estimate of the speed of Li+ diffusion in Nal+xV3O8 (L-T.), for example, impedance tests were run for different intercalation levels. The values of 10-8-10-9 cm2·s-1 have been obtained and matched the fast kinetics observed.Possible
MECHANISM OF THE COERCIVITY FOR THE GRANULAR SOLID
Authors: WANG JIAN-PING  , LUO HE-LIE  ,   中国科学院物理研究所,北京100080
Published: December 2020

The Fe-SiO2 and Fe20Ni80-SiO2 granular solid has been prepared using a sol-gel method. The structure and the phase constitution of them is measured by X-ray diffraction, Mossbauer spectra and the morphology of them is observed using transmission electron
GLOBAL QUANTAL CANONICAL SYMMETRY PROPERTIES FOR A SYSTEM WITH A SINGULAR LAGRANGIAN
Authors: LI ZI-PING  ,   北京工业大学应用物理系
Published: December 2020

Starting from the quantization formalism of the phase-space path integral for a system with a singular Lagrangian, the generalized canonical Ward identities and conserved charges at quantum level are deduced under the global transformation in extended phase space. In general, the quantal conserved charges are different from classical ones. We give a preliminary application to Yang-Mills theory,the new quantal conserved charges are found.
THE OBSERVATIONS OF DIFFRACTED AND TRANSMITTED ROCKING CURVES IN BRAGG CASE NEAR ABSORPTION EDGE
Authors: ZHOU SHENG-MING  , ZHAO ZONG-YAN  , QI ZE-MING  , XU ZHANG-CHENG  , TOMOE FUKAMACHI  , RIICHIROU NEGISHI  , MASAMI YOSHIZAWA  , TETSUO KANAJIMA  ,   (1)安徽大学物理系; (2)日本高能物理研究所放射光实验设施; (3)日本琦玉工业大学
Published: December 2020

The diffracted and transmitted rocking curves for GaAs(600) in the symmetric Bragg case have been measured under the condition of extremely anomalous scattering near the Ga K-absorption edge, and then compared with the corresponding results calculated in the dynamic theory of X-ray diffraction. We have thereof pointed out that the transmitted rocking curves near the atomic absorption edge in Bragg case are useful in the study of anomalous scattering.
ELECTRON-PHONON INTERACTIONS AND PHONON EXCITATIONS IN ONE-DIMENSIONAL SYSTEMS
Authors: WANG LIAN-TAO  , WU CHANG-QIN  ,   复旦大学物理系
Published: December 2020

Electron-phonon interactions and phonon excitations are studied on the models both for the halogen-bridged moxed-valence transition-metal linear complexes(MX) and the molecular crystals (MC). The renormalized phonon dispersions are obtained under the adiabatic approximation. We find:(1) the electron-phonon interactions are different for the two models, and then the renormalization correction on the acoustic phonons is negligible for the MX model whereas the correction is obvious for the MC model;(2) no gap exists between the two branchs of phonons for the two models, which is different with that of the Su-Schrieffer-Heeger model for polymers.
INTERSUBBAND ABSORPTION COEFFICIENTS IN A QUANTUM WELL Ge0.3Si0.7/Si/Ge0.3Si0.7 WITH BARRIER-δ-DOPING
Authors: XU ZHI-ZHONG  ,   复旦大学物理系
Published: December 2020

The electronic structures and intersubband absorption coefficients of Ge0.3Si0.7/Si/Ge0.3Si0.7 quantum wells with barrier-δ-doping grown on Ge0.3Si0.7(001) substrates are consistently calculated in the envelopefunction approach. The dependences of the absorptivities on the well widths, δ-doping position and δ-doping concentration are discussed . At last, the frequency shift caused by the depolarization effects of highly dense two-dimensional electrons are studied.
THE EXCITATION-AUTOIONIZATION OF Na-LIKE Cu ION
Authors: TENG HUA-GUO  , XU ZHI-ZHAN  , HU WEI  , WANG YAN-SEN  , FANG DU-FEI  ,   (1)复旦大学物理二系; (2)中国科学院上海光学精密机械研究所
Published: December 2020

The excitation autoionization of Na-like Cu ion origination from inner-shell excitations of 1s22s22p６3s→1s22s2２ｐ5３ｓ３ｌ（ｌ＝０，１，２） was investigated in some detail. The inner-shell excitation cross sections were calculated in the distorted Columob-Born exchange approximation and the target ionic states were obtained in a single configuraton approximation. The autoionizing branch ratios were calculated by using both single configuration and configuration interaction wavefunctions. The results showed that, at an incident electron energy of 1090 eV, the correlation enhancement of excitation autoionization cross sections was mainly due to 1s22s22p53s3d configuration,in which the correlation effects increasd the excitation autoionization cross sections nearly to a factor of 2. The excitation autoionization cross sections for 1s22s22p53s2 were reduced about 36% when compared with the results of single configuration approximation. Howecer, The configuration interaction had only a slight effect on the autoionization cross sections for excitation to 1s22s22p53s3p configuration.
LOCAL SYMMETRIES AND CONSTRAINTS IN SELF DUAL GRAVITY
Authors: MA YONG-GE  , LIANG CAN-BIN  ,   北京师范大学物理系
Published: December 2020

In Ashtekar's formalism, the phase space of general relativity is imbedded into the phase space of complex SU(2) Yang-Mills theory. In this paper, the approach of analyzing local symmetries and constraints in ordinary feild theories is generalized to the complex field theory, the phase space of the Ashtekar formalism is constructed from the configuration space of the self dual Palatini formalism, and the relationship hetween local symmetries of the configuration space and constraints on the phase space is then discussed.
DIRECT TRANSPORTABLE MODEL OF BROWNIAN MOTOR
Authors: ZHAN YONG  , BAO JING-DONG  , ZHUO YI-ZHONG  , WU XI-ZHEN  ,   (1)北京气象学院基础科学系; (2)中国原子能科学研究院; (3)中国原子能科学研究院;河北工业大学数理系; (4)中国原子能科学研究院;中国科学院理论物理研究所
Published: December 2020

A system which uses the non equilibrium fluctuating energy to do work is considered as a result of Brownian motor derived by both internal and external noises. The corresponding diffusion model including damping force and double noise sources is proposed. Through the analytical calculation and numerical simulation, the mechanism of the directed motion of the Brownian motor driven by multiplicative noise and the effect of damping force on the steady current in the one dimensional inertia ratchet potential are accordingly expounded and analyzed. As a application, the experimental phenomenon of the stepping motion of the single motor protein is explained.
CALCULATIONS OF THE SURFACE AND DIFFUSION BARRIERS FOR OXYGEN PENETRATION ON METALS AND THEIR OXIDES
Authors: LONG DE-SHUN  , WANG YAN-SEN  , FANG DU-FEI  , TANG JIA-YONG  ,   复旦大学李政道物理学综合实验室
Published: December 2020

Using a simpler calculation scheme, we have investigated the surface penetration barriers and bulk diffusion barriers for oxygen in the simple metals Al,Be,Ca,Mg,Zn and their oxides. The results show that the values of the barriers depend on the crystal structure of the material and on the ability of the lattice to relax during the incorporation process. By comparing the theoretical values of the barriers with the experimental ones, we found that the agreement is basically good.
STRUCTURE AND OSCILLATOR STRENGTH DENSITIES NEAR LⅡ,Ⅲ EDGES OF ARGON
Authors: FENG REN-FEI  , WU SHU-LAN  , LIU YING-HUI  , JI QING  , XU KE-ZUN  ,   中国科学技术大学近代物理系
Published: December 2020

The high resolution fast electron energy loss spectrum for inner shell 2p electron excitation and ionization of argon has been measured in present work at an electron impact energy of 2500eV and a mean scattering angle of 0°. The ionization limits and effective quantum numbers have been- deduced.- The oscillator strength densities for discrete transitions and two ionization continua were- also- determined.
ABSORPTION AND SCATTERED LIGHT OF GOLD DISKS IRRADIATED WITH 0.351μm LASER LIGHT
Authors: LIU SHEN-YE  , TEN HAO  , DING YONG-KUN  , DING YAO-NAN  , SU CHUN-XIAO  , JIN GEN-ZHI  , ZHANG HAI-YING  , CHEN YU-TING  , ZHENG ZHI-JIAN  , TANG DAO-YUAN  ,   西南核物理与化学研究所
Published: December 2020

The experiments used the “Xingguang Ⅱ” laser facility to irradiate gold disks at some chosen angle of incidence. In this paper, we report the absorption and angular distribution of scattered lights of 0.351μm laser light by Au disks. The experiments have shown that the absorption by Au disk is higher than that irradiated with 0.53 or 1.05μm laser light. The angular distribution of scattered lights proves that scattered lights include stimulated Brillouin scattering and specular reflection from critical surface. Based on inverse bremsstrahlung absorption, the absorption obtained by simulation agrees with the experimental results.
COMPUTER SIMULATION OF THE THERMAL FLOW INSIDE THE HIGH PRESSURE CELL(Ⅰ) EQUATIONS AND METHODS OF SOLUTION
Authors: SUN ZONG-QI  , XU JI-AN  , XIE HONG-SHEN  ,   (1)地球科学研究所; (2)中国科学院地球化学研究所; (3)中国科学院金属研究所国际材料物理中心
Published: December 2020

A two-dimensional approximation with axisymmetry was used to deal with the thermal conduction inside the high pressure cell . A numerical method, using a microcomputer, to obtain the static and non-steady distribution of temperature was given. The error of calculation in this method was estimated and an approximate analytical formula for the static distribution of the temperature was also given.
STUDY OF THE DIAMOND FILMS WITH HIGH THERMAL CONDUCTIVITY
Authors: GU CHANG-ZHI  , JIN ZENG-SUN  , Lü XIAN-YI  , ZOU GUANG-TIAN  , ZHANG JI-FA  , FANG RONG-CHUAN  ,   (1)吉林大学超硬材料国家重点实验室; (2)中国科学技术大学物理系
Published: December 2020

The scattering of phonons as main factors infuencing the thermal conductivity were analized theoretically. The thermal conductivity of diamond films was measured by means of the photothermal deflection method with an error of 5%. The effects of methane concentration and grain orientation on thermal conductivity of diamond films were studied. The results showed that (100) oriented diamond-films deposited by microwave plasma chemical vapour deposition method under low methane concentration have higher thermal conductivity.
QUANTUM FLUCTUATION OF MESOSCOPIC CIRCUIT IN SQUEEZED VACUUM STATE
Authors: WANG JI-SUO  , SUN CHANG-YONG  ,   聊城师范学院物理系
Published: December 2020

Starting from equation of motion of an active LC circuit,the quantum fluctuations of the charge and current in the mesoscopic circuit (LC circuit) in the squeezed vacuum state are investigated.
INVESTIGATION OF GROWTH MECHANISM OF NANOCRYSTALLINE SILICON THIN FILMS PREPARED BY HOT-FILAMENT CHEMICAL VAPOR DEPOSITION
Authors: CHEN GUO  , GUO XIAO-XU  , ZHU MEI-FANG  , SUN JING-LAN  , XU HUAI-ZHE  , HAN YI-QIN  ,   中国科学技术大学研究生院物理系;半导体超晶格国家重点实验室
Published: December 2020

The nc Si∶H thin films were prepared by hotfilament vapor deposition.The effect of gas pressure,-high H2 dilution and substrate-to-filament distance on deposition rate,the formation and structure of nc-Si∶H films was systematically studied.The structure of nc-Si∶H was determined using Raman scattering and X-ray diffraction.The temperature distribution was calculated;the travel of radicals evaporated from the filament and the gas-phase reaction were discussed in detail.The results were in agreement with the measurement.
STABILITY ENERGY OF GROWTH-UNIT AND MORPHOLOGY OF SPHALERITE CRYSTALLITES
Authors: YUAN RU-LIN  , SHI ER-WEI  , WANG BU-GUO  , XIA CHANG-TAI  , LI WEN-JUN  , ZHONG WEI-ZHOU  ,   (1)中国科学院上海硅酸盐研究所; (2)中国科学院上海硅酸盐研究所;华东地质学院数学系
Published: December 2020

The zinc-based compound crystals, which are composed of zinc-anion coordinate tetrahedrons have two kinds of structure:one is wurtzite and the other is sphalerite.In this article the formation process and the ideal morphology of the sphalerite crystals are studied by calculating the stability energy of the crystal growth unit on the basis of the model of anion coordination polyhedron.The favorable growth unit for the growth of the sphalerite crystal is the tetrahedron.Thus the ideal morphology of sphalerite crystals is tetrahedron.The growth rate of the positive polar plane is different from that of the negative polar plane.It is proved by the calculation that zincoxide crystals are impossible to exist in sphalerite,so are zincsulphide crystals in wurtzite.
NOTES ON THE QUANTUM INVARIANT AND ON THE-RELATION BETWEEN IT AND QUANTUM PHASE
Authors: LI BO-ZANG  , ZHANG LING-YUN  , ZHANG XIANG-DONG  ,   中国科学院物理研究所和凝聚态物理中心;山西大学理论物理研究所
Published: December 2020

Based on the construction theorem of quantum invariant,the results of Lewis and Riesenfeld are rededuced in a much simpler way and extended significantly.Meanwhile,it is pointed out that the Lewis Riesenfeld phases are in general not of physical meaning unless the invariants take specific forms which have been worked out.As an example,the spin system in a magnetic field is discussed in detail.
ANALYSIS OF THE MULTIVARIATE TIME SERIES-IN AN OBSERVATION WINDOW
Authors: YUAN JIAN  , XIAO XIAN-CI  ,   电子科技大学电子工程系
Published: December 2020

Generally,dynamical analyses of the original systems are limited to some extent by the observational methods.In this paper,by using the method of multivariate singular systems analysis (M SSA),which combines simultaneously information sampling the complete range of the spatial cross correlation function in signals with complex spatio temporal structure,we study the changes of the correlation dimensions and the largest Lyapunov exponents of the multivariate time series in an- observation window.And the characterization of prediction is discussed also with the multi-layer- perceptron.It is shown that when the number of the variates is increased,the complexity is also-- increased and the stability and the characterization of prediction are different.
CONTROLLING OF THE INSTABILITY OF-CHAOTIC MOTION IN AN ION CLOUD
Authors: HAI WEN-HUA  , DUAN YI-WU  , ZHU XI-WEN  , SHI LEI  , LUO XUE-LI  , HE CHUN-SHAN  ,   (1)湖南师范大学物理系; (2)湖南师范大学物理系;中国科学院武汉物理与数学研究所; (3)中国科学院武汉物理与数学研究所
Published: December 2020

Interaction between the detecting field and the ion cloud in an actual Paul trap is described by the Duffing equation.For small damping,the unstable periodic solutions embedded in chaotic attractor and their stability conditions are obtained.Theoretical analysis reveals that the instability of chaotic motion can be controlled by adjusting the control parameters to fit the conditions.Excellent agreement is found between the analytical results and experimental data.
NEAR INFRARED SURFACE ENHANCED RAMAN-SCATTERING OF HALATE IONS
Authors: YE XIAO-LAN  , DENG WEN-JIE  , LIANG ER-JUN
Published: December 2020

Surface enhanced Raman scattering (SERS) of halate ions in silver colloids is studied by near infrared (NIR) laser excitation.Ions of ClO－3 and BrO－3 in silver colloids give rise to SERS bands at about 226 and 158cm－1,respectively while IO－3 ions on colloidal silver surface result in two Raman bands at about 750 and 334cm－1.These results indicate that the interactions of ClO－3 and BrO－3 ions with silver surface are through their lone pair electrons of Cl and Br.Nevertherless,IO－3 ions bond to silver surface through their negatively charged O－.The interaction strength of halate ions with silver are measured to be BrO－3>ClO－3≈IO－3.The enhancements of the Raman modes of pyridine caused by addition of halate ions increase in the order ClO－3－3－3.The enhancement mechanisms in NIR SERS are discussed.
EXACT SOLUTION OF JAYNES-CUMMINGS MODEL UNDER ROTATIONLESS WAVE APPROXIMATION USING-COHERENT-STATE REPRESENTATION
Authors: FANG XI-MING  , FENG MANG  , SHI LEI  , GAO KE-LIN  , ZHU XI-WEN  ,   中国科学院武汉物理与数学研究所波谱与原子分子物理国家重点实验室
Published: December 2020

In this paper, a new approach of exact solution of Jaynes-Cummings model under rotationless wave approximation is proposed. The Jaynes-Cummings models of two-level system and three-level system have been investigated. Compared to some other approximate approaches, this approach can give not only an analytic exact solution, which agrees with others results but also a restraint condition, which is usefull for practical experiment.
DESIGN OF SOFT X-RAY MULTILAYERS FOR SHORTER WAVELENGTHS
Authors: SHAO JIAN-DA  , YI KUI  , FAN ZHENG-XIU  , WANG RUN-WEN  , CUI MING-QI  ,   (1)中国科学院高能物理研究所; (2)中国科学院上海光学精密机械研究所
Published: December 2020

This paper discussed a method of designing soft X-ray multilayers for shorter wavelengths and showed that a difference between the designing of longer wavelength soft X-ray multilayers and that of the shorter one.For the latter,the minimum continuous thickness of the metal layer have to be considered.The method of second order designing could be a way to deposit high-quality multilayer mirrors for shorter wavelengths.The measured reflectivity of a Mo/Si multilayer for 4.47nm is also reported.
MATRIX ELEMENTS OF RAISING AND LOWERING OPERATORS OF AN ISOTROPIC HARMONIC OSCILLATOR
Authors: LI GUANG-HUI  ,   湖北省荆州师范高等专科学校物理系
Published: December 2020

A new definition of four kinds of raising and lowering operators of an isotropic harmonic oscillator is given. Their matrix elements and normalizing constants are calculated.
A CONFORMALLY FLAT SOLUTION OF EINSTEIN MAXWELL EQUATIONS FOR A STATIONARY SPHERICALLY SYMMETRIC DISTRIBUTION OF SPHERE POSSESSING BOTH ELECTRIC AND MAGNETIC CHARGES
Authors: ZHANG JING-YI  ,   广东石油化工高等专科学校物理室
Published: December 2020

This paper gives a conformally flat interior solution of Einstein Maxwell equations for a stationary spherically symmetric distribution of sphere possessing both electric and magnetic charges. The solution is physically reasonable.
FREQUENCY CHARACTERISTICS OF THE INPUT THRESHOLDS OF STOCHASTIC RESONANT SYSTEMS
Authors: WANG JIA-FU  , LIU FENG  , WANG JUN-YI  , CHEN GUANG  , WANG WEI  ,   南京大学物理系
Published: December 2020

By simulating the frequency behaviors of the input thresholds in a bistable system and a Hindmarsh Rose neuron, respectively, we study how the input thresholds depend on the frequency of input signal in both non excitable and excitable nonlinear systems in which stochastic resonance may appear. We also present an approximate approach to get the frequency characteristics of input threshold analytically and analyze the unusual minima of the frequency characteristics in excitable systems.
AN EASY WAY FOR CONSTRUCTING FREDKIN QUANTUM GATE
Authors: ZHANG DENG-YU  , ZHAN MING-SHENG  ,   (1)中国科学院安徽光学精密机械研究所激光光谱学开放实验室; (2)中国科学院武汉物理研究所波谱与原子分子物理国家重点实验室
Published: December 2020

We propose a method for constructing Fredkin gate by using basic 2 bit quantum gates,which is based on A.Darenco's work.Compared with H.F.Chau's scheme,this scheme is easier to construct and to understand,as well as to put into practice.
SMALL AMPLITUDE SOLITON SOLUTIONS OF THE COUPLED NONLINEAR SCHR?DINGER EQUATIONS IN BIREFRINGENCE OPTICAL FIBER
Authors: DUAN YI-SHI  , YU ZHONG-YUAN  , WU ZHEN-SEN  ,   (1)兰州大学物理系; (2)西安电子科技大学物理系
Published: December 2020

Small amplitude soliton solutions are obtained which satisfy the coupled nonlinear Schr?dinger equations governing optical pulses propagation in the birefringence optical fiber.
A NEW METHOD FOR CALCULATING BIT ERROR PROBABILITY IN OPTICAL SOLITON COMMUNICATION SYSTEM
Authors: HUANG HU-QING  , LI FEI  ,   南京邮电学院
Published: December 2020

In this paper we use the method of steepest descent (also called saddlepoint method) to evaluate bit-error probability of the ultra-long distance optical soliton communication systems with lumped amplifiers and then compare these results with the Gaussian approximation.
NONLINEAR INTERNAL FRICTION BEHAVIOR IN MnCu ALLOY DURING THERMOELASTIC MARTENSITIC TRANSITION
Authors: LIU JUN-MIN  ,   中山大学物理系
Published: December 2020

With forced-mode measurements,the dependence of internal friction on the rate of change of temperature and vibration frequency in MnCu alloy undergoing thermoelastic martensitic phase-transition was investigated.Based on the results of the experiment a new empirical relationship was proposed-.
A MOLECULAR DYNAMICS STUDY OF SELF-DIFFUSION ON Ag(100) SURFACE
Authors: ZHUANG JUN  , LIU LEI  ,   复旦大学物理系
Published: December 2020

Self-diffusion of Ag/Ag (100) is investigated by molecular dynamics with the semiempirical surface-embedded-atom method (SEAM) potential. Many diffusion mechanisms, such as hopping, simple exchange, complicated exchange and a new mechanism named multiple-hopping are observed. Another model for explaining the complicated exchange mechanism is given. From Arrhenius- behavior of the adatom and the statistical results, we obtain the active energies for simple- exchange and hopping mechanisms respectively, they are 0.39 and 0.47eV.
M?SSBAUER SPECTROSCOPY STUDY OF NiFe2O4 NANOSOLID COMPACTED UNDER HIGH PRESSURE
Authors: SUI YU  , SU WEN-HUI  , ZHENG FAN-LEI  , XU DA-PENG  ,   (1)吉林大学物理系; (2)吉林大学物理系;中国科学院国际材料物理中心;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; (3)吉林大学物理系;中国科学院金属研究所
Published: December 2020

NiFe2O4 nanoparticles with on average grain size of 12nm were compacted into nanosolids under the pressure of 0.0—4.5GPa.The M?ssbauer spectra of NiFe2O4 nanosolids at room temperature and low temperatures show that high pressure has a strong influence on the magnetic interaction and interface atomic state inside the nanosolid,though the crystal structure and average grain size of nanosolid do not change under high pressure.Under high pressure,the superparamagnetic relaxation of NiFe2O4 nanosolid is suppressed obviously by the enhancement of the interparticle magnetic dipole interaction and the superexchange interaction among the interface ions in the nanosolid,and the magnetic anisotropy of it is also weakened by the interparticle magnetic coupling in it.At the same time,the symmetry and the degree of short-range order of the polyhedrons are raised gradually with the increase of pressure,and then the atomic structure in the surface and interface zone of NiFe2O4 nanosolid shows a tendency to change into the grain boundary structure of common polycrystalline solid with large grain size.
HAMILTONIAN OPERATORS CONSTRUCTED FROM TWO KINDS OF FINITE-DEPTH QUANTUM POTENTIAL WELLS WITH TIME-DEPENDENT BOUNDARY CONDITIONS AND THEIR COMPLEX BERRY PHASES
Authors: ZHANG RUN-DONG  , YAN FENG-LI  , LI BO-ZANG  ,   (1)河北师范大学物理系，石家庄  050016; (2)中国科学院物理研究所和凝聚态物理中心，北京  100080
Published: December 2020

In the frame of the basic quantum theory,from the one-dimensional infinite-height half-wall quantum potential well with time-dependent boundary conditions and from the three-dimensional finite-depth sphere-square potential well with time-dependent boundary conditions we constructed two kinds of new Hamiltonian operators separately which describe electric particle interacting with eletromagnetic field.In the adiabatic approximation are calculated the complex Berry phases of two kinds of new systems.
THE MICROSCOPIC MECHANISM OF ALLOYING ELEMENTS AFFECTING THE DUCTILITY OR BRITTLENESS OF FeAl INTERMETALLICS
Authors: ZHONG XIA-PING  , DENG WEN  , TANG YU-SHENG  , XIONG LIANG-YUE  , WANG SHU-HE  , GUO JIAN-TING  , LONG QI-WEI  ,   (1)广西大学物理系，南宁  530004; (2)广西大学物理系，南宁  530004;中国科学院国际材料物理中心，沈阳  110015; (3)玉林教育学院物理系，玉林  537000; (4)中国科学院国际材料物理中心，沈阳  110015;中国科学院金属研究所，沈阳  110015
Published: December 2020

The valence electron densities of bulk and microdefects in binary FeAl, and FeAl doping with B,Zr or Si have been calculated by using the positron lifetime parameters of the alloys. The density of valence electron is low in the bulk of FeAl alloy. It indicates that, in Fe atom the 3d electrons have well-localized properties and tend to form covalent bonds with Al atoms, thus the bonding nature in FeAl is a mixture of metallic and covalent. The large-open-volume defects occur in grain boundaries in FeAl and the cohesion of the grain boundaries is weak due to the low density of valence electron there. When a small amount of B atoms is added into FeAl alloy, some of B atoms segregate to the grain boundaries and increase the valence electron density; this will strengthen the bonding cohesion in the grain boundaries. The other B atoms are dissolved interstitially into the bulk, they interact with Fe and Al, increase the density of valence electrons and thus the bonding cohesion in the bulk. The addition of Zr into FeAl results in the increase of the density of valence electrons in the bulk and grain boundary. Whereas, if FeAl is alloyed with Si, the density of valence electrons in the grain boundary will decrease. B and Zr are found to be beneficial elements for improving the brittleness of FeAl alloy, while Si exhibits an opposite effect.
NUMERICAL ANALYSIS OF LIGHT SCATTERING BY RANDOMLY ORIENTED CUBIC PARTICLES
Authors: RAO RUI-ZHONG  ,   中国科学院安徽光学精密机械研究所，合肥 230031
Published: December 2020

Numerical calculations were carried out on light scattering by randomly oriented cubic particles for several size parameters. The scattering properties were analyzed and compared with those of the equivalent spherical particles. Results show that the differences between the scattering properties of cubic and spherical particles are similar to those between other non-spherical and spherical particles. The results imply the intrinsic symmetry and discontinuity of the normal direction of the particle surface have little effects on the scattering properties.
PHASE EIAGRAM OF ONE-DIMENSIONAL BOSONS IN AN ARRAY OF LOCAL POTENTIALS
Authors: SHI YUN-LONG  , ZHANG YU-MEI  , CHEN HONG  , WU XIANG  ,   (1)同济大学物理系，大海 200092; (2)雁北师范学院物理系,大同 037000；同济大学物理系，大海 200092
Published: December 2020

The Gaussian wave functional method is applied to a boson system with an array of local potentials cos［β（ｎR）］to study the phase transition of its ground of its ground state. The stable ground state is determined by the parameter γ＝β2/4π and the renormalized mass μ．In different regions, μ can have different multiplicity, the phase diagram is thus depicted. The phase boundary γ＝γ1 depends on the concentration c; for c←0, it coincides with that of the single impurity model, while for γ=2 it coincides with the conclusion of the continuous model.
LARMOR CLOCK IN ONE-DIMENSIONAL COMBINED POTENTIAL
Authors: YUAN ZHUO-QUAN  , MA ZHONG-SUI  , LI HUA-ZHONG  ,   (1)中山大学高等学术研究中心，广州 510275; (2)中山大学物理系，广州 510275
Published: December 2020

In this paper, with the use of Larmor clock, the tunneling times of one-dimensional combined potential are calculated. According to the results, the characters of Larmor times which are defined by Larmor clock method are discussed. It was found that the equality τyT=τyR=τD does not hold in general. Whether the equality τyT=τyR holds is determined by the symmetry of the potential. The Larmor times τyT and τyR may offer definition for transmitted time τT and reflected time τR, but τxT,τxR,τyT and τyR cannot. In addition, τyT and τyR can satisfy the equality τD=TτyT+RτyR.
AGGREGATION CHARACTERISTICS OF SILVER ATOMS DEPOSITED ON LIQUID SUBSTRATES
Authors: YE GAO-XIANG  , YANG BO  , XIA A-GEN  , JIN JIN-SHENG  , LUO MENG-BO  , XU JIAN-MIN  ,   杭州大学物理系，杭州 310028
Published: December 2020

The diffusion and aggregation characteristics of silver atoms deposited on liquid substrates are studied. Experimental results indicate that the silver atoms first form compact clusters. Then the clusters diffuse and aggregate on the liquid surfaces. Finally they shape into ramified aggregate. We find that both the average radius of the compact clusters and the aggregation rate depend on the deposition rate. An aggregation rate possibility model is established and the theoretical result is in good agreement with the experimental data.
EXTENTED PAINLEV? EXPANSION AND NONSTANDARD TRUNCATION SOLUTIONS OF THE KdV EQUATION
Authors: LOU SEN-YUE  ,   宁波大学数学物理研究所,宁波  315211
Published: December 2020

In this paper,by means of the arbitrariness of the singularity,we have established a new approach of the Painlevé analysis developed by Weiss,Tabor and Carnevale,which is one of the powerful method to study the nonlinear partial differential equations.Selecting some different expansion functions and nonstandard truncations for the KdV equation,we obtained many exact solutions expressed by some complicated implicit functions.
q-PHASE-COHERENT STATES AND THEIR SQUEEZING PROPERTIES
Authors: LIN ZHI-XIN  , YANG YA-PING  , FENG WEI-GUO  ,   中国高等科学技术中心(世界实验室)，北京8730信箱，北京  100080;同济大学物理系，上海  200092
Published: December 2020

Squeezing properties of q-phase-coherent states with respect to the phase quadrature operators are studied.The relations between number-phase squeezing and number-phase uncertainty are also studied in detail for a two-state system.Some new number-phase minimum uncertainty states are found.
THE EFFECTS OF CHARGED PARTICLE SYSTEM'S ENERGY LEVEL SEPERATION IN MAGNETIC FIELD
Authors: NIE SHI-QI  , LIN SHU-QUAN  , HUANG BAO-LIN  ,   上海交通大学HDTV研究所，上海  200030
Published: December 2020

In this paper, the charged particle systems energy level seperation in the vertical direction of the magnetic field is considered, according to Boltzmann distribution. Several equations are obtained. The effects are obvious under the condition of low temperature and high intensity magnetic field. Several equations of plasma MHD are corrected.
OPTICAL MICROSCOPIC STUDY OF THE INFLUENCE OF DIFFERENT ELECTRODES ON THE IONIC TRANSPORT CHARACTER OF α-LiIO3
Authors: LIU JIAN  , GAO ZHONG-CHENG  , ZHANG CHUN-PING  , TIAN JIAN-GUO  , ZHANG GUANG-YIN  ,   南开大学物理系，天津  300071
Published: December 2020

This paper presents an account of our observation on characters of the α-LiIO3 by using a plorazation microscope. The conduction of crystal,the deposition and distribution of the space charges were studied for eight crystal specimens under the actions of the DC electric field in c-direction with five different electrode interface states. The colored quasi-straight bright lines were observed that formed through the transport of the space electric charges of α-LiIO3.There are a correspondence relation between it and the diffraction band of the photo-refractive grating in the crystals, and the different interface states have exerted obvious influence on the ionic transport and crystal conduction in α-LiIO3.
Behavior of Core Loss in Nanocrystalline Fe73.5Cu1Nb3Si13.5B9 Alloy with High Br
Authors: Zhang Yan-Zhong  , Jin Hui-Juan  , Shi Ying  ,   上海钢铁研究所，上海金属功能材料研究所和开发重点实验室，上海 200940
Published: December 2020

In the ranges of f=1020000Hz and Bm=0.11.0T, the core loss has been measured for nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloy with high Br. The total power loss was decomposed into the sum of the classical eddy current loss, the hysteresis loss and the excess loss. The results show that the change of the total loss per cycle with frequency clearly shows a nonlinear behavior, which has been described in terms of Bertotti's statistical theory of loss. The frequency range examined can nearly be divided into two intervals, in which there exist two different describing ways.
Magneto-Optic Properties of Pt/Co/Pt/Ni Multilayers
Authors: Wang Hai  , Zhou Yun-Song  , Wang Ai-Ling  , Zheng Wu  , Chen Jin-Chang  ,   首都师范大学物理系，北京 100037
Published: December 2020

A series of Pt/Co/Pt/Ni modulated multilayer with Ni layer thickness tNi ranging from 0 to 2.4nm have been prepared by magnetron sputtering on Pt buffer. The relations between conductivity tensors σ1xx,σ2xx,σ1xy,σ2xy and tNi were calculated with measured values of Kerr rotation, ellipticity, refractive index and absorption index. And then, θK =θK [σ1xx(tNi,σ2xx(tNi),σ1xy(tNi),σ2xy(tNi)] as a compound function of tNi was calculated. It exhibits that, with the change of tNi, σ2xy is the major factor to influnce θK at short wave length and all of the four conductivity tensors are important at long wavelength, no one is negligible. We think that the splitting of Pt 5d band, which originates from spin-orbit coupling, decreases with the increase of tNi. The Curie temperature TC decreases monotonically with increasing tNi. For purpose of application, we show a range of tNi (0.3—1.0nm), in which TC is lower while θK and R is higher than pure Pt/Co multilayers.
MULTIFRACTAL OF THE FAILURE PEROCESS OF ELECTROLUMINSCENCE OF ORGANIC THIN FILM
Authors: WANG XIAO-PING  , ZHOU XIANG  , HE JUN  , LIAO LIANG-SHENG  , WU ZI-QIN  ,   (1)复旦大学应用表面物理国家重点实验室，上海  200433; (2)中国科学技术大学天文和应用物理系，合肥  230026; (3)中国科学技术大学物理系，合肥  230026
Published: December 2020

The multifractal approach was used to describe the failure process of organic thin film electrolu-minescence observed with fluomicroscope dynamically.It was found that the failure of the electrolu-minescence resulted from the bubbles generated at the interface between the organic layper and the metal electrode.The bubbles became more and more numerous during the device working.Multifrac-tal spectra showed that the longer the working time or the higher the loaded voltage of the device,the narrower the spectrum.This result was in good agreement with the experimental observation.
TRANSITIVITY OF CLOCK RATE SYNCHRONIZATION BEING EQUIVALENT TO THE ZEROTH LAW OF THERMODYNAMICS
Authors: ZHAO ZHENG  , PEI SHOU-YONG  , LIU LIAO  ,   北京师范大学物理系，北京  100875
Published: December 2020

The equilibrium thermal radiation in a flat space-time or a curved space-time behaves like Planck black spectrum represented with coordinate quantities.We regard the fact that the radiation from a thermal equilibrium system shows Planck black spectrum as a basic physics law,from which it is demonstrated that the transitivity of clock rate synchronization is equivalent to the zeroth law of thermodynamics.The condition of clock rate synchronization is weaker than that constructing simultaneity surfaces.In the space-time satisfying the condition of clock rate synchronization,the zeroth law of thermodynamics is valid.On the other hand,in the space-time where the zeroth law is valid,one can define an identical clock rate.
NONLINEAR OPTICAL PROPERTIES OF THE SUBSTITU-TIONAL FULLERENE C77X(X=B,N ATOMS)
Authors: ZHU JIAN-QI  , DONG JIN-MING  , WAN XIAN-GANG  ,   (1)江苏教育学院物理系，南京  210013; (2)南京大学固体微结构物理国家重点实验室，物理系，南京  210093
Published: December 2020

Using the extened Su-Schrieffer-Heeger model and the Sum-Over-State method, we have calculated the third-order nonlinear polarizability γ and its dispersion spectra for single substitutional fullerenes C77X(X=B or N atoms). The results indicate:(1) compared with C78,each of the static values of γ through the substitutional doping increases to some extent (3—40 times);(2) the dynamic nonliear optical reponse of C77X not only depends on doping atoms, but also depends on the substituted isomers and doped sites.
ATOMIC DIPOLE SQUEEZING AND COHERENT POPULATION TRAPPING IN THE SYSTEM OF TWO-MODE SQUEEZED VACUUM FIELD INTERACTING WITH A TWO-LEVEL ATOM
Authors: TIAN YONG-HONG  , PENG JIN-SHENG  ,   (1)华中师范大学物理系，武汉  430070; (2)华中师范大学物理系，武汉  430070；荆州师范学院物理系，荆州  434100
Published: December 2020

The atomic quantum behaviors in the system of two-mode squeezed vacuum field interacting with a two-level atom via two-photon process are studied by means of quantum theory.The condition for the occurrence of coherent trapping and the influence of the squeezing parameters on the atomic dipole squeezing are discussed.
SPATIAL SOLITONS IN PHOTOVOLTAIC PHOTOREFRACTIVE CRYSTALS IN AN EXTERNAL BIAS FIELD
Authors: LU KE-QING  , TANG TIAN-TONG  ,   西安交通大学电子与信息工程学院，西安  710049
Published: December 2020

Bright and dark spatial solitons are predicted for biased photovoltaic photorefractive crystals, which are due to both the spatially nonuniform screening of the external electric field and the photovoltaic effect. These solitons differ form previously observed photorefractive spatial solitons in their properties. When external electric field is of a certain value, these solitons may be switched from bright to dark both by changing the polarity of the external electric field and by rotating the polarization of the light. In case the effect of the external bias field is much stronger than the photovoltaic effect and the latter can be neglected, these solitons are similar to screening solitons. In case the external bias field is absent, these solitons are similar to photovoltaic solitons in the open-circuit case.
Magnetization Reveral Behavior and Magnetic Viscosity of Nanocomposite Nd3.6Pr5.4Fe83Co3B5
Authors: Zhang Hong-Wei  , Zhang Wen-Yong  , Yan A-Ru  , Shen Bao-Gen  ,   中国科学院物理研究所与凝聚态物理中心磁学国家重点实验室,北京 100080
Published: December 2020

Nanocomposite Nd3.6Pr5.4Fe83Co3B5 ribbons were prepared by direct melt spining at wheel speed of 20m/s. Although Nd2Fe14B-type phase and α-Fe were found in the ribbons, a single hard magnetic behavior with high coercivity can only be found in the hysteresis loop. The recoil curves show a comparatively high degree of reversibility in the fields below coercivity. From the investigations of reversible and irreversible portions in DC demagnetization remanence curve, the irreversible nucleation field of about 440 kA/m has been obtained in melt-spun Nd3.6Pr5.4Fe83Co3B5 ribbons. The measurements of magnetic viscosity show that the time-dependent magnetization changes are associated with reversal of the hard phase. The thermal fluctuation field of about 2.0kA/m was obtained.
THE FORMATION AND PROPAGATION OF DOMAINS IN SUPERLATTICES DISCUSSED WITH NONLINEAR SCHR¨ODINGER EQUATION
Authors: TIAN QIANG  , MA BEN-KUN  ,   北京师范大学物理系，北京  100875
Published: December 2020

The formation and propagation of domains in superlattices are discussed using a nonlinear Schrdinger equation.Negative differential conductivity in superlattices leads to the growth of inevitable spatial fluctuations,and a propagating electron accumulation-layer domain is formed.It is shown that envelopes of the wave functions are governed by the nonlinear Schrdinger equation which has soliton solutions.
MAGNETOCALORIC EFFECT OF La0.75Ca0.25-xSrxMnO3 PEROVSKITE
Authors: SHEN YA-TAO  , GUO ZAI-BING  , DU YOU-WEI  ,   南京大学物理系，固体微结构物理国家重点实验室，南京  210093
Published: December 2020

A series of polycrystal samples of La0.75Ca0.25-xSrxMnO3(x=0,0.075,0.1，0.125，0.14，0.15，0.175，0.2，0.25)was prepared.The entropy change and Curie temperature were measured under a magnetic field 1.5T.The microstructure of samples was used to explain the change of properties as Sr2+ substituted for Ca2+.Amalgamating a few of samples made the compound material suitable to employ Ericsson cycle.
The Study of the Structural, Magnetic and Magneto-Optical Properties of (Pt3Co)1-xNix Alloy Films
Authors: Zhou Jian  , Xun Kun  , Shen De-Fang  , Xia Guo-Qiang  , Zheng Yu-Xiang  , Chen Liang-Yao  ,   (1)复旦大学物理系，上海 200433; (2)中国科学院上海冶金研究所，上海 200050
Published: December 2020

The ratio of non-magnetic to magnetic atoms was adjusted from 3:1 to 1:1 within the (Pt3Co)1-xNix system by sticking Ni chips to the Pt3Co target. X-ray diffraction and magnetic results showed that perpendicular magnetic anisotropy was not caused by texture at least in the Ni content range of 0.33—0.50. Furthermore, the effect of the Ni addition to the CoPt3 alloy films on their magnetic and magneto-optical propertical were investigated. The result shows that satisfactory Curie temperature TC, cohercivity Hc and Kerr rotation can be simultaneously obtained by selecting suitable Ni content (x=0.43) in the (Pt3Co)1-xNix system. This work provides an experimental basis for the application of PtCoNi alloy films.
CRISES WITH SPECIAL SCALING PROPERTIES IN PEICE-WISE-SMOOTH SYSTEMS
Authors: WU SHUN-GUANG  , DING XIAO-LING  , HE DA-REN  ,   (1)北京师范大学低能核物理研究所，北京  100875; (2)扬州大学理学院物理系，扬州  225002
Published: December 2020

Two kinds of crises with speciality properties in piece-wise-smooth systems are reported. The crises are induced by the discontinuity of the systems. The mechanism of the first kind of crisis is a collision between a forbiden region and an unstable orbit located in the region of chaotic attractor. On the contrary, the second one is produced by the collision between a chaotic attractor and a hole induced by the discontinuous regions of the system. For the first one, the scaling laws of the average laminar lenths and its distribution are 〈τ〉∝-1.8 and P(τ)=1〈τ〉exp-τ/〈τ〉, respectively. Meanwhile, for the second one, the scaling laws are 〈τ〉∝exp(k-1/2) and P(τ)=1〈τ〉·exp-τ/〈τ〉).
The Texture and Topography of Melt-Spun Ribbons of Nd2Fe14B/α-Fe Two-Phase Permanent Magnetic Alloys
Authors: Zhang Min-Gang  , Chai Yue-Sheng  , Kokawa Ryohei  , Zheng Jian-Jun  , Jin Zhi-Hao  ,   (1)日本岛津表面、半导体机器部，日本 秦野; (2)太原重型机械学院材料工程系，太原 030024; (3)西安交通大学金属材料强度国家重点实验室，西安 710049; (4)西安交通大学金属材料强度国家重点实验室，西安 710049；太原重型机械学院材料工程系，太原 030024
Published: December 2020

The texture and topography of melt-spun ribbons of nanocrystalline two-phase permanent magnetic alloys was studied by X-ray diffractometry and scanning probe microscopy. It was found that a pronounced preferred orientation existed in the free-side surface of melt-spun ribbons. Compared with ternary NdFeB alloy, adding Dy+Ga can increase the texture in free-side surface and refine the microstructure and topography of the ribbons.
MOLECULAR DYNAMICS STUDY ON LOCAL STRUCTURE OF MOLTEN SILICON
Authors: ZHOU ZHEN-YOU  , WANG TIE-BING  , CHENG ZHAO-NIAN  ,   中国科学院上海冶金研究所，上海  200050
Published: December 2020

A modified Tersoff potential developed by extending atomic interaction distancehas been applied to simulating the properties of liquid silicon with molecular dynamics. The radical distribution functions with coordination number 6.9 and bond length 0.254nm from the simulation are in good agreement with the experimental results from X-ray diffraction and neutron scattering. The configurations simulated indicate that a chain-network structure is formed among silicon atoms in liquid silicon,and a majority of atoms remain tetrahedral local structure with near-neighbour atoms. The presence of two peaks,~57° and ~102°,in bond angle probability distribution indicates a very complicated structure in liquid silicon. Based on the instantaneous configurations given by the simulation,the local structures in liquid states have been studied with bond-order parameter method. The results show there are ~82% tetrahedron structures in the near-neighbour structures in liquid state and the square deviation of bond-orientational luctuation is about 5.2°. The results also show that except thericosahedron structure,the non-tetrahedral structures may include some other near-neighbour structures.