bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of thermal effect and its influence on output power of thin disk laser
Authors: Zhao Jian-Tao  , Feng Guo-Ying  , Yang Huo-Mu  , Tang Chun  , Chen Nian-Jiang  , Zhou Shou-Huan  ,   College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, China;,   Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900, China;,   North China Research Institute of Electro-Optics, Beijing 100015, China
Published: December 2020

A temperature model for a end-pumped thin disk laser with Gaussian beam intensity distribution and single pass absorption performance is built up according to the actual working state. Using infrared thermal image, temperature distribution, temperature variation with time and the temperature difference of the surface laser medium are measured at different pump powers. Experiment on thermal lens focal length of the thin disk laser medium is performed by utilizing Hartmann-Shack wave-front sensor. Considering the fact that thermal lens focal length of the laser medium changes with pump power, the model for analyzing the influence of thermal effect on output power of thin disk laser is presented, according to rate equations. The simulation results obtained in this paper show satisfactory agreement with experimental results. The research has the guiding significance for designing and optimizing thin disk lasers
Comparison of the resolutions of integral imaging three-dimensional display based on human vision
Authors: Wang Fang  , Zhao Xing  , Yang Yong  , Fang Zhi-Liang  , Yuan Xiao-Cong  ,   Key Laboratory of Optical Information Science and Technology of Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071, China
Published: December 2020

In order to present the visual resolution effects of different integral imaging systems in three-dimensional (3D) display applications, a method of comparing the resolutions of integral imaging 3D display based on human vision is proposed. The relative resolution parameter is defined by analyzing the relation between the integral imaging 3D system and resolving power of human eyes on the best viewing condition, and its relationship with the visual resolution effect viewed in the integral imaging 3D display system is analyzed. The results indicate that the size of lens array has an important influence on the visual resolution effect in the integral imaging 3D display system. According to the theoretical results of two examples show that the difference in relative resolution parameter between the systems is 1.75 times of that of traditional one. The experimental results are consistent with the theoretical analyses. The method proposed in this paper could have a certain directive significance for 3D display resolution evaluation.
Preparation and spectral characteristics of Bi-doped double cladding fiber
Authors: Wang Yan-Shan  , Jiang Zuo-Wen  , Luan Huan-Xun  , Zhang Ze-Xue  , Peng Jing-Gang  , Yang Lü-Yun  , Li Jin-Yan  , Dai Neng-Li  ,   College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Published: December 2020

Bi-doped double cladding fiber preform is prepared by modified chemical vapor deposition and solution doping process. The absorption spectrum of preform and the near-infrared (NIR) luminescence spectrum of fiber are experimentally investigated. The luminescence spectrum of the fiber shows a peak emission band at 1140 nm with a full-width at half-maximum (FWHM) of 130 nm under 976 nm LD exciting. Under 808 or 793 nm LD exciting, an ultra-broad NIR emission with an FWHM of more than 250 nm is observed in the Bi-doped fiber, and the range of luminescence spectrum is from 1000 to 1700 nm. After the heat treatment of the Bi-doped fiber preform slice under 900 ℃ for 1 h, under 808 nm LD exciting, the fluorescence intensity is about 4 times higher than that of the perform slice without heat treatment. The results indicate that the Bi-doped double cladding fiber is a promising gain medium used for ultrashort fiber lasers and tunable fiber lasers.
Thermoelectric properties of (AgSbTe2)100-x (GeTe)x fabricated by hot pressing method
Authors: Huo Feng-Ping  , Wu Rong-Gui  , Xu Gui-Ying  , Niu Si-Tong  ,   Key Laboratory of New Energy Materials of Beijing, School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
Published: December 2020

Using pure metal Ag, Te, Ge and Sb powders as raw materials, (AgSbTe2)100-x-(GeTe)x (x=8090) (TAGS) are synthesized by vacuum reaction. X-ray diffraction (XRD) analysis results show that after sintering the alloys each have a rhombohedral structure. TAGS power is sintered by hot pressing method. Their phase compositions, crystal structures and morphologies are characterized by XRD and scanning electron microscope analysis methods. Their electric conductivities are measured by direct current method. Their Seebeck coefficients are measured when a temperature difference (T=14℃) is applied along two ends of sample. Through testing the thermoelectric properties of materials, the variations of different performance parameters of the sample are investigated in a temperature range of 30500℃. The results show that the sample is nano crystals and its thermoelectric properties change as the composition changes. We can see that TAGS-80 has a good thermal performance, with ZTmax=1.8 at 530℃.
Measurement of the hole mobility in the blend system by space charge limited current
Authors: Yu Huang-Zhong  ,   State Key Laboratory of Subtropical Building Science, Department of Physics, South China University of Technology, Guangzhou 510640, China;,   Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640, China
Published: December 2020

The measurement of carrier mobility in organic semiconductor material and device is one of important study contents. The hole-only devices based on the different solvent blends of poly (3-hexylthiophene) (P3HT) and [6, 6]-phenyl C61-butyric acid methyl ester (PCBM) as acceptor are fabricated, the structures of the devices are all ITO/PEDOT:PSS/P3HT:PCBM/Au. The hole mobilities in the blend systems with different solvents and various annealing treatments are measured by the space charge limited current method. The results show that the J-V curves of charge transfer in the devices meet Mott-Gurney equation, the hole mobilities in the active layer with different solvents are different, the active layer formed with high boiling point solvent 1, 2-dichlorobenzene possesses higher hole mobility, heat treatment contributes to the improvement of the hole mobility in the devices. The reason of change of hole mobility is analyzed.
Analytical modeling of coil impedance based on truncated region eigenfunction expansion method in eddy current tube inspection
Authors: Fan Meng-Bao  , Yin Ya-Dan  , Cao Bing-Hua  ,   College of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, China;,   College of Information and Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, China
Published: December 2020

In order to calculate theoretically the coil impedance, the separation of variables method and the Cheng matrix method are used to establish the analytical model by applying the magnetic insulation condition in eddy current tube detection with encircling probes inside and outside respectively. In the established model, there exists a definite integral related to modified Bessel function. Gaussian integral algorithm is proposed to accurately perform the numerical calculation. Simulations are carried out on the thinning of a copper tube wall thickness using the presented model, traditional Dodd model and finite element model. Their results are in good agreement with each other, demonstrating that the derived analytical model is correct. Compared with the Dodd and finite element models, the improved model has some advantages such as good efficiency, easy adjustment of accuracy and so on.
Terahertz broadband antireflection photonic device with graded refractive indices
Authors: Chen Yu-Ting-Wu  , Han Peng-Yu  , Kuo Mei-Ling  , Lin Shawn-Yu  , Zhang Xi-Cheng  ,   Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy 12180, USA;,   Physics Department, Rensselaer Polytechnic Institute, Troy 12180, USA
Published: December 2020

High resistivity silicon is a very common optical component in a terahertz system. However, its high relative refractive index of 3.42 causes a large impedance mismatch at the silicon-to-air interface. This severely reduces the available power in a terahertz system which motivates researchers to find a good anti-reflection solution. In the terahertz region, the lack of proper materials for broadband anti-reflection severely hinders such a research development. A photonic grating with graded refractive indices is demonstrated on silicon. Compared wich the case of planar silicon wafer, the transmission is observed to increase from 0.2 THz to over 7.3 THz for a device with 15 m period, which covers most of the terahertz band. With a striking relative 3 dB bandwidth of 116.3%, the device is polarization-independent and can be used under a wide incidence angle.
Analysis of organic photovoltaic devices with MoOx doped 4,4,4-tris(N-(3-methylphenyl)-N- phenylamin) triphenylamine as hole transport layer
Authors: Zhao Li  , Liu Dong-Yang  , Liu Dong-Mei  , Chen Ping  , Zhao Yi  , Liu Shi-Yong  ,   State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
Published: December 2020

MoOx doped 4,4,4-tris(N-(3-methylphenyl)-N-phenylamin) triphenylamine (m-MTDATA) is used as a hole transport layer to improve the efficiency of CuPc/C60 small molecular organic photovoltaics. A series of devices is fabricated in a high vacuum system. One of the devices with the structure of indum tin oxides (ITO)/m-MTDATA:MoOx(3:1)(30 nm)/CuPc(20 nm)/C60(40 nm)/Bphen (8 nm)/LiF(0.8 nm)/Al(100 nm) shows that the following parameters are achieved: the open circuit voltage Voc = 0.40 V, short-circuit current Jsc=6.59 mA/cm2, fill factor of 0.55, and power conversion efficiency p=1.46% under AM1.5 solar illumination. The efficiency of the device is improved by 38% compared with that of the device without hole transport layer ITO/CuPc(20 nm)/C60(40 nm)/Bphen(8 nm)/LiF(0.8 nm)/Al(100 nm). The improvement of the device performance may be attributed to the addition of m-MTDATA:MoOx (3:1) (30 nm) hole transport layer that reduces the contact resistance between the ITO electrode and the organic layer, thus reducing the overall device series resistance and improving the efficiency of the device.
Parameterized inversion of frequency sounding data in horizontally stratified transverse isotropic medium
Authors: Zhou Jian-Mei  , Wang Hong-Nian  , Yao Jing-Jin  , Yang Shou-Wen  , Ma Yin-Zhi  ,   College of Physics, Jilin University, Changchun 130012, China;,   China Railway Resources Mineral Exploration Company, Beijing 100039, China
Published: December 2020

In this paper, we advance a fast iterative inversion algorithm of frequency electromagnetic sounding data to simultaneously reconstruct the horizontal and the vertical conductivities and interface each bed in the horizontally stratified transversely isotropic (TI) medium. First, applying the analytic expression of the electromagnetic dyadic Green's functions in the TI medium, we realize the forward modeling of the frequency sounding via the fast algorithm of Sommerfeld integral. Then using the perturbation principles and Fourier inversion transform, we establish an efficient computation of Frchet derivatives of the frequency sounding data with respective to all the model parameters. And we use the least square criterion, the normalization and singular value decomposition to iteratively recovery all model parameters. Finally, numerical results validate the inversion algorithms and their antinoise ability.
Dynamic wavefront correction with a fast liquid-crystal on silicon device of pure phase
Authors: Liu Chao  , Hu Li-Fa  , Cao Zhao-Liang  , Mu Quan-Quan  , Peng Zeng-Hui  , Xuan Li  ,   State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;,   Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

In order to increase the response speed of the liquid crystal phase modulator (LCPM), a new kind of fast liquid crystal material is designed and synthesized, and a corresponding LCPM, called liquid crystal on silicon (LCOS), is fabricated. We test the phase modulation of the LCOS and examine its wavefront correction ability on static and disturbed wavefront. First, the electro-optical response is tested. The response time to a phase modulation quantity of 780 nm is 2 ms. Second, the phase modulation of the LCOS is tested and linearized. Third, the 3 dB closed-loop and open-loop disturbance rejection bandwidths of the adaptive optics system (AOS) are measured to be 16 and 18 Hz, respectively. Finally, the simulated correction of 26 Hz turbulence with the open-loop AOS is conducted. After correction, the Strehl ratio increases from 0.026 to 0.225. Therefore, with our fabricated LCOS, the liquid crystal AOS is able to correct the turbulence below 30 Hz.
Chaos synchroniztion by function coupling in a class of nonlinear dynamical system
Authors: Qin Wei-Yang  , Sun Tao  , Jiao Xu-Dong  , Yang Yong-Feng  ,   Department of Engineering Mechanics, Northwestern Polytechnical University, Xi'an 710072, China
Published: December 2020

To realize the synchronization of nonlinear dynamical system, the general control method is unidirectional linear coupling. Research on function coupling of chaos synchronization is not enough, so there arises a question: for nonlinear dynamical system, if chaos synchronization is realized by linear coupling, whether can any type of function coupling always make the system go to chaos synchronization? In this paper, a class of nonlinear dynamical system is considered and the relation between linear coupling and function coupling is investigated. It is proved that if linear coupling can make chaos synchronization, then any function satisfying some conditions can do so too. The condition is given and proved. Finally for Duffing system, three coupling functions are used to prove the analytical result. The simulation results show that the conclusion is correct.
The calculation of excitation cross-sections of collisions between Ne isotope atoms with HF molecule
Authors: Wang Xiao-Lu  , Linghu Rong-Feng  , Yang Jian-hui  , Lü Bing  , Gao Tao  , Yang Xiang-Dong  ,   School of Physics and Electronic Science, Guizhou Normal University, Guiyang 550001, China;,   China Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;,   School of Physics and Electronic Science, Guizhou Normal College, Guiyang 550018, China;,   School of Physics and Electronic Engineering, Leshan Teachers College, Leshan 614004, China
Published: December 2020

In this paper, we use the Huxley potential function to fit the interaction energy data, which have been calculated at the theoretical level of the QCISD(T)/aug-cc-pVTZ. Differential and partial cross-sections of 16Ne, 20Ne, 34Ne atoms and HF molecule collisions are calculated by the accurate close-coupling approximation method when the incident energy is 100meV. We study the changing tendencies of Ne-HF collisional cross-sections with Ne isotopic substitution.
Structures and stabilities of VOxH2O (x= 15) clusters
Authors: Jin Rong  , Chen Xiao-Hong  ,   School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu 610039, China
Published: December 2020

The equilibrium geometries, vibrational frequencies of VOxH2O (x= 15) and interactions between H2O with VOx(x= 15) are studied by using the density functional theory B3LYP/DZP method. The results show that ground states for VOxH2O (x= 15) belong to C1 point group symmetry,their electronic state is 2A, and in ground state of VOxH2O (x= 1, 4, 5) water molecule H2O is dissociated; H2O molecule is absorbed easily in VOx(x= 15) and VOxH2O(x= 15) are formed; In VOxH2O(x=15), chemical activations of VOxH2O (x= 1, 4, 5) are lower than those of VOxH2O (x= 2, 3); the sequence of interaction strength between H2O and VOx(x= 15) is VO4H2O VO5H2O VOH2O VO3H2O VO2H2O; there is possibility that OH segment and H atom are dissociated easily from VOH2O and VO5H2O, respectively by visible light exposure. Criterion that H2O molecule is dissociated in VOxH2O(x= 15) is obtained by analyzing frequency spectrum.
First principles study of the uniaxial compressive strength of bct-C4 carbon allotrope
Authors: Li Qing-Kun  , Sun Yi  , Zhou Yu  , Zeng Fan-Lin  ,   Postdoc Station of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;,   Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001, China;,   School of Physics and Electronic Engineering Heilongjiang University, Harbin 150080, China;,   The Department of Astronautics Science and Mechanics, Harbin Institute of Technology, Harbin 150001, China
Published: December 2020

bct-C4 carbon allotrope has been attracted great interest because its excellent mechanical properties. In this paper, we study the elastic properties and the strength properties of bct-C4 carbon by first-principles method. Our results show that bct-C4 presents a super uniaxial compressive strength of 524.3GPa, which is 6.9% more than the corresponding value of diamond. The high compressive strength originates from the high compressive rate of chemical bond deviating from compressive direction. Our work suggests that bct -C4 carbon can be widely used in the area of high pressure research.
Spectroscopic parameters and molecular constants of X1+ and a3 electronic states of BF radical
Authors: Shi De-Heng  , Niu Xiang-Hong  , Sun Jin-Feng  , Zhu Zun-Lue  ,   Department of Foundation, The First Aeronautical College of Air Force, Xinyang 464000, China;,   College of Physics & Information Engineering Henan Normal University, Xinxiang 453007, China
Published: December 2020

The potential energy curves (PECs) of the X1+ and a3 electronic states of the BF radical are studied by employing the ab initio quantum chemical method. The calculations are performed by using the complete active space self-consistent field (CASSCF) method followed by the valence internally contracted multireference configuration interaction (MRCI) approach in combination with the basis set, aug-cc-pV6Z, for internuclear separations from 0.095 to 1.33 nm. The effects of the Davidson modification and core-valence correlation and relativistic corrections on the PECs are included. The way to consider the relativistic correction is to employ the second-order DouglasKroll Hamiltonian approximation. The relativistic correction is carried out at the level of cc-pV5Z basis set. And the core-valence correlation correction is made by using the cc-pCV5Z basis set. With the PECs obtained here, the spectroscopic parameters (De, Re, e, exe, eye, Be and e) are determined and compared with those reported in the literature. With the PECs obtained by the MRCI+Q/aug-cc-pV6Z+CV+DK calculations, the complete vibrational states are computed for each electronic state when J = 0. And the vibrational levels, the inertial rotation constants and the centrifugal distortion constants of the first 20 vibrational states of each electronic state are reported. On the whole, as expected, the spectroscopic parameters and molecular constants closest to the experimental data are determined by the MRCI+Q/ aug-cc-pV6Z+DK+CV calculations for the two electronic states.
Theoretical study of the R-branch transition spectral lines of 35Cl2+ ion
Authors: Li Hui-Dong  , Sun Wei-Guo  , Fan Qun-Chao  , Feng Hao  ,   Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;,   School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu 610039, China
Published: December 2020

Based on the physical energy expression of diatomic molecule, an analytical formula is developed by taking multiple differences to predict the R-branch rovibrational transition spectral lines of diatomic system. Only 15 accurate experimental transition lines, and two rotational constants Bv, Bv corresponding to transition band (v, v) are needed when the new formula is used. The new formula is used to study the transition lines of (3, 7) and (4, 8) bands of the A2uX2g system of Cl2+ ion. Not only the experimental transition lines are reproduced, but also the lost ones, especially the high-lying transitions ones are obtained.
Dependence of nonsequential double ionization of He on intensity ratio of orthogonal two-color field
Authors: Tong Ai-Hong  , Feng Guo-Qiang  , Deng Yong-Ju  ,   Department of Physics and Electronics, Hubei University of Education, Wuhan 430205, China
Published: December 2020

Using classical ensemble model, the dependence of nonsequential double ionization of He on intensity ratio of orthogonal two-color field is investigated. It is shown that this dependence is related to the relative phase() of two-color pulse. When =0.25, with intensity ratio increasing, correlated momentum distribution along the polarization of long wavelength field changes from correlation to anticorrelation pattern; when =0.35, 0.45, correlated momenta are mainly distributed in the first and third quadrants, correlation pattern is nearly unchanged with the variation of intensity ratio. Back analyses of recollision time, recollision angle, recollision momentum of double ionization trajectories are responsible for the above results, and reveal the control of recollision time and the recollision angle in NSDI by orthogonally polarized two-color field.
Molecular dynamics simulation of the influence of Cu(010) substrate on the melting of supported Co-Cu bimetallic clusters
Authors: Zhang Ying-Jie  , Xiao Xu-Yang  , Li Yong-Qiang  , Yan Yun-Hui  ,   College of Sciences, Northeastern University, Shenyang 110819, China;,   School of Electronics Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China;,   School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China
Published: December 2020

Structural evolution and thermal stability of nanoclusters supported on the substrate play a key role in their applications. In this paper, we study the melting of the mixed Co281Cu280 bimetallic cluster with the icosahedral configuration by using molecular dynamics simulation with a general embedded atom method. The influence of the free or fixed Cu(010) substrate on the melting of the supported cluster is explored. It is found that the melting is strongly related to the substrate condition. There is a sharp increase in the temperature-energy curve for the cluster on the free substrate. The melting point (1320 K) is much lower than that (1630 K) of the cluster on the fixed substrate. The icosahedral configuration is converted into epitaxial cluster along the (010) of the substrate. Premelting occurs for the epitaxial cluster with the increase of temperature. The premelted atoms diffuse to the surface of the substrate and form surface layer until the cluster melt. The variation of the atomic spreading for the cluster on the free substrate is different from the case on the fixed substrate due to the atomic embedding into the substrate.
Study on the interaction between a sheet electron beam and the slow-wave structure for dielectric-loaded rectangular Cerenkov maser
Authors: Chen Ye  , Zhao Ding  , Wang Yong  ,   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

A three-dimensional model for the interaction between a sheet electron beam and the slow-wave structure of dielectric-loaded rectangular Cerenkov maser is proposed. Based on this model, the hybrid-mode dispersion equation and its analytical solution are derived by using the field-match method and the Borgnis function method. Through numerical calculations, the effects of dielectric layer thickness, beam voltage, current density, bean thickness and beam-dielectric layer gap on the linear growth rate are analyzed.
Improvement of the technology of making multi-mode polysiloxane waveguides
Authors: Wen Chang-Li  , Ji Jia-Rong  , Dou Wen-Hua  , Feng Xiang-Hua  , Xu Rong  , Men Tao  , Liu Chang-Hai  ,   State Key Laboratory of Astronautic Dynamics, Xi'an 710043, China;,   College of Opto-Electronics Science and Engineering, National University of Defense Technology, Changsha 410073, China
Published: December 2020

In this paper, we present an improved technology of making multi-mode polysiloxane waveguides. Through this kind of improvement, we can solve these problems such as reducing the number of air bubbles, demoulding, uncuring of the core layer, the chemical reaction between the core layer and the cover layer,etc. Finally, more than 80% of waveguides made by us can be successful, but before the improvement of the technology we can only have less than 40% successful waveguides. The longest waveguides can be 22.5 cm in length, compared with the 21 cm of previous ones. The propagation loss of the waveguides is 0.21 dB/cm (850 nm) by cutting back method, but before the improvement we can only have a loss of 0.3 dB/cm (850 nm). So the improvement of the technology is important in optical waveguides making.
Study of the M2 factor for the single-aperture coherent laser beam synthesis system
Authors: Li Jian-Long  , Feng Guo-Ying  , Zhou Shou-Huan  , Li Wei  ,   College of Nuclear Science and Engineering, Sichuan University, Chengdu 610065, China;,   School of Electronics And Information Engineering, Sichuan University, Chengdu 610064, China
Published: December 2020

Beam quality M2 factor of the single-aperture coherent laser beam synthesis system is a major problem to be solved. Based on the definition of second-order moment, beam quality M2 factors of the coherently combined beam supposed by the basic model TEM00, TEM01and TEM10 are presented by some analytical expressions in this paper. And, the effects produced by the beam waist width, the propagation distance, the ratio of the two amplitudes and the distance between the two coherent sources on the beam quality M2 factor are numerically analyzed. Some results show that the beam quality M2 factor of the coherently combined beam is unchanged when the propagation distance parameter d1100. And the experiment is carried to verify some theories of the two TEM00 coherently combined beam.
Novel flux concentrator with a single CSRR surrounded by a resonator for radio frequency superconducting quantum interference device
Authors: Wang Yang-Jing  , Xie Yong-Jun  , Lei Zhen-Ya  ,   Science and Technology on Antenna and Microwave Laboratory, Xidian University, Xi'an 710071, China;,   Beihang University, Beijing 100191, China
Published: December 2020

A novel flux concentrator surrounded by a resonator is proposed in this paper. A complementary single split ring resonator (single CSRR) is introduced for the flux concentrator, while the resonator surrounding the flux concentrator employs a third-order stepped-impedance hairpin resonator (SIR). High frequency structure simulation software ANSYS HFSSv.11 is used to simulate the proposed flux concentrator and resonator. Moreover, the single CSRR is analyzed theoretically. Simulation and theoretical results shows that the novel flux concentrator surrounded by a resonator introduces a single CSRR, which improves the flux focus effect of the concentrator significantly, and so enhances the performance of coupling between the RF SQUID and the flux concentrator (the coupling coefficient ksc is improved 2 times) and increases the effective area to 1.227 mm2.
Multi-channel multifunctional optical differentiator based on phase modulation and linear filtering
Authors: Luo Bo-Wen  , Dong Jian-Ji  , Wang Xiao  , Huang De-Xiu  , Zhang Xin-Liang  ,   School of Optoelectronics Science and Technology Huazhong University of Science and Technology, Wuhan 430074, China
Published: December 2020

Multifunctional photonic differentiation is robust in optical computing and optical signal processing. We theoretically propose a multifunctional optical differentiator based on phase modulation and linear filtering. We also experimentally demonstrate two kinds of differentiators by using a phase modulator cascaded a fiber delay interferometer (DI) whose transmission spectrum is approximately linear. Difference between the two differentiators relies on whether the differentiated signals are formed by the optical intensity or the optical field of the output signal, which in turn depends on the relative shift between the signal wavelength and the closest notches of a linear filter. We also show the average errors of all kinds of differentiations and results show that the increase of the degree of linearity of the transmission spectrum of the DI will reduce the average error. Moreover, we demonstrate multi-channel multifunctional differentiation due to the comb spectrum of the DI.
Intensity properties of output light in prisms laser gyro with mechanical dither bias
Authors: Yao Cheng-Kang  , Zeng Xiao-Dong  , Cao Chang-Qing  ,   School of Technical Physics, Xidian University, Xi'an 710071, China
Published: December 2020

For the modulation phenomenon of output light intensity in the laser gyro consisting of totally reflecting prisms during its dither bias, the effect of mechanical dither is calculated and analyzed systematically. By the numerical simulation and finite element analysis methods, an analytical expression for the output light intensity of the laser gyro is derived as a function of stress induced birefringence and deviation of photodetector. A new laser gyro type with the symmetic rectangle structure that can improve the stability of optical output is suggested for the first time. The results show that the position assembly accuracy of the photodetector and the stress induced birefringence have a significant effect on light intensity modulation. Reducing the photodetector deviation and using symmetic prisms material with a suitable refractive index, the extent of intensity modulation could be reduced by over 52.63%. The analytic study provides an important reference for improving the quality of output light and the reliability of prisms laser gyro.
Heterodyne research on times delay of laser pulses based on active Fabry-Perot cavity
Authors: Bai Yan  , Zhao Wei-Jiang  , Ren De-Ming  , Qu Yan-Chen  , Liu Chuang  , Yuan Jin-He  , Qian Li-Ming  , Chen Zhen-Lei  ,   Institute of Opto-Electronics, Harbin Institute of Technology, National Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin 150080, China
Published: December 2020

The delay theoretical analysis result of single-longitudinal-mode pulse injected in active Fabry-Perot cavity has been obtained. The gain in Fabry-Perot cavity has been calculated and the numerical simulation result of output pulse has been obtained. The results show that when the energy of the pulse decreases at a certain value, the gain produced by increased pump particle population can compensate the loss in the cavity and the delay pulse can achieve steady state. In experiment, the active Fabry-Perot cavity is a Nd: YAG laser sided pumped by laser diode. For the pulse inputed externally, we achieve 140 pulses within 2 ups. Finally, the reference light is delayed using the active Fabry-Perot cavity. And we show the heterodyne experiment of signal light whose frequency shift generated by an acousto-optic modulation (AOM), and the experiment results accord with the frequency shift of the AOM and the error is less than 4%.
Dynamic characteristics of multivariate graph centrobaric trajectory in phase space of two-phase flow
Authors: Zhao Jun-Ying  , Jin Ning-De  ,   School of Electrical Engineering and Automation Tianjin University, Tianjin 300072, China;,   Electronic Technology Department, Tianjin Vocational College of Electronics & Information Technology, Tianjin 300350, China
Published: December 2020

We propose a multivariate graph centrobaric trajectory-based method for characterizing nonlinear dynamics from high-dimensional chaotic time series. After the optimal selecting of the embedding dimension and time delay, we map the high-dimensional vector point into the two-dimensional radial plane graph, i.e., the high-dimensional vector point is transformed correspondingly to a geometric polygon. By extracting the geometric location of the polygon barycenters, we can obtain the evolving feature of the barycenter dynamical trajectory. Then we use the moment quantity of the barycenter trajectory to distinguish different chaotic time series. Finally, we apply our method to the fluctuating signals measured from gas-liquid two-phase flow experiments. The results suggest that our method can be a powerful tool for not only distinguishing the different flow patterns but also investigating the dynamical evolving mechanism of flow patterns.
The analytic model between effective heat capacity and relaxation time in gas acoustic relaxation process
Authors: Jia Ya-Qiong  , Wang Shu  , Zhu Ming  , Zhang Ke-Sheng  , Yuan Fei-Ge  ,   Department of Electronics and Information Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;,   Department of Electronics and Information Engineering, Hunan Institute of Technology, Hengyang 421002, China
Published: December 2020

The acoustic relaxation is one important nature of gas, which is caused by the sound propagation in the polyatomic molecule gas. It is the basic relaxation process, which arises from the translational-vibrational degree of freedom (V-T) and the molecular energy transfer between different vibrational degrees of freedom (V-V) separately. By studying the molecule energy transition model of the basic acoustic relaxation processes of gas, we propose an analytic model reflecting the correspondence between effective specific heat capacity and relaxation time in this paper. Compared with the existing relaxation model, the analytic model provides the corresponding relationship between the vibrational specific heat capacity and the relaxation time in V-T and V-V. The solution procedure of the analytic model illustrates that the higher vibrational energy level is the determinant of the basic relaxation process. The effective heat capacity is the foundation of acoustic relaxation attenuation spectrum of gas. The relaxation attenuation spectra result from the analytic model in this paper, which is modified by fine-tuning the collision diameter of the gas molecule, are more consistent with the experiment data than with the existing theoretical value. It proves the correctness and validity of the analytic model.
Experimental study of time characteristic of optical radiation in femtosecond laser interaction with solid targets
Authors: Wang Guang-Chang  , Ma Chun-Sheng  , Zhang Jian-Wei  , Bai Chun-Yan  , Liu Yu-Hong  , Zheng Zhi-Jian  ,   Teaching and Research Section of Physics, Chengdu Medical College, Chengdu 610083, China;,   Departmant of Computer Science, Simao Teachers, College Puer, Puer 665000, China;,   Research Center of Laser Fusion, Academy of Engineering Physics of China(CAEP), Mianyang 621900, China
Published: December 2020

In this paper, the time-integrated image pattern of spatial distribution and time-resolved image of optical radiation are measured in the normal direction from the rear side of targets by employing optical streak camera on the 100 TW femtosecond laser facility. The image pattern of spatial distribution presents a strip-shape: the region of optical radiation has a radiation angle and optical intensity distribution, and contains various components; the time-resolved image of optical radiation presents the time-resolved pattern of the optical radiation, witch further proves that the transition radiation is intense, which has short duration (ps) and correspouns to duration of TR of 85.5 ps. and other optical radiations are weak, which have very long duration (ns). The time-resolved characteristic of optical radiation can provide new evidence for discrimination and judgement of TR.
The spall strength and shock compressive damage of AD95 ceramics
Authors: Sun Zhan-Feng  , He Hong-Liang  , Li Ping  , Li Qing-Zhong  ,   National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP, Mianyang 621900, China
Published: December 2020

The relationship between spall strength and impact stress of AD95 ceramics which is in a one-dimensional strain state is determined by velocity profile measurement of the free surface or the sample/window interface. All fiber displacement interferometer system for any reflector is used in velocity measurement. Further the relationship between shock compressive damage degree and impact stress is discussed. The results indicate that the stress threshold of AD95 ceramics against shock compressive damage is about 3.7 GPa, which is less than its Hugoniot Elastic Limit (HEL, about 5.47 GPa). When impact stress is less than the threshold, no compressive damage occurs, and the spall strength increases with impact stress gradually. When impact stress is greater than the threshold, shock compressive damage occurs and develops rapidly which leads to the decrease of the spall strength with impact stress. The spall strength falls to zero when the impact stress increases up to about the HEL, which indicates that the material has lost the ability to resist the tensile stress and severe shock compressive damage has happened.
The investigation on effect of property of ZnO photoelectric material by Ta-doping
Authors: Gong Li  , Feng Xiang-Yang  , Lu Yao  , Zhang Chang-Wen  , Wang Pei-Ji  ,   School of Physics, University of Jinan, Jinan 250022, China
Published: December 2020

In this paper, the electronic structure and the optical properties of ZnO doped with Ta are calculated by the first-principles method based on the density function theory. The calculation results show that fermi energy levels enter into the conduction band after Ta-doped. With the increase of Ta concentration, the bandgap of ZnO is reduced and dielectric function imaginary part, absorption coefficient, the refractive index, and reflectivity are all changed significantly. The imaginary part of dielectric function and the reflectivity shift toward the higher-energy region. The absorption edge shifts to ward the red. The relationship between electronic structure and optical properties is pointed out in theory.
A method of determining the highest temperature attained by magnetic material in the adiabatic magnetization
Authors: Chen Hui  , Zhang Guo-Ying  , Yang Dan  , Gao Jiao  ,   Department of Physics, College of Sciences, China University of Mining and Technology, Xuzhou 221008, China
Published: December 2020

Determining the highest temperature attained by a magnetic material in the adiabatic magnetization is important for the optimal selecting of magnetocaloric material. As an example, the Gd3Ga5O12 crystals are investigated. Under the superstrong magnetic field and at low temperature, the form of effective magnetic susceptibility is given based on the tendency-saturation law. The magnetic entropy change and the phonon entropy change as well as the magnetocaloric effect are calculated in a magnetic field range from 0 to 40 T. The calculated results are in good agreement with the measured data. A method of determining the highest temperature attained by magnetic material in the adiabatic magnetization is given by using the only intersection point between the curves of the saturation-magnetic entropy change and the phonon entropy change. The highest temperature in the adiabatic magnetization is predicted to be 64.7 K for the Gd3Ga5O12 crstal.
Preparation and characterization of nickel manganese ferrite
Authors: Gu Jian-Jun  , Han Jin-Rong  , Cheng Fu-Wei  , Zhao Guo-Liang  , Liu Li-Hu  , Sun Hui-Yuan  ,   Department of Physics, Hebei Normal University for Nationalities, Chengde 067000, China;,   College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050016, China;,   Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang 050016, China
Published: December 2020

Arrays of Ni1-xMnxFe2O4 (x = 0.0, 0.25, 0.5, 0.75) nanowires with an average diameter of about 80 nm are prepared by porous anodic aluminum oxide membrane poured sol technique. X-ray diffraction analysis shows that the nickel manganese ferrites nanowires with cubic spinel structure are synthetized. Scanning electron microscopy and transmission electron microscope images indicate that the nanowire arrays are composed of prolate spheroids with different crystal orientations. Magnetic measurements show that saturation magnetization increases and then decreases with Mn increasing. The change is related to the location and the substitution of ion in spinel structure. Compared with of block material NiFe2O4, the saturation magnetization of nickel ferrite nanowire arrays is low. This is due to the fact that the noncollinear magnetic structure in nanowire arrays become predominant.
Theoretical study and experimentation of magnetic quantum-dot cellular automata corner structure
Authors: Yang Xiao-Kuo  , Cai Li  , Kang Qiang  , Li Zheng-Cao  , Chen Xiang-Ye  , Zhao Xiao-Hui  ,   College of Science, Air Force Engineering University, Xi'an 710051, China;,   Department of Science Research, Air Force Engineering University, Xi'an 710051, China
Published: December 2020

Magnetic quantum-dot cellular automata (MQCA) corner structure consists of both ferromagnetic coupling and anti-ferromagnetic coupling. Signal propagation of corner structure for magnetic material Fe is theoretically investigated by applying an external clocking field method. Magnetization evolution image on signal propagation of the corner is presented by micromagnetic simulation; it is shown that Fe nanomagnets can ensure stable switching of corner including two kinds of lengthy coupling. The proposed corner structure is then fabricated by electron beam lithography, thermal evaporation and lift-off technologies. Scanning electron microscopy and magnetic force microscopy measurement results demonstrate perfect pattern and correct signal propagation of two types of coupling.
Study on glassy characteristics of dispersion transition in relaxor ferroelectrics
Authors: Chen Wei  , Cao Wan-Qiang  ,   School of Materials Science and Engineering, Hubei University, Wuhan 430062, China
Published: December 2020

Based on the common behavior of the Vogel-Fulcher relation followed by both dielectric dispersion of relaxor ferroelectrics in transition region and the viscosity-temperature relation for glassy liquids in supercooled state, vacancy compensation principles of donor doped barium titanate systematic ceramics are analyzed. By the introduction of the concept of configurational entropy, the temperature dependent Ti cation vacancy reaction potential is investigated, and the results show that the increase in donor content gives rise to the increase in disorder degree, the increase in Ti cation vacancy content, and the decrease in size of average polar region; on condition that configurational entropy satisfies the Vogel-Fulcher relation, Ti cation vacancy reaction regime and therefore the polar region will both increase with temperature lowing, and the variation of the regime causes dielectric dispersion of relaxor ferroelectrics. Frozen effect happens and dispersion disappears for the Ti cation vacancy reaction at a certain lower temperature.
Influence of active layer thickness on the performance of distyrylarylene derivative blue organic light-emitting device
Authors: Wu You-Zhi  , Zhang Wen-Lin  , Ni Wei-De  , Zhang Cai-Rong  , Zhang Ding-Jun  ,   State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, School of Materials Science & Engineering, Lanzhou University of Technology, Lanzhou 730050, China;,   Department of Applied Physics, School of Science, Lanzhou University of Technology, Lanzhou 730050, China
Published: December 2020

Thickness of emissive layer in organic electroluminescent device is one of the important factors affecting the device performance. In this report, a blue electroluminescent device with an active layer of 4, 4'-bis(2, 2'-diphenylvinyl) -1, 1'- biphenyl (DPVBi) is fabricated. The device performance varies with the thickness of DPVBi. With the increase of the DPVBi thickness between 1050 nm, the device luminance and efficiency at the same current density first increase and then decrease, the device with a DPVBi thickness of 40 nm exhibits the highest luminance of 15840 cd/m2 and a maximum external quantum efficiency of 3.2%, with Commission Internationale de l'Eclairage (CIE) co-ordinates being (0.15, 0.15). The luminescent spectral red shift and the color purity deteriorate when the thickness is over 40 nm, which can be attributed to a result of microcavity effect. In the meantime, the analysis from experimental results shows that the exciton diffusion length in DPVBi is between 2030 nm.
Research on fluctuation of bivariate correlation of time series based on complex networks theory
Authors: Gao Xiang-Yun  , An Hai-Zhong  , Fang Wei  ,   Lab of Resources and Environmental Management, China University of Geosciences, Beijing 100083, China;,   School of Humanities and Economic Management, China University of Geosciences, Beijing 100083, China
Published: December 2020

In order to study the fluctuation of bivariate correlation which had time series characters, this paper selected International crude oil futures prices and Chinese Daqing crude oil spot prices as the sample data, using the method of statistical physics to study. The modes of fluctuation of correlation were defined by coarse graining process. Then three problems modes' statistics, law of variation and evolution mechanism were analyzed by complex network theory and analytical method. The results indicated that forms of modes showed that consecutive days of weak or strong positive correlation, and modes obeyed the power-law distribution. There were three kinds of sub-groups appearing in the network of fluctuation of bivariate correlation. These sub-groups were fluctuation of weak positive correlation, strong positive correlation and unrelated, and a core mode existed in each category of sub-groups. Transmission and evolution of fluctuation of bivariate correlation were a few modes. The fluctuation of bivariate correlation was transmitted and evolved by a few modes. The fluctuation had periodicity that the transmission among modes need average 8.74 days and a whole volatility cycle need about 18.55 days. These results not only can be the analyze method between two variables but also provides idea for researching a general law in different variables.