bluuebunny/crossref_metadata_2025 huggingface dataset:
Addressing Students’ Need in Mixed Ability Intercultural Classrooms: An Examination of Teachers’ Perspectives and Practices of Interculturally Differentiated Teaching
Authors: Neophytou Lefkios , Valiandes Stavroula , Hajisoteriou Christina
Published: December 2020

The challenge teachers and schools face nowadays is twofold: adopting an intercultural education framework and introducing high-quality teaching that will provide an equal opportunity for learning to all students, regardless of their ethnic origin or other characteristics. In this context,
after we introduce the framework of Interculturally Differentiated Teaching (IDT), we examine the implementation of IDT in real classroom settings that are characterised by both mixed ability and cultural diversity. Drawing upon interview and observation data, we examine how teachers attempt
to deal with this twofold challenge by focusing on their practices, the barriers they face, and their suggestions. Our findings caution that teachers are rather ill-prepared to deploy differentiated instruction in order to address both the goals of cultivating intercultural competence and
maximising the learning potential for all their students. Our research bears wider implications, suggesting that for IDT to be successfully implemented in practice, education policy should promote comprehensive approaches of intercultural education and differentiated instruction, both in terms
of teaching and teacher training.
Eigenenergies and wave functions of the Tavis-Cummings system driven by an external classical coherent field
Authors: Wang Zhong-Chun  , Wang Qi  , Gu Yong-Jian  , Guo Guang-Can  ,   (1)盐城师范学院物理系,盐城  224002;电子科技大学物理电子学院,成都  610054; (2)中国科学技术大学量子信息重点实验室,合肥  230026; (3)中国科学技术大学量子信息重点实验室,合肥  230026;盐城师范学院物理系,盐城  224002
Published: December 2020

We study the interaction of the atoms in the two-atom Tavis-Cummings (T-C) model under an external classical driving field. The eigenenergies - quasienergies and eigenstates of the T-C system driven by the external field are calculated i n the interaction picture. We also give the general wave function of the system in the Schrdinger picture. We show that the driving field does not change the energy levels of the T-C model, but makes the Fock states displaced. A stationar y state with a definite frequency in the normal two-atom T-C model is transform ed into the Fock states with infinite frequencies by the driving field.
Anomalous diffusion and fractional advection-diffusion equation
Authors: Chang Fu-Xuan  , Chen Jin  , Huang Wei  ,   长江水利委员会长江科学院，武汉430010
Published: December 2020

Anomalous diffusion happens often in nature and society systems. In this paper, we develop a nonlocal method with temporal and spatial correlations to introduce a fractional order advectiondiffusion equation based on the usually used local 2_nd order advectiondispersion equation. In this equation, the diffusion is a fractional order derivative of time and space. And then, we extend the classical Fick's law for standard diffusion to a general fractional Fick's law. The fractional Fick's law shows that the current is related to the concentrations all over the space, also depends on the previous history and the initial condition. The solution of this fractional order advectiondispersion equation is fractional Lévy probability distribution density. And the mean square displacement is a nonlinear function of time.
Stochastic resonance behaviors of bistable systems connected in series
Authors: Leng Yong-Gang  , Wang Tai-Yong  , Guo Yan  , Wang Wen-Jin  , Hu Shi-Guang  ,   (1)山东工商学院信息与电子工程学院，烟台264005; (2)天津大学机械工程学院，天津300072; (3)天津大学机械工程学院，天津300072;山东工商学院信息与电子工程学院，烟台264005
Published: December 2020

The stochastic resonance(SR) characteristics of two bistable systems connected in series have been investigated. It is deduced that the first bistable system of the cascaded system is most important because of its converting a white noise into a color one, and the subsequent bistable systems continuously concentrate noise energy into lowfrequency area in terms of Lorentzian distribution, which weakens the highfrequency dithering of the last output waveform and outlines the basic shape of the wave. The law of the signal spectral amplitude varying with noise intensity indicates that within a limited lowfrequency band, the cascaded system is able to promote the height of the signal spectral spike by a certain amount of noise. If the former of the cascaded system does not stay in SR, the latter could not optimize the former output to become a SR state. With the increase of the number of the bistable systems in the cascaded system, the lowfrequency area where most of the noise energy is collected will be narrowed gradually, and hence the signal peak is easily reduced and submerged in noise. For this case, in spite of using the twice-sampling technique to improve the signal spectral spike, the improvement is limited. Therefore, a single bistable system is effective for signal detection.
Interaction between a trapped ion with a single-mode quantized radiation field
Authors: Qu Zhao-Jun  , Liu Sheng-Dian  , Yang Chuan-Lu  ,   烟台师范学院物理系，烟台  264000
Published: December 2020

The statistical properties of the system consisting of a trapped ion and a single_mode quantized radiation field are investigated under the conditions of carrier excitation (ωL=ω0), red excitation ［ωL=ω０-jν(j=1,2,3)］ and blue excitation ［ωL=ω０+jν(j=1,2,3)］.The time_evolution of the state of the system,the photon_and phonon_state exchange conditions and the corresponding populations of the ion are discussed.The corresponding averages and variances for photon and phonon numbers,as well as the second_order correlation function for the photon and phonon fields etc,have been obtained.
The principle of statistically optimal planar near-field acoustical holography and the sound field separation technique
Authors: Li Wei-Bing  , Chen Jian  , Yu Fei  , Bi Chuan-Xing  , Chen Xin-Zhao  ,   合肥工业大学动态测试中心，合肥  230009
Published: December 2020

Since the sound pressures are measured on the holographic plane with a finite size, there are windowing effects and wraparound errors in the planar near_field acoustical holography (NAH) based on spatial fast Fouries transform (FFT)_based planar NAH). In order to overcome the windowing effects and wraparound errors, statistically optimal planar near_field acoustical holography (SOPNAH) is used. The sound field superposition theory is used to prove the formulas for the SOPNAH. A simple and effective method for choosing the wave number vector is proposed by means of limiting the spatial wavenumber in the kx,ky directions and discretizing the wavenumber space plane demarcated by the maximum and minimum of kx,ky. To overcome the limitation, that sound field on one side of the holographic plane must be free, in the application of the normal SOPNAH, the sound field separation technique with double holographic planes is proposed. Some results of experiment and numerical simulation are presented to demonstrate the validity of the formulas.
Variation of the target absorptance and target temperature distribution before melting in the pulsed laser ablation process
Authors: Zhang Duan-Ming  , Li Li  , Li Zhi-Hua  , Guan Li  , Hou Si-Pu  , Tan Xin-Yu  ,   华中科技大学物理系，武汉  430074
Published: December 2020

We have discussed the effect of the variation of target absorptance on the temperature distribution of the target before melting. The relationship of the target absoptance with time is derived. Based on this relationship and the actual shape of incident energy density which is a Gauss distribution, the relevant heat flow equation is set up. By using the finite difference method, heat flow equation under an appropriate boundary condition is solved. We have obtained the temperature distribution as function of time and location. At the same time, we have also discussed the physical picture of a relevant process in detail. Finally, we have studied the effect of the variation of absorptance and the distribution of incident energy density on the relevant process. The result shows that during the pulsed laser process, the variation of target absorptance has an important effect on the final simulation result. If this variation is neglected, a remarkable difference can be found between theoretical results and experimental data.
Sub-femtosecond passive synchronization of Ti:sapphire lasers
Authors: Tian Jin-Rong  , Wei Zhi-Yi  , Wang Peng  , Zhao Ling-Hui  , Wang Zhao-Hua  , Zhang Jun  , Han Hai-Nian  , Zhang Jie  ,   (1)中国科学院物理研究所光物理重点实验室, 北京  100080; (2)中国科学院物理研究所光物理重点实验室, 北京  100080;中国科学院计量测试高技术联合实验室,北京  100080
Published: December 2020

Two independent femtosecond Ti:sapphire lasers are passively synchronized by an enhanced cross-phase-modulation technique. The synchronization operation is ma intained over 24 h with a timing jitter of 078 fs.
Optimal design of electrooptic modulator of biaxial crystal
Authors: Wu Dan-Dan  , She Wei-Long  ,   中山大学光电材料与技术国家重点实验室,广州  510275
Published: December 2020

The new wave coupling theory of linear electrooptic effect is used to study the thermal property of an electrooptic modulator made from biaxial crystal KTP. We find one direction, along which the output intensity of the modulator is not sensitive to temperature within an angle range of azimuth φ. Furthermore, we achieve an optimal design of the modulator by adjusting the length of the crystal and the direction of the external electric field.
A first principle study on the geometry and the electronic structures of VC(001) relaxed surface
Authors: Zhang Yong-Fan  , Ding Kai-Ning  , Lin Wei  , Li Jun-Qian  ,   (1)福州大学化学系, 福州  350002; (2)福州大学化学系, 福州  350002;中国科学院福建物质结构研究所，结构化学国家重点实验室,  福州  350002
Published: December 2020

By using the first principle method, the geometry and electronic structures of the clean VC(001) surface are investigated. Similar to the TiC(001) surface, the relaxation of the VC(001) surface leads to the C and V atoms on the top layer move outward and inward, respectively. Results of band structure calculation show that the band structures of transition metal (001) surfaces can be well described by the rigid band model. For the VC(001) surface, the surface states are mainly located around 30eV below the Fermi level, and mainly originate from the 2pz orbital of C atom in the top layer. In addition, the surface states derived from the top layer V 3d orbitals are also observed near the Fermi level. Since these states contain significant contributions of those 3d orbitals vertical to the surface (3d２z and 3dxz/dyz), which will play important roles in the surface reactions, it could be expected that the VC(001) surface exhibits different surface reactivity compared with the TiC(001) surface.
Nonlinear absorptions in Au-nanoparticles-precipitated glasses induced by a femtosecond laser
Authors: Qu Shi-Liang  , Zhao Chong-Jun  , Gao Ya-Chen  , Song Ying-Lin  , Liu Shu-Tian  , Qiu Jian-Rong  , Zhu Cong-Shan  ,   (1)哈尔滨工业大学(威海)物理系，威海  264209; (2)哈尔滨工业大学(威海)物理系，威海  264209;中国科学院上海光学精密机械研究所,上海  201800; (3)哈尔滨工业大学应用物理系，哈尔滨  150001; (4)中国科学院上海光学精密机械研究所,上海  201800
Published: December 2020

We have investigated, by using Z-scan technique with ns pulses at 532nm, the nonlinear absorptions of Au-nanoparticles-precipitated glasses obtained by irradiation of focused femtosecond pulses with the help of heat treatment. We observed the saturable absorption behavior in Au-nanoparticles-precipitated glasses.We obtain, by fitting to the experimental results, in the light of the local field effect near the surface plasmon resonance,Imχ(3)m=57×10-7 esu for the imaginary parts of the third-order susceptibilities for Au nanoparticles. The nonlinear response of Au nanoparticles in the glass samples arises mainly from the hot electron contribution.
Lagrangian function and conserved quantity of onedimensional relativistic harmonic oscillator containing a quadratic velocity drag force term
Authors: Lou Zhi-Mei  ,   绍兴文理学院物理系,绍兴  312000
Published: December 2020

In this paper, the differential kinematic equation of onedimensional relativistic harmonic oscillator containing a quadratic velocity drag force term is obtained by using Taylor series expansion. The expressions of Lagrangian function and conserved quantity are obtained based on the differential kinematic equation and the characteristic of the conserved quantity.
Genetic algorithm optimization based proportional-integral-derivative controller for unified chaotic system
Authors: Wang Dong-Feng  ,   华北电力大学自动化系,保定  071003
Published: December 2020

Proportional-integral-derivative (PID) control of unified chaotic system (UCS) was researched. For optimization of PID controller's structure and parameners, a parallel genetic algorithm (PGA) was proposed. In GA evolution process, hybri d decimal system and binary system matrix encoding technique was adopted. Simula tion study results of optimal PID control for UCS show that: 1) UCS can be cont rolled to unstable zero equilibrium point by using only one PI controller. 2) U CS can be controlled to any unstable non-zero equilibrium point by using three PI controllers. 3) The proposed PGA owns global optimization ability, it can av oid premature problem of simple GA. 4) The control system obtained good regulat ing performance and strong robustness.
Application of interference theory in photonic crystals
Authors: Feng Zhi-Fang  , Wang Yi-Quan  , Feng Shuai  , Cheng  Bing-Ying  , Zhang Dao-Zhong  ,   中国科学院物理研究所，北京  100080
Published: December 2020

In this letter the propagation of electromagnetic wave in a round cavity of photonic crystals is analysed both theoretically and experimentally. Frequency sele cted propagation has been realized by changing the parameters of the photonic cr ystal. We have computed theoretically the transmission spectrum. In the experiment, we have also measured the transmission spectrum.
Studies on C22 radical by optical emission spectroscopy in an induc tively-coupled CF44/CH44 plasma
Authors: Huang Song  , Xin Yu  , NingZhao-Yuan  ,   苏州大学物理科学与技术学院、薄膜材料江苏省重点实验室,苏州  215006
Published: December 2020

In this paper, actinometric optical emission spectroscopy (AOES) is used to inve stigate the discharge of CF44 and CH44 mixtures. Relat ive concentratio ns of radicals in an inductively_coupled plasma are determined as functions of rf input power, pressure and the gas flow ratio R (R=［CH44］/{［CH 44］+［CF44］}). It is found that CF，CF22 ，CH，H and F radicals exis t in the CF44/CH44 plasma as well as C22 radical. The relative co ncentration of C22 increases with increasing power, and shows a rev erse “U” shape tendency with increasing pressure. As R increases, the variati on of the relative concentration of C22 is not monotonical. It reac hes a ma ximum value when Ｒ＝75%, then decreases followed by almost no change with the further increase of R. Based on these results, it is concluded that gas_pha se reaction from the reaction of CF and CH （ＣＦ＋ＣＨ→Ｃ２2＋ＨＦ ） contribu tes to the production of C22 radical. At the same time, activation reaction model of radical collision is suggested. Result of simulation agrees well with that of experiment.
Electronic and magnetic properties of 3d transition-metal-doped Ⅱ-Ⅳ-Ⅴ22 chalcopyrite semiconductor
Authors: Zeng Yong-Zhi  , Huang Mei-Chun  ,   厦门大学物理系,厦门  361005
Published: December 2020

A systematic study based on ab initio calculation within local spin density appr oximation is carried out for material design of Ⅱ-Ⅳ-Ⅴ22 chal copyrite semiconductor (CdGeP22 and ZnGeP22) doped with 3d-TM (TM= V, Cr, Mn, Fe, Co and Ni). It is found that the ferromagnetic (FM) state will be realized in V and Cr doped CdGeP22 and ZnGeP22; for Mn, Fe and Co doped ones, the antiferromagnetic (AFM) states are more stable than FM states; whereas dope d with Ni, the dilute magnetic semiconductor (DMS) shows unstable ferromagnetism . It is suggested that Ⅰ-Ⅳ-Ⅴ22 chalcopyrite semiconductor doped with Cr is a candidate for high Curie temperature (TCC) DMS. When th e t2g2g states of TM are partially occupied, the DMS doped with TMs shows a stable FM state, whereas when the t2g2g states of TMs are fully occupied or empty, the DMS with the TM shows AFM state. In order to elucid ate the underlying mechanism of the ferromagnetism in DMS, the magnetism in (C d,Mn)GeP22 and (Cd,Mn)GeP22 under the carrier (elect ron or hole) doping treatment is investigated. It is found that it is crucial to realize the carrier-induced ferromagnetism, indopendent of whethe r the doped carrier has itinerant TM-3d character or not.
Effect of magnetic field on the transport properties of heavy electron compounds CeCu6-x6-xCdxx
Authors: Jiang Li-Xia  , Meng Ji-Bao  , Chen Zhao-Jia  , Luo Jian-Lin  ,   (1)北京联合大学基础部,北京  100101; (2)中国科学院物理研究所,北京  100080
Published: December 2020

We report the low-temperature resistance under a magnetic field (μ０0H=0, 5 and 10T) within the temperature range from 18 to 300K and low temp erature (T=19 and 15K) magneto_resistance (μ00H=0—10T) of hea vy electron compounds CeCu6-x6-xCdxx(x=010，015 ，020，0 30，050). The experiments show that the Tmaxmax（correspondin g to the max imal resistance）of all samples are not observed over 18K under zero magneti c field. When a magnetic field is applied, the Tmaxmax increases with inc reasing magnetic field and doping content x. Meanwhile, the magneto_resista nces are all negative at 19K and the positive magneto_resistance of part of samples is observed at 15K. This phenomenon can be explained by Kondo scatteri ng and coherent scattering.
The working stability of the reflection-modemagneto-optical multilayer film i solators
Authors: Wen Xiao-Wen  , Li Guo-Jun  , Qiu Gao-Xin  , Li Yong-Ping  , Ding Lei  , Sui Zhan  ,   (1)中国工程物理研究院激光核聚变研究所,绵阳  621900; (2)中国科学技术大学物理系,合肥  230026
Published: December 2020

Compared with massive magneto-optical (MO) crystals, the one-dimensional MO photonic crystals, which are composed of magneto-optical and dielectric films per iodically or quasi-periodically, have a notable enhancement in MO effects, so t hey are very useful for fabricating micro-size MO isolators with only tens of m icrons in thickness. Our theoretical calculations are based on a transfer matri x method that is suitable to solve the problems of the propagation of polarized light in anisotropic media at an oblique incident angle. Using this method, we h ave discussed the working stability of two particular types of “sandwiched" ref lection-mode MO multilayer film isolators with the change of incident angle and film thickness at λ=1053μm. It is revealed that the structure with a thicker central MO medium has the advantages of better working stability and les s necessary layers.
Adaptive noise cancellation for SQUID-based magnetocardiogram
Authors: Liu Xin-Yuan  , Xie Bai-Qing  , Dai Yuan-Dong  , Wang Fu-Ren  , Li Zhuang-Zhi  , Ma Ping  , Xie Fei-Xiang  , Yang Tao  , Nie Rui-Juan  ,   (1)北京大学物理学院,人工微结构和介观物理国家重点实验室,北京  100871; (2)北京大学信息科学技术学院,北京  100871
Published: December 2020

This paper presents the implementation about adaptive noise cancellation by prov iding several kinds of algorithms with the objective of removing the 50Hz noi se from magnetocardiogram(MCG) based on SQUID. The computer simulation results o f the algorithms are given for comparison. The result shows that 50Hz power li ne noise in MCG taken by SQUID has been fairly well eliminated by an adaptive no ise canceller.
Analytical solution of electric potential produced by a direct current point sou rce located in a multilayered spherical volume conductor
Authors: Xiao Chun-Yan  , Lei Yin-Zhao  ,   北京航空航天大学自动化与电气工程学院,北京  100083
Published: December 2020

A general analytical solution is derived for an electric potential produced by a direct current point source located at any position in a multilayered spher ical volume conductor. Starting from Poisson's equation, the electric potential whose coefficients are rapidly got in the form of matrix expressions is obtained according to the boundary conditions. Simulation for a four-layered spherical volume conductor denoting the scalp, skull, cerebrospinal fluid and brain tissue proves that electric potential in this paper converges more rapidly in the whol e region than that expressed only in spherical harmonics expansion form, and ite rative times decrease. Electric potential contour and current streamline figur es show that it is important to consider the effect of the low conductivity of s kull on electric potential and current flow. The distribution of electric potent ial on the surface of sphere is discussed, which will be useful in electroenceph alography inverse problems, and also in analyzing and interpreting the electric potential measurement.
Simulation and theoretical analysis on detection of the frequency of weak harmonic signals based on a special chaotic system
Authors: Li Yue  , Yang Bao-Jun  , Lin Hong-Bo  , Liu Xiao-Hua  ,   (1)吉林大学地球物理系，长春  130026; (2)吉林大学信息工程系，长春  130012
Published: December 2020

In order to study a kind of chaotic system which is based on the special Duffing-Homes equation, and use it to detect the unknown frequency of weak harmonious s ignals, we prove the existence of the periodic solution and the exclusivism of the solution, carry out simulation experiments to detect harmonious frequency us ing the periodic trajectory of a stable phase state.We also compute the detectio n error |Δω|,when the damping ratio (α) changes and the frequency changes fro m 1Hz to 200Hz. The results show that we have to choose the value of α correspo nding to the different range of frequency by simulation experiments.
Experimental diagnoses of plasma electron density by interferometry using an x-ray laser as probe
Authors: Wang Chen  , Wang Wei  , Sun Jin-Ren  , Fang Zhi-Heng  , Wu Jiang  , Fu Si-Zu  , Ma Wei-Xin  , Gu Yuan  , Wang Shi-Ji  , Zhang Guo-Ping  , Zheng Wu-Di  , Zhang Tan-Xin  , Peng Hui-Min  , Shao Ping  , Yi Kui  , Lin Zun-Qi  , Wang Zhan-Shan  , Wang Hong-Chang  , Zhou Bin  , Chen Ling-Yan  ,   (1)北京应用物理与计算数学研究所，北京8009信箱，北京  100088; (2)上海光学精密机械研究所，上海800-211信箱，上海  201800; (3)上海激光等离子体研究所，上海800-229信箱，上海  201800; (4)上海市同济大学物理系，上海  200092
Published: December 2020

The interferometry with an x-ray laser as probe is an important tool of diagnosing the electron density of a high temperature and dense plasma. A successful experiment of diagnosing the density of a CH plasma was demonstrated by using a Ni-like Ag x-ray laser as a probe and a Mach-Zehnder interferometer as instrument under the ShenguangII laser facility. The legible interferogram indicating the information of electron density was obtained.
Scattering of fundamental Gaussian beam from on-axis cluster spheres
Authors: Bai Lu  , Wu Zhen-Sen  , Chen  Hui  , Guo Li-Xin  ,   西安电子科技大学理学院，西安  710071
Published: December 2020

Based on the generalized Lorenz_Mie theory(GLMT),the incident fundamental Gaussi an beam is expanded in terms of the vector spherical harmonics. The interaction of Gaussian beam with a cluster composed of spheres located on the propagation a xis is analyzed. The numerical results are discussed and compared with those obt ained in the plane wave incident case.
A study of acoustic levitation process based on laser holographic interferometry
Authors: Zhang Lin  , Li En-Pu  , Feng Wei  , Hong Zhen-Yu  , Xie Wen-Jun  , Ma Yang-Hua  ,   西北工业大学理学院应用物理系，西安  710072
Published: December 2020

By using double-exposed holographic interferometry, the distribution of sound pr essure in the acoustic levitation field is analyzed. The holograms under differe nt conditions are obtained and compared with each other. It is shown that the me asured holograms are consistent with the theoretical ones, and the intensity dis tributions along their central axis are identical. Compared with other methods, double-exposed holographic interferometry has the merits of non-contact, non-int rusive and whole-field measurement; and it provides a more convenient and more i ntuitionistic approach to realize acoustic field and guarantees the optimization of acoustic levitation system.
Quasi-phase-matched second-harmonic-generation in bulk periodically poled LiNbO3 and optimal design
Authors: Chen Yun-Lin  , Yuan Jian-Wei  , Yan Wei-Guo  , Zhou Bin-Bin  , Luo Yong-Feng  , Guo Juan  ,   (1)南开大学物理科学学院,天津  300071; (2)南开大学物理科学学院,天津  300071;山东大学晶体材料国家重点实验室，济南  250100
Published: December 2020

Quasi-phase-matched second harmonic generation(SHG) in bulk periodically poled L iNbO3(PPLN) was studied , the coupled-wave equations for quasi-phase- matched S HG was accurately resolved, and the formula for calculating SHG conversion effic iency under focusing Gauss beams was given. The relations between focusing beams  waist and crystal length were analyzed. Furthermore, the SHG cavity was opti mized to obtain the maximum conversion efficiency.
Optimum phase matching for SHG in biaxial crystals
Authors: Ma Yang-Hua  , Zhao Jian-Lin  , Wang Wen-Li  , Huang Wei-Dong  ,   (1)西北工业大学理学院光信息科学与技术研究所，西安  710072; (2)西北工业大学凝固技术国家重点实验室，西安  710072
Published: December 2020

The phase matching for second harmonic generation(SHG) in biaxial nonlinear-optical crystals is discussed and the accurate calculation of the corresponding effective nonlinear coefficients is presented, based on which the optimum phase matching can be determined. As an example, numerical treatment of phase matching and the corresponding effective nonlinear coefficients for SHG at fundamental wavelengths of 1.064μm and 0.808μm in the organic nonlinear-optical crystal benzophenone is performed, and accordingly the optimum phase matchings are found.
Frictional property of wetting contact line and Wenzel’s behavior of solid surface tension
Authors: Cao Xiao-Ping  , Jiang Yi-Min  ,   (1)中南大学物理科学与技术学院，长沙  410083; (2)中南大学物理科学与技术学院，长沙  410083;蒂宾根大学理论物理研究所，蒂宾根  72076德国
Published: December 2020

Based on the static-friction model for solid-liquid-vapor contact line suggested by Adam and Jessop，one can calculate surface-tension coefficient of solids from the data of wetting angles, but the results depend on the friction condition adopted. Using the data reported on stainless steel and polypropylene samples as examples, we have compared the surface-tension coefficients given by the Mises yield condition and Amonton's friction law. It is found that only the latter pos sesses always the Wenzel behavior which claims an increase of surface-tension co efficient with surface roughness, as well as total wetting condition, namely rec eding angle vanishes when the difference of solid-liquid and solid-vapor coeffic ients equals that of liquid-vapor. This shows that the Amonton's law seems to be more reasonable for describing the static friction of contact line.
The self-consistent theoretical study of the effect of surface plasmon and polariton on electronic transport Ⅱ——The calculation and analysis of molecular orbital field in MIM system
Authors: Miao Jiang-Ping  , Wu Zong-Han  , Sun Cheng-Xiu  , Sun Yue-Ming  ,   (1)东南大学电子工程系，南京  210096; (2)东南大学电子工程系，南京  210096;东南大学物理系，南京  210096; (3)东南大学化工系，南京  210096; (4)东南大学物理系，南京  210096
Published: December 2020

Adopting the self-consistent method to calculate the coefficient of molecular orbital (MO) field in a metal/insulator/metal (MIM) system under the effect of a static electric field, we obtain the result that the distribution of the MO coe fficient appears in the form of sine function. With increasing electric field, t he energy band shifts to the deep energy area, and the energy peaks separate fro m each other more evidently, and the overlap of hybrid states between the 3dm group atomic orbits constructing the current pass increases, which im prove s the power of charge transportation. This work provides the method for research ing the effect of surface plasmon and polariton on charge transportation.
Rectifying characteristics of La0.9Sr0.1MnO3/Si p-n diodes
Authors: Liu Li-Feng  , Lü Hui-Bin  , Dai Shou-Yu  , Chen Zheng-Hao  ,   中国科学院物理研究所，北京凝聚态物理国家实验室，北京  100080
Published: December 2020

Simple p_n diodes have been fabricated by direct growth of La0.9Sr0.1MnO3 thin films on n_type silicon substrates.These junctio ns exhibit good rectifying characteristic in a wide temperature range from 50 to 280K.Large magnetoresistance up to 70% was observed in a low field of 3×10-2T in th ese junctions.The junction magnetoresistance depends on bias and temperature.
Microstructure, dielectric and piezoelectric properties of mixed-layered Bi7Ti4NbO21 ferroelectric ceramics
Authors: Zhang Li-Na  , Zhao Su-Chuan  , Zheng Liao-Ying  , Li Guo-Rong  , Yin Qing-Rui  ,   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
Published: December 2020

Bi7Ti4NbO21, Bi4Ti3O 12 and Nb-doped Bi4Ti3O12 la yer-structure ferroelectric ceramics were prepared. Microstructure, dielectric and piezoelectric properties of Bi7Ti4NbO21 were investigated by comparing with the electrical properties of Bi4Ti3O12 and Nb-doped Bi4Ti3O12. High resolution transmission electron microsco py result of Bi7Ti4NbO21 showed an intergrowth structure of perovskite -like(Bi2Ti3O10)2-, (BiTiNbO7)2- layers and (Bi 2O2)2+ layer along c direction. Two dielectric anomalies of Bi7Ti4NbO 21 occurred at 668 and 845℃. The material underwent a ferroelectric-ferroelectric and a ferroe lctric-paraelectric phase transition at the low and high temperatures. They were attributed to the microstructure transition of (Bi2Ti3O10)2- an d (BiTiNbO7)2- perovskite layers, respectively. During the depolarizat ion, the piezoelectric coefficient d33 of Bi7Ti 4NbO21 decrease d by 10% of its initial value over 200℃. The reason was that the directional ar rangement of defect dipoles created by some vacancies was damaged. The results o f depolarization experiment and thermally stimulated current measurement indicat ed that the piezoelectric properties of Bi7Ti4NbO 21 came from the polarization of intrinsic dipoles and defect dipoles.
Interface-energy calculation for Ag/Ni twist boundaries with MAEAM
Authors: Zhang Jian-Min  , Xin Hong  , Wei Xiu-Mei  ,   陕西师范大学物理学与信息技术学院，西安  710062
Published: December 2020

Interface-energies of Ag(111)//Ni(001) and Ag(001)//Ni(111) twist boundaries have been calculated with the modified afom-embeded analysis method(MAEAM). The results show that, for Ag(111)//Ni(001) twist boundary, the lowest energy is corresponding to the twist angle θ=0° (or 30°), this preferable twist angle orientation is consistent with the experimental results reported in the literature. For Ag(001)//Ni(111) twist boundary, similarly, the lowest energy is corresponding to θ=0° (or 30°). From interface energy minimization, the preferable twist angle is 0° (or 30°) for Ag(001)//Ni(111) twist boundary too.
Effect of multiwalled carbon nanotubes on the thermoelectric properties of p-type Ba0.3FeCo3Sb12 compounds
Authors: Luo Pai-Feng  , Tang Xin-Feng  , Xiong Cong  , Zhang Qing-Jie  ,   武汉理工大学材料复合新技术国家重点实验室,武汉  430070
Published: December 2020

The p_type Ba_filled Ba0.3FeCo3Sb１2 skutterudite compounds were synthesized using a two_step solid_state reaction method, and the Ba0.3FeCo3 Sb１2/multiwalle carbon nanotubes composites were prepared by spark plasma sintering (SPS). The structure of Ba0.3FeCo3Sb１2/multi walled carbon nanotube composites and effect of multiwalled carbon nanotubes on the thermoelectric properties of p_type Ba0.3FeCo3Sb１2 compounds w ere investigated. The dispersed distribution of multiwalled carbon nanotubes in the Ba0.3Fe Co3Sb１2 compounds was observed by SEM. With increasing content of multiwal led carbon nanotubes, the electrical conductivity of the Ba0.3FeCo 3Sb１2 compounds decreased, Seebeck coefficient reduced slightly and the lattice thermal conductivity decreased significantly. The minimum of lattice thermal conductivity was obtained when the content of carbon nanotubes was 5%. When the content of carbon nanotubes was 3%, the maximal ZT value of 078 was obtained for Ba0.3FeCo3Sb１2/multiwalled carbon nanot ube composites at 850K.
Routh equation of nonholonomic dynamical systems: from Chetaev condition to Euler condition
Authors: Shen Hui-Chuan  ,   中国科学技术大学天文与应用物理系统计力学中心，合肥  230026
Published: December 2020

The Routh equation of a nonholonomic system with a nonlinear constraint equation that is expandable to MacLaurin progression on generalized velocity, can be obtained by Lagrangian multiplier method and d'Alembert principle in an ideal constraint condition. Chetaev condition is valid in linear nonholonomic system only, and is eguivalent to Vacco condition. The so-called “Euler condition" can unite Chetaev condition and Vacco condition, can unite d'Alembert principle and Hamilton principle, and can resolve all existing problems in nonlinear nonholonomic system.
A new method based on the construction of hypothetical symmetrical networks for fixture calibration in network analyzers
Authors: Liu Chao  , Zhang Shang-Jian  , Xie Liang  , Zhu  Ning-Hua  ,   中国科学院半导体研究所集成光电子学国家重点实验室，北京  100083
Published: December 2020

At least three known standards are normally required for the full two-port test fixture calibration in vector network analyzers (VNA). In this paper, a calibration procedure using only one standard, based on establishing two hypothetical symmetrical fixtures using triple-through method, is shown. The results using th e calibrating method to subtract the influence of fixtures are in accord with th e directly measured data of the device-under-test (DUT) without the fixtures ver y well, which shows that the proposed method is very simple and accurate.
Longitudinal self-modulation of an intense relativistic electron beam in a two-cavity system
Authors: Hu Min  , Zhu Da-Jun  , Liu Sheng-Gang  ,   电子科技大学物理电子学院,成都  610054
Published: December 2020

Self_modulation may appear on an intense relativistic electron beam(IREB) trave rsing a two_cavity klystron system. It is caused by the intense relativistic eff ect. RF output can be obtained without RF input. Based on this mechanism, a new type of high_power microwave source is suggested. The oscillation condition of t he intense relativistic election beam, traverse mechanism and PIC simulation are presented. After optimization design, a 800MW output peak microwave power was o bserved at a frequency of 099GHz, while an electron beam of voltage 500kV, cur rent 4kA is injected. The efficiency is about 40%.
Studies on two-photon absorption cross-sections of 1，4-dimethoxy-2，5-divinyl-benzene derivatives
Authors: Zhao Ke  , Sun Yuan-Hong  , Wang Chuan-Kui  , Luo Yi  , Zhang Xian  , Yu Xiao-Qiang  , Jiang Min-Hua  ,   (1)Laboratory of Theoretical Chemistry,Royal Institute of Technology,SCFAB,S_10691 Stockholm,Sweden; (2)山东大学晶体材料国家重点实验室，济南  250100，中国; (3)山东师范大学物理与电子科学学院, 济南  250014，中国; (4)山东师范大学物理与电子科学学院, 济南  250014，中国;Laboratory of Theoretical Chemistry,Royal Institute of Technology,SCFAB,S_10691 Stockholm,Sweden
Published: December 2020

The one_photon and two_photon absorption properties of a series of 1，4_di methoxy_2，5_divinyl_benzene derivatives are investigated by use of the analytic response theory at HF level. The one_photon and two_photon fluorescence spectra of E，E_2_5_Bis［4′_(N,N_di_n_butylamino) styryl］_1，4_dimenthoxybenzene are measured. The numerical results show that these molecules have strong two_photon absorption cross sections. In the visible light region，the maximal one_photon absorption strengths of the molecules occur in the first excited state. Furtherm ore，the maximal two_photon absorption cross sections of the D_π_A typed molecu les still appear in the first state，　but for D_π_D typed molecules the second excited state has the maximal two_photon absorption cross_section.　The optical properties of the molecules are closely related to the electric property of the donor and acceptor.　The symmetrically substituted molecules can not be determi ned to have a larger two_photon absorption cross section than the asyrnmetricall y substituted molecules for such a kind of π_center.　The charge_transfer proce ss for the charge_transfer states is displayed，and then the mechanism of photop olymerization is discussed qualitatively.
Dependence of silica sol properties on synthesis situation studied by SAXS
Authors: Xu Yao  , Wu Dong  , Sun Yu-Han  , Li Zhi-Hong  , Dong Bao-Zhong  , Wu Zhong-Hua  ,   (1)中国科学院高能物理研究所，同步辐射国家实验室,北京  100039; (2)中国科学院山西煤炭化学研究所，煤转化国家重点实验室,太原  030001
Published: December 2020

The properties of silica sol, such as the interface characteristics and microstr ucture, were comparatively studied by small angle x-ray scattering (SAXS) assis ted by dynamic light scattering. Four synthesis routes were adopted to relate th e properties of silica sol with the synthesis situation. Very big difference of SAXS results was found between the base-catalyzed and the acid-catalyzed silic a sols with ethanol used as solvent. Under the acid-catalysis of low molecule-w eight organic acid, not only were polysiloxane macromolecules obtained, particle suspension of silica was also produced with complicated inner structures of pa rticles. With ethanol or water as solvent, it was found that the silica particl e would become more irregular in morphology with more polarity of solvent. The formation of Si-O tetrahedron was more difficult in the acidolysis of tetraetho xysilane by formic acid than in the other hydrolysis routes. An interesting co- existing of positive deviation and negative deviation from Porod’s law was foun d in the silica sol with water solvent, and a detailed explanation has been giv en.Many nano-scaled structural difference among these different synthesis situa tions were revealed, which was difficult to be recognized by the experimental m ethods other than SAXS.
Effect of magnetic field on the interfacial microstructure between molten aluminium and solid iron
Authors: Han Yi  , Ban Chun-Yan  , Ba Qi-Xian  , Wang Shu-Han  , Cui Jian-Zhong  ,   东北大学材料电磁过程研究教育部重点实验室, 沈阳  110004
Published: December 2020

The effects of DC and AC magnetic fields on the interfacial microstructure betw een molten aluminium and solid iron were studied, and the intermetallics formed in the diffusion layers were also investigated by means of metallography, electr on microprobe (EPM) and x-ray diffraction (XRD). Results showed that the diffusi on layer in solid iron under DC and AC magnetic fields was thinner than that w ithout magnetic field, and the interface became irregular under AC magnetic fiel d. In the direction perpendicular to the magnetic field, DC magnetic field dampe d the diffusion between aluminium and iron; on the contrary, under AC magnetic field diffusion was enhanced; the diffusion layer in solid iron was mainly comp osed of Fe2Al5 and FeAl3 without magnetic field , while there was only Fe2Al5 under DC magnetic field, and Fe2Al5 and Fe4Al13 under AC magn etic field.
Statistical entropy of Kerr-Newman-de Sitter black hole
Authors: Li Gu-Qiang  ,   湛江师范学院信息科技学院，广东湛江  524048
Published: December 2020

The partition functions of bosonic and fermionic field in Kerr-Newman-de Sitter black hole are derived directly by using the method of quantum statistics. Th en the entropy of the Kerr-Newman-de Sitter black hole is calculated by using the improved brick-wall method with the membrane model.
Ordered structures and self-organized phenomena in Au films deposited on silicone oil surfaces
Authors: Xia A-Gen  , Yang Bo  , Jin Jin-Sheng  , Zhang Yi-Wen  , Tang Fan  , Ye Gao-Xiang  ,   浙江大学物理系,杭州  310027
Published: December 2020

An optical microscopy study of ordered structures and self-organized phenomena in a continuous gold film system deposited on silicone oil surface is presented. Band-shaped ordered patterns, namely bands, are formed after deposition under certain condition. The bands are composed of a large number of parallel key-shaped domains with different width but nearly uniform length. Further experiments show that the ordered patterns result from compressive stress in films. We also study the formation mechanism of internal stress in nearly free sustained films.
A study of a main-road traffic flow model with turning-probability under open-bound condition
Authors: Huang Ping-Hua  , Tan Hui-Li  , Kong Ling-Jiang  , Liu Mu-Ren  ,   (1)广西工学院信息与计算科学系,柳州  545005; (2)广西师范大学物理与信息工程学院,桂林  541004
Published: December 2020

A main-road cellular automata traffic flow model with turning-probability in t erms of rules of the improved Nagel-Schreckenberg is presented under the open b oundary condition. The different characteristics of the phase transition led to by the turning probability and the open boundary condition are studied for the improvement on the traffic flow.
The phase diagram of Hubbard model with alternating chemical potentials
Authors: Xu Jing  , Wang Zhi-Guo  , Chen Yu-Guang  , Shi Yun-Long  , Chen Hong  ,   (1)同济大学物理系,上海  200092; (2)雁北师范学院物理系,大同  037000; (3)雁北师范学院物理系,大同  037000;同济大学物理系,上海  200092;中国科学院上海技术物理研究所，上海  200083
Published: December 2020

We have investigated the ground-state phase diagram of the one-dimensional Hubbard model with alternating chemical potentials at half-filling by bosonization technique and the Gaussian wave functional method. We calculate variations of the charge density wave (CDW) and the spin density wave (SDW) gaps, ad well as their classical trajectory c,s with increasing on-site Coulomb repoulsion potential. For the fixed potential, it is found that the transition from the band insulator (BI) to the spontaneously dimerized insulator (SDI) is of the Ising type, at which charge gap vanishes, while the transition from SDI to the Mott insulator (MI) is of the KT type.
Ab initio study of the effects of Mg doping on electronic structure of Li(Co , Al)O2
Authors: Xu Xiao-Guang  , Wang Chun-Zhong  , Liu Wei  , Meng Xing  , Sun Yuan  , Chen Gang  ,   吉林大学麦克德尔米德实验室,吉林大学材料科学与工程学院，汽车材料教育部重点实验室,长春  130023
Published: December 2020

Electronic structures of Li(Co, Al)O2 and Mg-doped Li(Co, Al)O2 were studied theoretically via ab initio calculation based on density-functional theory. Studies of band structures and density of states show that hole states appear in the valence bands of the Mg-doped material as well as an increase in bandwidth, which are in charge of the increase in the observed electronic conductivity. It was found by analysis of Co3d density of states that the divalence Mg doping induces a higher cobalt valence state between Co3+ and Co4+ in Li(Co, Al, Mg)O2, which is in good agreement with experimental results. Using the band theory, we have calculated the average valence states of Co and O.
Study on gain fluence curve of a laser pulse amplifier
Authors: Liu Ren-Hong  , Cai Xi-Jie  , Yang Lin  , Zhang Zhi-Xiang  , Bi Ji-Jun  ,   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，上海  201800
Published: December 2020

This paper discusses a method of characterizing the gain of the laser pulse amplifier using its gain fluence curves,and studies gain fluence curves of a single amplifier.These help us to understand the characteristics of the amplifier and provide a powerful tool for the investigation of the power balance.
A kinetics model for metastable-metastable transition laser in Sr atom vapor
Authors: Chen Gang  , Feng Jian  , Pan Bai-Liang  , Yao Zhi-Xin  ,   (1)杭州工人业余大学，杭州  310003; (2)浙江大学物理系，杭州  310027
Published: December 2020

A self-consistent physical model has been developed to simulate the kinetics in a high-repetition frequency, discharge-excited Sr atom metastable-metastable transition laser. The main pumping mechanism for each upper laser level has bee n clarified: the upper level of 301μm is pumped mainly by the spontaneous and stimulated emissions from the higher levels in early discharge pulses, while th e upper levels of the other 3 laser lines are chiefly populated through the reco mbination between the univalent Sr ions and electrons in the afterglow, and the collision mixing between neutral He and Sr atoms in compound triplet. The quant itative results predicted by the model are found to be in good agreement with th e previous experimental results. Furthermore, the temporal behavior of each lase r pulse is explained successfully by the simulation results.
Photoinduced birefringence in an azo-dye-doped polymer
Authors: Qi Sheng-Wen  , Yang Xiu-Qin  , Chen Kuan  , Zhang Chun-Ping  , Zhang Lian-Shun  , Wang Xin-Yu  , Xu Tang  , Liu Yong-Liang  , Zhang Guang-Yin  ,   (1)德州学院物理系，德州  253023;南开大学物理学院光子学中心，天津  300071; (2)南开大学物理学院光子学中心，天津  300071
Published: December 2020

Under varying intensities and polarization of the exciting light, the photoinduced birefringence of azo dye polymer film placed between a pair of orthogonal po larizers is studied by measuring the transmitted intensity. It is concluded that the saturation and stable values of the transmitted intensity are all proportio nal to the intensity of the exciting light. Both values are also related to the polarization direction of the exciting light, and when the angle θ between the polarization directions of the probe intensity and the exciting light is lag er than 10°, the saturation and stable values of the transmitted light are all proportional to sin22θ. In addition, the differences in birefringenc es of the sample were measured accurately by using a compensator and 1.11×10-3 (before excitated) and 3.57×10-3 (after excitated) are obtaine d.
Anatase TiO2 and red-shift introduced by doping with Fe:pseudopotential calculations and ultraviolet spectroscropy
Authors: Zhang Yong  , Tang Chao-Qun  , Dai Jun  ,   华中科技大学物理系, 武汉  430074
Published: December 2020

The crystal structure and electronic band structure of undoped and Fe-doped anatase TiO2 have been investigated by using the plane-wave ultrasoft pseudopotential method in the generalized gradient approximation (GGA). The calculation shows that Fe-doping introduces a localized level and narrowing of band gap in TiO2. The t2g state of the dopant plays a significant role in red-shift of spectrum. The previous prediction is confirmed by our experiment.
Experimental investigation of insensitive explosive C6H6N6O6 by small angle x-ray scattering technique
Authors: Xia Qing-Zhong  , Chen Bo  , Zeng Gui-Yu  , Luo Sun-Huo  , Dong Hai-Shan  , Rong Li-Xia  , Dong Bao-Zhong  ,   (1)中国工程物理研究院核物理与化学研究所，绵阳  621900; (2)中国工程物理研究院化工材料研究所，绵阳  621900; (3)中国科学院高能物理研究所，北京  100039
Published: December 2020

Synchrotron radiation small-angle x-ray scattering (SAXS) technique was employed to investigate the pores in the insensitive high explosive C6H 6N6O6(TA TB) manufactured by different methods. The microstructure parameters of the por es such as diameter distribution, fractal character, Porod constant, interface parameter and so on were obtained from SAXS results. Analyses of variations of the microstructure parameters were also made. It is shown that there is an obvio us microstructure feature for each TATB sample.
Studies on dynamical behavior in reaction limited aggregation model
Authors: Tang Jun  , Yang Xian-Qing  , Qiu Kang  ,   中国矿业大学理学院,徐州  221008
Published: December 2020

Based on reaction limited aggregation model, we have investigated the dynamical process of film epitaxial growth in the presence of surfactant. The results ind icate that there are differences between the growth processes of fractal island and compact island. The growth exponents of fractal islands are greater than 1, which that of compact islands are less than 1. On the other hand, “dead" atom d ensity increases linearly with the coverage in the process of the fractal island growth, but the relations between the density and the coverage are nonlinear in the compact island situation.
High-efficiency red-phosphorescent 6CPt electroluminescence
Authors: Xie Yu-Qing  , Guo Jian-Hua  , Peng Jun-Biao  , Cao Yong  , Wang Yue  ,   (1)华南理工大学高分子光电材料与器件研究所，广州  510640; (2)吉林大学超分子结构与材料教育部重点实验室，长春  130000
Published: December 2020

High-efficiency red polymer phosphorescent light-emitting diodes(PLEDs) have been fabricated based on czrbazole-substituted porphyrin platinum(6CPt)complex and PBD-doped PFO(poss). The best external quantum efficiency of 5.68% has been achieved. The effect of PBD on the device performance was analyzed. We found that PBD improves the energy transfer of excitons from host PFO to guest triplet complex 6CPt.