bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of chaotic behavior for press time series of oil pipeline
Authors: Liu Jin-Hai  , Zhang Hua-Guang  , Feng Jian  ,   (1)东北大学信息科学与工程学院，沈阳  110004; (2)东北大学信息科学与工程学院，沈阳  110004；东北大学教育部暨辽宁省流程工业综合自动化重点实验室，沈阳  110004
Published: December 2020

Usually, pressure fluctuation in oil pipeline is assumed to be stochastic or as white noise, which hinders the improvement of fault diagnosis technology based on pressure fluctuation. To find the internal dynamics of pressure fluctuation in oil pipeline, the possibility of existing chaotic behavior is validated using the method of nonlinear analysis. Six experimental data sets are studied on which phase spaces are reconstructed, the fractal dimensions and Lyapunov exponents are computed and the stationary feature and nonlinearity are validated. By the analysis of the results, the rigorous chaotic character of pressure fluctuation in oil pipeline is found, which is a theoretical basis for the correlative investigation based on pressure time series of oil pipeline.
Study of the global behavior of wireless sensor networks based on cellular automata
Authors: Zhang Wen-Zhu  , Yuan Jian  , Yu Zhe  , Xu Zan-Xin  , Shan Xiu-Ming  ,   清华大学电子工程系,北京  100084
Published: December 2020

Study of the association between local and global behaviors is essential for self-organizing communication system design and system control. A cellular automaton-based model is proposed for addressing the topology control problem of wireless sensor networks which well captures the essential features of system behaviors. It is shown that the system behaviors vary with different local rules, and may have oscillating, decreasing or stable patterns. Moreover, this model can also reflect the tradeoff between different system requirements, which maybe inspiring for further study.
Complex network community structure of two-phase flow pattern and its statistical characteristics
Authors: Gao Zhong-Ke  , Jin Ning-De  ,   天津大学电气与自动化工程学院，天津  300072
Published: December 2020

We extract the flow pattern complex network from the measured data. After detecting the community structure of the network through the community detection algorithm which is based on k-means clustering, we find that there are three communities in the network, which correspond to the bubble flow, slug flow and churn flow respectively, and the nodes of the network that are connected tightly between two communities correspond to the transitional flow. In this paper, from a new perspective, we not only achieve good identification of flow patterns in gas/liquid two-phase flow based on complex network theory, but also find the characteristics of flow pattern complex network that are sensitive to the flow parameters, which provide reference to the study of dynamic properties of two-phase flow.
Theoretical study of the electron transport in the molecular contact
Authors: Niu Xiu-Ming  , Qi Yuan-Hua  ,   (1)山东大学物理与微电子学院,济南  250010; (2)山东医学高等专科学校,济南  250002
Published: December 2020

Based on the density functional theory (DFT) and non-equilibrium Green function (NEGF) method, we present calculations of the electron transport properties of a hydrogen molecule contacting two Pt micro-electrodes. The conductance we obtained agrees well with that of the experiment. The conceptual picture of Feynman path is used to explain our result. The local states of the contact are related to the peaks of the transmission spectrum.
Theoretical calculation of the scattering cross section for He-HF(DF,TF) collision system
Authors: Wang Rong-Kai  , Shen Guang-Xian  , Yu Chun-Ri  , Yang Xiang-Dong  ,   (1)安庆师范学院物理与电气工程学院，安庆  246011; (2)贵州师范大学理学院，贵阳  550001; (3)贵州师范大学理学院，贵阳  550001；四川大学原子与分子物理研究所，成都  610065; (4)四川大学原子与分子物理研究所，成都  610065
Published: December 2020

For the first time, the interaction potentials of the He-HF(DF,TF) van der Waals complexes have been obtained by center of mass transformation and then employing Murrell-Sorbie potential function to fit the accurate interaction energy data, which have been computed at symmetry-adapted perturbation theory (SAPT) level. On the basis of the above results, the close coupling calculation of scattering cross sections for collision of He with HF(DF,TF) is performed by employing the fitted interaction potential. This calculation is performed at the incident energies of 50, 59.5, 86, 100 and 120 meV, respectively. The information of the elastic, inelastic and total integral cross sections were obtained, and the change tendency and characteristics of scattering cross section are discussed for He-HF(DF,TF)collision system.
An electrostatic dynamic model for wind-blown sand systems
Authors: Lu Lu-Yi  , Gu Zhao-Lin  , Luo Xi-Lian  , Lei Kang-Bin  ,   (1)日本理化学研究所，和光 351-0198，日本; (2)西安交通大学能源与动力学院，西安  710049; (3)西安交通大学人居环境与建筑工程学院，西安  710049
Published: December 2020

An electrostatic dynamic model for wind-blown sand systems of dust devils or sand-dust storms was developed based on the electrochemistry of water molecular film on the surface of particles, in which water is ionized as H3O+/HO- and their concentration vary with temperature. The mobility of H3O+ from high concentration regime to low concentration regime is greater than that of HO-. The interaction of particles result in the change of particle kinetic energy and the particle surface temperature. The simulation of a three-sized particle system with diameters of 0.1, 0.2, and 0.4mm and particle numbers of 750, 100 and 50, respectively, shows that the small particles are charged negatively while the large particles are charged positively, which reasonably explains the electrostatic mechanism of dust devils and sand-dust storms. It was also found that the electrification is relevant to the humidity of granule system, which explains Guardiola's experiments. Coupled with gas-particle two-phase flow model, this electrostatic dynamic model will improve the accuracy of numerical simulation of the wind-blown sand system.
The influence of the field frequency modulation on quantum entanglement via two-photon process
Authors: Cheng Qiu-Li  , Xie Shuang-Yuan  , Yang Ya-Ping  ,   同济大学物理系，上海  200092
Published: December 2020

The entanglement degree is investigated by means of the entropy theory between a two-level atom and a coherent field with varying frequency via two-photon transition. We restrict our attention to two cases, the field frequency varying with time in the forms of sine and rectangle. When the field frequency varies with time in the form of sine, the entanglement degree will increase sharply and maintain high values. By changing the amplitude α and angular frequency β of the field-frequency variation respectively, we find that the evolution process is more sensitive to the former. In the rectangular modulation case, different results will be produced when the pulses appear at different time. Comparing the pulses appearing at every minimum value with that at every maximum value, the entanglement degree will increase and reach stability more quickly and easily in the lattev case. The sudden change caused by the rectangular modulation is particularly beneficias to the control of the value of the field entropy.
The property of quantum noise in active Raman gain medium
Authors: Lu Cui-Ping  , Yuan Chun-Hua  , Zhang Wei-Ping  ,   华东师范大学精密光谱科学与技术国家重点实验室和物理系，上海  200062
Published: December 2020

We study a three-level atom assemble interacting with a pump field and a quantum probe field, and derive the Langevin quantum noise operators and quantum noise spectrum due to vacuum fluctuations via quantum theory. We calculate the output noise spectrum of active Raman scattering field through the medium when introducing one nonclassical squeezing field.
Efficient diode stack end-pumped continuous-wave Nd∶YVO4 slab lasers
Authors: Zhang Heng-Li  , Yan Ying  , Du Ke-Ming  ,   (1)EdgeWave GmbH,Steinbachstr. 15,52074 Aachen,Germany; (2)北京理工大学信息科学与技术学院，北京  100081
Published: December 2020

Efficient diode stack end-pumped slab lasers with a hybrid cavity were demonstrated. About 60 W of near-diffraction-limited output was obtained with Nd∶YVO4 slab crystals. The lower doped Nd∶YVO4 crystal shows the possibility of further power scaling with near-diffraction-limited output but it also increases the sensitivity of the wavelength to the temperature of the cooling water.
Carrier-envelope phase extraction with wavelet-transform technique of amplified ultrashort optical pulses
Authors: Deng Yu-Qiang  , Cao Shi-Ying  , Yu Jing  , Xu Tao  , Wang Qing-Yue  , Zhang Zhi-Gang  ,   (1)天津大学精密仪器与光电子工程学院，天津  300072; (2)天津大学精密仪器与光电子工程学院，天津  300072；北京大学信息学院，北京  100871; (3)中国计量科学研究院光学与激光计量科学研究所，北京  100013; (4)中国计量科学研究院光学与激光计量科学研究所，北京  100013；天津大学精密仪器与光电子工程学院，天津  300072
Published: December 2020

A novel technique, based on wavelet-transform analysis, was introduced for the carrier-envelope phase extraction in this paper. With wavelet analysis technique, the carrier-envelope phases of amplified ultrashort optical pulses were directly extracted from the spectral interferences. The technique need no Fourier-transform and filter procedure, therefore, the uncertainty introduced from the filter is avoided naturally. Wavelet-transform technique extracted accurate carrier-envelope phase, therefore we hope it can find applications in the measurements and characterizations of few- to mono-cycle femtosecond optical pulses.
A new reconstructing algorithm for removing polarization effect of incident X-ray source and twin images in X-ray fluorescence holography
Authors: Xie Hong-Lan  , Hu Wen  , Luo Hong-Xin  , Du Guo-Hao  , Deng Biao  , Chen Rong-Chang  , Xue Yan-Ling  , Shi Shao-Meng  , Xiao Ti-Qiao  ,   中国科学院上海应用物理研究所，上海  201800
Published: December 2020

This paper discusses the influence of the polarization of incident X-vay on the reconstructed atomic image by numerical simulation and reconstruction, using a crystalstructure composed of 27 Fe atoms arranged in a cubic lattice as the model. Calculated results show that the choice of polarization is crucial for the atom observability. This paper proposes a new reconstructing algorithm which can eliminate the polarization effect of incident X-ray source and twin images inherent to holography at the same time. Numerical simulation and reconstruction results show that the reconstructing algorithm is effective and can be used to eliminate the influence of polarization of incident light source and twin image in experiments.
Field emission properties of well-ordered ZnO nanoneedle arrays
Authors: Xiao Jing  , Bai Xin  , Zhang Geng-Min  ,   北京大学纳米器件物理与化学教育部重点实验室，北京大学电子系，北京  100871
Published: December 2020

Two kinds of vertically aligned, well-ordered zinc oxide nanoneedle arrays were synthesized on silicon substrates without any catalyst by a simple thermal evaporation method. The nanoneedle arrays have uniform distribution and unique orientation and height. The field emission study shows that both of them have not only low turn-on field and threshold field, but also the ability of stable and long time emission. The low turn-on field and threshold field result from the high aspect ratio and thin apex of the nanoneedles. The stable and long time emission are due to the uniform distribution and good contact between the nanoneedles and the substrate. The results show that regular nanoneedle arrays are ideal candidates for flat panel field emission applications.
The deformation mechanism of nanofilm with void under tensile loading: An atomistic simulation study
Authors: Zhang Yang  , Zhang Jian-Hua  , Wen Yu-Hua  , Zhu Zi-Zhong  ,   厦门大学物理系，厦门大学理论物理与天体物理研究所，厦门  361005
Published: December 2020

In this paper, we employ molecular static approach with quantum corrected Sutten-Chen many-body potential to study the mechanical behavior of nickel nanofilm during uniaxial loading, and investigate its microstructure by common neighbor analysis methods. The simulated results show that the existence of void significantly weakens the Young’s modulus and yield stress of nanofilm; with the increased strain, the shape of void changes from circular into elliptical, and the void is eventually entirely closed. The plastic deformation of nanofilm is characterized by {111} glide associated with Shockley partial dislocations, resulting in the formation of stacking faults.
Magnetic field and temperature dependence of the properties of the magnetopolaron in an asymmetric quantum dot
Authors: Eerdunchaolu  , Yu Ruo-Meng  ,   (1)河北科技师范学院凝聚态物理研究所，秦皇岛  066004; (2)华中科技大学物理系，武汉  430074
Published: December 2020

The influence of the magnetic field and temperature on the properties of the strong-coupling magnetopolaron in an asymmetric quantum dot is studied by using the Tokuda’s linear-combination operator and the Lee-Low-Pines variational method. The expressions for the vibration frequency λ, ground state energy E0 and the effective mass m* of the magnetopolaron as a function of the transverse effective confinement strength ω1, the longitudinal effective confinement strength ω2, the electron-phonon coupling strength α, the cyclotron frequency ωc and the temperature parameter γ are derived. Numerical results indicate that λ and m* of the magnetopolaron will increase with increasing ω1,ω2,ωc and α, and will decrease with increasing temperature T. The value of E0 changing with ω1,ω2,ωc,α and γ are srongly related to the propties of the state of the magnetopolaron. The signs of positeve and negative E0 relate not only to the value of ω1,ω2,ωc and α but also to the value of γ. However, only on the condition of higher temperature (γλ,m* and E0 of the magnetopolaron is obvious.
Effects of low-temperature annealing on oxygen precipitate nucleation in heavily arsenic-doped Czochralski silicon
Authors: Xi Guang-Ping  , Ma Xiang-Yang  , Tian Da-Xi  , Zeng Yu-Heng  , Gong Long-Fei  , Yang De-Ren  ,   (1)宁波立立电子股份有限公司，宁波  315800; (2)浙江大学硅材料国家重点实验室，杭州  310027; (3)浙江大学硅材料国家重点实验室，杭州  310027；宁波立立电子股份有限公司，宁波  315800
Published: December 2020

Through the comparative investigation on oxygen precipitation behaviors in the heavily and lightly arsenic-doped n-type Czochralski (CZ) silicon wafers subjected to the two-step annealing successively at low temperature (450—800℃) and high temperature (1000℃), the effects of low-temperature annealing on oxygen precipitate nucleation in heavily arsenic-doped CZ silicon wafer have been elucidated. It was found that for the heavily arsenic-doped CZ silicon the oxygen precipitate nucleation during the 450 and 650℃ annealing was more significant than that during the 800℃ annealing, which was contrary to the case for lightly-doped CZ silicon. Moreover, in comparison with the lightly-doped CZ silicon, the oxygen precipitate nucleation at 450 and 650℃ was enhanced while that at 800℃ was suppressed in the heavily arsenic-doped CZ silicon. It is believed that in the heavily arsenic-doped CZ silicon the As-V-O complexes can be formed during the annealing at 450 and 650℃ so as to enhance the oxygen precipitate nucleation; while, during the 800℃ annealing the As-V-O complexes are not stable enough to act as the precursors of nuclei and, moreover, the heavy arsenic-doping leads to compressive lattice stress, therefore the oxygen precipitate nucleation is noticeably suppressed. Furthermore, it is revealed that the nitrogen-doping facilitates the oxygen precipitate nucleation during the annealing at low temperatures especially at 800℃, which is believed to be due to the heterogeneous nucleation centers induced by nitrogen-doping.
Theoretical optimization for field emission current density from carbon nanotubes array
Authors: Wang Xin-Qing  , Li Liang  , Chu Ning-Jie  , Jin Hong-Xiao  , Ge Hong-Liang  ,   中国计量学院材料科学与工程学院，浙江省磁学重点实验室，杭州  310018
Published: December 2020

With the help of the floating sphere mirror image model and the Fowler-Nordheim equation, the emission current density from carbon nanotube was calculated in this paper. Taking the field enhancement factor and the emission current density into account, the field emission of carbon nanotube array was optimized in theory. The result shoved that the field emission from carbon nanotube array is maximal when the intertube distance is equal to one tenth of the tube height, which is a little smaller than the previous result. When the intertube distance is larger , the field enhancement factor increases, but the emission current density decreases even more rapidly with increasing intertube distance. For carbon nanotube arrays with higher array density, the field enhancement factor decreases greatly with the decreasing intertube distance due to the screening of the electric field.
Effects of circular unit of FSS on the performance of wave absorbing materials
Authors: Lu Jun  , Chen Xin-Yi  , Wang Jian-Bo  ,   长春理工大学理学院，长春  130022
Published: December 2020

Frequency selective surface (FSS) is a two-dimensional array structure, which can be used to improve the performance of radar absorbing materials. We design circular unit of FSS, and give a simulation research on the circular unit of FSS with the spectral domain approach. The result shows that the circular unit of FSS greatly widens the bandwidth of radar absorbing materials, and decreases the reflectivity of resonance frequency; the bandwidth of radar absorbing materials increases with the increasing radius of the unit, and the resonance frequency drifts to low frequency, which provides theoretical support to the application of FSS in wave absorbing materials.
A first principles investigation on NiTi alloy
Authors: Zhu Jian-Xin  , Li Yong-Hua  , Meng Fan-Ling  , Liu Chang-Sheng  , Zheng Wei-Tao  , Wang Yu-Ming  ,   (1)东北大学材料与冶金学院，沈阳  110004; (2)哈尔滨工程大学理学院，哈尔滨  150001; (3)吉林大学材料学院，长春  130012; (4)吉林大学材料学院，长春  130012；东北大学材料与冶金学院，沈阳  110004
Published: December 2020

A first principles plane-wave method is utilized to investigate the bulk properties of the NiTi alloy，such as the lattice parameters, formation energy and cohesive energy and the elastic constant. The results are in good agreement with experimental and other theoretical results.Furthermore,we have studied the geometric and electronic structures of NiTi (100) and(110)surfaces. As to the surface geometry, there are different relaxations in the surface layers. As for the cleaned NiTi(110) surface, outermost surface layer shows a large rippled relaxation in which Ni atoms contract into the bulk by 0.198? and Ti atoms expand to the vacuum by 0.122?. The calculation of the surface electronic structure shows that Ti-terminated surface is more reactive than Ni-terminated surface on (100) surface and the NiTi (110) surface is inert.
The energy and thermal effects of mesoscopic capacitance coupling LC circuit at finite temperature
Authors: Su Jie  , Wang Ji-Suo  , Liang Bao-Long  , Zhang Xiao-Yan  ,   聊城大学物理科学与信息工程学院,聊城  252059
Published: December 2020

For the mesoscopic capacitance coupling LC circuit, the Hamiltonian is given by the canonical quantization. The Hamiltonian operator is diagonalized by a unitary transformation. The ensemble average energy and its fluctuations are derived by ensemble theory. In virtue of the generalized Hellmann-Feynman theorem, the quantum fluctuations of charge and self-conductance magnetic flux for the system at finite temperature are investigated. It is found that, the quantum fluctuations of charge and self-conductance magnetic flux depend on the temperature as well as the parameters of the circuit components.
Study on doping and electrical properties of organic infrared semiconductor phthalocyanine erbium(Ⅲ)
Authors: Tang Li-Bin  , Ji Rong-Bin  , Song Li-Yuan  , Chen Xue-Mei  , Li Yong-Liang  , Rong Bai-Lian  , Song Bing-Wen  ,   昆明物理研究所，昆明  650223
Published: December 2020

The organic infrared semiconductor ErPc2 prepared by solid phase reaction method has been doped with iodine, the resistivity of ErPc2 has been successfully decreased by about three orders of magnitude by doping. The R-T relationships for intrinsic and iodine doped ErPc2 have been studied, it is found that compared with intrinsic ErPc2, the doped ErPc2 has a remarkable decrease in resistivity, the relationship between resistance and temperature for the doped ErPc2 has not been changed intrinsically, both intrinsic and doped ErPc2 exhibit an exponential dependence of R-T. It is also found that the heat activation energy (Ea) has been effectively reduced by doping, which leads to more carriers that may take part in conducting electricity for ErPc2. The decrease in pre-exponential factor (A) may also contribute to reducing resistivity of ErPc2. The exponential relationship between I and V under a strong electrical field strength has also been explained for the intrinsic organic infrared semiconductor ErPc2.
Ferromagnetism in polycrystalline Si0.9654Mn0.0346:B thin films
Authors: Liu Xing-Chong  , Lu Zhi-Hai  , Lu Zhong-Lin  , Zhang Feng-Ming  , Du You-Wei  ,   电子科技大学物理电子学院，成都  610054
Published: December 2020

Polycrystalline Si0.9654Mn0.0346 films codoped with boron have been prepared by rf magnetron sputtering deposition followed by fast thermal processing for crystallization. Magnetic property investigation indicated that the film consists of two ferromagnetic phases. The low Curie temperature ferromagnetic phase (TC～50K) is due to the Mn4Si7 phase in the film as detected by X-ray diffraction (XRD), while the high temperature phase (TC～250K) results from the incorporation of Mn into silicon. The polycrystalline thin films were treated by hydrogen passivation for about 4 minutes using radio-frequency plasma enhanced chemical vapor deposition (PECVD). After hydrogenation, the saturation magnetization increases with the increase of hole concentration in the films. The magnetic properties are closely related to the transport properties of the polycrystalline Si0.9654Mn0.0346 films, which suggests a mechanism of hole-mediated ferromagnetism in Si-based diluted magnetic semiconductors.
Effects of the staggered Dzyaloshinskii-Moriya interaction on entanglement in antiferromagnetic Heisenberg chain
Authors: Cai Zhuo  , Lu Wen-Bin  , Liu Yong-Jun  ,   扬州大学物理科学与技术学院，扬州  225002
Published: December 2020

By using the density-matrix renormalization group method, the spin entanglement in the antiferromagnetic Heisenberg chain with the staggered Dzyaloshinskii-Moriya (DM) interactions is investigated. It is found that the staggered DM interactions remove the field-induced second order quantum phase transition of the system at the magnitude of magnetic field H＝2, and lead to the vanishing of the anomalous behavior of quantum entanglement. Also, the staggered DM interactions eliminate the divergence of entanglement range. It means the disappearance of the factorizing point in the model studied. Due to the presence of the staggered DM interactions, the system will never come to the state of saturated ferromagnetism under finite magnetic fields, thus maintaining the spin entanglement. The staggered DM interactions favor the tuning of the strength and range of spin entanglement.
Micromagnetic simulations of the initial spontaneous magnetic states of nanoscale Fe islands on W(110) substrates
Authors: Yang Xiu-Hui  ,   玉林师范学院物理与信息科学系，玉林  537000
Published: December 2020

The initial spontaneous magnetic domains in nanoscale Fe islands on W(110) substrates are studied numerically with micromagnetic simulations. The critical anisotropies separating different domain states for irregular, elliptic and rectangular shape islands are determined precisely. A full phase diagram of magnetic domain states as a function of anisotropy and thickness is obtained, in which there is a wide transition zone separating two domain states from vortex or diamond domains, and the boundaries on two sides of the transition zone are indefinite. The calculated results indicate that the initial spontaneous magnetic domains are determined mainly by anisotropies and thicknesses, and rim shapes have significant influences on vortex and diamond domain configurations. Further study is needed to determine the exact anisotropies of nanoscale Fe islands.
First order reversal curves of laminated antiferromagnetically coupled media
Authors: Yin Jin-Hua  , C. H. Hee  , Pan Li-Qing  ,   (1)Data Storage Institute,5 Engineering Drive 1,Singapore  117608; (2)北京科技大学物理系，北京  100083
Published: December 2020

First order reversal curves (FORC) were simulated and experimentally measured for the first time for laminated antiferromagnetically coupled (LAC) media. Micromagnetic simulation was effectively utilized in order to understand correctly the various peaks in the FORC contours. The result of the simulation was used to assign the experimentally observed FORC contour peaks to different magnetization reversals. It was observed that the FORC could provide more information than the interactions measured by the conventional delta-M method.
Study of growth units and the growth habit of PbMoO4 crystal using high temperature Raman spectra
Authors: Zhou Wen-Ping  , Wan Song-Ming  , Zhang Xia  , Zhang Qing-Li  , Sun Dun-Lu  , Qiu Huai-Li  , You Jing-Lin  , Yin Shao-Tang  ,   (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

High temperature Raman spectroscopy has been used to probe the growth units existing in PbMoO4 melt. According to the Raman spectra of PbMoO4 crystal at various temperatures and the melt just above the crystal melting point, we found that Pb2+ cations and ［MoO4］2－ groups acting as the growth units exist in the melt. Further, we have studied the interaction between the growth units and various low-index planes of PbMoO4 crystal. The crystal growth habit and the cause of dendrite growth are explained. Finally, we point out that the best seed orientations for the crystal growth are parallel to its {101} planes.
An experimental study on colloidal crystals formed in two-component dispersion of charged particles
Authors: Liu Lei  , Xu Sheng-Hua  , Sun Zhi-Wei  , Duan Li  , Xie Jing-Chang  , Lin Hai  ,   中国科学院力学研究所国家微重力实验室，北京  100080
Published: December 2020

Characterization of colloidal crystals composed of two types of polystyrene particles of different sizes (94 nm and 141 nm respectively) at different number ratios is studied by means of Kossel diffraction and reflection spectra technique. The results showed the dependence of the mean interparticle distance (D0) and crystal structure on the number ratio of the two types of particles. The formation time of crystals lengthens as the number ratio of the two components approaches 1∶1. When the number ratio (9 4nm∶141 nm) decreases, the mean interparticle distance (D0) becomes larger. This study also shows that when the above number ratio equals 5:1, superlattice structure appears in the binary colloidal system.
A lidar system for monitoring planetary boundary layer aerosol in daytime
Authors: Zhang Gai-Xia  , Zhao Yue-Feng  , Zhang Yin-Chao  , Zhao Pei-Tao  ,   (1)北京理工大学信息科学技术学院，北京  100081; (2)山东师范大学物理与电子科学学院，济南  250014；中国科学院安徽光学精密机械研究所大气光学重点实验室，合肥  230031; (3)中国科学院安徽光学精密机械研究所大气光学重点实验室，合肥  230031
Published: December 2020

Lidar is a powerful tool for atmospheric monitoring. However, most lidars operate only in nighttime due to the interference of strong background skylight in daytime. We have developed the AML-1 lidar system, which can measure aerosol profiles in daytime also. In this paper, the structure and specifications of the lidar system are described. Various noise sources of the lidar and methods for rejecting these noises are discussed. It has been found that among these noises the sky radiation is the main background noise for daytime working lidars. This noise can be effectively eliminated by incorporating small divergence-angel of emitting laser beam, narrow-field-of-view receiver, and narrow-band filter with high transmittance. Some daytime boundary layer aerosol profiles measured by the AML-1 are presented.
Progress in the study of physic-optics characteristics of atmospheric aerosols
Authors: Han Yong  , Wang Ti-Jian  , Rao Rui-Zhong  , Wang Ying-Jian  ,   (1)南京大学大气科学系大气环境研究中心，南京  210093; (2)南京大学大气科学系大气环境研究中心，南京  210093；中国科学院合肥物质科学研究院安徽光学精密机械研究所大气光学研究中心，合肥  230031; (3)中国科学院合肥物质科学研究院安徽光学精密机械研究所大气光学研究中心，合肥  230031
Published: December 2020

Atmospheric aerosol particles, as one of the important members in the earth atmosphere, can influence the radiative transfer from violet and visible light to infrared in a wide wave band. On one hand, by scattering and absorption of electromagnetic waves, they can induce the energy attenuation of light waves; on the other hand, by turning the absorbed energy into the heat energy, they can heat up the atmosphere. This process directly or indirectly plays an important role in the simulation of radiate climate effect, the propagation of laser atmosphere, the high resolution spectrum, the ground and space remote sensing, the atmospheric correction, the environmental monitoring, the target detection and identification, and the overland traffics, aviation and navigation. We review the study of physics-optics characteristics of atmospheric aerosols, aiming at providing a reference for further study of atmospheric aerosols.
The characteristics of a new two mode composite coordinate representation and its application
Authors: Xu Shi-Min  , Jiang Ji-Jian  , Li Hong-Qi  , Xu Xing-Lei
Published: December 2020

In order to solve dynamic problems of double non-identical quantum harmonic oscillators with interaction potential and movement coupling, the new two mode composite coordinate representation |η1，η2〉 is proposed by the technique of integration within an ordered product of operators. The two mode squeezing operator U is constructed, and its characteristics are analyzed. Moreover, its application to double non-identical quantum harmonic oscillators with interaction potential and movement coupling is presented for solving some the dynamic problems. Approach of solving some the dynamic problems involving complicated quantum harmonic oscillators is proposed.
An approach to phase space reconstruction from multivariate data based on data fusion
Authors: Cong Rui  , Liu Shu-Lin  , Ma Rui
Published: December 2020

To cope with the problem of phase space reconstruction from univariate time series and multivariate time series, the novel approach to phase space reconstruction from multivariate data based on data fusion is presented in this paper. According to Bayes estimation theory, the phase points in the same phase space reconstructed from multivariate data are fused, then an optimal fusion phase space could be determined. The approach is applied to multivariate phase space reconstructions of Lorenz system and Rssler system, respectively. Compared with the figures reconstructed from univariate datas, the information reconstructed from multivariate data includes the main characters of all univariate data and represents the comprehensive information of system attractor, which makes the phase space reconstructed more abundant. At last, the approach is applied to multivariate phase space reconstruction of oil film whirling in the rotor system. The information reconstructed includes all the characters of the system, which improves the veracity for fault diagnosis. So all the analysis further shows that the approach presented here is effective.
Study on the regularity of predictability limit of chaotic systems with different initial errors
Authors: Ding Rui-Qiang  , Li Jian-Ping
Published: December 2020

The predictability limits of the Logistic map and Lorenz system as functions of initial error are calculated by employing the nonlinear error growth dynamics. It is found that there exists a linear relationship between the predictability limit and the logarithm of initial error. It is revealed by the theoretical analysis under the nonlinear error growth dynamics that the growth of average error will enter the nonlinear growth phase after the error reaches a certain critical magnitude and will finally reach saturation. For a given chaotic system, if the control parameters of the system are given, then the saturation of error growth is determined. Therefore, the predictability limit of the system only depends on the initial error. This is different from the linear error growth dynamics, under which the predictability time scale of chaotic system also depends on the upper limit of forecast error. In the linear expression between the predictability limit and the logarithm of initial error, its linear coefficient is relevant to the largest global Lyapunov exponent of chaotic system. If the largest global Lyapunov exponent and the predictability limit corresponding to a fixed initial error are known, the predictability limit corresponding to other initial errors can be extrapolated by the linear function expression between the predictability limit and initial error.
A family of multi-scroll chaotic attractors and its circuit design
Authors: Luo Xiao-Hua  , Li Hua-Qing  , Dai Xiang-Guang
Published: December 2020

A method to generate multi-scroll chaotic attractors and its circuit design are proposed. It uses several subsection-linear-functions to construct the nonlinear function of chaotic system. By constructing different numbers of subsection, different numbers of scroll chaotic attractors can be obtained. Numerical simulation and EWB simulation results confirm the availability of the method.
The synchronization of spatiotemporal chaos of unilateral coupled map lattice
Authors: Lü Ling  , Li Gang  , Chai Yuan
Published: December 2020

Coupled map lattices are taken as examples to study synchronization of spatiotemporal chaotic systems. Based on Lyapunov stability theory, global synchronization of two unilateral coupled map lattices is realized through appropriate choice of driving functions. Simulation results show the effectiveness of the method. The effect of control parameters on the rate of synchronization is further discussed. Simulation results also show that synchronization can also be realized when there is a systematic bias and system noise, which shows that the method has certain anti-jamming capability.
Anti-control of chaos in Bose-Einstein condensate
Authors: Wang Zhi-Xia  , Zhang Xi-He  , Shen Ke
Published: December 2020

We present a method of anti-control of chaos in Bose-Einstein condensate by applying periodic signals to convert the periodic state into chaotic state. Numerical simulation shows that there are different chaotic orbits corresponding to different modulation intensity and modulating frequency only if the maximum Lyapunov exponent of the system is positive. The phase difference between the two sinusoidal forces added to the Gross-Pitaevski equation plays an important role in anti_control of chaos.
Method and experiment of channel selection for high spectral resolution data
Authors: Du Hua-Dong  , Huang Si-Xun  , Shi Han-Qing
Published: December 2020

The concept of atmospheric retrievable index (ARI) is introduced to provide the criterion for channel selection. The definition of ARI is given by 1min the ratio of the determinant of the covariance matrix of the error of the results and the covariance matrix of the error of the background, and the value is within the interval between 0 and 1. For all the probable subsets, the one giving the greatest ARI is the subset to be selected. To illustrate the implementation and effect iveness of the method, two series of channel selection experiments of IASI for retrieval atmospheric temperature and humidity profiles using physical retrieval method are carried out. The results of the experiments show that the method can provide an effective approach to the channel selection for the application of high spectral resolution data.
Terahertz time-frequency analysis with Gabor wavelet-transform
Authors: Deng Yu-Qiang  , Lang Li-Ying  , Xing Qi-Rong  , Cao Shi-Ying  , Yu Jing  , Xu Tao  , Li Jian  , Xiong Li-Min  , Wang Qing-Yue  , Zhang Zhi-Gang
Published: December 2020

We applied different shaping factors of Gabor wavelet for the analysis of terahertz time-domain spectroscopy with wavelet_transform. Gabor wavelet analysis allows a convenient switching between time domain and frequency domain by varying shaping factors. The comparison of absorption spectral lines obtained between with wavelet-transform and with other methods demonstrated that wavelet-transform is a reliable technique for the analysis of the absorption properties and the extraction of the characteristic spectral lines in terahertz range.
Carrier-envelope phase measurement and stabilization of amplified Ti:sapphire femtosecond laser pulses by spectral interferometry
Authors: Zhu Jiang-Feng  , Du Qiang  , Wang Xiang-Lin  , Teng Hao  , Han Hai-Nian  , Wei Zhi-Yi  , Hou Xun
Published: December 2020

Carrier-envelope phase stabilization of amplified femtosecond laser pulses is demonstrated. An octave spanning white-light super-continuum is generated in a sapphire plate. Spectral interference was achieved between the blue component and the second harmonic of the red component of the super-continuum. Carrier-envelope phase information was extracted from the interference through Fourier transform and the phase was stabilized by refined modulation of pumping power of the oscillator through a phase locking loop. The root-mean-square value of the carrier-envelope phase locking error is lower than 80 mrad within the locking time of 3h.
Experimental study on the shock Hugoniot relationship and the Grüneisen-type equation of state for C30 concrete
Authors: Wang Yong-Gang  , Zhang Yuan-Ping  , Wang Li-Li
Published: December 2020

The shock properties of C30 concrete with initial porosity is investigated by gas gun planar impact technique. The manganin pressure gauge is used to measure the pressure-time curves of the samples. It is shown by the experimental studies on the shock Hugoniot relationship and the Grüneisen-type equation of state for C30 concrete that the D-u shock Hugoniot relationship is described by the linear relation, and the material parameters in the Grüneisen-type equation of state are determined. Moreover, it is observed from the measured pressure-time curves that the rate-sensitivity of dynamic response for C30 concrete is not negligible, showing marked stress relaxation and dissipation.
Effects of additional element on the glass forming ability and corrosion resistance of bulk Zr-based amorphous alloys
Authors: Zhang Hui  , Zhang Guo-Ying  , Yang Shuang  , Wu Di  , Qi Ke-Zhen
Published: December 2020

By using the real-place recursion method， bulk Zr-based amorphous alloys with effects of additional element Nb，Ta，Y，La on the glass forming ability and corrosion resistance were studied. The atomic structure model of primary precipitation phase Zr2Ni in Zr-based amorphous alloys were constructed by computer programming. The icosahedron cluster in Zr-based amorphous alloys was simulated by using the icosahedral cluster in Zr2Ni primary precipitation phase. The local density of states (LDOS) curves of Zr，Ni (before substitution) and alloying elements (after substitution) at the center or the corner of icosahedron cluster， the total bond order integral between the centered Ni atom and it's nearest neighbor (Zr，Nb，Ta，Y，La) in the icosahedron cluster， and the Fermi energy levels of the icosahedron cluster (before and after alloying elements' substitution) were calculated. The LDOS calculation results showed that the Cu atom occupies the center site of the icosahedral cluster， Nb， Ta， Y， La atoms occupy the site of Zr atom at the corner in Ni-Zr icosahedral clusters. The bond order integer calculation results suggest that Y increases the glass forming ability (GFA) of Zr-base amorphous alloys， Nb and Ta decreased the GFA， and La has little influence on the GFA. The calculated Fermi energy levels suggest that Nb， Y， La make Zr-based amorphous alloys easy to be passivated and improve the Zr-based amorphous alloys corrosion resistance. Ta has little influence on the corrosion resistance of the alloys. Therefore， Y and La are most effective on improving the GFA and corrosion resistance of Zr-based amorphous alloys. By addition of small amounts of Y and La， new bulk amorphous alloys with good corrosion resistance can be prepared.
Enhancing ultraviolet photoresponse of ZnO nanowire device by surface functionalization
Authors: Huang Jin-Hua  , Zhang Kun  , Pan Nan  , Gao Zhi-Wei  , Wang Xiao-Ping
Published: December 2020

Single ZnO nanowire ultraviolet (UV) photodetector has been fabricated， and the enhancement of its UV photoresponse by polystyrene sulfate surface functionalization has been investigated. It is found that， under the same UV light irradiation， UV photoresponse of the detector with surface functionalization increases by three orders of magnitude as compared to that without surface coating. By comparing I-V characteristics of the detectors， we find that the dark conductance of the device can decrease by three orders of magnitude after surface coating while the light conductance shows little variation. The result demonstrates that one can readily enhance the UV photoresponse of the photodetector by surface functionalization.
Rashba effect in PbTe/PbSrTe asymmetric quantum wells
Authors: Xu Tian-Ning  , Wu Hui-Zhen  , Sui Cheng-Hua
Published: December 2020

Recently， spin effect in narrow gap semiconductor heterostructures has attracted much attention. However， Rashba spin effect is quite different in Ⅳ-Ⅵ asymmetric quantum wells (QWs) with various growth orientations due to their multivalley and anisotropic band structures. In this work， we calculated Rashba splitting in Pb1-ySryTe/PbTe/Pb1-xSrxTe asymmetric QWs with growth orientations ［100］， ［110］ and ［111］. The results show that Rashba splitting reaches the maximum of 2.2meV when the well width of PbTe QWs with growth orientation ［100］ is 5.0nm， and two groups of Rashba splitting is obtained in PbTe and QWs with growth orientations ［110］ and ［111］， respectively， because the quantum confinement lifts off the fourfold degeneracy of the L-energy valleys. The dependences of Rashba splitting on asymmetry of QWs， well width， temperature and k∥ (the wave vactor in the plane) are also investigated. Large Rashba spin splitting may make Ⅳ-Ⅵ asymmetric QWs as a material candidate for spintronic devices.
Influence of iron doping level upon magnetoelectric coupling in BaTi1-zFezO3+δ-Tb1-xDyxFe2-y bilayer composites
Authors: Gao Jian-Sen  , Zhang Ning
Published: December 2020

Perovskites BaTi1-zFezO3+δ with doping level from 0.005 to 0.02 have been synthesized with sol-gol method. The X-ray diffraction shows that the doped perovskites retain the original tetragonal structure. Defferential thermal analysis demonstrates that both the transformation temperature of ferroelectric to paraelectric and the latent heat of the transformation decrease with increasing doping level. Bilayer composites BaTi1-zFezO3+δ-Tb1-xDyxFe2-y bilayer composites havebeen fabricated after the piezoelectrics being poled and their magnetoelectric effect has been investigated using a bias magnetic field and an ac magnetic field of 100Hz. The experimental result shows that the transverse magnetoelectric voltage coefficient of the bilayer composites can reach a maximum at doping level of 1.5%. The value of the maximum is 1788mV/A under a bias magnetic field of 60kA/m at room temperature. The analysis of magnetoelectric spectroscopy also shows a higher resonance peak and a higher resonance frequency for the sample containing BaTi0.985Fe0.015O3+δ， suggesting a higher piezoelectric coefficient in the doped BaTiO3 and some difference in interfacial coupling coefficients in the bilayer composites containing the doped samples， respectively.
Study of solid state cathodoluminescence in organic phosphors
Authors: Dong Qian  , Zhao Su-Ling  , Xu Zheng  , Zhang Fu-Jun  , Li Yuan  , Song Dan-Dan  , Xu Xu-Rong
Published: December 2020

The devices with sandwiched structure are prepared by compounding tris (2-phenylpyridine) iridium (Ir(PPY)3) with SiO2. The green emission of Ir(PPY)3 at 517nm and blue electroluminescence at 435nm are obtained from the devices under AC voltage. Both the green and the blue emission are attributed to the solid-state cathodoluminescence (SSCL) of Ir(PPY)3 excited by hot electrons which are accelerated in SiO2. Phosphorescent SSCL is confirmed after the realization of SSCL on organic polymers and organic small molecules tris-(8-quinolinolato)aluminum (Alq3).
Soot volume fraction and temperature reconstruction model research for asymmetric diffusive C-H flame
Authors: Huang Qun-Xing  , Liu Dong  , Wang Fei  , Yan Jian-Hua  , Chi Yong  , Cen Ke-Fa
Published: December 2020

Non-intrusive soot volume fraction and temperature distribution reconstruction scheme was proposed based on the approximations of flame emission transfer model according to tomographic principle. Radiative sensor number and arrangement specifications were determined by lease square QR matrix factorization algorithm. Simulations show that the maximum discrepancies of temperature and fraction reconstructions are 0.2% and 2.5% respectively when four 320-pixel line-scan charge-coupled device sensors were arranged non-symmetrically. According to the anti-noise capability assessments， the signal-to-noise ratio of the detectors should be larger than 60 dB in order to get reasonable results when the proposed method is adopted.
Numerical simulation and hydraulic experiment of horizontal centrifugal casting
Authors: Song Nan-Nan  , Wu Shi-Ping  , Luan Yi-Kun  , Kang Xiu-Hong  , Li Dian-Zhong  ,   (1)哈尔滨工业大学材料科学与工程学院，哈尔滨  150001; (2)中国科学院金属研究所，沈阳材料科学国家（联合）实验室,沈阳  110016
Published: December 2020

A mathematic model of mold filling and solidification in horizontal centrifugal casting is built up. Based on this model, the temperature field and the flow field in horizontal centrifugal casting are numerically simulated. The hydraulic experimental results are compared with numerical simulations, indicating that the mathematic model is accurate. Experimental results show that liquid fills the mold in the manner of a spiral trajectory in the centrifugal casting process. The filling pattern tends to be more uniform with the increase of rotational speed. The present study has a guiding significance to the production of horizontal centrifugal casting roll.
The plane strain theory for one-dimensional hexagonal quasicrystals in aperiodical plane
Authors: Liu Guan-Ting  , He Qing-Long  , Guo Rui-Ping  ,   (1)内蒙古师范大学数学科学学院，呼和浩特  010022; (2)内蒙古师范大学数学科学学院，呼和浩特  010022；兴安职业技术学院数学系，乌兰浩特  137400; (3)装备指挥技术学院基础部，北京  101416
Published: December 2020

Considering the plane elastic problem of one-dimensional hexagonal quasicrystals with point group 6mm, the theory about plane strain parallel to aperiodic direction is proposed and established. As an application of this theory, the analytic solutions of elastic fields of the quasicrystals with an elliptical cavity perpendicular to quasi-periodical direction are given in the form of general complex variable. In the limit case, our solutions degenerate into the ones of crack problems.
Evolution of interphase misfit dislocation networks in Ni-based single-crystal superalloy
Authors: Zhu Tao  , Wang Chong-Yu  , Gan Yong  ,   (1)钢铁研究总院功能材料研究所，北京  100081; (2)钢铁研究总院功能材料研究所，北京  100081；清华大学物理系，北京  100084
Published: December 2020

The molecular dynamics simulations are used to study the characteristics of misfit dislocation networks in the γ/γ′ phase interface of a Ni-based single-crystal superalloy. From the analyses of the formation of interphase dislocations, the reaction of dislocations, and the evolution of dislocation networks, we find that the shape of the dislocation network finally evolves into a regular hexahedron from an original tetradedron.
Deposition process of MgO thin film on MgO（001） surface simulated by molecular dynamics
Authors: Liu Mei-Lin  , Zhang Zong-Ning  , Li Wei  , Zhao Qian  , Qi Yang  , Zhang Lin  ,   (1)东北大学理学院，沈阳  110004; (2)沈阳工业大学理学院，沈阳  110178
Published: December 2020

Molecular dynamics is used to simulate the deposition process of MgO molecules on MgO（001） surface，and substrate temperature and molecular incident energy are discussed in terms of their effects on the diffusivity of MgO molecules and the substrate surface coverage ratio. The simulated results show that with the substrate temperature increasing， vacant sites in MgO film decrease, owing to the increase in diffusivity of the deposited molecules on the substrate. At low temperatures， the substrate surface coverage ratio increases with molecular incident energy increasing. At high temperatures， the surface coverage ratio reaches the maximum at an incident energy of 3.0 eV， and then it decreases with the increase of incident energy.