bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and analytic potential energy function of the molecules BeH, H2 and BeH2
Authors: Du Quan  , Wang Ling  , Chen Xiao-Hong  , Wang Hong-Yan  , Gao Tao  , Zhu Zheng-He  ,   (1)四川大学原子与分子物理研究所,成都  610065; (2)西华大学理化学院,成都  610039; (3)西南交通大学理学院,成都  610031
Published: December 2020

Quadratic configuration interaction calculation (QCISD) and B3LYP methods have been used to optimize the possible ground-state structures of H2, BeH and BeH2 molecules. The results show that their ground electronic states are H2(1Σg), BeH(2Σ) and BeH2(1Σg); the stable structure of BeH2molecule is of D∞h symmetry. The Murrell-Sorbie potential energy function with 8 parameters of BeH and H2 molecule has been derived from the least square method, according to which spectral data and force constants are deduced. The analytical potential energy function of BeH2 is derived from the many-body expansion theory. Since BeH2(D∞h) formed from H+BeH has a deep potential trap, the complex com pound molecule of H-Be-H is easily formed. The reaction of Be+H2→HBeH　with ΔH=-1.4654eV is an exothermic reaction.
Ultrahigh-speed all-optical encoder based on four-wave mixing in semiconductor optical amplifiers with PolSK modulated signals
Authors: Li Pei-Li  , Huang De-Xiu  , Zhang Xin-Liang  ,   (1)华中科技大学武汉光电国家实验室，武汉  430074; (2)南京邮电大学光电工程学院，南京  210046
Published: December 2020

A novel scheme for ultrahigh-speed all-optical encoder based on four-wave mixing （FWM） in semiconductor optical amplifiers （SOAs） with PolSK modulated signals is proposed. Considering the polarization dependency of SOA, a comprehensive polarization-dependent broad-band dynamic model is presented. By numerical simulation, this kind of all-optical encoder is theoretically realized, and the effects of two input signal powers, injected current, and polarization dependency of SOA on the output performance of the encoder are analyzed.
Study on the thermal interface resistance of the helix slow-wave structure
Authors: Han Yong  , Liu Yan-Wen  , Ding Yao-Gen  , Liu Pu-Kun  ,   (1)中国科学院电子学研究所，中国科学院高功率微波源与技术重点实验室,北京  100190; (2)中国科学院电子学研究所，中国科学院高功率微波源与技术重点实验室,北京  100190；中国科学院研究生院,北京  100049
Published: December 2020

The thermal interface resistance of the helix slow-wave structure （SWS） has been studied theoretically and experimentally. The effect of the thermal resistance at two interfaces on heat dissipation capability of the SWS is analyzed. A novel method to calculate the thermal interface resistance has been developed, and its accuracy and feasibility were validated by experiments. With this method, the thermal interface resistances at two interfaces can be calculated separately, considering the variation of the material performance with the temperature changes. This novel method is used to study the effect of the rod material and the assembling method on the thermal interface resistance.
First-principles investigation on the role of ions in ferroelectric transition of BiFeO3
Authors: Sun Yuan  , Huang Zu-Fei  , Fan Hou-Gang  , Ming Xing  , Wang Chun-Zhong  , Chen Gang  ,   (1)吉林大学材料科学与工程学院材料科学系，长春 130012; (2)吉林大学材料科学与工程学院材料科学系，长春 130012;吉林师范大学凝聚态物理研究所，四平 136000
Published: December 2020

The electronic properties of multiferroic BiFeO3 with paraelectric paramagnetic phase at high-temperature and ferroelectric antiferromagnetic phase are calculated using density functional theory with spin-polarized generalized-gradient approximation (GGS) and plane wave pseudopotentials. study of Born effective charges shows that the greatest contributor to the ferroelectric distortion is Bi atoms' displacement. We obtained very large theoretical electric polarization, which agrees very well with the results of thin-film test. The calculation shows that BiFeO3 ground state has G type anti-ferromagnetic order and the theoretical magnetic moments of Fe ion accord with experimental values. After ferroelectric phase transformation, the chemical bond changes much due to Bi-6s and Bi-6p state charge transfer, and the effect of Bi-6s electrons becomes more pronounced. Partial density of states calculation indicates that the energy split between bonding orbit of Bi-6p state and anti-bonding orbit is bigger than that between other electronic states, by which covalent bond between Bi-6p state and O-2p state is strengthened, which is the origin of off-center displacement. Thus the discussion about the BiMnO3 is testified. Bi-6s state is polarized due to the static electric repulsion, but does not take part in the hybridization of Bi-6p and O-2p electrons. The charge transfer originates from its weak covalent interaction with the O-2s, 2p orbits, by which the Bi-6s state electronic polarization is reinforced. This kind of covalent interaction helps the relative replacement of Bi-O, which is the reason for the strong systemic electric polarization.
Directional defect modes in twelve-fold-symmetry quasicrystal
Authors: Feng Zhi-Fang  , Liu Rong-Juan  , Li Zhi-Yuan  ,   (1)北京化工大学理学院，北京  100029; (2)中国科学院物理研究所光物理实验室，北京  100190
Published: December 2020

The translational symmetric associated with photonic crystal is absent in the rotationally symmetric quasiperiodic photonic crystal （QPCs）, and the quasiperiodic photonic crystal has more defect modes than photonic crystal because of it. In this paper, we investigate the defect modes in the 12-fold quasiperiodic photonic crystal by the multiple scattering method. We find that there is a directional defect mode in quasiperiodic photonic crystal. When the defect rotates against the centre of the symmetry, there emerges a new defect mode.
Two-step resonant photoionization spectra of Sm atom
Authors: Zhao Hong-Ying  , Dai Chang-Jian  , Guan Feng  ,   显示材料与光电器件教育部重点实验室，天津  300191；天津理工大学理学院，天津  300384
Published: December 2020

Resonant ionization spectra of Sm atom are studied with a two-step photoexcitation and photoionization method. Two different excitation paths are carried out as the following: In the path 1, the first laser whose wavelength is fixed at 478.44nm excites the Sm atom from the 4f66s2［7F1］ state to the 4f66s6p［7D1］ state，and then the second laser whose wavelength λ2 is scanned from 480nm to 530nm excites it further to the high-lying state with even parity. In the path 2, the first laser whose wavelength is fixed at 574.81nm excites the Sm atom from the 4f66s2［7F2］ state to the 4f66s6p［5G3］ state，and then the second laser whose wavelength λ2 is scanned from 460nm to 470.5nm excites it further to the high-lying state with even parity. These Sm atoms in the high-lying state are probed by photoionization via the third laser. All together 26 and 76 states of Sm atom in the 39465—39932 cm-1 and the 40000—42010 cm-1 energy region, respectively, have been detected below the first ionization limit. The energy levels and relative strengths of these states have been determined. Among them, 51 states are newly discovered, while the rest agree well with the values published in literature. In addition, efforts are also made to determine their spectral designation.
Study on the high temperature line intensities of the symmetric-top molecule NH3
Authors: Song Xiao-Shu  , Yu Chun-Ri  , Yan An-Ying  , Cheng Xin-Lu  , Yang Xiang-Dong  ,   (1)安庆师范学院物理与电气工程学院，安庆  246133; (2)贵州师范大学理学院，贵阳  550001; (3)四川大学原子与分子物理研究所，成都  610065; (4)西南民族大学信息工程学院，成都  610041
Published: December 2020

The line intensities of 0300 a—0000 s transition of the symmetric-top NH3 molecule at high temperature were obtained by directly calculating the partition functions while regarding the rotationless transition dipole moment squared as a constant. The calculated values of the total internal partition sums (TIPS) are consistent with the data of HITRAN database within 0.19% at 296 K. The calculated line intensities data at 2000 K and 3000 K are also in excellent agreement with the data in HITRAN database with discrepancies less than -0.65% and -1.77%, which strongly supports the calculations of partition function and line intensity at high temperature. Then we extended the calculation to higher temperature. The line intensities and simulated spectra of 3ν2 band of the symmetric-top NH3 molecule at 4000 K and 5000 K were reported. The results are of significance for the study of the high-temperature molecular spectra in experiment and in theory.
The effects of intelligent traffic light on the crossing traffic flow
Authors: Li Sheng-Chun  , Kong Ling-Jiang  , Liu Mu-Ren  , Zheng Rong-Sen  ,   (1)广西师范大学物理与电子工程学院,桂林  541004; (2)玉林师范学院物理与信息科学系,玉林  537000
Published: December 2020

Using the improved NaSch traffic model, we simulate the traffic flow on the crossroad under open boundary condition. The simulations are controled by ordinary traffic light and intelligent traffic light respectively. The results show that the average speed and the traffic flux under control of the later are greater than that controled by the former. Moreover, the vehicles controled by intelligent traffic light can cut down the unnecessary waiting time.
The effects of decelerating lane in the off-ramp system
Authors: Li Sheng-Chun  , Kong Ling-Jiang  , Liu Mu-Ren  , Zheng Rong-Sen  ,   (1)广西师范大学物理与电子工程学院,桂林  541004; (2)玉林师范学院物理与信息科学系,玉林  537000
Published: December 2020

In this paper,we study the effects of decelerating lane in the off-ramp system of freeway. Based on the NaSch model of traffic flow, a model of two-lane system with off-ramp is established. From the numerical simulations, we obtain the fundamental diagrams of traffic flow under different parameters. Moreover, we compare the road including decelerating lane with the road without it.
Preparation of SiOx nanowires in different atmosphere, their morphology, PL and FTIR properties
Authors: Zheng Li-Ren  , Huang Bai-Biao  , Wei Ji-Yong  ,   (1)山东大学晶体材料国家重点实验室，济南 250100; (2)山东大学晶体材料国家重点实验室，济南 250100；山东大学化学与化工学院，济南  250100; (3)泰山学院物理与电子科学系，泰安  271021；山东大学晶体材料国家重点实验室，济南 250100
Published: December 2020

Highdensity SiOx nanowires were fabricated on a largescale using carbonassisted CVD method by Fe—Al—O catalyst at 1140℃ in flowing N2/H2,N2 and NH3 atmospheres.The SiOx nanowires have uniform diameters of 20—300 nm and lengths of up to a few hundred micrometers. SEM, TEM, EDS, FTIR and PL were preformed to characterize the microstructure, composition and optical performance of the nanowires. Energy dispersive Xray spectral analysis reveals that the nanowires consist of Si and O elements in an atomic ratio of approximately 1∶18The nanowires show IR absorption peaks at 482,806,1095 and 1132 cm-1. The PL peak of the nanowires is located at 440 nm （283eV）.The PL inensity of the SiOx nanowire （N2） is 104 times that of the SiOx nanowire（N2/NH3）.
Theoretical study on bremsstrahlung of high energy electrons
Authors: Wei Xi-Ye  , Li Quan-Feng  , Yan Hui-Yong  ,   (1)清华大学工程物理系，北京  100084; (2)中国工程物理研究院核物理与化学研究所,绵阳  621900
Published: December 2020

Bremsstrahlung will be produced when the metal target is bombarded by high energy electrons. Bremsstrahlung characteristics is discussed under the condition of optimal bremsstrahlung efficiency for the purpose of improving its quality. This paper simulates the bremsstrahlung characteristics, combining theoretical analysis with MCNP/4C program. Electron yield characteristics, photon yield of conic collimator, angular distributions and energy spectrum distributions are simulated for targets of different thickness and materials for 10 and 20?MeV electrons. The simulation results show that photon efficiency, emitted electron and photon flux distribution is related to material and thickness of the target. And the maximum photon yield of bremsstrahlung is mainly dependent on the electron energe range, and related to atomic number. Thus the relevant boundary conditions and characteristics are obtained under the optimal bremsstrahlung efficiency of different targets for 10 and 20?MeV electrons.
Relativistic distorted-wave calculation of electron impact excitation cross sections of be-like N3+ and O4+ ions
Authors: Liu Yan-Jun  , Dong Chen-Zhong  , Jiang Jun  , Xie Lu-You  ,   (1)西北师范大学物理与电子工程学院,兰州  730070; (2)西北师范大学物理与电子工程学院,兰州  730070；西北师范大学与中国科学院近代物理研究所极端环境原子分子物理联合实验室,兰州  730070
Published: December 2020

By using a fully relativistic distortedwave method, the electron impact excitation cross sections of Belike N3+ and O4+ ions from the ground state 2s21S to 2s2p 1,3P, 2p23P, 1D and 1S 2s2p and from the metastable 2s2p 3P to 2p23P have been calculated systematically. Meanwhile, the correlation effects of target states are also discussed. For the low energy collisions the correlation effects play a very important role, and accurate target wavefunctions are needed, but for the high energy collisions, the more correlation effects are not so important. For twoelectron excitations, the configuration interactions are very important and the excitations from ground state to the 2p23P0 and 1S0 have larger cross sections than the other tow electron excitations.
Hydrothermal synthesis of BiVO4 powder with different morphologies and structures
Authors: Zhang Ai-Ping  , Zhang Jin-Zhi  ,   北方工业大学理学院，北京  100144
Published: December 2020

BiVO4 powders with different morphologies and structures were synthesized by hydrothermal method by controlling the nBi/nV，reaction temperature，reaction time and pH value. Xray diffraction，transmission electron microscope，scanning electron microscope，Raman，Fourier transform infrared and ultravioletvisible absorbance spectroscopy were used to characterize the products. The results showed that highly crystalline monoclinic scheelite structure of BiVO4 was obtained through increasing the nBi/nV or the pH value. By controlling different reaction temperature and reaction time，monoclinic scheelite structure BiVO4 with different grain sizes and different internal structures were obtained. Besides，BiVO4 with different morphologies can be controlably synthesized when using different surfactants.
The study of Raman excited virtual state：a case study of methylviologen
Authors: Fang Chao  , Wu Guo-Zhen  ,   清华大学物理系，原子分子纳米教育部重点实验室，北京  100084
Published: December 2020

An algorithm is employed to elucidate the molecular bond polarizabilities of methylviologen, including their temporal relaxations，from Raman intensities. The main characteristic of the Raman excited virtual state of MV is that the excited electrons tend to flow to the molecule periphery and to the bond connecting its two rings due to electronic repulsion. The bond electron densities of its ground state can be mapped out by the temporal bond polarizabilities at the final stage of relaxation.
Experiment study of orientation and reorientation quantum dynamics of single dye molecules at room temperature
Authors: Zhang Guo-Feng  , Cheng Feng-Yu  , Jia Suo-Tang  , Sun Jian-Hu  , Xiao Lian-Tuan  , Zhang Fang  ,   山西大学物理电子工程学院，量子光学与光量子器件国家重点实验室，太原  030006
Published: December 2020

We have studied experimentally the dipole orientation and reorientation dynamics of single dye molecules at room temperature. The dipole rotation of individual dye molecules which are physisorbed to glass and embedded in spin-cast polymer films is measured with the confocal scanning optical microscopy and the method of fluorescence polarization analysis, the probability of reorientation of single molecules found to be about 5%—9% when embedded in polymer, and about 26% when absorbed to glass by using the statistic analysis. It is found the quantum jumps for molecule dipole reorientation are distributed in several different polarization states by measuring the polarization degree of fluorescent photons.
Monte Carlo simulation of transfer-characteristics of electromagnetic wave propagating in soot
Authors: Huang Chao-Jun  , Liu Ya-Feng  , Long Shu-Ming  , Sun Yan-Qing  , Wu Zhen-Sen  ,   (1)陕西理工学院物理系，汉中  723001; (2)西安电子科技大学理学院，西安  710071
Published: December 2020

Based on equivalent particulate model and fractal theory，using the Mie theory and discrete-dipole approximation，the scattering by aggregated soot particles of the 06328?μm incident wave is computed. Then based on radiation transportation theory，and numerically calculating the transfer-characteristics of electromagnetic wave propagating in soot by using Monte Carlo method，the author gets the relationships of the reflectivity and transmissivity of soot with the changing incident angles，soot thickness and density，and analyses these factors affecting the reflectivity and transmissivity. This provides an efficient approach to the research of transfer-characteristics of electromagnetic wave in poly-disperse highly dense media.
Study of diffuse reflectance based on a hybrid diffusion approximation and simulating experiment
Authors: Tian Hui-Juan  , Liu Ying  , Wang Li-Jun  , Zhang Zhi-Bo  , Xiao Li-Feng  ,   天津大学理学院物理系，光电信息技术科学教育部重点实验室，天津  300072
Published: December 2020

A modified diffusion approximation is investigated. In this theoretical model, diffusion coefficient D of the standard diffusion approximation is substituted by diffusion coefficient Dasym of P3 approximation. Analytic solution RHybrid(ρ) of this hybrid diffusion for reflectance in single source approximation and steady-state case with extrapolated boundary is obtained; influences of the transport albedo a′ on the standard diffusion approximation RDA(ρ) and the hybrid diffusion approximation RHybrid(ρ) are compared; recovering of optical parameters from diffuse reflectance RHybrid(ρ) is demonstrated, and the errors and application ranges are studied. The results show that this hybrid diffusion approximation RHybrid(ρ) can be used in strong absorption media and at short source-detector separation.
Geometric phase evolution of atom under non-Markovian environment
Authors: Zheng Li-Ming  , Liu Song-Hao  , Wang Fa-Qiang  ,   (1)华南师范大学信息光电子科技学院，广州  510006; (2)暨南大学信息科学技术学院，广州  510632
Published: December 2020

The geometric phase of two-level atom, under the non-Markovian effect of environment, is investigated from the microscopic Hamiltonian. The results show that the geometric phase of atom strongly coupled with cavity field is larger than that of atom weakly coupled with cavity field, and the difference between them becomes larger as the loss of environment increases. In the case of relatively small environment loss, the geometric phase of atom shows continuous or discontinuous evolution with time depending on different initial atom states, and the discontinuity range increases when the environment loss increases. In a word, the geometric phase exhibits complicated characteristics under non-Markovian environment.
Simultaneous all-optical individual channel clock extraction and wavelength conversion using an optically injected Fabry-Perot laser diode
Authors: Lü Yu-Xiang  , Sun Shuai  , Yang Xing  ,   太原理工大学理学院物理系，太原  030024
Published: December 2020

We propose and demonstrate a novel technique that uses a FabryPerot laser diode （FPLD） to perform simultaneous alloptical individual channel clock extraction and wavelength conversion. The nonlinear dynamical period1 oscillation can occur when a semiconductor laser is optically injected. By utilizing the crossgain modulation effect and the period1 oscillation harmonic frequencylocked in an optically injected semiconductor laser, we can extract the wavelength conversional individual channel optical clock from the opticaltimedivisionmultiplexing （OTDM） signal. In a FPLD, we numerically simulate the extraction of 20 GHz optical clock at 1550 nm from the 2×20 Gb/s OTDM signal at 1555 nm, and experimentally obtain the -105 dBc/Hz phase noise frequency division clock of 1236 GHz to 618 GHz with simultaneous wavelength conversion from 155024 nm to 154591 nm. Moreover, we investigate the influence of the injection optical power level, wavelength detuning, the FPLD's bias current level and the longitudinal mode selection on the optical clock extraction. This method is potential to technologically apply in the alloptical demultiplexing and wavelength routing in the OTDM mixed wavelengthdivisionmultiplexing （WDM） communication system.
Complete destructive interference of four partially coherent point sources
Authors: Cheng Ke  , Lü Bai-Da  ,   四川大学激光物理与化学研究所，成都  610064
Published: December 2020

By using the interference law for partially coherent light, the interference in a four-pinhole interferometer with square symmetry illuminated by partially coherent light is studied. It is found that the complete destructive interference in the four-pinhole interferometer may appear, and there may exist phase singularities of intensity and spectral degree of coherence. A comparison with the interference of two and three partially coherent point sources is made and the results can be physically interpreted in such a way, that in spite of the partial coherence of four point sources, the sum of the fields emerging from two point sources may be fully correlated with the sum of the fields emerging from the other two point sources.
Influence of cavity wall elasticity on resonant frequency of small underwater cylindrical Helmholtz resonator
Authors: Wang Ze-Feng  , Hu Yong-Ming  , Luo Hong  , Meng Zhou  , Ni Ming  , Xiong Shui-Dong  ,   国防科学技术大学光电科学与工程学院，长沙  410073
Published: December 2020

Influence of cavity wall elasticity on resonant frequency of small underwater cylindrical Helmholtz resonator is studied theoretically and experimental. Based on the theory of electroacoustic analogy, the simplified low frequency lumpedparameter model of the Helmholtz resonator is constructed. A general, convenient for calculation expression of the resonant frequency is given by circuit analysis. The influence of the thickness and the material of the resonator on the resonant frequency is investigated by numerical method. And the approximate rigid conditions for small underwater cylindrical Helmholtz resonators of different sizes are given. Small cylindrical Helmholtz resonators of different wall thickness and material were tested in a standingwave tube filled with water. Experimental results well testified the theoreticl results and the approximate rigid condition. This paper is useful for the design and application of the underwater cylindrical Helmholtz resonators.
The surface energy and nano-adhesion behavior of some micro-component material in MEMS
Authors: Xue Wei  , Xie Guo-Xin  , Wang Quan  , Zhang Miao  , Zheng Bei-Rong  ,   (1)清华大学摩擦学国家重点实验室，北京  100084; (2)温州大学机电工程学院,温州  323035; (3)中国科学院上海微系统与信息技术研究所传感技术国家重点实验室，上海  200050
Published: December 2020

This paper compares and discusses the surface energy and its related factors between different kinds of micro-component materials commonly used in MEMS, and analyzes the nano-adhesion behaviors of their surfaces. The results by the Owens method show that the surface energies of the silicon-based materials are between 60—75 mJ/m2 and the presence of surface roughness would result in higher nominal surface energy when the contact angle is less than 90°. In contrast, the nominal surface energy would go much lower when the surface is rough with the coverage of a SAM film. There is a certain dependence of nano-adhesion on surface energy, and the effect of surface roughness on nano-adhesion can be neglected in the present study.
Mathematical analysis of pool boiling heat transfer
Authors: Xiao Bo-Qi  , Chen Ling-Xia  , Jiang Guo-Ping  , Rao Lian-Zhou  , Wang Zong-Chi  , Wei Mao-Jin  ,   (1)广州大学工程抗震中心，广州  510405; (2)三明学院物理与机电工程系，三明  365004
Published: December 2020

In this paper for the mechanisms of pool boiling heat transfer a mathematical model is derived based on statistical treatment. No additional new empirical constant is introduced. The proposed model for pool boiling heat flux is found to be a function of wall superheating, minimum and maximum active cavity sizes, the contact angle, and physical properties of fluid. It also turns out that the present model well explains the mechanism of how wettability affects the boiling heat flux. The model predictions are compared with the existing experimental data, and fair agreement is found for different contact angles.
Defect structures of Rayleigh-Benard travelling wave convection in binary fluid mixtures
Authors: Ning Li-Zhong  , Qi Xin  , Yu Li  , Zhou Yang  ,   (1)西安理工大学水利水电学院，西安  710048; (2)西安理工大学水利水电学院，西安  710048；重庆水利电力职业技术学院，重庆  402160
Published: December 2020

By using a twodimensional numerical simulation of the fully hydrodynamic equations, the dynamics of the traveling wave convection in binary fluid mixtures with defects was studied. For the separation ratio Ψ=-06, the system changes from localized traveling wave to traveling wave （TW） convection with the defects with increasing reduced Rayleigh number r. Then, the defects disappear and it changes to TW without defects with further increasing r. For different separation ratio Ψ, the periodicity of appearance of defects increases with reducing separation ratio and increasing r. The increase rate for a small negative separation ratio is larger than that for separation ratios. The range of existence of defects Δr remarkably decreases with the absolute value of Ψ. At Ψ=-011, the defects are annihilated and the TW with defects is not found. The system turns to the TW without defects from the TW with defects where r is larger than the upper limit of Δr. However, different values of Ψ correspond to different TW patterns when r is less than the lower limit of Δr. Therefore, it is obvious that the Ψ has influence on the pattern formation and on the transition between the patterns, and the transition between the patterns is also complex.
Neutron diffraction study of stress and lattice mismatch induced by thermo-mechanical fatigue in single crystal superalloys
Authors: Sun Guang-Ai  , Darren Hughes  , Thilo Pirling  , Vincent Ji  , Chen Bo  , Chen Hua  , Wu Er-Dong  , Zhang Jun  ,   (1)巴黎第十一大学奥赛分子化学与材料学院，巴黎  91405; (2)法国劳厄-朗之万研究所，格勒诺贝尔  38042; (3)四川大学原子与分子物理研究所，成都  610065；中国工程物理研究院核物理与化学研究所，绵阳  621900; (4)中国工程物理研究院核物理与化学研究所，绵阳  621900; (5)中国科学院金属研究所材料科学国家实验室，沈阳  110016
Published: December 2020

The center points of the thermomechanical fatigued single crystal Nibased superalloys were measured by neutron diffraction and the results have been treated in two methods: two overlapped peaks and a single peak. The macroscopic equivalent stress, deviatoric stress components, γ/γ′ phase equivalent stress and lattice mismatch are determined according to the experimental results. The stress results show that the macroscopic equivalent stresses are basically consistent when using two analysis methods, the maximum of macroscopic equivalent stress and deviatoric stress components appeared at thermomechanical fatigue that of 100 cycles, and at this point, the microdefects， such as dislocations, are saturated and the stress of γ′ phase away from the center was reduced remarkably. The calculated results also indicate that the negative lattice mismatch is reduce markedly at the beginning of the thermomechanical fatigue. Subsequently, it increases linearly with the fatigue cycles at the speed 81×10-6 per cycle because of the accumulated plastic strain in the matrix.
Synthesis and growth mechanism study of SnO2 micro/nanomaterials
Authors: Jia Xi  , Liu Ai-Ping  , Liu Yang-Yi  , Tang Wei-Hua  , Wang Jun-Wei  ,   浙江理工大学光电材料与器件中心，杭州  310018
Published: December 2020

Using Sn powders as source material, different SnO2 nanostructures, such as nanowires and nanorods, nanoflowers were synthesized successfully by simple chemical vapor deposition in a low temperature. SnO2 submicron rings were obtained by reducing the oxygen gas concentration in carrier gas and the effect of oxygen gas on controlling the morphology of products was demonstrated by adjusting the quantity of Sn powders and the rate of heating. The products were characterized by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectrometry. The growth mechanism of the products was further discussed.
Effects of vacancy structural defects on the elastic properties of carbon nanotubes
Authors: Yuan Jian-Hui  , Cheng Yu-Min  , Zhang Zhen-Hua  ,   (1)长沙理工大学物理与电子科学学院,长沙  410076; (2)上海大学上海市应用数学和力学研究所,上海  200072
Published: December 2020

The molecular dynamics method is used in this paper to investigate the effect of vacancy defects on the elastic properties of armchair and zigzag singlewalled carbon nanotubes （SWCNTs）.The results show that the Young's moduli of armchair （5,5）, （10,10） and zigzag （9,0）, （18,0） singlewalled carbon nanotubes are 948, 901 GPa, and 804, 860 GPa,respectively. The armchair and the zigzag SWCNTs Young's moduli decrease and increase with the increase of the nanotubes' diameter, respectively. With the increase of the vacancy defect ratio, the Young's moduli will decrease. When the vacancy defect achieves a certain ratio, there appears a sudden slowdown in the curves of Young's modulus vs. vacancy defect ratio and a platform emerges. The influence of the bivacancy defects on the Young's moduli of the carbon nanotubes depends on the orientation of the defects. As the number of atoms between the two singlevacancy defects increases, when the defects are located in the direction of the axis, the Young's modulus decreases to certain value and fluctuates around it; but when the defects are located in the direction of the circumference, the Young's modulus decreases first, then ascends and finally tends to a constant, and the Young's moduli will decrease a little with increasing of the distance between the two singlevacancies. The reasons are analyzed by considering the features of the bond σ and bond π between the molecules and the theory of the shortrange coupling of the electron clouds between two defects as well as the theory of 51DB defect formation in the vacancy defects.
Transverse optical trapping force of absorbing double-layer spherical particles in a Gaussian beam
Authors: Zhang Yan-Feng  , Li Yu-Dong  , Zhao Li-Hua  , Liu Hong-Bing  , Chen Jing  , Cui Guo-Xin  , Xu Jing-Jun  , Sun Qian  ,   (1)教育部弱光非线性光学重点实验室，南开大学,天津  300457; (2)教育部弱光非线性光学重点实验室，南开大学,天津  300457；天津市光子学材料与技术重点实验室，南开大学，天津  300071; (3)教育部弱光非线性光学重点实验室，南开大学,天津  300457；中欧工程师学院，中国民航大学，天津  300300
Published: December 2020

In this paper, the transverse optical trapping of absorbing double-layer spherical particle is studied based on geometrical optics model. A model for double-layer spherical particle with optical absorption is presented. The transverse optical trapping force of a double-layer dielectric spherical particle with linear absorption in the outer layer illuminated by a focused Gaussian beam of TEM00 mode is simulated numerically. Our results show that the characteristicsof optical trapping, including the stable trapped positions, the peak intensityand the stiffness of stable trapping, greatly depend on by the absorption coefficient of the double-layer spherical particle. Besides, the ratio of the inner radius to the outer radius of the particle also has modulating influence on the properties of transverse trapping. It is possible to trap transversely the double-layer spherical particle with absorption on the axis of the incident Gaussian beam and on a circle centered at the optical axis for different axial offsets of sphere center from the beam waist as well.
Study of ultraviolet photoluminescence from SiC nanorods
Authors: Jin Hua  , An Li-Nan  , Bu Fan-Liang  , Li Li-Hua  , Wang Rong  , Yang Wei-You  , Zhang Li-Gong  ,   (1)清华大学材料科学与工程系，北京  100083; (2)中国科学院长春光学精密机械与物理研究所激发态物理重点实验室,长春  130033; (3)中国人民公安大学安全防范系，北京  102416
Published: December 2020

Silicon carbide （SiC） nanorods were synthesized via catalyst-assistant crystallization of amorphous silicon carbonitride. An intensive sharp photoluminescence peak at 378 nm was observed from the SiC nanorods. SEM, TEM, HRTEM and XRD was used to characterize the structure. XRD pattern showed that the nanorods are pure 3C-SiC containing stacking faults. The HRTEM image showed that the stacking faults were threefold stacking faults, which resembled the structure of 6H-SiC. We attribute the emission to these stacking faults, and discussed the emission mechanism.
Preparation and optical properties of Cu nanowire in mica template
Authors: Mo Dan  , Chen Yan-Feng  , Duan Jing-Lai  , Hou Ming-Dong  , Liu Jie  , Sun You-Mei  , Xue Zhi-Hao  , Yao Hui-Jun  , Zhang Ling  ,   (1)中国科学院近代物理研究所，兰州  730000; (2)中国科学院近代物理研究所，兰州  730000；中国科学院研究生院，北京  100049
Published: December 2020

Nanopores with diameters between 30 nm and 180 nm have been fabricated by inducing latent track with fast heavy ions and etching process in 25 μm thick, singlecrystal muscovite mica. For short etching time, the nanopores are columns with circular cross section. For long etching time the cross section of nanopores becomes rhombic. Thus the shape of nanopores depends on the etching time. Cu nanowires have been fabricated with controlled dimensions by electrodeposition into the nanopores. The ultravioletvisible light absorption spectra of Cu nanowires embedded in mica templates show that the circular Cu nanowires with diameter smaller than 60 nm exhibit one intense resonance peak and one smaller peak. With increasing diameter of the nanowires， the intense peak is redshifted while the smaller peak strengthens gradually. The diameter and shape can tune the optical properties of Cu nanowires. The morphology and crystallinity of the Cu nanowires were studied by means of scanning electron microscopy and Xray diffraction.
Theoretical modeling of microscopic photothermal expansion and experimental study of photothermal microactuators
Authors: Liu Chao  , Zhang Dong-Xian  , Zhang Hai-Jun  ,   浙江大学现代光学仪器国家重点实验室，杭州  310027
Published: December 2020

A novel photothermal microactuator based on microscopic photothermal expansion is developed. A theoretical model of photothermal expansion for photothermal microactuator is established. Using finite element analysis and numerical method, the expressions of the temperature distribution and the linear thermal expansion are deduced. A photothermal microactuator of 1200?μm length is fabricated by using an excimer laser micromachining system. According to the parameters of the laser and the photothermal microactuator, a theoretical relationship between the expansion and the laser power is calculated. The results indicate that the photothermal microactuator deflection （corresponding to expansion） is approximately linear with the laser power irradiating the expansion arm, according with theoretical predictions quite well. As an application, a Biswitch like photothermal microactuator is built and the successful photothermal microactuation experiment shows the Biswitch function can be realized.
A novel interconnect crosstalk RLC analytic model based on the nanometer CMOS technology
Authors: Zhu Zhang-Ming  , Qian Li-Bo  , Yang Yin-Tang  ,   西安电子科技大学微电子研究所,西安  710071
Published: December 2020

Based on the nanometer CMOS technology, a novel parallel RLC coupling interconnect analytic model is presented. Based on the function approach and reduced order techniques, an analyzable expression for the outlying terminal of the disturbed line is derived by the model in the off-angle step input signal. In the 90 nm and 65 nm CMOS process, the proposed RLC coupling interconnect analytic model enables to estimate the crosstalk voltage within 4% errors compared with Hspice simulation for various interconnect coupling size. The proposed analytic model can be applied to the design of nanometer SOC and optimizing the design for VLSIs.
Molecular dynamics simulation of heterogeneous adatom diffusion on Cu（001） surface
Authors: Meng Li-Juan  , Li Rong-Wu  , Liu Shao-Jun  , Sun Jun-Dong  ,   (1)北京师范大学物理学系，北京  100875; (2)北京师范大学物理学系，北京  100875；宿迁学院基础部，宿迁  223800
Published: December 2020

The diffusion processes of single adatoms Ag,Pd and Cu on Cu（001） surface are investigated by molecular dynamics. By observing the mechanisms of selfdiffusion and heterogeneous diffusion, the diffusion frequencies of three kinds of adatoms under different temperatures are counted and diffusion barriers and the preexponential factors of diffusion frequency are fitted. The results of diffusion barriers are compared with those from the static calculation. The results show that: Under 800 K, the dominant diffusion mechanism of adatom Ag,Pd and Cu is the simple hopping mechanism. The hopping frequency of adatom Ag is the biggest, and that of adatom Pd is the smallest. For homogeneous and heterogeneous adatom diffusion processes, the relationship between diffusion frequency and temperature obeys the Arrhenius formula. The diffusion barriers fitted from Arrhenius formula are relevant to the surface structure and the cohesive energy of adatom on the surface. The transition temperatures of diffusion from the jumpmechanismdominant to the exchangemechanismdominant are about 825 K and 937 K for Pd and Cu adatoms respectively.
Crystallization of Si3N4 on h-AlN and superhardness effect of AlN/Si3N4 nanomultilayers
Authors: Wu Xiao-Yan  , Kong Ming  , Li Ge-Yang  , Zhao Wen-Ji  ,   上海交通大学金属基复合材料国家重点实验室，上海  200240
Published: December 2020

A series of AlN/Si3N4 multilayers with different Si3N4 thickness were synthesized by reactive magnetic sputtering. The microsructure of the multilayers was characterized with Xray diffraction and highresolution transmission electron microscopy, and nanoindentation was employed to measure their mechanical properties. The crystallization behavior of Si3N4 modulation layer in the multilayers and its influences on the microstructure and mechanical properties of AlN/Si3N4 multilayers were studied. The results show that when Si3N4 thickness is less than about 1 nm, Si3N4, normally amorphous in deposition state, could form a wurtzitetype pseduocrystal structure, same as the structure of hAlN, due to the template effect of AlN crystal layer. Crystallized Si3N4 layers and AlN template layers grow coherently into columnar crystals. Correspondingly, the hardness of the films is enhanced, showing a superhardness effect. Further increasing the thickness of Si3N4 layers, the coherent interfaces of the multilayers are damaged and Si3N4 layers become amorphous, accompanied by the decline in hardness of the films. The discussion indicates that the superhardness effect in AlN/Si3N4 nanomultilayers is related to the enhancement of modulus difference between the two different module layers caused by the alternating stress field in the coherent growth structure.
The evolution of the structure and electronic properties of the fullerene derivatives C60（CF3）n(n=2, 4, 6, 10): A density functional calculation
Authors: Tang Chun-Mei  , Chen Xuan  , Deng Kai-Ming  , Hu Feng-Lan  , Huang De-Cai  , Xia Hai-Yan  ,   (1)南京理工大学应用物理系,南京  210094; (2)南京理工大学应用物理系,南京  210094；济宁学院物理系，济宁  273155
Published: December 2020

The generalized gradient approximation （GGA） based on density functional theory （DFT） is used to analyze the evolution of the structure and electronic properties of the fullerene derivatives C60（CF3）n （n=2, 4, 6, 10）. It is found that among the three respective possible stable isomers of C60（CF3）4 and C60（CF3）6, the structure C60（CF3）4 with ppp addition and C60（CF3）6 with pppmp addition are the most stable structures, respectively. By analyzing the structures of C60（CF3）2, C60（CF3）41，C60（CF3）61, and C60（CF3）10, it was found that both the average C—C bond length and the CC60—CCF3 bond length increase with the increase of the CF3 number. It was found from the electronic properties of four compounds that the heat of reaction of the compounds almost linearly increases with the number of the CF3, and its maximum appears at n=6, thus, C60（CF3）6 should be the most easily synthesized derivative. It is known from the Mulliken charge that the interaction between CF3 and the cage and the electron transference from CF3 to the cage increase with the number of the CF3 However, the net spins of the compounds are all zero, indicative of their closedshell electronic structures. Finally, the frontier orbital analysis shows that the electron detaching and attaching both occur at carbon sites of the cage.
First-principles calculation of p-Zn1-xMgxO electronic structure by doping with Al and N
Authors: Liu Qiang  , Cheng Xin-Lu  , Fan Yong-Heng  , Yang Xiang-Dong  ,   (1)四川大学原子与分子物理研究所，成都  610065; (2)四川大学原子与分子物理研究所，成都  610065；重庆工学院数理学院，重庆  400054; (3)中国工程物理研究院激光聚变研究中心，绵阳  621900
Published: December 2020

The first principles calculation of plane wave ultra-soft pseu-dopotential method based upon the denstiy functional theory and generalized gradient approximation have been adopted to investigate the energy band structure and electronic density of states and Mulilken charge population of Al and N codoped Zn1-xMgxO. The calculation indicates that the Al and N codoped Zn1-xMgxO has the trend of forming p-type Zn1-xMgxO.
Exact solutions to the transportation of electrons through equilateral polygonal quantum rings with Rashba spin-orbit interaction
Authors: Li Peng  , Deng Wen-Ji  ,   华南理工大学物理系，广州  510641
Published: December 2020

The quantum transportation of electron through equilateral polygonal quantum rings with Rashba spin-orbit interaction is studied. By using the typical method of quantum network and the Landauer-Büttiker formalism, we solve analytically the scattering problem of electron through any equilateral polygonal quantum ring, and obtain the relevant formula for spin transportation conductance. The characters of conductance varying with wave-vector of electron and the strength of spin-orbit interaction are investigated, and the series of zero conductance points originating from spin-orbit interaction is determined. In the limit of infinite number of borders of equilateral polygon, we prove that the formula is consistent with the results obtained directly from the circular model of quantum rings.
Giant Fano interference in a T-shaped coupled quantum-dot mesoscopic A-B ring
Authors: Chen Xiong-Wen  , Chen Bao-Ju  , Shi Zhen-Gang  , Song Ke-Hui  ,   (1)怀化学院物理与电子信息科学系,怀化  418008; (2)怀化学院物理与电子信息科学系,怀化  418008；怀化学院信息科学研究所,怀化   418008
Published: December 2020

Using the slave-boson mean-field approximation, we theoretically study the properties of the ground state of T-shaped-coupled quantum-dot Aharonov-Bohm （A-B） ring in the Kondo regime by means of one impurity Anderson Hamiltonian. It is found that in this system, the complex physical properties are determined by the interplay of the Kondo-Fano effect. When the free electron spin of quantum dot embedded in A-B ring is screened, with the increase of coupling between the dots, a giant increasing sharp persistent current （PC） peak appears, which implies that a giant Fano interference exists in this system. But, in this case, the Kondo PC peak is not affected. Thus this model may be a new candidate Kondo screening cloud.
Effects of gradient disorder on persistent currents in two-dimensional mesoscopic rings
Authors: Ma Ming-Ming  , Chen Hong-Bo  , Ding Jian-Wen  , Xu Ning  ,   湘潭大学物理系，纳米物理与稀土发光研究所,湘潭  411105
Published: December 2020

Taking into account the gradient decay of the real disorder, we explore the effects of the disorder gradient and the structure sizes on persistent currents in the disorderorder twodimensional mesoscopic ring system, within the tightbinding model. In the absence of disorder gradient, the persistent current firstly decreases and then increases with disorder strength, indicating a localizedballisticlike transition existing there. In the presence of disorder gradient, the persistent current is decreased, due to the stronger disorder scattering in the surface disorder region of lower disorder strength. In the case of exponentially decaying disorder, especially, the localizedballisticlike transition disappeared, meaning that its observability depends on the distribution of the gradient disorder. In addition, the effects of both the ring width and the penetration depth of the disorder on persistent currents are explored, showing a strange quantum sizeeffect, which is different from previous results.
Fabrication and optical properties of functional optical silver nano-films
Authors: Huang Qian  , Cao Li-Ran  , Geng Wei-Dong  , Sun Jian  , Wang Shuo  , Xiong Shao-Zhen  , Zhang Xiao-Dan  , Zhao Ying  ,   南开大学光电子薄膜器件与技术研究所，光电信息技术科学教育部重点实验室，光电子薄膜器件与技术天津市重点实验室，天津  300071
Published: December 2020

Silver nano-films were prepared by thermal evaporation. Scanning electron microscope observations showed that the silver films have nano-structures in morphology. The optical properties of silver nano-structures were obtained by ultraviolet-visible spectrometry, which shows the resonance wavelength of surface plasmon. Precise control of thermal deposition parameters allows the fabrication of silver films on glass substrates with tunable surface plasmon resonance wavelength, which makes the films to have tunable optical properties of transmittance and reflection. In this work, we have prepared silver nano-films with over 90% transmittance in the near-IR region and near 50% reflection in the visible region near the surface plasmon resonance wavelength. Due to the novel optical properties, silver nano-films have an enormous light management potential for use as an interlayer in thin-film solar cells.
Improvement on the classical model for new domain nucleation in ferroelectrics
Authors: Zhou Bo  , Chen Yun-Lin  , Liu Gang  , Zhan He  ,   (1)北京交通大学理学院，北京  100044; (2)南开大学物理科学学院，天津  300071
Published: December 2020

The new-domain nucleation by applying a weak electric field is an important process for the ferroelectric domain inversion in ferroelectrics. We studied the process of the new-domain nucleation in ferroelectrics using the classical model, and found that the rate of nucleation in the electric field did not agree with the experimental result. Based on Tagantsevs model, we improved the classical model of the new-domain nucleation using a long flat dagger model instead of the ellipse model. Using the improved model, the result of the theoretical calculation agreed well with the experimental measurement.
Analysis of the spectral properties of Er3+:Y2O3 upconversion materials
Authors: Zhang Shuan-Qin  , Lu Yan-Li  , Shi Yun-Long  ,   (1)山西大同大学固体物理研究所,大同  037009; (2)山西大同大学固体物理研究所,大同  037009；总装备部工程兵技术装备研究所，无锡  214035; (3)总装备部工程兵技术装备研究所，无锡  214035
Published: December 2020

Rare earth doped yttrium oxide （RE3+:Y2O3） nano powder was fabricated by wet chemical method. The influence of doping concentration and different doping elements on the microstructure, phase composition and spectral properties was analyzed. It was shown that by changing the doping element and doping concentration, the spectral properties, including spectral coefficients and upconversion spectrum, can be controlled, and the material can be made to have better absorption properties for 106 μm laser light.
A novel method to estimate the parameters of 1/f noise of semiconductor laser diodes
Authors: Zhang Zhen-Guo  , Gao Feng-Li  , Guo Shu-Xu  , Li Xue-Yan  , Yu Si-Yao  ,   吉林大学电子科学与工程学院，长春  130012
Published: December 2020

The variable relation of the coefficient variance of wavelet transformation of 1/f fractal signal in white noise versus the scale is adequnately modified to develop a novel method based on least\|squares to estimate the parameters of 1/f noise of semiconductor laser diodes （LDs）. The measured data indicate that this method can effectively extract the 1/f noise submerged in white noise of LDs, and the estimated 1/f signal is in better accordance with the measured results of the contrast apparatus.
The temperature-dependent optical properties of ZnO film deposited on sapphire fiber-ending
Authors: Sui Cheng-Hua  , Cai Ping-Gen  , Chen Nai-Bo  , Wei Gao-Yao  , Xu Xiao-Jun  , Zhou Hong  ,   (1)浙江工业大学应用物理系，杭州  310032; (2)浙江工业大学之江学院理学系，杭州  310024
Published: December 2020

In this paper, ZnO thin film was first grown on the sapphire fiber-ending by electron-beam evaporation, which has good morphology and high crystallization quality. The transmittance spectra showed that the sharp optical absorption edge has a red shift with increasing temperature, and the obtained temperature-dependent band gap energy for ZnO follows to the linear relation Eg（T）=340-491×１０-4T. This formula presents the key to fabricate new broad\|measurement range fiber-optic temperature sensors based on semiconductor ZnO by utilizing the optical absorption spectra at different temperatures.