bluuebunny/crossref_metadata_2025 huggingface dataset:
The localized properties of electronic states in one-dimensional disordered binary solid
Authors: Liu Xiao-Liang  , Xu Hui  , Ma Song-Shan  , Song Zhao-Quan  ,   中南大学物理科学与技术学院，长沙  410083
Published: December 2020

Based on the tight-binding model of the single electron, the 1D model of disordered binary alloy is established, where two different diagonal energies εA and εB are assigned at random to each lattice site and only the short-range hopping integrals between the lattice sites are considered. Using the negative eigenvalue theory and the infinite order perturbation theory, we calculate numerically the eigenvalues and the eigenvectors of the electronic states. The results show that the electronic wave-functions only exist in some narrow region of the system and the localization properties are expected. Using the transfer matrix method, we calculate the localization lengths and discuss how they change with the eigen-energies and the degree of disorder and discuss some characteristics of the localization length with different hopping integral ranges.
Substrate and process dependence of gate oxide reliability of 0.18μm dual gate CMOS process
Authors: Zhao Yi  , Wan  Xing-Gong  ,   (1)东京大学材料系,东京113-8656,日本; (2)上海集成电路研发中心,上海  201203
Published: December 2020

V-ramp method was used to evaluate gate oxide reliability of 0.18μm dual gate CMOS process. Charge of breakdown (Qbd) and voltage of breakdown (Vbd) of gate oxide with n-type substrate and p-type substrate were extracted. It was found that for low voltage (thin oxide) gate oxide device the Qbd of gate oxide of n-type substrate and p-type substrate are almost the same, but for high voltage (thick oxide) gate oxide device the Qbd of n-type substrate and p-type substrate have a big difference. At the same time, Qbd of gate oxide with p-substrate is bigger than that of gate oxide with n-substrate. The difference of Qbd of thin gate oxide and thick gate oxide can be attributed to lithographic damage to the interface of poly-silicon gate and thick gate oxide. There is a big difference between the Weibull slopes of charge of breakdown of thin oxide and thick oxide. For the voltage of breakdown, Similar difference between n-substrate and p-substrate gate oxide was also observed. However, there is no big difference between the Weibull slopes of voltage of breakdown of thin oxide and thick oxide.
Effect of Mn doping on properties of NiFeGa ferromagnetic shape memory alloys
Authors: Yu Shu-Yun  , Liu He-Yan  , Qu Jing-Ping  , Li Yang-Xian  , Liu Zhu-Hong  , Chen Jing-Lan  , Dai Xue-Fang  , Wu Guang-Heng  ,   (1)河北工业大学材料学院，天津  300130; (2)河北工业大学材料学院，天津  300130;中国科学院物理研究所磁学国家重点实验室，北京  100080; (3)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

Light doping of Mn in Ni54Fe19Ga27 plays a significant role in enhancing the magnetic exchange interaction and the rigidity of crystal lattice, it also increases the Curie temperature and stabilizes B2 phase of the material. The oriented internal stress in the single crystals improves the reorientation of the variants due to the existence of Mn. This greatly increases the shape memory deformation and the magnetic field-controlled strain. The internal stress also has an obvious effect on the superelastic behaviors.
A method for reducing eddy current induced by gradient coils
Authors: Shen Jie  , Ning Rui-Peng  , Liu Ying  , Li Geng-Ying  ,   华东师范大学光谱学与波谱学教育部重点实验室，物理系，上海  200062
Published: December 2020

In this paper, a method for reducing the eddy current induced in the magnet with an eddy-current-resisting board by reducing the radius of the gradient coil is proposed. First, the method is analyzed using a theoretical model. Then a gradient coil with reduced radius is designed by using a target field method, and the gradient linear region is verified by using the Biot and Savart's law. Finally, an experiment is performed to testify the result proposed in principle.
Improved dielectric and ferroelectric characteristics of highly (111)-oriented Pb(Zr0.52Ti0.48)O3 films produced by sol-gel method
Authors: Zheng Fen-Gang  , Chen Jian-Ping  , Li Xin-Wan  ,   (1)上海交通大学区域光纤通信网与新型光通信系统国家重点实验室，上海  200030; (2)苏州大学物理科学与技术学院，苏州  215006;上海交通大学区域光纤通信网与新型光通信系统国家重点实验室，上海  200030
Published: December 2020

Highly (111)-oriented Pb(Zr0.52Ti0.48)O3 (PZT) films with a variety of PZT buffer layer thickness were prepared by spin coating on Pt/Ti/SiO2/Si substrates with Sol-Gel process. The thickness of PZT buffer layer was found to play a significant role on grain size and orientation of Pb(Zr0.52Ti0.48)O3 films. With the increasing of PZT buffer layer thickness, both crystallization and orientation were improved obviously. High dielectric constant (1278, 1kHz, for 28nm buffer), low dielectric loss (0.023, 1kHz, for 28nm buffer), symmetric C-V characteristics and P-E curves were obtained. Hysteresis measurements show that the remnant polarization and coercive field of the films reach 43μC·cm-2 and 78kV·cm-1, respectively.
Role of exchange interaction in the magnetic and magneto-optic properties of CeF3 crystal
Authors: Zhang Guo-Ying  , Xia Tian  , Cheng Yong  , Xue Liu-Ping  , Zhang Xue-Long  ,   (1)华北科技学院物理系，河北廊坊  065201; (2)上海理工大学医疗器械学院，上海  200093; (3)中国矿业大学理学院物理系，徐州  221008
Published: December 2020

The exchange interaction between electrons exists in the paramagnetic media CeF3. The relation of the effective exchange field Hin to the temperature is shown to be Hin=(-0.68-0.002T)×10-6M. By means of this relation and the quantum theory, the inverses of the magnetic susceptibility and Verdet constant of CeF3 crystal as a function of temperature are calculated. The calculated V-1-T and χ-1m-T curves are in good agreement with the measured results. The results are further discussed in Terms of the concepts and rules of photo-magnetic effect.
Analysis of phase mismatch in magneto-optic Bragg diffraction
Authors: Wu Bao-Jian  ,   电子科技大学通信与信息工程学院，成都  610054
Published: December 2020

The magneto-optic (MO) coupled-mode equations for magnetostatic waves (MSWs) and guided optical waves (GOWs) under phase-mismatch conditions were deduced and applied to the noncollinear interaction with magnetostatic backward volume waves (MSBVWs) in obliquely magnetized yttrium-iron-garnet (YIG) film using single-element microstrip line transducer. The diffraction efficiency (DE) of the incident TE0-mode light was calculated. For the case of magnetization along the MSBVW propagation direction, the calculated results are in good agreement with the experimental data. In contrast, by using an appropriately tilted bias magnetic field the DE can be increased by 6dB and is insensitive to the phase mismatch induced by the change of magnetization direction. Thus, the optimization of the direction of the bais magnetic field is an effective method for improving the diffraction performance and increasing the MO bandwidth of the Bragg cells.
Effects of GeO2 on the thermal stability and optical properties of Er3+-doped germanate-tellurite glasses
Authors: Zhao Chun  , Zhang Qin-Yuan  , Yang Zhong-Min  , Jiang Zhong-Hong  ,   (1)华南理工大学光通信材料研究所，特种功能材料制备新技术教育部重点实验室，广州  510641; (2)华南理工大学光通信材料研究所，特种功能材料制备新技术教育部重点实验室，广州  510641；华南理工大学物理科学与技术学院，广州  510641
Published: December 2020

Germanate-tellurite glasses with the molar compositions of x GeO2-(70-x) TeO2-5K2O-5Na2O-10Nb2O5-10ZnO-0.2Er2O3 (x=0,10, 25, 50, 70) have been investigated for developing 1.5μm fiber and planar amplifiers. Effects of GeO2 on the thermal stability and optical properties of Er3+-doped germanate-tellurite glasses have been discussed. It is noted that the thermal stability of the glasses are improved and the maximum phonon energy are increased by increasing GeO2. Adding GeO2 increases the Judd-Ofelt parameters Ω2, Ω6 but decreases the stimulated emission cross sections σe. According to the McCumber theory, the maximum peak of σe is 9.92×10-21cm2 at 1.53μm in germanate-tellurite glasses. The maximum FWHM of Er3+4I13/2→4I15/2 emission spectrum is 52 nm. In addition, the intensity of upconversion luminescence of the Er3+-doped germanate-tellurite glasses decreases rapidly with increasing GeO2 content.
Optical properties of Pb(Mg1/3Nb2/3)O3-PbTiO3 thin films prepared by chemical solution deposition
Authors: Liu Ai-Yun  , Meng Xiang-Jian  , Xue Jian-Qiang  , Sun Jing-Lan  , Ma Jian-Hua  , Wang Lin  , Chu Jun-Hao  ,   中国科学院上海技术物理研究所红外物理国家重点实验室，上海  200083
Published: December 2020

92%Pb(Mg1/3Nb2/3)O3-8%PbTiO3 (PMNT) thin films have been prepared on Pt/Ti/SiO2/Si substrate with a LaNiO3 (LNO) buffer layer and on sapphire substrate by chemical solution deposition, respectively. X-ray diffraction analysis shows that the PMNT thin films on Pt/Ti/SiO2/Si substrate are almost pure perovskite phase with (110)-preferential orientation. The optical constants (n, k) of the PMNT thin films in the wavelength range of 2.5—12.6μm were obtained by infrared spectroscopic ellipsometry measurement. By fitting the optical transmission spectra of the PMNT thin films on sapphire substrate in the wavelength range of 200—1100nm, the optical constant (n and k) and absorption coefficient (α) were obtained. And that the bandgap energy of the PMNT thin films on sapphire substrate was found to be about 4.03eV.
Dynamics of the Lorenz system under quasiperiodic driving
Authors: He Wen-Ping  , Feng Guo-Lin  , Gao Xin-Quan  , Chou Ji-Fan  ,   (1)国家气候中心，中国气象局气候研究开放实验室，北京  100081; (2)兰州大学大气科学学院，兰州  730000；扬州大学物理学院，扬州  225002; (3)兰州大学大气科学学院，兰州  730000；扬州大学物理学院，扬州  225002;中国科学院大气物理研究所东亚区域气候-环境重点实验室，北京  100029; (4)中国科学院大气物理研究所东亚区域气候-环境重点实验室，北京  100029;国家气候中心，中国气象局气候研究开放实验室，北京  100081
Published: December 2020

We have investigated the dynamics of the Lorenz system under quasiperiodic driving. When the forcing amplitude is increased to certain critical value，the dynamics changes fundamentally. Therefore a new mechanism for the creation of the strange nonchaotic attractor is advanced in this paper. When the forcing amplitude is increased, the strange attractor is replaced by a strange nonchaotic attractor, eventually the phase space is suppressed into an invariant quasiperiodic torus. Numerical results show that the critical amplitude of the force is roughly proportional to the Rayleigh parameter, but slightly influenced by its frequency.
Fuzzy edge detection technique using multi-information fusion algorithm
Authors: Zong Xiao-Ping  , Xu Yan  , Dong Jiang-Tao  ,   河北大学电子信息工程学院，保定  071002
Published: December 2020

An effective fuzzy edge detection algorithm is proposed in this paper. This novel algorithm is different from other fuzzy edge detection algorithms based purely on image enhancement technology. Several kinds of information are used as the characteristics of edge detection, and fuzzy logic is used to fuse the information together. So, the edge detecting process is more effective and gives much better edge information. It is proved that this algorithm is applicable to detect the edge of highly-noisy images.
The fractal structure of silicon content in molten iron in blast furnace
Authors: Luo Shi-Hua  , Liu Xiang-Guan  ,   (1)浙江大学数学系,系统优化技术研究所, 杭州  310027; (2)浙江大学数学系,系统优化技术研究所, 杭州  310027；宁波大学数学系, 宁波  315211
Published: December 2020

With ［Si］ time series of No. 1 BF at Laiwu Iron and Steel Group Co. and No.6 BF at Linfen Iron and Steel Group Co. as sample space, and based on rescaled range analysis and method of box dimension, the Hurst exponents of ［Si］ time series of these two BFs and the box dimensions are figured out to be ranging from 0.257 and 0.224 and 1.712 and 1.724, respectively. The complex degree of ［Si］ time series is described, and it is also proved that ［Si］ time series is a long-term negative association fractal time series. With the correlative parameter fixed, the simulated trend was pictured by the theory of iterated function system.
Self-organized criticality in one-dimensional sandpile model with avalanche probability included
Authors: Zhou Hai-Ping  , Cai Shao-Hong  , Wang Chun-Xiang  ,   (1)贵州财经学院，贵阳  550004;贵州省光电子技术及应用重点实验室，贵阳  550025; (2)贵州大学物理系，贵阳  550025;贵州省光电子技术及应用重点实验室，贵阳  550025
Published: December 2020

Proposed an one-dimensional sandpile model which include avalanche probability, and performed computer simulation by cellular automata method. The results show that there are two critical points p1 and p2 when avalanche probability p transits from 0 to 1. The self-organized criticality(SOC) behavior can be found in the model when p12. There is a sharp transition between the trivial behaviour and the SOC behaviour in the model. When there is SOC, the SOC behaviour is universal, the two critical exponents are 1.50±0.02 and 1.58±0.15. With the model, the SOC phenomenon appearing in the experiment of one-demensional rice-pile is well explained.
Evolution of ionization front and its effects on laser pulse propagation in gaseous targets
Authors: Chen Min  , Sheng Zheng-Ming  , Zhang Jie  ,   中国科学院物理研究所光物理重点实验室，北京  100080
Published: December 2020

When an intense laser pulse propagates in a gaseous target, an ionization front is produced at the leading edge of the laser pulse, which moves at the speed of light. By use of a one-dimensional particle-in-cell code with the field ionization included, we simulate the interaction between the laser pulse and its ionization front. It is found that, because of the discontinunities in atomic ionization potentials for different ionization orders, a flat-top region of the electron density appears inside the ionization front at the beginning. The ionization induces blue shif in the laser frequency, which modifies the laser pulse into a step-like profile. This new pulse profile in turn shortens the flat-top region in the ionization front. Generally the ionization front evolves into several parts, corresponding to different ionization orders, with different plasma density gradients. The effects of different gas elements and initial gas densities on the produced ionization fronts have been investigated. The conditions ith regard to the laser intensity and gas species to produce steep density gradients in ionization fronts have been studied for applications in frequency up-conversion by use of counter-propagating light pulses. Finally, the spectrum evolution of the ionizing pulse is investigated and the resulting fine spectrum structure located between the fundamental and the second harmonic is analyzed.
Research on photoionization of Ar·NO cluster using synchrotron radiation
Authors: Wang Si-Sheng  , Kong Rui-Hong  , Tian Zhen-Yu  , Shan Xiao-Bin  , Zhang Yun-Wu  , Sheng Liu-Si  , Wang Zhen-Ya  , Hao Li-Qing  , Zhou Shi-Kang  ,   (1)中国科学技术大学国家同步辐射实验室，合肥  230029; (2)中国科学院安徽光学精密机械研究所激光光谱学开放研究实验室，合肥  230031
Published: December 2020

A supersonic beam of NO molecules mixed with Ar atoms was ionized by VUV synchrotron radiation from Hefei Light Source(HLS) at National Synchrotron Radiation Laboratory (NSRL). Photoionization efficiency spectroscopy (PIES) measurement was made for NO, Ar and heterogeneous clusters Ar·NO. In PIES spectum of Ar·NO, a strong resonance peak at the position of atomic rare gas resonance lines (11.5—12.0 eV) was observed, and it is shown that the excitation energy of the rare gas atom is transferred to the attached NO molecule within a heterogeneous cluster, leading to ionization of the molecule NO.
A novel cold plasma jet generated by capillary atmospheric dielectric barrier discharge
Authors: Sun Jiao  , Zhang Jia-Liang  , Wang De-Zhen  , Ma Teng-Cai  ,   大连理工大学三束材料改性国家重点实验室，大连  116023
Published: December 2020

An easy-operated and effective scheme is presented to generate a novel kind of atmospheric cold plasma millimeter jet. The jet operates with many kinds of working gas at atmosphere pressure, such as Ar, He and N2, in a capillary quartz dielectric barrier discharge (DBD) system powered by a pulsed power source with a frequency of 33kHz and variable voltage of 1—12kV. Via an CCD imager, the initial discharge filaments in the DBD gap are found to be transformed into diffusion discharge or glow-like discharge by the flowing gas through the DBD gap, and a plasma jet formed in the outlet of the capillary is viewed simultaneously. The critical velocity of the gas flow for the plasma jet formation is determined to be 3—8m/s for different working gases by a well-designed enthalpy probe. The jet range for a special gas can be changed by the increase of the gas flow velocity while the jet range for different gases varies a lot and the helium jet takes the longest range of about 44mm when the helium flows at a elocity of about 20m/s. Beyond the velocity limit of 20m/s for laminar helium flow, the jet of helium plasma becomes torrent and unstable and its range turns shorter. Based on the OES analysis of He plasma jets, it is determined that the excitation temperature of He jets lay in the range 2000K—3000K, which is much lower than the excitation temperature of a normal arc plasma torch and hints that the jet is cold especially when compared to the arc plasma torch.
B-site Fe doping effect on the structure and electronic transport properties of quasi-one-dimensional spin ladder compound Sr14(Cu1－yFey)24O41
Authors: Hu Ni  , Xie Hui  , Wang Li-Li  , Lin Ying  , Xiong Rui  , Yu Zu-Xing  , Tang Wu-Feng  , Shi Jing  ,   (1)武汉大学物理科学与技术学院教育部声光材料与器件重点实验室，武汉  430072; (2)武汉大学物理科学与技术学院教育部声光材料与器件重点实验室，武汉  430072；中国科学院国际材料物理中心，沈阳  110016
Published: December 2020

Two groups of Sr14(Cu1-yFey)24O41 compounds with Fe3+ doping and 2/3Fe3++1/3Fe2+ admixture doping respectively were prepared by conventional solid-state reaction. X-ray diffraction analysis shows that the samples have single phase with y≤0.03 of Fe3+ doping and y≤0.02 of 2/3Fe3++1/3Fe2+ admixture doping. The lattice parameters a and b decrease gradually when the doping content increases for each group. The measurements of electronic transport properties show that the electrical resistivity decreases monotonically with the increase in y of Fe3+ doping, which indicates that free hole carriers in the ladder increase. A crossover temperature Tρ was observed in the Arrhenius plot of the resistivity versus temperature. The decrease of resistivity of the Fe3+ doped samples is interpreted in term of the dissociation of spin dimers and hole pairs located in the ladder induced by the substitution of Fe3+ for Cu2+ .Two kinds of possible conduction mechanisms above and below Tρ are presented respectively. The fitting of experimental data proves that the conduction mechanism above Tρ is due to thermal activated single-holes′ contribution, while below Tρ one-dimensional hopping conduction is dominant.
Generation of multi-source inductively coupled plasma and its diagnostics
Authors: Xin Yu  , Di Xiao-Lian  , Yu Yi-Qing  , Ning Zhao-Yuan  ,   苏州大学物理科学与技术学院，江苏省薄膜材料重点实验室，苏州  215006
Published: December 2020

In recent years, in order to cut down the production cost, substrates with large area are used in semiconductor industry, especially in the field of thin film transistor display. Obviously, the key point for the substrate fabrication needs a uniform plasma sources with large area. Among them, inductively couple plasma is one of the good candidates. In our experiments, based on a small chamber of inductively coupled plasma with a single multi-turn coil, we investigated the relationship between coil configuration and power coupling efficiency, and applied these experimental results to the generation of large-area inductively coupled plasma with parallel-connected multi-sources. By using Langmuir probe measurement, plasma parameters of this kind of large area ICP were characterized. It was shown that the large-area ICP source with parallel-connected multi-sources can produce a plasma density lager than 1010cm-3 under a rather low pressure (<10Pa). The uniformity of plasma density and the photoresist etching can be controlled to a level better than 80% by adjusting the process parameters.
A comparison of ionizing radiation damage in CMOS devices from 60Co Gamma rays, electrons and protons
Authors: He Bao-Ping  , Chen Wei  , Wang Gui-Zhen  ,   西北核技术研究所，西安  710613
Published: December 2020

The stopping power and accumulation energy for protons in SiO2 are calculated by using Monte Carlo software TRIM95. As a result, the ionizing stopping power and the nucleus stopping power are compared for protons in SiO2, and the relation between absorption dose of material surface and factual absorption dose of sensitive area is discussed. CC4007RH and CC4011 devices were irradiated with Co-60 gamma rays, 1MeV electrons and 1—9MeV protons to compare the ionizing radiation damage of the gamma rays with the charged particles. The result show that the radiation damages from Co-60 gamma rays, 1MeV electrons and 1—7MeV protons were equivalent for 0V gate bias conditions. Under 5V gate bias, the radiation damage for Co-60 gamma rays was most serious. The distinction in damage between 1MeV electrons and Co-60 gamma rays was not large. The damage from protons below 9MeV was always less than that from Co-60. The lower the proton energy, the less the damage.
Size effect on serrated yielding in Al-Cu polycrystals
Authors: Lu Jun-Yong  , Jiang Zhen-Yu  , Zhang Qing-Chuan  , Jiang Hui-Feng  , Liu Hao-Wen  ,   中国科学技术大学，中科院材料力学行为和设计重点实验室，合肥  230027
Published: December 2020

In this paper, through a systematic statistical analysis of the characteristics of the serrated yielding, including the stress drop amplitude and the drop duration, etc., the difference between the results of thinner samples (1mm and 2mm) and those of thicker samples (3mm), has been reported. The size effect in Portevin-Le Chrtelier (PLC) effect also manifests itself in the difference of PLC types of jerky flow of 1mm or 2mm thick samples and those of 3mm thick samples under the same experimental conditions. Moreover, the geometrical characteristics of attractor of the former series in phase space are described by using methods of nonlinear time series analysis, and chaotic behavior is proved to exist in these series through the application of principal component analysis. The distribution of stress drops of the latter is found to follow a power-law distribution, which is referred to as the signature of self-organized criticality phenomenon.
First-principles study on the electrical structures and optical properties of β-Si3N4
Authors: Pan Hong-Zhe  , Xu Ming  , Zhu Wen-Jun  , Zhou Hai-Ping  ,   (1)四川师范大学物理与电子工程学院固体物理研究所，成都  610068; (2)四川师范大学物理与电子工程学院固体物理研究所，成都  610068；中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室，绵阳  621900; (3)四川师范大学物理与电子工程学院固体物理研究所，成都  610068；重庆邮电学院光电工程学院,重庆  400065
Published: December 2020

Electrical structures and optical properties of β-Si3N4 have been calculated by means of plane wave pseudo-potential method (PWP) with GGA. The results such as lattice constants and band structures are in good agreement with experimental data. Furthermore, the pressure-dependent coefficient and band gap of β-Si3N4 have also been calculated, which will be helpful in the application of Si3N4 under high pressure.
Theoretical analysis about the influence of channel layer thickness on the 2D electron gas and its distribution in InP-based high-electron-mobility transistors
Authors: Li Dong-Lin  , Zeng Yi-Ping  ,   中国科学院半导体研究所材料中心, 北京  100083
Published: December 2020

The principle of high-electron-mobility transistor (HEMT) and the property of two-dimensional electron gas (2DEG) have been analyzed theoretically. The concentration and distribution of 2DEG in various channel layers are calculated by numerical method. Variation of 2DEG concentration in different subband of the quantum well is discussed in detail. Calculated results show that sheet electron concentration of 2DEG in the channel is affected slightly by the thickness of the channel. But the proportion of electrons inhabited in different subbands can be affected by the thickness of the channel. When the size of channel lies between 20—25 nm, the number of electrons occupying the second subband reaches the maximum. This result can be used in parameter design of materials and devices.
Ground state properties of spin-Peierls ladder model with interchain superexchange interactions
Authors: Liu Hai-Lian  , Wang Zhi-Guo  , Yang Cheng-Quan  , Shi Yun-Long  ,   (1)同济大学波耳固体物理研究所,上海  200092; (2)雁北师范学院固体物理研究所,大同  037009; (3)雁北师范学院固体物理研究所,大同  037009;同济大学波耳固体物理研究所,上海  200092
Published: December 2020

The ground-state properties of spin-Peierls ladder model with interchain Heisenberg interaction and interchain Dzyaloshinskii-Moriya(DM)interaction are studied by Lanczos numerical method. We mainly concentrate on the influence of interchain Heisenberg interaction and interchain DM interaction on system dimerization. The results show that these two interchain interations always act against the dimerization of the system, and they can make system ground state dimerization diminishing, which means that increasing the system dimensions may reduce system dimerization, even destroy the dimerization phase.
Dielectric properties of Na0.25K0.25Bi0.5TiO3 lead-free ceramics
Authors: Zhao Su-Chuan  , Li Guo-Rong  , Zhang Li-Na  , Wang Tian-Bao  , Ding Ai-Li  ,   (1)中国科学院上海硅酸盐研究所,上海  200050; (2)中国科学院上海硅酸盐研究所,上海  200050;上海大学物理系,上海  200444
Published: December 2020

Na0.25K0.25Bi0.5TiO3(NKBT50)lead-free ceramics were prepared by solid-state reaction. The dielectric property of the ceramics was investigated in the lemperature range from room temperature to 400℃. Our results show that there exists a dielectric anomaly in the vicinity of 70℃ for the unpoled ceramics sintered in air, which will disappear after the ceramic were poled or sintered in oxygen. It is believed that the dielectric anomaly is caused by defect dipoles related to oxygen vacancies. Thermal stimulated depolarization current shows that the materials are depolarized at 225℃ and the dielectric anomaly corresponding to this phase transition is also affected by oxygen vacancies.
F-P photonic crystal filter in terahertz region
Authors: Zhou Mei  , Chen Xiao-Shuang  , Wang Shao-Wei  , Zhang Jian-Biao  , Lu Wei  ,   (1)中国科学院上海技术物理研究所红外物理国家重点实验室，上海  200083; (2)中国农业大学理学院应用物理系，北京  100083
Published: December 2020

A series of one-dimensional disordered photonic crystals were designed for use as filters. We prepared the filters experimentally and measured the transmission characteristic of the filters by using infrared spectrometer. The experimental results are in agreement with the calculation results.
Preparation and characterization of Au/SiO2 nano-composite multilayer films
Authors: Zhang Yun  , Zhang Bo-Ping  , Jiao Li-Shi  , Zhang Hai-Long  , Li Xiang-Yang  ,   (1)北京科技大学材料科学与工程学院，北京  100083; (2)北京科技大学材料科学与工程学院，北京  100083;大连理工大学环境与生命学院，大连  116024; (3)钢铁研究总院功能材料研究所，北京  100081
Published: December 2020

Au/SiO2 nano-composite multilayer thin films were prepared by magnetron plasma sputtering. The effect of microstructure on the absorption spectra of films of the same thickness but under different deposition conditions, and films deposited under the same conditions but having different thicknesses was investigated. The results show that the optical absorption peaks appeared at 560 nm for the Au/SiO2 nano-composite multilayer films, the intensity of the absorption peak increased with increasing Au content and thickness of films. No nano-multilayer structure and absorption peak was observed when Au particle connected together due to high Au content. The optical absorption spectra of Au/SiO2 multilayer thin films well agree with the theoretical optical absorption spectra calculated from modified Maxwell-Garnett effective medium theory.
Analysis of magnetoelectric properties of ferroelectric and ferromagnetic columnar composites
Authors: Zhou Jian-Ping  , Shi Zhan  , Liu Gang  , He Hong-Cai  , Nan Ce-Wen  ,   (1)清华大学材料科学与工程系，新型陶瓷与精细工艺国家重点实验室，北京  100084; (2)西安交通大学材料学院 金属材料强度国家重点实验室，西安  710049
Published: December 2020

The magnetoelectric effect can be observed in the composites of magnetostrictive and piezoelectric phases by the the mechanical transfer from one to the other. The large magnetoelectric effect exists in the multiferroic composites with Pb(Zr,Ti)O3 rod arrays embedded in a ferromagnetic medium of (Tb,Dy)Fe2/epoxy. The large magnetoelectric effect and its origin in this structure was discussed on the basis finite element method. The numberical results were close to that of the experiment. The distributions of strain, stress and electric polarization and their relation were analyzed. The authors gave a way to improve the magentoelectric effect based on the distribution of the electric polarization.
Formation and composition optimization of Cu-based bulk metallic glasses in Cu-Zr-Ti ternary system
Authors: Wang Qing  , Qiang Jian-Bing  , Wang Ying-Min  , Xia Jun-Hai  , Lin Zhe  , Zhang Xin-Fang  , Dong Chuang  ,   (1)大连理工大学三束材料改性国家重点实验室及原材料特种制备技术实验室，材料工程系，大连  116024; (2)大连理工大学三束材料改性国家重点实验室及原材料特种制备技术实验室，材料工程系，大连  116024;中国科学院国际材料物理中心，沈阳  110016; (3)香港城市大学物理及材料系，九龙，香港;大连理工大学三束材料改性国家重点实验室及原材料特种制备技术实验室，材料工程系，大连 116024
Published: December 2020

The present paper investigates the formation and composition characteristics of Cu-based bulk metallic glasses (BMGs) in the inter-transition metal system Cu-Zr-Ti by using an “e/a-variant criterion” which is relevant to clusters. Three such composition lines, (Cu9/13Zr4/13)100-xTix, (Cu０.618Zr０.382)１００-xTix and (Cu０.56Zr０.4４)100-xTix, are defined in the Cu-Zr-Ti system. Among them, Cu９Zr4, Cu61.８Zr38.2 and Cu56Zr44 are specific Cu-Zr binary cluster compositions. Alloy compositions are designed along these three composition lines, and alloy rods with diameter of 3mm are prepared by copper mould casting. X-ray and TEM analysis show that BMGs are formed within Ti content range of x=7.5%—15%, x=7.5%—12.5% and x=5%—12% respectively along these three lines. Thermal analysis results further indicate that these BMGs have igher thermodynamic Tg,Tx,Tg/Tl and γ values, and these values of BMGs on every composition line decrease with increasing Ti content. The optimum BMG composition in this system is Cu64Zr28.５Ti7.5 on the (Cu９/13Zr4/13)１00-xTix series, which also has the highest hardness and activation energy of crystallization. The characteristic parameters of this BMG are Tg＝736K, Tx＝769K, Tg/Tl=0.627,γ=0.403, Hν= 6.74GPa and ΔE=3.88 eV, which are all superior to those of the reported BMG Cu6０Zr3０Ti１０.
Metal nano-hole array copied from AAO template
Authors: Zhao Xin-Feng  , Fang Yan  ,   北京市纳米光电子学重点实验室，首都师范大学物理系，北京  100037
Published: December 2020

Well-aligned and highly ordered nano-hole array copper membranes were copied from anodic aluminum oxide (AAO) template by vacuum plating. SEM shows that the nanoholes of copper membranes are hexagonally arranged with high regularity consistent with that of AAO template. The mean diameter of the holes was dependent on the corresponding parameter of AAO template. Compared with AAO membranes, the nano-hole array metal ones have many advantages in better chemical and thermal stability and higher mechanical strength, and are likely to play an important role in nano-copy field.
Massive particles’ Hawking radiation via tunneling
Authors: Zhang Jing-Yi  , Zhao Zheng  ,   (1)北京师范大学物理系，北京  100875; (2)北京师范大学物理系，北京  100875;湛江师范学院物理系，湛江  524048
Published: December 2020

In this paper the tunneling framework is adopted to investigate the Hawking radiation. The emission rate which massive particles tunnel across the event horizon of the Schwarzschild black hole is calculated. It is consistent with an underlying unitary theory and takes the same functional form as that of massless particles.
Lie symmetry and non-Noether conserved quantities of variable mass Birkhoffian system
Authors: Zhang Peng-Yu  , Fang Jian-Hui  ,   中国石油大学(华东)物理科学与技术学院，东营  257061
Published: December 2020

In this paper, the Lie symmetrical non-Noether conserved quantity of variable mass Birkhoffian system under the infinitesimal transformations is studied. First, variable mass Birkhoffian equations are established; second, Lie symmetry determining equations are given. Then the non-Noether conserved quantity is obtained. An example is given to illustrate the application of the result.
Noether-Lie symmetry of non-holonomic mechanical system
Authors: Fang Jian-Hui  , Ding Ning  , Wang Peng  ,   中国石油大学(华东)物理科学与技术学院，东营  257061
Published: December 2020

In this paper, a new symmetry, i.e., Noether-Lie symmetry and its conserved quantities of the non-holonomic mechanical system is studied. The definition and the criterion of the Noether-Lie symmetry for the system are given. A theorem asserting that the Noether-Lie symmetry for the system leads to both the Noether conserved quantity and the general Hojman conserved quantity is presented. An example is given to illustrate the application of the result. The Hojman conserved quantity of the system is a special case of the general Hojman conserved quantity obtained in this paper.
Conditions for Chetaev dynamics to be equivalent to vakonomic dynamics in nonholonomic systems
Authors: Guo Yong-Xin  , Zhao Zhe  , Liu Shi-Xing  , Wang Yong  , Zhu Na  , Han Xiao-Jing  ,   (1)广东医学院基础学院，东莞  523808; (2)辽宁大学物理系，沈阳  110036; (3)沈阳药科大学基础学院，沈阳  110016
Published: December 2020

For general nonholonomically constrained systems, variation identity is used to define three kinds of unfree variations, i.e., nonholonomic variations: the vakonomic, the Hlder and the Suslov by means of vector fields on the extended configuration manifold. The relations among the three kinds variations are discussed and a necessary and sufficient condition for the variations to become free ones is obtained. The nonholonomic variations and the corresponding integral variational principles are utilized to derive the two kinds of dynamical equations: vakonomic equations and Routh's equations or Chaplygins equations. By comparing vakonomic equations with Rouths equations and Chaplygins equations respectively, two necessary and sufficient conditions for the two kinds of equations to have common solutions are obtained, which are not integrable conditions of the constraints.
End structures of single-walled carbon nanotube at different temperatures
Authors: Chen Wei  , Luo Cheng-Lin  ,   南京师范大学物理科学与技术学院，南京  210097
Published: December 2020

We have simulated the end structures of perfect single-walled carbon nanotube at temperatures from 2000 K to 3500 K using tight binding molecular dynamics method. Our calculations suggest that the effect of temperature on the ends of the nanotubes is important. The two ends of a perfect single-walled carbon nanotube closes in turn at 3000 K and 3500 K within 15 ps. As the temperature increases, the two ends of a perfect single-walled carbon nanotube will close more quickly. Both processes of closing of two ends are accompanied by the lowing of the system energy. Moreover, the ends of armchair-type carbon nanotube close easier than those of zigzag carbon nanotube with the same diameter due to the lower strain energy of the former.
The bilateral power-law distribution model of supply chain networks
Authors: Guo Jin-Li  ,   上海理工大学管理学院，上海  200093
Published: December 2020

Basing on the property of supply-chain networks, this paper proposes a randomly growing directional model whose node-arrival process is a renewal process and the number of new edges is a random variable with Bernoulli distribution. We calculate the degree distributions and stationary average degree distributions of the network model by using the renewal process theory and the continuum theory. The paper shows that the supply chain networks have bilateral power-law distributions.
Study on the critical chaotic system with fractional order and circuit experiment
Authors: Wang Fa-Qiang  , Liu Chong-Xin  ,   西安交通大学电气工程学院，西安  710049
Published: December 2020

In this paper, we study the fractional order the critical chaotic system and design an electronic circuit to realization the fractional order. The chaotic dynamic behavior of the fractional order of the critical system is verified by computer simulation and circuit experiment.
Chaotic control of nonlinear systems based on improving the space correlation
Authors: Zhou Xiao-An  , Qian Gong-Bin  , Qiu Shui-Sheng  ,   (1)华南理工大学电子与信息学院，广州  510640; (2)深圳大学信息工程学院，深圳  518060; (3)深圳大学信息工程学院，深圳  518060;华南理工大学电子与信息学院，广州  510640
Published: December 2020

A method of chaotic control based on improving the space correlation is presented. As examples, the Hénon discrete chaotic system and the four-order Chua's circuit is studied numerically. The results show that by improving the space correlation between chaotic signals, the chaotic dynamic systems can be controlled to converge rapidly to its equilibrium point or to the multi-periodic orbits.
Chaotic synchronization with diverse structures based on tracking control
Authors: Li Jian-Fen  , Lin Hui  , Li Nong  ,   (1)空军工程大学工程学院，西安  710038; (2)西北工业大学自动化学院，西安  710072
Published: December 2020

A tracking control method is proposed for chaotic synchronization with diverse structures. When the controlled system satisfies Lipchitz condition, it's proved by means of Lyapunov function that this method can make the controlled chaotic system approach to any desired smooth orbit at an exponenting rate. The model of a designed controller has unique structure for different chaotic systems, and synchronization between any chaotic systems can be achieved. Computer simulations are given to illustrate the effectiveness of the proposed method.
Analysis, circuit implementation and synchronization of a new three-dimensional chaotic system
Authors: Wang Fan-Zhen  , Qi Guo-Yuan  , Chen Zeng-Qiang  , Zhang Yu-Hui  , Yuan Zhu-Zhi  ,   (1)南开大学信息技术科学学院，天津  300071; (2)天津科技大学电子信息与自动化学院，天津  300222
Published: December 2020

Center manifold theory presented an approach that the order of a system can be reduced. This paper investigates the basic characteristic of a new chaotic system by the approach. A flow equation on the center manifold is obtained and the pitchfork bifurcation is analyzed for the new chaotic system. An analog electronic circuit is designed to implement the new system, so the chaotic attractor are verified. We explain the significant distinction of application due to different frequencies used in numerical simulation and circuit implementation. Finally, the synchronization of the new chaotic system is realized by using the single variable coupling feedback, and the circuit of synchronization is presented.
Analysis of bifurcation and chaos in double-well Duffing system via Laguerre polynomial approximation
Authors: Ma Shao-Juan  , Xu Wei  , Li 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;西北第二民族学院信息与计算科学系，银川  750021
Published: December 2020

Laguerre polynomial approximation method is applied to study the period-doubling bifurcation and chaos behavior in double-well Duffing system with a random parameter subjected to harmonic excitation. Firstly the stochastic system is reduced to its equivalent deterministic counterpart, through which the response of the stochastic system can be obtained by numerical methods. Then bifurcation and chaos in the stochastic double-well Duffing system is explored. Numerical simulations show that the nonlinear dynamical behavior is similar to their counterpart in deterministic nonlinear system such as period-doubling bifurcation, but in some local areas they are shown to have their specific features.
Extensive analysis of 4s24p3—4s24p25s transition for RhXⅢ，PdXⅣ and AgXV
Authors: Mu Zhi-Dong  , Wei Qi-Ying  , Chen Di-Ying  ,   中国矿业大学理学院,徐州  221008
Published: December 2020

Extensive analysis of fine-structure energy levels of configurations 4s24p3(4S3/2,2P1/2,3/2, 2D1/2,3/2)and 4s24p25s(4P1/2，3/2，5/2,2P1/2,3/2, 2D3/2,5/2，2S1/2) are made for arsenic isoelectronic sequence of ions from YⅦ to AgⅩⅤ by Hartree-Fock method with relativistic corrections (HFR) using the Cowan code. The Slater parameters of fine-structure level are obtained by least-square-fit for ions mentioned above with the available experimental data, and the unknown parameters are calculated by the generalized-least-square-fit with the extra-(inter)polation method. With these new parameter values, the fine-structure energy levels of 4s24p3, 4s24p25s are computed. All of the 35 electronic-dipole transition wavelengths and its associated oscillator strengths between configurations 4s24p3 and 4s24p25s are calculated for Rh，Pd and AgⅩⅤ. The wavelength uncertainties with the available experimental values for Rh are mostly within 0.003nm. All results of Pd and AgⅩⅤ are predicted values currently anavailable in experiment.
Influence of annealing temperature on the microstructure and photoluminescence of ZnO films
Authors: Sun Cheng-Wei  , Liu Zhi-Wen  , Zhang Qing-Yu  ,   大连理工大学三束材料改性国家重点实验室，大连  116024
Published: December 2020

ZnO thin films with strong c-axis prefered orientation have been successfully deposited on Si(100) substrate at 750℃ by using reactive radio frequency magnetron sputtering. The influence of annealing temperature ranging from 600 to 1000℃on the microstructure and photoluminescence (PL) properties of ZnO films was investigated by Ｘ-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence measurement at room temperature. The XRD and TEM results show that the grain size of ZnO film increases and the residual stress in the film is tensile and remains constant at about 1 GPa with the increase of annealing temperature below 900℃. After annealed at 1000℃, the grain size decreases and the residual stress in the film changes into compressive with the value about -2 GPa. The PL spectra of the ZnO films show two emission bands, namely that originating from ultraviolet (UV) exciton transition and the visible defect photoluminescence. The intensity of UV PL spectrum and the relative intensity of fferent exciton emission are dependent on the grain size and defects in the ZnO film. The red shift of UV PL spectrum results from the change of the relative intensity of different exciton emission with annealing temperature. The visible PL spectrum is sensitive to the change of annealing temperature. The relationship between PL spectra and microstructure and defects in the films is discussed.
Effect of annealing on optical properties of MgxZn1－xO thin films deposited at low temperature
Authors: Zhang Xi-Jian  , Ma Hong-Lei  , Wang Qing-Pu  , Ma Jin  , Zong Fu-Jian  , Xiao Hong-Di  , Ji Feng  ,   山东大学物理与微电子学院，济南  250100
Published: December 2020

MgxZn1-xO films(x=0.16) have been prepared at 80℃ by radio frequency magnetron sputtering. The effect of the annealing temperature on the structure and optical properties of the films are studied using XRD, photoluminescence and the transmittance spectra. The results indicate that the thin films have hexagonal wurtzite single phase structure and a prefered orientation with the c axis perpendicular to the substrate. With increasing annealing temperature the intensities of the XRD (002) peaks increase, the grain size and intensity of the UV photoluminescence peaks also increase, while the FWHM of (002) peaks decreases, which demonstrates that high quality MgxZn1-xO films deposited by RF magnetron sputtering can be obtained by properly controlling the annealing temperature.
Effect of ultrasonic treatment on ZnO film photoluminescence
Authors: Yuan Yan-Hong  , Hou Xun  , Gao Heng  ,   (1)西北大学光子学与光子技术研究所、光电子技术省级重点实验室，西安  710069; (2)西北大学光子学与光子技术研究所、光电子技术省级重点实验室，西安  710069;中国科学院西安光学精密机械研究所，西安  710068
Published: December 2020

The photoluminescence spectrum of ZnO film with high crystal quality has been measured. The peak of near-ultraviolet emission located at 389 nm has been observed. For the ZnO film treated by ultrasonic, not only the ultraviolet peak of ZnO, but also the strong green peak at 508 nm have been observed. It is also found that the intensity of the green peak (508 nm) is stronger than that of the ultraviolet peak. The ultraviolet peak also appears to have red-shift. The intensity of the green peak (508 nm) increases sharply with further heating. The crystal quality of ZnO films is changed by the ultrasonic treatment and oxygen vacancies are produced. The lattice vibration of film is aggravated in the treatment process. When the lattice vibration arrives at certain degree, the lattice oxygen leaves the lattice site to form oxygen vacancy, and the green peak (about 510 nm) is attributed to oxygen vacancies in the crystal. The density of oxygen vacancies depends on the ZnO film temperature. The higher the film temperaure, the greater the density of oxygen vacancy and the stronger the intensity of the green peak.
Metal-insulator transition and spin-glass behavior in Eu2－xPbx Ru2O7 system
Authors: Qiu Mei-Qing  , Fang Ming-Hu  ,   浙江大学物理系，杭州   310027
Published: December 2020

The investigation on the structure, resistivity and susceptibility was carried out for Eu2-xPbxRu2O7 (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0 and 1.8) samples. It is found that the resistivity of the samples, the local magnetic moment of Ru4+ and the freezing temperature TG of spin glass decrease gradually with the increasing substitution concentration value x of Pb for Eu in Eu2-xPbxRu2O7 system. A metal-insulator (M-I) transition occurs near x=0.8. It is suggested that in this system the partial substitution of Pb2+ for Eu3+ results in the increasing of carrier concentration. And the mixing of 6p band of Pb and the t2g band of Ru 4d electrons brings about an enhancement of itinerary for Ru 4d electrons.
Bound states of relativistic particles in the second P?schl-Teller potentials
Authors: Zhang Min-Cang  , Wang Zhen-Bang  ,   陕西师范大学物理学与信息技术学院,西安  710062
Published: December 2020

The s-wave bound states of the Klein-Gordon equation and Dirac equation with the Second Pschl-Teller scalar and vector potentials are obtained, and the solutions are expressed in terms of hypergeometric function.
Criterion for validity of potential and limiting atom number in a potential well for Bose-Einstein condensation gas
Authors: Yu Xue-Cai  , Ye Yu-Tang  , Cheng Lin  ,   电子科技大学光电信息学院，成都  610054
Published: December 2020

Based on Bose-Einstein condensation at minimized momentum state, a criterion for the validity of potential and the limited atom number loaded in a power law attractive potential well for ultra-cold atom gas is deduced. The criterion gives the required potential intensity when the loaded atom number is defined, or the limited atom number when the potential intensity is decided.
A model describing the degree distribution of collaboration networks
Authors: Zhang Pei-Pei  , He Yue  , Zhou Tao  , Su Bei-Bei  , Chang Hui  , Zhou Yue-Ping  , Wang Bing-Hong  , He Da-Ren  ,   (1)江苏大学理学院物理系,镇江  212013; (2)无锡市第一中学,无锡  214031; (3)扬州大学物理科学与技术学院,扬州  225002; (4)中国科学技术大学近代物理系,合肥  230026
Published: December 2020

This paper discusses the degree distribution of a type of social networks and some technological networks with similar topological structures. Firstly, we propose a most simplified model and try to show analytically that the degree distribution and the act degree distribution are well consistent, but the distribution of the number of the nodes inside an act have much smaller influence on the degree distribution. Secondly, we perform numerical simulations in a more general situation of the model, so as to show that the above mentioned conclusion is rather universal. This model leads to a conclusion that these generalized collaboration networks usually have a degree distribution between the power law and the exponential function. In the last part of the article, we introduce very briefly the results of the empirical statistical investigation on some practical collaboration networks to show that the model is valid for generalized collaboration networks.
Analog implementation of wavelet transform based on switched-current filter circuits
Authors: Hu Qin-Chun  , He Yi-Gang  , Guo Di-Xin  , Li Hong-Min  ,   (1)湖南大学电气与信息工程学院，长沙  410082; (2)湖南理工学院计算机与信息工程系，岳阳  414006
Published: December 2020

A general scheme for the analog implementations of wavelet transform using switched_current (SI) filter circuits is presented. SI circuits are well suited for this application since the dilation constant across different scales of the transform can be precisely implemented and controlled by both the transconductance ratios (W/L) and the clock frequency. The circuits are composed of analog filter banks whose impulse responses are the first derivative of Gaussian and its dilations. The transfer functions of the basic wavelet filter can be given by Pad approximation, which can decompose the transfer function into rational form so as to be conveniently implemented by SI circuits. Therefore, it can easily be applied to other filters with a prescribed impulse response. Simulated results indicated a good performance of wavelet transform.