bluuebunny/crossref_metadata_2025 huggingface dataset:
INVESTIGATION OF THE STRUCTURES OF ZnTe/GaSb BY X-RAY TRIPLE-AXIS SCATTERING AND CRYSTAL TRUNCATION ROD
Authors: LI CHAO-RONG  ,   中国科学院物理研究所中国科学院凝聚态物理中心
Published: December 2020

The structures of ZnTe/GaSb, grown by molecular beam epitaxy under different conditions, were investigated by X-ray triple-axis scattering and crystal truncation rod. The sample annealed under Zn flux from surface cleaning temperature to growth temperature had clear interference fringes in the crystal truncation rod scan profile, while the sample annealed under Te flux shows no interference fringes in the crystal truncation rod. Reciprocal space mapping around the symmetrical diffraction reciprocal point 004 and asymmetrical diffraction point 115 showed that the ZnTe epilayers were fully strained to the substrate. Both two-dimensional reciprocal space mapping and transverse scan along direction showed that the sample annealed under Te flux had strong and broad diffuse scattering in this direction. This was attributed to the Ga2Ｔｅ3 formation at the interface. This interfacial phase would enhance the diffuse scattering, blur the interference fringes and roughen the surface and interface. The epilayer thickness was accurately determined to be (210±1)nm by theoretical calculation of the experimental profiles. The surface roughness of the sample annealed under Zn flux, (2.2±0.2)nm, was smaller that of the sample annealed under Te flux, (3.7±0.3)nm.The lateral correlation lengths of the samples annealed under Zn flux and Te flux are (420±10)nm and (30±5)nm,respectively.
PHASE TRANSITION AND NESTING IN LOW DIMENSION
Authors: LING FAN  , CHEN XIAO-BING  , FU RONG-TANG  , SUN XIN  , Y. KAWAZOE  ,   (1)复旦大学物理系;中国科学院红外物理国家重点实验室; (2)日本东北大学材料研究所; (3)扬州大学师范学院物理系
Published: December 2020

The nesting of the Fermi surface in a two-dimensional (2D) system is not perfect, which is distinctly different from one-dimensional system. The nesting deviation can heavily suppress the instability of 2D system. In this paper, the effect of the nesting deviation on the Peierls transition is quantitatively studied, and the limit for the nesting deviation, beyond which the Peierls transition is destroyed, is determined. Such a behavior is favorable to get the superconductivity.
KINETICS AND SCALING BEHAVIOR OF REACTION PERCOLATION BALLISTIC SURFACE GROWTH
Authors: ZHU XIAO-BIN  , WANG WEI  ,   南京大学物理系固体物理研究所
Published: December 2020

The kinetics and scaling behaviors of reaction-percolation ballistic surface growth with two kinds of particles A and C is investigated. When the probability of particle C is zero, i.e. q=0,the deposition is the traditional ballistic deposition of single particle. When the probability is not zero,i.e.q≠0, in 2+1 dimensions and 3+1 dimensions, the morphological structural transitions are observed. When q approaches the threshold, at which the growth will stop, there is a scaling behavior for the growth velocity, which can be interpreted by the percolation theory.
PRELIMINARY STUDY ON THE NEAR FIELD OPTICS
Authors: WANG GUI-YING  ,   中国科学院上海光学精密机械研究所
Published: December 2020

An analytic expression have been obtained by using asymptotic approximations to the type of integral expression that frequently occurs in near field optics.By using the expression,the image degradation and some factors repressurized by imaging system of the near field optics are interpreted respectively.Furthermore,an expression of the degrees of freedom of scanning near field optical microscopy is given.Also the relation between the resolution and the degrees of freedom in the scanning image system of near field optics is analyzed.
MULTILAYER RELAXATION OF Al SURFACE APPLICATION OF THE MODIFIED EMBEDDED ATOM POTENTIALS
Authors: SHEN SAN-GUO  , WAN JUN  , FAN XI-QING  ,   郑州大学物理工程学院
Published: December 2020

The multilayer relaxation of Al(100),(110),(111) and (210),(211),(310),(311) and (331) surfaces is calculated using the modified embedded atom method. The results are in good agreement with the experimental data and first-principle calculations. Especially, the results for Al(100) and (111), which show “anomalous” behaviors in surface relaxation, that is both exhibit- expansions between the first two layers, are consistent with the experimental data. It is suggested- that these expansions are mainly due to the increase of electronic s state and the decrease of p state in the bonds between the first two layers.
MICROSTRUCTURE AND MAGNETIC PROPERTIES OF Fe-Si ALLOYS PREPARED BY-MECHANICAL ALLOYING
Authors: ZHOU TIE-JUN  , WANG DUN-HUI  , ZHANG JIAN-RONG  , DOU YOU WEI  , WANG JIN-HUI  , CHEN YUN-HONG  ,   (1)南京大学物理系固体微结构物理国家重点实验室; (2)扬州大学师范学院物理系
Published: December 2020

Some Fe-Si alloys have been prepared using the mechanical alloying method. The structure of the obtained Fe-Si alloys is the same as that of the bcc α-Fe. The final powders mainly consist of some particles with a grain size from a few hundreds of nanometers to several microns,while these particles are composed of some subgrains with a microcrystalline size of about 15—20 nanometers. Their magnetic properties have also been investigated. The values of their specific saturation magnetization (σs) are slightly less than those of the corresponding single crystalline and polycrystalline Fe-Si alloys, while the values of their coercive force (Hc) are nuch higher than those of corresponding Fe-Si alloys in bulk. Their magnetic spectra are all relaxation type except for Fe75Si25, and the values of their μ′ and μ″ are comparable with those of the ferrite composite materials and, in their magnetizing process, the domain wall displacements are predominant.
SECONDARY PORE STRUCTURE OF USY ZEOLITES STUDIED BY POSITRON ANNIHILATE TECHNIQUE
Authors: MA LI  , CHEN ZHI-QUAN  , WANG SHAO-JIE  , PENG ZHI-LIN  , LUO XI-HUI  ,   (1)抚顺石油化工研究院; (2)武汉大学物理系
Published: December 2020

The structures of NaY and ultrastability Y-type (USY) zeolite were studied by positron lifetime spectroscopy.Four lifetimes could be obtained in NaY zeolite,the two larger components were assigned to be o-Ps annihilation in the β cage and supercage respectively.In USY zeolite,however,an additional lifetime component τ5 was observed,which was about 92ns in vacuum with continuous distribution from 39ns to 142ns by the Laplace inversion analysis of lifetime spectrum.The second larger lifetimes τ4 also increased to 14ns,compared to that in NaY zeolite.Existence of the longer lifetimes τ4 and τ5 is due to the porous structure of USY.The positron lifetime in USY zeolite was also measured as a function of air pressure ranging from 0 (vacuum) to 0.1MPa.The most interesting was the variation of the largest components τ5 and I5.They both decreased with increasing air pressure.The results can be explained as follows.First,the oxygen contained in the air could quench the Ps and reduce its lifetime and intensity.Second,the increasing density of air could also increase the probability of o-Ps pick-off annihilation and reduce its formation.These would lead to the decrease of its lifetime and intensity.
PREPARATION AND INFRARED ABSORPTION PROPERTIES OF BURIED SiC LAYERS
Authors: YAN HUI  , CHEN GUANG-HUA  , S.P.WONG  , R.W.M.KWOK  ,   (1)北京工业大学应用物理系; (2)香港中文大学电子工程系; (3)香港中文大学化学系
Published: December 2020

Buried SiC layers were formed by using a metal vapor vacuum arc (MEVVA) ion source,with C＋ ions implanted into Si substrates under different doses.In the present study, the extracted voltage was 50kV and the ion dose was varied from 3.0×1017—1.6×1018cｍ-2.According to infrared absorption measurements,it was found that the structure of the buried SiC layers depended on the ion dose.Moreover,the results also demonstrated that the buried SiC layers including cubic crystalline SiC could be synthesized at an averaged substrate temperature of lower than 400℃ with the MEVVA ion source.
HAWKING RADIATION OF CHARGED DIRAC PARTICLES IN VAIDYA-BONNER-DE SITTER SPACE-TIME
Authors: MA YONG  , YANG SHU-ZHENG  ,   (1)四川师范学院物理系; (2)重庆师范学院物理系
Published: December 2020

The exact locations of the universe horizon and the outer and inner horizons of the black hole are given in the Vaidya-Bonner-de Sitter space-time.Hawking radiation of charged Dirac particles near the outer horizon and the universe horizon are studied.It is determined that any two of the three horizons cannot coincide.
SOME IMPROVEMENTS ON KELDYSH-FAISAL-REISS THEORY
Authors: CHEN BAO-ZHEN  ,   北京师范大学低能核物理研究所
Published: December 2020

How to insert the final Coulomb interaction into Keldysh-Faisal-Reiss theory is discussed in A guage. The correct low intensity behavior predicted by the improved theory and a brief comparison with that predicted in E guage, then, are shown. Finally, a comment on the numeric result is- given.
PHASE OPERATOR AND PHASE STATES FOR FINITE ENERGY SYSTEM
Authors: TAN WEI-HAN  , LIU JUAN  ,   上海大学物理系
Published: December 2020

In view of the divergent expectation value of photon number in Pegg-Barnett phase state,in this paper the phase operator,phase states for finite energy system are defined.Its orthogonality,completeness and application in the phase fluctuation calculation are studied.
ULTRAFAST OPTICAL KERR EFFECT AND OPTICAL INDUCED ABSORPTION OF EMERALDINE BASE
Authors: SHANG XIAO-MING  , WANG CONG-FANG  , WANG JING-JING  , ZOU YING-HUA  , YANG WEN-JUN  , SONG YAN-LIN  , LUO CHUAN-QIU  , CHEN HUI-YING  ,   (1)北京大学化学系; (2)北京大学物理系
Published: December 2020

The transient optical Kerr effect (OKE) and optical induced absorption of emeraldine base (EB) in dimethylformamide solution have been investigated with femtosecond laser pulses.Only a ultrafast component of OKE of EB solution is observed and its dephasing time is given by theoretical fitting.The third-order nonlinear optical susceptibility of EB solution is also determined.Two-photon absorption is proved to be the predominant mechanism causing the observed optical limiting behavior.
A NEW TYPE ACCELERATOR
Authors: ZENG GUI-HUA  , XU ZHI-ZHAN  ,   中国科学院上海光学精密机械研究所
Published: December 2020

A new type of accelerator scheme is proposed, which employs the combination of an intense laser field and a self-generated magnetic field. Theoretical analyses and numerical evalutions are performed.Results show that an electron injected can be efficiently accelerated in the combined field under the cyclotron resonance condition.
MEASUREMENT ON THE THERMO OPTIC COEFFICIENT dn/dT OF SEMICONDUCTOR PbS NANOPARTICLES AND THE STUDY ON THEIR OPTICAL LIMITING EFFECTS
Authors: YU BAO-LONG  , ZHU CONG-SHAN  , GAN FU-XI  ,   中国科学院上海光学精密机械研究所
Published: December 2020

We have measured the thermo-optic coefficient dn/dT and the thermal-induced index of refraction n２ of PbS nanoparticles in organosol with the single beam Z-scan technique. The optical limiting properties of PbS nanoparticles were studied under continuous wave laser illumination. Finally, the results obtained were analyzed and discussed.
ＥＮＥＲＧＹ ＴＲＡＮＳＦＥＲ ＡＮＤ ＵＰＣＯＮＶＥＲＳＩＯＮ ＩＮ Ｔｍ3+ ＡＮＤ Ｙｂ3+ ＣＯＤＯＰＥＤ ＺＢＬＡＮ ＧＬＡＳＳ
Authors: FENG YAN  , CHEN XIAO-BO  , HAO ZHAO  , ZHANG GUANG-YIN  , SONG FENG  , LI MEI-XIAN  ,   南开大学物理系
Published: December 2020

Ｕｎｄｅｒ ｔｈｅ ｐｕｍｐｉｎｇ ｏｆ ａ ９７０ｎｍ ｄｉｏｄｅ ｌａｓｅｒ ｔｈｅ Ｔｍ3+ ａｎｄ Ｙｂ3+ ｃｏｄｏｐｅｄ ＺＢＬＡＮ ｇｌａｓｓ ｅｍｉｔｓ ｓｔｒｏｎｇ ｂｌｕｅ ａｎｄ ｒｅｄ ｕｐｃｏｎｖｅｒｔｅｄ ｌｉｇｈｔ．Ｔｈｅ ｌｕｍｉｎｅｓｃｅｎｃｅ ｏｆ 1Ｇ4 and 3Ｆ4 ｌｅｖｅｌｓ ｒｅｓｕｌｔｓ ｆｒｏｍ ｔｈｅ ｃｏｎｓｅ-ｑｕｅｎｔｉａｌ Ｙｂ3+ ｔｏ Ｔｍ3+ ｅｎｅｒｇｙ ｔｒａｎｓｆｅｒ，ｗｈｅｒｅａｓ ｔｈｅ 1Ｄ２ ｌｅｖｅｌ ｉｓ ｅｘｃｉｔｅｄ ｂｙ ａ ｆｕｒｔｈｅｒ ｃｒｏｓｓ ｅｎｅｒｇｙ ｔｒａｎｓｆｅｒ ａｍｏｎｇ Ｔｍ3+ ｉｏｎｓ.Ｔｈｅ ｃｒｏｓｓ-ｒｅｌａｘａｔｉｏｎｓ ｏｆ Ｔｍ3+ ｉｏｎｓ ａｎｄ ｂａｃｋ ｅｎｅｒｇｙ ｔｒａｎｓｆｅｒ ｏｆ Ｔｍ3+ ｔｏ Ｙｂ3+ ｗａｓ ａｌｓｏ ｏｂｓｅｒｖｅｄ．Ｆｕｒｔｈｅｒｍｏｒｅ，ａｆｔｅｒ ａｎ ｉｎｖｅｓｔｉｇａｔｉｏｎ ｏｆ ｔｈｅ ｓｐｅｃｉａｌ ｃｈａｒａｃｔｅｒｉｓｔｉｃ ｏｆ Ｔｍ3+ ａｎｄ Ｙｂ3+ ｃｏｄｏｐｅｄ ｓｙｓｔｅｍ ｗｅ ｔｈｉｎｋ ｔｈａｔ ｔｈｉｓ ｓｙｓｔｅｍ ｉｓ ａｄｖａｎｔａｇｅｏｕｓ ｔｏ ｔｈｅ ｉｍｐｒｏｖｅｍｅｎｔ ｏｆ ｔｈｅ ｎｅｔ ｅｆｆｉｃｉｅｎｃｙ ｏｆ ｕｐｃｏｎｖｅｒｓｉｏｎ ｌｕｍｉｎｅｓｃｅ.
POTENTIAL ENERGY FUNCTION AND SPECTRUM CONSTANTS FOR THE B″3Πu STATE OF S2
Authors: TANG YONG-JIAN  , ZHAO YONG-KUAN  , ZHU ZHENG-HE  , FU YI-BEI  ,   (1)四川联合大学原子分子物理研究所，成都  610065; (2)四川联合大学原子分子物理研究所，成都  610065;中国工程物理研究院核物理与化学研究所，成都  610003; (3)中国工程物理研究院核物理与化学研究所，成都  610003
Published: December 2020

A reasonable dissociation limit of B″3Πu state of molecular sulfur (S2) has been derived,and a potential energy curve of B″3Πu and X3Σ-g states of S2 has been calculated by using Gaussian 94 QCISD(T) method and the 6-311++G** basic set function.The murrell-Sorbie potential energy function and spectrum constants are given.Because B″3Πu state overlap extensively with B3Σ-u state in the repulse branch and B″3Πu and X3Σ-g states have the same dissociate limits,they have an overlap in the attract branch.In this paper,the interaction characteristics of B″3Πu,B3Σ-u and X3Σ-g states have also been discussed.
A GENERALIZED BETHE ANALYTIC FORMULA: DIPOLE-EXCITED COLLISION STRENGTHS AND CORRESPONDING RATE COEFFICIENTS IN Au50+
Authors: FANG QUAN-YU  , CAI WEI  , ZOU YU  , LI PING  ,   北京应用物理与计算数学研究所，北京  100088
Published: December 2020

A generalized Bethe analytic formula for dipole-excited collision strengths is suggested, in which a cut-off k0 in the momentum transfer, a threshold (via extrapolation) and a thrice threshold of collision strengths for each dipole-excited process are calculated quickly based on the quasi-relativistic plane wave Born (QRPB) and distorted wave (QRDW) methods respectively. The formula can be applied to moderate and low impact electron energies. As a example, dipole collision strengths and corresponding rate coefficients of Au50+ are given at all impact energies, which are in agreement with that of a least-square spline method. Meanwhile the systems of k0 in channel n0l0→n(l0+1) are analyzed.
EXPERIMENTAL INVESTIGATION ABOUT THE GENERATION SYSTEM OF MULTIPLE NONCLASSICAL LIGHTS
Authors: PAN QING  , WANG HAI  , ZHANG YUN  , SU HONG  , XIE CHANG-DE  , PENG KUN-CHI  , YU ZHENG-GANG  , LU QING-MING  ,   (1)山东大学化学学院，济南  250100; (2)山西大学光电子研究所，太原  030006
Published: December 2020

The configuration of a semimonolithic continuous nondegenerate optical parameter oscillator consisting of an α-cut KTP crystal pumped by an intracavity frequency-doubled and frequency-stabilized Nd∶YAP laser is designed. Both two-mode quadrature-phase squeezing of 3.7dB and intensity-difference squeezing of 7dB have been generated from the cw-NOPO operating respectively below and above the oscillation threshold. The system can operate stably to generate the squeezed light for over half an hour.
EXPERIMENTAL AND NUMERICAL STUDY ON THE STABILITY OF COUNTER-ROTATING CIRCULAR COUETTE SYSTEM WITH THE INTERMEDIATE RADIUS RATIO
Authors: HE YU-QUAN  , LIANG BAO-SHE  , LIU SHU-SHENG  ,   天津大学应用物理学系，天津  300072
Published: December 2020

Circular Couette System has served as a paradigm for studying complex transitions to turbulence,the influence of finite geometry on pattern-selection mechanisms.In this paper stability of a circular Couette system with the intermediate radius ratio is investigated through laboratory experiments and computer simulation.The classical Rayleigh centrifugal instability theory is extended to general viscous,incompressible fluid between concentric independently rotating cylinders.A criterion of stability is formulated to quantitatively determine the stability boundary.The laboratory experiments employ the techniques of the laser light scattering and the flow visualization.The apparatus has a radius ratio of η=0.699 and an aspect ratio of Γ=18.A striking feature in phase diagram of flow states is the novel primary instability:when the outer cylinder is at rest,or counterrotating,instability occurs first for nonzero azimuthal wave number.Instead of time-independent Taylor vortex flow,the resulting flow is spiral vortices which are traveling waves in both the axial and azimuthal directions.Preliminary experimental measurements of transition Reynolds numbers presented here are in agreement with those obtained numerically.Laboratory and numerical experiments have revealed the effects of radius ratio on pattern formation,the sequence of transitions.
COMPUTER SIMULATION OF THE ELECTRON MOTION IN A HELIUM HOLLOW-CATHODE DISCHARGE CONFINED BY A MAGNETIC FIELD
Authors: CHEN YONG-ZHOU  , CHEN QING-MING  , LI JUN  , LAI JIAN-JUN  , QIU JUN-LIN  ,   华中理工大学激光研究院激光技术国家重点实验室，武汉  430074
Published: December 2020

In this paper,the electron motion confined by a transverse magnetic field in a hollow-cathode discharge is investigated.Some swarm paramaters are obtained such as the energy and spatial distribution under the terminative condition.Due to the existence of a transverse magnetic field,electrons' motion is changed and thus all kinds of the inelastic collision are different from the case of zero magnetic field.The results from simulation show that while the magnetic field is equal to 0.05T,the ionization increases and the distribution of the electrons and ions are of benifit to the development of ion laser.
A MATHEMATICAL MODEL OF SURFACE-PRESSURE-INDUCED SEPARATION OF CHIRAL PHASES IN MONOLAYER OF RACEMIC AMPHIPHILES AND ITS CLASSICAL SOLUTIONS IN TWO-DIMENSIONAL CASE
Authors: YANG SHI-XIN  ,   厦门大学数学系，厦门  361005;中国科学院理论物理研究所，北京  100080
Published: December 2020

The problem of the surface-pressure-induced separation of chiral phases in monolayer of racemic amphiphiles is studied.Following the work of Ou-Yang and his co-wokers published in “Chem.Phys.Lett.(1998)”,we give several classes of classical solutions in the two-dimensional case for the equilibrium equations for the chiral phases separation order parameter and the molecular orientation pattern.
ANALYSIS OF NEAR EDGE FINE STRUCTURE AND ELECTRONIC POPULATIONS IN SAPPHIRE
Authors: FAN XI-JUN  , TIAN SHU-FEN  , LI TIAN-PING  , J.S.BOW  , R.W.CARPENTER  , S.H.LIN  ,   (1)Center for Solid State Science,Arizona State University,Tempe,AZ85287,USA; (2)山东师范大学传播学院，济南  250014; (3)山东师范大学物理系，济南  250014
Published: December 2020

AlL and OK near edge fine structures in sapphire are studied using electron energy loss microspectroscopy in a transmission electron microscope;an analysis of the electronic populations of atoms Al and O,and a comparison between different partial cross sections are given.We consider the ionization of an atom in a homogeneous solid to interpret the elemental effects in the ionization region near edges.The chemical effects in the region near edge onset are interpreted by using extended Hückel molecular orbital theory and Bloch's theorem including the effects of translation symmetry in crystals to calculate the electronic transitions from core-shell to unoccupied valence-shell.We also consider the additional chemical effects, which arise from the elastic backscattering of the atomic ionization waves by the atoms neighboring the exited atom,giving rise to the so-called extended fine structure in the ionization region.The agreement between the calculated results and the experimental energy loss spectra of sapphire from single-phase region is good.
THEORETICAL ANALYSIS AND COMPUTER EXPERIMENTS FOR 1D RANDOM TRAFFIC FLOW MODELS
Authors: LV XIAO-YANG  , LIU MU-REN  , KONG LING-JING  ,   (1)广西师范大学物理与电子科学系,桂林 541001; (2)华南师范大学行政学院;广西师范大学物理与电子科学系
Published: December 2020

In this paper we present an entirely random traffic flow model by introducing brake, creation and disappearance probabilities into 1D local interactive cellular automota. By means of epuilibrium spin theory, we find that when Pin=Pout≠0, the final density of the model is ρｔ＝0.5 and indepen-dent of initial density distribution. When the conditions Pin+Pb=1 and Pin=Pout are satisfied, we get a simple “linear” traffic flow model that displays long distance correlation under the condition |1-2Pin|=1 and leads to a serious traffic jam. The cemputer simulation results agree with the the-oretical prediction.
DETERMINATION OF 3d AND 5s RYDBERG STATES OF SF2 RADICAL
Authors: ZHANG QUN  , SHU JI-NAN  , XIE LI-LI  , DAI JING-HUA  , ZHANG LI-MIN  , LI QUAN-XIN  ,   中国科学技术大学化学物理系,合肥 230026;中国科学院选键化学开放研究实验室,合肥 230026
Published: December 2020

A pulsed dc discharge in a pulsed supersonic beam has been developed as an efficient source of producing free radicals. Spectra of the SF2 radical were observed between 272 and 294 nm by (2+1) resonance-enhanced multiphoton ionizition (REMPI) spectroscopy. Vibrational progressions associat-ed with 3d and 5s Rydberg states were assigned. The spectroscopic values ω＇1 (a1, symmetric stretch-ing), band origin T0 and quantum defect δ of these Rydberg states were reported.
THE RADIAL PROFILE OF C6+ ION IN HT-6M TOKAMAK
Authors: XU WEI  , WAN BAO-NIAN  ,   (1)广州师范学院物理系,广州 510400; (2)中国科学院等离子体物理研究所，合肥 230031
Published: December 2020

The line shape of CⅥ 207.1nm has been measured with optical spectroscope multichannel analyzer on HT-6M Tokamak. The result of the analysis of line shape showed that CⅥ 207.1nm line emission arised mainly from the charge exchange-recombination processes. The temporal behavior of CⅥ line emission also proved this conclusion. The radial profile of C6+ ion has been deduced from the measurements of neutral hydrogen density and the volume emission coefficient of CⅥ 207.1nm line emission.
EMPIRICAL PARAMETERIZATION OF INTER-IONIC POTENTIALS FOR ALKALINE EARTH FLUORIDES
Authors: FENG SHAO-XIN  , JIN QING-HUA  , GUO ZHEN-YA  , LI BAO-HUI  , DING DA-TONG  ,   南开大学物理系，天津 300071
Published: December 2020

When the functional forms of non-coulombic inter-ionic short-range potentials have been defined, the bulk properties of ionic crystals can be calculated. The parameters presented in potential functions are determined by fitting procedure, to reproduce as colsely as possible the measured crystal data. In the present study, the shell model is employed for the investigations of CaF2, SrF2 and BaF2 ionic crystals. Remarkable feature of the present fitting procedure is that shell charges are sure to be negative and recent experimental data are adopted. The anion (F-) charge, which is assumed to be common to the three fluorides, is adjusted to 0.97e. In so doing, the obtained model parameter set is able to produce a satisfactory agreement between the calculated results and the experimental data, such as lattice formation energies, elastic constants, dielectric constants, ionic polarizabilities, transverse optic and Raman frequencies, for the alkaline earth fluorides.
AB INITIO INVESTIGATIONS IN ORGANIC FERROMAGNET
Authors: FU RONG-TANG  , WANG XIAO-DONG  , SUN XIN  , Y.KAWAZOE  ,   (1)东北大学金属材料研究所，仙台 980-77,日本; (2)复旦大学物理系，上海 200433
Published: December 2020

“A Full Potential Linearized Augmented Plane Wave” scheme is applied to the study of the electronic and magnetic features on a simple organic ferromagnet modified by an organic high-spin segment (CH2) to trans-polyacetylene. Some physical quantities, i.e., band structure, the total and partial spin densities of states, magnetic moment and splitting energy, are shown quantitatively in our report. An anti-ferromagnetic order is expected and a specific π orbital is announced to be important for the magnetic features in an organic ferromagnet.
A HIGH RESOLUTION ELECTRON MICROSCOPY INVESTIGATION OF CURVATURE IN MULTILAYER GRAPHITE SHEETS
Authors: WANG ZHEN-XIA  , HU JUN  , WANG WEN-MIN  , YU GUO-QING  , RUAN MEI-LING  ,   (1)中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海 200050; (2)中国科学院上海原子核研究所，上海 201800
Published: December 2020

Here we report a carbon sample generated by sonicating high oriented pyrolytic graphite (HOPG) in ethanol, water or ethanol-water mixed solution. High resolution transmission electron microscopy (HRTEM) revealed many multilayer graphite sheets with a total curved angle that is multiples of θ0(=30°). Close examination of the micrographs showed that the curvature is accomplished by bending the lattice planes. A possible explanation for the curvature in multilayer graphite sheets is discussed based on the conformation of graphite symmetry axes and the formation of sp3-like line defects in the sp2 graphitic network.
CALCULATION OF THE ATOMIC GEOMETRIES AND ELECTRONIC PROPERTIES OF ZnS (110) SURFACE
Authors: XHEN SAN-GUO  , JIA YU  , MA BING-XIAN  , FAN XI-QING  ,   郑州大学物理工程学院,郑州 450052
Published: December 2020

The total-energy minimization method is applied to the determination of the surface structure of the ZnS(110) surface. The predicted surface atomic geometry agrees well with that obtained from elastic low-energy electron diffraction intensity analysis. The electronic structure of ZnS(110) surface has been studied by using the method of Green's function scattering theory. Our results are eonsis-tent with the first principle calculations, and the influence of lattice relaxation on surface electronic properties are discussed.
THE MECHANISM OF PYROELECTRIC EFFECT IN ULTRATHIN MOLECULAR ORGANIZED FILMS OF HEMICYANINE DYES
Authors: YAN MEI  , MA SHI-HONG  , LIU LI-YING  , WANG WEN-CHENG  , CHEN ZHANG-HAI  , LIU PU-LIN  ,   (1)复旦大学物理系三束材料改性国家重点实验室,上海 200433; (2)中国科学院红外物理国家重点实验室
Published: December 2020

The ultrathin molecular organized films of hemicyanine dyes were prepared by langmuir-Blod-gett technique. The films show ferroelectric hysteresis loop and pyroelectric effect. The pyroelectric coefficient measured by the method of integrated charges is 12μC·m-2·K-1 at 300 K, and the relationship between the orientaton of DAEP in the films and temperature was studied by polarized FTIR spectroscopy. The microscopic mechanism of pyroelectricity in the films was discussed.
A MOLECULAR DYNAMICS STUDY OF THE CHEMISORPTION OF C2H2 ON THE DIAMOND (001)-(2×1) SURFACE
Authors: ZHU WEN-JUN  , PAN ZHENG-YING  , HUO YU-KUN  ,   (1)复旦大学现代物理研究所基于加速器的原子物理和原子核物理开放研究实验室,上海 200433; (2)复旦大学现代物理研究所基于加速器的原子物理和原子核物理开放研究实验室,上海 200433；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; (3)复旦大学现代物理研究所基于加速器的原子物理和原子核物理开放研究实验室,上海 200433；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；大连理工大学三束材料改性国家重点实验室地，大连 116024
Published: December 2020

The chemisorption of acetylene molecules on a reconstructed diamond (001)-(2×1) surface and the dynamic behavior of this reaction are studied by molecular dynamics simulation using many-body interatomic Brenner (#2) potential. Six chemisorption configurations are observed. About 95% of the chemisorption events invole the formation of two C—Cs bonds between the acetylene molecule and the diamond surface. The dependence of the adsorption configuration upon the binding energy, the incident energy and the position of the molecule, as well as the local spatial structure of the diamond surface are analyzed. In order to provide an intensive understanding of the chemisorption, snapshots of atomic position are provided. The energy exchange characteristics between the incident molecules and the surface are discussed.
NUCLEAR CLUSTER EFFECT IN THE INTERACTION OF DEUTERIUM CLUSTER ION (d+3) AND SOLID (PdDx)
Authors: WANG  TIE-SHAN  , KENTARO OCHIAI  , KATHUHIKO MARUTA  , TOSHIYUKI IIDA  , AKITO TAKAHASHI  ,   (1)日本国大阪大学原子力工学系，大阪  565，日本; (2)中国科学院近代物理研究所，兰州  730000
Published: December 2020

The deuterium cluster-ion, which consists of three deuterons, was used to study the cluster effect in the D-D fusion reaction in solids. The cluster-ion beam (deuteron-cluster d+3) and isolated deuteron (single deuteron d+), whose energies were adjusted as from 10 to 100keV per deuteron, were alternatively implanted into deuterium-palladium target. The differences of the fusion reaction rates were obtained by comparing the radiation yields of charged particles and neutrons that were induced by two kinds of beams with the same velocity. Experimental results are as follows: Each deuteron of cluster-ion (cluster deuteron) induced higher D-D fusion rate, compared with an isolated deuteron, when the deuteron energy was lower than 40keV per deuteron; while the cluster deuteron induced lower fusion rate when its energy was higher than 50keV per deuteron. The ratio of fusion rate induced by cluster deuteron to that induced by isolated deuteron decreased with the increase of deuteron energy. Some interpretations have been discussed.
DEFLECTION CHARACTERISTICS OF SPLIT ELECTRODE INPLANE BENDING PIEZOELECTRIC ACTUATORS WITH VARYING WIDTH
Authors: WANG ZHI-HONG  , TIAN XIAO-GENG  , WANG SAN-HONG  , YAO XI  ,   (1)西安交通大学电子材料与器件研究所，西安  710049; (2)西安交通大学工程力学系，西安  710049
Published: December 2020

The cantilever split-morph, a new type of piezoelectric actuator, have been designed for dual-stage head positioning servo system of high density hard disk drives. In this actuator configuration, a PZT ceramic plate, with one end mechanically clamped and the other free, was poled along its thickness and divided into two symmetric parts along length by splitting electrodes. Driving voltages are preferably so arranged that they make one of the two parts expand by the “31”action while the other part, i.e., the symmetric part, contracts. This will result in a bending motion of the actuator along the direction of its width. The driving voltage-tip displacement characteristics of the actuator have been investigated by theoretical analysis, finite element modeling and experiment. Theoretical analysis indicated that the electric field induced stress is much smaller than stretch strength of piezoelectric ceramic. Tip displacement measured by Michelson interferometer is a little larger than the calculated result. This is mainly due to the increase of piezoelectric coefficient d31 at high driving field. Tip displacement of 1 to 2μm can be achieved at 20 to 50V driving voltage for the split-morph whose size is similar to that of the existing suspension. As to 25 kTPI (track per inch) high track density hard disk drives, this actuating stroke can cover at least one track width and meet the primary requirements of dual-stage head positioning servo system for displacement of the secondary actuator.
The Influence of Particle Size on Magneto-Optical Kerr Effect in Fe45Ag55 Granular Films
Authors: Wang Hui  , Zhao Hai-Bin  , Wang Song-You  , Shen Zuo-Cheng  , Zhang Rong-Jun  , Chen Liang-Yao  ,   (1)复旦大学材料科学系，上海 200433; (2)复旦大学物理系，上海 200433
Published: December 2020

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Calculation of Magnetic Entropy Changes of Gadolinium from Magnetization Curves
Authors: Li Zhuo-Tang  , Wu Pei-Fang  , Tao Yong-Qi  , Mao De-Kang  ,   (1)上海大学无机材料系，上海 201800; (2)上海跃龙有色金属有限公司，上海 200949
Published: December 2020

The magnetization curves of gadolinium were measured with a vibrating sample magnetometer, from which the function M(H,T) was obtained using two-step least square fitting. Then magnetic entropy changes can be calculated. These works can provide the perliminary information needed for the design of magnetic refrigerator.
Study of the Anisotropy of Microwave Electromagnetic Parameters of Polycrystalline Iron Fiber Absorber
Authors: He Hua-Hui  , Wu Ming-Zhong  , Zhao Zhen-Sheng  ,   华中理工大学电子科学与技术系，武汉 430074
Published: December 2020

Based on Maxwell equations, the theoretical formulas of microwave electromagnetic parameters of polycrystalline iron fiber absorber are dervied. The anisotropy of microwave electromagnetic parameters of polycrystalline iron fiber absorber is explained by use of numerical calculations. Some samples of fiber orientation have been produced and their electromagnetic parameters have been tested, the results confirm the anisotropy of electromagnetic parameters. Both of the theoretical and experimental results demonstrate that the axial permeability of polycrystalline iron fiber is greater than its radial permeability, and the axial permittivity of polycrystalline iron filber is greater than its radial permittivity.
Quantum Phase Transition in a Bilayer Heisenberg Antiferromagnet
Authors: Yu Deng-Ke  , Gu Qiang  , Wang Han-Ting  , Shen Jue-Lian  ,   中国科学院物理研究所，北京　100080
Published: December 2020

In this paper we use a bond-operator mean-field theory to study the quantum phase transition in the bilayer Heisenberg antiferromagnet. The obtained critical point and low temperature quantum critical behavior are consistent with the numerical results and the nonlinear σ model results. In the very low temperature (T≤0.3J1, J1 is the in-plane antiferromagnetic coupling), where the numerical results are not available, present paper gives new evidence for the quantum critical behavior.
THE STUDY OF MULTI-DROMION STRUCTURES AND INTERACTIONS OF (2+1)-DIMENSIONAL NLBQ EQUATION AND KP EQUATION
Authors: RUAN HANG-YU  ,   宁波大学师范学院物理系，宁波  315211；浙江大学近代物理中心，杭州  310027
Published: December 2020

Starting from two-line soliton solution of an integrable (2+1)-dimensional system in bilinear form,one can find a dromion solution that is localized in all directions for a suitable potential.The in-teraction between two dromions is studied in detail through the method of figure analysis for (2+1)-dimensional NLBQ equation and KP equation.Except for a phase shift,there are no changes on the shape and velocity of the dromions after interactions for these models.The interactions of dromions for these models are not only elastic (there is no exchange of energy)but also irrotational (there is no exchange of angular momentum).
REDUCTION OF NOISE IN CHAOTIC SYSTEMS BY WAVELET MULTISCALING DECOMPOSITION ALGORITHM
Authors: HUANG XIAN-GAO  , XU JIAN-XUE  , HE DAI-HAI  , XIA JUN-LI  , LV ZE-JUN  ,   (1)空军电讯工程学院,西安  710071; (2)西安交通大学非线性动力学所,西安  710049; (3)重庆大学应用数学系,重庆  630044
Published: December 2020

We apply the wavelet multiscaling decomposition algorithm,which has been developed for noise reduction,to the extraction of periodic signal,noise and other chaotic signal from chaotic back-ground.This algorithm utilizes the characteristic that wavelet transform has an outstanding local fea-ture in time-frequency domains and it is a linear transform.Therefore it can distinguishes signals with different scales.In contrast to the previous methods our method uses the feature of signal scales and dose not demand restrictive assumptions that we must know the mathematical model of the chaotic background and that the amplitude of signal is smaller than that of the chaotic background.The re-sults of computer simulation are given for extracting the sine signal,white noises (distributed uni-formly or in Gaussion shape) and Chua's chaotic signal from Lorenz chaotic back ground.
TUNABLE FREQUENCY-SELECTIVE CONVERTER FOR HIGH-SPEED DWDM SYSTEMS
Authors: JIANG YAN  , CUI YI-PING  , PANG SHU-MING  ,   东南大学电子工程系，南京  210096
Published: December 2020

A kind of tunable frequency-selective converter based on nondegenerate four-wave mixing (ND-FWM) in semiconductor laser amplifier (SLA) is proposed in this paper.The coupling model of the frequency-selective converter in SLA is established first,and then the converting mechanism and characteristics are analyzed.The influences of its property parameters on the output efficiency,and the frequency shift are primarily discussed.And the property of the output noise of the frequency-se-lective converter has been studied as well.The superior performance of the converter,such as short response time,high conversion efficiency,and large conversion range,makes it favorable for use in DWDM networks where high speed and tunableness are required.
THEORETIC CALCULATION ON THE ELECTRONIC STRUCTURE OF PbWO4 CRYSTALS
Authors: YE XIAO-LING  , YANG XIAO-YU  , SHI CHAO-SHU  , GUO CHANG-XIN  ,   (1)中国科学技术大学国家同步辐射实验室，合肥  230026; (2)中国科学技术大学国家同步辐射实验室，合肥  230026；中国科学技术大学物理系，合肥  230026; (3)中国科学技术大学物理系，合肥  230026
Published: December 2020

The electronic structure in UV-VUV region of PbWO4 crystaly is studied in a molecular-cluster model within the framework of the fully relativistic self-consistent Dirac-Slater theory,using a nu-merical discrete variational (DV-Xα) method.From the calculation,the fundamental gap is found to be around 4.4eV,the top of valence band is formed almost purely by O 2p and has certain Pb 6s component in the band,W 5d is at the bottom of the conduction band,Pb 6s narrow band is just be-low the valence band.These results are in reasonable agreement with experimental data measured in the fundamental absorption region using VUV synchrotron radiation.
CALCULATION OF THE PHASE DIAGRAM FOR MAGNETIC ALLOY FILM
Authors: ZHOU YUN-SONG  , QU XIAO-FENG  , LIN DUO-LIANG  ,   (1)美国纽约州立布法罗大学物理系，美国，布法罗  14260; (2)首都师范大学物理系，北京  100037
Published: December 2020

VCE method was extended to treat antiferromagnetic-paramagnetic transition,so that it is not only able to calculate the Curie temperature but also the Neel temperature.The formulas for calculat-ing critical temperatures of random-bound layered Ising model,which describes the phase transition in magnetic alloy film,were provided.Some Tc-χ phase diagrams for magnetic alloy film were investi-gated and discussed.
EXPLICIT EXACT SOLUTIONS FOR NONLINEAR APPROXIMATE EQUATIONS WITH LONG WAVES IN SHALLOW WATER
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,the nonlinear approximate equations for long wave in shallow water are studied via using two different methods.Firstly,with the aid of Mathematica and Wu-elimination method,by using sine-cosine method,three families of soliton solutions are obtained.Secondly,based on the known references,through using a new transformation,several rational formal solutions are found again.The two methods can be also applied to other nonlinear equations.
THE THEORY OF THE PERTURBATION EQUATION OF MKdV
Authors: ZHAO  YONG-MING  , YAN JIA-REN  ,   湖南师范大学物理系，长沙  410006
Published: December 2020

In this paper,we obtain the general expression of the first-order correction of the Perturbation Equation of MKdV and give the exact expression of a special example.
Exchange Coupling in Ni81Fe19/Cr82Al18 Bilayers
Authors: Xia Guo-Qiang  , Zhou Shi-Ming  , Wang Song-You  , Chen Liang-Yao  ,   复旦大学物理系，上海 200433
Published: December 2020

In Py/CrAl bilayers (where Py=Ni81Fe19), the coercivity at room temperature is found to be a linear function of 1/t3/2FM, indicating the existence of random exchange interaction at the FM/AFM interface (FM=ferromagnetic, AFM=antiferromagnetic). The AFM layer thickness dependencies of the He and Hc are also studied.
CO LASER MAGNETIC RESONANCE SPECTRUM OF 15N16O AND ITS ANALYSIS WITH SPECTRA OF 15N17O AND 15N18O
Authors: LIU HONG-PING  , GUO YUAN-QING  , LIU XIAO-YONG  , LIN JIE-LI  , LI FENG-YAN  , LI JIN-RUI  , LIU YU-YAN  ,   中国科学院武汉物理与数学研究所波谱与原子分子物理国家重点实验室，武汉  430071
Published: December 2020

Employing the intracavity absorption technique,Lamb dip of the spectrum was obtained and the resolution and sensitivity of CO Laser magnetic resonance(LMR) spectrometer was greatly improved. By this technique, the X2Π3/2(υ=1←0) Zeeman transitions of 15N16O were observed with the Λ-doubling and hyperfine structures resolved. A correlative analysis of the LMR Spectrum of 15N16O with the previous available measurements was performed. The global least-square fit provided by far the most complete and the most accurate molecular constants of all the related isotopic species of 15NmO(m=16—18). The accuracy of these constants is improved by 1 or 2 orders. Many of the molecular constants including γ, AD, Δ01, Δ10, Δ00 were determined for the first time.
THE SUPER-QUADRATIC RELATION BETWEEN FREQUENCY DOUBLING EFFICIENCY AND POLING VOLTAGE IN SiO2-GeO2 THIN FILMS
Authors: XU ZHI-LING  , LIU LI-YING  , YANG PENG  , HOU ZHAN-JIA  , XU LEI  , WANG WEN-CHENG  ,   复旦大学三束材料改性国家重点实验室，物理系，上海  200433
Published: December 2020

Sol-gel method was used to prepare SiO2-GeO2 films. By investigating the second-harmonic generation signal of the film after parallel plate poling and corona poling, it was found that the number of effective dipoles in the sample increased with the plate poling voltage. A model of the release of effective dipoles was proposed to explain the super-quadratic relation between the second-order nonlinearity and the poling voltage.
INVESTIGATION OF THE NOVEL CARBON NANOSTRUCTURES BY HIGH RESOLUTION ELECTRON MICROSCOPY
Authors: WANG ZHEN-XIA  , RUAN MEI-LING  , YANG JIN-QING  , WANG WEN-MIN  , YU GUO-QING  ,   (1)中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室，上海  200050; (2)中国科学院上海原子核研究所，上海  201800
Published: December 2020

Flattened carbon nanoshells,carbon nanorods, and nanostructures of rod-tube have been observed in the cathodic doposits produced by a double-anode arc-discharge. As confirmed by high resolution transmission electron microscope (HRTEM), the growth of a carbon nanotube was directly linked to the nanorod, so the origin and development of nanotube seed is clearly discernible. In addition, the multishelled carbon nanorods HRTEM images revealed an isolated center line. We consider that such a line is probably a linear acetylenic carbon allotrope based on “sp” hybridization containing triple and single bonds.
THE EFFECT OF ATOMIC OF HYDROGEN IN THE INITIAL PROCEDURE OF DIAMOND HETEROEPITAXY ON Si AND THE INTERFACE BETWEEN DIAMOND AND Si
Authors: KANG JIAN  , XIAO CHANG-YONG  , XIONG YAN-YUN  , FENG KE-AN  , LIN ZHANG-DA  ,   (1)北京大学物理系，北京  100871; (2)中国科学院物理研究所表面物理国家重点实验室，北京  100080
Published: December 2020

The effect of atomic hydrogen on C2H2-covered Si surface was studied by high resolution electron loss spectroscope and low energy electron diffraction, the findings was that atomic hydrogen broke up C—C bond in C2H2 and the Si—Si dimer to form C—H，Si—H respectively. According to experimental phenomena, several cluster models were devised for quantum chemistry calculation. The calculation results agreed to experiment well and the discussions on the reaction sites of C2H2 adsorbed on Si(100) surface and the role of atomic hydrogen and nucleation mechanisn of diamond hetereopitaxy on Si were performed.
A PHENOMELOGICAL MODEL FOR FERROELECTRIC SUPERLATTICES
Authors: XU XIAO-HU  , SHEN JIAN  ,   南京大学物理系，南京  210093
Published: December 2020

We introduce a phenomelogical model to describe the characters of ferroelectric superlattices.Three kinds of coupling ways are considered in the model.The polarization,Curie temperature and the critical size of the superlattices are obtained by computational simulation.We think that the coupling coefficients are functions related with the temperature and the lattice size.An experience formula is introduced to explain recent experimental results about the KTaO3/KNbO3 superlattice material.
SUPERCRITICAL PROPERTIES OF A RELAXATION OSCILLATOR
Authors: WU SHUN-GUANG  , DING XIAO-LING  , MA MING-QUAN  , YIN YUE-CAI  , NIN JIAN-JUN  , QU SHI-XIAN  , HE DA-REN  ,   (1)北京师范大学低能核物理研究所，北京  100875; (2)沈阳师范学院物理系，沈阳  110031; (3)西安电子科技大学物理系，西安  710068; (4)西安石油学院基础部，西安  710061; (5)西安市高新技术开发区企划部，西安  710075; (6)扬州大学理学院物理系，扬州  225002
Published: December 2020

In this paper we present the analytic expressions of partition lines in the parametric space of a piece-wise smooth mapping describing an electronic relaxation oscillator. The supercritical regions with permission of period-doubling bifurcation, prohibition of period-doubling bifurcation, and complete phase-locking are discussed. Among them the region, where period-doubling bifurcation is prohibited but chaos is permitted is reported for the first time to our knowledge. These kinds of phenomena and regions can be observed in a lot of similar systems.
REGIONAL FRACTAL AND ARTIFICIAL OBJECT DETECTION
Authors: MA ZHAO-MIAN  , TAO CHUN-KAN  ,   南京理工大学电光学院，南京  210094
Published: December 2020

Artificial object detection and segmentation in natural background are key points of pattern recognition and computer vision.The effect of complex texture of natural background and other factors,make it difficult to segment artificial object from natural background.In this paper,an algorithm based on watershed transform and regional fractal texture analysis is proposed to detect and segment artificial object from natural background.
LIQUID HYDROGEN ISOTOPES LAYER PROFILE INSIDE A CRYOGENIC INERTIA CONFINEMENT FUSION CAPSULE FOR AN ISOTHERMAL ENVIRONMENT
Authors: TANG YONG-JIAN  , ZHAO YONG-KUAN  , JIANG WEI-YANG  , ZHU ZHENG-HE  , LIU YUAN-QIONG  ,   (1)四川大学原子与分子物理研究所，成都  610065; (2)西南核物理与化学研究所，绵阳919信箱，绵阳  621900
Published: December 2020

It has been shown that the Young-Laplace equation based on the balance of the gravitational force and interfacial tension alone cannot produce a valid solution for the profile of a continuous liquid hydrogen layer inside an inertia confinement fusion capsule shell. In the calculated results, the London-van der Waals forces between the liquid and solid (shell) molecules must be included in the equation. The retardation effect of the London-van der Waals forces needs to be taken into account for thick liquid hydrogen isotopes layers. It has been also shown that, in an isothermal environment, a continuous liquid hydrogen isotopes layer with a uniform thickness can only be achieved inside the capsule shell, such as the spherical glass when the gravity is zero or the London constant between the solid and liquid molecules is infinity.
ABNORMAL TEMPERATURE FLUCTUATION OF STAINLESS STEEL IRRADIATED BY CW CO2 LASER
Authors: WEI XUE-QIN  , ZHENG QI-GUANG  , GU JIAN-HUI  , LI ZAI-GUANG  ,   华中理工大学激光技术国家重点实验室，武汉  430074
Published: December 2020

The temperature fluctuation of the stainless steel irradiated by a CW CO2 laser is studied. In the experiment, the temperature fluctuation and the temperature rise is measured by the infrared thermal imagers. It is found that the maximum amplitude of the temperature fluctuation is kept constant with the increase of the laser heating time; this is different from aluminum, low carbon steel, epoxylite and polymethylmethacrylate. This characteristic of the stainless steel is determined by the variance of thermal conductivity and thermal diffusivity with the increase of temperature. A thorough study of the effects of the material thermal properties on the temperature fluctuation is needed.
FLOQUET ANALYSIS FOR PATTERNS ON THE SURFACE OF FLUID SUBJECT TO DOUBLE-FREQUENCY EXCITATION
Authors: CHEN WEI-ZHONG  , WEI RONG-JUE  ,   南京大学声学研究所和近代声学国家重点实验室，南京  210093
Published: December 2020

The dynamical behaviors of onset patterns on the surface of viscous liquid in the large-aspect-ratio container under double-frequency parametric excitation have been investigated theoretically.The calculation shows the lower margin curves of exciting acceleration for pattern formation,the response modes and the frequency spectra of the pattern as well.Furthermore,the bicritical phenomenon found in the double-frequency Faraday experiments is also studied.All of the results from the theoretical calculation are in excellent agreement with those measured by Edwards et al. without any adjustable parameter.
TRANSFORMATION OF PHOTOEXCITATION IN POLYMERS UNDER AN ELECTRIC FIELD
Authors: JIANG HAO  , XU XIAO-HUA  , SUN XIN  , FU ROU-LI  , CHU JUN-HAO  ,   (1)红外物理国家重点实验室,中国科学院上海技术物理研究所,上海  200083; (2)李政道物理学综合实验室，复旦大学物理系,上海  200433
Published: December 2020

In this paper we simulate the phenomenon “field-induced charge generation” observed in polymers by means of molecular dynamics, and present the time-dependent evolution of bond structure and charge distribution of the polymer chain. The relaxation time of the transformation of one exciton into a couple of polarons is also determined.
Study on Ni80Fe20/Al2O3/Co Magnetic Tunnel Junctions
Authors: Du Jun  , Chen Jing  , Wu Xiao-Shan  , Pan Ming-Hu  , Long Jian-Guo  , Zhang Wei  , Lu Mu  , Zhai Hong-Ru  , Hu An  ,   (1)南京大学物理系，固体微结构物理国家重点实验室，南京 210093; (2)南京大学现代分析中心，南京 210093
Published: December 2020

With plasma oxidization to create an insulating layer of Al2O3, we have repeatedly fabricated some Ni80Fe20/Al2O3/Co magnetic tunnel junctions (MTJ), which show obvious tunneling magnetoresistance (TMR) effect. The insulating layer is well formed by the oxidization procedure, which is verified by optical spectra and other measurement results. At room temperature, the maximum TMR ratio reaches 6.0%. The switch field can be less than 800A/m and the relative step width is about 2400A/m. The junction resistance Rj changes from hundreds of ohms to hundreds of kilohms and TMR ratio decreases monotonously with the increase of applied junction voltage bias (under zero magnetic field).
THEORETICAL STUDY OF THE STRUCTURE AND MAGNETISM OF Co1-xMnx ALLOYS
Authors: LIU GUO-LEI  , JING CHAO  , WU DI  , WU YI-ZHENG  , DONG GUO-SHENG  , JIN XIAO-FENG  ,   复旦大学应用表面物理国家重点实验室，上海  200433
Published: December 2020

The magnetism of Co1-xMnx alloys strongly depends on their structure and the Mn content.An ab initio linearized augmented plane wave (LAPW)method has been carried out to provide the electronic and magnetic structures for the fcc and bcc Co1-xMnx alloys with x=0.00,0.25,0.50,0.75 and 1.00. By increasing the Mn content,the magnetism of fcc Co1-xMnx alloys changes from ferromagnetism to ferrimagnetism,finally to antiferromagnetism;on the other hand, the magnetism of bcc Co1-xMnx alloys changes from ferromagnetism to ferrimagnetism.A good agreement is reached between out calculations and the previous experimental results.