bluuebunny/crossref_metadata_2025 huggingface dataset:
A study on photoluminescence characterization of high-quality nanocrystalline ZnO thin films
Authors: Zhang Xi-Tian  , Xiao Zhi-Yan  , Zhang Wei-Li  , Gao Hong  , Wang Yu-Xi  , Liu Yi-Chun  , Zhang Ji-Ying  , Xu Wu  ,   (1)哈尔滨师范大学物理系，哈尔滨  150080; (2)哈尔滨师范大学物理系，哈尔滨  150080;中国科学院激发态物理开放研究实验室，中国科学院长春光学精密机械与物理研究所，长春  130021; (3)中国科学院激发态物理开放研究实验室，中国科学院长春光学精密机械与物理研究所，长春  130021
Published: December 2020

In this paper, we report the photoluminescence from high-quality nanocrystalline ZnO thin films. The high-quality nanocrystalline ZnO thin films are prepared by thermal oxidation of ZnS films at 800℃, which are deposited by low-pressure metal-organic chemical vapor deposition technique. X-ray diffraction indicated that the nanocrystalline ZnO thin films have a polycrystalline hexagonal wurtzite structure. A strong ultraviolet emission peak at 3.26 eV was observed and the deep-level emission band was barely observable at room temperature. The strength (ΓLO) of the exciton-longitudinal-optical (LO)-phonon coupling is deduced from the temperature dependence of the full width at half maximum of the fundamental excitonic peak. ΓLO is reduced greatly due to the quantum confinement effect.
Investigation of influences of concentration of Mn and Cu dopants on the decay process of photogenerated charge carriers in the ZnS:Mn,Cu luminescence materials
Authors: Dong Guo-Yi  , Li Xiao-Wei  , Wei Zhi-Ren  , Yang Shao-Peng  , Han Li  , Fu Guang-Sheng  ,   河北大学物理科学与技术学院,保定  071002
Published: December 2020

The decay process of photogenerated charge carriers of ZnS:Mn,Cu luminescence materials after excitation with a short-pulse laser has been investingated in this paper by using the microwave absorption dielectric spectrum detection technique. It was found that the concentration of the Cu and Mn dopants has a great influence on the lifetime of electrons in the conduction band. The lifetime of electrons in the conduction band decreases obviously with increasing concentration of the Cu and Mn dopants. The effect of the concentration of Cu and Mn dopants on the luminescence intensity was also investigated.
The occupying activities of helium in ball-milled hydrogen-storage alloys
Authors: Liu Shi  , Zheng Hua  , Zhao Yue  , Xiong Liang-Yue  , Wang Long-Bao  , Yang Xun  ,   (1)中国工程物理研究院，绵阳  621900; (2)中国科学院金属研究所，沈阳  110016
Published: December 2020

Through the measurements of positron lifetime and analysis of structure, the properties of helium in the ball-milled LaNi4.75Al0.25 and Zr50Co50 alloys were investigated. It was found that the amount of the injected helium increases with increasing helium pressure. It is comparatively easier for helium to enter the LaNi4.75Al0.25 alloy. The difference of the positron lifetime parameters between the above two specimens shows that the properties of the injected helium are different. For Zr50Co50, helium occupies the intersection of two or three crystallite interfaces and/or cluster of vacancies at grain boundaries or groups of vacancies firstly. With increasing pressure of the helium atmosphere, a small amount of helium enters the free volume of single vacancies, and thus vacancy-helium compounds form. For LaNi4.75Al0.25, helium enters the free volume of single vacancies and vacancy-helium compounds form.
A study on spatial light modulator of bacteriorhodopsin film
Authors: Yang Wen-Zheng  , Yang Qing  , Chen Feng  , Feng Xiao-Qiang  , Hou Xun  ,   (1)中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室,西安  710068; (2)中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室,西安  710068;西安交通大学电子科学与技术系，西安  710049
Published: December 2020

An optically addressed spatial light modulator (OA-SLM) is presented by using the excellent nonlinear-optical characteristics of bacteriorhodopsin films (BR films). The BR films have two dominant photoactive states (B state and M state) which have well-separated absorption bands with maxima of B state at 570nm and M state at 412nm. Using the ratio of the shift between the forward （B→M）and backward（M→B）photoreactions, the experimental study on the conversion of coherent-to-incoherent image is realized on BR films. Using the genetic manipulation of the BRD96N film as a sample, the 670nm coherent light as a writing light and the 530nm incoherent light as a readout light, the experimental results for the resolution of ～200 lines/mm and the contrast of about 2.1∶1are achieved.
Scattering states of n-dimensional hydrogen atom
Authors: Chen Chang-Yuan  , Sun Dong-Sheng  , Liu Cheng-Lin  , Lu Fa-Lin  ,   盐城师范学院物理系，盐城  224002
Published: December 2020

Characteristics of the scattering states of an n-dimensional hydrogen atom have been studied. The normalized wave functions of scattering states on “k/2π scale” and the calculation formula of phase shift are presented.The analytical properties of phase shift are discussed, and analytical formulas for calculating bound-continuous transition matrix elements are also given. The relevant results of scattering states for the usual hydrogen atom (n=3) reported in the literature are contained in more general conclusions of this paper as special cases.
Discussion on the calculation of radial matrix elements of three-dimensional isotropic oscillator
Authors: Di Yao-Min  ,   徐州师范大学物理系，徐州  221009
Published: December 2020

A concise general formula of the radial matrix element of the three-dimensional isotropic oscillator is derived using the properties of the general Laguerre polynomials. Some important special cases, such as the average value of the integer power of radial vector, the matrix element of the electric dipole transition and the element of the electric quadrupole transition, are obtained from the general formula.
The reflectivity measurement of the 28.5nm multilayer mirror
Authors: Huang Wen-Zhong  , Li Yin-Jun  , Gu Yu-Qiu  , Zhang Jie  , You Yong-Lu  , CunYu　Shutai  , He Ying-Ling  , Lei An-Le  , Chen Cheng-Lin  , Ma Yue-Yin  , Jin Chun-Sui  ,   (1)中国工程物理研究院激光聚变研究中心，绵阳  621900; (2)中国工程物理研究院激光聚变研究中心，绵阳  621900;中国科学院物理研究所，北京  100080; (3)中国科学院长春光学精密机械和物理研究所，长春  130022; (4)中国科学院物理研究所，北京  100080; (5)中国科学院物理研究所，北京  100080;中国矿业大学物理系(北京校区)，北京  100083
Published: December 2020

The reflectivity of the 28.5nm Mo/Si multilayer mirrors are measured at Xingguang-Ⅱ laser facility using a flat-field grating spectrograph with the Ne-like Cr x-ray laser as a soft x-ray source. The reflectivities obtained for two samples are 0031 and 0096.
Density distributions of valence nucleons under single-particle potential model
Authors: Lin Cheng-Jian  , Zhang Huan-Qiao  , Liu Zu-Hua  , Wu Yue-Wei  , Yang Feng  , Ruan Ming  ,   中国原子能科学研究院,北京102413
Published: December 2020

Using the experimental results, we have calculated the density distributions of valence nucleons in terms of the single-particle potential model. The outside probabilities and contributions of valence nucleons given by these calculations are considered as the criterion of halo states. By studying the variation of root-mean-square radius with the separation energy, conditions for the existence of halo states are pointed out, especially of the proton halo states. These have realistic meanings for judging and searching the halo states.
Study of the effect of interface state charges on field-effect mobility of n-channel 6H-SiC MOSFET
Authors: Tang Xiao-Yan  , Zhang Yi-Men  , Zhang Yu-Ming  , Gao Jin-Xia  ,   西安电子科技大学微电子研究所,西安710071
Published: December 2020

The effect of interface state charges on the field-effect mobility of n-channel 6H-SiC MOSFET is analyzed based on the nonuniform distribution of interface state density in the energy gap. The results of the analysis show that interface state charges have the influence of lowering the field-effect mobility in n-channel SiC MOSFET. A relationship has been established between the ratio of the experimentally determined field-effect mobility to the inversion-layer carrier mobility and interface states.
Generation of tunable intensity difference squeezing light from a quasi-phase-matched OPO
Authors: Li Yong-Min  , Wu Ying-Rui  , Zhang Kuan-Shou  , Peng Kun-Chi  ,   量子光学与光量子器件国家重点实验室,山西大学光电研究所,太原030006
Published: December 2020

A 106μm all-solid-state single frequency Nd∶YVO4 laser was explored to pump a triply resonant optical parametrie oscillator(OPO) based on the periodically poled lithium niobate. When the OPO operated near degeneracy, the amplitude fluctuation correlation of the signal and idler modes was observed as their wavelengths were separated about 200nm. The measured squeezing is 04dB. The amplitude fluctuation correlation existed in a range of 17nm as we tuned the wavelengths of the signal and idler by change the crystal temperature.
Spontaneous emission from a two-level atom embedded in two-band three-dimensional photonic crystals
Authors: Chen San  , Xie Shang-Yuan  , Yang Ya-Ping  , Chen Hong  ,   同济大学物理系,上海200092
Published: December 2020

We have studied the properties of the spontaneous emission from a two-level atom embedded in two-band photonic crystals. Due to the anisotropic two-band dispersion relation, the localized and propagating fields cannot coexist, this leads to the non-quasi-oscillation behaviour of the upper level population. Thus the upper level population will tend to a constant as time goes to infinity, or decay with time in a power law, or decay with time exponentially, different from that in the isotropic one-band dispersion relation case. These properties are directly related to the relative position of the upper level from the band edge and the width of the gap.
An experimental proof for the fifth-order harmonic generation by a coherent-controlled two-pulse optical field
Authors: Liu Ting-Ting  , Wang Da-Wei  , Lu Wei-Xin  , Sun Quan  , Yang Hong  , Jiang Hong-Bing  , Gong Qi-Huang  ,   北京大学物理系，人工微结构和介观物理国家重点实验室，北京  100871
Published: December 2020

We have studied experimentally the intensity characteristic of the fifth-order harmonic radiation produced by two coherent femtosecond laser pulses with a changeable relative phase.The intensities of the harmonic generation are found to increase with the coherent degree.The maximum intensity of harmonics exhibits an asymmetric characteristic with respect to the point where the two components are superposed completely.This fact verifies the influence of deformation of the merged beam on the harmonic generation.Meanwhile,we have carried out some fundamental experiments,based on the theory of stimulated emission.
The influence of channel width and inflow rate on the critical opening-size of granular flow in two-dimensional channels
Authors: Xu Guang-Lei  , Hu Guo-Qi  , Zhang Xun-Sheng  , Bao De-Song  , Chen Wei  , Hou Mei-Ying  , Lu Kun-Quan  ,   (1)浙江大学物理系,杭州  310027; (2)中国科学院物理研究所,北京  100080
Published: December 2020

We have studied experimentlly the transition phenomenon of a granular flow from dilute flow to dense flow in two-dimensional channels. In the dense flow the outflow rate (Q) depends only on the opening (D) given by Q=aD3/2.For different inflow rates Q0 in a dilute flow, the critical opening-size with the channel relation of width (W) is given; and in a larger inflow, the critical opening-size is opproximately proportional to the square root of the inflow rate,Dc∝Q1/20.
The static friction force on a rod immersed in granular matter
Authors: Hu Lin  , Yang Ping  , Xu Ting  , Jiang Yang  , Xu Hai-Jiang  , Long Wei  , Yang Chang-Shun  , Zhang Tao  , Lu Kun-Quan  ,   (1)贵州大学物理系，贵阳  550025; (2)中国科学院物理研究所，北京  100080
Published: December 2020

The dependence of the static friction force exerted on a rod immersed in granular matter on the filling height of granules and the diameter of the rod is studied experimentally. It is observed that the friction force increases with the filling height of granules and increasing diameter of the rod. A model based on the continuous media is given, which can explain the observed results. It is demonstrated that the friction force is proportional to the diameter of the rod and the square of the filling height in the case of shallow granules, while it is a linear function of the filling height in the case of very deep granules,i.e. the friction force is proportional to the area of the interface between the rod and granules.
The role of ions(N＋２) in the dissociation of nitrogen in a direct-current glow discharge
Authors: Zhang Lian-Zhu  ,   河北师范大学物理系，石家庄  050016
Published: December 2020

A model is developed for a nitrogen direct-current glow discharge by a combination of Monte Carlo model of fast electrons and various heavy particles(N＋２，N＋，Nf),in which N+2-N２　dissociative charge transfer is incorporated,and the role of this process in nitrogen glow discharge is investigated .It is found that this process is dominant in the space of close to the cathode,and that this becomes important with increasing voltage,especially that this plays an important role at higher voltages for the production of fast atomic species(N＋，Nf) at the cathode.We have also compared our calculated results with experimental data.
Pattern formation in the dielectric barrier discharge in argon at atmospheric pressure
Authors: Yin Zeng-Qian  , Chai Zhi-Fang  , Dong Li-Fang  , Li Xue-Chen  ,   河北大学物理科学与技术学院,保定  071002
Published: December 2020

The hexagon and square gridding patterns were observed in Ar（0.5％Air） at atmospheric pressure by using a dielectric barrier discharge set-up with double water electrodes. The temporal behaviour of an individual filament in square gridding was measured. The experimental results show that the time interval between two adjacent discharges are changed between long and short alternately. The influence of the charges deposited on dielectric surface on the self-organized filament pattern has been discussed.
The mapping equation of micro-discharge in dielectric barrier discharges
Authors: Yin Zeng-Qian  , Wang Long  , Dong Li-Fang  , Li Xue-Chen  , Chai Zhi-Fang  ,   (1)河北大学物理科学与技术学院，保定  071002; (2)中国科学院物理研究所，北京  100080
Published: December 2020

The temporal behaviour of micro-discharge in the dielectric barrier discharge (DBD) in air and argon at atmospheric pressure is measured by an optical method using the special set-up of two water electrodes. The nonsymmetrical character of the filament is discovered. Considering the different effects of wall charges on the adjacent micro-discharges in DBD, we have proposed a mapping equation of discharge moment.The calculated results using different parameters show that the decay time constant of wall charges is much larger than an order of 100μs. The results deduced from the mapping equation give a good explanation to the experimental phenomenon that the time interval between two adjacent discharges of a micro-discharge varies between long one and short one alternatively. The variation range of the decay time constant of the accumulated charge is estimated.
Influence of laser field on interactions between swift molecular ions and solids
Authors: Wang Gui-Qiu  , Wang You-Nian  ,   大连理工大学物理系，三束材料改性国家重点实验室，大连  116024
Published: December 2020

Using the linearized hydrodynamic-Poisson equations, we describe electronic excitations of electron gas in solids, and derive general expressions for the induced potential in the target, and the interaction force among the ions within a molecule, in the pre-sence of a laser field. Based on the numerical solution of equations of motion for the constituent ions, the Coulomb explosion patterns and the molecular energy losses are studied for a range of laser parameters. It has been found that by increasing the laser intensity, the wake effects in the interaction potential become weaken. This weans that the deflection of the molecular axis to the direction of the projectile velocity is not significant, and the energy loss of the molecular ions is also reduced.
Investigation of lithium insertion in anode material CuSn for lithium-ion batteries
Authors: Hou Zhu-Feng  , Liu Hui-Ying  , Zhu Zi-Zhong  , Huang Mei-Chun  , Yang Yong  ,   (1)集美大学基础教学部，厦门  361021; (2)厦门大学固体表面物理化学国家重点实验室，厦门  361005; (3)厦门大学物理系，厦门  361005
Published: December 2020

An ab initio method with mixed-basis norm-conserving non-local pseudopotentials has been employed to investigate the non-carbon-baring anode material-CuSn for lithium-ion batteries. The lithium intercalation energies and their electronic structures have been calculated. The changes of volume, band structures, electronic density of states and charge density contour plots for lithium intercalation in CuSn are also presented. The characteristics of CuSn as an anode material for lithium ion batteries are also discussed. By calculation, we have found that the insertion formation energy of Li insertion CuSn electrode with zinc-blende-type structures as the host framework is about 3.5eV.
Structure and electronic properties of the low-dimensional copper systems
Authors: Wang Gui-Chun  , Yuan Jian-Min  ,   国防科技大学应用物理系，长沙  410073
Published: December 2020

Five different copper structures,including atomic chains atomic monolayers and bulk crystal,have been calculated by full-potential augmented plane wave method.For atomic mono-layers,the hexagon structure was found to be energetic favourable compared with the square structure,and the nearest bond length was also longer.For atomic chains,the same result has been obtained when the equilateral zigzag structure was compared with the linear structure.The calculated density of states (DOS) of the zigzag structure showed some unusual properties,and a band gap has been found.The DOS has been analyzed for different structures to find the relations between the electronic properties and the atomic structures.
Quantum fluctuations in the damped inductive-coupled electric circuit with resistances in the component circuits
Authors: Liang Mai-Lin  , Yuan Bing  ,   天津大学理学院应用物理系，天津  300072
Published: December 2020

Using a new quantization idea of the damped electric circuit, the inductive-coupled electric circuit is quantized when there exist resistances in the component circuits. Quantum fluctuations are calculated and the temperature effects included.
The fabrication of nc-Si/SiO2 multilayers and blue-light emission
Authors: Sui Yan-Ping  , Ma Zhong-Yuan  , Chen Kun-Ji  , Li Wei  , Xu Jun  , Huang Xin-Fan  ,   南京大学物理系,固体微结构物理国家重点实验室，南京  210093
Published: December 2020

A new fabrication method of a-Si∶H/SiO2 mutilayers (ML) is successfully employed by using layer by layer deposition of a-Si∶H sublayer and in situ plasma oxidation in a plasma-enhanced chemical vapor deposition system. Based on the constrained crystallization principle of a-Si∶H sublayer, the size-controlled nc-Si/SiO2 ML was obtained by the crystallization treatment including a rapid thermal process and furnace annealing. Blue photoluminescence is observed in the crystallized a-Si∶H/SiO2 ML at room temperature. The structure property of the nc-Si/SiO2 ML is investigated by transmission electron microscopy and Raman scattering spectroscopy. The origin of the blue-light emission is briefly discussed in combination with PL and absorption measurements.
Modal interference in dual-core photonic crystal fibers
Authors: Ren Guo-Bin  , Wang Zhi  , Jian Shui-Sheng  , Lou Shu-Qin  ,   (1)北京交通大学光波技术研究所，北京 100044; (2)北京交通大学光波技术研究所，北京 100044;河北大学物理科学与技术学院，保定 071002
Published: December 2020

The modal characteristics of dual-core photonic crystal fibers(PCFs) are analyzed by a full vector supercell lattice overlapping model. The fundamental and second-order modes of dual-core PCFs consist of a pair of even and odd modes with different polarization. The parity properties of the modal electric field for the fundamental and second-order modes are discussed. Based on the analysis of parity of the modal electric fields, we investigated the vector modal interference in dual-core PCFs.It is the interference between two same polarized modes that conributes to the inter-core coupling of power. It is shown that the optical power will oscillate from one core to the other and the phase difference between both cores is about π/2. The dependence of coupling coefficients for different polarization on wavelength is discussed.
Study of differently doped Zn0.95Cd0.05Te〈110〉single crystals as THz emitters
Authors: Wang Xiu-Min  , Xu Xin-Ｌong  , Yang Yu-Ｐing  , Shi Yu-Ｌei  , Li Fu-Ｌi  , Wang Li  , Zhang X. C.  , Kang Hyun-Shik  , Kim Tae-Kyu  ,   (1)Center for Terahertz Research,Rensselaer Polytechnic Institute,Troy,NY 12180,USA; (2)Department of Physics,College of Education,Chonbuk National University,Chonju,Korea; (3)Department of Science Education,Chonju National University of Education,Chonju,Korea; (4)首都师范大学物理系，北京 100037; (5)中国科学院物理研究所光物理实验室，北京 100080; (6)中国科学院物理研究所光物理实验室，北京 100080;首都师范大学物理系，北京 100037
Published: December 2020

Properties of differently doped Zn0.95Cd0.05Te〈110〉 crystals as terahertz (THz) wave emitter are studied using THz time-domain spectroscopy. It is observed that the THz generation efficiency increases as the DC resistivity increases when the resistivity of crystals is greater than 102 Ω·cm, but the efficiency saturates and even declines when the resistivity goes beyond 106 Ω·cm. It is revealed that the dispersion properties of crystals play an important role, besides the doping-dependent absorption in THz region.
Study of tip-sample contact process and phase contrast in tapping mode atomic force microscopy
Authors: Wang Xiao-Ping  , Liu Lei  , Hu Hai-Long  , Zhang Kun  ,   (1)中国科学技术大学结构分析实验室，合肥 230026; (2)中国科学技术大学物理系，合肥 230026;中国科学技术大学结构分析实验室，合肥 230026
Published: December 2020

The tapping-mode atomic force microscope (TM-AFM) is a very useful tool to investigate the morphology and the physical properties of sample surface. The tip-sample contact process and phase contrast of TM-AFM is studied by numerical simulation. The cantilever-tip ensemble is simply modeled as a damped harmonic oscillator driven by an actuator. The effects of tip-sample distance zc and the Young modulus of sample Es on the contact time between the tip and sample tc, the deformation of the sample surface Dz and the contrast of phase image have been investigated. The results show that both tc and Dz decrease with increasing Es or zc. A little amount of energy dissipation can occur when the tip is tapping on the sample. Moreover, when zc is fixed, the phase shift of the sample with large Es is found more remarkable than that with small Es. The experimental observation of phase image performed on Au film dispersed with Au clusters supports the simulation results.
The study of centrality dependence of rapidity densities of charged-multiplicity
Authors: Jiang Zhi-Jin  ,   上海理工大学理学院，上海 200093
Published: December 2020

Based on the theory of independent source model, the charged-multiplicity distributions in heavy ion collisions are derived which are then used to analyze the centrality dependence of the charged-multiplicity pseudo-rapidity densities, dnch/dη, in Au+Au collisions at (SNN)1/2=130 GeV in midrapidity region. The theoretical results agree well with experimental facts.
Experimental investigation of electromagnetically induced transparency with double-pumping lasers
Authors: Zhao Jian-Ming  , Zhao Yan-Ting  , Huang Tao  , Xiao Lian-Tuan  , Jia Suo-Tang  ,   山西大学物理电子工程学院,量子光学和光量子器件国家重点实验室,太原 030006
Published: December 2020

The effect of pumping laser intensity on electromagnetically induced transparency (EIT) in the cesium atomic three-level system was investigated, and the EIT against double-pumping laser was obtained. The theoretical explanation was put forward using density matrix, and the experimental results is in agreement with theoretical calculation.
The spectral assignment for the A2Σ+←X2Π transition of N2O+ ions
Authors: Xu Hai-Feng  , Guo Ying  , Li Qi-Feng  , Dai Jing-Hua  , Liu Shi-Lin  , Ma Xing-Xiao  ,   中国科学院选键化学开放研究实验室,中国科学技术大学化学物理系,合肥 230026
Published: December 2020

The spectra of N2O+ ions in A2Σ+ state have been investigated. Pure parent N2O+ ions, in the X2Π3/2,1/2(000) state, were prepared by (3+1) multiphoton ionization of jet-cooled N2O molecules using a laser beam at 360.55 nm. By introducing another laser, the parent ions were excited to the predissociative A2Σ+ state, and the fragment NO+ was detected by a time-of-flight mass spectrometer. The NO+ photofragment excitation (PHOFEX) spectra were recorded by scanning the dissociation laser in the wavelength range of 278—328 nm. The PHOFEX spectra could be attributed completely to the A2Σ+←X2Π transition of N2O+, in which most vibronic bands were observed for the first time. By considering the Fermi resonance between the ν1 and ν2 modes, the spectra were assigned, and the spectral constants, such as vibrational frequencies, anharmonic constants, and Fermi interaction constant, were obtained with relatively high reliability and precision.
Character of store and reaction of ground state multiply charged Fen+(n=1—3) ions in a Paul trap
Authors: Nie Zong-Xiu  , Li Jiao-Mei  , Jiang Yu-Rong  , Zhu Yan-Wu  , Guan Hua  , Shu Hua-Lin  , Shao Hui-Li  , Gao Ke-Lin  ,   (1)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; (2)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;北京理工大学光电工程系,北京 100081
Published: December 2020

Ground state multiply charged Fen+(n=1—3) ions have been produced by means of two separated crossed laser beams incident upon solid cast ion targets in a Paul ion trap. The decay rate of Fe3+ is measured to be 0.96 s-1 at the ground pressure 3.0×10-7 Pa and the reactive product between Fe3+ and N2 is also obtained under the pressure 1.3×10-5 Pa.
Dynamic simulations for cage-shaping of carbon atom in vapour-phase
Authors: Sheng Yang  , Ning Xi-Jing  ,   复旦大学现代物理研究所,上海 200433
Published: December 2020

A simplified dynamic model employing a velocity reset method is proposed to describe the dynamic process of nano-cluster growth in vapour-phase at high temperature. As an instance here, this model is applied to simulate the cage-shaping of carbon atoms, providing some interesting information which is found to be in better agreement with relevant experimental observations.
Theoretical calculation of structures and properties of Ga6N6 cluster
Authors: Hao Jing-An  , Zheng Hao-Ping  ,   同济大学玻耳固体物理研究所,上海 200092
Published: December 2020

The first principle, all-electron, ab initio calculations have been performed for cluster Ga6N6, based on the density functional theory. Ten possible structures and related electronic structures are obtained. For the most stable structure, the mean binding energy of a pair atoms of GaN is 9.748 eV, so the structure may exist. Compared with the results of clusters Ga3N3 and Ga5N5 calculated by other people, however, the cluster Ga6N6 may not be the “magic number” cluster. The Fermi level of cluster Ga6N6 in the most stable structure is partly occupied with EF=-5.2972 eV, which means “metallicity”. The cluster Ga6N6 has no spin magnetic moment. The electron affinity, ionization energy, and transition energies of cluster Ga6N6 are also calculated. This work should be helpful to the complete study of structures and properties of clusters GanNn.
Structure and magnetism of 3d series (TM)4 clusters
Authors: Lü Jin  , Xu Xiao-Hong  , Wu Hai-Shun  ,   山西师范大学化学与材料科学学院,临汾 041004
Published: December 2020

Based on the first-principle, we optimize all geometric structures of (TM)4 clusters, calculate the energy, frequency and magnetism of (TM)4 clusters by using the local spin density approximation(LSDA) and generalized gradient approximation(GGA) density functional theory. We confirm the ground-state structures of (TM)4 clusters, study their magnetism, binding energy and average interatomic distance systematically, and find that in the 3d series (TM)4 clusters, the local magnetic moment of Mn4 cluster is the largest, that of the V4 cluster is the weakest. Except that the Cr4 cluster in LSDA and GGA shows anti-ferromagnetic coupling，and the V4 cluster in GGA shows also anti-ferromagnetic coupling, other clusters all show ferromagnetic coupling.
Studies on structures and photoelectron spectroscopy of GamPn and GamP-n clusters
Authors: Jia Wen-Hong  , Wu Hai-Shun  ,   山西师范大学化学与材料科学学院,临汾 041004
Published: December 2020

Using density functional theory associated with the B3LYP method with 6—31G* basis set, we have carried out the optimizing calculations of the geometry, electronic state and vibrational frequency for GamP-n(m+n≤5) clusters, moreover, discussed the vertical detachment energy of GamP-n and the adiabatic electron affinities of GamPn. The results show that the structures with singlet have higher symmetry, while the one with doublet has lower symmetry.
The vectorial nonparaxial propagation method of the few-cycle ultrashort pulsed beam in free space
Authors: Lu Da-Quan  , Hu Wei  , Yang Zhen-Jun  , Zheng Yi-Zhou  ,   华南师范大学传输光学实验室,广州 510631
Published: December 2020

Based on the purterbative method which was developed by Lax et al, and by using of the Fourier transform, we obtain a vectorial nonparaxial correction method to the propagation of the few-cycle pulsed beam in free space. the first-order of the transverse component of the correction is the same as that of Fu's in the frequency domain, and is more convenient to obtain the analytical nonparaxial solution in the temporal domain. It is shown in the examples and the analysis that the vector corrections must be included in any study that wants to go beyond the scalar paraxial solution. From the examples, we find that the spatial distribution of the vectorial nonparaxial correction would be influenced by the temporal distribution of the pulse.
Incoherent multimode spatially bistable soliton
Authors: Chen Yuan-Yuan  , Wang Qi  , Shi Jie-Long  ,   上海大学理学院物理系,上海 200436
Published: December 2020

Incoherent multimode bistable soliton can exist in higher-order nonlinearity media. Using the coherent density method, we obtain the analytical expression of the incoherent multimode bistable soliton, and the higher-order nonlinearity controls the existence and the intensity peak of bistable solitons. We find the cut-off wavelength, the minimum width of the incoherent beam and the nonlinearity condition for the media, and then we study the propagation characteristics of coherent components that consist of incoherent multimode beams. According to the stability criterion, we demonstrate rigorously that the incoherent multimode bistable soliton can propagate stably against small perturbation.
Study on multi-wavelength photochromic storage of diarylethene
Authors: Qi Guo-Sheng  , Xiao Jia-Xi  , Liu Rong  , Jiang Pei-Jun  , She Peng  , Xu Duan-Yi  ,   清华大学精密仪器与机械学系,光盘国家工程研究中心,北京 100084
Published: December 2020

Multi-wavelength photochromic storage is a new optical storage method with high storage capacity based on photochromic principle. The storage mechanism, the system structure and disc structure of multi-wavelength photochromic storage are presented. Three-wavelength photochromic storage experiment on a three-wavelength photochromic storage system is carried out. The results show that three materials used in the experiment can be used in multi-wavelength photochromic storage and the contrast of the readout signal is high and little crosstalk is generated. The contrast of the readout signal remains high after low-speed reading out 50 times.
Statistic properties of photon in the system of two coupling atoms interacting with two-mode squeezed vacuum field in Kerr medium
Authors: Fang Jia-Yuan  , Huang Chun-Jia  , Huang Zu-Hong  , Zhou Ming  ,   长沙理工大学物理与电子科学系，长沙 410077
Published: December 2020

The statistic properties of photons in the system of two-mode squeezing vacuum field interacting with two coupling atoms in Kerr medium are studied by means of quantum theory.The influences of coupling constant χ, initial squeezed parameter r and the atomic initial state are discussed. The results obtained by means of numerical method show that the photon bunching and anti-bunching appear alternately, and the correlation of the two modes of light is both positive and non-classical. The periodical collapse-revival phenomenon of the time evolution of the second-order coherence degree of the two-mode field appears due to the influence of the Kerr effect. The periods of the collapse-revival become short up to disappearance with increasing Kerr effect.
Modulation instability of non-paraxial beams for self-focusing Kerr media
Authors: Feng Min  , Wei Qing  , Shi Jie-Long  , Xue Yun  ,   上海大学理学院物理系，上海 200436
Published: December 2020

Propagation stability of non-paraxial beam in nonlinear Kerr media is investigated by using the linear stability method.Both theoretical analysis and numerical simulation show that the modulation instability gain spectrum has three different distribution features, which are determined by ap0, where a and p0 represent the non-paraxial parameter and the incident power, respectively. Furthermore, the corresponding criterion is given to distinguish the three different distributions.
Optical transmission spectra of one-dimensional photonic crystals with a mirror symmetry
Authors: Du Gui-Qiang  , Liu Nian-Hua  ,   南昌大学材料科学研究所，南昌 330047
Published: December 2020

We have studied the optical transmission of one-dimensional photonic crystals with a mirror symmetry. One or more complete transmission peaks exist in the forbidden gap. A simple recursion relation is derived by means of the mathematical induction to calculate the frequencies of the complete transmission peaks. In the center there is always a transmission peak due to the mirror symmetry. Other peaks are dependent on positions of the defects and the refractive index. If the structure is chosen properly, a wider transmission band can be obtained.
The reflectance calibration of soft x-ray planar mirror with different grazing angle
Authors: Sun Ke-Xu  , Yi Rong-Qing  , Yang Guo-Hong  , Jiang Shao-En  , Cui Yan-Li  , Liu Shen-Ye  , Ding Yong-Kun  , Cui Ming-Qi  , Zhu Pei-Ping  , Zhao Yi-Dong  , Zhu Jie  , Zheng Lei  , Zhang Jing-He  ,   (1)哈尔滨工业大学精密工程研究所，哈尔滨 150001; (2)中国工程物理研究院激光聚变研究中心，高温高密度等离子体物理国家重点实验室，绵阳 621900; (3)中国科学院高能物理研究所同步辐射实验室，北京 100039
Published: December 2020

The reflectivity of grazing soft x-ray planar mirror is studied.The Beijing Synchrotron Radiation Facility-3W1B beam line with beam current 40—120 mA,the storage ring electron energy 2 GeV,photon energy 50—1500 eV are used.We have improved the calibration method.The x-ray diode detectors of planar mirror facility are replaced by AXUV-100.Therefore,2 to 3 orders of magnitude for the ratio of signal to noise can be increased,and the calibration region from (150—270 eV)to (50—1500 eV)is expanded.The reflectivity calibration curves for C,Si,Ni,and Au planar mirror in different grazing angles are given.Finally,the values obtained in experiment and calculation are compared and analyzed.
New solitary wave solutions for nonlinear wave equation with fifth-order stronger nonlinear term
Authors: Naranmandula  , Wunenboyn  , Wang Ke-Xie  ,   (1)吉林大学物理学院，长春 130023; (2)吉林大学物理学院，长春 130023;内蒙古民族大学物理与机电学院，通辽 028043; (3)内蒙古民族大学物理与机电学院，通辽 028043
Published: December 2020

A new function-transformation method is proposed and four kinds of explicit exact solitary wave solutions of the Lienard equation, the generalized PC equation, the important nonlinear wave equation in mechanics, which have a fifth-order stronger nonlinear term, are obtained by a combination of the function-transformation method and the direct integral method. The method proposed in this paper can also be applied to other nonlinear equations with higher-order nonlinear terms.
A designed model and related theoretical analysis on optical pulse compressor based on a SOA and cascaded NOLM
Authors: Wu Jian-Wei  , Xia Guang-Qiong  , Wu Zheng-Mao  ,   (1)西南师范大学物理学院，重庆 400715; (2)西南师范大学物理学院，重庆 400715;重庆大学教育部光电技术与系统重点实验室，重庆 400044
Published: December 2020

A designed model of the optical pulse compressor, which is based on a semiconductor optical amplifier and cascaded nonlinear optical loop mirror, has been presented in this paper. The numerical simulations reveal that a ps optical pulse can be compressed into a fs pulse without pedestal.
The attenuation of electromagnetic waves by inhomogeneous spherically symmetric plasma
Authors: Song Fa-Lun  , Cao Jin-Xiang  , Wang Ge  ,   中国科学技术大学近代物理系，合肥 230027
Published: December 2020

A simulation model has been developed to calculate the transmission and absorption of electromagnetic waves by inhomogeneous spherically symmetric plasma.In this model,the nonuniform sphere is modeled by numbers of concentric spherical shells,and each has a fixed electron density.Using the geometrical optics approximation and considering that the phase coefficient and attenuation coefficient are vectors,we have studied the property of absorption and transmission of electromagnetic waves by inhomogeneous spherically symmetric plasma for different collision frequency,central plasma density and frequency of electromagnetic waves for three typical density distribution profiles.Some useful results are obtained.
Application of Monte Carlo simulation to the research of ions transport plasma sheaths of glow discharge
Authors: Wang Jian-Hua  , Jin Chuan-En  ,   合肥工业大学理学院，合肥 230009
Published: December 2020

In this paper， Monte Carlo method was used to simulate the motion of ions in the cathode fall zone of glow discharge. Energy distributions and angle distributions at different pressures and voltages are presented. The simulations are based on two main scattering processes of charge transfer and elastic scattering. Either the ion energy dependence or independence of collision cross-sections is taken into account. For elastic scattering, the potential interaction and hard-sphere models are considered. The parameter Pdc has a great influence on the energy distribution, but the angle distribution of ions is not sensitive to discharge parameters. Simulation results obtained by different models have been compared and discussed. The model that includes charge transfer and potential interaction scattering processes and is based on the dependence of collision cross-section on the ion energy is obviously the best.
Penetration and attenuation of SMB fueling in tokamak plasma
Authors: Jiao Yi-Ming  , Zhou Yan  , Yao Liang-Hua  , Dong Jia-Qi  ,   (1)电子科技大学光电信息学院，成都 610054;核工业西南物理研究院，成都 610041; (2)核工业西南物理研究院，成都 610041
Published: December 2020

In this paper, a discussion and an optimizing numerical analysis of the penetration and attenuation of the thermonuclear tokamak plasma fueling by the supersonic cluster molecular beam(SMB) has been presented.The cluster formation and dissolution,SMB adiabatic expansion,shielding and cooling effect are all taken into account.An optimized numerical model is applied in the analysis and shown to be in good agreement with the experimental observations.The possibility for fueling large tokamak plasmas with SMB injection is explored.
Chaotic electron motion in a traveling-wave tube amplifier
Authors: Hao Jian-Hong  , Ding Wu  ,   (1)北京应用物理与计算数学研究所，北京 100088; (2)石家庄师范专科学校，石家庄 050801;华北电力大学信息工程系，北京 102206
Published: December 2020

On the basis of the self-consistency equations, the chaotic behavior of electron orbits is studied numerically in a traveling-wave tube amplifier. The results show that motion orbits of electrons in phase space can become chaotic as the current increases, and the chaotic orbits are affected by the detuning. In temporal scale, appearance of chaotic motion of electrons is earlier than one of limit cycle and chaotic oscillation of the field. In comparison with the limit cycle oscillation of the field, the threshold current for the onset of chaotic orbits of electrons is low. In the soft nonlinear regime at which the field exhibits limit cycle oscillation, the chaotic region increases and gradually engulfs the whole phase space as the current increases. In the hard nonlinear regime at which the field exhibits chaotic behavior, the chaotic orbits of electrons occupy almost everywhere in the phase space. The pattern of chaotic motion of electrons is unchanged for a certain current; the characteristic of the limit cycle and chaotic oscillation of the field is certain, but their output power is uncertain in a certain current range.
Optimization of the parameters for a SPIDER
Authors: Chai Lu  , He Tie-Ying  , Yang Sheng-Jie  , Wang Qing-Yue  , Zhang Zhi-Gang  ,   (1)天津大学精密仪器与光电子工程学院超快激光研究室，国家教育部光电子信息技术科学重点实验室,天津 300072; (2)天津大学精密仪器与光电子工程学院超快激光研究室，国家教育部光电子信息技术科学重点实验室,天津 300072;天津大学理学院,天津 300072
Published: December 2020

The correlations among three important parameters in SPIDER, the time delay τ between the test pulse replicas, the frequency shear Ω and the second-order dispersion φ determined from a stretcher, are investigated. The results show that there are different optimum time delays τ for different test pulses with a fixed φ. The optimum time delays τ will increase as the duration of test pulse gets longer. However, the measurement may fail if the frequency shear Ω, which is direct proportional to the time delay τ, becomes too large to meet the condition of the sum-frequency. Therefore, for different widths of pulses, the magnitude of φ should be properly adjusted for selecting the optimum τ.
The microstructure and properties of tetrahedral amorphous carbon films deposited by filtered arc with accelerating at different energetic grades
Authors: Zhu Jia-Qi  , Wang Jing-He  , Meng Song-He  , Han Jie-Cai  , Zhang Lian-Sheng  ,   (1)承德石油高等专科学校，承德 067000; (2)哈尔滨工业大学精密工程研究所，哈尔滨 150001; (3)哈尔滨工业大学特种环境复合材料技术国防科技重点实验室，哈尔滨 150001
Published: December 2020

Tetrahedral amorphous carbon (ta-C) films were deposited on single crystalline silicon by accelerating the species with different impinging energetic grades produced by static-electricity pulse substrate bias from 0 to -2000 V. The microstructure of the ta-C films consist of amorphous sp3 hybridization skeleton enchased with sp2 clusters with sizes less than 1 nm by visible Raman measurement. At low energetic grade, sp3-rich energetic window, and sub-high energetic grade, the more the content of sp3 in the film, the smoother the surface of the film. The relationship between the impinging energy of the species and the surface morphology can be illustrated perfectly in the light of subimplantation growth mechanism. Nevertheless, at high energetic grade, the impinging ions with appropriate energy and angle can sputter and smoothen the surface, even the roughness is lower than the surface of the films with the most sp3. The hardness and Young's modulus of the films deposited at high energetic grade (-2000 V) are higher than those of the films prepared on the floating conditions. At the same time, the critical scratching load of the films deposited with the substrate bias of -2000 V is even larger than the one of the sp3-rich films.
The study on the Peierls phase transition of one-dimensional organic conductors
Authors: Zhang Hong-Qun  ,   北京师范大学物理系，北京 100875
Published: December 2020

According to Peierls phase transition theory based on the electron-phonon interaction, the Peierls phase transition temperature of a one-dimensional organic conductor tetrathiafulvalene-tetracyanoquinodimethane is computed using the deformation potential model with the data calculated by a semi-empirical crystal orbital method. The mechanism of the metal-insulator phase transition in this conductor is also discussed.
Study of dopant influence on megnetic-field-induced Freedericksz transition of liquid crystal
Authors: Lin Zi-Yang  , Xiang Ying  , Li Tao  ,   (1)深圳大学光电子学研究所，广东省光电子器件与系统重点实验室，深圳 518060; (2)中山大学化学系，广州 510275; (3)中山大学物理系，广州 510275
Published: December 2020

The optical phase retardation method is used in this paper. Based on the experiments on magnetic-field-induced Freedericksz transition of planar nematic liquid crystal, doped with trace bulin, fibre protein and double-azo etc, the trace adulteration effects on the transition of planar nematic liquid crystal are discussed; experimental curves and numerical calculation curves are given. Numerical calculation results are in agreement with measured results. It is shown that different impurities whose magnetic property, molecule shape and size are different, lead to different magnetic-field-induced Freedericksz transition, which is ulteriorly illuminated with the experiment on magnetic-field-induced Freedericksz transition of planar nematic liquid crystal doped with 2-benzothiazolethiol-linked porphyrinatozinc(Ⅱ).
The contrast on low-temperature physical property of heavy electron compounds CeCu5.8M0.2(M=Ni, Zn, Cd)
Authors: Meng Ji-Bao  , Chen Zhao-Jia  , Luo Jian-Lin  , Jing Xiu-Nian  , Wang Nan-Lin  ,   中国科学院物理研究所,北京  100080
Published: December 2020

In this paper, we report the resistance, specific heat and susceptibility of heavy electron compounds CeCu5.8M0.2(M=Ni，Zn，Cd) as functions of temperature from 1.8 K to 300 K. The effects of magnetism, valence and atom size of different doping elements on Kondo temperature TK, coherent temperature TRmax (e.g. the temperature of maximum resistance) and other parameters have been discussed.
Modulation effect of transverse alternating and direct currents on I-V characteristics in blue bronze K0.3MoO3
Authors: Zheng Yi  , Shen Jing-Qin  , Chen Xue-Zhi  , Wang Hong-Tao  , Xu Zhu-An  , Zhang Xuan-Jia  ,   (1)温州师范学院物理与电子信息科学系，温州 325027; (2)浙江大学物理系，杭州 310027
Published: December 2020

We have investigated the transverse alternating and direct current effect on the charge-density wave (CDW) dynamical properties in K0.3MoO3 by measuring I-V characteristics.The results show that,no matter whether DC or AC transverse current is used,the CDW depinning field (Et) along the longitudinal direction is effectively suppressed as the transverse current increases.But the effect of AC current on I-V characteristics is weaker,and probably closer to the intrinsic effect.A frequency dependence of transverse AC modulation effect was observed.
Giant Rashba spin splitting in HgTe/HgCdTe quantum wells
Authors: Qiu Zhi-Jun  , Gui Yong-Sheng  , Shu Xiao-Zhou  , Dai Ning  , Guo Shao-Ling  , Chu Jun-Hao  ,   中国科学院上海技术物理研究所红外物理国家重点实验室，上海 200083
Published: December 2020

Giant Rashba spin splitting has been found in n-HgTe/HgCdTe quantum wells with an inverted band structure by studying the beating patterns in Shubnikov-de Haas oscillations. Fast Fourier transformation, node positions, as well as numerical simulations, are used to deduce the Rashba spin-orbit splitting and result in an excellent agreement in Rashba spin splitting energy (28-36 meV).
“The quasi invariant V” analysis for the chaotic behavior of Lorenz map in the nearest neighborhood of the second threshold of laser
Authors: Song Li-Ping  , Guo Qi-Zhi  , Tan Wei-Han  ,   (1)上海大学物理系,上海  200436; (2)上海大学物理系,上海  200437; (3)上海大学物理系,上海  200438
Published: December 2020

In order to study the laser oscillation instability, in this paper we present the “quasi invariant V” method for analysis of the chaotic behavior of Lorenz map in the nearest neighborhood of the second threshold of laser, and demonstrate the relation between initial value V0 and the time tc for the occurrence of chaos, i.e. V0tc equals a constant C0 depending on the parameter σ,b,r of the system.
Huge magnetoresistance effect of highly oriented pyrolytic graphite
Authors: Du You-Wei  , Wang Zhi-Ming  , Ni Gang  , Xing Ding-Yu  , Xu Qing-Yu  ,   (1)南京大学固体微结构国家重点实验室，南京 210093; (2)中国科学院物理研究所北京电子显微镜实验室，北京 100080
Published: December 2020

Graphite is a quasi-two-dimensional semimetal. However, for usual graphite the magnetoresistance is not so high due to its small crystal size and no preferred orientation. Huge positive magnetoresistance up to 85300% at 4.2 K and 4950% at 300 K under 8.15 T magnetic field was found in highly oriented pyrolytic graphite. The mechanism of huge positive magnetoresistance is not only due to ordinary magnetoresistance but also due to magnetic-field-driven semimetal-insulator transition.