bluuebunny/crossref_metadata_2025 huggingface dataset:
The imaging effect in radiation measurement
Authors: Cheng Xiao-Fang  , Xin Cheng-Yun  , Wang Lu-Ping  , Zhang Zhong-Zheng  ,   Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei 230027, China
Published: December 2020

The determination and mathematical descriptions of the difference between the imaging radiation measurement and the non-imaging radiation measurement which is of maturity are necessary for extending the radiation measurement from non-imaging technology to imaging technology. In this paper, the mathematical descriptions of the imaging and non-imaging radiation measurement are deduced based on the basic equations of radiation measurement and the correspondence between the infinitesimal planes of the target and sensor array. Because the imaging plane does not change the radiation transfer between the target and sensor, the mathematical descriptions of the imaging effect can be obtained by comparing the two mathematical descriptions. A concrete analysis of the imaging effect based on pinhole imaging and lens imaging is carried out. The results show that the primary cause of the imaging effect is the imaging optical axis angle while the subsidiary cause is the imaging zenith angle, and the influence of the subsidiary cause is determined by the difference between the imaging optical axis angle and the imaging zenith angle.
Optimization of piezoelectric sensor arrays in error sensing of active triple sound insulation structure
Authors: Ma Xi-Yue  , Chen Ke-An  , Ding Shao-Hu  , Zhang Bing-Rui  ,   Department of Environmental Engineering, College of Marine Engineering, Northwestern Polytechnical University, Xi’an 710072, China
Published: December 2020

The active triple sound insulation structure using planar loudspeaker as the secondary actuator can be easily implemented and has better sound insulation performance in the low frequency range. The key problem encountered when implementing such a control system is to sense the error signal which should be highly correlated with the radiated sound power. In this paper, the theory of sensing the radiation modes of simply supported beam using polyvinylidene fluoride (PVDF) arrays used in one-dimensional case is extended to two-dimensional structure, and then it is used in triple panel structure to optimally design the error sensing strategy. Based on the specific rule of sound energy transmission through triple panel structure, some key problems encountered in realizing the sensing system such as selection of the objective function, optimization of the number of PVDFs and implementing the sensing system, are analyzed thoroughly. The results obtained demonstrate that due to the fact that the majority of vibrating energy of radiated panel is stored in several limited number of panel modes, the amplitude of the first three order radiation modes can be obtained by simply summing the limited number of weighted PVDF film current output. And the weighted coefficient is fixed. The amplitudes of the radiation modes sensed by the proposed method are in good agreement with the theoretical value. The sensing accuracy of the error sensing system can be guaranteed, and this approach highly simplify the implementation of the error sensing system.
Wavefield propagation characteristics in fracture-induced TTI double-porosity medium
Authors: Kong Li-Yun  , Wang Yi-Bo  , Yang Hui-Zhu  ,   Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China;,   Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China
Published: December 2020

The direction of symmetry axis of parallel fracture set in fractured hydrocarbon reservoir affects the transmission of seismic waves markedly, so a medium named fracture-induced TTI (tilted transverse isotropy) double-porosity medium is studied here to discuss the effect of different dip and azimuth angles of a fracture system. Based on the theories of fracture-induced HTI (horizental transverse isotropy) double-porosity medium, the softness and dispersion matrixes of fracture-induced TTI double-porosity medium are derived with the application of Bond transform, and finally, single-order velocity-stress equations are obtained. Furthermore, numerical simulations in xoz plane of 2.5 dimensional vector wavefield are carried out by the method of high-order staggered-grid finite-difference under perfect matched layer (PML) boundary conditions. The results show that the dipand azimuth angles of fractures have great impacts on seismic wave propagation, since the angles can cause the phenomena of shear wave splitting and, in the two-layer model of fracture-induced TTI double-porosity, converted shear wave splitting and shear wave sub-splitting. All of these increase the complexity of seismic wavefield and will lay a foundation of further studies on seismic wave propagation in actual earth layers.
The Monte Carlo simulation of neutron shielding performance of boron carbide reinforced with aluminum composites
Authors: Dai Chun-Juan  , Liu Xi-Qin  , Liu Zi-Li  , Liu Bo-Lu  ,   College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Published: December 2020

Three groups of neutron shielding experiments were set up to study the shielding performance of B4C/Al composite, using the Monte-Carlo method. We have made the following changes: the content of boron carbide 20%–40%, neutron energy 200 eV–15 keV, material thickness 0.3–2 cm, so that we can draw the conclusions: the content of boron carbide and neutron transmission coefficient show a linear relation, with a big drop; under the same neutron energy, the neutron-shielding qualities of simulated specimens are for better than polyethylene boron carbide at the same content of B4C and water, copper, and concrete at the same thickness; an exponential decline relationship is exhibited by material thickness and neutron transmission coefficient, which change greatly with the increase in unit material thickness; the content of boron affects the thermal neutron transmission coefficient seriously. In the thermal neutron energy region, the change of per unit neutron energy(100 eV) has a big influence on neutron transmission coefficient. In the slow neutron energy region, the influence is small.
A fourth-order Runge-Kutta in the interaction picture algorithm for simulating coupled generalized nonlinear Schrödinger equation and its error analysis
Authors: Li Pan  , Shi Lei  , Mao Qing-He  ,   Anhui Provincial Key Laboratory of Photonics Devices and Materials, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
Published: December 2020

The numerical simulation method for accurately solving the coupled generalized nonlinear Schrödinger equations (C-GNLSE) is essential for describing the dynamic behavior of ultrashort pulse propagating in optical fiber and developing the corresponding nonlinear fiber-optic devices. C-GNLSE in the normal picture is first mapped into the interaction picture by the representation transformation, and then, the two coupled nonlinear partial differential equations in the interaction picture are solved in frequency domain, with synchronous data updating in each iteration step, by using the vector form of Hult’s fourth-order Runge-Kutta iterative scheme. The proposed vector form algorithm of fourth-order Runge-Kutta in interaction picture (V-JH-RK4IP) is verified by using it in simulating the supercontinuum generation in high birefringence photonic crystal fiber. Moreover, the V-JH-RK4IP algorithm also exhibits the highest accuracy and computational efficiency as compared to other classical algorithms.
Investigation about drag reduction annulus experiment of hydrophobic surface
Authors: Song Bao-Wei  , Guo Yun-He  , Luo Zhuang-Zhu  , Xu Xiang-Hui  , Wang Ying  ,   College of Marine, Northwestern Polytechnical University, Xi’an 710072, China;,   Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China;,   Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
Published: December 2020

For the drag reduction application of hydrophobic material, the drag characteristic of typical surface with different roughness or different hydrophobicity is studied by a new annulus experiment. The corresponding torque characteristic and drag reduction rate curve are acquired. The experiment indirectly calculate the surface friction of the annulus by measuring the torque of disk driving annulus and breaks through the limitation of scale in traditional microchannel experiment, avoids the drawbacks of too many influencing factors in water-tunnel experiment, and has important significance in macro application of hydrophobic material. The drag reduction effect of hydrophobic surface is proved at low Reynolds number in macroscale; however, at high Reynolds number, it will be weakened or even changed to drag producing effect, and the rapid increase of pressure drag is the major reason for increasing resistance. Through comparative analysis we find that at low Reynolds number, there will be greater effect of hydrophobicity for drag reduction; where as at high Reynolds number, the roughness will play a greater role, and may even be counterproductive to the increasing resistance.
Simulation and calculation of conducting property of Zn1-xTMxO (TM=Al, Ga, In)
Authors: Hou Qing-Yu  , Dong Hong-Ying  , Ma Wen  , Zhao Chun-Wang  ,   College of Sciences, Inner Mongolia University of Technology, Hohhot 010051, China;,   School of chemistry Engineering, Hohhot 010051, China;,   aterials Science, Inner Mongolia University of Technology, Hohhot 010051, China
Published: December 2020

Based on the density functional theory (DFT), using first-principles plane-wave ultrasoft pseudopotential method, the models for the unit cell of pure ZnO and Zn1-xTMxO (TM=Al, Ga, In) supercells at the same doping concentration were constructed, and the geometry optimization, total density of states, band structures for all models were carried out. The calculation results show that, In-doped ZnO has the best conductivity at the same doping concentration of 3.125 at% of (Al, Ga, In) high doped in ZnO, the calculation results agree with the experimental results.
Photon squeezing of the Rabi model
Authors: Yu Li-Xian  , Liang Qi-Feng  , Wang Li-Rong  , Zhu Shi-Qun  ,   School of Physical Science and Technology, Soochow University, Suzhou 215006, China;,   Department of Physics, Shaoxing University, Shaoxing 312000, China;,   Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, China
Published: December 2020

Recent experiments about the circuit cavity quantum electrodynamics have realized the ultrastrong couplings between the artificial atom and the photon, in which the coupling strengths have the same order of the photon frequency. In such a regime, the well-known rotating wave approximation is invalid, and the system dynamics is thus governed by the Rabi model. In this paper, we investigate the photon squeezing of the Rabi model. We find numerically that with the increase of the atom-photon coupling strength, the photon squeezing does not increase linearly, but displays a maximum in the ultrastrong coupling regime. In addition, we also reveal that the photonsqueezing can be enhanced by the counter-rotating terms of the Rabi model. Our results are of benefit to preparing the required squeezing state of the photon in experiment.
Quantum voting protocols based on the non-symmetric quantum channel with controlled quantum operation teleportation
Authors: Wang Yu-Wu  , Wei Xiang-He  , Zhu Zhao-Hui  ,   School of Computer Science and Technology, Huaiyin Normal University, Huai’an 223300, China
Published: December 2020

In the paper, we present a kind of quantum voting protocol, which is based on controlled quantum teleportation of local unitary operations in non-symmetric quantum channel. In this protocol, the umpire CA with zero knowledge proof quantum identity authentication ensures voter’s anonymous identity authentication. The counting institution Bob generates a high-dimensional Greenberger-Horne-Zeilinger entangled state to establish a high-dimensional quantum communication channel. Performing the local unitary operation on their low-dimensional quantum ballot, voter’s quantum vote is teleportated by asymmetric matrix measurement and scrutineer Charlie auxiliary measuring. With the scrutineer Charlie’s help, Bob achieves the voting result by the output of unitary operation. Compared with other general quantum operation teleportation quantum voting protocol, the protocol utilizes the quantum information and transmission of quantum channel, which have different dimensions, so single particle information cannot be stolen, and can prevent forgery. The electoral process is fair and undeniable, owing to Charlie’s supervision. Since the success probability of quantum teleportation of local unitary operations is 1, the quantum voting is reliable.
Fault tracking of rotating machinery under variable operation based on phase space warping
Authors: Fan Bin  , Hu Lei  , Hu Niao-Qing  ,   Science and Technology on Integrated Logistics Support Laboratory, College of Mechatronics and Automation, National University of Defense Technology, Changsha 410073, China
Published: December 2020

For fault prognosis of rotating machinery under variable operation, a fault tracking method based on phase space warping and smooth orthogonal decomposition (SOD) is presented to describe the degradation process of rotating machinery. Firstly, phase space is reconstructed using vibration time-series, and a tracking function of damage evolution is built by quantifying phase space warping. To compensate for cumulative model error and the error caused by variation of local probability distribution of the reference phase space points, the original time-series is partitioned into several data segments and the phase space is partitioned into several subspaces correspondingly. Several feature vectors are concatenated into tracking matrix. Secondly, the different trends caused by actual damage degradation and operation variety in the tracking matrix are separated by smooth orthogonal decomposition. According to smooth orthogonal values, dominant smooth orthogonal coordinates which reflect actual fault degradation trends are extracted. Finally, fault degradation process of bearing out-race is simulated. Rotating speed is varied during the degradation process. Applying the presented method to the degradation process tracking, the tracking matrix is built and decomposed by SOD, and the results show that the proposed method can track the evolution trend of the rotating machinery fault without the influence of operation condition variety.
Composition analysis and mechanism approach of the electrorheological fluids based on the precursor of TO2
Authors: Yang Su-Hong  , Zhao Li-Shan  , Wang Qiang  , Shen Rong  , Sun Gang  , Li Chen-Xi  , Lu Kun-Quan  ,   CAS Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;,   Department of Physics, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
Published: December 2020

We synthesize the powder of the precursor of TiO2, which shows the giant electrorheological effect but does not include the component of CaC2O4H2O. By use of X-ray diffraction, scanning electron microscope, inductively-coupled plasma spectrometer, themogravimetry-mass spectrum, etc, it is found that the precursor of TiO2 is amorphous powder with nanosize, and its components include TiOC2O42H2O and TiO(OH)2. The electrorheological fluid made by the powder shows a similar temperature characteristic to that made by the precursor of CaTiO3, i.e., when the powder is heated to the temperature above 160℃, the yield stress of the electrorheological fluid made by it decreases gradually, and when it is heated to 200℃, the giant electrorheological effect disappears completely. It is also found that the chemical reaction accompanies with the disappearance of the giant electrorheological effect is that the crystalized water in TiOC2O42H2O is volatilized in heating process. These characteristics can be observed in all electrorheological fluids made by the precursor of other titanate, so we conclude that TiOC2O42H2O is the key component for this series of giant electrorheological fluids.
Origin of energetic carbon ions with different charge states in ultrashort laser-thin foil interactions
Authors: Liu Meng  , Su Lu-Ning  , Zheng Yi  , Li Yu-Tong  , Wang Wei-Min  , Sheng Zheng-Ming  , Chen Li-Ming  , Ma Jing-Long  , Lu Xin  , Wang Zhao-Hua  , Wei Zhi-Yi  , Hu Bi-Tao  , Zhang Jie  ,   School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China;,   Key Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;,   Department of Physics, Shanghai Jiaotong University, Shanghai 200240, China
Published: December 2020

High charge state carbon ions are observed from the rear surface of thin foil irradiated by intense femtosecond laser pulse at intensities up to 6.4×1018 W/cm2. The origin of the ions is studied by analyzing the basic ionization process occurring at the rear surface. It is shown that the normally dominant ionization process is field ionization by barrier suppression for charge states less than He-like (C4+), while collisional ionization is significant for C5+ and C6+.
Analysis of modal tomography for three-dimensional wavefront sensing of atmosphere turbulence
Authors: Zhang Lan-Qiang  , Gu Nai-Ting  , Rao Chang-Hui  ,   Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China;,   Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, Chengdu 610209, China;,   University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

Three-dimensional (3D) wavefront sensing of atmosphere turbulence is a key step to realize multi-conjugate adaptive optics technology. In this article, model tomography, which is one of the most important algorithms for 3D wavefront sensing, is analyzed in theory, the principle limitation of model tomography is proposed. Based on this view the reason for tomography error is discussed, and the simulation results for different errors are produced finally. The analysis shows that part Zernike model basis is used as a new basis of polynomial decomposition in model tomography, which leads to modal coupling error and aliasing error. The un-correlation of part Zernike model basis is the prerequisite to avoid modal aliasing error, but modal coupling error cannot be removed and we can only restrain its influence. Combined with simulation result a method with large field of view (FOV) sensing and small FOV reconstruction is proposed and gives a good performance to control modal coupling error.
Electromagnetic scattering from missile target above sea surface with finite element/boundary integral method
Authors: Xu Run-Wen  , Guo Li-Xin  , Fan Tian-Qi  ,   School of Sciences, Xidian University, Xi’an 710071, China
Published: December 2020

In this work, the finite element/boundary integral method (FE/BIM) combined with the domain decomposition method is introduced to study the electromagnetic scattering from the target above the rough sea surface. As the integral boundary can be set at anywhere with an arbitrary shape, the conformal truncated boundary is built to reduce the unknowns of the computational region combined with the domain decomposition method. In the interior region, the finite element method is used to solve the problem, whereas the artificial boundary condition can be obtained by the boundary integral method. The strategy of hybrid FE/BIM and the modeling method are presented with their validity evaluated by the method of moment, then bistatic scattering properties of a missile above the sea surface are discussed, and their dependence upon different incident angles, target height, wind speed above the sea, and the size of the missile are discussed in detail. The information of targets and the target detection can be retrieved and analyzed by the results in this paper.
Fuzzy adaptive extended Kalman filter SLAM algorithm based on the improved wild geese PSO algorithm
Authors: Chen Wei-Dong  , Liu Yao-Long  , Zhu Qi-Guang  , Chen Ying  ,   Institute of information Science and Engineering, Yanshan University, Qinhuangdao 066004, China;,   The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province, Yanshan University, Qinhuangdao 066004, China;,   Institute of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China
Published: December 2020

Because the problem of the extended Kalman filter localization and mapping algorithm priori noise model is difficult to manage, this paper proposes an improved wild geese particle swarm algorithm based on the fuzzy adaptive Kalman filter localization and mapping algorithm. We take advantage of the the fractional calculus to improve particle speed of evolution, and make use of chaos to improve the initialization of the particle and the precocious one when processing. The improvement of wild geese particle swarm algorithm is shown in convergence rate and avoiding premature, then they can improve geese particle swarm algorithm for fuzzy adaptive extended Kalman filter localization and mapping algorithm training. in contrast with geese particle swarm algorithm fuzzy adaptive extended Kalman filter simultaneous localization and mapping algorithm, the new algorithm positioning and composition has greatly improved.
Simulation study on hydrogen penning source discharge at low pressure
Authors: Shi Lei  , Qian Mu-Yang  , Xiao Kun-Xiang  , Li Ming  ,   Institute of Electronic Engineering, CAEP, Mianyang 621900, China
Published: December 2020

In order to better comprehend the dynamic behaviours of ion and electron during the Penning source discharge process under a low pressure and weak ionization condition, numerical simulation is carried out to study the penning source discharge and diffuse process. For constituting 2D axial symmetrical model and combining the particle simulation and Monte Carlo (PIC/MCC) method, elastic collision, excitation, and ionization reactions between electrons and hydrogen molecules, hydrogen atom and ions are taken into account. The effect of magnetic field configuration, secondary electron emission coefficient, derivational voltage, and gas pressure on the discharge characteristics is investigated. It has been found that the simulant discharge parameters, including electron and ion densities, anodic current and ionic current, H+ and H2+ densities, etc, are in good agreement with the experimental results. Based on our numerical simulation, the study of the hydrogen penning discharge is being changed from qualitative analysis to quantitative calculation, which is important for the design and optimization of the penning ion source.
Surface states of InAlN film grown by MOCVD
Authors: Yang Yan-Nan  , Wang Xin-Qiang  , Lu Li-Wu  , Huang Cheng-Cheng  , Xu Fu-Jun  , Shen Bo  ,   State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
Published: December 2020

The surface state properties (such as surface state density, time constant and level position related to the bottom of InAlN conduction band) of Ni/Au/-InAlN Schottky barrier diodes with nearly lattice matched (InN=18%) and tensilely (15%) or compressively (21%) strained InAlN barrier layer were evaluated, by using current-voltage (I-V), frequency-dependent capacitance-voltage (C-V) measurements and atomic force microscope (AFM) images. It was found that, with increasing content of In the surface state density increased and the barrier height of the Schottky contacts decreased, respectively. The C-V curves shifted toward the positive bias values with reducing measured frequencies, which became more apparent with increasing In content. It may be due to the hole emission from the surface states of Ni/Au/-InAlN Schottcky contacts. Atomic force microscope (AFM) images indicated that the InAlN surface became rougher with increasing In content, which may be the main reason for the increased surface state densities.
The impact of interface charges at the heterojunction on the carriers transport in abrupt InP/InGaAs heterojunction bipolar transistor
Authors: Zhou Shou-Li  , Li Jia  , Ren Hong-Liang  , Wen Hao  , Peng Yin-Sheng  ,   College of information engineering, Zhejiang Univ. of Technology, Hangzhou 310023, China
Published: December 2020

The carriers transport at the base-emitter interface of abrupt heterojunction bipolar transistors (HBTs) is controlled by thermionic emission and tunneling, which depends on the form and height of the energy barriers. The interface charges at the heterojunction disturb the energy barriers, thus bringing about the change of the electrical characteristics of HBT. Based on thermionic-field-diffusion model which combines the drift-diffusion transport in the bulk of the transistor with the thermionic emission and tunneling at the interface, a conclusion can be drawn that the positive interface charges can improve the electrical characteristics of abrupt InP/InGaAs HBT, while the negative interface charges deteriorate the devices.
SPFGO effects on the electroluminescence and photovoltaic response in conjugated polymers
Authors: He Jia-Qi  , He Da-Wei  , Wang Yong-Sheng  , Liu Zhi-Yong  ,   Institute of Optoelectronic Technology, Beijing Jiaotong University, Key Laboratory for Information Storage, Displays and Materials, Beijing 100044, China
Published: December 2020

This paper studies the influence of poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) on solution-processable functionalized graphene oxide (SPFGO) composite film-based organic light emitting Diode (OLED) and organic photovoltaic (OPV) performance for different SPFGO concentrations. There is a strong quenching of photoluminescence when MEH-PPV is doped with SPFGO, which means there is a strong transfer of electron and energy between MEH-PPV and SPFGO. Doping SPFGO in MEH-PPV can improve the performance of OLED at low concentration, and the performance will be the best when the concentration of SPFGO is 0.2%; however, the performance of OPV remains unchanged. The performance of OPV could be improved by high doping concentration of SPFGO, the performance will be the best when the concentration of SPFGO reaches 15%, and there is a quenching in the electroluminescence (EL) of OLED. As shown in the statistics of the experiment, SPFGO can increase the injectivity of carriers, and when the SPFGO is of low concentration, it can increase the luminous intensity of OLED and reduce the threshold voltage. SPFGO can act as an electron acceptor, and when the concentration of SPFGO is high, the exciton dissociation at MEH-PPV/SPFGO interface can be improved, and the performance of OPV can be also improved. Therefore, the concentration of SPFGO should be the main factor in adjusting the performance of OLED and OPV separately.
Congestion and efficiency in complex traffic and transportation networks
Authors: Xiao Yao  , Zheng Jian-Feng  ,   School of Traffic and Transportation, Beijing Jiaotong University, Beijing 100044, China;,   MOE Key Laboratory for Urban Transportation Complex Systems Theory and Technology, Beijing Jiaotong University, Beijing 100044, China
Published: December 2020

This paper investigates the congestion and efficiency in complex traffic and transportation networks. Effects of different distributions of capacity and origin-destination traffic demand on the degree of congestion and efficiency are explored in different network topologies including scale-free networks, random networks and small-world networks. According to the increase of average traffic demand, the transition from free flow state to congested state is analyzed. For easy comparison, we discuss the reciprocal of the congestion degree, which is defined as the network unobstructedness. A linear relation between the degree of unobstructedness and efficiency in different networks is uncovered, and the linear proportional coefficients are different in scale-free networks, random networks and small-world networks. These coefficients can also be used to describe the different transport performance in different networks.
The pitchfork bifurcation and vibrational resonance in a quintic oscillator
Authors: Yang Jian-Hua  , Liu Hou-Guang  , Cheng Gang  ,   School of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, China
Published: December 2020

The pitchfork bifurcation and vibrational resonance are investigated in this paper. Based on the method of separating slow motion from fast motion, the equivalent equation to the slow motion is obtained. Then, the pitchfork bifurcation is studied. The results show that the amplitude of the high-frequency signal can induce the subcritical pitchfork bifurcation, while both the frequency of the high-frequency signal and the value of the fractional-order can induce supercritical pitchfork bifurcation. The pattern of the vibrational resonance depends on the pitchfork bifurcation. The vibrational resonance presents double-resonance pattern when the pitchfork bifurcation occurs. Or else, the vibrational resonance presents single-resonance pattern. The analytical predications are in good agreement with the numerical calculation results, which verifies the validity of the theoretical results.
Study of vector mesons and its excited states
Authors: Wei Ke-Wei  , Chen Bing  , Wang Zhen-Yang  , Qi Jing-Juan  , Chen Xin-Yun  , Weng Ming-Hua  ,   College of Physics and Electrical Engineering, Anyang Normal University, Anyang 455000, China;,   Theoretical Physics Center for Sciences Facilities, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;,   College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China;,   Department of Physics and Electronic Information Engineering, Minjiang University, Fuzhou 350108, China
Published: December 2020

Based on the Regge phenomenology, we first study the mass relations for six mesons involving three flavors in one spin-parity multiplet. Using the examined mass relation, mass of the unobserved vector doubly heavy charm-bottom Bc*(13S1) is calculated. Masses of the unobserved radial excited vector (23S1) mesons and the orbital excited 13G5 meson nonet are given. Our predictions are discussed. We suggest searching Bc* near 6355 MeV. D(2600) and Ds1(2700) can be considered as candidates for nc(23S1 and sc(23S1) dominated states, respectively. We suggest searching B*(2S), Bs*(2S) and Bc*(2S) near 5812, 5917 and 6896 MeV, respectively. We suggest restudying 5(2350) near 2259 MeV, searching 5(13G5) near 2438 MeV and identifying 5(2250) as isoscalar member of 13G5 nonet. The results may be profoundly useful for the JP assignment of related states and the discovery of the unobserved excited mesons.
Factors influencing filling degree in nanoimprint lithography with pseudoplastic fluid
Authors: Xia Wei-Wei  , Zheng Guo-Heng  , Li Tian-Hao  , Liu Chao-Ran  , Li Dong-Xue  , Duan Zhi-Yong  ,   Physical Engineering College of Zhengzhou University, Zhengzhou 450001, China
Published: December 2020

As a novel development of semiconductor process, direct metallic patterning has the advantages of simple steps, low cost, etc. However, almost all transfer media are Newtonian fluids in traditional nanoimprint lithography. Newtonian fluid viscosity is constant. Too high a viscosity is adverse to filling the small space, and if viscosity is too low, it is harmful to solidify graphics. So an appropriate viscosity range that can both realize a high filling degree and benefit solidification is difficult to determine. Pseudoplastic fluid viscosity decreases with the increase of shear rate. The problem would be solved well when pseudoplastic fluid is used as a transfer medium. Synthesizing the advantages of direct metallic patterning and pseudoplastic fluid feature, a novel idea is put forward. The pseudoplastic metal nanofluids, which would be fabricated with metal nanoprticals, can take the place of transfer medium in nanoimprint lithography. Based on the finite element method, COMSOL software is used to compute the filling degree of pseudoplastic fluid, and the results are compared with those of Newtonian fluid under the same conditions. Factors, such as viscosity, imprinting speed, pressure, etc., which would affect filling degree, can be obtained from simulation results. These parameters provide a theoretical basis for designing technological process and fabricating pseudoplastic fluids in future work.
The single-direction energy transition model of molecular motor based on the control of adenosine triphosphate
Authors: Li Chen-Pu  , Han Ying-Rong  , Zhan Yong  , Xie Ge-Ying  , Hu Jin-Jiang  , Zhang Li-Gang  , Jia Li-Yun  ,   Department of Mathematics and Physics, Hebei Institute of Architecture Civil Engineering, Zhangjiakou, Hebei 075000, China;,   School of Science, Hebei University of Technology, Tianjin 300401, China
Published: December 2020

The dynamic principle of molecular motor transport in overdamped solution remains unclear. Starting from the transport characteristics and phenomenon of the molecular motor system, the single-direction energy transition model is established, which conforms to the Langevin equation, and the stochastic dynamics of molecular motors is analyzed by Monte Carlo simulations. Results show that with the right transition energy, molecular motors could take a stable stepping motion and effective transport by means of the environment noise, and the load force can weaken material transportation of the molecular motor system. The potential field between a molecular motor and its orbit can affect the magnitude of the velocity of motor, but cannot change the direction of the velocity, the direction of motion of the molecular motor therefore is adjusted by the transition energy of the motor. In addition, although the average velocity is not zero for different noise intensities, the efficient transport of a molecular motor system indicates that the system is selective for the noise intensity.
Design of ultrathin broadband perfect metamaterial absorber with low radar cross section
Authors: Li Si-Jia  , Cao Xiang-Yu  , Gao Jun  , Zheng Qiu-Rong  , Zhao Yi  , Yang Qun  ,   School of Information and Navigation, Air Force Engineering University, Xi’an 710077, China
Published: December 2020

We propose a method of designing ultrathin broadband perfect metamaterial absorber (PMA) which is based on the parameters of the cell. The bandwidth is enhanced via the method which combines the multilayer and multi-resonance in a layer. And it is not complex due to having no lumped elements in it, so it is easy to fabricate and apply. In order to illustrate the method, a double-layer perfect metamaterial absorber with three resonance peaks is designed using the above method. The equivalent circuit of the proposed absorber is analyzed so as to better understand the mechanism of the high absorption. By adjusting geometric parameters of the structure, we can obtain a polarization-insensitive and wide-incident-angle ultra-thin absorber. Simulated and experimental results show that the full-width at half-maximum is 14.1% when the thickness of the filer is only 0.01λ, and the bandwidth of-3 dBsm radar cross section reduction is 18.9%. At resonance, the reduction value may exceed 23 dBsm while the absorber has a good characteristic of RCS reduction at the boresight direction from-40° to +40°.
Flat-top Brillouin gain spectrum with a controllable bandwidth produceal from multiple-lines pump modulation in liquid-core optical fibers
Authors: Gao Wei  , Liu Sheng-Nan  , Bi Ya-Feng  , Hu Xiao-Bo  , Pu Shao-Zhi  , Zhao Hong  ,   Department of Optics Information Science and Technology, College of Applied Science, Harbin University of Science and Technology, Harbin 150080, China;,   Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, China
Published: December 2020

We present a method of achieving a flat-top Brillouin gain spectrum (BGS) with a controllable bandwidth based on multiple-lines pump modulation in a CS2/CCl4 mixture liquid-core optical fiber. The influences of the pump spectrum separation, the intensity of each spectrum line, and the mixing ratio of core liquid media on the BGS are theoretically investigated, and the conditions of producing the flat-top BGS with an adjustable bandwidth are obtained. Results show that 2–9 spectral lines are generated based on single-frequency and multifrequency modulation using an intensity or phase modulator. The flat-top BGS with bandwidths of 50 MHz–2 GHz are obtained by controlling spectrum separation, the intensity ratio of each spectral line and CS2 volume fraction. This method has advantages of convenient operation and wide bandwidth range. It can be applied in Brillouin amplification with high gain and low distortion, and hence satisfies the requirements of weak signal detection and slow light systems.
Analysis and experimental verification of the relation between Scholte wave velocity and sediment containing two-phase fluid properties
Authors: Han Qing-Bang  , Xu Shan  , Xie Zu-Feng  , Ge Rui  , Wang Xi  , Zhao Sheng-Yong  , Zhu Chang-Ping  ,   Hohai University IOT institute, Changzhou, Jiangsu 213022, China
Published: December 2020

Based on several ultrasonic suspension models, i.e. Urick, Urick-Ament, HT and Mcclements, the Scholte wave propagation characteristics are analyzed at the interface between sediment concentration two-phase fluid and porous medium solid. The interface wave propagation characteristic equation are found using the complex wave number equation given by the aforementioned four models. Relationships between Scholte velocity and the two-phase fluid properties, (e.g., dispersion, volume content, particle size) are discussed. Scholte wave propagation and signal are obtained by Comsol simulation. By using the time delay estimation method, it is found that the obtained Scholte wave velocity are in accord with that given in Urick-Ament and HT models.
Feasibility research on the method of rain rate detection based on space-earth link signals at 1–10 GHz
Authors: An Hao  , Yan Wei  , Zhao Xian-Bin  , Wang Shao-Bo  , Lü Hua-Ping  ,   College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101, China
Published: December 2020

Satellite signals across the space-earth link are always seriously affected by rain, inducing attenuation and depolarization. In this paper, two methods of estimating the rain rate are investigated based on the space-earth link signals in a frequency range of 1–10 GHz. Firstly, the effects of rain rate (R) on attenuation (A) and cross-polarization discrimination (XPD) are studied, according to the complex interaction between signals and raindrops. Then, two relevant models A-R and XPD-R are established, which are the key techniques to estimate the rain rate. The feasibilities of the above models are analyzed. In addition, their applicabilities at various frequencies, polarization and satellite elevations are also investigated systematically. The results show that for the space-earth link signal with horizontal or circular polarization and higher frequency, the A-R relation can be used to estimate the heavy rain; for signals with different frequencies and polarizations, XPD-R is suited to estimate various rain rates, especially in a frequency range of 1–50 mm·h-1; A-R and XPD-R are both applicable at different elevations. Moreover, the XPD-R relation is consistent with the prediction model of XPD proposed by ITU at 4–10 GHz. The results obtained in this work will play an important role in the future verification experiment, the nowcasting automatic detection of rain rate and global rain observations.
Study on the partial gating smart network camera for controlling strong light intensity based on DSP and liquid crystal
Authors: Tang Yuan-He  , Wu Yong  ,   Faculty of Science, Xi’an University of Technology, Xi’an 710048, China
Published: December 2020

Based on the electro-optical characteristics of the transmission-type liquid crystal (LC) and DSP (Digital Signal Processor, chip TMS320DM642) technology, a smart network camera system for partial gating strong light intensity is developed. An LC display driver is controlled by DSP to achieve light intensity transmittance of every single pixel in this system; the light intensity transmittance can be decreased by two orders of magnitude. In addition, the smart camera of video signal processed under a strong light can be transmitted through network transmission and real-time storage to PC by another DSP (chip TMS320DM6437). Thus the LC delay time is about 25.5 ms and the system circuit delay time is about 17 μs, while the storage hard disk capacity requires 8.648 Gbit in 24 h. Experimental images are taken by the prototype to shoot the simulated license plate illuminated by the strong light (greater than 2.2×105 lx). Results show that the imaging problems, viz the ordinary CCD camera may give partially overexposed images and cannot distinguish details under the strong light, are all solved and achieved a high dynamic range imaging by the prototype.
Investigation of the crystal and optical properties of ZnS thin films deposited at different temperature
Authors: Yu Tian-Yan  , Qin Yang  , Liu Ding-Quan  ,   Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
Published: December 2020

The crystal and optical properties of ZnS optical coatings deposited at different substrate temperatures are studied in this paper. It is indicated that the substrate temperature has an evident effect on the properties of ZnS films. The XRD varies with the temperature. With the increase of the temperature, the XRD of ZnS film exhibits an obvious (111) orientation. At the same time, ZnS films have different stabilities at different substrate temperatures. At 115 ℃ and 155 ℃, the stability gets worse but at 190 ℃ and 230 ℃, it gets better. The variation of the substrate temperature has also effect on the optical properties of ZnS film, such as optical constants and deposition coefficient. At higher temperatures (190 ℃ and 230 ℃), the refractive index is higher than at lower temperatures (115 ℃ and 155 ℃). But the deposition coefficient gets smaller. Optical constants of ZnS films are calculated at different temperature.
Study on physical model for strained Si MOSFET with hetero-polycrystalline SiGe gate
Authors: Wang Bin  , Zhang He-Ming  , Hu Hui-Yong  , Zhang Yu-Ming  , Song Jian-Jun  , Zhou Chun-Yu  , Li Yu-Chen  ,   Key Laboratory for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi’an 710071, China
Published: December 2020

A new strained Si MOSFET structure with hetero-polycrystalline SiGe gate was studied, which combines the advantages of “gate engineering” and “strain engineering”. The new structure improved the carrier transport efficiency, suppressed the short-channel effects (SCE), and enhanced the performance on the basis of strain. Then a physically modeling strategy such as quasi-2D surface potential of strong inversion, threshold voltage, and channel current was presented for the strained Si NMOSFET. Finally, the above model was computed and the results were analyzed.
Simulation of marine controlled-source electromagnetic response in horizontally layered transversely isotropic formation by using improved transmission line method
Authors: Wang Jian-Xun  , Wang Hong-Nian  , Zhou Jian-Mei  , Yang Shou-Wen  , Liu Xiao-Jun  , Yin Chang-Chun  ,   College of Electronic Science and Engineering, Jilin University, Changchun 130012, China;,   College of Physics, Jilin University, Changchun 130012, China;,   College of Geoexploration Science and Technology, Jilin University, Changchun 130026, China;,   Department of Physics, Nature Science College, Qiqihar University, Qiqihar 161006, China
Published: December 2020

In this paper, the two-dimensional Fourier transform and wave decomposition technique are used to transform Maxwell’s equation in transversely isotropic (TI) formation into two independent sets of transmission line equations about transverse magnetic (TM) wave and transverse electric (TE) wave. According to both transmission line theory and superposition principle, an improved transmission line method is advanced to simplify the computational process of TM wave and TE wave only by introducing the transmission line Green’s functions of the current source. Thus, the new algorithm and the new expressions of current source electromagnetic (EM) dyadic Green’s functions in frequency-wavenumber domain are established for realizing the efficient simulation of marine controlled-source electromagnetic (MCSEM) responses in the horizontally layered TI formation. On this base, the basic solutions of the transmission line Green’s functions and EM boundary conditions are utilized to derive the recursive formula of the generalized reflections and amplitudes of the TE and TM waves, and the analytic solutions of the Green’s functions in each bed are obtained. Then, by using Fourier inverse transform and Bessel integral formula, the MCSEM responses in frequency-spatial domain are expressed in the Sommerfeld integral form. A combination of the cubic spline interpolation with the Lommel integral is used to efficiently compute the MCSEM responses. Finally, we validate the modeling algorithm and investigate the influences of changes in operation frequency and anisotropic coefficient on the MCSEM response in the TI formation.
Full-field detection of polarization state based on multiplexing digital holography
Authors: Ma Jun  , Yuan Cao-Jin  , Feng Shao-Tong  , Nie Shou-Ping  ,   School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China;,   Department of Physics, Nanjing Normal University, Nanjing 210097, China
Published: December 2020

Based on digital holography recording system, it is proposed to use both polarization and angular multiplexing techniques to detect a polarization state. Reference beam is divided into two beams with orthogonal polarization directions and equal initial phases. And the beams interfere with the two orthogonal components of object wave respectively, which generates two holograms recorded in one frame. The use of angular multiplexing separates the two orthogonal components of object wave in the Fourier domain by respectively introducing carriers towards different directions. By numerical filtering, inverse Fourier transform and then diffraction calculation, complex amplitude of object wave can be obtained at different distances to the holograms. With the obtained complex amplitude, it is possible to work out both the Stokes parameters and Jones vector, which describe the polarization state of the object wave. The measuring of elliptical polarization state and the characterizing of polarization states at different locations on axis prove the validity of this real-time full-field detection method.