bluuebunny/crossref_metadata_2025 huggingface dataset:
PHOTOLUMINESCENCE STUDY FOR NANOMETER Ge PARTICLES EMBEDDED Si OXIDE FILMS
Authors: MA SHU-YI  , ZHANG BUO-RUI  , QIN GUO-GANG  , HAN HE-XIANG  , WANG ZHAO-PING  , LI GUO-HUA  , MA ZHEN-CHANG  , ZONG WAN-HUA  ,   (1)北京大学物理系，北京  100871; (2)电子工业部第十三研究所，石家庄  050051; (3)中国科学院半导体研究所，半导体超晶格国家重点实验室，北京  100083
Published: November 2020

Using a Ge-SiO2 (GSO) composite target with the Ge wafer in the target having percentage areas of 0%,5% and 10%,three types of nanometer Ge particles embedded Si oxide films were deposited on p-type Si substrates by the rf magnetron sputtering technique. These samples were annealed in a N2 atmosphere at 300,600,800 or 900℃ for 30min.From Raman scattering spectra,we obtained the sizes of nanometer Ge particles which increase with increasing percentage area of the Ge wafer in the sputtering target.From the fitting of Raman scattering spectra,average diameters of nanometer Ge particles in the GSO(5%) sample increase from 5.4 to 9.5nm with annealing temperature increasing from 600 to 900℃. The peak with energy around 2.1eV exists in the photoluminescence spectra of all the different sizes of nanometer Ge particles embedded silicon oxide samples.The photoluminescence spectrum of the silicon oxide film prepared using a pure SiO2 target has other two peaks with light emission energies around 1.9 and 2.3eV respectively. The experimental facts are inconsistent with the predication of the quantum confinement model,but can be explained by the quantum confinement/luminescence center model.
MAGNETIC PROPERTIES OF Fe/SnO2 AMORPHOUS MULTILAYERS
Authors: LOU JIAN-XIN  , LIU YI-HUA  , HUANG BAO-XIN  , ZHANG LIN  , ZHANG RU-ZHEN  , ZHANG WEI-JIAN  , ZHANG LIAN-SHEN  ,   山东大学物理系，济南  250100
Published: November 2020

Magnetic properties of Fe/SnO2 amorphous multilayers prepared by rf sputtering are investigated. With the thickness ds of SnO2 layers fixed (5.0nm),the saturation magnetization Ms　of the samples decreases with decreasing dm. This is due to the contributions from the dead-layer effect and the dimensional effect. On the other hand, when the dm of the samples is very thin, quasi-two-dimensional magnetic behavior is found. The Curie temperature TC decreases with decreasing dm, and coercivity Hc has a peak as dm varies. With the thickness of Fe fixed at 2nm, Ms increases with decreasing ds.
NUCLEATION AND INITIAL GROWTH OF DIAMOND BY BIASED HOT FILAMENT CHEMICAL VAPOR DEPOSITION
Authors: LIAO KE-JUN  , WANG WAN-LU  , FENG BIN  ,   重庆大学应用物理系，重庆  400044
Published: November 2020

The nucleation and initial growth of diamond on Si(100) by biased hot filament chemical vapor deposition have been studied by scanning electron microscopy,Raman spectra,infrared absorption spectra and X-ray photoelectron spectra.After bias pretreated for 15min at -300V and 100mA,the nucleation density was found to be over 1010cm-2 on mirror-polished Si and was inhomogeneous,which can be divided into three regions on Si surface:A,cones at the edges;B,nanocrystalline diamond at the transition region between the edge and the centre;and C,SiC layers at the centre.The films with defects,textured films,and big discrete grains of diamond were formed at A,B,C regions respectively after 4h growth without bias.The nucleation enhancement by substrate negative bias is believed to be a combination effect of the ion bombardment and emission electron.The non-uniformity of ion distribution led to an uneven nucleation on the Si substrate surface.
TRANSMISSION AND REFLECTION OF SOLITON IN AN INHOMOGENEOUS PLASMA
Authors: DUAN WEN-SHAN  , Lv KE-PU  , WANG BEN-REN  , WEI RONG-JUE  ,   (1)南京大学声学研究所，南京  210093; (2)西北师范大学物理系，兰州  730070
Published: November 2020

Transmission and reflection of soliton in an inhomogeneous plasma are investigated, the transmission and reflection waves both can be described by the KdV equation in the lowest order. The numbers and magnitude of both transmitted and reflected solitons from an incident soliton are given analytically.
DECISIVE INFLUENCE OF THE DYNAMIC BEHAVIOR OF THE ATOMIC DIPOLE MOMENT ON THE QUANTUM STATISTICAL PROPERTIES OF LASER FIELD
Authors: HUANG WEN-JIN  , HUANG HU  , LI SHI-QUN  ,   清华大学现代应用物理系，北京  100084
Published: November 2020

In this paper we derive the Fokker-Planck equation of a closed lasing system by using ordering techniques of operators, reduce it to an equation including merely field variables, and then obtain the Q function of the laser field. Through analyzing the Q function, we discover that,at the operating point, the dynamic behavior of the dipole moment between the lasing levels decisively influences the quantum statistical properties of the laser field. Under certain conditions we obtain a clear picture about the influence. The conclusion can be applied to a variety of laser systems, including those without inversion.
FREQUENCY DEPENDENCE ON INTERNAL FRICTION PEAK ASSOCIATED WITH PHASE TRANSITION OF LIQUID CRYSTAL CARBOXYLATE
Authors: LIU YONG-SONG  , SHUI JIA-PENG  ,   中国科学院固体物理研究所内耗与固体缺陷开放研究实验室，合肥  230031
Published: November 2020

The phase transition of liquid crystal carboxylate is studied by using low-frequency internal friction method, under forced-vibration mode. A relationship between the height of the peak of internal friction and the vibration frequency is derived with a simple viscoelastical Maxwell model; it shows a nonlinear feature. The experimental result agrees with this relationship.
THEORETICAL ANALYSIS OF FAST AND SLOW SATURABLE ABSORBER MODE LOCKING ERBIUM DOPED FIBER LASERS
Authors: HUANG ZHI-JIAN  , SUN JUN-QIANG  , HUANG DE-XIU  ,   华中理工大学光电子工程系，武汉  430074
Published: November 2020

This paper presents a theoretical model for erbium-doped fiber lasers, which are passively mode-locked by a semiconductor saturable waveguide acting as a slow saturable absorber and a nonlinear fast saturable absorber- The influences of semiconductor saturable waveguide, fiber self-phase modulation and self-amplitude modulation on mode-locking pulse width and chirp have been analyzed-
DIFFUSION OF ALUMINUM IN DOUBLE QUANTUM WELL STRUCTURE UPON RAPID THERMAL ANNEALING
Authors: XU ZUN-TU  , XU JUN-YING  , YANG GUO-WEN  , ZHANG JING-MING  , YIN TAO  , ZHAO HONG-DONG  , LIAN PENG  , SHEN GUANG-DI
Published: November 2020

We have investigated theoretically and experimentally the impurity-free vacancy induced disordering for GaAs/AlGaAs double quantum well laser structure grown by MBE with capped SiO2 by repid thermal annealing. The position of the photoluminescence peaks, due to the n=1 electron to heavy-hole transition, was measured before and after annealing the samples. As a result, the samples annealed rapidly show blue shift in the position of photoluminescence peaks and the magnitude of shift increases with increasing temperature. We analyzed theoretically the Al-Ga interdiffusion process in GaAs/AlGaAs quantum well structure and the experimental energy shifts were compared with a theoretical model to obtain the diffusion coefficient of aluminum into the quantum well at different temperatures and the activation energy of aluminum diffusion process. The aluminum diffusion coefficient in the sample annealed at 950 ℃ for 30 s is 6.6×10-16 cm2/s. The activation energy found is 5.0 eV.
STRUCTURAL AND MAGNETIC PROPERTIES OF ErFe11-xCoxTi COMPOUNDS
Authors: WANG JIAN-LI  , YANG FU-MING  , TANG NING  , HAN XIU-FENG  , YANG DONG  ,   中国科学院物理研究所磁学国家重点实验室，北京  100080
Published: November 2020

X-ray diffraction patterns and thermomagnetic curves show that all compounds are almost of single phase.All ErFe11-xCoxTi compounds (x=0—11) crystallize in the ThMn12-type structure.Substitution of Co for Fe leads to an increase of Curie temperature and a monotonic decrease of lattice constants.The composition dependence of saturation moments exhibits a maximum at about x=3. The easy magnetization direction (EMD) at room temperature,for x≤4, is along the c-axis, for 6≤x≤9,is perpedicular to the c-axis, while for further increasing x, it goes back to the c-axis. The interesting change of EMD of ErFe11-xCoxTi compounds may result from the preferential occupation of Co and the different contribution to the magnetocrystalline anisotropy from different transition-metal sites.For all ErFe11-xCoxTi compounds, a spin reorientation occurs below the Curie temperature.A tentative phase diagram for ErFe11-xCoxTi compounds has been given.
n-POLYMER IREEVERSIBLE KINETIC AGGREGATION WITH SOURCE-REINFORCED
Authors: XUE YU  , CHEN GUANG-ZHI  ,   广西大学物理系，南宁 530004
Published: November 2020

We discussed the kinetics of n-polymer aggregation processes with source-reinforced, The asymptotic expression of Cm(t) is obtained by the steady-state solution of generalized Smolu-chovski's equation with source. Universal power law distributions of cluster size are obtained in gelling systems.
THERMAL CONDUCTIVITY OF Cr75FexMn25-x(x=16,18) ALLOYS
Authors: WU BAI-MEI  , YANG DONG-SHENG  , SHENG SONG  , XU WEI-MING  , CHEN ZHAO-JIA  ,   (1)中国科学技术大学物理系，合肥 230026; (2)中国科学院低温技术实验中心,北京 100080
Published: November 2020

The thermal conductivity and the electrical conductivity of Cr75FexMn25-x(x=16,18) alloys have been measured over the temperatures range from 77K to 300K. The change of slope on thermal conductivity-temperature curve and the maximum on electrical conductivity-temperature curve have been found near the transition temperature of spin density wave type antiferromagnetism, which is related to the opening of the energy gap. Both alloys exhibit a rise in the phonon thermal eonductivity with decreasing temperature as being characteristic of umklapp processes.
(2+1) REMPI SPECTRUM OF RYDBERG STATES OF S ATOMS IN THE 243—263 nm REGION
Authors: ZHANG LI-MIN  , CHEN JUN  , XU HAI-FENG  , DAI JING-HUA  , LIU SHI-LIN  , CHEN CONG-XIANG  , MA XING-XIAO  ,   中国科学技术大学化学物理系,合肥 230026
Published: November 2020

About 50 spectral lines due to the (2+1) resonance-enhanced multiphoton ionization (REMPI) of atomic sulfur, generated in the sequential multiphoton dissociation of SO2 at probing wavelengths, in the 243—263 nm region has been observed. Besides most of the lines which are due to the two-photon transition from the ground states 3P2,1,0 to the Rydberg states 3P, 3D, 3F until n=10 of S atom, several new lines including the spin forbbiden transition 1P0, 5S0←3P and the two-photon transitions from the excited state 1D2 to the Rydberg states np1,3D, 1,3F are observed. Intensities of some lines have been calculated and compared with the experimental results.
SIMULATION AND DISCUSSION OF THE LATTICE DISTORTION AND ELASTIC MODULUS OF NANOCRYSTALS
Authors: CHANG MING  , YANG BAO-HE  , CHANG HAO  ,   (1)合肥工业大学应用物理系,合肥 230009; (2)天津理工学院光电信息科学系，天津 300191
Published: November 2020

This paper reports a molecular dynamics simulation for atomic structure of copper nanocrystals, in which the grain size and lattice distortion were computed by X-ray differaction simulation, and the distribution of energy and elastic modulus was calculated. The results show that the lattice distortion was stored not only at grain boundaries but also in the grain. The increase of atomic radius leads to the reduction of the elastic modulus of the nanocrystals.
A STUDY ON RADIATION DAMAGE MECHANISM IN PbWO4 SCITILLATING CRYSTALS
Authors: FENG XI-QI  , HAN BAO-GUO  , HU GUAN-QIN  , ZHANG YAN-XING  ,   中国科学院上海硅酸盐研究所无机功能材料开放研究实验室，上海　200050
Published: November 2020

A representative PbWo4 sample was annealed subsequently from 640 to 1040℃ in air and the optical absorption spectra were measured after each annealing step. It was found that the intrinsic color center absortion band peaking at 350 nm increased after annealing at lower temperature, then with increasing annealing temperature it decreased continuously until it was removed finally. Based on the analysis of intrinsic defects and corresponding charge compensation of PbWO4 crystals, the creation and transformation of the color center were discussed. This was caused by the diffusion of oxygen, entering into PWO crystals during the annealing process. It was supposed that a Pb3+→Pb4+ transformation probably occurred in the annealing process, it would lead to annihilation of Pb3+ centers. The UV radiation induced color center absorptions of PWO crystals annealed at different temperatures were measured and compared. It has been observed that the O- hole centers as the main product of the radiation damage of PWO crystals were produced predominantly from the transformation of the intrinsic Pb3+ hole centers. On the other hand, oxygen vacancies VO as electron trap centers trapped the electrons during irradiatiion, thus stabilizing O- hole centers. When those two factors have been removed by means of annealing at high temperature in air(oxygen abundant atmosphere), the radiation hardness of PWO crystals can be effectively improved. While, the iron impurity in crystals is very harmful for the radiation hardness of PWO crystals.
TRANSIENT HEATING BEHAVIOR IN PLANAR NEMATIC LIQUID CRYSTAL USING PHASE RETARDATION METHOD
Authors: LIN ZI-YANG  , XIANG YING  , WU ZE-DA  , LI YU-XIN  ,   (1)暨南大学物理系，广州 510632;中山大学物理系，广州　510276; (2)中山大学物理系,广州　510276
Published: November 2020

By means of the optical phase retardation method the YAG laser was used to observe the transient heating behavior in planar nematic liquid crystals. According to the experimental results, heating effect may induce molecular reorientation in liquid crystals. Azo-dye and photoisomerized-dye in planar nematic liquid crystals have little effect on heating behavior, but the liquid crystal doped with chiral molecules shows temporary memory effect.
ANALYSIS ON ENERGY ABSORPTION EDGE AND ELECTRON POPULATIONS OF Al
Authors: TIAN SHU-FEN  , FAN XI-JUN  , YU LUO-PING  , J.S.BOW  , R.W.CARPENTER  , S.H.LIN  ,   (1)Center for Solid State Science,Arizona State University,Tempe,AZ85287,USA; (2)山东师范大学物理系，济南  250014; (3)山东师范大学现代教育技术研究所，济南  250014
Published: November 2020

A theoretical explanation for L core-shell absorption edge of electron energy loss spectrum of Al, an analysis of the electronic populations and a comparison between different partial cross sections are given. The edge was first normalized to the same atomic ionization cross section (per atom per electronvolt). The contributions for the cross section come from three respects:the first one is the electronic transitions from the core-shell to valence-shell calculated by extended Hückel band model, the second one is the final ionization state obtained by electron gas model, the third comes from the elastic backscatting of outgoing waves by the atoms that neighbor the excited atom. The agreement between the calculation result and the experimental result is good.
SIMULATION ON MULTIPLE CLUSTER GROWTH IN ULTRA-THIN FILMS
Authors: WANG XIAO-PING  , ZHAO TE-XIU  , WU FENG-MIN  , LIN GANG  , WU ZI-QIN  ,   (1)浙江工业大学技术物理研究所,杭州 310014; (2)中国科学技术大学天文与应用物理系,合肥 230026; (3)中国科学技术大学物理系,合肥 230026; (4)中国科学技术大学物理系,合肥 230026；中国科学技术大学天文与应用物理系，合肥 230026
Published: November 2020

The multiple cluster growth with fractal or compact morphology in ultra-thin films has been simulated with various permitted diffustion steps. It is shown that the fractal dimension increases with increasing cluster size in the fractal growth. The nucleation rate decreases with increasing diffusion steps and drops rapidly with increasing deposition time. The cluster size S can be described by a power law as S-(t-t0)κ, where (t-t0) is the growth time. The growth index κ is slightly smaller than 1 given by the classical nucleation and growth theory, due to the branching effect between clusters. A nonlinear phenomenon (i.e., the larger the cluster size, the larger the growth index κ) has been obtained.
RADIATION-INDUCED SEGREGATION IN HYDROGEN-IMPLANTED Fe-1wt%Ni ALLOY
Authors: WAN FA-RONG  , CHU WU-YANG  , SIAO JI-MEI  , TAKAHASHI HEISHICHIRO  ,   (1)北京科技大学材料物理系,北京 100083; (2)日本北海道大学,日本 060
Published: November 2020

Radiation-induced segregation of Ni element in Fe-1 wt%Ni alloy was investigated by ion accelerator and high voltage electron microscope. The results show that the complexes of Ni, vacancy and hydrogen diffuse towards voids due to the inverse Kirkendall effect. Ni atoms would precipitate along {110} planes near voids. Streak diffraction pattern from the coherent precipitates of Ni can be observed.
SIMULATION OF DIELECTRIC LOSS RELATED WITH THE MOTION OF DOMAIN WALLS
Authors: CHEN XIAO-BING  , YAN FENG  , LI CHUN-HUA  , ZHU JIN-SONG  , SHEN HUI-MIN  , WANG YE-NING  ,   南京大学固体微结构物理国家重点实验室,南京 210093
Published: November 2020

The measurement of dielectric susceptibility under various frequencies for Pb(Zr0.52Ti0.48)O3 (PZT) ceramics shows that there exists a dielectric loss peak below and close to phase transition temperature, which is relaxational characteristic but disagrees with Arrhenius relation. The peak arise from the interaction between domain walls, lattice and pinning defects. In this paper the behavior of the dielectric loss peak of PZT under various frequencies is simulated by using the dynamic equation of viscous motion of domain walls and by considering the Curie temperature dispersion in ceramics as well. The agreement between the simulatied result and experimental data is quite satisfactory. And from the parameters of simulation the viscous coefficient of the motion of domain walls and the recovering force constant of pinning defects are calculated.
INTEGRAL TRANSFORMATION WITH CHANGEABLE COEFFICIENT AND LANDAU SYSTEMS IN THE FRAMEWORK OF NONLINEAR-SUPERSYMMETRY METHOD
Authors: JING HUI  , SHI  QING-YUN  ,   郑州大学物理系，郑州  450052
Published: November 2020

We present a generalized integral transformation with changeable coefficient,and show that the case of electromagnetic field interaction could be settled by nonlinear-suppersymmetry method.As an example,Landau systems are analyzed.
EVOLUTION OPERATOR AND WAVE FUNCTION OF A TIME-DEPENDENT OSCILLATOR
Authors: XU XIU-WEI  , LIU SHENG-DIAN  , REN TING-QI  , ZHANG YONG-DE  ,   (1)烟台师范学院物理系，烟台  264025; (2)中国科学技术大学近代物理系，合肥  230027
Published: November 2020

From the generalized linear quantum transformation theory,we obtain the normal product form of evolution operator and the wave function for a time-dependent oscillator.
A STUDY ON STRANGE DYNAMICS OF A TWO-DIMENSIONAL MAP
Authors: HE DAI-HAI  , XU JIAN-XUE  , CHEN YONG-HONG  ,   西安交通大学非线性动力学研究所，西安  710049
Published: November 2020

The nonlinear dynamics of a two-dimensional map system on a plane is studied.We found that the attractor of the system changed from stable focus，stable invariant circle(limit circle) to the chaotic attractor contracted into low-dimensional manifold with o
STATIC AND DYNAMIC ANALYSIS OF PHASE SHIFT DISTRIBUTED FEEDBACK LASER DIODES
Authors: SHEN DAN-XUN  , GU WAN-YI  , XU DA-XIONG  ,   北京邮电大学电信工程学院，北京  100876
Published: November 2020

Using transfer matrix method with rate equations and couple wave theory,the static and dynamic analysis of 3PS-DFB and QPS-DFB diodes are presented.With vector processing rather than NR algorithm,carrier density and photon density distribution of the two
COMPARISON OF RESULTS OBTAINED FROM TEMPERATURE MEASUREMENT AND NUMERICAL SIMULATION OF DC PLASMA ARC
Authors: SHAO QI-YUN  , HE YU  , GUO WEN-KANG  , XU PING  , ZANG DE-HONG  ,   复旦大学现代物理研究所，上海  200433
Published: November 2020

The computational method of temperature distribution of free-burning arc is investigated by using a numerical simulation model, which is based on the local thermodynamic equilibrium. A spectrum temperature diagnostic system of plasma torch based on charge
FAST WAVE MINORITY ION HEATING
Authors: ZHU XUE-GUANG  , KUANG GUANG-LI  , ZHAO YAN-PING  , LI YOU-YI  , XIE JI-KANG  ,   中国科学院等离子体物理研究所，合肥  230031
Published: November 2020

The mechanism of fast wave minority ion heating is discussed in some detail. The ray tracing algorithm is used to simulate fast wave heating for the plasma of two kinds of ions, and the calculation results of different ratios of two ions' density is obtai
TRANSPORT OF ELECTRONS IN DOUBLE-BARRIER MAGNETIC STRUCTURES UNDER A CONSTANT ELECTRIC FIELD
Authors: WANG HAO  , GUO YONG  , GU BING-LIN  ,   清华大学现代应用物理系，北京  100084
Published: November 2020

We have investigated transport properties of electrons in magnetic quantum structures under an applied constant electric field.The transmission coefficient and current density have been calculated for electron tunneling through structures consisting of id
MORPHOLOGY AND PHOTOLUMINESCENCE OF GeSi SELF-ASSEMBLED QUANTUM DOT ON Si(113)
Authors: SI JUN-JIE  , YANG QIN-QING  , TENG DA  , WANG HONG-JIE  , YU JIN-ZHONG  , WANG QI-MING  , GUO LI-WEI  , ZHOU JUN-MING  ,   (1)中国科学院半导体研究所，集成光电子学国家重点实验室，北京  100083; (2)中国科学院物理研究所，北京  100080
Published: November 2020

Morphology of self-assembled GeSi quantum dot grown on Si(113) by Si molecular beam epitaxy has been studied by transmission electron microscopy and atomic force microscopy.Photoluminescence from the as-grown sample and annealed sample was studied.The res
VISCOUS FINGERING IN SELF-AFFINE SIERPINSKI CARPET
Authors: TIAN JU-PING  , YAO KAI-LUN  ,   (1)华中理工大学物理系，武汉  430074；江汉石油学院基础科学系，荆州  434102; (2)华中理工大学物理系，武汉  430074；中国科学院国际材料物理中心，沈阳  110015；中国高等科学技术中心(世界实验室)，北京  100080
Published: November 2020

In this paper, the self-affine Sierpinski carpet is constructed. The viscous fingering (VF) in self-affine Sierpinski carpet, based on the assumption that bond radii are truncated Rayleigh distribution, is simulated by means of successive over-relaxation techniques. The fractal dimension of VF is calculated. The results show that the VF pattern of self-affine Sierpinski carpet in the limit viscosity ratio M→∞ is found to be similar to the DLA pattern. When M=1, the interior of the cluster of the displacing fluid is compact and the displacement process is stable for long length scales.
CONTROLLING OF THE UNSTABLE STATE IN OPTICAL BISTABLE SYSTEM
Authors: LIU YAO-WEN  , ZHAO HONG  , WANG YING-HAI  ,   兰州大学物理系，兰州  730000
Published: November 2020

Using a very easy and very convenient method, we controlled the unstable intermediate state of the hysteresis loop in an optical bistable system governed by a delay differential equation. Simultaneously, we also stabilized and suppressed the Hopf bifurcation and double-period bifurcation by this technique. All the numerical results are obtained by simulating the experimental condition of Gibbs et al.
OBSERVATIONS OF SPECTRA OF ATOMIC BEAM IN A SLOW-WAVE FIELD
Authors: LI FO-SHENG  , CAI WEI-QUAN  , WANG YU-ZHU  ,   中国科学院上海精密光学机械研究所量子光学开放实验室，上海  201800
Published: November 2020

This article demonstrates some important characteristics of the slow-wave spectra; the Doppler broadening varies with the geometrical parameters of slow-wave structures. Several experimental standing slow-wave spectra was given under different conditions. The influence of magnetic field on the spectra was also discussed.
EFFECTS OF FLUCTUATION OF FREE ELECTRONS ON PHOTOIONIZATION CROSS-SECTION NEAR THRESHOLD
Authors: ZHENG MIN  , MENG XU-JUN  , SUN YONG-SHENG  ,   (1)北京应用物理与计算数学研究所，北京  100088; (2)湛江教育学院物理系，湛江  524037
Published: November 2020

Based on relativistic HFS self-consistent field average atomic model, the effect of the fluctuation of free electrons on the threshold of photoionization in local thermal equilibrium plasmas is studied by employing the principle of entropy in grand-canonical ensemble. Some results are discussed.
GENERAL FORMULAS FOR RADIAL MATRIX ELEMENTS OF ISOTROPIC HARMONIC OSCILLATORS
Authors: HOU CHUN-FENG  , SUN XIU-DONG  , ZHOU ZHONG-XIANG  , LI YAN  ,   哈尔滨工业大学物理系，哈尔滨  150001
Published: November 2020

The general formulas for radial matrix elements p|n′l′> and q|n′m′> of three-dimensional and two-dimensional isotropic harmonic oscillators are derived-
MICROSTRUCTURE AND ABSORPTION SPECTRA OF (Ag,Au)/Si NANOCOMPOSITE FILM
Authors: WANG QU-QUAN  , ZHAO TONG-YUN  , YANG BAI-FENG  , NIU FENG  , ZHOU ZHENG-GUO  , XIONG GUI-GUANG  , TIAN DE-CHENG  ,   (1)Department of Materials,University of Oxford,Oxford OX1 3pH,U.K.; (2)武汉大学物理系，武汉  430072; (3)武汉大学物理系，武汉  430072；武汉工业大学材料复合新技术国家重点实验室，武汉  430070; (4)武汉大学物理系，武汉  430072；中国科学院国际材料物理中心，沈阳  110015
Published: November 2020

(Ag,Au)/Si nanocomposite films were deposited using the rf co-sputtering method. The absorption coefficient of Ag/Si nanocomposite film was calculated based on the Maxwell-Garnett theory and differential effective medium(DEM) theory;the experimental results of spectra agreed with the DEM theory.And the possible microstructure and the reason why the plasma resonance absorption peaks were broadened have been discussed.
STUDY ON PLASMA ETCHING OF β-SiC THIN FILMS IN SF6 AND THE SF6+O2 MIXTURES
Authors: CHAI CHANG-CHUN  , YANG YIN-TANG  , LI YUE-JIN  , JIA HU-JUN  , JI HUI-LIAN  ,   西安电子科技大学微电子研究所，西安  710071
Published: November 2020

Plasma etching(PE) of cubic β-SiC single crystalline thin films produced via chemical vapor deposition(CVD) has been performed in SF6 and the SF6+O2 mixtures. Experimental results show that the maxima of etching rate are reached when gas mixing ratio is about 40%. The Auger energy spectra indicate that PE process in SF6 and the SF6+O2 mixtures does not yield a residual SiC with a C-rich surface. This technique and experimental results may serve as the foundation of fabricating various devices of SiC.
RADIATING OF ACCELERATING CHARGE IN GENERAL RELATIVITY
Authors: TANG ZHI-MING  , WANG YONG-JIU  ,   湖南师范大学物理研究所，长沙  410081
Published: November 2020

Based on the previous paper, for accelerating charge in general relativity, we obtained the exact expressions of electromagnetic field and radiating energy.
CONTROLLING HYPERCHAOS THROUGH LENGTHENING TIME OF AUTOCORRELATION OF SIGNAL
Authors: LUO XIAO-SHU  , FANG JIN-QING  , QU WAN-LI  ,   (1)广西师范大学物理与电子科学系，桂林  541004; (2)华中理工大学电信系，武汉  430074; (3)中国原子能科学研究院，北京  102413
Published: November 2020

The method of Lengthening time of autocorrelation of signal is used to control hyperchaotic behavior in nonlinear continuous system. The Rossler and CLHE hyperchaotic system are taken as two typical examples. The numberical simulations show that the behavior of hyperchaos in a nonlinear system is controlled effectively and a series of stable periodic orbits are obtained by the method in this paper. The choice of control parameter is independent of controlled hyperchaotic systems in principle.
THE STABILITY OF A STATIC BLACK-HOLE WITH MASS MULTIPOLE MOMENT
Authors: PENG FAN-ZHI  , LIU LIAO  ,   北京师范大学物理系，北京 100875
Published: November 2020

By studying the Hawking radiation near the horizon of a static black-hole with a multipole moment, we find that its existence would violate thermodynamic laws of black-hole. Under a perturbation of dust, this kind of gravitational field is unstable. So we guess that this kind of black-hole does not likely exist in the universe.
EPITAXIALL GROWTH OF CUBIC AND HEXAGONAL GaN FILMS ON GaAs(001) SUBSTRATES BY MBE
Authors: LIU HONG-FEI  , CHEN  HONG  , LI ZHI-QIANG  , WAN LI  , HUANG QI  , ZHOU JUN-MING  , LUO  YI  , HAN  YING-JUN  ,   (1)清华大学电子工程系，北京  100084; (2)中国科学院物理研究所，北京  100080
Published: November 2020

GaN films of about 300nm were grown on GaAs(001) substrates by molecular beam epitaxy (MBE).X-ray double-crystal diffraction and room-temperature photoluminescence measurements show that the films grown on nitridized GaAs nucleation layer are pure cubic GaN while the films grown on nitridized AlAs nucleation layer are pure hexagonal GaN.The present study shows that the phase of GaN samples grown on GaAs substrates can be controlled using different nucleation layers
Studies on Many－Body Interactions and Molecular Dynamics Simulations for the Hugoniot Curves of Liquid Argon
Authors: Wang Fan－ hou  , Yang Chuan－lu  , Li Xi－jun  , Jing Fu－qian  ,   (1)四川大学原子与分子物理研究所，成都　610065; (2)中国工程物理研究院流体物理研究所爆轰物理与冲击波物理实验室，绵阳　621900
Published: November 2020

Because of the fundamental nature of condensed rare gases　their potentials and e quations of state have been studied extensively in recent years.In the present w ork　based on ab initio calculations on many－body interactions　the MSVⅢ potenti al proposed by Parson et al.for argon system has been modified　and the molec ula r dynamics method is employed to calculate the Hugoniot curve for liquid argon s ystem.Comparisons are performed between theoretical Hugoniot curve and the exper imental measurements.This demonstrates that the coincidence degree between the t heoretical and the experimental results is significantly improved.
A STUDY OF NO.2 SERIES ZrO2(Y2O3) THIN FILM BY SLOW POSITRONS BEAM
Authors: ZOU LIU-JUAN  , XIA FENG  , ZOU DAO-WEN  , WENG HUI-MIN  , HUANG QIAN-FENG  , ZHOU XIAN-YI  , HAN RONG-DIAN  ,   (1)华中理工大学物理系，武汉  430074; (2)江西师范大学物理系，南昌  330027; (3)中国科学技术大学现代物理系，合肥  230026
Published: November 2020

The ZrO2(Y2O3) thin film materials are studed b y slow positron beam.The ZrO2(Y2O3) thin film m aterials are made by r f puttering without biasing,heat treatment of liner being at 300℃ in pure Ar atmosphere.We discovered that the defects distribute themse lves in different depths of the thin film.The tempearture influences the distril ution of defects in the YSZ thin films.And we discuss briefly the method to make dense and high-quality YSZ films.
LONGITUDINAL ELECTRO-OPTIC MODULATION USING POLED POLYMER FILMS IN A FABRY-PEROT CAVITY
Authors: CHEN KAI-XIN  , YI MAO-BIN  , ZHANG DA-MING  , HOU A-LIN  ,   集成光电子学国家重点联合实验室吉林大学实验区，长春  130023
Published: November 2020

Longitudinal Electro-optic modulation has been demonstrated using poled electro-optic polymer films placed in a Fabry-Perot(F-P) cavity, in which the directions of the poling electric field, the applied electric field and the light traveling are parallel with each other, and perpendicular to the surface of the polymer film. The F-P cavity used here had a fineness of about 18. The thickness of polymer films is about 1μm. The modulation depth about 0.012%, was achieved, in a low ac field of 1V/μm. The results demonstrate that it is possible to achieve electro-optic modulation of poled polymer films and to study the films using F-P cavity.
EFFECT OF THE MAGNETIC MIRROR FIELD ON THE ION ENERGY DISTRIBUTIONS IN A RADIO F REQUENCY PLASMA
Authors: LIU HONG-XIANG  , WEI HE-LIN  , LIU ZU-LI  , LIU YAN-HONG  , WANG JUN-ZHEN  ,   华中理工大学物理系，武汉  430074
Published: November 2020

In this article, using the retarding grid energy analyzer, we have measured the ion energy distributions in a low temperature radio fruquency plasma under the condition of different magnetic mirror parameters. At the centre of discharge cell, the ion energy distributions displace in the direction of low energy with the increase of the magnetic density without evident variation in the ion energy distribution width. With the increase of the magnetic mirror ratio, the ion energy distribution displaces in the direction of high energy, and the width of ion energy distribution became wider. So the magnetic mirror parameters have significant effect on the ion energy distributions.
Control of Chaotic Lorenz System to Approach any Desired Targets With Feedback Functions
Authors: Tang Guo－ning  , Luo Xiao－shu  , Kon g Ling－jiang  ,   广西师范大学物理与电子科学系,桂林541004
Published: November 2020

This paper investigates the methods for controlling chaos in the Lorenz system with nonlinear feedback functions. Feedback functions and results of controlling-chaos are presented through theoretical analysis. The results of theory and num erical calculations indicate that the trajectories of a chaotic system can be co ntrolled to approach the target periodic orbits or points by feedback functions.
Study on Microstructure Evolution and Liquid－Solid Correlation of Pur e Aluminum Melts
Authors: Wang Li  , Li Hui  , Bian Xiu－fang  , Sun  Min－hua  , Liu Xiang－fa  , Liu Hong－bo  , Chen Kui－ying  ,   (1)山东工业大学材料学院,济南250061; (2)中国科学院金属研究所,沈阳110015
Published: November 2020

The molecular dynamics simulations have been performed on microstructure and tra n sfer mechanism of liquid Al. The pair distributed function has been attained at different temperatures and cooling rates by means of tight－binding potential. T he proportions of small atom groups of different types have been analyzed by ado pting bond pair index method. The result indicates that if the cooling rate is l ow　 crystals will be formed　otherwise　amorphism will occur under relatively hi gh cooling rate. When the liquid Al forms crystal　the bond pairs 1421　1422 play an important role　 while the pairs 1551　1541 have the close connection with the formation of amorphism.
Quantitative Study of Improvements of the Imaging Contrast and Imaging Range by the Polarization Technique
Authors: Cao Nian－wen  , Liu Wen－qing  , Zhang Yu－jun  ,   中国科学院安徽光学精密机械研究所，合肥　230031
Published: November 2020

The relation between the polarization technique and the enhance for the image contrast and the imaging range has been reported in this paper.The equati on expressing the image contrast and the imaging range is calculated and the exp erimental data is acquired.The experimental data agree with the calculated resu lt.It is shown quantitatively that the polarization technique improves the image contrast and imaging range greatly.
Displaced Excited Squeezed Vacuum States and Their Propertities
Authors: Sun Zhi－hu  , Fan Hong－yi  ,   中国科学技术大学材料科学与工程系，合肥　230026
Published: November 2020

We introduce the states D(z)a\+\{+\+m\}S(r)|0〉 and examine their properties . Such states are checked to be complete vectors via the IWOP (Integration W ithin an Ordered Product of operators) technique. We find larger－scale macrosco pic oscillations of photon distribution after the squeezed vacuum states being e xcited and displaced. On contrary to the bunching photons of the squeezed vacuum states　 as the displacing parameter |z| and the excitation number m are both small　 photons coherence can exhibit antibunching effect. The quasi－proba bility distribution functions (Husimi Q( 　醆+*) function and Wigner W(q　 p) function) are derived and their dependences on the three parameters (z　m　 r) are discussed. The Wigner function obviously displays their nonclassical fe ature.
Experimental Research on Generation of Intensity Squeezed Light at 532 ?nm by SHG
Authors: Zhang Kuan－shou  , Zhang Jing  , Xie Chang－de  , Peng Kun－chi  ,   山西大学光电研究所，太原　030006
Published: November 2020

Considering the noise characteristics of the pump source　the noise spectra of ou tput harmonic field from the singly resonant frequency doubler is derived by mea ns of the motion equations for SHG.The intensity noise squeezing of 20% has been measured from the stable SH wave output.(It is in accordence with the squeezing of 30% if the efficiency of detection system is taken into account).The maximum squeezing measured experimentally is in agreement with the theoretical predicti ons.
EHMT2 epigenetically suppresses Wnt signaling and is a potential target in embryonal rhabdomyosarcoma
Authors: Pal Ananya , Leung Jia Yu , Ang Gareth Chin Khye , Rao Vinay Kumar , Pignata Luca , Lim Huey Jin , Hebrard Maxime , Chang Kenneth TE , Lee Victor KM , Guccione Ernesto , Taneja Reshma
Published: November 2020

Wnt signaling is downregulated in embryonal rhabdomyosarcoma (ERMS) and contributes to the block of differentiation. Epigenetic mechanisms leading to its suppression are unknown and could pave the way toward novel therapeutic modalities. We demonstrate that EHMT2 suppresses canonical Wnt signaling by activating expression of the Wnt antagonist DKK1. Inhibition of EHMT2 expression or activity in human ERMS cell lines reduced DKK1 expression and elevated canonical Wnt signaling resulting in myogenic differentiation in vitro and in mouse xenograft models in vivo. Mechanistically, EHMT2 impacted Sp1 and p300 enrichment at the DKK1 promoter. The reduced tumor growth upon EHMT2 deficiency was reversed by recombinant DKK1 or LGK974, which also inhibits Wnt signaling. Consistently, among 13 drugs targeting chromatin modifiers, EHMT2 inhibitors were highly effective in reducing ERMS cell viability. Our study demonstrates that ERMS cells are vulnerable to EHMT2 inhibitors and suggest that targeting the EHMT2-DKK1-β-catenin node holds promise for differentiation therapy.
Glutamine metabolism modulates azole susceptibility in Trypanosoma cruzi amastigotes
Authors: Dumoulin Peter C , Vollrath Joshua , Tomko Sheena Shah , Wang Jennifer X , Burleigh Barbara
Published: November 2020

The mechanisms underlying resistance of the Chagas disease parasite, Trypanosoma cruzi, to current therapies are not well understood, including the role of metabolic heterogeneity. We found that limiting exogenous glutamine protects actively dividing amastigotes from ergosterol biosynthesis inhibitors (azoles), independent of parasite growth rate. The antiparasitic properties of azoles are derived from inhibition of lanosterol 14α-demethylase (CYP51) in the endogenous sterol synthesis pathway. We find that carbons from 13C-glutamine feed into amastigote sterols and into metabolic intermediates that accumulate upon CYP51 inhibition. Incorporation of 13C-glutamine into endogenously synthesized sterols is increased with BPTES treatment, an inhibitor of host glutamine metabolism that sensitizes amastigotes to azoles. Similarly, amastigotes are re-sensitized to azoles following addition of metabolites upstream of CYP51, raising the possibility that flux through the sterol synthesis pathway is a determinant of sensitivity to azoles and highlighting the potential role for metabolic heterogeneity in recalcitrant T. cruzi infection.
Hydrodynamics of sponge pumps and evolution of the sponge body plan
Authors: Asadzadeh Seyed Saeed , Kiørboe Thomas , Larsen Poul Scheel , Leys Sally P , Yahel Gitai , Walther Jens H
Published: November 2020

Sponges are suspension feeders that filter vast amounts of water. Pumping is carried out by flagellated chambers that are connected to an inhalant and exhalant canal system. In ‘leucon’ sponges with relatively high-pressure resistance due to a complex and narrow canal system, pumping and filtering are only possible owing to the presence of a gasket-like structure (forming a canopy above the collar filters). Here, we combine numerical and experimental work and demonstrate how sponges that lack such sealing elements are able to efficiently pump and force the flagella-driven flow through their collar filter, thanks to the formation of a ‘hydrodynamic gasket’ above the collar. Our findings link the architecture of flagellated chambers to that of the canal system, and lend support to the current view that the sponge aquiferous system evolved from an open-type filtration system, and that the first metazoans were filter feeders.
The mechanism of kinesin inhibition by kinesin-binding protein
Authors: Atherton Joseph , Hummel Jessica JA , Olieric Natacha , Locke Julia , Peña Alejandro , Rosenfeld Steven S , Steinmetz Michel O , Hoogenraad Casper C , Moores Carolyn A
Published: November 2020

Subcellular compartmentalisation is necessary for eukaryotic cell function. Spatial and temporal regulation of kinesin activity is essential for building these local environments via control of intracellular cargo distribution. Kinesin-binding protein (KBP) interacts with a subset of kinesins via their motor domains, inhibits their microtubule (MT) attachment, and blocks their cellular function. However, its mechanisms of inhibition and selectivity have been unclear. Here we use cryo-electron microscopy to reveal the structure of KBP and of a KBP–kinesin motor domain complex. KBP is a tetratricopeptide repeat-containing, right-handed α-solenoid that sequesters the kinesin motor domain’s tubulin-binding surface, structurally distorting the motor domain and sterically blocking its MT attachment. KBP uses its α-solenoid concave face and edge loops to bind the kinesin motor domain, and selected structure-guided mutations disrupt KBP inhibition of kinesin transport in cells. The KBP-interacting motor domain surface contains motifs exclusively conserved in KBP-interacting kinesins, suggesting a basis for kinesin selectivity.
The integration of Gaussian noise by long-range amygdala inputs in frontal circuit promotes fear learning in mice
Authors: Aime Mattia , Augusto Elisabete , Kouskoff Vladimir , Campelo Tiago , Martin Christelle , Humeau Yann , Chenouard Nicolas , Gambino Frederic
Published: November 2020

Survival depends on the ability of animals to select the appropriate behavior in response to threat and safety sensory cues. However, the synaptic and circuit mechanisms by which the brain learns to encode accurate predictors of threat and safety remain largely unexplored. Here, we show that frontal association cortex (FrA) pyramidal neurons of mice integrate auditory cues and basolateral amygdala (BLA) inputs non-linearly in a NMDAR-dependent manner. We found that the response of FrA pyramidal neurons was more pronounced to Gaussian noise than to pure frequency tones, and that the activation of BLA-to-FrA axons was the strongest in between conditioning pairings. Blocking BLA-to-FrA signaling specifically at the time of presentation of Gaussian noise (but not 8 kHz tone) between conditioning trials impaired the formation of auditory fear memories. Taken together, our data reveal a circuit mechanism that facilitates the formation of fear traces in the FrA, thus providing a new framework for probing discriminative learning and related disorders.
Presynaptic NMDARs cooperate with local spikes toward GABA release from the reciprocal olfactory bulb granule cell spine
Authors: Lage-Rupprecht Vanessa , Zhou Li , Bianchini Gaia , Aghvami S Sara , Mueller Max , Rózsa Balázs , Sassoè-Pognetto Marco , Egger Veronica
Published: November 2020

In the rodent olfactory bulb the smooth dendrites of the principal glutamatergic mitral cells (MCs) form reciprocal dendrodendritic synapses with large spines on GABAergic granule cells (GC), where unitary release of glutamate can trigger postsynaptic local activation of voltage-gated Na+-channels (Navs), that is a spine spike. Can such single MC input evoke reciprocal release? We find that unitary-like activation via two-photon uncaging of glutamate causes GC spines to release GABA both synchronously and asynchronously onto MC dendrites. This release indeed requires activation of Navs and high-voltage-activated Ca2+-channels (HVACCs), but also of NMDA receptors (NMDAR). Simulations show temporally overlapping HVACC- and NMDAR-mediated Ca2+-currents during the spine spike, and ultrastructural data prove NMDAR presence within the GABAergic presynapse. This cooperative action of presynaptic NMDARs allows to implement synapse-specific, activity-dependent lateral inhibition, and thus could provide an efficient solution to combinatorial percept synthesis in a sensory system with many receptor channels.
A hybrid method for heartbeat classification via convolutional neural networks, multilayer perceptrons and focal loss
Authors: Wang Tao , Lu Changhua , Yang Mei , Hong Feng , Liu Chun
Published: November 2020

Background

Heart arrhythmia, as one of the most important cardiovascular diseases (CVDs), has gained wide attention in the past two decades. The article proposes a hybrid method for heartbeat classification via convolutional neural networks, multilayer perceptrons and focal loss.

Methods

In the method, a convolution neural network is used to extract the morphological features. The reason behind this is that the morphological characteristics of patients have inter-patient variations, which makes it difficult to accurately describe using traditional hand-craft ways. Then the extracted morphological features are combined with the RR intervals features and input into the multilayer perceptron for heartbeat classification. The RR intervals features contain the dynamic information of the heartbeat. Furthermore, considering that the heartbeat classes are imbalanced and would lead to the poor performance of minority classes, a focal loss is introduced to resolve the problem in the article.

Results

Tested using the MIT-BIH arrhythmia database, our method achieves an overall positive predictive value of 64.68%, sensitivity of 68.55%, f1-score of 66.09%, and accuracy of 96.27%. Compared with existing works, our method significantly improves the performance of heartbeat classification.

Conclusions

Our method is simple yet effective, which is potentially used for personal automatic heartbeat classification in remote medical monitoring. The source code is provided on https://github.com/JackAndCole/Deep-Neural-Network-For-Heartbeat-Classification.
A Bayesian brain model of adaptive behavior: an application to the Wisconsin Card Sorting Task
Authors: D’Alessandro Marco , Radev Stefan T. , Voss Andreas , Lombardi Luigi
Published: November 2020

Adaptive behavior emerges through a dynamic interaction between cognitive agents and changing environmental demands. The investigation of information processing underlying adaptive behavior relies on controlled experimental settings in which individuals are asked to accomplish demanding tasks whereby a hidden regularity or an abstract rule has to be learned dynamically. Although performance in such tasks is considered as a proxy for measuring high-level cognitive processes, the standard approach consists in summarizing observed response patterns by simple heuristic scoring measures. With this work, we propose and validate a new computational Bayesian model accounting for individual performance in the Wisconsin Card Sorting Test (WCST), a renowned clinical tool to measure set-shifting and deficient inhibitory processes on the basis of environmental feedback. We formalize the interaction between the task’s structure, the received feedback, and the agent’s behavior by building a model of the information processing mechanisms used to infer the hidden rules of the task environment. Furthermore, we embed the new model within the mathematical framework of the Bayesian Brain Theory (BBT), according to which beliefs about hidden environmental states are dynamically updated following the logic of Bayesian inference. Our computational model maps distinct cognitive processes into separable, neurobiologically plausible, information-theoretic constructs underlying observed response patterns. We assess model identification and expressiveness in accounting for meaningful human performance through extensive simulation studies. We then validate the model on real behavioral data in order to highlight the utility of the proposed model in recovering cognitive dynamics at an individual level. We highlight the potentials of our model in decomposing adaptive behavior in the WCST into several information-theoretic metrics revealing the trial-by-trial unfolding of information processing by focusing on two exemplary individuals whose behavior is examined in depth. Finally, we focus on the theoretical implications of our computational model by discussing the mapping between BBT constructs and functional neuroanatomical correlates of task performance. We further discuss the empirical benefit of recovering the assumed dynamics of information processing for both clinical and research practices, such as neurological assessment and model-based neuroscience.