bluuebunny/crossref_metadata_2025 huggingface dataset:
Label-free and real-time detection of interactional dynamic processes of rabbit IgG with different concentrations and goat anti-rabbit IgG by oblique-incidence reflectivity difference method
Authors: He Li-Ping  , Sun Yue  , Dai Jun  , Wang Jing-Yi  , Lü Hui-Bin  , Wang Shu-Fang  , Jin Kui-Juan  , Zhou Yue-Liang  , Yang Guo-Zhen  ,   College of Physics Science and Technology, Hebei University, Baoding 071002, China;,   Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Published: December 2020

We successfully label-free and real-time detecte the interactional dynamic processes of rabbit IgG with different concentrations (1.25 mg/mL, 2.50 mg/mL and 5.00 mg/mL), and goat anti-rabbit IgG with a concentration of 0.02 mg/mL by the oblique-incidence reflectivity difference method (OIRD). The dynamic curves and times of interaction, response to concentration of rabbit IgG, are obtained. The experimental results demonstrate that the OIRD method can not only can distinguish the biomolecular interactions, but also real-time detect the interactional dynamic processes of biomolecules, indicating that the OIRD method has promising and extensive applications for the investigating of biomolecular interactions.
Study of a gyrotron oscillator with corrugated interaction cavity
Authors: Han Yu  , Yuan Xue-Song  , Ma Chun-Yan  , Yan Yang  ,   School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China
Published: December 2020

Based on the nonlinear self-consistent theory and the three-dimensional electromagnetic simulation software CST, the beam-wave interaction of gyrotron with irregular cross section is studied. Through importing high frequency fields which are the results of CST, the beam-wave interaction efficiency, coupling coefficient and starting current can be obtained. In addition, a 0.4 THz third harmonic TE33 mode gyrotron with a corrugated interaction cavity is presented according to this approach. The gyrotron with a 40.5 kV/1 A electron beam, magnetic field of 5.09 T, and pitch factor of 1.5 can produce radiation with an output power of 3.3 kW.
Colloidal photonic crystal microstructure fiber:propagation characteristics analysis
Authors: Wu Jing  , Wang Ming  ,   Jiangsu Key Laboratory on Opto-Electronic Technology, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210046, China
Published: December 2020

In the paper, we describe the structure of colloidal photonic crystal microstructure fiber and investigate the propagation characteristics using the finite-difference time-domain method. A structure model is eastablished to simulate the transmission spectra and propagation field distributions under different wavelengths. Experimental system is built to measure the transmission spectrum of fabricated colloidal photonic crystal microstructure fiber. Experimental result is in good agreement with numerical result. The propagation field distribution result shows that the colloidal crystal changes the propagation mode of optical fiber under different wavelengths.
Code divided multiple access underwater acoustic communication based on active acoustic intensity average
Authors: Yin Jing-Wei  , Yang Sen  , Du Peng-Yu  , Yu Yun  , Chen Yang  ,   Science and Technology on Underwater Acoustic Laboratory, Harbin Engineering University, Harbin 150001, China
Published: December 2020

Code divided multiple access (CDMA) underwater communication based on single vector sensor is studied in this paper. The most common methods to estimate azimuth with self-directivity of single vector sensor are average sound intensity method and complex sound intensity method, however, for the same frequency band multi-users, these methods are limited to the measurement of azimuths only for two users at the same time theoretically. An active average intensity method, which measures the azimuths of multi-users simultaneously with the excellent correlative characteristics of pseudo-random code in spread spectrum communication, is proposed in this paper. With the estimated azimuth, vector combination can be generated to adjust the directivity of vector sensor, achieve multi-user beam communication, inhibit multi-path interference, and enhance processing gain and lower error rate. Simulation and experiment for same frequency band spread spectrum multi-user communication testify the feasibility and utility of active average sound intensity method.
Numerical simulation of the spread of internal waves see from deep sea to shallow sea from the mixed model
Authors: Wang Jing  , Ma Rui-Ling  , Wang Long  , Meng Jun-Min  ,   College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China;,   First Institute of Oceanography, Qingdao 266061, China
Published: December 2020

From remote sensing images, it is found that the internal wave spreads from deep sea, by shelf slope, to shallow sea in the South Chinese sea. Because of the different environmental conditions and model applicabilities, it is the best to use two models to simulate the spread of ocean internal waves in deep or shallow sea. The spread of waves in deep sea is simulated with the nonlinear Schrdinger (NLS) equation first and then the spread of wave in shallow sea is simulated with the extended Korteweg de Vries (EKdV) equation by differential mathod. It can be found that the results are in good agreement with the actual remote sensing images, compared with those obtained by single model which consists of the NLS equation or the EKdV equation.
Effects of heterogeneous interfaces on microstructure and dielectric properties of Ca(Mg1/3Nb2/3)O3/CaTiO3 multilayered thin films
Authors: Zhou Jing  , Liu Cun-Jin  , Li Ru  , Chen Wen  ,   State Key Laboratory of Advanced Technology for Material Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
Published: December 2020

The effects of heterogeneous interfaces on the microstructure, the morphology and the dielectric properties of Ca(Mg1/3Nb2/3)O3/CaTiO3(CMN/CT) multilayered(ML) thin film prepared in the layer-by-layer mode with a certain thickness are investigated. According to the experimental results, an equivalent circuit of CMN/CT ML thin film is simulated, and the theoretical formulae of the dielectric constant and loss of thin film are established. The results indicate that CMN/CT ML thin film, in which CT and CMN phases can exist independently, possesses a pure orthorhombic perovskite structure, dense smooth surfaces and intermediate layers at the heterogeneous interfaces, and that the dielectric constant increases and the dielectric loss decreases with the increase in the number of heterogeneous interfaces, and reducing the thickness of the interfacial transition layer is useful to improve the dielectric properties of CMN/CT multilayered thin film.
Hydrogen storage capacity of Y-coated Si@Al12 clusters
Authors: Huang Hai-Shen  , Wang Xiao-Man  , Zhao Dong-Qiu  , Wu Liang-Fu  , Huang Xiao-Wei  , Li Yun-Cai  ,   (Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, China;,   Department of Basic Course, Haikou College of Economics, Haikou 571127, China
Published: December 2020

The adsorption property of hydrogen molecules on YmSi@Al12 (m=13) cluster is investigated using the density functional theory. The results show that yttrium atoms do not suffer from clustering on the Si@Al12 cluster. The 18-electron rule can be used to design these systems, and Si@Al12 cluster coated with three yttrium atoms can adsorb 16 H2 molecules with a gravimetric density of up to 5.0 wt%. The calculated adsorption energy of 0.324-0.527 eV/H2 molecule is suited for reversible hydrogen storage in near-ambient conditions.
Moment method for strain analysis and its application in molecular dynamics
Authors: Lu Guo  , Wang Shuai-Chuang  , Zhang Guang-Cai  , Xu Ai-Guo  ,   Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
Published: December 2020

It is necessary to investigate the characteristics and the evolution law of metal deformation by using the appropriate strain analysis method. The deformation of metal is complex, so there exists no useful method to amalyze the local deformation characteristics and to describe the global equivalent deformation of deformed metal. In this paper, we propose a statistical moment method of strain analysis. Statistical moment method builds up the relationship between micro quantities and macro strain. For instance, it is used to study the deformations of monocrystal under uniaxial load and the nanocrystalline under shear and shock, showing that moment method can not only describe and evaluate the local and the global deformation of metal but also distinguish elastic and plastic deformation by nonuniform coefficient. Moment method is a general and effective way to investigate the deformation mechanism of complex structure material.
Theoretical analysis on scanning spectral filter method for signal-noise-ratio improvment in femtosecond laser system
Authors: Ma Aai-Ru  , Sui Zhan  , Feng Guo-Ying  , Sun Nian-Chun  , Wang Yi-Shan  , Zhang Bin  , Chen Jian-Guo  ,   College of Physics and Chemistry, Xihua University, Chengdu 610064, China;,   College of Electronics Information, Sichuan University, Chengdu 610064, China;,   Research Center of Laser Fusion CAEP, Mianyang 621900, China;,   Xi’an Institute of Optics and precision Mechanics, state Key Laboratory of Transient Optics and Photonics, Xian 710119, China
Published: December 2020

A scanning spectral filter method to improve the signal-noise-ratio in the femtosecond chains is proposed by using the characteristic that the instantaneous frequency varies with the time approximately linearly for the chirped pulse in the time-frequency domain. The scanning spectral filtering for reduing the amplification of spontaneous emission (ASE) intensity is analyzed in the time-frequency domain by using the Short-Time Fourier Transform method. The results show that the pulse contrast can be improved by two orders, and the transmission efficiency of the chirped pulse can exceed 90% when the synchronizing time jitter ranges from -2ps to 2ps and the chirp rate p from 0.9C/T2 to 1.10C/T2. Adopting the cascaded scanning filter to improve the pulse contrast is investigated too, which can improve the pulse contrast effectively. The great advantage of this novel nonlinear spectral filter technology is high energy and high peak intensity femtosecond chains for it filters out the ASE in the near field in temporal domain.
X-ray source generation under laser-Ar cluster interaction
Authors: Sun Yan-Qian  , Chen Li-Ming  , Zhang Lu  , Mao Jing-Yi  , Liu Feng  , Li Da-Zhang  , Liu Cheng  , Li Wei-Chang  , Wang Zhao-Hua  , Li Ying-Jun  , Wei Zhi-Yi  , Zhang Jie  ,   Key Laboratory of Optical physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;,   State Key Laboratory of Geomechanics and Deep Underground Engineering, School of Science, China University of Mining and Technology, Beijing 100083, China;,   Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;,   Northwest Institute of Nuclear Technology, Xi’an 710024, China;,   Department of Physics, Shanghai Jiaotong University, Shanghai 200240, China
Published: December 2020

BrightK-shell X-ray emissions are generated through the interaction between intense femtosecond laser pulses and Ar clusters. The total yield ofK-shell X-ray photons reaches 1 1011 photons/shot with a conversion efficiency of 2.8 10-5 in 4. When Ar clusters are irradiated by a laser pulse with intense prepulse, the yield ofK-shell X-ray photos will decrease due to prepulse ionization. Keeping high-density plasmas interacting with the main pulse is essential for obtaining the highest X-ray yield.
Research on the bidirectional reflectance of typical urban surface types measured by the directional polarimetric camera
Authors: Xie Dong-Hai  , Gu Xing-Fa  , Cheng Tian-Hai  , Yu Tao  , Li Zheng-Qiang  , Chen Xing-Feng  , Chen Hao  , Guo Jing  ,   State Key Laboratory of Remote Sensing, Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 100101, China;,   Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

This paper deals with the retrieving of the bidirectional reflectance distribution functions (BRDFs) of the distinct urban cover in the Pearl River Delta (PRD) region employing the high-spatial-resolution multi-angle polarized measurements made by the directional polarimetric camera (DPC). The results show that three BRDF models (RPV, Ross-Roujean and Ross-Li) describe the DPC measurements well. Forest is best fitted by Ross-Li and bare soil is best fitted by Ross-Roujean. Urban and shrub are best fitted by RPV. The results demonstrate that the reflectances of different types of surfaces are different and increase with the increase of scattering angle. The basic theory of investigating surface properties using multi-angle measurements is proposed.
Effects of doping concentration and sintering temperature on luminescence of CaWO4:Eu3+ phosphor
Authors: Gao Yang  , Lü Qiang  , Wang Yang  , Liu Zhan-Bo  ,   College of Physics and Electronic Engineering, Mudanjiang Normal University, Mudanjiang 157012, China;,   Mudanjiang Medical University, Mudanjiang 157011, China;,   Heilongjiang Key Laboratory of Cancer Prevention and Treatment, Mudanjiang Medical University, Mudanjiang 157011, China
Published: December 2020

The CaWO4:Eu3+ phosphors with different doping concentrations and different sintered temperatures are synthesized using the microemulsion reaction method. After sintered at different temperatures, the samples with doping concentration of 30 or 50 mol% can obtain the brightest characteristic emissions from Eu3+ ions. At 800 ℃, moreover, the samples with doping concentrations of 0.52 mol% can emit the strongest light. It is therefore concluded that more intense emissions enable the CaWO4:Eu3+ phosphors with high doping concentrations to have great potential to be used as efficient phosphors in the future.
A study on the cut-off amplification factor of the grid with film sphere and porous structure in grid- controlled electron gun
Authors: Li Fei  , Xiao Liu  , Liu Pu-Kun  , Yi Hong-Xia  , Wan Xiao-Sheng  ,   Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China;,   Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

Although the grid with film sphere and porous structure plays a very important role in sphere grid-controlled electron gun, its cut-off amplification factor can be obtained only in the plane-square-mesh approximation. Due to the lack of consideration for non-uniformity of cut-off amplification factor and information about cathode half-angle and radius of curvature of grid, the designs of sphere grid and electron gun cannot be related by the plane-square-mesh approximation, which is unusable as theory basis for fabricating thinner grid wires. In this paper, we model the grid with film sphere and porous structure and obtain the new expression for cut-off amplification factor by recalculating the screening factors and the ratios of the radius of grid wire to the area of this single mesh in different ring areas. In combination with the conclusion of cut-off amplification factor given in Spangenberg's book, the effects of grid wire's radius, sphere center angle and the number of radial grid wires on the cut-off amplification factor, and the variation of the cut-off amplification factor with temperature rising are obtained. Finally, the steps for the design of grid with film sphere and porous structure and some specific examples are presented. The results show that the grid devised by new expression is more stable and reliable, and problems existing in plane-square-mesh approximation are solved.
Investigation on the application of phase-attenuation duality to X-ray mixed contrast quantitative micro-tomography
Authors: Liu Hui-Qiang  , Ren Yu-Qi  , Zhou Guang-Zhao  , He You  , Xue Yan-Ling  , Xiao Ti-Qiao  ,   Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China;,   Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

Weak absorption is the main condition of conventional phase retrieval of in-line X-ray phase-contrast CT. The absorption of most samples, however, cannot be neglected in practice, it is needed to find new algorithms of attaining quantitative information. The phase retrieval algorithm of phase-attenuation duality (PAD) is used to realize the quantitative imaging of different density parts in a mixed contrast sample, and the digital simulation and experimental investigation are carried out in order to prove its feasibility in this paper. The simulated results show that the reconstructive errors of three materials are less than 1%, and the values decrease with the increase of refractive index. The experiment was carried out in the X-ray imaging and biological application beam-line of Shanghai Synchrotron Facility, and the results show that the PAD method can attain the sample quantitative information and the reconstructive accuracy is relatively low compared with that of simulation. Through the analysis of experimental data, ring artifact is mostly the primary cause. One single projection data set is used only in simulation and experiment. So the PAD approach can be applied to the quantitative information research of mixed contrast objects. In addition, because of the relatively low radiation dose, it should be suited to investigate the quantitative phase-contrast CT of biomedical sample with soft tissue and bone together.
Approximate functional variable separation for the porous medium equation with perturbed nonlinear source
Authors: Ji Fei-Yu  , Zhang Shun-Li  ,   Department of Mathematics, Northwest University, Xi'an 710069, China
Published: December 2020

The approximate functional variable separation for the porous medium equation with perturbed nonlinear source is studied. Complete classification of the perturbed equation which admits approximate functional separable solutions is obtained. The main solving procedure for the approximate functional variable separation approach is shown by way of examples, and the corresponding approximate functional separable solutions to the resulting equations are then constructed.
Isotropic negative permeability metamaterials and left-handed metamaterials based on miniature structure
Authors: Liu Ya-Hong  , Liu Hui  , Zhao Xiao-Peng  ,   School of Science, Northwestern Polytechnical University, Xi'an 710072, China
Published: December 2020

We propose an isotropic structure based on double split-ring resonator. We investigate experimentally and numerically the electromagnetic resonant properties of the proposed structure. The result shows that when the electromagnetic wave transmits in the directions parallel and perpendicular to the plane of the split ring resonator, respectively, the resonant bands having the negative permeability both arise at the same frequencies. However, when the electromagnetic wave transmits with oblique angle, the resonant characteristic is still unchanged. That is to say, resonant characteristic of the proposed structure is independent of incidence angle. This result indicates that the proposed structure is an isotropic medium. Combining the proposed double split-ring resonator structure with the wires, the left-handed metamaterial with negative refractive index can be obtained. In addition, the proposed structure has the merit of the miniaturization due to adding the metallic via-hole, which can increase the electric length of the structure. As a result, the resonant frequency of the structure shifts toward lower frequency greatly without increasing the dimension of the structure, and then the structure is still compact in the low frequency case. The introduction of the metallic via-hole can reduce the dimension of the structure by 50%. Therefore, the proposed structure will be a good candidate in the microwave applications such as antennas, filter, among others.
Research on the temporal-spatial distributions and the physical mechanisms for the sound speed profiles in north-central Indian Ocean
Authors: Li Jia  , Yang Kun-De  , Lei Bo  , He Zheng-Yao  ,   College of Marine, Northwestern Polytechnical University, Xi'an 710072, China
Published: December 2020

The structure of sound speed in ocean has a strong influence on underwater sound propagation. For underwater target detection and underwater acoustic communication, it is of great significance to obtain the temporal and spatial distribution of sound speed profile. Since the limitations and applicability of vertical grads method in structural analysis of sound speed in the Indian Ocean, optimal partition method is developed to calculate the sound spring layer. The study focuses on analysing the eigenvalues of sound speed profiles (SSPs) in the north-central Indian Ocean based on the last 10 year data of array for real-time geostrophic oceanography. The vertical structure characteristics of sound speed are investigated in the Indian Ocean, and the laws of temporal and spatial variation are obtained. The distribution of the fitting accuracy with the order of empirical orthogonal functions (EOF) are found. The physical mechanisms of the temporal and spatial variation of SSPs are revealed with the marine physical environment in Indian Ocean. The simulation results show that optimal partition method is suitable for the area to judge the structure of spring layer, and the parameters of the corresponding criterion is also proposed. The regional distributions of the fitting accuracy with the order of EOF are more obvious than with the seasonal variations. The deep channel axis exists at south 5S and there are three spring layers between 15S and 25S. The structures of SSPs in the Indian Ocean can be classified into four types: single spring layer, double spring layer type Ⅰ, double spring layer type Ⅱ and three spring layer, and for seasonal models: spring model, summer model, autumn model and winter model. The analysis results of the SSPs can provide some reference value for acoustic propagation and the sonar systems.
Free volume evolution of pre-annealed Zr55Al10Ni5Cu30 bulk metallic glass during rolling
Authors: Hu Yong  , Yan Hong-Hong  , Lin Tao  , Li Jin-Fu  , Zhou Yao-He  ,   State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, China;,   School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China
Published: December 2020

Traces of nanocrystals are introduced into Zr55Al10Ni5Cu30 bulk metallic glass through isothermally annealing the glass at 715 K for 30 min. The pre-annealed samples are rolled at different strain rates up to 95% thickness reduction at room temperature. The thermal stability and the free volume of the deformed sample are examined by differential scanning calorimetry. It is found that the thermal stability does not change with deformation degree. At any strain rate, free volume content increases continuously with the increase of deformation degree without saturation. As strain rate increases, however, the free volume content with the same deformation degree first increases and then decreases, which is significantly different from the case of the metallic glass with monolithic amorphous structure under plastic deformation.
Density functional study on the adsorption of C atoms on Ni (111) surface
Authors: Yuan Jian-Mei  , Hao Wen-Ping  , Li Shun-Hui  , Mao Yu-Liang  ,   Faculty of Mathematics and Computational Science, Xiangtan University, Xiangtan 411105, China;,   Faculty of Material, Photoelectronic and Physics, Xiangtan University, Xiangtan 411105, China
Published: December 2020

With the density functional first-principles calculations, we investigate the structures and electronic properties of transition metal nickel and its (111) surface. The adsorption behavior of single C atom on Ni (111) surface and its co-adsorption with the another C atom on Ni (111) surface are studied. The calculations on band structure and density of states show that significant spin polarization exists at the Fermi level of both nickel and its (111) surface. By comparing the adsorption energy, we find that the hollow site of hexagonal close-packed on the second layer of Ni atoms is the most stable position for the first C atom adsorption, and the hollow site of face-centered cubic on the third layer of Ni atoms is the most stable site for the co-adsorption of second C atom. Charge analysis shows that 1.566e charge transfers from each C atom to the adjacent Ni atom, which is similar to the 1.68e charge transfer in the first C atom adsorption case. The calculations on magnetism show that the magnetic moments of the two C atoms in co-adsorption are 0.059B and 0.060B, respectively, which are larger than the magnetic moment 0.017B of single C atom in Ni (111) surface.
Study on conducting characteristics of electrical trees in cross-linked polyethylene cable insulation
Authors: Chen Xiang-Rong  , Xu Yang  , Liu Ying  , Cao Xiao-Long  ,   State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China;,   Department of Materials and Manufacturing Technology, Chalmers University of Technology, Göteborg 41296, Sweden
Published: December 2020

The conducting characteristics of two typical electrical trees in cross-linked polyethylene (XLPE) cable insulation are studied by a combination of optical microscopy observation, partial discharge measurement and con-focal Raman spectroscopy analysis. Although they are grown under similar conditions, these two trees display very different shapes. One is a typical branch-pine tree grown at 9 kV, and the other is a branch tree grown at 11 kV. The growth and the partial discharge regularities show obvious differences. The disordered graphitic carbon is condensed in the main tree channels of the branch-pine tree. From the relative intensity of the graphitic carbon G band to D band, the graphitic domain is estimated to be about 8 nm in size. The tree channel resistance per unit length is less than 10 m-1, which is sufficient to prevent the partial discharge from developing within the tree structure. The branch-pine tree shows the features of the conducting tree. The fluorescence background is observed in the channels of branch tree, which shows the existence of the products of the material degradation, but no disordered graphitic carbon is observed in these tree channels. These tree channels display obvious non-conducting characteristics, which is not sufficient to prevent the continuous effect of the partial discharges. Finally, a single channel growth model is proposed for the conducting and non-conducting trees grown in XLPE cable insulation. Based on the equivalent circuit theory, the growth mechanisms of the two trees with different conducting characteristics in XLPE cable insulation are discussed.
The fabrication and field emission properties of ZnO nanoparticles-doped diamond-like carbon films by electrochemical deposition
Authors: Zhang Pei-Zeng  , Li Rui-Shan  , Xie Er-Qing  , Yang Hua  , Wang Xuan  , Wang Tao  , Feng You-Cai  ,   Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China;,   School of Science, Lanzhou University of Technology, Lanzhou 730050, China;,   Key Laboratory of Advanced Non-Ferrous Material of Gansu Province, Lanzhou University of Technology, Lanzhou 730050, China;,   College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, China
Published: December 2020

The formation of ZnO nanoparticles embedded in diamond-like carbon (DLC) thin film, deposited by electrochemical technique without post-processing, is observed. The effect of ZnO doping on the field emission (FE) property of DLC film is investigated. The chemical composition, the microstructure, and the surface morphologies of the sample are characterized by X-ray photoelectron microscopy, transmission electron microscopy, Raman spectrum, and atomic force microscope (AFM). It is shown that the ZnO nanoparticles are of a wurtzite structure and the content of ZnO increases with Zn source increasing in electrolyte. The ZnO doping enhances both the graphitization and the surface roughness of the DLC film, which is verified by Raman spectrum and AFM. By the ZnO doping, the FE properties of the DLC film are improved. An emission current density of 1 mA/cm2 is obtained at an electric field of 20.7 V/m for the film with a Zn/(Zn+C) ratio of 10.3at%. The improvement on the FE properties of the ZnO-doped DLC film is analyzed in the context of microstructure and chemical composition.
Preparation and characterization of multilayered titanium/titanium-diamond-like carbon films
Authors: Huang Jiang-Tao  , Gu Kun-Ming  , Mao Fei  , Yu Lie  , Tang Jiao-Ning  ,   Key Laboratory of Special Functional Materials of Shenzhen, School of Materials, Shenzhen University, Shenzhen 518060, China;,   College of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China
Published: December 2020

The titanium/titanium diamond-like carbon (Ti/Ti-DLC) multi-layered films are deposited by combined electron cyclotron resonance microwave plasma enhanced chemical vapor deposition method and mid-frequency magnetron sputtering method using acetylene as the reactive gas and Ti target with a purity of 99.99%. The structures, compositions and surface morphologies of the samples are characterized by X-ray diffraction, scanning electron microscope, and X-ray photoelectron spectrometer. The mechanical properties of Ti/Ti-DLC multilayer films are investigated by microhardness tester, friction wear test instrument and surface roughmeter. The results show that TiC phase appears in multilayered film. The main growth mode of the film is island mode and there exists columnar crystal structure neither in Ti layer nor Ti-DLC layer. The properties of the multi-layered film, including composite hardness, friction coefficient, surface morphology and surface roughness are affected by the modulation period . It is shown that nano-hardening effect takes place when is small while large particles appear on the surface of the film, leading to a large surface roughness and friction coefficient. The layered structure of the film is not clear when 50 nm.
Enlargement of current spin polarization in organic spintronic device
Authors: Dou Zhao-Tao  , Ren Jun-Feng  , Wang Yu-Mei  , Yuan Xiao-Bo  , Hu Gui-Chao  ,   College of Physics and Electronics, Shandong Normal University, Jinan 250014, China
Published: December 2020

Using the spin diffusion-drift equation and considering the effects of the electric fields and the special carriers in organic semiconductors, the enlargement ratio of current spin polarization in a simple T-shaped organic spintronic device is theoretically studied. It is found that the significant enlargement ratio of the current spin polarization can be acquired by adjusting the electric field and the polaron ratio in organic semiconductor.
Numerical simulation on the early dynamics of barium clouds released in the ionosphere
Authors: Hu Yao-Gai  , Zhao Zheng-Yu  , Zhang Yuan-Nong  ,   College of Electronic Information, Wuhan University, Wuhan 430079, China
Published: December 2020

Based on a neutral barium cloud diffusion model, considering the oxidation and ionization loss of barium atoms, the early (t 100 s) evolution characeristics, morphologies, brightnesses and electronic density distributions of barium clouds released in the ionosphere are discussed in this paper. The numerical simulation results are presented for the early dynamics of barium clouds with different released masses (1, 10 kg), different release altitudes (250, 300 km), and different initial shape factors (1, 10).
The study of micro-bulk micromegas
Authors: Fan Rui-Rui  , Hou Feng-Jie  , Ouyang Qun  , Fan Sheng-Nan  , Chen Yuan-Bo  , Yi Fu-Ting  ,   Institute of High Energy Physics, Chinese Academy of Sciences, State Key Laboratory of Particle detection and Electronic, Institute of High Energy Physics, Beijing 100049, China;,   Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

The fabrication process of micro-bulk micromegas is introduced. The energy resolution of the 55Fe X-ray is compared with the result of nylon line micromegas. Furthermore, the detailed effect of electric field is discussed.
The effect of relativity on the structures and transition properties of Li-like ions
Authors: Liu Shang-Zong  , Xie Lu-You  , Ding Xiao-Bin  , Dong Chen-Zhong  ,   Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730000, China
Published: December 2020

The transition energies, probabilities, and oscillator strengths for the electric dipole (E1) transitions between all levels of the ground state and the low-lying excited states of 1s2nl (n=24, l= s, p, d, f) configurations of Li atom and Li-like ions(Be+, C3+, O5+, Ne7+, Ar15+, Fe23 +, Mo39+, W71+, U89+) have been calculated, using the relativistic atomic computational code GRASP2K, which based on the Multi-configuration Dirac-Hartree-Fock (MCDHF) method. The norelativistic results for all of those transitions have been also obtained for comparative purposes by performing the similar calculations in the non-relativistic limit. The effects of relativity on the E1 transition energies and oscillator strengths of Li-like isoelectronic sequence are discussed with a particular emphasis, and some important conclusions are drawn. Comparison of the present results with other available data is also made, good agreement is obtained.
Study on measurement and simulation of manipulating electromagnetic wave polarization by metamaterials
Authors: Chen Long-Tian  , Cheng Yong-Zhi  , Nie Yan  , Gong Rong-Zhou  ,   Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
Published: December 2020

The polarization properties of electromagnetic wave have been gradually applied to the fields of communications, navigation and radar. In order to effectively control the polarization state of electromagnetic waves, a kind of metamaterial based on split-ring resonators(SRRs) is designed in this paper. The metamaterial is composed of SRRs, dielectric substrate and metal backplane, and it can completely convert incident linear-polarized waves into circular-polarized waves, elliptic-polarized waves and linear-polarized waves whose polarization is perpendicular to the incident wave. Our design is demonstrated by microwave experiments and simulations,and the experimental result and the simulation result are in good agreement with each other.
Adaptive scattering analysis of objects over a broad frequency band
Authors: Du Hong-Mei  , Chen Ming-Sheng  , Wu Xian-Liang  ,   Key Lab of Intelligent Computing & Signal Processing, Anhui University, Ministry of Education, Hefei 230039, China;,   Department of Physics and Electronic Engineering, Hefei Normal University, Hefei 230601, China
Published: December 2020

The error of asymptotic waveform evaluation (AWE) is estimated by the error analysis of rational approximation, and an efficient bandwidth estimation approach is finally proposed, which is used to form a new adaptive frequency-sweep analysis algorithm for a given frequency band in this paper. The broadband electromagnetic scattering analysis of three-dimensional (3-D) perfectly electrically conducting (PEC) objects with different shapes is performed, and dispersive dielectric object is considered. The effectiveness of the proposed method is proved by comparing the numerical results with those obtained from the analytical solution and the direct solution.
The study of the Raman spectra of SiC layers in TRISO particles
Authors: Fang Chao  , Liu Ma-Lin  ,   Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
Published: December 2020

The Raman spectra of the SiC layers in TRISO particles of fuel elements of HTGRs are studied. Through the analysis of the Raman shifts, the FWHM and intensities, the crystal phases, the residual stress and densities of SiC layers and corresponding spectroscopic features are clarified. The study of the 2D correlation spectrum of first order Raman scattering of SiC layer shows that the LO mode is much more sensitive than the TO mode to the change of density of SiC layer. All these conclusions are significant for synthesising TRISO particles and fuel elements of HTGRs and estimating their qualities.
Consistency of a complex delayed dynamical network with stochastic disturbance
Authors: Ke Chao  , Wang Zhi-Ming  , Tu Li-Lan  ,   Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081, China
Published: December 2020

This paper focuses on the consistency problem of a complex delayed dynamical network with stochastic disturbance. The complex network under consideration includes not only stochastic disturbance but also the varying time-delay which appear in the coupling term and the node system simultaneously. Therefore, such a network is more general. Based on the stochastic Lyapunov stability theory, linear feedback control and linear matrix inequality, some new asymptotic consistency sufficient conditions are established which guarantee the consistency for the nodes of this network and an isolated system in the delay-independent and delay-dependent levels. Finally illustrative simulation is provided to verify the correctness and effectiveness of the proposed scheme.
Preparation of graghene oxide/chitosan composite films and investigations on their nonlinear optical limiting effect
Authors: Lu Jing-Jing  , Feng Miao  , Zhan Hong-Bing  ,   College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, China
Published: December 2020

As a new kind of carbon nanostructured material, graphene and its derivatives have attracted extensive attention owing to their outstanding optical limiting (OL) properties. However, most of the current studies concentrate on liquid matrix. In this work, we use chitosan (CS) as matrix and homogeneously disperse graphene oxide (GO) into it to prepare GO-CS composite films. We comparatively study the different OL effects and mechanisms of GO in liquid and solid matrix. The results show that GO presents stronger nonlinear optical effect and weaker nonlinear optical scatter, which indicates that different from carbon nanotubes, GO may possess multi sort of nonlinear optical effects.
Theoretical and experimental investigation of air breakdown on single high power microwave based on the mixed-atmosphere propagation model
Authors: Zhou Dong-Fang  , Yu Dao-Jie  , Yang Jian-Hong  , Hou De-Ting  , Xia Wei  , Hu Tao  , Lin Jing-Yu  , Rao Yu-Ping  , Wei Jin-Jin  , Zhang De-Wei  , Wang Li-Ping  ,   PLA Information Engineering University, Zhengzhou 450001, China
Published: December 2020

Considering the series effects of high power microwave such as thermal fast electrons effect, collision frequency effect and ionization frequency effect, a unified high power microwave (HPM) propagation model is presented in this paper. A unified air-breakdown model for single-pulse HPM is discussed in detail and the breakdown threshold is determined. It is found that the frequency of plasma induced by high power microwave is greater than previous value. The threshold of air breakdown increases with altitude increasing under the same condition. When the threshold reaches a minimum, a reverse trend will appear. And the minimum value will be obtained in an area of 30-60 km. The typical phenomenon waveform and threshold are gained in the experiment of air breakdown in microwave darkroom. And a well uniform distribution of the air breakdown threshold is shown theoretically and experimentally.
Influence of modulation structure on the superhardness effect in c-VC/h-TiB2 nanomultilayer
Authors: Li Yu-Ge  , Li Guan-Qun  , Li Ge-Yang  ,   State Key Laboratory of Metal Matrix Composites, Shanghai Jiaotong University, Shanghai 200240, China
Published: December 2020

In order to reveal the relationship between modulation structure and superhardness effect, a series of c-VC/h-TiB2 nanomultilayers with different modulation structures is synthesized by magnetron sputtering technique. X-ray diffractometer, high-resolution transmission electron microscope and nanoindention device are employed to investigate the microstructures and mechanical properties of the multilayers. Based on the experimental results, a relation map of modulation structure and superhardness effect is established for the nanomultilayer composed of c-VC and h-TiB2 with four regions. In these regions, superhardness effect could be generated only in the region with sharp interface and coherent growth structure. In other regions, the change of modulation structure leads to the change of the microstructure, and the hardness will decrease accordingly. The map could provide reference for obtaining superhardness effect by designing modulation structure in those analogous heterogenous nanomultilayers.
Atomistic characterization of a modeled binary ordered alloy solid-liquid interface
Authors: Zheng Xiao-Qing  , Yang Yang  , Sun De-Yan  ,   Department of Physics, East China Normal Universtity, Shanghai 200241, China
Published: December 2020

Using molecular dynamics simulations, we investigate the structure and transport properties of solid-liquid interface in a model ordered alloy. Our results show that the studied interface is a smooth interface. Due to the coexistence of structural order and chemical order, the structure of this interface is remarkably different from heterogeneous or pure element solid-liquid interface. The number density oscillates in a complicated way along the interface normal direction, and this oscillation goes into liquid around 30 Å. The two-dimensional structural analysis shows that the atoms form two-dimensional ordered clusters in the transition layer. The diffusion constant gradually increases from zero to a saturation value in the liquid side far from the interface. In the vicinity of the interface, the diffusion constant parallel to the interface direction is large than that along interface normal.
Room temperature deposition of highly conductive and transparent H and W co-doped ZnO film
Authors: Wang Yan-Feng  , Zhang Xiao-Dan  , Huang Qian  , Liu Yang  , Wei Chang-Chun  , Zhao Ying  ,   Institute of Photo-Electronic Thin Film Devices and Technology of Nankai University, Key Laboratory of Photo-Electronic Thin Film Devices and Technology of Tianjin, Key Laboratory of Opto-Electronic Information Science and Technology, Ministry of Education, Tianjin 300071, China
Published: December 2020

Highly conductive and transparent hydrogen and tungsten co-doped zinc oxide (HWZO) thin films are prepared at room temperature by pulsed DC magnetron sputtering using a WZO (98.5 wt.% ZnO, 1.5 wt.% WO3) ceramic target with different H2 flow rates. The influence of H2 flow rate on the structural, compositional, elemental valence state as well as electrical and optical properties are systematically investigated. The results indicate that the incorporation of H does not change the structure of tungsten doped zinc oxide (WZO) namely, both WZO and HWZO films are polycrystalline with hexagonal structure and a preferred orientation along c-axis, respectively whereas the crystallinity is firstly improved and then deteriorated with the increase of H2 flow rate. Furthermore, the reaction between Zn and O can be promoted by the incorporated H. With an optimal H2 flow rate, the carrier concentration increases from 3.32×1020 cm-3 for WZO film to 5.44×1020 cm-3 for HWZO film, and the resistivity decreases from 1.20×10-3 Ω·cm to 7.71×10-4 Ω·cm. The average transmittance in a range of 400-1100 nm is improved from 69.2% to 82.4 %, and the optical band gap is widened from 3.42 eV to 3.58 eV.
Experimental study of the settling and melting characteristics of equiaxed crystals in a falling tube
Authors: Zhou Peng  , Wang Meng  , Lin Xin  , Chen Lei  , Qiu Feng  , Huang Wei-Dong  ,   State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China
Published: December 2020

The morphology evolution of NH4Cl equiaxed crystal settling in a falling tube filling with its superheated aqueous solution is studied. The effects of superheating and initial crystal size on settling rate and melting velocity are analyzed. The results show that for a non-spinning equiaxed crystal, it will transform from a "quasi-symmetrical" morphology to "quasi-delta" morphology, and for a spinning equiaxed crystal, it is more likely to sustain its initial "quasi-symmetrical" morphology. By analyzing the drag coefficients of equiaxed crystals settling in the solution at different superheating degrees, it is found that higher superheating leads to a smoother shape of the equiaxed crystal, thus increasing its settling rate. For a large equiaxed crystal, higher complexity in shape and increase in settling velocity will lead to a higher melting velocity. In the settling process of crystal in superheated melt, the solute transport condition on the melting interface is weakened by the gradually reducing the settling velocity, resulting in a relatively steady melting velocity for a certain equiaxed crystal.
Dynamic scaling behavior of the space-fractional stochastic growth equation with correlated noise
Authors: Ma Jing-Jie  , Xia Hui  , Tang Gang  ,   Department of Physics, China University of Mining and Technology, Xuzhou 221116, China
Published: December 2020

In order to study the dynamic scaling behavior of the space-fractional stochastic growth equation with correlated noise, we simulate numerically the space-fractional Edwards-Wilkinson (SFEW) equation driven by correlated noise in (1+1)-dimensional case based on the Riesz-and the Grmwald-Letnikov-type fractional derivatives. The scaling exponents including growth exponent, roughness exponent and dynamic exponent with different noise correlation factors and fractional orders are obtained, which are consistent with the corresponding scaling analysis. Our results show that the noise correlation factors and fractional orders affect the dynamic scaling behavior of the SFEW equation, which displays a continuous changing universality class.
Parameter-adjusted stochastic resonance of first-order linear system
Authors: Tian Xiang-You  , Leng Yong-Gang  , Fan Sheng-Bo  ,   School of Mechanical Engineering, Tianjin University, Tianjin 300072, China
Published: December 2020

The output power spectrum and signal-to-noise ratio (SNR) of the first order linear system driven by sinusoidal and white noise signal are analyzed. The result shows that the linear system under additive noise does not perform traditional stochastic resonance (SR), but it reveals the parameter-adjusted SR in a broad sense, which means that a resonance peak appears in the curve of SNR versus system parameter. The output spectrum properties under different sampling frequencies are analyzed for a signal with an arbitrary frequency, leading to a conclusion that increasing sampling frequency properly can be beneficial to the detection of the character signal.