bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF THE HIGH FREQUENCY ELECTRIC FIELD ON THE PLASMA DIAGNOSTICS BY THE DOUBLE PROBE
Authors: ZHU WEN-HAO  , WU YI-FENG  , CHEN YUE-SHAN  ,   清华大学工程力学系
Published: December 2020

In this paper, the expression for the double probe V-l characteristics and a formula to determine the electron temperature are derived. They are applicable whether the R. F. disturbance voltage drop across the probe sheath exists or not. The influence of this R. F. disturbance voltage on the double probe diagnostics for a low pressure plasma is investigated. Furthermore, the electron temperatures of the R. F. plasma under the pressure of 10-2—10-3 Torr are obtained experimentally. Experimental results agree with the theoretical analysis very well, k is also demonstrated that, if the electron energy distribution is Maxwillian, the R. F. disturbance has no substantial effect on the determination of electron temperatures of the plasma.
THE STUDIES OF THE INTERACTION BETWEEN THE PROMOTOR Co AND THE HIGHLY EDGED SURFACES OR ION SPUTTERED BASAL PLANE OF MoS2 CRYSTAL
Authors: HU YONG-JUN  , LIN ZHANG-DA  , WANG CHANG-HENG  , XIE KAN  ,   中国科学院物理研究所
Published: December 2020

To elucidate the promotion action of cobalt on Mo sulfide catalysts, UPS, XPS and LEED have been applied to study the submonolayer deposite process of promotor metal Co on the active catalytic phase for Co-Mo catalyst-the highly edged surfaces and ion sputtered basal plane of MoS2 crystal. At a certain submonolayer coverage of deposited Co, the new Co-correlated interface states could raise surface EF to a new higher pinning position by about 0.30-0.35eV. So the surface barrier and work function for these catalytic active phases are decreased. The remarkable changes for electronic structure near EF and the studies of LEED patterns reveal that the active phase Co-Mo-S, in which the Co-Mo bond appears to behave in much the same way as in the intermetallic bond, could be formed by locating the promotor Co at the surface disorder defects in edge sites.
THRESHOLD OF STOCHASTIC MOTION OF CHARGED PAR-TICLES IN GRADIENT MAGNETIC FIELD BY ELECTROSTATIC WAVE
Authors: MU JIAN-LIN  , CAI SHI-DONG  ,   (1)中国高等科学技术中心(世界实验室)理论物理分中心; (2)中国科学院物理研究所
Published: December 2020

Nonlinear effects of the gradient inhomogeneity of the magnetic field on the stochastic motion of charged particles due to an electrostatic wave propagated arbitarily relative to the magnetic field are considered in this paper. A sequence of canonical transformations is preformed to obtain a Hamiltonian explicitly exhibiting the possibility of the resonance between the periodic motion of particles and oscillation in the wave. The theoretical analysis shows that, due to the inhomogeneity of the magnetic field, the threshold for the onse of the stochasticity is changed and, in the case of weak inhomogeneity of the magnetic field, it is lowered, which means that the stochasticity appears more easily than in the case of uniform magnetic field.
TARGET ATOM EXCITATIONS IN COLLISIONS OF He+ AND He2+ WITH Na AT q×(20——140) keV
Authors: YU DE-HONG  , LIU JIA-RUI  , LEI ZI-MING  , YANG FENG  , PAN GUANG-YAN  , WANG DUAN-WEI  , SUN XIANG  ,   (1)中国科学院物理研究所; (2)中国科学院物理研究所,北京师范大学物理系; (3)中国科学院物理研究所,曲阜师范大学激光研究所
Published: December 2020

We have studied the target atom excitations in the collisions of He+ and He2+ with Na in the energy range ot q×(20-140) keV by optical measurements. The Nal 589.0 + 589.6 nm (3p→3s), Nal 818.3nm (3d→3p) and Nal 568.8 nm(4d→3p) lines for He+ + Na collision system have been observed by an OMA system. In He2+ + Na collision system, only Nal 589.0 + 589.6 nm line was observed. The emission cross sections of the Nal lines observed and Na (3p) excitation cross sections are calculated. An obvious effect of coulomb potential of projectile ions on the target excitation has been observed.
THE PRESSURE DEPENDENCE OF ENERGY GAP FOR MIXED CRYSTAL Hg0.3Cd0.7Te
Authors: JIANG SHAN  , ZHU HAO-RONG  , SHEN XUE-CHU  , J. SCHILZ  ,   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
Published: December 2020

The absorption edge of p-Hg1-xCdxTe with x = 0.7 has been measured at different pressures in the range of 0-36kbar and room temperature. The experimental energy gap is basically in agreement with the result calculated by empirical formula The first order pressure coefficient of Hg1-xCdx Te obtained by a least square fitting to experimental data under different pressures is a = 8.7×10-11eV/Pa, which can be explained by chemical bond dielectric function theory. The second order pressure coefficient of energy gap has also been obtained experimentally as β= -6.3×l0-13eV/ kbar which is hard to understand theoretically. In addition, a structural phase transition has been found under 34-36kbar.
CRYSTALLIZATION OF AMORPHOUS Nd3Fe81B16 ALLOYS AND ITS INFLUENCE ON MAGNETIC PROPERTIES AND M?SSBAUER SPECTRA
Authors: GU BEN-XI  , ZHAI HONG-RU  , SHEN BAO-GEN  , S. METHFESSEL  ,   (1)南京大学固体微结构实验室; (2)西德Bochum Ruhr大学第四实验物理研究所; (3)中国科学院物理研究所
Published: December 2020

Crystallization and its influence on magnetic properties and M?ssbauer spectra in the rapidly solidified amorphous Nd3Fe81B16 alloys are reported. The addition of 3at% Nd to FeB alloys raises the crystallization temperature from 435℃ for Fe81B19 to 523℃ for Nd3Fe81B16. After the crystallization at the optimal annealing condition the magnetic properties as permanent magnet were obtained to be: Br≈12kG, bHc = 2 kOe, and (BH)max≈8 MGOe, with room temperature seturation magnetization σs = 189 emu/g, remanence ratio σr/σs = 0.7 and intrinsic coercivity iHc = 2.15kOe. Comparing with widely used anisotropic BaFe12O19 ferrite, its Br and (BH)max is much higher. Therefore this material may be developed into a new cheap pe manent magnet. The influence of small addition of Nd on the physical properties of the alloys-are discussed. Based on the data from X-ray diffraction, M?ssbauer spectrocopy, SEM and magnetic measurments, the mechanism controlling the magnetization and demagnetization processes is thought to be domain wall pinning.
ANALYSIS OF WAVE FUNCTIONS FOR HYDROGEN ATOMS IN CLASSICAL LIMIT
Authors: HUANG XIANG-YOU  ,   北京大学物理系,北京,100871;中国高等科学技术中心(世界实验室)
Published: December 2020

Basing on the classical trajectory motion for an electron circling an atomic nucleus and averaging the motion over initial coordinate parameters of ellipse trajectories for the electron, we get a density distribution in space. This distribution is consistent with probability density of stationary state for hydrogen atom in the classical limit. This comparison shows that a wave function of hydrogen atom in stationary state does not describe an individual atom but an ensemble.
COERCIVE FORCE AND MAGNETOSTRICTION OF NONEQUILIBRIUM Fe-Pd ALLOYS
Authors: ZHANG SHENG-LIANG  , ZHAI HONG-RU  ,   南京大学物理系,南京,210008
Published: December 2020

The coercive force, Hc and magnetostriction, λs, have been measured for nonequilibrium Fe1-xPdx alloys, with increasing x, Hc decreases but λs, increases. The decrease of Hc may be related to the decrease in the average anisotropy due to the reduction of crystal grain size. After annealing above 600K, Hc increases rapidly because of the precipitation of the ordered FePd phase.
ABOVE-THRESHOLD-IONIZATION BY MULTIPHOTON ABSORPTION OF ATOM UNDER SHORT LASER PULSE
Authors: ZHANG WEN-QING  , TAN WEI-HAN  ,   中国科学院上海光学精密机械研究所,上海,201800
Published: December 2020

The Above-threshold-ionization(ATI) Spectrum of electrons produced by multiphoton absorption of atom has been obtained with spatial Gauss and temporal Sech shape of the incident laser pulse. It is found that our model can explain many phenomena such as peak suppression and switching. In addition, what is more important is that we can explain the red shift of the peaks decreases to zero gradually, as the pulse width changes from short to long pulse regime.
ALUMINIUM XUV SPECTRA EXCITED IN A LINE FOCUS LASER——PRODUCED PLASMA
Authors: HE AN  , HE SHAO-TANG  , CHUNYU SHU-TAI  , FANG QUAN-YU  , ZOU YU  , XU YUAN-GUANG  ,   (1)北京应用物理与计算数学研究所,北京,100088; (2)西南核物理与化学研究所,成都,610003
Published: December 2020

Aluminium targets were irradiated by line focus laser. We observed spectra of high ioni-zation states in the range of VUV. By means of Cowan program for atomic energy level, we caleulated the wavelength and gf value of different ionization state and identified 140 spectra lines.82 new spectra lines were found.
A NUMERICAL STUDY OF THE FOKKER-PLANCK EQUATION FOR STOCHASTIC RESONANCE PROBLEM
Authors: LU ZHI-HENG  , LIN JIAN-HENG  , HU GANG  ,   北京师范大学物理系,北京100875
Published: December 2020

The behavior of Fokker-Planck Equation for a stochastic resonance problem is studied by using finite difference schemes. The numerical results coincide with the analytical approximate theory under the conditions of adiabatic approximation ω?D?△V and small signal approximation A?1. Although the system rexhibits evidently deterministic non-linear vibration properties when the amplitude of periodic driving force is large, the adiabatic approximate analytical theory can cover the principal properties of stochastic resonance which occurs in the bistable system.
SINE-GORDON MODEL AND GAUSSIAN WAVE FUNCTIONAL
Authors: XU BO-WEI  , ZHANG YU-MEI  , LU WEN-FA  ,   (1)上海交通大学物理系,上海200030; (2)同济大学物理系,上海200092
Published: December 2020

With a general Gaussian wave functional, we study the ground states, one particle states, and two particle states of the sine-Gordon model. At the Coleman's critical point, the sine-Gordon system tends to a system of massless free bosons which possesses conformal symmetry. We also show that there exist bound states in two particle states as long as the renormalized mass remains finite.
SELF-INDUCED TRANSPARENCY IN THREE-LEVEL ATOM SYSTEM DRIVEN BY A COHERENT MICROWAVE FIELD
Authors: GUO GUANG-CAN  , GAO ZHUO-LIANG  ,   (1)安徽大学物理系,合肥230039; (2)中国科学技术大学物理系,合肥230026
Published: December 2020

The dynamic behaviour of interactions between three-level atoms system driven by a co-herence microware field and optical pulse is discussel. The optical area theorem has been de-rived and the self-induced transparency has been studied. It is found that some properties of this system is the same as two-level system under some special conditions.
WAITING TIME EFFECT IN POLYBUTADIEN
Authors: ZHU KE-JIA  , QIN XIAO-KUI  , CHEN HONG  , WU XIANG  ,   同济大学玻耳固体物理研究所,上海200092
Published: December 2020

The specific heat of polybutadien was measured and it was found that at temperature Tg = 178K there is a glass transition and the specific heat near the transition temperature depends strongly on the cooling process of the sample. After waiting at temperature Tw for a time tw during the cooling process, we found that there are waiting time effects on the specific heat of a heating process: the anomalous Δcp at Tp increases with the waiting time tw. In thecase of Tw=169K, Δcp(tw) can be described by Kohlrausch law Δcp(tw)～{l-exp[-(tw/τ)β]} with β =0.47±0.03.
A NEW REACTION MECHANISM——THE CONTACT REACTION OF LREM FILMS AND Si SUBSTRATE
Authors: HE JIE  , XU ZHEN-JIA  ,   (1)中国科学院半导体研究所,北京100083; (2)中国科学院表面物理国家重点实验室,北京100080
Published: December 2020

Light rare earth metal (LREM,La,Ce)films of 1500? thick were deposited on Si(lOO) substrate at room temperature under UHV condition. And a variety of techniques including AES,XRD and SIMS were used to study the thin film contact reaction between LREM and Si after isothermal annealing in the range of 200-400℃ for different durations. A new thin film contact reaction mechanism was observed. Taking into account the microscopic interfacial reaction, a model was suggested to elucidate this new reaction mechanism.
ELECTRONIC STRUCTURE OF STRAINED SUPERLATTICES (InAs)n(lnP)n(001):ab initio LMTO CALCULATION
Authors: KE SAN-HUANG  , WANG REN-ZHI  , HUANG MEI-CHUN  ,   中国高等科学技术中心(世界实验室),北京100080
Published: December 2020

The electronic structure of strained superlattices (SLS) (InAs)n(InP)n(001) are calculated with the Linearized-Muffin-Tin Orbitals (LMTO) band structure method in which the higher energy unoccupied d orbitals are treated by internal summation approach. The effects of In 4d orbitals on band structures are investigated. The valence band offsets (ΔEv) at SLS's are determined by a frozen-potential approach. The results show the bulk-like property is almost recovered in the molecular layers next to the interfaces. The band structure of (InAs)1(InP)1(001) given by the present work is well consistent with those given by more elaborate FLAPW calculation. The ΔEv values determined by the present calculation are in good agreement with those from XPS measurement and FLAPW method in which the core level or the macroscopic average potentials is used as a reference level. The small calculation effort and the satisfactory precision justify the present method as a very effective means for studying the electronic structures of multi-layers SLS.
PHOTOEMISSION STUDY OF VALENCE BAND DISCONTINUITY OF Si/GaP(Ⅲ)HETEROINTERFACE
Authors: HUANG CHUN-HUI  , CHEN PING  , WANG XUN  ,   (1)福州大学物理系,福州350002; (2)复旦大学表面物理国家重点实验室,上海200433
Published: December 2020

The growth procedure of the Si/GaP( Ⅲ )heterointerface with Si electron beam evaporation in an improved ADES-400 photo-electron spectrometer is introduced in this paper. Then the status of formation and valence band discontinuities of Si/GaP(Ⅲ ) heterointerfaces that grown under different conditions are analysed or measured in situ by photoemission. The relation of the ΔEv values with the status of the interface and the shift of atomic core levels is discussed. The growth condition of the abrupt and ordered Si/GaP(Ⅲ)heterointerfaces is determined. The value of valence band discontinuity in this case is 0.80eV. It agrees with theoretical results.
SPECTRAL PROPERTIES OF A SYSTEM IN TRANSITION TOCLASSICAL CHAOS——NUMERICAL RESULTS ON COUPLED SPIN MODEL
Authors: JIANG YI-MIN  ,   中国原子能科学研究院,北京102413
Published: December 2020

This article presents numerical results on the distribution ol nearest-neighbor level spac-ings Shd the avoided crossing behavior of quanitum energy curves for a cpupled spin model coming from nuclear many body theory. When the system undergoes a transition from classical regular to chaos and then to regular as varying a model parameter,the Brody parameter of the level spacing distribution p(s) could be fairly associated to the fraction of classical chaotic tra-jectories in phase space.;ln the regime of parameters with large chaotic regions, a number of overlapping avoided crossings were discovered from the results of computations, Which lead the energy curves looked irregular These results are considered as quantum manifestation or ‘scars' pf classidal chaos in spectrum.
A NEW METHOD TO STUDY THE HETEROGENEOUS ADSORPTION ON THE INTERFACES ON SURFACE ENHANCED RAMAN SCATTERING
Authors: LIU YE-HOU  , FU SHI-YOU  , ZHANG PENG-XIANG  , LI XIU-YING  , WANG YUN-SHAN  ,   (1)大庆石油学院基础课部,安达151400; (2)中国科学院物理研究所,北京100080
Published: December 2020

A new method to study chemical adsorption kinetics by means of surface enhanced raman scattering is proposed. The theoretical model is proposed and experimental results given out. The adsorption of CV and PABA molecules on the surfaces of silver mirrors and silver colloids is studied. It is found that the adsorption of CV on silver surfaces is homogeneous, and the adsorption of PABA is heterogeneous. The differences of silver surfaces only influence the adsorption rate constant Ka, not changing the heterogeneity character of adsorption and desorp-tion rate constant (Kd=0). Finally, the significance of heterogeneity paramter is discussed.
LASER COOLING OF AN ATOMIC BEAM WITH HIGH EFFICIENCY
Authors: LIU LIANG  , CHEN HONG-XIN  , WANG YU-ZHU  ,   中国科学院上海光学精密机械研究所;华东师范大学量子光学联合开放实验室,上海201800
Published: December 2020

In this paper, we calculate the radiation force on a two-level atom, whose levels are modulated by two far off resonance travelling wave fields, interacting with a near resonance travelling wave field. The results show that with appropriate conditions, the force can be much larger than spontaneous radiation force and then can be used in laser cooling with high efficiency.
SEGREGATION OF ARSENIC DURING THE SOLID STATE REACTION OF TERNARY Co/Ti/Si SYSTEM
Authors: LIU PING  , ZHOU ZU-YAO  , LIN CHENG-LU  , ZOU SHI-CHANG  , LI BING-ZONG  , SUN ZHEN  ,   (1)复旦大学电子工程系,上海200433; (2)中国科学院上海冶金研究所离子束开放研究实验室,上海200050
Published: December 2020

The bimetallic layers of Co/Ti were deposited by ion beam sputtering on silicon implanted with arsenic. The sample of Co/Ti/Si was treated by a multi-step annealing under nitrogen ambient. The behaviuor of arsenic during the reaction of ternary Co/Ti/Si system was studied by Rutherford backscattering sepctrometry (RBS). The results show that a multi-layer structure of TiN(O)/Co-Ti-Si/CoSi2/Si was formed by the reaction and a number of arsenic atoms were segregated from silicon substrate to the interlayer of Co-Ti-Si compound.
GROWTH OF INTERFACE WITH A LAW AND SPATIAL CORRELATIONS IN A CONSERVATIONAL SYSTEM
Authors: HAN FEI  , MA BEN-KUN  ,   北京师范大学物理系,北京100875
Published: December 2020

The growth behavious of interfaces in order parametes-conservation system with spatial correlation are analysed by using renormalization-group method. The scaling exponentχ and dynamic exponent z are obtained as functions of spatial dimension d and roughening exponent ρ. The result shows that the conservation condition makes the fluctuation Propagation decay, and spatial correlations make the interface roughen. The results are also compared with that of E. Medina et al. and T. Sun et al.
MAGNETIC VISCOSITY OF CHAIN-SPHERICAL Fe ULTRA-FINE PARTICLES
Authors: GAO XIAO-YUN  , LI JIN  , HOU DENG-LU  , YANG FU-MING  , ZHONG XIA-PING  , LUO HE-LIE  ,   (1)北京化工学院,北京100029; (2)中国科学院物理研究所,北京100080
Published: December 2020

This paper reports the study on the magnetic vicosity for chain-spherical Fe UFP prepared by laser pyrolysis. Fluctuation field,anisotropy and active volume of the particles were measured and calculated. The results show that the reverse magnetizing unit is made up of n chain spheres,and equivalent to a single-domain with uniaxial particle. Variation tendency of active volume of the particles is similiar to the acicular γ-type ferric oxide particles.
PHOTOREFLECTANCE SPECTRA FROM SURFACES AND GaAs-GaAs INTERFACES OF DOPED MBE GaAs FILMS
Authors: PAN SHI-HONG  , WANG ZHONG-HE  , HUANG SHUO  , ZHANG CUN-ZHOU  , ZHOU XIAO-CHUAN  , XU GUI-CHANG  , JIANG JIAN  , CHEN ZHONG-GUI  ,   (1)南开大学物理系,天津300071; (2)中国科学院半导体超晶格国家重点实验室,北京100083; (3)中国科学院表面物理国家重点实验室,北京100080
Published: December 2020

This paper reports the photoreflectance(PR) measurements of electric fields at the surface and the GaAs-GaAs interface of doped MBE GaAs films. By using alternatively He-Ne laser and He-Cd laser as pumping light, PR signals from the surface and the interface of the film can be effectively seperated the different penetration depth of different light. Electric fields at the surface and the interface were deduced from PR spectra. Film interference effects on modulation spectroscopy are studied. The origin of the electric field generated at interfaces are also discussed.
COLLISION CASCADES INDUCED BY LOW ENERGY CLUSTERS IMPACTING ON METALLIC THIN FILMS ( I )——HIGH ENERGY RECOIL ATOMS
Authors: PAN ZHENG-YING  ,   复旦大学物理二系,上海200433
Published: December 2020

Collision cascades of 1 keV/atom gold clusters and 0. 2 keV/atom aluminum clusters impacting on gold targets have been investigated by moleculardynamics simulation. The spectra of gold recoil atoms are broader for cluster bombardment. The maximum recoil energies are nearly 2? times higher than the kinematic limit of mono-atomic bombardment. The multiple hits and the collisions between moving atoms make the recoil energies of target atoms increase. The energy transfer between two moving atoms are studied by conservation laws.
THEORETICAL STUDY IN OSCILLATOR STRENGTH DENSITY——Oscillator Strength Density from 3s State to p-Channel States for Li-like Atomic Inos
Authors: LIU LEI  , LI JIA-MING  ,   (1)复旦大学物理系,上海200433;三束材料改性国家重点联合实验室,复旦大学分部,上海200433; (2)中国科学院物理研究所,北京100080
Published: December 2020

Based on the relativistic and non-relativistic self-consistent-field methods, we have calculated the oscillator strength density from 3s state to p-channel states for Li-like atomic ions. The dependence of the oscillator strength density on atomic number and some related relativistic effects are discussed. Using the calculated oscillator strength density as interpolation benchmark points, one can easily obtain oscillator strengthes of all 3s-np transitions for Li-like atomic ions (3≤z≤92).
A STUDY OF C60+ COLLISIONAL FRAGMENTATION
Authors: GAO HAI-BIN  , FANG DU-FEI  , LU FU-QUAN  ,   复旦大学物理二系,上海200433
Published: December 2020

The C60+ fragmentation caused by electron collision has been studied with a 911A ion source of a mini-separator at the Accelerator Laboratory of Fudan University. The mass spectrum of the fragments has been measured. We found that the fragments contain even number of carbon atoms and the strength of the beam current shows an exponential distribution. Our results show that the fragmentation caused by electron collision has some similarities to that of atomic collision at the energy about 300 keV.
REFLECTION PROPERTIES OF OBLIGUE-INCIDENT WAVES IN CONTINUOUSLY-CHANGABLE-DIMENSION FRACTAL CANTOR LAYERS
Authors: CHEN LU-JUN  , LIANG CHANG-HONG  , WU HONG-SHI  ,   西安电子科技大学,601室西安710071
Published: December 2020

Reflection and transmission spectra of obligue-incident waves at a kind of general contin-uously-Changeable-dimension fractal cantor Layers are investigated. With the self-similarity, a generalized method and formulae as well as a new type of reflection and transmission spectra, i. e. the self-similar spectra, are abbained. This is a new physical phenomena which would find some application.
ELECTRON HOLOGRAPHY AND ITS APPLICATION ON OBSERVATION OF MICRO-ELECTROSTATIC FIELD DISTRIBUTION
Authors: CHEN JIAN-WEN  , WANG ZHI-JIANG  ,   中国科学院上海光学精密机械研究所,上海201800
Published: December 2020

Principle of electron holography and a new method for producing the electrostatio field specimen are presented. Some dielectric particles supported by a thin carbon film, for example, polystarene latex spheres, 0.31 m in diameter, will become a charged body during the observation in electron microscope because of electrostatic accumulation. Obviously, under the electron beam, the spheres of radius r, acquire a stationary positive charge Q and the resulting field can be simply modelled by that of point charge Q. With the field model, the electrostatic field distribution were observed and the sizes of the charged objects are determined by electron holography.
MODE ITINERANCY IN A PHOTOREFRACTIVE RING OSCILLATOR
Authors: ZHUANG JUN  , TAN WEI-HAN  ,   (1)上海大学物理系; (2)中国科学院上海光学精密机械研究所高功率激光物理国家实验室
Published: December 2020

A theory of multimode oscillation in an optical unidirectional ring resonator with photorefractive gain was given in the weak-field limit. In nondegenerate state, the system is stable and can be described by Lotka-Voterra equation. While the system will becomes unstable in certain circumstance owing to the mode-mode interaction in the degenerate or quasi-degenerate condition, such as the periodic alternation behavior.
SHORT WAVELENGTH SPIN WAVE MODE EXCITATION BOUND TO THE DOMAIN WALLS IN MAGNETIC THIN FILM
Authors: CHEN SHAN-BAO  , ZHANG ZHI-QIANG  ,   华中理工大学固体电子学系
Published: December 2020

A structure for short wavelength spin wave mode excitation is developed, which is used to investigate a spin wave (Winter mode) bound to the domain wall in a magnetic bubble film with an rf magnetic field produced by a microstrip carrying rf current, a thin permalloy grating on the top of the magnetic specimen generates secondary magnetic fields which match the time frequency and spatial wavelength of the spin wave, and an efficient coupling between them is realized By means of phase lock-in techniques a differential absorption peak corresponding to the Winter mode has been observed at 318 MHz.
LASER LINEWIDTH WITHOUT ROTATING WAVE APPROXIMATION
Authors: XIONG JIN  , HU XIANG-MING  , PENG JIN-SHENG  ,   化中师范大学物理系，武汉  430079
Published: December 2020

In this paper the laser linewidth without rotating wave approximation is studied by keeping the ratio of the atomic natural decay rate to the radiation frequency to two orders.It is shown that while the linewidth is confined to the Schawlow-Townes formula,the non-rotating wave terms would cause the linewidth to increase since the non-rotating wave terms decrease the average photon number.The degree of increasing in linewidth depends not only on the square of the ratio of the atomic natural de-cay rate to radiation frequency,but also on the average photon number in rotating wave approxima-tion.The influence of the non-rotating wave terms on the laser linewidth is much larger than on the photon number fluctuations.
EXPERIMENTAL STUDY ON A RF-EXCTTED SLAB WAVEGUIDE CO2 LASER WITH THE FAR FIELD INTENSITY DISTRIBUTION OF A SINGLE SUPPRESSED PEAK
Authors: JIAO WEN-TAO  , XIN JIANGUO  ,   北京理工大学光电工程系，北京  100081
Published: December 2020

In this paper,we have studied experimentally the properties of the mode structure and modes evolution of a slab waveguide CO2 laser with a far field intensity distribution of a single spatially sup-pressed peak. It has been found that the laser mode is a new single mode of a slab waveguide CO2 laser,which has a different mode structure from the known mode of slab waveguide gas laser.
STUDY OF MAGNETICALLY INDUCED TWIST EFFECT IN PLANAR NEMATIC LIQUID CRYSTAL BY PHASE RETARDATION METHOD
Authors: LIN ZI-YANG  , XIANG YING  , ZHANG JIE-LI  , MA SHI-YONG  , XU ZE-DA  ,   (1)暨南大学物理系，广州  510632；中山大学物理系，广州  510276; (2)深圳风达液晶厂，深圳  518000; (3)中山大学物理系，广州  510276
Published: December 2020

In this paper,numerical calculations of magnetically induced twist effeet in planar nematic liquid crystal are presented.The transmission of polarized light passing through magnetically induced twist distribution in planar nematic liquid crystal is calculated with “4*4”matrix algorithm.On the ex-perimental side,the optical phase retardation method is used to detect the magnetically induced twist effect in planar nematic liquid crystal 5CB(4′-n-penty1-4-cyanobiphenyl) at 27℃.Theoretical cal-culation and experimental results illustrate that polarized light can be used to study the twist effect in thin sample of planar nematic liquid crystal.
POSSIBILITY OF FACETING TRANSFORMATION OF Mo AND W FROM (111) TO {110} INDUCED BY ULTRATHIN FILM Rh
Authors: HUANG DAN-YUN  , CHE JING-GUANG  , ZHANG KAI-MING  ,   复旦大学应用表面物理国家重点实验室，上海  200433
Published: December 2020

Using first principles total energy calculations,the surface energies of Mo and W before and af-ter adsorbing Rh thin films in [111] and [110] orientations are calculated.The calculation results indicate that clean (111) surfaces of both Mo and W cannot transform to {110} facets,in agreement with experimental observations.When the coverage of Rh arrives at one physical monolayer,Rh/Mo(111) still cannot facet to {110},while under a favorable energy condition for the transforma-tion,Rh/W(111) may facet to {110}.
EPITAXIAL GROWTH OF PEROVSKITE OXIDE THIN FILMS
Authors: LIAN GUI-JUN  , LI MEI-YA  , KANG JIN-FENG  , GUO JIAN-DONG  , SUN YUN-FENG  , XIONG GUANG-CHENG  ,   (1)北京大学物理系与介观物理国家重点实验室，北京  100871; (2)北京大学物理系与介观物理国家重点实验室，北京  100871；汕头大学物理系，汕头  515063
Published: December 2020

Based on the ahievement of epitaxial growth in several Perovskite oxide films,we discuss the importance of substrate temperature (Ts) and substrate material in the epitaxial growth of per-ovskite oxide thin films.Influences of Ts on growth orientation and epitaxial threshold temperature were observed.The results indicate that during the growth of the oxide films the phase formation and growth dynamics should be taken into considera tion.The threshold temperature for epitaxial growth depends on the substrate materials.This demonstrates the influence of substrate material on the initial nucleation and epitaxial growth.
EXACT SOLITON SOLUTIONS OF THE VARIABLE COEFFICIENT KdV-MKdV EQUATION WITH THREE ARBITRARY FUNTIONS
Authors: YAN ZHEN-YA  , ZHANG HONG-QING  ,   大连理工大学数学科学研究所，大连  116024
Published: December 2020

In this paper,first,by using a new transformation,the variable coefficient KdV-MKdV equation is reduced to a third-order nonlinear ordinary differential equation (NODE),and then several exact soliton-solutions for the variable coefficient KdV-MKdV equatioin are obtained through considering this NODE.The method can be also used to solve other nonlinear equations,such as the variable coefficient KP equation,sine-Gordon equation and so on.
EXACTLY SOLVABLE POTENTIAL WITH FOUR PARAMETERS FOR DIATOMIC MOLECULES
Authors: SUN JIU-XUN  ,   电子科技大学应用物理系，成都  610054
Published: December 2020

A four-parameter potential function is proposed.The corresponding s-wave Schrdinger equation is solved exactly,and the rotational energy is approximately considered by using a simple method.The evaluating accuracy of the potential for the experimental RKR curve and the rotational-vibrating level is far better than the usual Morse potential,and the latter is contained in this potential as a special case.
DYNAMICAL INVESTIGATION ON MOMENTUM SPREAD OF TWO-LEVEL ATOMS BY A MODULATED STANDING LIGHT WAVE
Authors: WANG ZHONG-JIE  , LU YI-QUN  , LU TONG-XING  ,   (1)安徽师范大学物理系，芜湖  241000; (2)中国科学院安徽光学精密机械研究所，合肥  230031
Published: December 2020

In this paper the model of two-level atomic momentum spread in amplitude-modulated standing light wave was investigated.This model shows chaotic behaviour in the classical limit.The system displays the characteristic of dynamical localization for the same parameters as those in the classical model correspoinding to it.
THE STABILITY OF A KIND OF COSMOLOGICAL MODEL
Authors: WANG YONG-JIU  , TANG ZHI-MING  ,   湖南师范大学物理研究所,长沙410081
Published: December 2020

The stability of a kind of cosmological models is given. The variations of the cosmological model for parameters λ and k were discussed respectively. Near λ=0, the cosmological model is unstable with the change of λ, and near λ=β=0, the cosmological model is unstable with the change of k. So when we consider the stable cosmological model, we must consider the no-zero cosmological constant.
EXPLICIT EXACT SOLUTIONS OF GENERALIZED B-BBM AND B-BBM EQUATIONS
Authors: CHEN SONG-LIN  , HOU WEI-GEN  ,   安徽工业大学数理系,马鞍山市243002
Published: December 2020

The deformation theory for the solutions of BBM equation and generalized B-BBM equation and homogenous balance methods(HBM) for B-BBM equation are studied. The authors propose a new class of deformation formula which can produce the exact explicit solutions of generalized B-BBM equation by deforming the known solution of BBM equation. This paper concludes with an elementary example. As a byproduct, another class of deformation relation(called hybrid) is obtained.
PHYSICAL PROPERTIES OF WEDGE-SHAPED Al THIN FILM
Authors: TAO XIANG-MING  , LAO YAN-FENG  , YE QUAN-LIN  , JIN JIN-SHENG  , JIAO ZHENG-KUAN  , YE GAO-XIANG  ,   浙江大学物理系,杭州310028
Published: December 2020

A wedge-shaped aluminum thin film system, deposited on glass surfaces by a vapor deposition method, has been fabricated. By using the expansive and movable behaviours of silicone oil drops, the Al films are quenched gradually by the silicone oil during the deposition process. An anomalous wedge-shaped structure with a slope of 10-6—10-7 spontaneously forms. The I-V characteristic of the system has been studied and its rough effect cannot be interpreted as RRN model of the normal rough thin films.
EXPERIMENTAL STUDY OF LOCAL FLUX CREEP ON A CYLINDRICAL MELTING-TEXTURED GROWN YBa2Cu3O7-δ SAMPLE AT APPLIED FIELDS
Authors: LIU FENG  , HUANG JUN-WEI  , LIU WEI  , XIAO LING  , REN HONG-TAO  , JIAO YU-LEI  , ZHENG MING-HUI  , YAN SHOU-SHENG  ,   (1)北京大学物理系和介观物理国家重点实验室,北京100871; (2)北京有色金属研究总院,北京100088
Published: December 2020

Using semiconductor Hall probes,we studied the local flux creep on a cylindrical melting-textured grown YBa2Cu3O7-δ sample at liquid nitrogen temperature and low applied field.The measurements on the top surface of the sample show that the local flux creep fits well the logarithmic time dependence in both the field-on and field-off cases.The obtained activation energy U0 in the field-on case is greater than the field-off one.The local magnetization was almost changing with the applied field synchronously in the measurement of magnetic hysteresis loops.The field was almost identical at a fixed local point under various sweep ratios of the applied field.The results imply that besides the side surface the applied field penetrates into the upper and lower surfaces to a certain extent too.The disparity in U0 results from the difference of the angle between the flux line and the ab plane.This study also shows that the measurement of flux creep at the low field has a potential to become a simple and effective method to investigate the pinning property in large size samples.
Theoretical and numerical study on breakdown mechanism of nitrogen spark switch
Authors: Sun Qiang , Zhou Qian-Hong , Song Meng-Meng , Yang Wei , Dong Ye ,   Institute of Applied Physics and Computational Mathematics, Beijing 100094, China,   Graduate School of China Academy of Engineering Physics, Beijing 100088, China
Published: December 2020

Compared with the two-electrode gas spark switch, the three-electrode gas spark switch has high controllability, low working voltage and small jitter, so the three-electrode gas spark switch is widely used in pulse power technology. The discharge of gas spark switch is high pressure gas discharge, which is characterized by high electron collision frequency (1012 Hz), small mean free path (10–6 m), short breakdown time (10–9 s), and complex physical process (including the secondary electron emission, the generation of seed electrons, the space charge effect and various collision processes between electrons and nitrogen molecules, etc). At present, it is difficult to quantitatively describe the breakdown process of the three-electrode gas switch, and the detailed theoretical research is lacking. Therefore, the breakdown mechanism of atmospheric pressure nitrogen spark switch, including two-electrode and three-electrode, is studied theoretically and numerically in this paper. The purpose of this study is to compare the simulation results of the two different gas spark switches, and obtain the characteristics of stream breakdown in different gas spark switches. Firstly, the numerical simulation and theoretical analysis of two-electrode gas spark switch are carried out. According to theoretical and numerical calculation, it can be found that for the plate-plate two-electrode switch, the stream breakdown cannot be generated under low voltage (less than 6.3 kV), while under high voltage (more than 6.3 kV), first the anode-directed streamer is formed, and then the cathode-directed streamer is created. In addition, the simulation results show that the plasma generated by the trigger can effectively reduce the breakdown voltage. Finally, the three-electrode gas spark switch is studied theoretically and numerically. It can be seen that in the breakdown process of the three-electrode gas spark switch, the breakdown first occurs between the trigger and the insulator, and then this plasma channel expands to the anode and cathode, finally forming the arc channel between the anode and the cathode. Under the calculation conditions in this paper, if the cathode-trigger and the anode-trigger are required to break down simultaneously, the applied voltage between the cathode-trigger should be greater than 1.18 kV, while the applied voltage between the anode-trigger should be greater than 3 KV. When the field emission of the trigger is considered, the breakdown threshold can be significantly reduced.
Application of particle swarm optimization in optimal placement of tsunami sensors
Authors: Ferrolino Angelie , Mendoza Renier , Magdalena Ikha , Lope Jose Ernie
Published: December 2020

Rapid detection and early warning systems demonstrate crucial significance in tsunami risk reduction measures. So far, several tsunami observation networks have been deployed in tsunamigenic regions to issue effective local response. However, guidance on where to station these sensors are limited. In this article, we address the problem of determining the placement of tsunami sensors with the least possible tsunami detection time. We use the solutions of the 2D nonlinear shallow water equations to compute the wave travel time. The optimization problem is solved by implementing the particle swarm optimization algorithm. We apply our model to a simple test problem with varying depths. We also use our proposed method to determine the placement of sensors for early tsunami detection in Cotabato Trench, Philippines.
Use of next generation sequencing to compare simple habitat and species level differences in the gut microbiota of an invasive and native freshwater fish species
Authors: Gallo Benjamin D. , Farrell John M. , Leydet Brian
Published: December 2020

Research on the gut microbiome of host organisms has rapidly advanced with next generation sequencing (NGS) and high-performance computing capabilities. Nonetheless, gut microbiome research has focused on mammalian organisms in laboratory settings, and investigations pertaining to wild fish gut microbiota remain in their infancy. We applied a procedure (available at https://github.com/bngallo1994) for sampling of the fish gut for use in NGS to describe microbial community structure. Our approach allowed for high bacterial OTU diversity coverage (>99.7%, Good’s Coverage) that led to detection of differences in gut microbiota of an invasive (Round Goby) and native (Yellow Bullhead) fish species and collected from the upper St. Lawrence River, an environment where the gut microbiota of fish had not previously been tested. Additionally, results revealed habitat level differences in gut microbiota using two distance metrics (Unifrac, Bray–Curtis) between nearshore littoral and offshore profundal collections of Round Goby. Species and habitat level differences in intestinal microbiota may be of importance in understanding individual and species variation and its importance in regulating fish health and physiology.
Peripheral-physiological and neural correlates of the flow experience while playing video games: a comprehensive review
Authors: Khoshnoud Shiva , Alvarez Igarzábal Federico , Wittmann Marc
Published: December 2020

The flow state is defined by intense involvement in an activity with high degrees of concentration and focused attention accompanied by a sense of pleasure. Video games are effective tools for inducing flow, and keeping players in this state is considered to be one of the central goals of game design. Many studies have focused on the underlying physiological and neural mechanisms of flow. Results are inconsistent when describing a unified mechanism underlying this mental state. This paper provides a comprehensive review of the physiological and neural correlates of flow and explains the relationship between the reported physiological and neural markers of the flow experience. Despite the heterogeneous results, it seems possible to establish associations between reported markers and the cognitive and experiential aspects of flow, particularly regarding arousal, attention control, reward processing, automaticity, and self-referential processing.
The p53 signaling pathway of the large yellow croaker (Larimichthys crocea) responds to acute cold stress: evidence via spatiotemporal expression analysis of p53, p21, MDM2, IGF-1, Gadd45, Fas, and Akt
Authors: Qian Baoying , Qi Xin , Bai Yi , Wu Yubo
Published: December 2020

The p53 activation is induced by stressors, such as DNA damage, oxidative stress, and activated oncogenes, and can promote cell cycle arrest, cellular senescence, and apoptosis. The large yellow croaker (Larimichthys crocea) is an important warm temperate marine fish in the Chinese aquiculture industry. However, few studies have investigated the role of p53 in the response of L. crocea to environmental stressors. Therefore, the aim of the present study was to assess the spatiotemporal mRNA expression levels of genes involved in the p53 signaling pathway of the large yellow croaker in response to cold stress. The results showed significant changes in the expression levels of p53, p21, MDM2, IGF-1, Gadd45, Fas, and Akt in various tissues of the large yellow croaker in response to cold stress for different times. As compared to the control group, p53 mRNA expression was upregulated in most of the examined tissues at 24 h with the exception of the gill. In the liver, the expression levels of p53 and Fas were significantly decreased at 12 h, while those of p21, MDM2, IGF-1, Gadd45 were dramatically increased. Akt expression was notably changed in response to cold in several tissues. These results suggested that p53 was potentially a key gene in the large yellow croaker response to cold and possibly other environmental stressors.
Utilizing sponge spicules in taxonomic, ecological and environmental reconstructions: a review
Authors: Łukowiak Magdalena
Published: December 2020

Most sponges produce skeletons formed by spicules, structural elements that develop in a wide variety of sizes and tridimensional shapes. The morphologies of spicules are often unique to clade- or even species-level taxa which makes them particularly useful in taxonomic assignments. When dead sponge bodies disintegrate, spicules become incorporated into sediments and sometimes accumulate into enormous agglomerations called spicule mats or beds, or fossilize to form special type of rocks called the spiculites. The record of fossil and subfossil sponge spicules is extraordinarily rich and often serves as a basis for far-reaching reconstructions of sponge communities, though spicules are also bearers of significant ecological and environmental information. Specific requirements and preferences of sponges can be used to interpret the environment in which they lived, and reconstruct oscillations in water depths, pH, temperatures, and other parameters, providing snapshots of past climate conditions. In turn, the silicon isotope compositions in spicules (δ30Si) are being increasingly often used to estimate the level of silicic acid in the marine settings throughout the geological history, which enables to reconstruct the past silica cycle and ocean circulation. This contribution provides a review of the use of sponge spicules in reconstructions of sponge communities, their ecology, and environments, and aims to detect the pertinent gaps in their utilization. Even though spicules are well known for their significance as bearers of taxonomic, ecological, and environmental data, their potential remains to be fully exploited.
Psychosocial variables and quality of life during the COVID-19 lockdown: a correlational study on a convenience sample of young Italians
Authors: Lardone Anna , Sorrentino Pierpaolo , Giancamilli Francesco , Palombi Tommaso , Simper Trevor , Mandolesi Laura , Lucidi Fabio , Chirico Andrea , Galli Federica
Published: December 2020

Background

In 2020, to limit the spread of Coronavirus (COVID-19), many countries, including Italy, have issued a lengthy quarantine period for the entire population. For this reason lifestyle has changed, bringing inevitable repercussions to the Quality of Life (QoL). The present study aims to identify which psychosocial variables predict behaviors capable of affecting the QoL during the lockdown period, potentially highlighting factors that might promote well-being and health in the Italian population during the epidemic.

Methods

Between 27 April 2020 and 11 May 2020, we administered a web-survey to a sample of young Italian people (age M = 21.2; SD = 3.5; female = 57.7% of the sample). Employing variance-based structural equation modeling, we attempted to identify whether social connectedness, social support, and loneliness were variables predictive of the QoL of young Italians. We also sought to identify specific psychological factors, such as symbolic threat, realistic threat, and the threat from potentially contaminated objects, was correlated to COVID-19 fear and whether engaging in particular behaviors was likely to improve the QoL.

Results

Our results suggest that social connectedness and loneliness are significant predictors of QoL, while social support did not have a significant effect on QoL. Furthermore, we observed that symbolic and realistic threats and the threat from potentially contaminated objects are significant and positive predictors of COVID-19 fear. Moreover, COVID-19 fear had significant and positive relationships with the carrying out of specific behaviors, such as creative activities during the isolation period and that this related to affirming individuals’ country-specific identity. Finally, COVID-19 fear is a significant predictor of behavioral factors related to the adherence to public health advice in line with national guidance regarding the containment of COVID-19; this factor, however, did not correlate with QoL.

Conclusion

Our results suggest the importance of social context and psychological factors to help devise intervention strategies to improve the QoL during lockdown from epidemic events and, in particular, support the importance of promoting social communication and accurate information about the transmission of the virus.
Proximate, Anti-Nutrients and Elemental Constituents of C. esculenta
Authors: Chinenye Oguazu E. , Chidiebere Achilike I. , Nnenna Ani O.
Published: December 2020

Cocoyam (C. esculenta) is an aroid that is grown most importantly for edible corms. C. esculenta is used by the locals, it has been noted that when used as feed, it causes swelling of the lips, mouth and throat. The aim of this work was to investigate the proximate, anti-nutrients and elemental constituents of C. esculenta. Proximate, elemental and anti-nutrient constituents of C. esculenta were investigated. For the mineral composition Atomic absorption spectrometer was used, while a standard method of analysis by American Organization of Analytical Chemistry was adopted for the proximate analysis and anti-nutrient composition. After the experiment, the data obtained were presented as mean± SD and were subjected to statistical analysis using student T-test, to determine the level of significance at p≤0.05. The results showed that for the two samples, the flour processed with the bark has highest concentrations of carbohydrate and minerals, but the bark has a higher concentration of anti-nutrients which causes swollen lips, scratchiness of throat and astringent taste.
Shelf Life of Nori from Eucheuma cottonii with Aluminum Foil Packaging Based on the Accelerated Shelf Life Test Method
Authors: Marsvia Sucita Amanda , Liviawaty Evi , Rochima Emma , Afrianto Eddy
Published: December 2020

This research aims to determine the shelf life of Nori from Eucheuma cottonii in aluminum foil packaging using the Accelerated Shelf Life Test (ASLT) method with the Arrhenius approach model. This research was conducted using aluminum foil packaging to package Eucheuma cottonii nori products in 2 different storage temperatures, namely 25°C and 35°C. Observations were made on the 35th day with a countdown method which included sensory testing and moisture content testing. The data from the observations had analyzed the estimation of shelf life using the Arrhenius approach model. The results showed that the taste quality parameter is a critical parameter that determines the shelf life of Eucheuma cottonii nori using aluminum foil packaging. The shelf life of nori from Eucheuma cottonii using aluminum foil packaging has a shelf life of 2 months 14 days 17 hours.
Hawking Radiations of Kerr-Newman Black Hole in de Sitter Spacetime by Hamilton-Jacobi Method
Authors: Hossain M. Ilias , Hossain M. Jakir
Published: December 2020

Incorporating Parikh and Wilczek’s opinion Hawking radiations of Kerr-Newman-de Sitter (KNdS) black hole has been investigated by Hamilton-Jacobi method. We have assumed the space time background as dynamical, energy and angular momentum as conserved incorporating the self-gravitation effect of the emitted particles. We have shown that the massive particle tunneling rate is related to the change of Bekenstein-Hawking entropy and the derived emission spectrum deviates from the pure thermal spectrum.