bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase-sensitive optical time-domain reflectometer based on bi-directional Raman amplification
Authors: Wang Jie  , Jia Xin-Hong  , Rao Yun-Jiang  , Wu Hui-Juan  ,   Key Laboratory of Optical Fiber Sensing and Communications, Ministry of Education, School of Communication and Information Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Published: December 2020

In this paper, we report on a distributed sensing system of phase-sensitive optical time-domain reflectometer (Φ-OTDR) based on bi-directional Raman amplification. With the bi-directional Raman amplification, the transmission loss of the optical fiber can be compensated efficiently. The experimental characterization of evenly detected signals along the whole sensing distance of 74 km with 20 m spatial resolution is successfully demonstrated, resulting in the longest distributed sensing system based phase-sensitive optical time-domain reflectometer reported so far, to the best of our knowledge. The influences of different incident powers and pump powers on Φ-OTDR are studied experimentally.
The comparisons between two retrieve algorithms for metamaterials
Authors: Ding Min  , Xue Hui  , Wu Bo  , Sun Bing-Bing  , Liu Zheng  , Huang Zhi-Xiang  , Wu Xian-Liang  ,   Key Laboratory of Intelligent Computing and Signal Processing, Ministryof Education, Anhui University, Hefei 230039, China;,   Department of Physics and Electronic Engineering, Hefei NormalUniversity, Hefei 230061, China
Published: December 2020

Extracting the equivalent parameters of the weak-coupling and strong-coupling fishnet structure metamaterial based on the traditional retrieval algorithm and the improved algorithm of Kramers-Kronig relations are proposed, respectively. A comparative analysis of the effectiveness and applicability of the two algorithms are also included. The theoretical analysis and numerical results show that the traditional retrieval algorithm can retrieve the equivalent parameters of the weak-coupling and strong-coupling cases of electromagnetic metamaterials accurately, but with high computational complexity. While the improved algorithm based on the Kramers-Kronig relations can reduce the computational complexity and extract the equivalent parameters only for the weak-coupling case of electromagnetic metamaterials. However, it is not suitable for the strong-coupling case which may disobey the continuity requirement of the Kramers-Kronig relations. The presented results may extend the equivalent medium theory and provide a theoretical reference for the design of new metamaterials.
Analyses of rigid-flexible coupling dynamic properties of a rotating internal cantilever beam
Authors: Fang Jian-Shi  , Zhang Ding-Guo  ,   School of Sciences, Nanjing University of Science and Technology, Nanjing 210094, China;,   School of Materials Engineering, Nanjing Institute of Technology, Nanjing 211167, China
Published: December 2020

The rigid-flexible coupling dynamic properties of an internal cantilever beam attached to a rotating hub are studied in this paper. Based on the accurate description of non-linear deformation of the flexible beam, the first-order approximation coupling model is derived from Hamilton theory and assumed mode method, taking into account the second-order coupling quantity of axial displacement caused by transverse displacement of the beam. The simplified first-order approximation coupling model which neglects the effect of axial deformation of a beam is presented. The simplified model is transformed into dimensionless form in which dimensionless parameters are identified. Firstly, the dynamic response of an internal cantilever beam is compared with that of an external cantilever beam, which are both in non-inertia system. Then, the stability of an internal cantilever beam is analyzed. Finally, the convergence of critical rotating speed of an internal cantilever beam is analyzed. Generally, it is pointed that an internal cantilever beam has a dynamic softening phenomenon, which is different from the dynamic stiffening phenomenon of an external cantilever beam. The critical ratio of the internal radius to the length of the beam for unconditional stability and the critical rotating speed of conditional stability of an internal cantilever beam are derived. When the first natural frequency decreases as the rotating speed increases, the dynamic system of the internal cantilever beam is conditionally stable. As the number of modes increases, the critical rotating speed of an internal cantilever beam decreases, and it has a convergent value.
Experimental study on the behaviors of femtosecond-laser-induced low-pressure N2 plasma
Authors: Liu Xiao-Liang  , Sun Shao-Hua  , Cao Yu  , Sun Ming-Ze  , Liu Qing-Cao  , Hu Bi-Tao  ,   School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
Published: December 2020

The spectra of N2 plasma induced by a femtosecond pulsed laser are studied experimentally at sub-atmospheric pressure. The results show that the spectra of laser-induced plasmas for all sample pressures are composed of continuous spectra and line spectra. As the sample pressure is reduced the intensities of continuous spectra undergo the transition from slow increase to rapid decrease; on the other hand, the intensities of N+ spectra increase significantly with the decrease of pressure. The spectra of N++ species are observed when the pressure is lower than 0.3 atm. The behaviors of the femtosecond laser propagation and energy absorption in N2 plasma at sub-atmospheric pressure are also given and the feature of the laser-induced plasma channel is briefly discussed. These results are helpful for better understanding the laser-induced plasma characteristics, especially provide the clue to the experimental measurement conditions for different charged species, which is useful for the future corresponding experimental research.
Analyses of heavy metals by soil using dual-pulsed laser induced breakdown spectroscopy
Authors: Du Chuang  , Gao Xun  , Shao Yan  , Song Xiao-Wei  , Zhao Zhen-Ming  , Hao Zuo-Qiang  , Lin Jing-Quan  ,   School of Science, Changchun University of Science and Technology, Changchun 130022, China
Published: December 2020

The heavy metal elements contained in soil samples which are collected from Changchun train station, CUST campus, South Lake and Jingyue Lake park are separately analyzed by using the orthogonal dual laser pulses induced breakdown spectroscopy (DP-LIBS). The elements Mn, Cr, Cu and Pb are qualitatively analyzed according to the LIBS spectral intensity. It is shown that the intensity of the spectrum is greatly enhanced by using the DP-LIBS and the enhancement is closely related to the delay time between the double pulses. Enhancement variation with delay time presents double-peak changing when 532 nm and 1064 nm laser pulse energies are 70 mJ and 100 mJ respectively. The enhancement of Mn I 406.4 nm is 2.75 at a delay time of 20 s and it is 2.4 at a delay time of 30 s when the second peak appears. The enhancement mechanism of orthogonal pre-ablation DP-LIBS is further discussed.
The experimental research of pinhole point backlight based on Shenguang-Ⅲ proto-type facility
Authors: Yan Ji  , Zheng Jian-Hua  , Chen Li  , Tu Shao-Yong  , Wei Min-Xi  , Yu Bo  , Liu Shen-Ye  , Jiang Shao-En  ,   Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
Published: December 2020

A new type of pinhole-assisted point backlighter developed and optimized based on experimental research performed on Shenguang-Ⅲ proto-type facility is presented. High quality images of tungsten micro wires and capsule are acquired with a 4.75 keV X-ray point source produced by 1600 J/1 ns/351 nm laser interaction with 3 μm Ti target. Detailed parameters of this backlighter are also obtained using a multiple diagnostic device. The results indicate that pinhole-assisted point-projection backlighter has advantages of high intensity and high spatial resolution, and can be widely used in high energy density physics research.
First-principles calculations of structural thermodynamic and mechanical properties of 5d transitional metal diborides
Authors: Zhao Li-Kai  , Zhao Er-Jun  , Wu Zhi-Jian  ,   College of Science, Inner Mongolia University of Technology, Hohhot 010051, China;,   State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
Published: December 2020

The structural, thermodynamic, mechanical and electronic properties of 5d transitional metal diborides TMB2 (TM=Hf-Au) are systematically investigated by first-principles within density functional theory. For each diboride, three structures are considered, i.e., AlB2, ReB2 and WB2 structure. The calculated lattice parameters are in good agreement with previous theoretical and experimental results. From the calculated formation enthalpy, thermodynamic stability of compounds is predicted and the formation enthalpy increases from HfB2 to AuB2. Among the considered structures, AlB2 structure is the most stable for HfB2 and TaB2; ReB2 structure is the most stable for WB2, ReB2, OsB2, IrB2 and AuB2; WB2 structure is the most stable for PtB2. The ReB2 in ReB2 structure has the largest shear modulus (295 GPa), and is the hardest compound, which is in agreement with previous theoretical and experimental results. The calculated density of states shows that they are all metallic. Their variation trends are discussed.
Micro-structural and resistive switching properties of vanadium oxide thin films
Authors: Wei Xiao-Ying  , Hu Ming  , Zhang Kai-Liang  , Wang Fang  , Liu Kai  ,   School of Electronics Information Engineering, Tianjin University, Tianjin 300072, China;,   Tianjin Key Laboratory of Film Electronic and Communication Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384, China
Published: December 2020

Vanadium oxide thin films are deposited on Cu/Ti/SiO2/Si by reactive sputtering at room temperature. The crystal structure, component and surface morphology of VOx film are characterized by X ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy, respectively. These investigations reveal that there is no obvious crystal orientation except weak V2O5 (101) and V2O3 (110) peaks, and the film contains VO2, V2O5, V2O3 and VO mixture phase. The surface particle size of the film is uniform with a root mean square roughness of 1 nm. The resistive switching properties of VOx thin film are tested by semiconductor device analyzer (Agilent B1500A). The I-V characteristics of the VOx memory cell reveal that the cell has low switch voltage (VSetVResetIReset) increases with current compliance increasing. The double-logarithmic plots of the I-V curve for the high and low resistance state show high configuration slope >1 and low resistance state slope=1. It is confirmed that the copper ion diffusion and the formation of conduction filaments may be the resistance switching mechanism of the VOx/Cu structure.
3D simulation of heavy ion induced charge collection of single event effects in SiGe heterojunction bipolar transistor
Authors: Zhang Jin-Xin  , Guo Hong-Xia  , Guo Qi  , Wen Lin  , Cui Jiang-Wei  , Xi Shan-Bin  , Wang Xin  , Deng Wei  ,   Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China;,   Xinjiang Key Laboratory of Electronic Information Materials and Devices, Urumqi 830011, China;,   Northwest Institution of Nuclear Technology, Xi’an 710024, China;,   University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

In this paper, we establish a three-dimensional numerical simulation model for SiGe heterojunction bipolar transistor by the technology computer aided design simulations. In the simulation we investigate the charge collection mechanism by heavy ion radiation in SiGe HBT technology. The results show that the charge collected by the terminals is a strong function of the ion striking position. The sensitive area of charge collection for each terminal is identified based on the analyses of the device structure and simulation results. For a normal strike within and around the area of the collector/substrate junction, most of the electrons and holes are collected by the collector and substrate terminals, respectively. For an ion strike between the shallow trench edges surrounding the emitter, the base collects a large quantity of charge, while the emitter collects a negligible quantity of charge.
Temperature dependent dielectric of aqueous NaCl solution at microwave frequency
Authors: Wang Feng  , Jia Guo-Zhu  , Liu Li  , Liu Feng-Hai  , Liang Wen-Hai  ,   College of Physics and Electronics Engineering, Sichuan NormalUniversity, Chengdu 610066, China
Published: December 2020

Dielectric properties of aqueous NaCl solution, which are dependent on temperature (293-353 K), with a concentration in a range of 0.001-0.5 mol/L at microwave frequencies ranging from 200 MHz to 6.25 GHz are studied experimentally. The results indicate that imaginary part decreases with frequency increasing, and tetrahedral structure of H2O and hydrogen bond of aqueous NaCl solution is broken by high temperature, leading to the decreasing of real part of dielectric. The loss angle tangent in solution obviously decreases in a low frequency zone at 353 K compared with that in pure water. Temperature window effect that complex dielectric increases or decreases with temperature varying at 2.45 GHz and 5.8 GHz, thereby leading to the oscillation of dissipation power in microwave heating process and the nonequilibrium distribution of temperature is also confirmed.
Adaptive synchronization and parameter identification for Lorenz chaotic system with stochastic perturbations
Authors: Zhu Da-Wei  , Tu Li-Lan  ,   Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430065, China
Published: December 2020

In this paper, Lorenz chaotic system with stochastic perturbation and unknown parameters is investigated, in which the stochastic perturbations is one-dimensional random process of the standard Wiener. Based on stochastic Lyapunov stability theory, It formula and adaptive control method combined with three adaptive control laws and two adaptive control laws respectively, two mean square Asymptotic adaptive synchronization standards are put forward theoretically. These new standards are in a simple form and easy to deal with. Moreover, with these standards, not only drive system with stochastic perturbations can be synchronized with the respond system, but also unknown parameters in the system can be identified. Finally, the Matlab numerical simulations confirm that the proposed results are correct and effective.
Theoretical study of structural stabilities of BiXO3 (X= Cr, Mn, Fe, Ni)
Authors: Luo Zui-Fen  , Chen Xing-Yuan  , Lin Shi-Yuan  , Zhao Yu-Jun  ,   Guizhou Minzu University, Polytechnic College, Guiyang 550025, China;,   Department of Applied Physics, South China University of Technology, Guangzhou 510640, China
Published: December 2020

The stable chemical potential phases of BiXO3 (X= Cr, Mn, Fe, Ni) are studied by density functional theory with the consideration of thermodynamics equilibrium conditions. It is found that the BiFeO3 and BiCrO3 have stable chemical potential regions and are expected to be synthesized, under thermodynamic equilibrium conditions. On the contrary, no stable regions are found for BiMnO3 and BiNiO3, indicating that they are hard to synthesize. Therefore the approaches to their preparation under non-thermodynamic equilibrium conditions should be considered.
Hydrogen storage capacity of lithium decorated B6 cluster
Authors: Ruan Wen  , Luo Wen-Lang  , Yu Xiao-Guang  , Xie An-Dong  , Wu Dong-Lan  ,   College of Mathematics and Physics, Jinggangshan University, Ji'an 343009, China
Published: December 2020

The structures and the hydrogen storage capacities of the B6 clusters and the lithium decorated B6 clusters are investigated by using the density functional theory. The results show that the hydrogen is adsorbed in the atomic form by chemical bonds in the three possible structures of the B6 cluster. The lithium atoms do not cluster on the surface of decorated B6 cluster. Every lithium atom, as hydrogen molecules are adsorbed on the surface of lithium atoms decorated B6 clusters, can adsorb several intact hydrogen molecules. Of the lithium decorated B6 clusters the B6 cage cluster which is decorated by two lithium atoms can most adsorb the intact hydrogen molecules. The calculated gravimetric density and the average adsorption energy of hydrogen molecule are 20.38% and 1.683 kcal/mol, respectively, which are suitable for reversible hydrogen storage under the ambient condition of the normal temperature and pressure.
The chiral asymmetry revealed by the Raman differential bond polarizability of (2R, 3R)-(-)- 2, 3-butanediol
Authors: Shen Hong-Xia  , Wu Guo-Zhen  , Wang Pei-Jie  ,   the College of Biology and Chemical Engineering, Jiaxing University, Jiaxing 314001, China;,   State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, TsinghuaUniversity, Beijing 100084, China;,   The Beijing Key Laboratory for Nano-Photonics and Nano-Structure, Department of Physics, Capital Normal University, Beijing 100048, China
Published: December 2020

The Raman optical activity (ROA) of (2R, 3R)-2, 3-butanediol is investigated through the intensities of Raman spectrum and ROA spectrum, bond polarizability and differential bond polarizability. In view of the two possible optimized structures, i.e., C1 and C2 group, we obtain the conclusion that ample information concerning the physical pictures of this chiral system does not depend on the two variant structures.Based on the analysis of bond polarizabilities, the charge moves from the periphery to the skeleton structure in the Raman relaxation process. The analysis of differential bond polarizabilities shows that the signs of differential bond polarizabilities on the both sides of the plane associated with the asymmetric C and H atoms are opposite. This means that the chiral asymmetry of this molecule is rather complete.Also, it is observed that bond polarizabilities for the symmetric modes are larger than for the antisymmetric modes, while for the differential bond polarizabilities, the situation is just reverse.
Density functional theory study of the adsorption of CO on Wn (n= 16) clusters
Authors: Zhang Xiu-Rong  , Wang Yang-Yang  , Li Wei-Jun  , Yuan Ai-Hua  ,   School of Mathematics and Physics, Jiangsu University of Science and Technology, Zhenjiang 212003, China;,   School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China;,   School of Biology and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
Published: December 2020

CO molecules adsorbed on the Wn clusters are systematically investigated by using density functional theory at the B3LYP/LANL2DZ level.The result indicates that the ground state structures of WnCO clusters are generated when CO molecules are adsorbed on Wn clusters or anionic cluster. We find that among the molecular adsorption states exists mainly the form of end-on type geometry, and that the bridge site adsorption type geometry plays a supplementary role. On the face, the adsorption is a non-dissociative adsorption. The CO bond length increases 0.1200.123 nm in WnCO cluster (compared with 0.116 nm in free CO molecule), which demonstrates that the CO molecules are activated. The stability analysis shows that W3CO and W5CO clusters are more stable than other clusters; natural bond orbital (NBO) analysis indicate that the interaction between W atom and CO molecule is primarily contributed by hybridization of molecular orbits within CO and 6s, 5d, 6p and 6d orbits of W atoms.
Statistical features of aerodynamic effective roughness length over heterogeneous terrain
Authors: Huang Jin  , Zhong Zhong  , Guo Wei-Dong  , Lu Wei  ,   Department of Basic Course, Nanjing Institute of Technology, Nanjing 211167, China;,   College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101, China;,   ICGCR, Nanjing University, Nanjing 210093, China
Published: December 2020

With a new scheme of effective roughness length for heterogeneous terrain, based on the atmospheric boundary layer Monin-Obukhov similarity theory as well as flux and mass conservation principles, the statistical features of effective roughness length and its sensitivity to atmospheric stratification stability and roughness step for three surface category case are investigated. The results show that the effective roughness length is greater than the area-weighted logarithmic average one and the effective drag coefficient is more than 10% greater than the average one in most cases. The effective roughness length is much more sensitive to the roughness step, though it is dependent on the atmospheric stratification stability, and the relative percentage of effective roughness length and the effective drag coefficient will be 4 times and 3 times, respectively, for the double roughness step case. Therefore, the area-weighted average roughness length should be replaced by the effective one when the surface heterogeneity is considered in numerical models, which can represent the integrated effect of heterogeneous terrain.
High power microwave breakdown in gas using the fluid model with non-equilibrium electron energy distribution function
Authors: Zhao Peng-Cheng  , Liao Cheng  , Yang Dang  , Zhong Xuan-Ming  , Lin Wen-Bin  ,   Institute of Electromagnetics, Southwest Jiaotong University, Chengdu 610031, China
Published: December 2020

The electron energy distribution function (EEDF) is usually assumed to be of the Maxwellian distribution in the fluid model in the simulation of high power microwave breakdown in gas. However, this assumption may lead to some large errors in the simulations. In this paper we compute the non-equilibrium EEDF via solving the Boltzmann equation directly, and incorporate it into the fluid model for argon breakdown. Numerical simulations show that the breakdown time obtained by the fluid model with the non-equilibrium EEDF accords well with the Particle-in-cell-Monte Carlo collision simulation result, while the Maxwellian EEDF has higher energy tail and results in faster breakdown time at low mean electron energy. Based on the non-equilibrium EEDF, the dependence of the breakdown threshold on the pressure predicted by the fluid model accord well with the argon breakdown experimental result.
Effect of wall secondary electron emission on the characteristics of double sheath near the dielectric wall in Hall thruster
Authors: Qing Shao-Wei  , E Peng  , Duan Ping  ,   Institute of Power Engineering, Chongqing University, Chongqing 400044, China;,   Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001, China;,   Department of Physics, Dalian Maritime University, Dalian 116026, China
Published: December 2020

To further reveal the characteristics of sheath near the dielectric wall in Hall thruster discharge channel, a one-dimensional fluid sheath model combined with the velocity distribution function of electron emitted from wall is used to study the influence of secondary electron emission yield (SEEy) σ on the characteristics of double sheath near wall. Analytic results show that because of the contribution of secondary electron flux to the density of sheath electron, the sheath presents single-layer positive ion sheath formation when σ is lower than a critical SEEy σdc, and also presents double-layers formation that joins with positive ion sheath and electron sheath when σ>σdc. However, when σ further increases to 0.999, the sheath presents the formation of three-layers that are alternated by positive ion sheath, electron sheath and positive ion sheath. Numerical results also indicate that with the increase of σ, the joining point between positive ion sheath and electron sheath moves away from wall, and the thickness of electron sheath increases obviously.
Recent progress in preparation of material and device of two-dimensional MoS2
Authors: Lai Zhan-Ping  ,   Institute of China Electronics Technology Group Corporation, Tianjin 300220, China
Published: December 2020

After several decade developments the critical dimension of an integrated circuit will reach its limit value in the next 10-15 years, and the substitute materials been to be researched. Graphene has beed considered the most likely candidate, however, pristine graphene does not have a bandgap, a property that is essential for many application, including transistors. The two-dimensional layer of molybdenum disulfide (MoS2) has recently attracted much attention due to its excellent semiconductor property and potential applications in nanoelectronics. The device preparation, two-dimensional material research and property analysis of MoS2 are summarized and the trend for future research on large sigle-layer MoS2 crystal is presented.
Influnce of heat treatment on the structure and optical properties of glow discharge polymer films
Authors: Jia Xiao-Qin  , He Zhi-Bing  , Niu Zhon-Cai  , He Xiao-Shan  , Wei Jian-Jun  , Li Rui  , Du Kai  ,   Sichuan University, Institute of Atomic and Molecular Physics, Chengdu 610065, China;,   The Centre of Laser Fusion Research, China Academy of Engineering Physics, Mianyang 621900, China
Published: December 2020

The glow discharge polymer (GDP) films each with a thickness of about 5 m are deposited by low-pressure plasma polymer apparatus. The GDP films are heat-treated at different tempertures of 280, 300, 320 and 340 ℃ in Ar atmosphere. The influence of heat treatment on the structure of GDP film is characterized by FT-IR. The optical transparency and optical band of GDP film are investigated by UV-VIS spectrum. The results show that with temperature increasing, the relative content of CH3 decreases, while the relative content values of CH2 and CH increase. The H content in GDP film decreases. The optical band gap decreases, and the transmittance in a range of more than 600nm decreases too.
Gas-sensing properties at room temperature for the sensors based on tungsten oxide thin films sputtered on n-type ordered porous silicon
Authors: Hu Ming  , Liu Qing-Lin  , Jia Ding-Li  , Li Ming-Da  ,   School of Electronic Information Engineering, Tianjin University, Tianjin 300072, China
Published: December 2020

n-type porous silicons are prepared by the electrochemical corrosion method, on which tungsten oxide thin films with different thickness values are sputtered using DC reactive magnetron sputtering. The structures of ordered porous silicons and tungsten oxide thin films are characterized using field emission scanning electron microscope, which show that the pores are pillared and ordered and the thin films cover the porous layer loosely with many pores open to ambient air. The X-ray diffraction characterization indicates that the lattice structure of tungsten oxide thin film is mainly triclinic polycrystalline. The gas-sensing properties at room temperature for both ordered porous silicon and composite structure are studied, which indicate that the latter is much more sensitive to nitrogen dioxide than the former. And there is a critical spurting time of WO3 thin film, which in our case is 10 min. The sensing mechanism of composite structure is discussed and the probable explanation for the improvement of sensitivity to NO2 is the formation of hetero-junctions between the ordered porous silicon layer and the WO3 thin film. In addition, there exists an inversion layer on the surface of the WO3 thin film, which causes the anomalous resistance to change during the gas sensing measurements.
Effective response to external DC and AC electric field in nonlinear cylindrical coated composite
Authors: Li Qian-Qian  , Chen Xiao-Gang  , Bao Shu-Hong  , Guo Jun-Ming  , Zhai Li-Li  ,   College of Science, Inner Mongolia University of Technology, Hohhot 010051, China
Published: December 2020

By using the perturbation method, an effective nonlinear direct current (DC) and alternating current (AC) response of nonlinear composites with cylindrical coated inclusions randomly embedded in a host medium is studied under the action of an external electric field Ea=E0 + E1 sinωt+E3 sin3ωt with different amplitudes and frequencies. The local potentials of composite at all harmonics are given in the inclusion core, the coated layer and the host regions. All effective nonlinear responses of composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the cylindrical coated inclusions in a dilute limit.
Bonding-antibonding ground state transition in coupled quantum dots
Authors: Tang Nai-Yun  ,   Department of Electronic Science and Technology, Shanghai University of Electric Power Shanghai 200090, China
Published: December 2020

The two lowest single-particle hole states in two vertically coupled quntum dots (CQDs) are investigated by using the six-band KP model. A bonding-antibonding ground-state transition is observed with interdot distance increasing. This result is counterintuitive, for the antibonding molecular ground state has never been observed in natural diatomic molecules. By comparing the wavafunction component of hole, we verify that the reordering of bonding and antibonding orbitals with interdot distance increasing is caused by spin-orbit interaction of holes.
p-ZnO thin film/n-Si heterojunction light-emitting diode fabricated by chemical vapor deposition and its characterization
Authors: Feng Qiu-Ju  , Jiang Jun-Yan  , Tang Kai  , Lü Jia-Yin  , Liu Yang  , Li Rong  , Guo Hui-Ying  , Xu Kun  , Song Zhe  , Li Meng-Ke  ,   School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China
Published: December 2020

The Sb-doped ZnO film/n-Si heterojunction is synthesized by simple chemical vapor deposition method. The quality of crystal and surface morphology of Sb-doped ZnO film are improved after annealing at 800 ℃, which exhibits effective p-type conductivity with a hole concentration of 9.56× 1017 cm-3. The properties of the p-ZnO/n-Si heterojunction photoelectric device are investigated. The resuets show that this device has good rectifier characteristics with a positive open electric of 4.0 V, and a reverse breakdown voltage of 9.5 V. The electroluminescent is realized at room temperature under the condition of forward current 45 mA. These results also confirm that the high-quality ZnO film can be prepared by the simple chemical vapor deposition method, which opens the way for simple preparation of materials applied to ZnO based opto-electronic device.
Hard X-ray measurement for indirect-driven imploding by chemical vapor deposited diamond detectors
Authors: Yu Bo  , Chen Bo-Lun  , Hou Li-Fei  , Su Ming  , Huang Tian-Xuan  , Liu Shen-Ye  ,   Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
Published: December 2020

The diamond detector is used to diagnose X-ray and has the advantages of fast response, high sensitivity, large dynamic range, flat response, high breakdown field, and outstanding radiation hardness. The X-ray diamond detector with a metal-diamond-metal structur is developed, in which the optical grade diamond is synthesized by chemical vapor deposition (CVD) method. Through the calibration of response time on the pulse laser of 8 ps width, the full width at half maximum of the CVD diamond detector is 444 ps, the rise time of the detector is 175 ps, and the lifetime of the carrier is 285 ps. The detectors are used to measure the hard X-ray for the imploding experiment on SGIII-prototype equipment. The results indicate that the measured hard X-ray flux is produced mainly by laser and target imploding, and the peak signal is in direct proportion to the laser energy and in inverse proportion to the CH thickness of target.
Influence of working pressure on the state of H2/C4H8 glowing discharge plasma
Authors: Li Rui  , He Zhi-Bing  , Yang Xiang-Dong  , He Xiao-Shan  , Niu Zhong-Cai  , Jia Xiao-Qin  ,   Centre of Laser Fusion Research, China Academy of Engineering Physics, Mianyang 621900, China;,   Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
Published: December 2020

The variations of the main positive ion components and their energies for the plasma of H2/C4H8 gas mixture under different working pressures are investigated using the glow discharge technique and plasma mass spectrometry diagnostic method, and the effects of work pressure on both the dissociation mechanism of the mixed gas H2/C4H8 and the forming process of the main positive are analyzed. The results show that both the intensity and energy of the C-H segment ions in H2/C4H8 plasma decrease with pressure increasing. The relative concentration of m/e 41(C3H5+) reaches a maximum when work pressure is 5 Pa. And when the pressure is 10 Pa, the relative concentration of m/e 39(C3H3+) is largest; when the pressures are 15 Pa and 20 Pa, the relative concentration of m/e 29 (C2H5+) is highest; when the pressure is 25 Pa, the relative concentration of m/e 57(C4H9+) is biggest. The component and its energy distribution of H2/C4H8 plasma are qualitatively analyzed. The results will serve as a reference to the optimization of parameters for glow plasma polymer coatings.
Electronic conductivity effective masses along arbitrary directional channel in uniaxial strained Si(001)
Authors: Jin Zhao  , Qiao Li-Ping  , Guo Chen  , Wang Jiang-An  , Richard C. Liu  ,   School of Information Engineering, Chang'an University, Xi'an 710064, China;,   Key Laboratory for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China;,   University of Houston, Houston, Texas, USA
Published: December 2020

Electronic conductivity effective mass is one of the key parameters studing electron mobility enhancement in unixial strained Si material. Its in-depth study has the significant theoretical and practical values. In this paper, we first establish the E-k relation for conduction band in a unixial strained Si material. And the model of electronic conductivity effective mass along an arbitrary directional channel in the uniaxial strained Si (001) is obtained. Our concluding results are described as follows. 1) Tensile stress should be used to enhance electron mobility for unixial trained Si. 2) In the case of tensile stress application, both [110]/(001) and [100]/(001) directions are the desirable ones from the evaluation of electronic conductivity effective mass. And [110]/(001) direction should be preferable when the density of state effective mass is taken into consideration. 3) If [100] direction becomes the channel direction under [110]/(001) uniaxial strain, the further electron mobility enhancement will occur. The results above can provide valuable reference for the conduction channel design related to stress and orientation in the strained Si nMOS device.
Numerical modeling of the signal transmission by cables and electromagnetic coupling for logging while drilling
Authors: Zhu Ke-Bin  , Nie Zai-Ping  , Sun Xiang-Yang  ,   School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Published: December 2020

Lack of efficiency in transmitting logging signals has long been one of the crucial problems for the development of logging while drilling. This study aims to address this issue by using the advanced scheme for logging while drilling signal transmission, proposed by NovatekTM. The main points of the study focus on electromagnetic coupling between two adjacent pipes and the signal transmission in coaxial cables imbedded in drilling pipes. According to the axial symmetry of the electromagnetic coupling structure, the numerical mode matching is used to establish the numerical model for it. Through simulation analysis which is based on the numerical modeling of the electromagnetic coupling structure, we analyze how various parameters of the structure influence the coupling, obtain some significant conclusions, and optimize the coupling structure. The conclusions can be used to guide optimization design of coupling structure between the drill-pipe for signal transmission in logging while drilling. In addition, the rectangular transmission line whose characteristic impedance is 50 Ω is designed for the cable imbedded in the drill pipe, and the attenuation is calculated. Finally, simulation and experiment are performed for one unit of the pipeline. The results are in agreement with each other, thereby showing the good transmission performance.
Hawking radiation from the dynamical spherical symmetrically Einstein-Yang-Mills-Chern-Simons black hole
Authors: Yang Shu-Zheng  , Lin Kai  ,   Institute of Theoretical Physics, China West Normal University, Nanchong 637002, China;,   Department of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China
Published: December 2020

Using Hamilton-Jacobi method, the Hawking tunneling radiation and temperature are investigated near the event horizon of the Einstein-Yang-Mills-Chern-Simons black hole. The results show that the temperature and tunneling rate depend on the charge and horizon of black holes, and the conclusion is significant for investigating other dynamical black holes. What is more, we also prove that this method can be used to study Hawking radiation in the scalar, vector, Dirac field and gravitational wave cases.
Cellular automaton simulation of muti-lane traffic flow including emergency vehicle
Authors: Zhao Han-Tao  , Mao Hong-Yan  ,   School of Automotive Engineering, Harbin Institute of Technology, Weihai 264209, China;,   Library of Harbin Institute of Technology, Weihai 264209, China
Published: December 2020

Based on the analysis of urban road traffic flow affected by emergency vehicle, a muti-lane cellular automaton model is established. Three characteristic variables are introduced to modify the lane change rules, including the give-way state variable, the affected areas of police siren and the safe distance for mandatory lane change. Numerical simulation results indicate that lane number and hybrid vehicle scale factor have a great influence on vehicle speed and lane change number in low-density range. And the parameter setting for affected areas of police siren changes the lane change number within a certain range. Meanwhile, the parameter of safe distance for mandatory lane change mainly affects emergency vehicle speed and lane change number. The study indicates that the appearance of emergency vehicle interferences with traffic flow of lower density obviously, and the proposed parameters make cellular automaton model closer to the actual traffic scenarios under emergency conditions.
Chaotic forecasting of natural circulation flow instabilities under rolling motion based on lyapunov exponents
Authors: Zhang Wen-Chao  , Tan Si-Chao  , Gao Pu-Zhen  ,   Harbin Engineering University, National Defense Key Subject Laboratory for Nuclear Safety and Simulation Technology, Harbin 150001, China
Published: December 2020

The chaotic forecasting of irregular complex flow oscillation of natural circulation flow instabilities under rolling motion condition based on the largest Lyapunov exponents is performed. The correlation dimension, Kolmogorov entropy and the largest Lyapunov exponent are determined based on the phase space reconstruction theory of experimental data. On the premise that the irregular complex flow oscillation is confirmed to own chaos characteristic, the chaotic forecasting of the irregular complex flow oscillation is carried out by calculating the largest Lyapunov exponent. A comparisons between the prediction results and experimental data indicates that the chaotic forecasting based on the largest Lyapunov exponent is an effective way of producing those two-phase natural circulation flow instabilities. Meanwhile, the maximum predictable scale of chaotic flow instability is determined and a way of dynamic forecasting to monitor flow oscillation is presented. The method employed here provides a new method of studying the complex two-phase flow instabilities.
Theoretical design and experiment study of sub-wavelength antireflective micropyramid structures on THz emitters
Authors: Hu Xiao-Kun  , Li Jiang  , Li Xian  , Chen Yun-Hui  , Li Yan-Feng  , Chai Lu  , Wang Qing-Yue  ,   Ultrafast Laser Laboratory, College of Precision Instrument and Optoelectronics Engineering, Key Laboratory of Optelectronic Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China;,   State Key Laboratory of Precision Measuring Technology and Instruments, College of Precision Instrument and Optoelectronics Engineering, Centre of MicroNano Manufacturing Technology, Tianjin University, Tianjin 300072, China
Published: December 2020

Nonlinear crystals commonly used in optical rectification for the generation of terahertz (THz) radiation have high refractive indices in the THz frequency range, and thus Fresnel reflection at the crystal-air output surface causes a large part of the generated THz wave to be reflected back into the crystals. Here we report on the design and experimental study of sub-wavelength antireflective micropyramid structures on GaP crystals. Effective medium theory is used to demonstrate the enhancement of THz output by the antireflective micropyramid structures, and further to design the antireflective structures at different frequencies. Several micropyramid structures are fabricated on the output surface of GaP crystals by micromachining, and the correlation between the THz output enhancement and the structure parameters is verified. The agreement between theory and experiment shows that our methodology is applicable to other THz emitters based on optical rectification.
The research of polarized information detection for photo-elastic modulator-based imaging spectropolarimeter
Authors: Chen You-Hua  , Wang Zhao-Ba  , Wang Zhi-Bin  , Zhang Rui  , Wang Yan-Chao  , Wang Guan-Jun  ,   Key Laboratory of Instrumentation Science and Dynamic Measurement, North University of China, Taiyuan 030051, China;,   School of Information and Communication Engineering, North University of China, Taiyuan 030051, China;,   Engineering Technology Research Center of Shanxi Province for Opto-Electronic Information and Instrument, North University of China, Taiyuan 030051, China
Published: December 2020

A new method of polarization modulation based triple-photoelastic-modulator (triple-PEM) is proposed as an key component of photo-elastic modulator-based imaging spectro-polarimeter (PEM-ISP) combined with acousto optic tunable filter. The basic principles of PEM-ISP and triple-PEM-based differential frequency polarization modulation are described, that is, the tandem PEMs are operated as an electro-optic circular retardance modulator in a high-performance reflective imaging system. Operating the PEMs at slightly different resonant frequencies generates a differential signal that modulates the polarized component of the incident light at a much lower heterodyne frequency. Then the basic equations for polarization measurement is derived by analyzing and calculating its Muller matrix. The simulation and experiments verify the feasibility and accuracy of polarization measurement by triple-PEM-based differential frequency polarization modulation. Finally, we analyze the influences of the setting of integral step and sampling interval of the detector polarization measurement, and a preliminary error analyses of field angle, phase retardation amplitude etc are also be carried out. The result shows that the measurement error of DoLP is less than 0.6% when the phase retardation error is 1%. This work provides the necessary theoretical basis for remote sensing of new PEM-ISP and for engineering implementation of Stokes parametric inversion.
Study of Au-Ag alloy film based infrared surface plasmon resonance sensors
Authors: Zhang Zhe  , Liu Qian  , Qi Zhi-Mei  ,   State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China
Published: December 2020

Au-Ag alloy films deposited on the glass substrates are used, for the first time, as a wavelength-interrogated near infrared surface plasmon resonance (SPR) sensor. The values of resonance wavelength (λR) of the sensor at different angles of incidence are determined by absorptiometry and its refractive-index (RI) sensitivity is investigated using aqueous glucose solutions as the standard RI samples. As the incident angle increases from 7.5° to 9.5°, the SPR absorption peak shifts from λR = 1215 nm to 767.7 nm, the full width at half magnitude (FWHM) of the peak reduces from 292.8 nm to 131.4 nm, and the RI sensitivity decreases from 35648.3 nm/RIU down to 9363.6 nm/RIU. At the same initial λR, the SPR sensor with the Au-Ag alloy film shows a higher sensitivity than that with the pure Au film (S = 29793.9 nm/RIU at λR=1215 nm with a pure Au film). Adsorption of bovine serum album molecules from the aqueous solution of 1 μmol/L protein results in a redshift of ΔλR = 12.1 nm with the Au-Ag alloy film and ΔλR=9.5 nm with the pure Au film. The experimental data also indicate that the FWHM of the SPR absorption peak with the Au-Ag alloy film is larger than that at the same λR with the pure Au film, leading to a lower spectral resolution than that of the latter.
First-principles study of LuI3 scintillator
Authors: Deng Jiao-Jiao  , Liu Bo  , Gu Mu  ,   Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, Department of Physics, Tongji University, Shanghai 200092, China
Published: December 2020

We use first-principles calculation with pseudo-potential and plane wave method to study the electronic structure of LuI3. Exchange and correlation are treated in the local density approximation based on the density functional theory. The results show that the narrow bands with a width of about 0.2 eV near -4.4 eV are dominated by the 4f bands of Lu. Valence bands are located between -3.55 eV and 0 eV and mainly from p bands of I. Conduction bands are located between 2.44 eV and 12.35 eV and mainly from d bands of Lu, as well as from s bands of Lu. The peaks which appear at -3.46 eV of the s states of Lu, f states of Lu and p states of I show the strong interaction between the Lu and I.
Study on ro-vibrational excitation cross sections of Ne-HF
Authors: Xu Mei  , Wang Xiao-Lu  , Linghu Rong-Feng  , Yang Xiang-Dong  ,   School of Physics and Electronic Science, Guizhou Normal University, Guiyang 550001, China;,   School of Physics and Electronic Science, Guizhou Normal College, Guiyang 550018, China;,   Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
Published: December 2020

In this paper, the QCISD(T) method and aug-cc-pVTZ basic set are used to calculate the interactional potential of Ne atom and halogen hydride molecule HF, in which Boys and Bernardi's full counterpoise method is employed to eliminate the basis set superposition error. After obtaining the interactional potential energy data in eleven directions for He-HF, the symmetric potential V0 and the anisotropic potentials V1, V2, V3, etc. of the system are derived, by using Huxley function fitting, so as to describe well the He-HF potential energy surface. Finally, the close-coupling method is used to calculate the total collision excitation cross section, elastic partial wave cross section and inelastic elastic partial wave cross section.