bluuebunny/crossref_metadata_2025 huggingface dataset:
THE MULTI-PHOTON QUANTUM STATISTICAL THEORY OF DRIVEN OPTICAL SYSTEMS (Ⅲ)——IMPROVEMENT OF THE METHOD OF ADIABATIC ELIMINATION
Authors: LIN REN-MING  , ZHANG LIN  ,   福建师范大学物理系
Published: November 2020

In this paper, we discuss the multi-photon systems by employing the method of adiabatic elimination following the procedure of Lugiato. We come to the conclusion that, in both the "good cavity case" and the "bad cavity case", the result we get from the discussion contains the result drawn by the adiabatic elimination following the procedure of Gordon. More over, it can compute directly the correlation of the variable that has been adiabatically eliminated. Particularly in the "bad cavity case", the steady state value of the field variable correlation obtained by the method of Lugiato is different from that obtained by the method of Gordon. The method of Lugiato is self-consistent so it is much better.In the appendix, the formulae of the atomic squeezing and the multi-photon spectrum of transmitted light are presented.
THE EFFECTS OF ACCELERATION DRIVEN BY LOWER-HYBRID WAVES
Authors: XIA MENG-FEN  , WU WEI-MIN  ,   北京大学物理系
Published: November 2020

There is an acceleration term in the generalized Fokker-Planck equation, which describes the ourrent generation and the radial motion of electrons driven by lower-hybrid waves. The effects of the acceleration on the evolution of the distribution function, the coupling mechanism between the waves and the electrons and the wave-driven radial transport are discussed.
STABILITY OF COLLISIONLESS DRIFT WAVES IN A HOT ELECTRON PLASMA
Authors: HUANG CHAO-SONG  , WU GUANG-XUE  , XIAO SHI-LI  ,   (1)中国科学院等离子体物理研究所; (2)中南民族学院物理系
Published: November 2020

The low frequency interchange mode and d ift wave in a hot electron plasma are analyzed by using the Vlasov equation, and the effect of hot electrons is discussed. The stabilization of the drift wave occurs when α～30%, and the stabilization of the interchange mode occurs when α～10%, where a is the fraction of hot electrons. The influences of ion Larmor radius, density gradient and temperature of plasma, wavelength of perturbation, and magnetic curvature, on the stability are discussed. Comparing with the results of the strongly collisional drift wave derived from the MHD approximation, the collisionless drift wave can be stabilized by the ho electrons more easily.
BRILL OUIN AND RAMAN SCATTERING FROM LIQUID MIXTURES
Authors: ZHU DAN  , ZHANG PENG-XIANG  , ZHOU ZHONG-BI  , YANG JIANG-GUO  ,   (1)四川大学物理系; (2)中国科学院物理研究所
Published: November 2020

Liquid mixtures were studied by Brillouin and Raman Scattering. The curves of sound velocity vs. mixture ratio demonstrate various behaviours, some show monotonous change, others show maximum or minimum. From Raman spectrums, we found that some molecular vibration frequencies are shifted by mixing. We explained these phenomena and got informations about molecular interactions in the mixtures.
AN XPS STUDY ON Y-Ba-Cu-Al-O SYSTEM
Authors: ZHANG HAN  , HE ZHEN-HUI  , ZHAO YONG  , SUN SHI-FANG  , QIAN YI-TAI  , ZHANG QI-RUI  ,   (1)中国科学技术大学物理系; (2)中国科学技术大学应用化学系
Published: November 2020

The XPS, oxygen content and resistance-temperature relationship of YBa2Cu3-xAlxO7-y single phase system are determined. The experimental results show that Al can possibly substitute the Cu and Y positions in 1-2-3-phase partially. Because of the existence of Al3+, the content of oxygen increases, the environment of oxygen tends to be uniform, the difference of the two states of O15 in XPS is indistinct. The presence of Cu3+ is clearly observed.
MICROWAVE PREIONIZATION PLASMA IN A TOKAMAK
Authors: WANG LONG  , LUO YAO-QUAN  , LI ZAN-LIANG  , WANG WEN-SHU  , YANG SI-ZE  , LI WEN-LAI  , QI XIA-ZHI  , ZHAO HUA  ,   中国科学院物理研究所
Published: November 2020

A currentless plasma has been obtained in a tokamak device using a powerful microwave at electron cyclotron frequency generated by gyrotron systems. Its electron density is up to 8×1012cm-3; the electron temperature is up to 50 eV; the particle confinement time is about. 0.5ms; the heating efficiency is above 25%. The effect of the plasma on the toroidal breakdown and the heating mechanism have been studied.
THE MECHANISM OF HIGH TEMPERATURE CREEP ASSOCIATED WITH THE CLIMB OF EXTENDED DISLOCATIONS
Authors: LI YONG  , KONG QING-PING  ,   中国科学院固体物理研究所
Published: November 2020

The mechanism of high temperature creep associated with the climb of extended dislocations is investigated. Based on the model for the contraction of extended jogs [1], the time needed for the contraction under the action of applied stress and the climb velocity of extended dislocations are derived. And consequently, an expression of the steady state creep rate is obtained. According to this expression, the creep rate is shown to be proportional to the third power of the stacking fault energy. This is consistent with the majority of experimental results. The possible reason for the deviation from the third power relation in some cases is also discussed.
NONLINEAR PROPERTIES OF FOUR-LEVER ATOM INTERACTING WITH TWO-MODE CAVITY FIELDS
Authors: LIU ZHENG-DONG  ,   江西师范大学物理系
Published: November 2020

This paper studies the interaction of a four-lever cascade atom with two-mode cavity fields in which the lower mode is initially empty. It is shown that there exist long time dipper squeezing and alternate squeezing, as well as strong antibunching and superbunching. The relation between the squeezing and superbunching is disclosed, the nonclassical squeezing and antibunching may occur at the same time. This nonlinear properties originate from the effect of complicated superposition states.
CALCULATION OF ALKALI MATEL INDUCED Cu(110)-(l×2) RECONSTRUCTED SURFACE BY LAYER DOUBLING METHED
Authors: HU ZI-PU  , PAN BI-CAI  , W. C. FAN  ,   (1)美国休斯顿大学物理系; (2)中国科学技术大学材料科学系,合肥,230026
Published: November 2020

The layer doubling method of dynamic calculation of Low Energy Electron Diffraction is introduced. It was used to analyse the reconstruction of Cu(110)-(l×2) surface induced by adsorption of alkali metals. The result shows that missing row model with top layer spacing contracted to 1.13? is the most reliable structure.
CONFINED SUBBAND—CONTINUUM TRANSITIONS IN STRAINED LAYER In0.15Ga0.85As-GaAs MULTIPLE QUANTUM WELLS
Authors: FANG XIAO-MING  , SHEN XIE-CHU  , HOU HONG-QI  , FENG WEI  , ZHOU JUN-MIN  ,   (1)中国科学院上海技术物理研究所红外物理开放研究实验室,上海,200083; (2)中国科学院物理研究所,北京,100080
Published: November 2020

The influence of steady LED irradiation on the photocurrent spectra of the strained layer multiple quantum wells In0.15Ga0.85 As (8nm)-GaAs (15nm) with 15 periods have been studied from 10 K to 300 K. The photocurrent peaks corresponding to various transitions decrease in different ways with the increase of LED irradiation intensity. By this means, the transitions from confined subband to continuum can be identified easily, and the conduction- and valence-band edge discontinuity has been determined directly from the experimental energy values of various transitions. Consequently, the band offset of heavyhole valence band is obtained as Qv = 0.38±0.01.
DISCUSSION ABOUT THE RELATION OF POSITION BETWEEN GRAVITATIONAL WAVES DETECTORS AND THE SOURCE
Authors: ZHENG QING-ZHANG  , TANG MENG-XI  , HU EN-KE  ,   中山大学物理系,广州,510275
Published: November 2020

Starting from calculating the directivity pattern of bar-shaped gravitational wave antenna, the relation of position between gravitational waves detectors and source is discussed in this paper. Further, the methods, which is used to determine the position of gravitational wave source, based on the data of coincident experiments, and the position of continuous gravitational wave source, based on the data of single gravitational wave antenna, are obtained. These results are also applicable for other types of one-dimentional gravitational wave detector. Once the sensitivity of the gravitational wave detector reaches the level, enough to determine the intensity of gravitational wave, the results presented in this paper will undoubtedly be useful for gravitational wave astronomy in the future.
TRANSFORMATION BETWEEN TAUPIN'S AND TAKAGI'S EQUATIONS AND THE PHYSICAL IMPLICATION
Authors: HE CHU-GUANG  , MAI ZHEN-HONG  , CUI SHU-FAN  ,   中国科学院物理研究所,北京,100080
Published: November 2020

The transformation between Taupin's and Takagi's equations of X-ray dynamical theory in the case of distorted crystal is investigated. The physical implication of this transformation is presented. It is considered that the difference between these two quations is due to the different choice of the wave vector k0 but the function of these two equations is equivalent.
A STUDY ON MOVING SCREW DISLOCATION BY THE METHOD OF GAUGE FIELD THEORY FOR CRYSTAL DEFECTS
Authors: GAO FEI  , YANG SHUN-HUA  ,   (1)北京科技大学材料物理系,北京,100083; (2)兰州大学材料科学系,兰州,730001
Published: November 2020

In this paper, the gauge field theory of crystal defects is applied to analyse the characteristics of moving screw dislocation. The dynamic equations of screw dislocation are solved under certain gauge condition and the stress fields of uniformly moving screw dislocation are obtained. When K = μ/s (x is the coupling constant) approaches zero, the form of stress fields tends to be the same as that of uniformlymoving Volterra dislocation, but the limiting velocity happens to be 21/2c. When the velocity of this dislocation is zero, the stress are the same as that of Volterra dislocation at rest. Finally, the results are discussed in brief.
DOPING AND ELECTRICAL CONDUCTIVITY IN HALOGEN-BRIDGED MIXED-VALENCE PLATINUM COMPLEX
Authors: PENG JING-CUI  ,   湖南大学应用物理系,长沙,410082
Published: November 2020

A model Hamiltonian is presented to describe halogen-bridged mixed-valence platinum complex (HMPC), the Green function is used to calculate the electrical conductivity of doping HMPC, the dope induced defect states are discussed in detail, the results are in agreement with experiments satisfactorily.
AUGER DEPTH PROFILE ANALYSIS OF GexSi1-x/Si SUPERLATTICE
Authors: WEI XING  , JIANG WEI-DONG  , ZHOU GUO-LIANG  , YU MING-REN  , WANC XUN  ,   复旦大学表面物理实验室,上海,200433
Published: November 2020

The compositional depth profile of GexSi1-x/Si strained layer superlattice has been obtained by AES combined with argon ion sputtering, which indicates the concentrations of Ge and Si vary with depth periodically. The secondary electron image shows some periodic pattern consisting of alternate bright and dark bands around the center of the sputtered crater. The characteristics of Auger depth profile as a method for superlattice structure analysis, as well as its limitations, are discussed.
LASER PLASMA WAVE ELECTRON ACCELERATORS
Authors: CHANG WEN-WEI  , ZHANG LI-FU  , SHAO FU-QIU  ,   国防科技大学应用物理系,长沙,410003
Published: November 2020

In this paper, we discuss the physical mechanism of laser plasma wake wave and beat wave accelerators by means of theoretical analysis and particle simulation methods. The results show that: as long as laser plasma wave has Vph≈c and is strong enough, and with a proper transverse magnetic field applied, we may accelerate relativistic electrons to the order of magnitude of GeV within a distance of meters. We have also studied the problem of ES wave with low phase velocity generated by laser plasma Raman scattering to accelerate non-relativistic electrons by using particle simulation methods, and possibility of multistage, or multiwave, acceleration is explored as well. The results show that: taking the advantage of laser plasma wave accelerator, we will be able to get high energy electrons of the order of magnitude of Gev under ordinary laboratory conditions.
X-RAY DOUBLE-CRYSTAL DIFFRACTION STUDY OF HIGH QUALITY GexSi1-x/Si STRAINED LAYER SUPERLATTICE
Authors: TIAN LIANG-GUANG  , ZHU NAN-CHANG  , CHEN JING-YI  , LI RUN-SHEN  , XU SHUN-SHENG  , ZHOU GUO-LIANG  ,   (1)复旦大学表面物理实验室,上海,200433; (2)中国科学院上海冶金研究所,上海,200050
Published: November 2020

In this paper, the analysis of GexSi1-x/Si strained layer superlattice grown by MBE is made by means of X-ray double crystal diffraction. The structure parameters of GexSi1-x/Sisuperlattice is obtained from the simulation of rocking curve based on X-ray kinematical and dynamical diffraction theory respectively. The results calculated with these two theories is almost the same, there is a little difference only in the fine structure of rocking curve. For the high quality GexSi1-x/Si superlattice, the rocking cu rve calculated with X-ray dynamical theory is more close to the experimental curve than that with X-ray kinematical theory.
FRACTAL STRUCTURE AT THE CRITICAL POINT OF CONTINUOUS PHASE TRANSFORMATION
Authors: CHEN SHI-GANG  ,   北京应用物理与计算数学研究所,北京,100088
Published: November 2020

The correlation dimensions of correlation clusters at the critical point of continuous phase transformation are studied. The correlation dimensions Dn= d-nβ/(n - l)v, the dimension of one cluster a = d-β/v and the dimension of the centres of cluster f(a)=d are derived rigorously, and their meanings are discussed.
INTERACTION BETWEEN ALKALI METAL AND CO ON Fe(110) SURFACE
Authors: BAD SHI-NING  , ZHU LI  , XU YA-BO  , LI ZHUO-ZHI  ,   浙江大学物理系,杭州,310027
Published: November 2020

The influence of coadsorbed alkali metal on the electronic structure of CO was studied by ARUPS with polarized and unpolarized light. A new peak at 6.3 eV was observed, it reflects a new orbital of CO with the presence of coadsorbed alkali atoms. A symmetry plane and an anti-symmetry plane for this orbital were found, which are paralell to the 〈001〉azimuth and 〈110〉azimuth of the crystal surface respectively. The symmetry results of CO coadsorbed with different kinds of alkali metal are the same.
CONFORMAL FIELD THEORY OF Z2 SYMMETRIC QUANTUM CHAIN
Authors: Xu Bo-wei  ,   上海交通大学物理系,上海,200030
Published: November 2020

From the energy spectrum of Z2 symmetric quantum chain with periodic boundary condition, we calculated the central charge and the anomalous scale dimensions of the systems. The results are compatible with the predicfion of the conformal field theory.
THE EFFECTS OF SECOND-ORDER IONIZATION PROCESSES ON THE PHOTOELECTRON SPECTRUM OF TWOPHOTON AUTOIONIZATION
Authors: Qu Wei-xing  , Xu Zhi-zhan  , Zhang Wen-qi  ,   中国科学院上海光学精密机械研究所,上海,201800
Published: November 2020

In this paper, the two-photon autoionization involving second-order ionization processes is investigated. The photoelectron spectra are calculated, and the effects of second-order process on the photoelectron spectra and the relation of spectra's variation with intensity of light are emphatically analyzed.
FORMATION OF Zn2 EXCIMER AND ITS EMISSION BEHAVIOR
Authors: CHENG BING-YING  , LI ZHAO-LIN  , YANG YONG-WU  , NIE QING-XIANG  , ZHANG DAO-ZHONG  ,   (1)中国高等科学技术中心(世界实验室)凝聚态物理分中心; (2)中国科学院物理研究所,北京,100080
Published: November 2020

Two emission bands of Zn2 excimers have been observed in mixture of Zn vapor and buffer gases by optically pumping Zn (4s1S0—4p3P1) resonance line. Expe rimental evidence shows that they are possibly from the same 3∑u+ upper state of Zn2 excimer, this coincides with theoretical prediction. Their temporal and temperature behaviors, and also the effect of buffer gases were studied. The upper limits of molecular formation and quenching rate were determined separately. The rescults indicate that the buffer gases dominate the molecular formation and decay process.
LASER-INDUCED FLUORESCENCE EXCITATION SPECTRUM OF CCl2 COOLED IN THE SUPERSONIC JET
Authors: CHEN YANG  , LU QING-ZHENG  , WANG DONG-QING  , SHEN LIU-SI  , WANG HONG-FEI  , ZHANG YUN-WU  , YU SHU-QIN  , MA XING-XIAO  ,   中国科学技术大学近代化学系,合肥,230026
Published: November 2020

Laser-induced fluorescence excitaion spectrum of gas-phase dichlocarbene (CC12) cooled in the supersonic jet has been observed in the range of 497-517 nm. The K-structrue of the (v1,v2,0)-(0,0,0) vibrational bands was resolved. About 80 su-bbands were assigned. v＇1= 643.5cm-1, v＇2 = 308.0cm-1 and the anharmonic costants, and (A＇-B＇) = 3.67cm-1, (A" - B") = 1.80cm-1 were obtained from the analysis of spectra.
SPIN WAVES IN A MAGNETIC SUPERLATTICE WITH SINGLE-ION UNIAXIAL ANISOTROPY
Authors: SHEN WEN-ZHONG  , LI ZHEN-YA  ,   苏州大学物理系,苏州215006
Published: November 2020

The transfer-matrix method is employed to investigate the spin waves in a magnetic super-lattice with a single-ion uniaxial anisotropy. The dispersion equation of the spin waves is obtained. The effect of anisotropy strength on the spin waves spectrum is also discussed.
AN ANALOG SIMULATION OF STOCHASTIC RESONANCE
Authors: QIN GUANG-RONG  , GONG DE-CHUN  , HU GANG  , WEN XIAO-DONG  ,   北京师范大学物理系,北京,100875
Published: November 2020

Stochastic resonance (SR) phenomena are investiged from various aspects by utilizing an electric circuit The mechanism of SR is discussed and the output signal-to-noise ratio (SNR) is measured. The signal may be extracted from strong noise due to energy transfer from noise to signal under the SR condition.
DETERMINISTIC PROPERTIES CONTAINED IN QUANTUM SYSTEMS WITH CONTINUOUS SPECTRUM
Authors: LIU QUAN-HUI  ,   湖南大学应用物理系,长沙410082
Published: November 2020

When a quantum system with continuous spectrum has a definite anergy, ordinary quantum mechanics uses a single continuous stationary state to describe its properties, the expectation values for arbitrary physical quantities are therefore either infinity or zero. In this paper we point out in the form of mathematical theorem that the system possesses new and deterministic results with evident physical meanings. Classical results for the system are the classical limit cases of these results, and the ordinarv expectation values are the statistical cases of our results.
ELECTRON CORRELATION AND TWO-DIMENSIONAL LATTICE INSTABILITY
Authors: LIU JING-NAN  , SUN XIN  ,   (1)复旦大学物理系,上海,200433;中国科学技术大学结构分析开放研究实验室,合肥,230026; (2)复旦大学物理系,上海,200433;中国科学院上海技术物理研究所红外物理国家实验室,上海,200083
Published: November 2020

Starting from the screened Coulomb electron interaction, the energy band and electron wave function of two-dimensional unstable lattice system are calculated by using the Wannier function. The effect of electron correlation on two-dimensional lattice instability is studied by means of the electron correlation function. Our results show that the electron interaction reduces the two-dimensional lattice dimerization, which is different from the one-dimensional case.
EFFECTIVE-MEDIUM THEORY FOR ELECTRICAL CONDUC-TANCE OF A TWO-PHASE COMPOSITE MEDIUM WITH ELLIPSOIDAL-INCLUSIONS
Authors: BAO KE-DA  ,   北京大学物理系,北京100871
Published: November 2020

In this paper the electrical conductance of a two-phase composite medium with ellipsoidal inclusions has been investigated by using the effective-medium theory(EMT). An anisotropic factor m is suggusted TO take account of the local anisotropy of an inhomogeneous system. A formula for calculating the effective electrical conductivity tensor in such case has been proposed. A geometrical structure factor Ii(i = x,y,z) is introduced to estimate the near field effect between the particles aggregated in the inclusions. It has been shown that there is a simple relation between the structure factor Ii and the depolarization factor ni. The calculated results based on the EMT show that prolate ellipsoid (b/a = 0.2) and oblate ellipsoid (b/a=7.5) are the two principle geometrical configurations leading to the percolation threshold c1* =0.17. A preliminary theoretical analysis informs that the common mechanism leading to the percolation by these two configurations is the formation of an 'infinite' chain-shaped cluster.
A NEW METHOD FOR CONSTRUCTING ORTHONORMAL EIGENVECTORS OF HIGH ORDER POWER OF PHOTON ANNIHILATION OPERATOR
Authors: LI FU-LI  , CHAI JIN-LIN  , ZHANG ZHI-MING  ,   西安交通大学物理系,西安,710049
Published: November 2020

In this paper, orthonormal eigenvectors of high order power of photon annihila.tion operator are constructed with N basic vectors of coherent states |aei(2π)/N n〉(n = 0,1,2, …,N-1), and squeezing and antibunching in these states are studied. The results show that squeezing appears only when N = 2 and 4 but antibunching exists for every N.
A DYNAMICAL ANALYSIS ON SOLID LASER RESONATOR
Authors: ZHANG GUANG-YIN  ,   南开大学物理系,天津,300071
Published: November 2020

In solid laser resonator the dioptric srrengh of the thermal focusing lens, 1/f, as a dynamic factor of the resonator, has great influence on the operation characters of the resonator. In this paper, using the transformatin-circie diagrammatic approach, a dynamical analysis on the stability, character of output power ami mode properly of the solid laser resonator is represented in detail. Their relations on the dynamic factor are also derived.
MOLECULAR BEAM EPITAXY GROWTH AND CHARACTERI-ZATION OF GexSi1-x/Si STRAINED-LAYER SUPERLATTICES
Authors: ZHOU GUO-LIANG  , SHENG CHI  , FAN YONG-LIANG  , JIANG WEI-DONG  , YU MING-RBN  ,   复旦大学表面物理实验室,上海,200433
Published: November 2020

GexSi1-x/Si strained-layer superlattices were grown on Si(lOO) substrates under different temperatures by molecular beam epitaxy. Methods such as reflection high energy electron diffraction, X-ray double crystal diffraction, Rutherford back scattering, transmission electron microscopy and Raman scattering have been applied to study the growth and characteristics of the GexSi1-x/Si superlattices. The result show that the optimum growth temperature are different for superlattices with different composition, the smaller the x the higher the growth temperature, and vice versa. For x = 0.1-0.6, the GexSi1-x/Si superlattices with flat interfaces, good crystal perfection and uniform periodicity can be obtained with growth temperature in the range of 400-600℃.
AMPLITUDE N-POWER SQUEEZING IN A TWO-PHOTON ABSORPTION MEDIUM
Authors: JIANG HAI-HE  , HE LIN-SHENG  ,   中国科学院安徽光学精密机械研究所,合肥230031
Published: November 2020

From the equation for the matrix elements of the field density in the two-photon process, with the aid of the generation function method, the exact analytical expressions of the amplitude N-power squeezing generating in two-photon absorption process are derived. The variation of the amplitude N-power squeezing with the diemensionless time τ, power exponent N, the phase θ and the average number of photons of the incident field are discussed. It have been shown that the amplitude N-power squeezing for different power exponents N is independent of each other, the two-photon absorption process is one of effective ways to generate the amplitude N-power squeezing.
EXACT SOLUTION OF SCHR?DINGER EQUATION WITH REFLECTIONLESS POTENTIAL WELL
Authors: ZHOU GUANG-HUI  ,   湖南师范大学物理系,长沙410006
Published: November 2020

Using a transformation of hyperbolic function, the Schr?dinger equation with reflection-less potential well is transformed into an associated-Legendre equation. Then both bound and scattering state eigenfunctions are expressed in terms of associated-Legendre polynomials and functions respectively. The exact solutions obtained in this paper are more general and systematic than some asymptotic solutions or solutions of reflectionless potential with special parameters in literatures. The normalization of the scattering state is discussed in detail.
INVESTIGATION OF ELECTRONIC STRUCTURE IN THE HYDROGEN-INDUCED STRUCTURAL TRANSITION FROM DIAMOND C(111)-(2×1) TO (1×1)
Authors: PAN BI-CAI  , XIA SHANG-DA  ,   中国科学技术大学物理系,合肥230026
Published: November 2020

The electronic structure of diamond C(111) surface during transition from (2×1) recons-truction to (1×1) structure induced by adsorbed hydrogens is studied using ab initio DV-Xα mathod in this paper. The result shows that the role of adsorbed hydrogen in the structural transition is firstly distorting the Pandey π-bond in the (2×1) reconstruction, then breaking the (SP2-hybrid + Pandey π-bond) structure and forming the sp3-hybrid bonds.
ELECTRONIC STOPPING POWER AND EFFECTIVE CHARGE OF HEAVY ION-BEAM IN HOT TARGETS
Authors: WANG YOU-NIAN  , MA TENG-CAI  , GONG YE  ,   大连理工大学三束材料改性国家重点实验室,大连116023
Published: November 2020

Using linear-response dielectric theory, we have investigated the electronic stopping power and effective charge of heavy ionbeams in hot targets. For considering the charge distribution of the electrons bound to the projectile, the theoretical model of Brandt-Kitagawa is generali-zed to the situation of hot target. In the case of low and high velocities, the analytical expres-sions of the electronic stopping power and the effective charge are obtained, respectively. For low-velocity ion, it has been shown that the values of the effective charge are increased as the values of the electron gas temperature are increased. In certain temperarure range the values of the stopping power in the hot target are increased comparing with that in the cold target. For high-velocity ions in the hydrogen plasma, the theoretical values of the stopping power obtained in present work agree very well with experimental data.
TEMPERATURE DEPENDENCE OF ELECTRIC RESISTIVITY OF Nd-Fe AMORPHOUS THIN FILMS AND ITS THERMAL STABILITY
Authors: Lü Man-qi  , A. WAGENDRISTEL  ,   (1)快凝非平衡合金国家重点实验室中国科学院国际材料物理中心,沈阳110015; (2)维也纳技术大学应用物理研究所,A-1040 Vienna
Published: November 2020

The NdxFe1-x amorphous thin films with x=0.06-0.80 were prepared at 77 K by flash evaporation. The results show that the amorphous films are stable at room temperature when 0.192 and T untill the crystallization occurs. The crystallization of the amorphous films can not be completed at a certain fixed temperature but over a temperature range.
KINETIC COUPLING MODE THEORY OF THE FLAT TYPE OF CFEL LOADING DIELECTRIC WITH WIGGLER
Authors: HE YI-PING  , CHEN DE-MING  , LIU YONG-GUI  , LI CHUAN-LU  ,   国防科技大学应用物理系,长沙410073
Published: November 2020

In this paper, the flat type of CFEL partialy loading dielectric with wiggler is studied using two dimensional kinetic coupling mode theory of three waves. It is shown that the system for arbitary thickness of dielectric can generate short wavelength coherent radiation by using low energy electron beam. Suitably choosing the system parameters, the growth rate of the kind of CFEL may be much higher than general FEL and CFEL. It is also shown that the main mode of super radiation in the system is LSE mode.
FLUXON GENERATION BY A CURRENT PULSE IN JOSEPHSON JUNCTIONS──THEORY AND SIMULATIONS
Authors: WANG QIANG-HUA  , YAO XI-XIAN  ,   南京大学物理系
Published: November 2020

The problem of fluxon generation in Josephson junctions by a current pulse is addressed, with the help of the inverse scattering transform theory. The threshold conditions for soliton (breather or fluxon) generation are obtained analytically, with respect to relevant studies in the same direction. The reliability of the theory is examined by direct numerical experiments. Fairly good agreements exist between the theory and the numerical results, particularly in the case of semi-infinitely long junctions. Practically long (L～10λ) Josephson junctions are also explored, namely, overlap, in-line and circularly-symmetric annular junctions. Explained are those factors that complicate the generation processes suck as boundary effects, stability of soliton states against the driving current, soliton return effect and the applied magnetic field (in annular junctions only). The current pulse method is shown to be effective and practical for fluxon generation in Josephson junctions.
THE EXTRAORDINARY TEMPERATURE CHARA-CTERISTICS OF TWO-BEAM COUPLING IN THE Ce: Eu: LiNbO3 CRYSTAL AND STRUCTURE PHASE TRANSFORMATION
Authors: LIU JIN-SONG  , LIANG CHANG-HONG  , AN YU-YING  , LI MING-HUA  , JIN CHAN  , XU YU-HENG  , WU ZHONG-KANG  ,   (1)哈尔滨工业大学化学系; (2)南开大学物理系; (3)西安电子科技大学技术物理系
Published: November 2020

In this paper, we report the extraordinary temperature phenomenon of two-beam coupling in the Ce: Eu: LiNbO3 crystal occuring at about 55, 70 and 110℃. The phenomenon was related to the phase transformation of the crystal structure at these temperatures. An internal electric field is induced by the phase transformation. Then, the structure of space electric charge field is varied, thereby the two-beam coupling is influenced. The formula of phase transformation electrical field (PTEF) changing with temperature is obtained by means of phenomenological method. The theoretical curve in accord with experimental one was given by using the formla and the one-carrier and one-level band-conduction model, which is in accordaace with the experimental curve. The order of the PTEF, 10５Ｖ·ｍ-1，was calculated, which is the value between the order of diffusion electric field and maximum space electric charge field and is the same as the one reported iv Ref. [7].
THE PROPERTIES OF THE MHD OSCILLATIONS IN TEXTOR TOKAMAK PLASMAS
Authors: KUANG GUANG-LI  , G.WAIDMANN  ,   (1)Institut für Plasmaphysik/KFA Postfach 1913,D-5170  Jülich 1,Germany; (2)中国科学院等离子体物理研究所
Published: November 2020

The properties of the N41-1D oscillations (Mirnov Oscillations) in ohmic TEXTOR tokamak plasmas are systematically described in this paper based on experimental data, including mainly the principal modes of the MHD oscillations and the correlaion among the oscillations, the propagating direction of the MHD oscillations, as well as the correlative properties among the oscillative temperature, density and density fluctuation of the m=2/n=1 mode.
A STUDY FOR THE INFLUENCE OF RICINOLEIC ACID ON THE LIQUID CRYSTAL STRUCTURE IN THE MIXED PHOSPHOLIPID CHOLESTEROL LIPOSOMES BY MEANS OF SAXS AND 31P-NMR
Authors: SUN RUN-GUANG  , ZHANG JING  , DAI ZHENG-HUA  , XU FENG-XUN  , WANG DE-HUA  ,   陕西师范大学实验中心,西安710062;中国科学院理论物理研究所,北京100080
Published: November 2020

This report presents the results on the investigation of the effect of ricionoleic acid on the structures of the liquid crystal state of mixed phospholipid-cholesterol liposomes by means of the Small Angle X-ray Scattering (SAXS) and 31P Nuclear Magnetism Resomance(31P-NMR). The study shows that the ricinoleic acid helps to stabilize the structure of the mixed phospholipid-cholesterol liposomes and that the polyphase liposome with ricinoleic acid prepared from phosphoric buffer solution containing polyvinylpyrrolidone (PVP) is in the cubic-hexagonal phase.
MOTION ROUTE OF PARTICLES FROM PERIOD TO CHAOS IN LOCAL FIELD
Authors: OUYANG BI-YAO  , HE XIAN-TU  , CHEN SHI-GANG  ,   北京应用物理与计算数学研究所
Published: November 2020

We have studied the whole process from period to chaos in which the charged particle move in the periodic local solitary field, given out the character of orbit in phase space and the scale. We demonstrate that: in conservative system，the particle move from period to chaos by quasi-periodic way; but in dissipative system, it is achieyed by doubling periodic bifurcated way.
PHYSICAL CHARACTERISTICS OF WALL AND VOLUME EMISSIONS OF X-RAY IN LASER-CAVITY TARGET
Authors: SUN KE-XU  , YI RONG-QING  , CHENG JIN-XIU  , WANG HONG一BIN  , MA HONG-LIANG  , MU DAN-MIN  , LI YA-XUAN  , CUI YAN-LI  , TANG DAO-YUAN  , ZHENG ZHI-JIAN  ,   西南核物理与化学研究所
Published: November 2020

We present the studies of physical mechanisms of wall and volume emissions of X-ray for different type cavity targets on "Shen-guang" facility. The wavelength 1.053 μm, pulse shape-Gauss type, energy ～500-700J/beam, pulse width ～600-1000ps laser are used to irradiate cylindrical Hohlraum from two ends. The typical target consists of three cylindrical sections of which two ends are absorption-conver-sion regions of laser energy (source region), and the median is imploding region, which is heated by radiation energy from source region. The experiment results of X-ray wall and volume emission and some analyses are presented.
DEEP LEVEL STUDIES OF Ga1-xInxAs/InP LASERS GROWN BY LP-MOVPE
Authors: LU LI-WU  , ZHOU JIE  , FENG SONG-LIN  , DUAN SHU-KUN  ,   (1)北京半导体超晶格国家重点实验室,中国科学院半导体研究所; (2)北京集成光电子学联合实验室中国科学院半导体研究所实验区
Published: November 2020

The deep levels of Ga０．４７Ｉｎ０．５３As/InP lasers with broad, proton-bombarded stripe contacts and SQW (Single Quantum Well) grown by LP一MOVPE have been studied using DLTS (Deep Level Transient Spectroscopy) technique. DLTS Spectra of samples show that hole traps H1(Eｖ+0.09eV) and H2(Eｖ+O.11eV) and electron traps El (Eｖ-0.35eV) and E2 (Eｖ-0.42eV) present in Ga０．４７Ｉｎ０．５３As layer of lasers with broad and proton-bombarded stripe contacts, respectively. These traps may be related to Zn introduction in Ga０．４７Ｉｎ０．５３ As layer, native defect and interactions between H1 and damage induced by proton-bombardment, respectively. They may spatially localize in Ga０．４７Ｉｎ０．５３As layer and interface regions of discontinous variation In mole fraction of Ga1-xInx As layer with XIn=0.53.
A STUDY ON THE STATES OF ELECTRON IN A CLASS OF ONE-DIMENSIONAL POTENTIAL
Authors: TONG PEI-QING  ,   南京师范大学物理系
Published: November 2020

In this paper, we study the states of electron in one-dimensional potential Ｖn＝λｃｏｓ（Ｑn＋ａｎｖ）（０＜ｖ＜１），calculate the eigenvalues and localized exponents. For Ｑ＝２π／３, the energy band is constructed by three subbands. There are two mobility edges in every subband provided that λ<2. We study the nature of the localized and extended eigenstates and mobility edge of this system as a function of λ，ν and α.
STATISTICAL DYNAMICAL DIFFRACTION IN NEARLY PERFECT CRYSTALS
Authors: LI MING  , MAI ZHEN-HONG  , CUI SHU-PAN  ,   中国科学院物理研究所
Published: November 2020

A new expression of Takagi-Taupin equations is applied to nearly perfect crystals with statistical lattice distortion, with which a formalism of the dynamical diffraction is proposed. A static Debye-Waller factor E is introduced to characterize the crystal. A solution of the equations is presented which describe the intensity distribution due to a narrow incident wave in the topography of a statistically homogeneous crystal. The application of this theory to the measuring of the micro-defects in crvstals is discussed.
Eco-morphological diversity of larvae of soldier flies and their closest relatives in deep time
Authors: Baranov Viktor A. , Wang Yinan , Gašparič Rok , Wedmann Sonja , Haug Joachim T.
Published: November 2020

Stratiomyomorpha (soldier flies and allies) is an ingroup of Diptera, with a fossil record stretching back to the Early Cretaceous (the Barremian, about 125 MYA). Stratiomyomorpha includes at least 3,000 species in the modern fauna, with many species being crucial for ecosystem functions, especially as saprophages. Larvae of many stratiomyomorphans are especially important as scavengers and saproxyls in modern ecosystems. Yet, fossil larvae of the group are extremely scarce. Here we present 23 new records of fossil stratiomyomorphan larvae, representing six discrete morphotypes. Specimens originate from Cretaceous amber from Myanmar, Eocene Baltic amber, Miocene Dominican amber, and compression fossils from the Eocene of Messel (Germany) and the Miocene of Slovenia. We discuss the implications of these new records for our understanding of stratiomyomorphan ecomorphology in deep time as well as their palaeoecology.
A diverse global fungal library for drug discovery
Authors: Niu Guodong , Annamalai Thirunavukkarasu , Wang Xiaohong , Li Sheng , Munga Stephen , Niu Guomin , Tse-Dinh Yuk-Ching , Li Jun
Published: November 2020

Background

Secondary fungal metabolites are important sources for new drugs against infectious diseases and cancers.

Methods

To obtain a library with enough diversity, we collected about 2,395 soil samples and 2,324 plant samples from 36 regions in Africa, Asia, and North America. The collection areas covered various climate zones in the world. We examined the usability of the global fungal extract library (GFEL) against parasitic malaria transmission, Gram-positive and negative bacterial pathogens, and leukemia cells.

Results

Nearly ten thousand fungal strains were isolated. Sequences of nuclear ribosomal internal transcribed spacer (ITS) from 40 randomly selected strains showed that over 80% were unique. Screening GFEL, we found that the fungal extract from Penicillium thomii was able to block Plasmodium falciparum transmission to Anopheles gambiae, and the fungal extract from Tolypocladium album was able to kill myelogenous leukemia cell line K562. We also identified a set of candidate fungal extracts against bacterial pathogens.
Invasion history ofHarmonia axyridis(Pallas, 1773) (Coleoptera: Coccinellidae) in Ecuador
Authors: Cisneros-Heredia Diego F. , Peñaherrera-Romero Emilia
Published: November 2020

Harmonia axyridisis a ladybird extensively used around the world for biological control of agricultural pests. However, it has become invasive in several countries, producing negative ecological and socio-economic impacts. Herein, we review the invasion history of the Harlequin LadybirdHarmonia axyridis(Pallas, 1773) in Ecuador. Although first reported in Ecuador in 2012, museum specimens date back to 2004 and it is currently established across the country, especially along the Andean region. Due to its invasive nature, further studies are urgently needed to evaluate possible impacts ofH. axyridison the Ecuadorian biodiversity and agroindustry.
A Three in One Strategy to Achieve Zirconium Doping, Boron Doping, and Interfacial Coating for Stable LiNi0.8Co0.1Mn0.1O2 Cathode
Authors: Feng Ze , Rajagopalan Ranjusha , Zhang Shan , Sun Dan , Tang Yougen , Ren Yu , Wang Haiyan
Published: November 2020

LiNi0.8Co0.1Mn0.1O2 cathodes suffer from severe bulk structural and interfacial degradation during battery operation. To address these issues, a three in one strategy using ZrB2 as the dopant is proposed for constructing a stable Ni‐rich cathode. In this strategy, Zr and B are doped into the bulk of LiNi0.8Co0.1Mn0.1O2, respectively, which is beneficial to stabilize the crystal structure and mitigate the microcracks. Meanwhile, during the high‐temperature calcination, some of the remaining Zr at the surface combined with the surface lithium source to form lithium zirconium coatings, which physically protect the surface and suppress the interfacial phase transition upon cycling. Thus, the 0.2 mol% ZrB2‐LiNi0.8Co0.1Mn0.1O2 cathode delivers a discharge capacity of 183.1 mAh g−1 after 100 cycles at 50 °C (1C, 3.0–4.3 V), with an outstanding capacity retention of 88.1%. The cycling stability improvement is more obvious when the cut‐off voltage increased to 4.4 V. Density functional theory confirms that the superior structural stability and excellent thermal stability are attributed to the higher exchange energy of Li/Ni exchange and the higher formation energy of oxygen vacancies by ZrB2 doping. The present work offers a three in one strategy to simultaneously stabilize the crystal structure and surface for the Ni‐rich cathode via a facile preparation process.
Combinations of trabecular and cortical bone properties distinguish various loading modalities between athletes and controls
Authors: Saers Jaap P. P. , DeMars Lily J. , Stephens Nicholas B. , Jashashvili Tea , Carlson Kristian J. , Gordon Adam D. , Shaw Colin N. , Ryan Timothy M. , Stock Jay T.
Published: November 2020

Objectives

Variation in trabecular and cortical bone properties is often used to infer habitual behavior in the past. However, the structures of both types of bone are rarely considered together and may even contradict each other in functional interpretations. We examine trabecular and cortical bone properties in various athletes and sedentary controls to clarify the associations between combinations of cortical and trabecular bone properties and various loading modalities.

Materials and methods

We compare trabecular and cortical bone properties using peripheral quantitative computed tomography scans of the tibia between groups of 83 male athletes (running, hockey, swimming, cricket) and sedentary controls using Bayesian multilevel models. We quantify midshaft cortical bone rigidity and area (J, CA), midshaft shape index (Imax/Imin), and mean trabecular bone mineral density (BMD) in the distal tibia.

Results

All groups show unique combinations of biomechanical properties. Cortical bone rigidity is high in sports that involve impact loading (cricket, running, hockey) and low in nonimpact loaded swimmers and controls. Runners have more anteroposteriorly elliptical midshafts compared to other groups. Interestingly, all athletes have greater trabecular BMD compared to controls, but do not differ credibly among each other.

Discussion

Results suggest that cortical midshaft hypertrophy is associated with impact loading while trabecular BMD is positively associated with both impact and nonimpact loading. Midshaft shape is associated with directionality of loading. Individuals from the different categories overlap substantially, but group means differ credibly, suggesting that nuanced group‐level inferences of habitual behavior are possible when combinations of trabecular and cortical bone are analyzed.
The Generalized Uncertainty Principle
Authors: Li Jun‐Li , Qiao Cong‐Feng
Published: November 2020

The uncertainty principle lies at the heart of quantum physics, and is widely thought of as a fundamental limit of the measurement precision of incompatible observables. Here it is shown that the traditional uncertainty relation in fact belongs to the leading order approximation of a generalized uncertainty relation. That is, the leading order linear dependence of observables gives the Heisenberg type of uncertainty relations, while higher order nonlinear dependence may reveal more different and interesting correlation properties. Applications of the generalized uncertainty relation and the high order nonlinear dependence between observables in quantum information science are also discussed.
Development of antifouling ultrafiltration PES membranes for concentration of hemicellulose
Authors: Hliavitskaya Tatsiana , Plisko Tatiana , Pratsenko Svetlana , Bildyukevich Alexandr , Lipnizki Frank , Rodrigues Goncalo , Sjölin Mikael
Published: November 2020

A new approach for one‐stage facile membrane modification during non‐solvent induced phase separation (NIPS)‐process is proposed. The novelty of this study is that cheap and commercially available anionic high molecular polyacrylamide‐based flocculant (AHMPF) is applied for the first time as an additive to coagulation bath (CB). The series of polyethersulfone membranes were prepared using 0.05–0.3 wt% AHMPF aqueous solution as CB at different temperatures (25–50°C) via NIPS. The effect of AHMPF concentration on the structure, composition and hydrophilicity of membranes was investigated. The separation and antifouling performance were evaluated during filtration of bovine serum albumin (BSA) solution and thermomechanical pulp mills process water (ThMP) in order to concentrate hemicellulose. The successful immobilization of AHMPF into the structure of membranes selective layer (not bottom layer) was confirmed by FTIR spectroscopy. It was established that despite the similar rejection of hemicellulose (88.8–93%) and lignin (20–21.4), modified membranes demonstrate 3–8 times higher flux and 2 times higher FRR (43.8% for reference membrane and 86.5% for modified one) in ThMP ultrafiltration. The developed membrane was found to be highly efficient in hemicellulose concentration and purification in pulp industry.
Cyanine mitochondrial dye with slightly selective cytotoxicity against A549 cancerous cells
Authors: Skvortsov Dmitry A. , Emashova Sophia K. , Kalinina Marina A. , Dontsova Olga A.
Published: November 2020

Delocalized lipophilic cations (DLCs) are known as mitochondria‐addressed molecules. Mitochondria targeting may provide opportunities for tumor detection. DLCs may have antioxidant or anticancer properties. In this study, we focused on the toxicity and localization of 2‐[(E)‐2‐(5‐fluoro‐2‐methyl‐1H‐indol‐3‐yl)ethenyl]‐1,6‐dimethylpyridin‐1‐ium iodide (62E2), which has recently been found as a novel cytotoxic fluorescent compound. The excitation maximum of 62E2 is 452 ± 10 nm and its emission maximum is 579 ± 10 nm. It is accumulated in the cells and stains mitochondria in nanomolar concentrations. 62E2 is cytotoxic and mitotoxic in low micromolar concentrations, and it demonstrates some selectivity of cytotoxicity against A549 cancer cells. The closest analog of 62E2 is F16, which is the fluorescent mitotoxic agent that has been described earlier as a potential anticancer agent. We hope that 62E2 described here is useful in expanding the diversity of cyanine fluorescent mitochondrial dyes and the analysis of their structure–activity relationships.
Science for Competition among Powers: Geographical Knowledge, Colonial‐Diplomatic Networks, and the Scramble for Africa**
Authors: Gamito‐Marques Daniel
Published: November 2020

Historical studies on the relationship between science and diplomacy tend to focus on events since World War II and on initiatives for the maintenance of peace or to achieve cooperation over contentious matters. This article presents the case of José Vicente Barbosa du Bocage (1823–1907), a Portuguese zoologist who had formal diplomatic responsibilities in a context of competition for the colonization of Africa in the nineteenth century. He used his knowledge in African geography to implement colonial and diplomatic strategies that aimed at outcompeting rival powers. The development of a network of actors with scientific, colonial, and diplomatic expertise was crucial for the negotiations that involved the partition of the Congo basin, which resulted in victories for Portugal that surpassed the country's marginal political relevance at the international level and had long‐lasting consequences.
DNA adenine methylation in eukaryotes: Enzymatic mark or a form of DNA damage?
Authors: Bochtler Matthias , Fernandes Humberto
Published: November 2020

6‐methyladenine (6mA) is fairly abundant in nuclear DNA of basal fungi, ciliates and green algae. In these organisms, 6mA is maintained near transcription start sites in ApT context by a parental‐strand instruction dependent maintenance methyltransferase and is positively associated with transcription. In animals and plants, 6mA levels are high only in organellar DNA. The 6mA levels in nuclear DNA are very low. They are attributable to nucleotide salvage and the activity of otherwise mitochondrial METTL4, and may be considered as a price that cells pay for adenine methylation in RNA and/or organellar DNA. Cells minimize this price by sanitizing dNTP pools to limit 6mA incorporation, and by converting 6mA that has been incorporated into DNA back to adenine. Hence, 6mA in nuclear DNA should be described as an epigenetic mark only in basal fungi, ciliates and green algae, but not in animals and plants.
Food‐Grade Expression and Characterization of a Dextranase from Chaetomium gracile Suitable for Sugarcane Juice Clarification
Authors: Zhao Jingyi , Wang Leyi , Wei Xin , Li Kai , Liu Jidong
Published: November 2020

The microbial production of dextranase using cheap carbon sources is beneficial to solve the economic loss caused by the accumulation of dextran in syrup. A food‐grade microbial cell factory was constructed by introducing the dextranase encoding gene DEX from Chaetomium gracile to the chromosome of Bacillus subtilis, and the antibiotic resistance marker gene was subsequently deleted via the Cre/loxP strategy. The dual‐promoter system with a sequentially arranged constitutive P43 promoter resulted in an 85 % increase in DEX expression. Under the optimal fermentation conditions of 10 g/L maltose, 15 g/L casein, 1 g/L Na2HPO4, 1 g/L FeSO4 and 8 g/L NaCl, DEX activity was increased from 2.625 to 64.34 U/mL. Recombinant DEX was purified 5.98‐fold with a recovery ratio of 26.67 % and specific activity of 3935.02 U/mg. Enzyme activity was optimal at 55 °C and pH 5.0 and remained 80.34 % and 71.36 % of the initial activity at 55 °C and pH 4.0 after 60 min, respectively. The enzyme possessed high activity in the presence of Co2+, while Ag+ showed the strongest inhibition ability. The optimal substrate was 20 g/L dextran T‐2000. The findings could facilitate the low‐cost, large‐scale production of food‐grade DEX for use in the sugar industry.