bluuebunny/crossref_metadata_2025 huggingface dataset:
The entanglement dynamics of two entangled atoms in the dissipative cavity
Authors: Jiang Chun-Lei  , Fang Mao-Fa  , Wu Zhen-Zhen  ,   湖南师范大学物理与信息科学学院,长沙  410081
Published: December 2020

In this paper, we investigate the entanglement dynamics of two entangled two-level atoms interacting with a single-mode field in a dissipative cavity. The results show that the evolution properties of the entanglement degree of two entangled atoms depend on the initial atomic entanglement degree and form, the average photon number of the cavity field, and the cavity leakage rate. When the atoms are initially in a particular entangled state, the degree of entanglement can be amplified and not influenced by the dissipation of the cavity field.
Resonant tunneling of acoustic waves in 1D phononic crystal
Authors: Wang Wen-Gang  , Liu Zheng-You  , Zhao De-Gang  , Ke Man-Zhu  ,   武汉大学物理科学与技术学院，武汉  430072
Published: December 2020

We investigated theoretically and experimentally the acoustic waves tunneling and resonant-tunneling through one-dimensional phononic crystals within the frequency gap. The phononic crystal consists of parallel and periodically arrayed plastic plates immersed in water. Acoustic tunneling was observed for this single crystal structure at frequencies inside the band gaps. By slightly increasing the separation of the two plates in the middle, a double-crystal structure forms, which allows acoustic waves to resonantly tunnel through it, with transmission peaks observed inside the band gaps. At resonance, the measured group time is large, while off resonance very fast group velocity is found.
Three-dimensional numerical simulation of thermosolutal convection in enclosures using lattice Boltzmann method
Authors: Lu Yu-Hua  , Zhan Jie-Min  ,   中山大学应用力学与工程系，广州  510275
Published: December 2020

Lattice Boltzmann method of two-and three-dimensional thermosolutal convection is investigated in this paper. Lattice Boltzmann method with multiple components was applied to simulate two-dimensional thermosolutal convection flow on a square cavity. The numerical results agree well with those of high order finite difference method. It shows that the numerical scheme is efficient. Therefore the lattice Boltzmann method is extended to investigate three-dimensional thermosolutal convection flow in cubic cavity. The comparison between the proposed lattice Boltzmann method and a finite difference method shows a satisfactory agreement. The limitation of the lattice Boltzmann model in the double-diffusive convection is discussed.
The collapse and rebound of laser-induced cavitation bubble in viscous fluid
Authors: Zhao Rui  , Xu Rong-Qing  , Shen Zhong-Hua  , Lu Jian  , Ni Xiao-Wu  ,   (1)江苏科技大学电子信息学院，镇江  212003; (2)南京理工大学应用物理系，南京  210094
Published: December 2020

The oscillation property of a laser-induced cavitation bubble in a viscous fluid is investigated by a sensitive fiber-optic sensor based on optical beam deflection. The temporal and spatial evolutions of the bubble wall during the expansion and collapse are traced according to sequential waveforms induced by the bubble oscillation. Both the maximum and minimum bubble radii at each oscillation cycle are determined by experiment. Further, in combination with the theoretical analysis and numerical calculation, the variation of the maximum and minimum radii during oscillation and life-time of the bubble in different viscous fluids is obtained. The experimental results indicate that the liquid viscosity has an obvious influence on the bubble oscillation; larger viscosity makes the bubble contract more slowly, and the corresponding minimum radius and the bubble life-time become larger and longer, while the maximum radius is smaller.
Molecular dynamics study the effect of the ratio Ca/Al on CaO-Al2O3-SiO2 structure
Authors: Zhu Cai-Zhen  , Zhang Pei-Xin  , Xu Qi-Ming  , Liu Jian-Hong  , Ren Xiang-Zhong  , Zhang Qian-Ling  , Hong Wei-Liang  , Li Lin-Lin  ,   (1)深圳大学师范学院化学系，深圳  518060; (2)深圳大学师范学院化学系，深圳  518060；西安建筑科技大学材料学与工程学院，西安  710055; (3)西安建筑科技大学材料学与工程学院，西安  710055
Published: December 2020

The microstructure of CaO-Al2O3-SiO2(CAS)glass system is studied by molecular dynamics method.When Ca/Al equals to 1/2,which is called tectosilicate glass system,CAS is not a totally full network as conventional theories,but with some Non-Bridging Oxygen(NBO).The theoretical result proves Stebins's experimental conclusion.The result also reveals that when the ratio of Ca/Al is greater than 1/2 Al is preferred inserting in polymerized network to the end of polymerized network,when the ratio of Ca/Al is less than 1/2,the situationis is contrary.The “aluminium avoidance” principle believes that Al—O—Al linkages are energetically less favorable than Al—O—Si linkages in CAS glass system.However when the ratio of Ca/Al alters down across 1/2,there are some Al—O—Si linkages change to Al—O—Al and Si—O—Si linkages.
Structure and spectrum of the novel laser crystal Yb:KY(WO4)2
Authors: Wang Ying-Wei  , Wang Zi-Dong  , Cheng Hao-Bo  ,   (1)北京科技大学材料科学与工程学院，北京  100083; (2)北京理工大学信息科学技术学院，北京  100081
Published: December 2020

The selection of the flux and the design of the proper process are the key factors for the growth of Yb：KY(WO4)2 laser crystal. Yb：KY(WO4)2 crystal is grown by top seeded solvent growth (TSSG) method using K2W2O7 as a suitable flux. On the basis of TG-DTA, which has two obvious absorption peaks at 1045℃ and 1010℃, the Yb：KY(WO4)2 crystal's melting point is 1045℃, phase transition point from tetragonal system to monoclinic system is at 1040℃. Analyzing the X-ray diffraction spectrum of Yb：KY(WO4)2 crystal powder sample, we can conclude that the β-Yb：KY(WO4)2 crystal is of monoclinic system, and C2/c space group. The Yb：KY(WO4)2 crystals structure forms from the WO6 octahedra joined by WOOW double oxygen bridges and WOW single bridges. The IR and Raman spectra showed, the atom group WO6 has flex vibrations at 931cm-1，925cm-1, 891cm-1 and 840cm-1, and bend vibrations at 395cm-1，369cm-1，346cm-1 and 312cm-1, the WOOW double oxygen bridge has vibrations at 901cm-1, 759cm-1, 686cm-1, 435cm-1, 496cm-1 and 298cm-1, and the WOW single bridges has vibrations at 809cm-1, 525cm-1 and 235cm-1. At room temperature, the absorption peaks are at 940nm and 980nm the emission peaks are at 989nm—1030nm.
Electronic transport properties of single-wall carbon nanotube with pentagon-heptagon-pair defect
Authors: Zeng Hui  , Hu Hui-Fang  , Wei Jian-Wei  , Xie Fang  , Peng Ping  ,   (1)湖南大学材料科学与工程学院，长沙  410082; (2)湖南大学应用物理系，长沙  410082
Published: December 2020

Using the density-functional theory in combination with nonequilibrium Green's function technique, we studied the densities of states and transport properties of the(7，0)—(8，0)and(8，0)—(9，0)single-wall carbon-nanotube heterojunctions containing one pentagon-heptagon-pair (5/7) topological defect. The result suggests that the effect of pentagon-heptagon-pairs (5/7) topological defects on carbon nanotubes is remarkable.In addition, the heterojunctions constituted by different types of carbon nanotubes also have different characteristics.
Synthesis and thermoelectric properties of the Sm and Ce multiple doping skutterudites
Authors: Liu Tao-Xiang  , Tang Xin-Feng  , Li Han  , Song Chen  , Yang Xiu-Li  , Zhang Qing-Jie  ,   武汉理工大学材料复合新技术国家重点实验室，武汉  430070
Published: December 2020

Multiple-doped skutterudites SmmCenFe1.5Co2.5Sb12 were prepared by melting and spark plasma sintering method, and the effects of doping atoms Sm and Ce on the thermoelectric properties of these compounds were investigated. For p-type SmmCenFe1.5Co2.5Sb12, with the Sm and Ce multiple-doping amount increasing, the electrical conductivity and the thermal conductivity decrease and the Seebeck coefficient increases. When the doping amount is similar, in comparison with the Sm or Ce doping, the Sm and Ce multiple-doping can lower the thermal conductivity of skutterudites 10%—40%. At 775K, the ZTmax value of 0.84 was obtained for Sm0.22Ce0.20Fe154Co2.46Sb11.89.
Magnetic and thermodynamic properties of the mixed-spin antiferromagnet Y2BaNiO5
Authors: Kong Hong-Yan  , Zhang Lin  , Song Yun  ,   (1)宝鸡文理学院物理系非线性物理研究所，宝鸡  721007; (2)北京师范大学物理系，北京  100875
Published: December 2020

In this paper, within the frame of Green's function theory, we study the magnetic and thermodynamic properties of the mixed-spin antiferromagnet Y2BaNiO5 in the spin-1 one-dimensional anisotropic Heisenberg model. We find the correlation function, low-lying excitation, ground-state energy, specific heat and static susceptibility of Y2BaNiO5 for different values of exchange anisotropic parameter γ, and the results are in good agreement with experimental and numerical results.
Numerical simulation of chemical processes in one-dimensional atmospheric plasmas
Authors: Ouyang Jian-Ming  , Shao Fu-Qiu  , Wang Long  , Fang Tong-Zhen  , Liu Jian-Quan  ,   (1)国防科学技术大学理学院，长沙  410073; (2)中国科学院物理研究所，北京  100080
Published: December 2020

We numerically simulated the chemical process and one-dimensional diffusion process in atmospheric plasmas. We deduced the three-component (electrons, positive ions and negative ions) ambipolar diffusion formulas, observed the spatial separation of various components in the diffusion process, and showed the influence of diffusion and chemical processes on the temporal evolutions of the electron number density.
Gap breathers in the one-dimensional Klein-Gordon diatomic chain
Authors: Li Mi-Shan  , Tian Qiang  ,   (1)北京交通大学理学院，北京  100044; (2)北京师范大学物理系，北京  100875
Published: December 2020

The gap breathers (GBs) in a one-dimensional Klein-Gordon diatomic chain are studied under rotating-wave approximation (RWA). The analytical investigation of heavy-particle centered symmetric mode (HS mode) has been implemented under the boundary condition of standing waves. We examine the effects of the coupling constant, nonlinear constant and the mass ratio on the GBs. The GB profiles are sensitive to the coupling constant, nonlinear constant and the mass ratio. As the coupling constant increases, the GB profiles become broader. But, with the nonlinearity and the mass ratio increasing, the GB profiles appear more localized.
Investigation of snapback stress induced gate oxide defect for NMOSFET’s in 90 nm technology
Authors: Zhu Zhi-Wei  , Hao Yue  , Ma Xiao-Hua  , Cao Yan-Rong  , Liu Hong-Xia  ,   西安电子科技大学微电子学院，宽禁带半导体材料与器件教育部重点实验室，西安  710071
Published: December 2020

The experiment result shows that the holes generated by avalanche can be injected into gate oxide of a NMOSFET biased into snapback, and then both hole trapping and interface state generation can be found. These trapped holes may recombine with electrons tunneling into gate oxide due to the ultrathin gate oxide, and then many neutral electron traps would be generated and the gate oxide current would be increased. The threshold voltage would increase and the sub-threshold current would decrease when the injected electrons are trapped by the electron traps. The degradation of drain leakage current can be divided into two phases. Sub-threshold current is predominant in the first phase, while in the second phase gate current is predominant. After pre-HE stress, the generated interface states can reduce the number of holes being injected into gate oxide generated by avalanche process during snapback stress, which causes the MOSFET snapback degradation to decrease in on-state and off-state modes.
Modulation of electron transport though the quantum wire by many side-coupled quantum chains
Authors: Meng Hai-Wei  , Jiang Dong-Tao  , Dai Zhen-Hong  ,   (1)吉林大学物理学院纳米材料的物性与应用系,长春  130000; (2)烟台大学物理系介观物理研究中心,烟台  264005; (3)烟台大学物理系介观物理研究中心,烟台  264005；中国高等科学技术中心，北京  100080
Published: December 2020

Transport through the quantum wire with many side-coupled quantum chains is investigated by using a recursive Green's function technique. We obtained the modulation rules of the parameters N and NU, which are the number of side-coupled quantum chain and the quantum-dot number of side-coupled quantum chain, respectively. The results show that the recursive Green's function method not only can conveniently tune the model and the number of the quantum chain, but also can be applied to study the varied nanofabrication of quantum devices.
Mathematical model of DC characteristic of SiGe charge injection transistors
Authors: Shu Bin  , Zhang He-Ming  , Hu Hui-Yong  , Xuan Rong-Xi  , Dai Xian-Ying  ,   西安电子科技大学微电子学院，宽禁带半导体材料与器件教育部重点实验室，西安  710071
Published: December 2020

To visualize the relationship between the collector current and source-drain voltage in the SiGe/Si chare injection transistor (CHINT), the mathematical model of this device is set up by using the tunnel model of two-dimensional hole gas(2DHG)in SiGe/Si quantum well. Then the model is simulated by MATLAB, the result shows that the drain current shows strong negative differential resistance when VDS is about 1.5V, which is in accordance with the results of the other papers.
High temperature Raman spectra and micro-structure of Bi4Ge3O12 crystal and its melt
Authors: Zhang Xia  , Wan Song-Ming  , Zhang Qing-Li  , Yin Shao-Tang  , You Jing-Lin  , Chen Hui  , Wang Ai-Hua  ,   (1)上海市钢铁冶金新技术开发应用重点实验室，上海大学，上海  200072; (2)中国科学院安徽光学精密机械研究所，合肥  230031
Published: December 2020

The High temperature Raman spectra of BGO crystal and melt were studied. The structures of BGO crystal and melt were analyzed. The rule of structure change of BGO crystal with increasing temperature was analyzed. The results show that the peaks of spectra move to the low wavelength and broaden in different degrees. The intensities of spectra peaks decrease, too. And there exit ［GeO4］ and ［BiO6］ bond structure in the melt of BGO crystal, while the bond between ［GeO4］ and　［BiO6］ bond structures disappear, so those two structures are unattached in the melt.
High-efficiency and high-stability phosphorescent OLED based on new Ir complex
Authors: Wang Jun  , Wei Xiao-Qiang  , Rao Hai-Bo  , Cheng Jian-Bo  , Jiang Ya-Dong  ,   电子科技大学光电信息学院，电子薄膜与集成器件国家重点实验室，成都  610054
Published: December 2020

Multi-layer phosphorescent OLED with (tpbi)2Ir(acac) was fabricated which has the structure: ITO/CuPc (40 nm)/α-NPD (45 nm)/CBP: (tpbi)2Ir(acac) (3%, 30 nm)/BCP (20 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (100 nm). Absorption spectra, phosphorescence lifetime of Ir complex, and I-V-L characteristic of the device was tested. The current of the device under low applied voltage conforms to the Richaardon-Schotty emission, and shows linear relationship under high voltage. Gauss peak fit shows the OLED spectra to be composed of α-NPD peak(450 nm), (tpbi)2Ir(acac) main peak(518 nm) and shoulder peak(543 nm). Maximum power efficiency of PHOLED is 12.1 lm/W (at 6V) with luminance 136 cd/m2, and the maximum luminance is 13500 cd/m2 with power efficiency 0.584 lm/W.
Effect of high-intensity ultrasound on restraining solute segregation in Al-Si alloy casting process
Authors: Gao Xue-Peng  , Li Xin-Tao  , Qie Xi-Wang  , Wu Ya-Ping  , Li Xi-Meng  , Li Ting-Ju  ,   (1)大连理工大学三束材料改性国家重点实验室及材料科学与工程学院，大连  116024; (2)大连理工大学三束材料改性国家重点实验室及材料科学与工程学院，大连  116024；大连理工大学原材料特种制备重点实验室，大连  116024; (3)大连理工大学原材料特种制备重点实验室，大连  116024
Published: December 2020

The influence of high-intensity ultrasound on the microstructure and the distribution of solute elements Si in α (Al) of Φ10mm Al-1% Si alloy bonding wire produced by horizontal continuous casting have been investigated. Experimental results show that under high-intensity ultrasonication the microstructure is refined, the solid solubility and the uniformity of the distribution of Si in α (Al) are improved and the solute segregation is suppressed. The effect of high-intensity ultrasonic vibration on restraining solute segregation in Al-1% Si alloy ingot in horizontal continuous casting is explained from such factors as the diffusion of solute, solidification interval, solidifying front shape, temperature field, flow pattern and microstructure.
Designing the microstructure of the coated radar absorbent
Authors: Zhang Shuan-Qin  , Shi Yun-Long  , Huang Chang-Geng  , Lian Chang-Chun  ,   (1)山西大同大学固体物理研究所，大同  037009; (2)总装工程兵技术装备研究所; (3)总装工程兵技术装备研究所；山西大同大学固体物理研究所，大同  037009
Published: December 2020

The model for the effective electromagnetic coefficients is established. The influence of the volume ratio of the outer layer and the inner on the absorption and the characteristic impedance is discussed. The microstructure of the coated absorbent is designed. Sol-gel method is used to prepare the coated radar absorbent. It is shown by the theoretical and experimental results that the absorbing ability of the coated magnetic absorbent has be improved greatly, and the absorbing band below -8 dB is about 9 GHz.
A new Young tableau method of obtaining equivalent-electron Young basis
Authors: Hu Kun-Ming  , Wang Jian-Bo  ,   商丘师范学院物理与信息工程系，商丘 476000
Published: December 2020

In this paper, the projection function of regular Young tableau of equivalent-electrons is proved to be a Slauer function, and the operation rules of Young's permutation operators operating on the Slater function are given. The Young operators can be distinguished as elimination operator and effective permutation operator by the normalization of Young basis, then the constructive rules of permutation operators of the orthogonal normalization of Young basis is given. By this method, the number of Young's permutation operators is reduced and the new Young tableau method of obtaining equivalent-electron Young basis is represented.
An investigation on local area control of virus spreading in complex networks
Authors: Xu Dan  , Li Xiang  , Wang Xiao-Fan  ,   上海交通大学自动化系，上海 200240
Published: December 2020

The local area control of virus spreading is studied in the light of the path length in complex networks, and the efficiency of local area control for complex networks with different topologies is analyzed. The research suggests that local area control method is effective in the WS small world networks, the BA scare-free networks, and the ER random networks; but the optimal radii d=3 of the local control area for zero infection applies only to the WS small world networks. In the Kleinberg small world networks, when the distance bias of long-range links increases, the epidemic threshold increases, and the effect of local area control strengthens.
φ60，1000 μm Si-PIN Detectors for pulsed γ flux measurement
Authors: Ouyang Xiao-Ping  , Li Zhen-Fu  , Ho Yu-Kun  , Song Xian-Cai  ,   (1)复旦大学现代物理研究所,上海 200433; (2)清华大学工程物理系,北京 100084;西北核技术研究所,西安 710024; (3)西北核技术研究所,西安 710024; (4)中国工程物理研究院电子学研究所,绵阳 621900
Published: December 2020

Using high-resistivity (10000—20000 Ω·cm) n-type Si wafers,we have developed φ60 PIN semiconductor detector with depletion thickness ～1000 microns for low-intensity pulsed γ-ray flux measurement.For determination of thickness of the depletion depths, a recoil proton chamber with 20° scattering angle has been constructed.The detector's performance have been measured and analyzed,which indicates that the developed detector satisfactorily meets the expected specifications.Compared with the existing detectors with depletion depths of 200—300 microns,the detector has much greater γ detecting sensitivity and suited for measuring pulsed γ-ray flux in low-intensity mixed γ/n fields.
The preliminary result of laser- focused Cr atomic deposition for fabricating nanostructure
Authors: Ma Yan  , Zhang Bao-Wu  , Zheng Cun-Lan  , Ma Shan-Shan  , Li Fo-Sheng  , Wang Zhan-Shan  , Li Tong-Bao  ,   同济大学物理系,上海 200092
Published: December 2020

The technology of laser-focused atomic deposition can be used to develop the nanostrucrure transfer standard of length. When the frequency of laser standing wave is higher than the resonant frequency of atoms, the atoms will be focused on the wave node of the standing wave. The collimated Cr atoms are focused by a standing-wave laser field as they are deposited on a silicon substrate. Atomic force microscopy measurements shows a spacing of 215nm.
Antireflection coating for two-dimensional air hole-type photonic crystal negative refraction slab lens
Authors: Zhang Bo  , Wang Zhi  ,   (1)北京交通大学电子信息工程学院国家电工电子教学基地,北京 100044; (2)北京交通大学理学院光信息科学与技术研究所,北京 100044
Published: December 2020

We propose and optimize the antireflection coating composed of a row of tapered dielectric waveguides for two-dimensional air hole-type photonic crystal negative refraction slab lens. The image quality of the lens with the antireflection coating is improved. The simulation result using finite difference time domain method shows, at the working frequency leading to the effective index neff=-1, the reflection rate of the surface of photonic crystal with anti-reflection coating is reduced to below 1% in the range of incident angle less than 23 degrees.
Axial property of the inner surface of a metal tube processed by GEPSII
Authors: Zhang Gu-Ling  , Wang Jiu-Li  , Chen Guang-Liang  , Feng Wen-Ran  , Gu Wei-Chao  , Niu Er-Wu  , Fan Song-Hua  , Liu Chi-Zi  , Yang Si-Ze  ,   (1)北京凝聚态物理国家重点实验室，中国科学院物理研究所，北京 100080; (2)中央民族大学物理与电子工程学院，北京 100081;北京凝聚态物理国家重点实验室，中国科学院物理研究所，北京 100080
Published: December 2020

As a novel inner surface processing method, grid enhanced plasma source ion implantation (GEPSII) method can realize uniform inner surface ion implantation of a metal tube and metal binary compound can be produced. In the experiment, three 0.45% carbon steel (45-steel) work pieces were axially put on the inner surface of the tube, and golden titanium nitride (TiN) films were produced on the work pieces by GPSII. Structure analysis shows that the TiN films have the preferred crystal faces (111) and (200), and the depth of the films is about 20 nm with partial embedding in the substrate. Analysis on the electrochemistry corrosion, hardness and friction of the work pieces indicates that the surface property of the 45-steel has been greatly improved by the protective TiN film, and very good axial uniformity has been obtained.
Generation and suppression of deep level defects in InP
Authors: Zhao You-Wen  , Dong Zhi-Yuan  ,   中国科学院半导体研究所，北京 100083
Published: December 2020

Deep level defects in as-grown and annealed n-type and semi-insulating InP have been studied. After annealing in phosphorus ambient, a large quantity of deep level defects were generated in both n-type and semi-insulating InP materials. In contrast, few deep level defects exist in InP after annealing in iron phosphide ambient. The generation of deep level defects has direct relation with in-diffusion of iron and phosphorus in the annealing process. The in-diffused phosphorus and iron atoms occupy indium sites in the lattice, resulting in the formation of P anti-site defects and iron deep acceptors, respectively. The results indicate that iron atoms fully occupy indium sites and suppress the formation of indium vacancy and P anti-site, etc., whereas indium vacancies and P anti-site defects are formed after annealing in phosphorus ambient. The nature of the deep level defects in InP has been studied based on the results.
Theoritical analysis of quasi-isentropic compression via flier-plate with grade wave impadence
Authors: Huang Hai-Jun  , Shen Qiang  , Luo Guo-Qiang  , Zhang Lian-Meng  ,   (1)武汉理工大学材料复合新技术国家重点实验室，武汉 430070; (2)武汉理工大学理学院，武汉 430070;武汉理工大学材料复合新技术国家重点实验室，武汉 430070
Published: December 2020

The process of shock waves propagation in the target material is analyzed theoretically when hitted by a flier-plate with graded wave impedance. Under the impact, the compression curve of target consists of small Hugoniot curves originating from different original states, which are located between the Hugoniot and the isentropic curves. Thus any state between Hugoniot and isentropic curves can be obtained by controlling the number of flier-plate's layers. It provides a theoretical basis for experimental study of off-Hugoniot equation of state. The validity and reliability of the theoretical analysis are supported by the consistency of experimentally measured and calculated interface velocity values.
A method of acquiring a dark hollow beam of nanometer level
Authors: Yan Chang-Chun  , Xue Guo-Gang  , Liu Cheng  , Chen Hao  , Cui Yi-Ping  ,   (1)东南大学电子工程系，南京  210096; (2)徐州师范大学物理系，徐州  221116; (3)徐州师范大学物理系，徐州  221116;东南大学电子工程系，南京  210096
Published: December 2020

By using the finite difference time-domain (FDTD) method, the distribution of the modulus of the electric field intensity is obtained in the near field of an optical fiber head.We found that different dimensions of the cylindrical core in a hollow optical fiber had an influence on the electric field intensity. It is concluded that the size of the cylindrical core must be increased to make the hollow beam to cover a larger area. At the same time, after discussing the two situations that the size of the hollow optical fiber either rather large or rather small, we obtained a dark spot in the near field of the fiber that was almost of the same size as the hollow region (10 nanometer level). However, the background light in the dark hollow beam was brighter, and so the hollow region was designed to be a metal (such as silver). We found that the background light in the dark spot became evidently weaker and a cleaner dark hollow beam was acquired in the near field. When the hollow region was made smaller, the dark spot in the near field would become smaller, even reaching the nanometer level, which offered a method of obtaining a dark hollow beam of nanometer level.
Proposal for single attosecond pulse production with a 43 fs super intense laser pulse
Authors: Cao Wei  , Lan Peng-Fei  , Lu Pei-Xiang  ,   激光技术国家重点实验室，武汉光电国家实验室，华中科技大学，武汉 430070
Published: December 2020

High harmonics generation (HHG) from Ne atom driven by a multi-cycle 43 fs laser pulse is investigated. The numerical simulation demonstrates that when the intensity of the driving laser is over-saturated, the atom will be ionized rapidly during a few optical cycles, this will lead to a continuous multi-plateau structure in the cutoff region of the high harmonics spectrum from the neutral atom. It is also shown that the signal of high-order harmonics from the ion becomes remarkable when the driving laser is super intense. The superposition of an appropriate sub-plateau can give single attosecond soft X-ray pulse, and the effect of HHG from ion has been eliminated through the band selection.
Theoretical study on electric-pulse-induced resistance change in perovskite Pr1－xCaxMnO3 films
Authors: Li Qian  , Wang Zhi-Guo  , Liu Su  , Xing Zhong-Wen  , Liu Mei  ,   (1)东南大学物理系，南京 210096; (2)东南大学物理系，南京 210096;淮阴师范学院物理系，淮阴 223001; (3)休斯敦大学物理系,休斯敦,TX77204 美国
Published: December 2020

We developed a effective tunneling model to study the electric-pulse-induced resistive switching (EPIR) effect in PCMO films, and find that the tunneling probability of the charge transport at interfaces plays an important role in the EPIR effect. We also study the nonvolatile characteristics and the hysteretic current-voltage curve in the PCMO films, the calculated results consistent with the recent experimental data. This electric-pulse- induced resistive switching effect at room temperate has excellent potential of application.
The effect of terminal group on the electronic transport property of alkanethiol self-assembled monolayer
Authors: Hu Hai-Long  , Zhang Kun  , Wang Zhen-Xing  , Kong Tao  , Hu Ying  , Wang Xiao-Ping  ,   (1)中国科学技术大学合肥微尺度物质科学国家实验室，合肥 230026; (2)中国科学技术大学合肥微尺度物质科学国家实验室，合肥 230026；中国科学技术大学物理系，合肥 230026; (3)中国科学技术大学物理系，合肥 230026
Published: December 2020

The electronic transport properties of the alkanethiol self-assembled monolayer (SAM) with various terminal groups on Au (111) surfaces have been investigated by the conducting atomic force microscopy (CAFM). The results show that the terminal group has obvious effect on the conductance of the SAMs. Combining the X-ray photoelectron spectrum (XPS) analysis and CAFM, we have further studied the relationship between the conductance of SAM and the C1s binding energy of the terminal group of the molecule. It is found that the higher the binding energy, the lower the conductance of the SAM. We attribute this behavior to that the high binding energy would induce strong electronic localization in the terminal group of alkanethiol molecule, which results in raising the effective barrier of the electron injecting into the molecular chains and reducing the transport ability of the electrons in the molecule. In addition, we also find that different group terminated SAMs have different surface potentials, which can shift the zero point of I-V curve of SAMs.
Characteristics of the Si-doped ferromagnetic shape memory alloy Co50Ni21Ga29Six
Authors: Liu Guo-Dong  , Wang Xin-Qiang  , Dai Xue-Fang  , Liu Zhu-Hong  , Yu Shu-Yun  , Chen Jing-Lan  , Wu Guang-Heng  ,   (1)中国科学院物理研究所磁学国家重点实验室，北京 100080; (2)重庆大学数理学院，重庆 400044; (3)重庆大学数理学院，重庆 400044；中国科学院物理研究所磁学国家重点实验室，北京 100080
Published: December 2020

In order to improve the properties of Co—Ni—Ga alloys, experiments of adding Si to Co50Ni21Ga29 alloys were carried out to examine the effect of Si in quaternary Co50Ni21Ga29Six (x=1—2) alloys on their structure, martensitic transformation behavior and magnetic properties. The Co50Ni21Ga29Six (x=1,2) single crystals were successfully grown. All the samples with low Si doping show a sharp martensitic transformation with increasing temperature. The single crystal samples show a completely recoverable two-way shape memory with a strain of 2.5% upon the thermoelastic martensitic transformation. A large magnetic-field-induced strain of 110 ppm was measured at room temperature. A small quantity of Si doping can down-shift the martensitic transformation temperature, reduce the thermal hysteresis, decrease the magnetization but increase the Curie temperature. Especially, the Si doping can increase the magnetic anisotropy of Co—Ni—Ga-alloys, which is available to obtain large magnetic-field-induced strain in a low magnetic field. An electronic resistance “jump" of 4.5% upon the thermoelastic martensitic transformation was also reported.
Phase diagrams and magnetization behaviors of transverse random crystal field Ising model
Authors: Xu Ling  , Yan Shi-Lei  ,   (1)苏州大学物理系，苏州 215006; (2)苏州大学物理系，苏州 215006；苏州大学薄膜材料江苏省重点实验室，苏州 215006
Published: December 2020

Within the framework of the effective field theory (EFT) and cutting approximation, the spin-1 transverse random crystal field Ising model is investigated for a square lattice. We discuss in detail the influence of transverse random crystal field concentration and crystal field ratio on the phase diagram and magnetization behavior. We give phase diagrams in T-Dx space and magnetization curves in m-T space. Under crystal field dilution condition, there exists the peak value of critical temperature in the direction of negative crystal field and reentrant phenomena in the direction of positive critical field. While choosing crystal field ratio α=+0.5 and α=-0.5, the range of magnetic ordered phase shrinks. In particular, we found, with decreasing of concentration, the peak value of critical temperature undergoes a crossover from negative to positive direction of transverse crystal field when the ratio α=-0.5. The magnetization behaviors have apparent difference for a given negative crystal field value when the crystal field ratio is different. We give a meaningful comparison with the results of Ising model with longitudinal dilution crystal field.
XRD analysis on lattice structure of La1-xTexMnO3
Authors: Tan Guo-Tai  , Chen Zheng-Hao  ,   (1)北京凝聚态物理国家实验室，中国科学院物理研究所，北京 100080; (2)射线束技术与材料改性教育部重点实验室,北京师范大学低能核物理所，北京市辐射中心,北京 100875
Published: December 2020

Based on X-ray powder diffraction data, the lattice structure and symmetry of La1-xTexMnO3 (0.04≤x≤0.2) have been analyzed by Rietveld refining method. the results show that all samples structure have a rhombohedral symmetry with space group R3C, and the lattice of MnO6 octahedron has a stretching distortion due to the difference in cation size. Besides, the degrec of structure distortion is closely related to Te content and can be depicted with the following three factors: the Mn—O—Mn bond angle θMn—O—Mn, the average A-site radius 〈rA〉 and the A-site sizemismatch σ2. According to the changing trend of these factors, several conjecture on physical properties are discussed, including the Curie temperature, spin-glass and phase separation etc.
Effect of Ti(Cr) underlayer on the magnetic properties and microstructure of CoCrTa film for perpendicular magnetic recording media
Authors: Zhen Cong-Mian  , Ma Li  , Zhang Jin-Juan  , Liu Ying  , Nie Xiang-Fu  ,   河北师范大学物理科学与信息工程学院，石家庄 050016
Published: December 2020

C/CoCrTa/X (X=Cr, Ti) films were fabricated with DC facing target magnetron sputtering apparatus. Their magnetic properties and microstructure were characterized by vibrating sample magnetometer (VSM), X-ray diffraction (XRD), and scan probe microscope (SPM), respectively. The experimental results indicate that the Ti underlayer can induce the c-axis orientation of Co grain in the direction perpendicular to the film surface. For samples with Ti underlayer, the grain size and the surface roughness are relatively finer, and magnetic domains can be observed obviously. These results show that the sample with Ti underlayer is more suitable for the perpendicular magnetic recording media.
Spectroscopic properties of self-exited Raman scattering of the Nd3+:SrMoO4 crystal
Authors: Han Lin  , Song Feng  , Wan Cong-Shang  , Zou Chang-Guang  , Yan Li-Hua  , Zhang Kang  , Tian Jian-Guo  ,   天津市南开大学物理科学学院光子学中心，天津 300071
Published: December 2020

The spectral performance of a self-Raman-active material (Nd:SrMoO4 crystal) was investigated. Its stimulated Raman scattering (SRS), absorption spectra, luminescence lifetime, and infrared emission under 808 nm LD excitation were measured at room temperature. All vibration modes in the SRS spectra were identified. The most intense vibration is Ag (898 cm-1) mode, which is assigned to fully symmetric extension vibrations of the (MoO2-4) group. Optical parameters were calculated from absorption spectra with Judd-Ofelt (J-O) theory. The integrated emission cross-section and spontaneous emission probability corresponding to 1068 nm emission are 0.57×10-18 cm2 and 141.06 s-1， respectively. The lifetime of the 1068 nm emission was measured to be 0.2 ms. Considering the infrared luminescence excited by 808 nm LD, the possibility of obtaining 1180 nm first-Stokes component relevant to the 1068 nm emission is demonstrated. These conclusions can be our guidance to develop high-efficiency new-wavelength self-excited Raman lasers.
Study on the structure and stability of the Al2O3Hx(x=1—3) molecules by density function theory
Authors: Chen Xiao-Hong  , Gao Tao  , Zhu Zheng-He  , Luo Shun-Zhong  ,   (1)四川大学原子与分子物理研究所，成都  610065; (2)西华大学物理实验中心，成都  610039;四川大学原子与分子物理研究所，成都  610065; (3)中国工程物理研究院，绵阳  621900
Published: December 2020

The geometric configuration，electronic structures and vibrational frequency of the Al2O3Hx(x=1—3) molecules were calculated using B3LYP method at 6-311++g(d,p) level systematically. The calculations give the total energies, zero point energies, mol heat capacities under constant volume, standard entropies, atomization energies, vertical ionization energies, vertical electron affinity energies of their possible ground state structures. The geometric configurations of possible ground state structures of Al2O3H and Al2O3H2 molecules are planar. The geometric configurations of two possible ground state structures of Al2O3H3 molecule are solid geometric configurations which come from the solid geometry of Al2O3 with D3h symmetry adding three hydrogen atoms to oxygen atoms and aluminum atoms. The configurations of these three molecule clusters with lowest energy are: Al2O3H (2A′)Cs, Al2O3H2(1A′)Cs and Al2O3H3(2A)C1.
New explicit exact solutions of one type of generalized Boussinesq equations and the Boussinesq-Burgers equation
Authors: Gao Liang  , Xu Wei  , Tang Ya-Ning  , Shen Jian-Wei  ,   (1)西北工业大学应用数学系，西安 710072; (2)西北工业大学应用数学系，西安 710072;许昌学院数学系，许昌 461000
Published: December 2020

In this paper, explicit exact solutions of one type of generalized Boussinesq equations (B(m，n) equations) and the Boussinesq-Burgers equation (B-B equation) are investigated using a generalized algebraic method. A variety of explicit exact solutions, such as solitary wave, triangular periodic, rational, Jacobi and Weierstrass elliptic function periodic solutions are obtained.
Discussion on building the net of quantum teleportation using three-particle entangled states
Authors: Zhou Xiao-Qing  , Wu Yun-Wen  ,   吉首大学物理科学与信息工程学院，吉首 416000
Published: December 2020

We may make three-particle entanglement using the source of three-particle W states. Put this particle entanglement down as quantum channel, and transfer information of Bell states measurement and von Neumann measurement using classical channel, the quantum teleportation net may then be realized. Based on this idea, we investigate the physical principle for building the quantum teleportation net using three-particle W states, find out the unitary transformation matrix for quantum teleportation of three-particle W states, and design a quantum teleportation net. We propose a scheme for quantum communications net and its protocol. If all stations work as schemed, quantum communications between any two stations may be realized.
Study on the two-lane feedback controled car-following model
Authors: Chen Xuan  , Gao Zi-You  , Zhao Xiao-Mei  , Jia Bin  ,   北京交通大学交通运输学院，北京 100044
Published: December 2020

In this paper we extend the single-lane feedback control model to the two-lane case, named as the two-lane optimal velocity feedback control (OVFC) model. Compared with the two-lane optimal velocity model, simulation results indicate that no serious traffic jams occur in the OVFC system when the feedback signal is introduced, and the oscillation of velocity becomes weaker or vanishes. This means that the two-lane OVFC model can suppress the traffic jams effectively.
Experimental investigation of interaction of two Laguerre-Gaussian modes carrying opposite topological charges
Authors: Zhang Xiao-Bo  , Zhang Wei  , Shu Fang-Jie  , Li Yong-Ping  ,   (1)中国科学技术大学物理系，合肥  230026; (2)中国科学技术大学物理系，合肥  230026;安徽省光电子技术重点实验室，合肥  230026
Published: December 2020

The interaction of two Laguerre-Gaussian(LG) modes carrying opposite topological charges in a linear medium is investigated experimentally. The changes of diffractive pattern are observed when these two LG modes propagate, and a dark arc happens by the central dark particles of the two LG modes joining together in case the interaction of two LG modes carrying opposite topological charges propagate in a linear medium. This experimental phenomenon proves that the screw phase dislocations evolve into a new type of dislocation—edge phase dislocation with the optical field propagating.
Linear entropy evolution in a dissipative system of two atoms and cavity field
Authors: Yang Xiong  , Tong Zhao-Yang  , Xiang Shao-Hua  ,   (1)湖南师范大学物理与信息科学学院，长沙 410081; (2)怀化学院物理与信息科学系，怀化 418008
Published: December 2020

Some investigations have been made on the evolution of the linear entropies of atom-field system, in which two identical two-level atoms simultaneously interact with a single-mode dissipative cavity field under large detuning. The effects of the initial atom states and the dissipative factors of the cavity on all linear entropies are also discussed. The results show that the influence of the cavity decay constant on different kinds of Bell states is completely different, and the state |Ψ〉12 is a robust entangled state against the decoherence while the state |Φ〉12 is a fragile entangled state.
Interaction of an atom with a squeezed field of time-varying frequency
Authors: Zhang Wan-Juan  , Wang Zhi-Guo  , Xie Shuang-Yuan  , Yang Ya-Ping  ,   同济大学物理系，上海 200092
Published: December 2020

The interactions between a two-level atom and a squeezed field of time-varying frequency have been investigated. The properties of the atomic population inversion for two typical cases——the frequency of the field varying with time in the forms of sine function and rectangular pulses——have been considered. For the frequency changing with time in sinusoidal form, the collapse-revival phenomenon of the atomic population inversion is deformed not only by the frequency-modulation but also by the squeeze coefficient and the squeeze phase of the field. The sudden jumping of the field with rectangular pulsed frequency-modulation can lead to new collapses and revivals in the evolution of the atomic population inversion. The rectangular pulsed frequency-modulation can also lead to small-amplitude fast oscillations of the atomic population inversion during the pulse. There is no relation between the latter phenomena and the squeeze coefficient of the field.
Stable differential-phase-shift quantum key distribution based on weak coherent pulses
Authors: Zhao Feng  , Lu Yi-Qun  , Wang Fa-Qiang  , Chen Xia  , Li Ming-Ming  , Guo Bang-Hong  , Liao Chang-Jun  , Liu Song-Hao  ,   (1)华南师范大学信息光电子科技学院，广州 510006; (2)华南师范大学信息光电子科技学院，广州 510006;陕西理工学院电信工程系，汉中 723003
Published: December 2020

Differential phase shift quantum key distribution(DPSQKD) experiment based on weak coherent pulses have been performed in the laboratory. We encoded the bit information between the consecutive pulses. The bit information was decoded at Bob's side by Michelson-Faraday interferometer and single photon detector. This kind of quantum key distribution system can provide stable key distribution process, high efficiency of key creation, and high security key. So it is easily implemented in optical fibers using readily available optical telecommunication tools. We experimented DPSQKD over 76 km on fiber, the error rate of the sifted key is 5.3%. The quantum key distribution process is controlled by micro-computer based on ARM (advanced RISC(reduced instruction set computing) machines) processor.
The effect of Ⅲ-family element doping on electronic structures and electrical characteristics of SnO2
Authors: Du Juan  , Ji Zhen-Guo  ,   杭州电子科技大学电子信息学院,杭州 310018;浙江大学硅材料国家重点实验室, 杭州 310027
Published: December 2020

The electronic structures of SnO2 doped by Al, Ga and In were examined using density functional theory. Density of states (DOSs) calculation showed that the Fermi levels of all Ⅲ-family doped SnO2 systems shift to lower energy and therefore a partially occupied valence band was formed near the valence maxima, which indicates that substitional Ⅲ-group atoms act as acceptors in SnO2. Partial DOSs indicates that compared with substitional Al, substitional Ga or substitional In contribute much more because of the d states, Ga3d or In4d, which suggests that Ga and In is better than Al for p-type doping of SnO2. Ionization energy calculation further indicates that,of the substitional In, Ga and Al, substitional In has the smallest ionization energy of 0.06 eV, which means that substitional In gives the shallowest acceptor level in SnO2, and thus the highest hole concentration at the same doping concentrations.
Theoretical study of thermodynamic properties of metal Be
Authors: Song Hai-Feng  , Liu Hai-Feng  ,   北京应用物理与计算数学研究所，北京 100088
Published: December 2020

We present first-principles calculations combined with mean-field potential model to study the thermodynamic properties of hexagonal-close-packed (hcp) Be for pressures up to 150GPa and temperatures up to 1500K, including the properties of Be under ambient conditions, the isothermal equation of state up to high pressure, the temperature dependence of equilibrium volumes and bulk modulus under ambient pressure, and Hugoniot curve in the P-V plane. The equationof state at zero temperature is computed based on density-functional theory within the generalized-gradient approximation. The vibrational contributions are calculated by the mean-field potential model. Due to high Debye temperature of Be, we consider the zero-point energy correction to the free energy. The calculated properties are in good agreement with available static and shock-wave experimental measurements.
The influence of electric field introduced polymer molecular orientation on the formation cross-section of singlet and triplet excitons in PLED
Authors: Liu Jun  , Hou Yan-Bing  , Sun Xin  , Shi Quan-Min  , Li Yan  , Jin Hui  , Lu Jing  ,   发光与光信息技术教育部重点实验室,北京交通大学光电子技术研究所,北京 100044
Published: December 2020

Ir (PPY)3 and DCJTB doped PVK films were fabricated in the presence of electric field which induced the orientation of polymer molecules, and their photoluminescence and electroluminescence were measured. The influence of electric field-induced orientation on the formation cross-sections of singlet and triplet excitons is investigated. The results showed that the electric field-induced orientation of polymer does not cause significant change in PL spectrum. However, the orientation of polymer results in obvious change in EL spectrum. For the devices based on polarized PVK, the EL from triplet states is reduced, which shows that polarization of PVK leads to the increase in the formation cross-section of singlet exciton and the decrease in the formation of triplet exciton.
Numerical investigation on single-mode single-polarization photonic crystal fiber using resonant absorption effect
Authors: Liu Xiao-Yi  , Zhang Fang-Di  , Zhang Min  , Ye Pei-Da  ,   北京邮电大学光通信与光波技术教育部重点实验室，北京  100876
Published: December 2020

In this paper, a novel single-mode single-polarization photonic crystal fiber using resonant absorption effect has been put forward for the first time. A full vector finite element method is employed to simulate the fiber properties, including mode field distribution, confinement loss，bandwidth and extinction ratio. Numerical results show that very large bandwidth of single-mode single-polarization operation can be attained and extremely high extinction ratio can be achieved with low loss penalty. The influence of structural parameters on the fiber performance has been investigated. The research results will be instructive for the design and fabrication of new high performance single-mode single-polarization fibers.
Calculating physical failure probability of HTR-10’s residual heat removal system by response surface method
Authors: Xie Guo-Feng  , He Xu-Hong  , Tong Jie-Juan  , Zheng Yan-Hua  ,   (1)清华大学核能技术设计研究院，北京 100084; (2)湘潭大学材料与光电物理学院,湘潭 411105
Published: December 2020

Probability safety assessment has been widely used in nuclear plant safety research, but the reliability research of passive system is at a beginning level. The failure of passive system consists of components failure and physical process failure. Calculating the failure probability of physical process is a very difficult task due to the uncertainties of the factors which affect the physical process, and the method for the calculation is quite different from that of active system. The paper introduces response surface method to calculate the failure probability, and applies the method to get the approximate failure probability of residual heat removal system in HTR-10, the 10MW high temperature gas reactor designed by the Institute of Nuclear and New Energy Technology at Tsinghua University.