bluuebunny/crossref_metadata_2025 huggingface dataset:
INVESTIGATION ON NON-EQUILIBRIUM X-RAY EMISSION SPECTRA FROM LASER PRODUCED PLASMAS
Authors: PEI WEN-BING  , CHANG TIE-QIANG  , ZHANG JUN  ,   北京应用物理与计算数学研究所,北京100088
Published: December 2020

A statistical method for the ion configuration probability distribution in non-LTE plasmas based on the average-ion model is described. In this method, the ion configuration probabilities are obtained from the average level population probabilities of the ions according to the binomial distribution. The non-equilibrium ion configuration distribution and X-ray spectra emitted from Au plasmas produced by 1.06 μm laser are studied. The calculated X-ray emission spectra are in the same energy band range as the experimental results. We discuss the non-equilibrium characteristics of X-ray emission, and show that the contributions of the multiply excited ions to X-ray emission are important.
QUANTUM CHEMISTRY CALCULATIONS ON THE LATTICE INSTABILITIES OF HEXAHALOMET- ALLATES
Authors: ZHANG JIA-MING  , LU WEI  , SHEN XUE-CHU  ,   中国科学院上海技术物理研究所红外物理国家重点实验室,上海200083
Published: December 2020

The calculation method of quantum chemistry has been extended to describe the lattice instabilities and the nature of the lattice instabilities of hexahalometallates. Some interesting calculation results have been obtained and compared with the exper-imental results obtained by Raman and Brillouin scattering.
H2 DISSOCIATIVE ADSORPTION ON SURFACES OF Ni, Pd and Cu
Authors: SUN QIANG  , XIE JIAN-JUN  , ZHANG TAO  ,   (1)复旦大学物理系,上海200433; (2)河南省科学技术协会,郑州450003; (3)郑州大学物理系,郑州450052
Published: December 2020

The dissociative adsorption of hydrogen molecule on (100), (110) and (111) surfaces of Ni, Pd and Cu are investigated using the embeded-atom method (EAM). First, the EAM potentials for H-metal surfaces are obtained by fitting the adsorption energies and the length of adsorption bond for single H atom on different surfaces of Ni, Pd and Cu. Then, the activation barriers Ea, adsorption heat q2d and corresponding H-metal bond length R for dissociation of H2 through various pathways are calculated. The potential energy contours for H2 dissociation on (110) surfaces of different metals are presented. The calculated results show that the dissociative adsorption of a hydrogen molecule depend on the species of substrate, the surface orientation and the dissociative pathways. The activation barrier for H2 dissociation on Nisurface is very low, while it is higher for H2 dissociation on Cu surface. The dissociative adsorption of H2 is easier on open (110) surface than that on close-packed(111) surfaces. Among the discussed dissociation pathways, it appears that the most favourable pathway for H2 is that from bridge site to the adjacent centre sites.
AN EXPERIMENTAL SIMULATION ON LARGE-SCALE HELITON
Authors: ZHAO SONG-NIAN  , XIONG XIAO-YUN  , ZHU JIANG  ,   中国科学院大气物理研究所
Published: December 2020

Large-scale vortex motion, the typical example of which is typhoon in nature, has behaviour of soliton. This is proved by large-scale dynamical simulation experiment in the rotating annulus. Thus we suggest that one can adopt scientific term "Heliton"(i.e.,helical soliton) to characterize this motion pattern.
STEADY-STATE BEAM FANNING IN PHOTOREFRACTIVE CRYSTALS
Authors: GUO RU  , PAN SHI-HONG  , ZHANG GUANG-YIN  ,   南开大学物理系
Published: December 2020

It is shown that multiwave mixing of the beam itself in high-gain photorefractive crystals is also a possible cause of beam fanning. Through the multiwave coupling of the beam itself the power can asymmetrically transfer from low to high spatial frequencies. This leads to a broad-angled profile of light. Thus amplified noise and amplified spatial frequencies of the beam both play an important role in producing the fanning effect.
SELF-PUMPED PHASE CONJUGATION OF IMPERFECTLY MODE-LOCKED PICOSECOND LASER PULSES INDUCED BY A PHOTOREFRACTIVE WAVEGUIDE
Authors: SHE WEI-LONG  , YU ZHEN-XIN  , LEE WING KEE  ,   (1)香港中文大学物理系; (2)中山大学超快速激光光谱学国家重点实验室
Published: December 2020

Normally, when an imperfectly mode-locked 532nm ps laser is incident upon a Cu:KNSBN photorefractive crystal, no self-pumped phase conjugation can occur. We report however, for the first time to our knowledge, that if a photorefractive waveguide is first created in the crystal by a mode-locked beam of the same wavelength, then self-pumped phase conjugation can be induced for the imperfectly mode-locked beam.
INVESTIGATION OF THE TEMPERATURE DEPENDENCE OF SURFACE ANCHORING ENERGY FOR LIQUID CRYSTALS
Authors: SUN RUI-PENG  , HUANG XI-MIN  , SHAO XI-BIN  , MA KAI  , JING HAI  ,   中国科学院长春物理研究所
Published: December 2020

The surface anchoring of nematic liquid crystals is an important coefficient which expresses the effect of liquid crystal alignment and the mechanism of the surface alignment. The surface azimuthal anchoring energy can be obtained by measuring the twist angle in the twist cell and the surface torsional angle between the rubbing direction and the liquid crystal director at the substrate boundary. The temperature dependence of the surface anchoring energy at 5CB-polyimide (PI) interface was studied. The surface anchoring energy decreases with increase of the temperature from ５.０×１０－5Ｊ／ｍ2 at 25.５℃ to ５.０×１０－6Ｊ／ｍ2 at 35.0℃. Meanwhile, the extrapolation length ｄe increases from 80nm at 25.5℃ to ３７０ｎｍ at ０.５℃ below Ｔc. This result clearly signifies the important role of the ordered structure of the nematic interface in determining the temperature dependence of the anchoring strength at the ５ＣＢ-PI interface.
STUDY OF SURFACE ANCHORING OF LIQUID CRYSTALS ON POLYIMIDE LB FILMS
Authors: SUN RUI-PENG  , GUO JIAN-XIN  , WANG ZONG-KAI  , MA KAI  , HUANG XI-MIN  ,   中国科学院长春物理研究所
Published: December 2020

The surface alignment of liquid crystals is very important in preparing liquid crystal cells. The orientational effect of liquid crystal and polymide molecules on Langmuir-Blodgett(LB) films has been studied. The degree of orientation of the polyimide chain in LB films is weaker than that in strong rubbing films. The orientational effect of liquid crystals on the polyimide LB films is worse than that on the strong rubbing films. The surface azimuthal anchoring energy of liquid crystals on the polyimide LB films was measured. The intermolecular interaction between liquid crystal and polymer molecules is considered to be very important for the alignment of liquid crystals on the polymer surface.
NONLINEAR EXCITATIONS IN ONE DIMENSIONAL HEISENBERG FERROMAGNETIC CHAIN WITH BOND ALTERNATION
Authors: ZHU SHAN-HUA  , HUANG GUO-XIANG  , XU ZAI-XIN  ,   (1)华东师范大学物理系; (2)株洲工学院物理教研室;华东师范大学物理系
Published: December 2020

About the one-dimensional Heisenberg ferromagnetics chain with bond alternation,research results show,in first-order approximation,that (1) magnon gap solitons (with the vibrating frequency lying in the gap between magnon frequency band) and resonant kinks (with the vibrating frequency lying in the magnon frequency band) are found; (2) an instrinsic localized mode (with the vibrating frequency being above the magnon frequency band) is impossible.
PREDISSOCIATION OF HYDROGEN IN THE-3pπ D1πu+ AND 4pσ B″1Σu+ STATES
Authors: GAO HONG  ,   清华大学现代应用物理系单原子分子测控科学与技术中心
Published: December 2020

The predissociation of H 2 in its Rydberg states has been studied using the multichannel quantum defect theory,combined with the frame transformation and the non iterative eigenchannel R matrix method.The predissociation line positions and the widths are calculated for 3pπ 1πu+(v=3,J=1,2) and 4pσ B″1Σu+(v=2,J=1,2) levels.The predissociation mechanisms are discussed.
STUDY OF SOLITON SOLUTIONS OF A CLASS OF GENERALIZED NONLINEAR SCHR?DINGER EQUATIONS IN N-SPACE
Authors: CAO QING-JIE  , ZHANG TIAN-DE  , LI JIU-PING  , G.W.PRICE  , K.DJIDJELI  , E.H.TWIZELL  ,   (1)Department of Mathematics and Statistics,Brunel University,Uxbridge,Middlesex UB8 3PH,UK; (2)Department of Ship Science,University of Southampton,Southampton SO17 1BJ,UK; (3)山东工业大学数理系
Published: December 2020

Soliton solutions and the properties of a class of generalized nonlinear Schr?dinger (GNLS) equations in N-space are discussed analytically and numerically. The discussion has been done by using a travelling wave method to get one soliton solution and the finite difference method to get the numerical solutions for the GNLS equations. The states of the soliton solutions of the system admitting nonlinearity have been investigated when α→0 and α→∞.The P-R scheme for the system has been studied, and the conditions of stability and convergence for the scheme were obtained.
MECHANISM OF MICROWAVE GENERATION IN SUPER-RELTRON
Authors: DING WU  ,   北京应用物理与计算数学研究所
Published: December 2020

In this paper, a physical description of the mechanism of microwave generation in Super-Reltron is presented, and the analytical formulas of the beam bunching in the modulation cavity and the prebunching beam emitted in the radiation cavity are derived.
A NEW TECHNIQUE FOR OBTAINING THE “MOBILITIES SPECTRUM” TRANSIENT THERMOELECTRIC EFFECT
Authors: GAO WEN-XIU  , HUANG MEI-CHUN  , CHEN CHUAN-HONG  , YANG ZU-SHEN  ,   (1)厦门大学物理系; (2)新疆大学物理系
Published: December 2020

We introduced a new technique called “Transient Thermoelectric Effect (TTE)”, which was based on carrier-diffusion as irradiated by a pulsed laser. The observed TTE voltages decayed exponentially with time, showing a multi-relaxation process with characteristic relaxation times τi(i=1,2,3,…) for thermal diffusions of photo-induced conduction carriers, analyses of these results could give valuable information about carrier mobilities, effective masses and Fermi surfaces. The principle and the main analysis method were also described in detail.
DYNAMIC BEHAVIOR OF SUPERCURRENT IN MESOSCOPIC JOSEPHSON JUNCTION INTERACTING WITH CORRELATED TWO MODE SU(1,1) COHERENT STATES OF QUANTUM ELECTROMAGNETIC FIELD
Authors: ZOU JIAN  , SHAO BIN  , XING XIU-SAN  ,   北京理工大学应用物理系
Published: December 2020

The dynamic behaviors of supercurrent in mesoscopic Josephson junction in the presence of a dc bias voltage V0-and of correlated two-mode SU(1,1) coherent states of quantum electromagnetic field, as well as current-voltage steps and Shapiro dc current, are investigated.It is shown that the time evolution of supercurrent exhibits collapse and revival phenomenon, but for non-correlated two-mode coherent states it does not exhibit such a phenomenon. And the current-voltage steps of correlated two-mode SU(1,1) coherent states of quantum electromagnetic field are different from that of classical electromagnetic field and that of non correlated two-mode coherent states.
TRANSVERSE DIFFRACTION EFFECTS OF LIGHT FIELDS ON THE GAIN WITHOUT POPULATION INVERSION
Authors: ZHANG HAN-ZHUANG  , GAO JIN-YUE  ,   吉林大学物理系
Published: December 2020

We discussed transverse diffraction effects of probe and driving fields on the gain in the model of Raman driven four level atomic system. The calculated results showed that the spectrum of the probe field has different structure compared with that in plane wave approximation due to the transverse diffraction effects of light fields, and the optimum focal position of a focus lens for the maximum gain is in the vicinity of a sample cell.
COHESIVE ENERGIES AND ELECTRONIC STRUCTURES OF Co3Ti AND CoTi
Authors: DUAN SU-QING  , LIU SHAO-JUN  , MA BEN-KUN  ,   北京师范大学物理系
Published: December 2020

Electronic structure calculations using the tight-binding linear muffin-tin orbital (TB-LMTO) method have been performed for two cobalt titanides, viz. Co3Ti and CoTi. The ab initio curves of cohesive energies vs lattice constants and density of states(DOS) have been obtained. The lattice constants and bulk moduli are in good agreement with the experimental values.
ELECTRON IMPACT WITH ARGON EXCITATION OUT OF THE e-Ar(3p54s,J=2)
Authors: JIN SHI-QI  , XU ZHI-ZHAN  ,   中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

It is shown that the electron impact with argon excitation out of the metastable to the 3p54p levels is very important for spectrum,laser physics and plasma processing.Analysis of the cross sections of 3p54p,J=3 level in mainfolds of 3p54p is valuable.It also provides the atomic character of emission harmonics in intense laser field.
PHOTON NOISE SQUEEZING AND ITS PHYSICAL MECHANISM OF A DRIVEN V-TYPE THREE-LEVEL LASER
Authors: HU XIANG-MING  , PENG JIN-SHENG  ,   (1)华中师范大学物理系，武汉  430079; (2)华中师范大学物理系，武汉  430079;华中师范大学应用物理研究所，武汉  430079
Published: December 2020

Photon noise squeezing and its physical mechanism of a driven V-type three-level laser are investigated via Scully-Lamb theory.It is shown that intracavity squeezing of 10% and extracavity squeezing of 20% can be achieved.Even if the amount of squeezing in V system is smaller than that in Λ system (intracavity squeezing and extracavity squeezing of up to 50%),both systems have the same mechanism responsible for the squeezing of photon noise.
STUDY OF THE PHOTON ECHO IN UMSCTS
Authors: ZHANG YAN-PENG  , ZHU JING-PING  , TANG TIAN-TONG  , FU PAN-MING  ,   (1)西安交通大学电信学院光电子与物理电子工程系，西安  710049; (2)中国科学院物理研究所，北京  100080
Published: December 2020

We have studied the photon echo in ultrafast modulation spectroscopy in a cascade three-level system (UMSCTS).When the pump beams have broadband linewidth,the one-photon and two-photon four-wave mixings are related to the three-pulse stimulated photon echo and sum-frenquency three-level echo when τ＞0,respectively;while the result should coincide with the case that the beams have narrow linewidth when τ＜0.
PREPARATION AND SPECTRAL CHARACTERIZATION STUDIES OF FERROELECTRIC ULTRAFINE PARTICLES/STEARIC ACID LB FILM
Authors: LIU CHENG-LIN  , ZHONG JU-HUA  , LI YUAN-GUANG  , ZHANG ZHAO-KUI  ,   (1)华东理工大学物理系，上海  200237; (2)盐城师范专科学校物理系，盐城  224002
Published: December 2020

Ferroelectric ultrafine particles were fabricated with LB film technique. The experimental results showed: The ferroelectric ultrafine particles were stable with a higher coverage ratio, and had a dielectric confinement effect in the LB films. The LB film showed photoluminescence at room temperature. The fluorescence spectrum consisted of wide luminescence bands. The emission spectrum had up-conversion.
ANALYSIS OF 3D TRANSFER FUNCTIONS OF OPTICAL COHERENCE TOMOGRAPHY
Authors: XIANG JI-YING  , WU ZHEN  , ZENG SHAO-QUN  , LUO QING-MING  , ZHANG PING  , HUANG DE-XIU  ,   (1)华中理工大学光电子系，武汉  430074; (2)华中理工大学生物医学光子学研究所激光技术国家重点实验室，武汉  430074
Published: December 2020

With the consideratioin of both defocused and abaxial cases,the analytical expressions for the 3D transfer function of optical low coherence tomography are derived in this paper.The theoretical stud-ies are concerned with the resolution-related factors,which furnish evidences for the designation and optimization of the systems.According to our study,the axis resolution would increase linearly with the spectral bandwidth,while the signal level would decrease linearly.In the case of defocused scan-ning,although longer focus length and narrower beam aperture could result in an absolute decrement of the resolution,they give an even better defocused imaging property in the whole scanning region.The detected waveform and the actual image of the optical coherence tomography are also given.
THE LINEAR RESPONSE OF BIEXCITON TO EXTERNAL ELECTRICAL FIELD IN POLYMER
Authors: ZHAO ER-HAI  , JIANG HAO  , WU CHANG-QIN  , XU XIAO-HUA  , SUN XIN  ,   复旦大学物理系，上海  200433；中国科学院红外物理国家重点实验室，上海  200083
Published: December 2020

In external electrical field,the self-trapping biexciton in non-degenerate ground state conjugated polymer has an abnormal characteristic-its static polarizability was found to be negative.We calculated the dynamic response function χ(ω) of biexciton.By putting ω to the zero limit,we got the static polarizability χ which proved to be negative.We compared it with that of self-trapping exciton and ground state and gave some analysis on the origin of negative polarizability.Finally,we investigated the behavior of χ(ω) when ω is small,and deduced that if more biexcitons are excited,the n(ω) of the material will decrease,whereas if more excitons are excited,the n(ω) will increase.
INTERFACE REFLECTION EFFECTS IN A MAGNETIC MULTILAYERED METALLIC SYSTEM
Authors: DONG ZHENG-CHAO  ,   淮阴师范学院物理系，淮阴  223001
Published: December 2020

Taking into account the scattering from bulk impurities and rough interfaces,we use the quantum-statistical Greens function approach and Kubo theory to calculate the one-particle Greens function and the conductivity in a magnetic multilayered metallic system.It is found that the conductivity depends on both the spatial size and the amplitudes for the reflected waves by the interfaces,and exbibits the main features of the giant magnetoresistance experiment.
CRITICAL BEHAVIOR AT THE SURFACE OF A SEMI-INFINITE MIXED-SPIN ISING SYSTEM WITH SURFACE RANDOM FIELD AND AMORPHISM
Authors: GAO ZHAN  , XU JIAN-HONG  , WANG ZHEN-LIN  ,   (1)江南学院数理部，无锡  214062; (2)南京大学物理系，南京  210093
Published: December 2020

In this paper,a renormalization group scheme within the framework of the mean field theory is used to investigate the critical behavior at the surface of a semi-infinite Ising system with mixed spins,i.e.,S=1 at the surface and σ=1/2 in the bulk.The effects of the random field and amorphism on the surface phase diagrams are obtained and discussed.The numerical results show that the surface tricritical points and reentrant phenomena exist due to the competition between the surface random field and certain magnitude of surface amorphization.
FORMALLY VARIABLE SEPARATION APPROACH AND NEW EXACT SOLUTIONS OF GENERALIZED HIROTA-SATSUMA EQUATIONS
Authors: CHEN LI-LI  ,   宁波大学物理系，宁波  315211
Published: December 2020

The usual formally variable separation approach is valid only for completely integrable models. In this paper, we extend the method to a nonintegrable generalized Hirota-Satsuma equations. Some new exact solitary wave solutions and periodic wave solutions of the equations are also obtained.
THE STATISTICAL NON-ERGODICITY OF THE EIGENSTATES OF THE QUANTUM CHAOTIC SYSTEMS AND ITS SEMI-CLASSICAL LIMIT
Authors: ZHANG FEI-ZHOU  , WANG JIAO  , GU YAN  ,   (1)中国科学技术大学非线性中心，合肥  230026; (2)中国科学技术大学天文与应用物理系，合肥  230026; (3)中国科学技术大学天文与应用物理系，合肥  230026；中国科学技术大学非线性中心，合肥  230026
Published: December 2020

In the semi-classical limit, the non-ergodicity of the eigenstates, θk(j), of circular unitary ensemble (CUE) are investigated. To study statistically the non-ergodicity of the eigenstates ofaquantumsystem, a pair of statistical functions,ΦN(j)=∑N-1k=0|θk(j)|4 and ΨN(j)=∑N-1k=0|θk(j)|2, are defined to show the scars and anti-scars respectively. In the frame of Random Matrix Theory,ΦN(j)s and ΨN(j)s for random orthohormal unit vectors are calculated. It is shown that their averages and fluctuations will tend to zero with the increase of N,while they follow the scaling laws. Compared with ΦN(j)s and ΨN(j)s obtained from the eigenstates of the quantum baker's transformation, it is found that, with the presence of scars (or antiscars), the fluctuations of the statistical functions of the eigenstates of the quantum baker's transformation will be greater than those of the random matrices, and tend to zero much slower in the semi-classical limit of N→∞.
ANALYTICAL POTENTIAL ENERGY FUNCTION FOR THE GROUND STATE (3Σ+u) OF UO2
Authors: WANG HONG-YAN  , GAO TAO  , YI YOU-GEN  , TAN MING-LIANG  , ZHU ZHENG-HE  , FU YI-BEI  , WANG XIAO-LIN  , SUN YING  ,   (1)四川大学原子分子物理研究所，成都  610065; (2)西南核物理和化学研究所，绵阳  621900
Published: December 2020

An analytical potential energy function for the ground state 3Σ+u of UO2 has been derived using many-body expansion method. The present paper correctly determines the dissociation limits, based on group theory and atomic and molecular reactive statics (AMRS). Using the MP2 (The HF calculation followed by a second-order Moller-Plesset correlation) of Gaussian94W and the RECP (the relativistic effective core potential) for U and basis 6-311G* for O,the present work has optimized the equilibrium geometry for the ground state 3Σ+u of UO2, which is linear O—U—O,whose equilibrium nuclear distance and dissociation energy are 0.17789nm and 14.1036eV.And the metastable structure U—O—O is discovered for the first time,to our knowledge,which is 5.7731eV higher than the stable structure.Then,the potential energy function is successfully used for describing the equilibrium geometry of UO2 and UOO,which is accurate enough in the whole region for dynamical research.
The Magnetic and Magneto-Optic Properties of the Amorphous TbCo/Si Multilayers
Authors: Chen Xi  , Wang Yin-Jun  , Liang Bing-Qing  , Wang Jing  , Li Jian  ,   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

The Tb0.17Co0.83/Si multilayers prepared by a rf magnetron sputtering system with different Si thickness have been investigated. X-ray diffraction, magnetic measurement and Kerr rotation have been performed. With increasing thickness of Si layer tSi, the perpendicular anisotropy constant Ku decreased rapidly. The saturation magnetization Ms and the Kerr rotation θK decreased linearly when tSi increased. It was assumed that Co2Si and Tb had been formed in the interfacial zone between TbCo and Si layers. The reduction of Ku, Ms and θK is attributed to the decrease of the effective thickness of magnetic layer, which is linear with tSi.
ATOMIC COHERENCE CREATED BY SPONTANEOUS EMISSION IN A Λ SYSTEM:LASING WITHOUT INVERSION
Authors: FAN YA-JING  , HU XIANG-MING  ,   华中师范大学物理系，武汉  430079
Published: December 2020

Atomic coherence in a Λ system may be created by spontaneous emission.In this paper it is shown that the coherence may lead to lasing without inversion and the features of the effect of the coherence on the laser gain is analyzed.
VARIOUS HYSTERESIS LOOPS AND MULTISTABILITY ON OUTPUT CURVES OF TUNABLE EXTERNAL CAVITY SEMICONDUCTOR LASERS
Authors: LI YAN  , CHEN JIAN-GUO  , LI DA-YI  , LU YANG  , ZHOU XIAO-HONG  ,   四川大学光电系，成都  610064
Published: December 2020

Optical bistabilities (multistabilities),which are due to the carrier-dependent refractive index of laser diodes (LD),observable on the output curves of tunable external cavity (EC) semiconductor lasers have been studied.As a result,various hysteresis loops with different shapes appearing on curves of N-ν (carrier density-oscillation frequency of external cavity semiconductor lasers) have been analyzed,and corresponding hysteresis loops on (power-frequency) curves have been also calculated.The expression relating reflectivities and spectral broadening factor,for observing the multistability on the N-ν(or P-ν) curves of ECLDs,has been established.
THE ALIGNMENT EFFECT OF NAPHTHALOCYANINE LB FILMS ON LIQUID CRYSTALS
Authors: LV RUI-BO  , XU KE-SHU  , ZHANG SHU-YAN  , GU JIAN-HUA  , LU ZU-HONG  ,   (1)东南大学分子与生物分子电子学开放实验室，南京  210096; (2)复旦大学物理系，三束材料改性国家重点实验室，上海  200433
Published: December 2020

Bis (trimethylsiloxy) silicon naphthalocyanine (SiNc) LB films were fabricated to align nematic liquid crystals. Films obtained under different surface pressures exhibit different alignment effects. Films obtained under surface pressure of 15mN/m will induce a planar alignment, while those obtained under 30mN/m will induce a homeotropic alignment. Atomic force microscopy reveals that on films prepared under high surface pressure the SiNc molecules stack into separate monomers or aggregates to form lines of nanometer size with molecular macrocycles perpendicular to the surface of the film and the dipping direction of its formation. In addition, there are grooves of molecular size between the stacked SiNc molecular lines. Similar formation occurs in films prepared under low surface pressures, only instead of molecules all lying perpendicular to the surface, many SiNc molecules are lying obliquely to the film surface or even lying on the surface. The mechanism of the liquid crystal alignment is also discussed.
Magnetostriction of (La1-yTby)0.67Sr0.33MnO3 Perovskite
Authors: Wu Jian  , Cao Qing-Qi  , Gu Kun-Ming  , Zhang Shi-Yuan  , Du You-Wei  ,   (1)河海大学数理系，南京 210098; (2)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 polycrystaline bulk samples of (La1-yTby)0.67Sr0.33MnO3(y=0,0.05,0.15,0.20,0.25,0.33,0.40,0.50,0.60,1.00) have been prepared by solid-phase reaction sintering. X-ray diffraction patterns show that the rhombohedral structure has been transfered into orthorhombic structure with increasing Tb content y. For the sample with y=0.40, a colossal magnetoresistance up to 900% has been observed at 180K. When μ0H=1.7T, the anisotropic magnetostriction (λt) of -50×10-6 and volume magnetostriction (ω) -130×10-6 have been observed for the samples of y=0.20 at room temperature, and y=0.33 at 210K respectively.
Colossal Magnetoresistance in Two-Element-Doped La-Ca-Ba-Mn-O
Authors: Zhu Xiang-Rong  , Shen Hong-Lie  , Shen Qin-Wo  , Li Tie  , Zou Shi-Chang  , Koichi Tsukamoto  , Mamoru Okutomi  , Takeshi Yanagisawa  , Noboru Higuchi  ,   (1)Electrotechnical Laboratory,1-1-4 Umezono,Tsukuba,Ibaraki 305-8568,Japan; (2)中国科学院上海冶金研究所信息功能材料国家重点实验室，上海 200050
Published: December 2020

Bullk materials of two-element-doped manganite La0.67(Ca0.6Ba0.4)0.33MnOz (LCBMO) which were prepared by solid state reaction method, where shown to have cubic polycrystalline structure. The magnetic and colossal magnetoresistive properties of LCBMO were investigated and were compared with those of one-element-doped La0.67Ca0.33MnOz (LCMO) and La0.67Ba0.33MnOz (LBMO)prepared by the similar technique. The results showed that the Curie temperature (TC) of LCBMO was 312K, which was between those of LCMO and LBMO, and that the metal-semiconductor transition temperature (Tp) and magnetoresistance (MR) peak temperature (Tm) of LCBMO under μ0H=0.6T field were 306 and 298K respectively, both of which were close to its TC and were also between the Tp and Tm of LCMO and LBMO. Under μ0H=0.6T applied field, the colossal magnetoresistance value at corresponding Tm was 41% for LCMO, 24.7% for LCBMO, 8% for LBMO, but at room temperature (300K) the MR value of LCBMO still reached 20%, which was greatly larger than those of LCMO and LBMO, i.e.2.0% and 2.4%, respectively. It was observed that at low temperatures far below Tm there still existed magnetoresistance effect in LCMO, and the MR value of LCBMO and LBMO increased with decreasing temperature. These magnetoresistance properties at low temperatures could be ascribed to the intrinsic structural characterstics such as grain boundaries and density.
Structures and Magnetic Properties of 3:29-Type Gd-Fe-Co-Cr Compounds
Authors: Yang Dong  , Wang Jian-Li  , Tang Ning  , Shen Yu-Ping  , Yang Fu-Ming  ,   中国科学院物理研究所磁学国家重点实验室，北京 100080
Published: December 2020

The structural and magnetic properties of synthetic Gd3(Fe1-xCox)25Cr4(0≤x≤0.6) and Gd3Fe29-yCry(3.5≤y≤5.0) compounds have been investigated. The structures of all the compounds are found to belong to the A2/m space group. Increase of Cr content leads to decreasing Curie temperature, decreasing saturation magnetization and decreasing anisotropy. Substitution of Co for Fe leads to a clear contraction of the unit-cell volume, but the increase of Curie temperature. Composition dependence of saturation magnetization at 5K reaches a maximum around x=0.3. It is noteworthy that substitution of Co for Fe results in a significant change of magnetocrystalline anisotropy of the Co sublattice, and changes of the easy magnetization direction of Gd3(Fe1-xCox)25Cr4 compounds from basal plane to easy axis.
SPIN-FORBIDDEN TRANSITIONS FOR BE-LIKE IONS (Z=10—103)
Authors: YI YOU-GEN  , WANG RONG  , LI XIANG-DONG  , WANG HONG-YAN  , ZHU ZHENG-HE  ,   (1)四川大学原子分子工程研究所，成都  610065; (2)湘潭师范学院物理系，湘潭  411201；四川大学原子分子工程研究所，成都  610065
Published: December 2020

A fully relativistic multiconfiguration Dirac-Fock method with Breit and QED cor rections is used to calculate the spin-forbidden 2s2 1S0—2s2p 3P1 (Z=10—103) transition energy level se parations and transition probabilities for the Be-like ions. The results are in good agreements with recent experimental data and other theoretical values. The results show that the spin-forbidden transition probabilities are in corresponde nce with these of E1 transitions and cannot be ignored in the laser plasma of hi gh temperature in ICF and MCF fusions.
APPLICATION OF DIRECT METHOD TO ELECTRON CRYSTALLOGRAPHIC IMAGE PROCESSING FOR T WO-DIMENSIONAL PROTEIN CRYSTALS
Authors: YANG SHI-XIN  , LI FANG-HUA  , LIU YU-DONG  , GU YUAN-XIN  , FAN HAI-FU  ,   中国科学院物理研究所和凝聚态物理中心，北京  100080
Published: December 2020

The direct method was applied to the image processing for [001] simulated high-r esolution electron microscope images of protein streptavidin.The image deconvolu tion was carried out for two images of different defocus values such that the st ructural information loss due to the zero crosses of contrast transfer function could be compensated.It is shown that the determined defocus values based on two images combined are closer to the true ones than those based on a single image. The phase extension was also carried out for this protein.The initial structure factors were calculated from the theoretical structure model,with the phases of 0.30nm resolution and amplitudes of 0.25nm resolution.Both the deconvoluted imag e of 0.30nm resolution and projected crystal structure of 0.25nm resolution obta ined are in agreement with the projected potential distribution maps of theoreti cal structure model.
EFFECTS OF DEPOSITION TEMPERATURE ON ELECTRICAL PROPERTIES OF HYDROGENATED AMORP HOUS CARBON FILMS
Authors: CHENG SHAN-HUA  , NING ZHAO-YUAN  , KAN JIAN  , MA CHUN-LAN  , YE CHAO  ,   苏州大学物理系，苏州  215006
Published: December 2020

Hydrogenated amorphous carbon films were deposited using ECR plasma with benzene as carbon source at varying substrate temperature. The effects of deposition te mperature on the resistivity and the intensity of electric break down have been investigated. The results show these properties depend on their growth condition s. The experiment results are further investigated using Raman spectra analysis.
XRD AND XPS STUDIES OF Bi2Sr2CaCu2-xSnxO8+δ SYSTEM
Authors: LI QI  , PAN HAI-BIN  , ZHU CHUAN-GANG  , XU PENG-SHOU  , ZHOU YANG-XUE  , ZHANG XIN-YI  ,   (1)南京大学物理系，固体微结构物理国家重点实验室，南京  210093；中国科学技术大学国家同步辐射实验室，合肥  230029; (2)中国科学技术大学国家同步辐射实验室，合肥  230029
Published: December 2020

X-ray diffraction and photoemission measurements have been carried out for Bi2Sr2CaCu2-xSnxO8+δ system. With Sn doping, lattice parameters a and c change somewhat, O1s and Cu2p core le vels shift differently in binding energy. From the experiment, we can deduce tha t the Sn ions are mostly in divalent state at small amount of doping, and in tet ravalent state at high doping level. Doping with Sn may have less influence on t he superconductivity than that with other elements. The results support the conc lusion that chemical environment plays a major role in the shifts of all core le vels in the high Tc superconducting samples.
ORDERED STRUCTURES OF BINARY ALLOY WITH HEXAGONAL CLOSE-PACKED LATTICE
Authors: SONG QING-GONG  , DAI ZHAN-HAI  , CONG XUAN-ZHONG  , WEI HUAN  , ZHANG QING-JUN  ,   (1)河北理工学院数理系，唐山  063009; (2)唐山师范学院物理系，唐山  063000
Published: December 2020

We have determined 10 ordered structure types and 14 perfect ordered structures of binary alloys with hexagonal close-packed lattice by using concentration-wave theory, and proposed an explanation for several typical experimental results.
THE MECHANISM OF MICROWAVE EXCITATION IN ArS2 SYSTEM
Authors: LIU XIAO-YA  , LI QUAN  , JIANG GANG  , ZHU ZHENG-HECHEN  , HAN-DE  , JIN XING-XING  , TANG YONG-JIAN  ,   (1)四川大学原子与分子物理研究所，成都  610065; (2)四川大学原子与分子物理研究所，成都  610065；西南核物理与化学研究所，绵阳  621900; (3)西南核物理与化学研究所，绵阳  621900
Published: December 2020

Based on ArS2 analysis potential function, which was calculated using ab initio MP2/6-31+G method and multi-body expansion theory, the dynamic proces s has been studied. The results indicated that the restraint of Ar and S2 due to physical adsorption, and the reaction of Ar and S2 is pri marily non-elasticity collision at a serial set of energies. Through analysis of inelastic collision products, it is shown that Ar atom can excite S2 (Ｘ3Σ－g) to S2(B3Σ－u) gradually.
THE PROBLEM OF INITIAL VALUE FOR THE PLANE TRANSVERSE ELECTROMAGNETIC MODE
Authors: CHEN RUI  ,   武汉市第二中学，武汉  430010
Published: December 2020

There actually does not exist the plane electromagnetic wave described by sutra theory that electric field and magnetic field are in phase everywhere. The solut ion of Maxwell equations depends on the original value of electromagnetic field or boundary conditions. According to different fixed-solution conditions, the p lane electromagnetic modes obtained are different. The results indicate that the plane electromagnetic wave is a transverse wave; at different positions, the a mplitudes of periodically changing magnetic field blazed by periodically changin g electric field are different, so are the amplitudes of periodically changing electric field blazed by periodically changing magnetic field. The phase differe nce between electric field and magnetic field is different too.
EXACT SOLUTIONS FOR THE INTERACTION BETWEEN NEUTRON SPIN AND GRAVITATION BY USING INVARIANT THEORY
Authors: SHEN JIAN-QI  , ZHU HONG-YI  , LI JUN  ,   (1)浙江大学现代光学仪器国家重点实验室,光及电磁波研究中心,杭州310027; (2)浙江近代物理中心及浙江大学物理学系,杭州310027; (3)浙江近代物理中心及浙江大学物理学系,杭州310027;浙江大学现代光学仪器国家重点实验室,光及电磁波研究中心,杭州310027
Published: December 2020

The existence of the interaction between the neutron spin and the gravitation in the experiment of neutron-gravitation interferometry,in addition to the Aharonov-Carmi effect (gravitational A-B effect),is proposed in the paper.The authors obtain the exact solutions to the time-dependent Schrdinger equation describing this interaction by making use of the invariant-related unitary transformation formulation.
CHEMICAL INSTABILITY AND MECHANICAL INSTABILITY IN ASYMMETRIC NUCLEAR MATTER
Authors: LI WEN-FEI  , ZHANG FENG-SHOU  ,   (1)兰州重离子加速器国家实验室原子核理论中心,兰州730000;中国科学院近代物理研究所,兰州730000; (2)兰州重离子加速器国家实验室原子核理论中心,兰州730000;中国科学院近代物理研究所,兰州730000;中国高等科学技术中心,北京100080
Published: December 2020

Using a temperature, density, isospin and momentum dependent equation of state of nuclear matter obtained within the framework of Extended Skryme Hartree Fock theory, we study the chemical and mechanical instabilities of nuclear matter at different temperatures, density and relative neutron excess,and compare them with the results of the simplified three-parameter potentials, namely soft and hard potentials in which the symmetry energy part is added by hand. It is found that the asymmetric nuclear matter has remarkable chemical instability in the mechanically stable region. The relationship between the mechanical and chemical instabilities is different from the result of soft and hard potentials, which is shown to result from the difference of the density dependence form of single particle potentials. We also provide the chemical and mechanical spinodal regions in pressure density plane, and their isospin dependence is discussed. In particular, the behaviours of chemical instability around the critical temperature and the possible consequences in heavy ion collisions at intermediate energy are investigated.
CONTRIBUTION OF THE BOUND STATES AND CONTINUUM STATES OF AN ATOM IN INTENSE LASER FIELDS TO HIGH HARMONIC GENERATION 
Authors: ZHOU XIAO-XIN  , LI BAI-WEN  ,   (1)西北师范大学物理系,兰州730070;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,武汉430071; (2)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,武汉430071
Published: December 2020

Solving the time-dependent Schrodinger equation for a one-dimensional atom in an intense laser field based on the basis function expansion and a linear-least-squares fitting method, we examine the influence of the bound states,-continuum states and the interference between them of the model atom on the high harmonic generation. It is found that the main contributions to the low-energy harmonic generations come from the bound-bound interaction, while the high-energy harmonic generations are from the bound-continuum interaction. Beyond the cut-off, the interference of the bound-bound and bound-continuum interactions leads to the disappearance of the harmonic generation.
GEOMETRICAL AND ELECTRONIC STRUCTURES OF VANADIUM CLUSTERS, AND THEIR EVOLUTION FROM MOLECULAR TO BULK PHASE 
Authors: DING CHANG-GENG  , YANG JIN-LONG  , LI QUN-XIANG  ,   中国科学技术大学选键化学开放实验室,合肥230026
Published: December 2020

We have optimized the geometrical structures of the vanadium clusters Vn and discussed their evolution with cluster sizes in the average nearest-neighbor distances, coordination numbers, binding energies, ionization potential, electron affinities, density of states, valence band width, and magnetic moments using the density functional theory.We found that the clusters from V2 to V9 have distinctly molecular behaviour with dramatic size variations; V13, V15, and V19 are the transition regions from the molecular features to the bulk structures, and V27 and V51 possess almost the bulk properties.
STUDY OF AUTO-CORRELATION PROPERTIES OF DIFFUSING LIGHT IN ULTRASOUND-MODULATED MEDIA
Authors: ZHANG XI-QIN  , XING DA  ,   华南师范大学激光生命科学研究所,广州510631
Published: December 2020

In this paper,the temporal auto-correlation properties of diffusing light in ultrasound-modulated random media were studied.The mathematical expression of auto-correlation function of diffusion light in an infinite medium modulated by ultrasound was obtained.The influences of ultrasound and scattering parameters on modulation parameter,modulation amplitude and its decaying were discussed.The feasibility of imaging an object hidden in random media with an auto-correlation function was also studied by use of Monte Carlo simulations.The ultrasound-modulated auto-correlation functions of normal and diseased tissues are different,which can be used to diagnosis diseased tissue hidden in normal tissue.
EXPANSION METHOD ABOUT THE JACOBI ELLIPTIC FUNCTION ANDITS APPLICATIONS TO NONLINEAR WAVE EQUATIONS
Authors: LIU SHI-KUO  , FU ZUN-TAO  , LIU SHI-DA  , ZHAO QIANG  ,   (1)北京大学地球物理系,北京100871; (2)北京大学地球物理系,北京100871,北京大学湍流研究国家重点实验室,北京100871
Published: December 2020

A Jacobi elliptic function expansion method is proposed to construct the exact periodic solutions of nonlinear wave equations. This new method contains the hyperbolic tangent expansion method, and the periodic solutions obtained by this method, include the shock wave solutions and the solitary wave solutions.
DISENTANGLEMENT OF 3-PAETICLE SYSTEMS
Authors: FENG JIAN  , WANG JI-SUO  , GAO YUN-FENG  , ZHAN MING-SHENG  ,   (1)聊城师范学院光通信研究所,聊城252059; (2)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,武汉430071; (3)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,武汉430071;中国科学院安徽光学精密机械研究所激光光谱学开放研究实验室,合肥230031;聊城师范学院光通信研究所,聊城252059
Published: December 2020

Three kinds of definitions of disentanglement of 3-particle systems are given. Three basic regulations of a 3-particle system pure-state disentanglement are completely analyzed. It is shown that there are some sets of 3-particle entangled states that can be disentangled into product states or 1-particle product and 2-particle separable states or fully separable states, but a universal disentangling machine into product states or 1-particle product and 2-particle separable states or fully separable states cannot exist.
NONLINEAR ADAPTIVE PREDICTIVE TARGETING CONTROL OF THE CONTINUOUS CHAOTIC SYSTEMS
Authors: ZHANG JIA-SHU  , XIAO XIAN-CI  ,   (1)电子科技大学电子工程系,成都610054; (2)电子科技大学电子工程系,成都610054;西南交通大学计算机与通信工程学院,成都610031
Published: December 2020

The sigmoid-Volterra adaptive predictors are used to perform nonlinear adaptive predictive targeting control of chaos in continuous chaotic systems based on the nonlinear adaptive predictive principle of chaotic time series, where the nonlinear adaptive controller acts on only one-dimensional time series coming from the chaotic state of the controlled system. This adaptive predictive targeting controller can control the system to any desired state by means of adaptive cancellation. Computer simulation results on the Lorenz and Rǒssler systems are shown to demonstrate the effectiveness of this nonlinear adaptive predictive targeting control method. The advantages of this new method are that it does not need to know the accurate equations or to identify the system′s model of the controlled chaotic systems.
A THEORETICAL STUDY ON ELECTRON ANGULAR DISTRIBUTIONS FOR (e,2e) PROCESSES ON HYDROGEN
Authors: ZHANG SUI-MENG  , WU XING-JU  ,   安徽皖西学院物理系,六安237012
Published: December 2020

In this work the triple differential cross sections for electron impact ionization of atomic hydrogen at different energies are calculated by use of 3C and DS3C models. The structure of the cross sections is analysed. It is seen that the angular distribution basically consists of two peaks which can be assigned to the binary and recoil peaks. The shape and position of the two peaks depend sensitively on the detection geometry and the energy shared between the two electrons. Furthermore, the final-state electron-electron repulsion contributes significantly to the form of the observed angular distributions. For different collision geometry, the three-body interactions will control the interference pattern of various scattering amplitudes by different weighting between these amplitudes. In addition, the direct and exchange amplitudes are also considered.
ONE-DIMENSIONAL DARK SOLITONS IN PHOTOVOLTAIC MEDIA WITH A POSITIVE PERTURBATION REFRACTIVE INDEX
Authors: SHE WEI-LONG  , WANG XIAO-SHENG  , HE GUO-GANG  , TAO MENG-XIAN  , LIN LI-PING  , LEE WING-KEE  ,   (1)香港中文大学物理系和材料科学技术研究中心,香港; (2)中山大学超快速激光光谱学国家重点实验室,广州510275
Published: December 2020

We present a theory of photovoltaic(PV) spatial solitons(SS's), that includes the PV contribution of a background beam(BB). The theory predicts that a dark or a bright SS can be formed in the same crystal with positive refractive index perturbation (Δn). If the ratio (R) of the effective Glass constants(EGC) of the BB to that of the signal beam(SB) is1. We have formed a one-dimensional dark PV SS in a crystal, as predicted.
STUDY ON DYNAMICS OF RELATIVISTIC BIRKHOFF SYSTEMS
Authors: FU JING-LI  , CHEN LI-QUN  , LUO SHAO-KAI  , CHEN XIANG-WEI  , WANG XIN-MIN  ,   (1)商丘师范学院数学力学与数学物理研究所,商丘476000; (2)上海大学上海市应用数学与力学研究所,上海200072
Published: December 2020

The Birkhoffian, the Birkhoff's functions, the Pfaff action, the Pfaff-Birkhoff principle and the Birkhoff equations of relativistic Birkhoff systems are given. The Birkhoff representation of relativistic dynamical systems is studied. Then the theory of Noether symmetries and Lie symmetries of the relativistic Birkhoff systems is obtained by the invariance of relativistic Pfaff action and relativistic Birkhoff equations under infinitesimal transformations. Finally the algebraic structure and Poisson integrals for the relativistic Birkhoff systems are studied.
FABRICATION OF LARGE CONE ANGLE OPTICAL FIBER PROBE BY DYNAMIC CHEMICAL ETCHING METHOD
Authors: SUN JIA-LIN  , TIAN GUANG-YAN  , LI QIN  , ZHAO JUN  , GUO JI-HUA  , XIE AI-FANG  , ZHANG ZE-BO  ,   (1)清华大学物理系单原子分子测控教育部重点实验室,北京100084; (2)中国科学院物理研究所光物理实验室,北京100080
Published: December 2020

According to the hydraulic transmission principle, a device for fabricating large cone angle near-field optical fiber probe by means of dynamic chemical etching is developed. The results indicated that in the course of traditional fabrication of optical fiber probes by chemical etching, the configuration and the cone angle of the taper can be controlled efficiently through controlling the velocity of the lifting of etching fluid. Furthermore, The advantage of controlling the displacement between optical fiber probe and etching fluid step by step in the fabrication of large cone angle optical fiber probe is also described in this paper. A large cone angle near-field optical fiber probe in scanning near-field optical microscopy is applied to measuring the sphere with a diameter 200nm. Its force images show that this probe has high topography resolution (～50nm).
ATOMIC STRUCTURE OF THE Ge(112)-(4×1)-In RECONSTRUCTION
Authors: TU XIU-WEN  , GAI ZHENG  ,   北京大学物理系人工微结构和介观物理国家重点实验室,北京100871
Published: December 2020

We have studied the Ge(112)-(4×1)-In reconstruction with scanning tunneling microscopy (STM). Based on our bias dependent STM images and the characteristic electronic structure of stable submonolayer group Ⅲ-metal/group-Ⅳ-semiconductor interfaces, we propose an atomic model of this reconstruction for further investigation. The adsorption sites of In atoms are the same as In atoms' adsorption sites in the Si(112)-(7×1)-In reconstruction, but are different from the adsorption sites of Al and Ga atoms on the Si(112) surface. We suggest that this difference in adsorption sites is mainly due to the longer covalent bond length of In atoms. We further propose that, due to the smaller misfit, Al and Ga atoms may form longer nano wires along the step edges on the Ge(112) surface.
SiC NANOWIRES GROWN ON SILICON(100) WAFER BY MPCVD METHOD
Authors: HU YING  ,   首都师范大学物理系,北京100037
Published: December 2020

Silicon carbide nanowires have been grown on single crystal silicon wafers by using microwave plasma chemical vapor deposition method. The nanowires are analyzed by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy and low-energy electron diffraction methods. The growth mechanism of nanowires is proposed.
ROOM-TEMPERATURE 1.54μm Er3+ PHOTOLUMINESCENCE FROM Er-DOPED SILICON-RICH SILICON OXIDE FILM GROWN BY MAGNETRON SPUTTERING
Authors: YUAN FANG-CHENG  , RAN GUANG-ZHAO  , CHAN YUAN  , ZHANG BO-RUI  , QIAO YONG-PING  , FU JI-SHI  , QIN GUO-GANG  , MA ZHEN-CHANG  , ZONG WAN-HUA  ,   (1)北京大学物理系,北京100871; (2)北京大学物理系,北京100871,泉州师院物理系,泉州362000; (3)信息产业部电子第十三研究所,石家庄050051
Published: December 2020

Room temperature photoluminescence (PL) has been observed from Er doped silicon rich silicon oxide films grown by magnetron sputtering. For all kinds of silicon rich silicon oxide films grown with different excess Si contents, each PL spectrum has two peaks at 1.54 and 1.38μm, which originate from Er3+ and a certain kind of defects, respectively, in the silicon rich silicon oxide. It was found that 1.54 and 1.38μm PL peak intensities are correlated with each other. The PL intensity-dependence on the excess-Si content and annealing temperature was studied in detail.
INFRARED ANALYSIS OF BOND CONFIGURATION FOR THE a-C∶F∶H FILMS DEPOSITED AT VARIABLE CHF3/CH4 FLOW RATIOS
Authors: XIN YU  , NING ZHAO-YUAN  , GAN ZHAO-QIANG  , LU XIN-HUA  , FANG LIANG  , CHENG SHAN-HUA  ,   (1)苏州大学化学系,苏州215006; (2)苏州大学物理系,苏州215006
Published: December 2020

a-C∶F∶H films are prepared by microwave ECR plasma-enhanced chemical vapor deposition method at variable CHF3/CH4 gas flow raitos. The results from the Fourier transform-infra-red abserption for these films have shown that a structural evolution of the a-C∶F∶H film occurs at variable flow ratios R =[CHF3]/([CHF3]+[CH4]). The main structure of the films is diamond-like carbon (DLC) characteristics for R less than 64%. The film presents a structure of PTFE-like as R is larger than 64%, where the dominant structural monomer is —CF2. Meanwhile, this structural evolution has also an influence on optical gap of the films. Optical gap decreases with the increase of flow ratios in the region of DLC-like characteristics, while increasing in the PTFE-like region. The transmittance of the a-C∶F∶H film is close to 100% for R larger than 92%.
Application of fuzzy set theory to color image retrieval*
Authors: Liang Yan-Mei  , Zhai Hong-Chen  , Mu Guo-Guang  ,   (1)光电子信息技术科学教育部重点实验室,天津300071; (2)南开大学现代光学研究所,天津300071
Published: December 2020

We report an application of fuzzy relations in fuzzy set theory to the calculation of the similarity between colors, and apply it to the color image retrieval, where only a membership function is used as a measure of the similarity between the characteristic color vectors of a query image and of the images in the database. A match between two colors is defined as the α-cut fuzzy relation.In the comparison process, screening with decreasing by orders for comparisons and a method of regional color vector comparison are developed, which effectively reduce the color correlation in the red-green-blue (RGB) space and save from massive unnecessary calculations. Our theoretical and experimental results show clearly the advantages of our approach in both accuracy and speed of the color image retrieval.