bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and study on epitaxial Pb(Zr0.52Ti0.48)O3 ferroelectric films on different substrates
Authors: Li Jian-Kang  , Yao Xi  ,   (1)苏州科技学院电子与信息工程系,苏州  215011; (2)西安交通大学电子材料研究所,西安  710049
Published: December 2020

LaNiO3 (LNO) thin films were successfully prepared on Si (100) and Pt /Ti/SiO 2/Si substrates by metalorganic decomposition (MOD). Pb(Zr0.52Ti0.48)O3（ＰZＴ） thin films were prepared on the Pt( 111)/Ti/SiO2/Si, LNO/Si (100) and LNO/Pt(111)/Ti/SiO2/Si substrates by a modified sol-gel met hod. The crystallographic orientation and the microstructure of the resulting PZT thin f ilms on the different substrates were characterized by x_ray diffraction and sca nning electron microscopy. The dielectric and ferroelectric properties of PZT fi lms on the different substrates are discussed. The PZT films deposited on LNO/Pt /Ti/SiO2/Si and LNO/Si（100） substrates show strong ［100］ preferre d orient ation, while the films deposited on Pt/Ti/SiO2/Si substrates show ［1 10］ ori entations. PZT films on LNO/Pt/Ti/SiO2/Si and LNO/Si(100) substrates have lar ger average grain sizes, dielectric constant and remnant polarizations compared with those grown on Pt/Ti/SiO2/Si substrates.
A new method for analysis of electro-optic detection for THz radiation
Authors: Zheng Guo-Liang  , Wu Dan-Dan  , She Wei-Long  ,   中山大学光电材料与技术国家重点实验室,广州  510275
Published: December 2020

A new method for description of electro-optic detection for THz radiation, using wave coupling theory of linear electro-optic effect,is presented in this paper. This method is not only useable in all optically isotropic detection crystals,bu t also usable in the situation that the probe beam propagates along the optical axis of uniaxial crystals.Also,the description method can be used for all possib le polarization directions of the probe beam and for arbitrary direction of the electric field of THz radiation.The description does not need complex coordinate transform,and the calculation is very simple.Finally,some conclusions have been drawn.
First-principle study on GaN(1010) surface structure
Authors: Li Yong-Hua  , Xu Peng-Shou  , Pan Hai-Bin  , Xu Fa-Qiang  , Xie Chang-Kun  ,   中国科学技术大学国家同步辐射实验室,合肥  230029
Published: December 2020

We have calculated the atomic and electronic structures of the non-polar surface of GaN(1010) by employing the full potential augmented plan wave and local orbital method (APW+lo). The calculated lattice constant and bulk modulus of zinc-blend GaN crystal are in excellent agreement with the experimental dat a. Using the slab and supercell model, we find that the surfae is characterized by a top-layer bond-lenth-contracting rotation relaxation. The surface Ga atom moves inward with 0014nm and form a planar sp2-like bonding with its three N neighbors. While the surface N atom moves outward with 0013nm and tends to a taper p3-like bonding with its three Ga neighbors. The surface layer rotation angle is 85°. From the calculated results of the desity of states of GaN (1010) surface we find that the surface relaxation induces the transformation from s emi-metallic to semi- conducting characteristic. Furthermore, it is also shown t hat the surface charges have a large transfer, and the surface bonds have a rehy bridization, which makes the ionicity reduce and the covalence increase, we beli eve that it causes the surface bond shortening and rotating.
Maser instability driven by an electron beam with losscone-beam distribution
Authors: Chen Yan-Ping  , Wang Chuan-Bing  , Zhou Guo-Cheng  ,   (1)中国科学技术大学地球和空间科学学院，合肥  230026; (2)中国科学院国家天文台，北京  100012;中国科学院物理研究所，北京  100080; (3)中国科学院空间科学和应用研究中心，北京  100080
Published: December 2020

The studies of the main characterestics of the maser-instability driven by elec trons with a losscone-beam distribution are carried out on the basis of the the oretical model of Chen et al (2002, Phys. Plasmas 9,2816; 2003, Acta Phys. S in.52,421). This kind of electrons may be created by the reconnection near the chromosphere of the sun. The electrons have the characters of both losscone and beam. The results show that it can excite the fundamental and harmonic radiatio n of extraordinary and ordinary modes in an appropriate region of plasma freque ncy over the gyrofrequency with the characters of both losscone and beam distri bution, and with much stronger growth rate. It enriches the fundamental content of the plasma instabilities. It is expected to be applicable widely in the stud y of solar and celestial emission mechanism.
Calculation of the wave reflecting characteristics of magnetized plasma surface
Authors: Yang Juan  , Zhu Liang-Ming  , Su Wei-Yi  , Mao Gen-Wang  ,   西北工业大学航天学院，西安  710072
Published: December 2020

The total wave energy reflectance of the interface between the magnetized plasma before a conductor plate and the atmosphere or vacuum can be calculated by usin g the equivalent input impedance method. The result is that the reflection chara cteristics can be affected by electron numerical density, magnetized plasma thic kness, incidence wave frequency and magnetic intensity. Magnetic field can reduc e wave energy reflectance obviously only when the electron numerical density is of an appropriate value. The increased frequency of the incident wave must accom pany the augmented magnetic intensity, which is the condition that magnetized pl asma will absorb more energy of the electromagnetic wave.
The measurement and analysis of the prolonged lifetime of the plasma channel formed by short pulse laser in air
Authors: Dong Quan-Li  , Yan Fei  , Zhang Jie  , Jin Zhan  , Yang Hui  , Hao Zuo-Qiang  , Chen Zheng-Lin  , Li Yu-Tong  , Wei Zhi-Yi  , Sheng Zheng-Ming  ,   中国科学院物理研究所光学开放实验室，北京  100080
Published: December 2020

The Tikhonov regularization method is applied to analyze the lifetime of the pl asma channel produced by femtosecond laser pulses propagating in air. Experiment s show that by using double laser pulses separated by several nanoseconds, the lifetime of the plasma channel can be prolonged by 5 times that of only using o ne laser pulse.
Multifractal spectra of growing clusters in nanoscale characterized by small angle x-ray scattering
Authors: Shao Yuan-Zhi  , Zhong Wei-Rong  , Ren Shan  , Cai Zhi-Su  , Gong Lei  ,   中山大学理工学院物理系，广州  510275
Published: December 2020

Small angle x-ray scattering (SAXS) method was adopted to investigate the characteristics of growth fractal of two sorts of typical nanoscaled clusters, i.e. g rowing in both ultrafine Ni powders synthesized by chemical reaction and Finemet (Fe73.5Cu1Nb3Si13.5B9) a morphous ribbon by physical crystal lization annealing. The SAXS measurement discloses definitely the existence of d istinct mass multifractal patterns within ultrafine Ni granules and crystallizin g Finemet ribbon. The multifractal spectra of the clusters mentioned above sugge st the occurrence of inhomogeneous distribution of constituent elements and grow th fractal during the formation of those nanoscale clusters. The multifractal sp ectra of ultrafine Ni powders prepared using a variety of procedures take on an obvious difference in shape, indicating the substantial influence of preparation process on diffusion of constituent elements and the growth mechanism of cluste rs. The crystallization annealing processes, however, affect the multifractal sp ectra of Finemet alloy slightly.
Influence of electron-phonon interaction on single electron tunneling in a quantum dot molecule
Authors: Wu Zhuo-Jie  , Zhu Ka-Di  , Yuan Xiao-Zhong  , Zheng Hang  ,   上海交通大学物理系，上海  200240
Published: December 2020

The dynamics of electron tunneling between double quantum dots is investigated t heoretically in terms of a perturbation method based on a unitary transformation . Considering electron coupling with phonons, the dynamical tunneling current is obtained analytically. The phonon-induced decoherence is studied in detail. A possible decoupling mechanism is proposed.
Magnetoresistance effect of double-barrier magnetic tunneling junction applied in spin transistors
Authors: Zeng Zhong-Ming  , Han Xiu-Feng  , Du Guan-Xiang  , Zhan Wen-Shan  , Wang Yong  , Zhang Ze  ,   (1)中国科学院物理研究所（凝聚态物理国家实验室) 磁学国家重点实验室，100080   北京; (2)中国科学院物理研究所(凝聚态物理国家实验室) 先进材料与结构分析电镜实验室,100080  北京
Published: December 2020

The multilayer films of the double-barrier magnetic tunneling junctions (DBMTJs) were deposited by magnetron sputtering. The AlOx insulator was forme d by plasma oxidizing aluminium. The photolithographic pattering procedure combin ed with Ar ion milling was used to microfabricate the DBMTJs with an ellipse of 　π×３×６μm2. Magnetic transport properties of DBMTJs were invest igate d. The junctions show a resistance-area product about 136 kΩ·μm2 and 175 kΩ·μm2, a high tunneling magnetoresistance of 27% and 422% at 3 00 K and 42 K, respectively. A tunneling magnetoresistance oscillation phenome non with respect to the bias voltage was first observed in this experiment. We d esigned a few kind of spin transistors based on the spin-dependent resonant tunn eling effect of the DBMTJs.
Magnetism and transport properties of Heuser alloy Cu2VAl
Authors: Wang Ben-Yang  , Qian Zheng-Nan  , Sui Yu  , Liu Yu-Qiang  , Su Wen-Hui  , Zhang Ming  , Liu Zhu-Hong  , Liu Guo-Dong  , Wu Guang-Heng  ,   (1)哈尔滨工业大学凝聚态科学与技术研究中心,哈尔滨  150001; (2)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

We have investigated magnetic and transport properties of Heusler alloy Cu2 VAl. Magnetic measurements confirm that the magnetic transition from ferro magn etism to paramagnetism arises near 210K for Cu2VAl sample, which is a weak ferromagnet. Resistance curves show that there is a small jump of 1% in resista nce caused by the localized impurity superconduction phase transition around 7K. The scattering between electron-phonon is the main scattering mechanism. Furthe rmore, extraordinary Hall effect exists for side jump at temperatures below T C and the phase transition leads to Hall resistivity changing abnorma lly at 7K.
The spin excitation delay for granular film swith ferromagnetic granules
Authors: Wu Qiang  , Zheng Rui-Lun  ,   (1)西南师范大学物理学院，北碚  400715; (2)渝西学院物理学与电子信息工程系，永川  402168
Published: December 2020

With the s-d commutative operation model and under the condition of the approximate single-loop of s-d commutative reciprocity for spin Green functio n, we worked out the spin excitation delay for granular films with ferromagnetic granules, and using the (α-C:H)1-xCox granular film as a n ex ample, we explored the rules that spin excitation delay changes with temperature . As a result, the process of the spin excitation delay through spin-polarized excitation is not related to temperature; however, the process through thermal e xcitation is temperature-dependent.
Coercivity mechanism of segmented (A/B)m composite nanowire arrays
Authors: Shi Hui-Gang  , Si Ming-Su  , Xue De-Sheng  ,   兰州大学 磁学与磁性材料教育部重点实验室，兰州  730000
Published: December 2020

Based on the symmetric fanning mechanism of the sphere-chain model,a systematic study on the hysteresis loops for hexagonal arrays of segmented composite magnetic nanowires fabricated by electrochemical deposition is performed by taking into account the interfacial exchange coupling effect between the segments. The coercivity variation rule with the change of the segments is presented. It is found that the exchange coupling effect between the segments plays an important role for magnetization reversal in the segmented composite nanowire arrays.
Effects of the technology of implanting nitrogen into buried oxide layer on the characteristics of partially depleted SOI nMOSFET
Authors: Zheng Zhong-Shan  , Liu Zhong-Li  , Zhang Guo-Qiang  , Li Ning  , Fan Kai  , Zhang En-Xia  , Yi Wan-Bing  , Chen Meng  , Wang Xi  ,   (1)中国科学院半导体研究所微电子研究与发展中心,北京  100083; (2)中国科学院半导体研究所微电子研究与发展中心,北京  100083;济南大学物理系，济南 250022; (3)中国科学院上海微系统与信息技术研究所,上海  200050
Published: December 2020

The effects, caused by the process of the implantation of nitrogen in the buried oxide layer of SIMOX wafer, on the characteristics of partially depleted silicon_on_insulator nMOSFET have been studied. The experimental results show that the channel electron mobilities of the devices fabricated on the SIMON (separation by implanted oxygen and nitrogen) wafers are lower than those of the devices made on the SIMOX (separation by implanted oxygen) wafers. The devices corresponding to the lowest implantation dose have the lowest mobility within the range of the implantation dose given in this paper. The value of the channel electron mobility rises slightly and tends to a limit when the implantation dose becomes greater. This is explained in terms of the rough Si/SiO2 interface due to the process of implantation of nitrogen. The increasing negative shifts of the thre shold voltages for the devices fabricated on the SIMON wafers are also observed with the increase of implanting dose of nitrogen. However, for the devices fabri cated on the SIMON wafers with the lowest dose of implanted nitrogen in this pap er, their threshold voltages are slightly larger on the average than those prepa red on the SIMOX wafers. The shifts are considered to be due to the increment of the fixed oxide charge in SiO2 layer and the change of the density of the int erface-trapped charge with the value and distribution included. In particular, t he devices fabricated on the SIMON wafers show a weakened kink effect, compared to the ones made on the SIMOX wafers.
Resonance enhancement of the endohedrally confined hydrogen-like system
Authors: Wang Xiao-Feng  , Qiao Hao-Xue  , Liu Hai-Lin  , Yu Guo-Ping  ,   武汉大学物理系,武汉  430072
Published: December 2020

Using B-spline method, we take Be3+ in buckyminister fullerence as a n example and have calculated the 2s—3p oscillator strength of the endohedrally confined hydrogen-like system in the confining well with different shapes and l ocations. Resonance enhancement appears as the 2s and 3p states are both bound i n outer well, and a resonance enhancement peak has been found at the “collapse point”. Our results show that resonance enhancement is insensitive to the shape of the confining well, and it is also influenced by confinement ability. The lo cation of the confining well may strongly affect the resonance enhancement.
Improvement of the measuring precision by changing the pulse sequence in the three-level atom gravimeter
Authors: Zheng Sen-Lin  , Chen Jun  , Lin Qiang  ,   浙江大学物理系, 杭州  310027
Published: December 2020

We introduced a method that can improve the measurement precision of the three-level atom gravimeter by changing the sequence of the pulses. A 3×3 matrix is put forward to describe the propagation of atomic beams, the interaction between the three-level atoms and bichromatic laser fields, and to calculate the phase difference of the atom interferometers. We obtained also the relation between g ravity and the phase difference of the atom gravimeter. It is found that the pre cision of the three-level atom gravimeter can be increased simply by change the sequence of the optical pulses.
Study on the structures and properties of small Pd-Y clusters
Authors: Guo Jian-Jun  , Yang Ji-Xian  , Die Dong  , Yu Gui-Feng  , Jiang Gang  ,   (1)四川大学原子与分子物理研究所，成都  610065; (2)西华大学应用物理研究所，成都  610039
Published: December 2020

The possible geometrical and electronic structures of small Pd-Y clusters including Pdn（n=2,3,4）,Yn（n=2,3,4）, PdYn（n=2,3, 4）, PdnY(n=1,2,3,4) and Pd2Yn（n=2,3,4） have been optimized by density functional theory method with a relativistic effective core potentia l(RECP) using Gaussian 98 code. Due to the Jahn-Teller effect, the ground states of Pd4 and Y4 belong to Cs, while the symmetry is C2v for P d3 and Y3. The ground states of Pd3Y, Pd4Y, PdY3,PdY4 and Pd2Y4b elong to Cs. Finally, the energy level distribution, highest occupied mole cular orbit-lowest unoccupied molecular orbit gaps and the chemical activation a re investigated.
Optical image of squeezed coherent states in the parametric image amplifier
Authors: Liu Zhu-Xin  , Fang Mao-Fa  ,   湖南师范大学物理与信息科学学院，长沙  410081
Published: December 2020

The properties of the output optical image are investigated by taking squeezed c oherent states as the input image in the parametric image amplifier.Our results show that the squeezing degree and squeezing direction of the output optical ima ge can be controlled by the parametric image amplifier,namely,the increase or de crease of the squeezing degree and the change of the squeezing direction are dep endent on the parameter selection of the parametric image amplifier.
Enhanced Kerr nonlinear effect of Raman transition in a Λ-type three-level atomic system
Authors: Wu Hai-Bin  , Chang Hong  , Ma Jie  , Xie Chang-De  , Wang Hai  ,   山西大学光电研究所，量子光学与光量子器件国家重点实验室，太原  030006
Published: December 2020

We report a theoretical study of linear and nonlinear susceptibilities of Raman transition in a Λ-type three-level atomic system. In the Raman transition, if t he population of atoms is all prepared in the ground state which interacts with the control light, the linear susceptibility equals zero, while the third-order nonlinear susceptibility does not equal zero. By decreasing the nonradiative dec ay rate γ12 between the two ground states of the atoms, the Kerr no nlinear refractive index for cross-phase modulation can be significantly enhance d.
Bright amplitude-squeezed light generation by an optical parametric deamplifier in a periodically poled KTiOPO4 crystal
Authors: Ma Hong-Liang  , Wei Dong  , Ye Chen-Guang  , Zhang Jing  , Peng Kun-Chi  ,   山西大学光电研究所，量子光学与光量子器件国家重点实验室，太原  030006
Published: December 2020

We demonstrated experimentally the generation of bright amplitude-squeezed light by a continuous-wave quasi-phase-matched degenerate optical parametric deampl ifier based on periodically poled KTiOPO4The threshold of the optic al parame tric oscillator is 35mW. With the pump power of 20mW, the amplitude noise re duction of 223dB is observed directly. It is significant that the amplitude noise reduction of 217dB can be observed only at the pump power of 8mW.
Design and analysis of 1.3μm GaAs-based quantum dot vertical-cavity surface-emitting lasers
Authors: Tong Cun-Zhu  , Niu Zhi-Chuan  , Han Qin  , Wu Rong-Han  ,   中国科学院半导体研究所，北京  100083
Published: December 2020

A theoretical study on 13μm GaAs-based quantum dot vertical-cavity surface- emitting lasers (VCSELs) was made. Investigation of the influence of VCSELs on t he optical confinement factors and the optical loss and the calculation of the m aterial gain of the assembled InGaAs/GaAs quantum dots. Analysis of the threshol d characteristic was made and the multi-wavelength cavity and multilayer quantum_dot stack structure is found to be more suitable for quantum dot VCSELs.
Investigation of solubilized carbon nanotubes in optical limitation
Authors: Niu Yan-Xiong  , Zhang Peng  , He Chen-Juan  , Duan Xiao-Feng  , Yu Ye  , Yao Jian-Quan  ,   (1)解放军军械工程学院光学与电子工程系,石家庄  050003; (2)解放军军械工程学院光学与电子工程系,石家庄  050003;天津大学精密仪器与光电子工程学院，光电信息技术科学教育部重点实验室,天津   300072;中国科学院物理研究所,北京  100080; (3)天津大学精密仪器与光电子工程学院，光电信息技术科学教育部重点实验室,天津   300072; (4)中国科学院物理研究所,北京  100080
Published: December 2020

The optical limiting effect of solubilized carbon nanotubes on 1064 and 532nm laser is studied in experiment. The experiments are carried out with samples of different thickness and concentration, and the optical limiting experiments are also carried out with pure solvent (chloroform) in order to confirm that the opt ical limiting effect is due to carbon nanotubes. The results showed that the sol ubilized carbon nanotubes have good optical limiting characters to both 1064 and 532nm laser.
ESR study of the Mn2+ center in LiNbO3
Authors: Hou Bi-Hui  , Li Yong  , Liu Guo-Qing  , Zhang Gui-Hua  , Liu Feng-Yan  , Tao Shi-Quan  ,   (1)北京工业大学应用数理学院，北京  100022; (2)清华大学化学系，北京  100084
Published: December 2020

Fine structure and hyperfine structure of Mn2+ in LiNbO3 are analyzed with electron spin resonance (ESR) at room temperature. It is concluded that the zero-field splitting of energy levels of electron spin angular moment between ±12〉 and ±32〉 is Δε1=-587×10-4cm-1, and that between ±32〉 and ±52〉 is Δε2=-2633×10-4cm-1. The anisotropic La nde factors are g∥=21810，and g⊥=20937 The fine structure co nstant is D=-536×10-4cm-1, and hyperfine structure constants ar e A∥=8836cm-1 and A⊥=8120×10-4cm-1. The interaction action of the fine structure is larger than that of the hyperfine structure. In addition, it is worth paying special attention to the fact that two forbidden transitions -32〉12〉 and -12〉52〉 are found.
Study on models of strain and stress distribution in heterostructures
Authors: Wang Qing-Xue  ,   中国科学院上海技术物理研究所,上海  200083
Published: December 2020

Based on the equilibrium of combined girders, a set of models for the strain a nd stress distributions in heterostructures introduced by lattice mismatch, ther mal mismatch and the combination of the two factors are set up, and the analyti c solutions, including lattice mismatch strain, thermal mismatch strain, bending strain and the radius of curvature of the system, are also given. Furthermore, by using the models given here, strain and stress distributions in HgCdTe/CdZnTe heterostructures are calculated. The results show that both the maximum stress in HgCdTe films and the maximum stress in CdZnTe always appear at the interface between them, and that the neutral axis as a function of thickness and elastic parameters in the heterostructures are not related to lattice mismatch, lattice relaxation, thermal mismatch, and so on. In addition, the radius of curvature of HgCdTe/CdZnTe decreases with decreasing thickness of CdZnTe. In order to avoid cracking of HgCdTe/CdZnTe device at 77K, the thickness of CdZnTe must b e larger than the limited value.
Optical polarized properties for the PbWO4 crystal containing lead vacancy
Authors: Liu Ting-Yu  , Zhang Qi-Ren  , Zhuang Song-Lin  ,   (1)上海理工大学光学与电子信息工程学院，上海  200093; (2)上海理工大学理学院，上海  200093
Published: December 2020

The electronic structure, dielectric functions, complex refractive indices and absorption spectra for the polarized light from the perfect PbWO4(PWO) crystal and the PWO crystal containing V2-Pb have been calcula ted using LAPW +LDA method with lattice structure optimized. The peaks of the absorpti on spectra corresponding to the electronic transitions have been studied. The op tical properties of PWO crystal containing V2-Pb are aniso trop ic. It may be caused by the anisotropy of lattice structure of the PWO crystal. Our calculated results indicate that the perfect PWO crystal does not have absor ption band in the visible and near_ultraviolet region, but the PWO crystal conta ining V2-Pb has absorption bands in visible and near_ultra viol et region. The absorption bands can be well decomposed into four Gaussian_shape bands peaking at about 350, 405, 550 and 670 nm. It predicates that these absor ption bands are related to the existence of the V2-Pb in t he PWO crystal.
The light-stability of polycrystalline silicon films deposited at low temperatures from SiCl4/H2 mixture
Authors: Zhu Zu-Song  , Lin Xuan-Ying  , Yu Yun-Peng  , Lin Kui-Xun  , Qiu Gui-Ming  , Huang Rui  , Yu Chu-Ying  ,   汕头大学物理系，汕头  515063
Published: December 2020

We have studied the stability of amorphous silicon and polycrystalline silicon films under illumination. These films are prepared by plasma-enhanced chemical vapor deposition technology from SiH4/H2 and SiCl4/H2 separately. The exp eriment indicates that the light-soaking degradation phenomenon, which exists in almost all amorphous silicon films, does not appear in the polycrystalline sili con films. The light-dark conductivity of polycrystalline silicon films does not decrease but increase during light irradiation. Furthermore, the variance of co nductivity depends on hydrogen dilution ratio. It is suggested that the persiste nt photoconductivity effect of polycrystalline silicon films may originate from the high crystallinity and the action of chlorine.
On the difference between empirical mode decomposition and wavelet decomposition in the nonlinear time series
Authors: Gong Zhi-Qiang  , Zou Ming-Wei  , Gao Xin-Quan  , Dong Wen-Jie  ,   (1)国家气候中心气候研究开放实验室，北京  100081; (2)扬州大学物理科学与技术学院，扬州  225009;国家气候中心气候研究开放实验室，北京  100081; (3)扬州大学物理科学与技术学院，扬州  225009;中国科学院大气物理研究所，北京  100029
Published: December 2020

The method of empirical mode decomposition （EMD） based Hilbert transformation is that separate the nonlinear time series into intrinsic mode functions （IMFs ） with different time scale by using EMD, then apply the Hilbert transformation to every IMF to get the Hilbert spectrum.By systematically comparing the advan tages and disadvantages between EMD and wavelet decomposition （WD）, between Hi lbert transformation and wavelet transformation in transacting nonlinear time s eries using ideal time series and 18O time series of Guliya i ce co re on the Tibetan Plateau, we present some improving measures to reduce the di sadvantages. The result of investigation show that the combination of EMD-based and WD-based methods may be more effectively in recognizing the main informatio n of the time series.
Perturbative solution for a class of El Ni?o sea-air oscillator mechanism
Authors: Mo Jia-Qi  , Lin Wan-Tao  , Wang Hui  ,   (1)安徽师范大学，芜湖  241000; (2)中国科学院大气物理研究所，北京  100029; (3)中国气象科学研究院，北京  100081
Published: December 2020

The oscillation for a class of coupled systems in the El Nio-Southern Oscillatio n (ENSO) mechanism is studied. Using the perturbation theory and perturbative me thod, the uniformly valid asymptotic expansions of the solution for a class of E NSO model are obtained easily.
The perturbative solution for the tropic sea-air coupled oscillators
Authors: Mo Jia-Qi  , Lin Yi-Hua  , Lin Wan-Tao  ,   (1)安徽师范大学数学系，芜湖  241000; (2)中国科学院大气物理研究所，北京  100029
Published: December 2020

A class of models of equator sea-air coupled oscillators is studied. Using the perturbative method the asymptotic solution of the corresponding model is obtained.
Mei symmetry, Noether symmetry and Lie symmetry of a Vacco system
Authors: Gu Shu-Long  , Zhang Hong-Bin  ,   (1)巢湖学院物理系，巢湖  238000; (2)上海大学上海市应用数学和力学研究所，上海  200072
Published: December 2020

The Mei symmetry, i.e.the form invariance, of a Vacco system is studied. The Definition and the determining equation of Mei symmetry in the Vacco system are given. The relations among the Mei symmetry, the Lie symmetry and the Noether symmetry are studied, and the conserved quantities of the Vacco system are obtained. An example is finally given to illustrate the application of the result of this paper.
Steadiness of relatively rotation dynamics equation and it’s solution for a kind stickiness flexibility coefficient
Authors: Wang Kun  ,   燕山大学理学院，秦皇岛  066004
Published: December 2020

Establishing a kind stickiness flexibility rotation dynamics equation of the cylinder between random two cross sections,discussing steadiness of relatively rotation angle.Gaining solution for a kind stickiness flexibility coefficient because the equation is non-homogeneous ordinary differential equation group of order 2 linear of variable coefficient,and there isn't unified solution to this equation group.
A direct algebraic method to obtain solitary solutions of nonlinear differential-difference equations
Authors: Yu Ya-Xuan  , Wang Qi  , Zhao Xue-Qin  , Zhi Hong-Yan  , Zhang Hong-Qing  ,   (1)大连理工大学应用数学系，大连  116024; (2)大连理工大学应用数学系，大连  116024;曲阜师范大学数学系，曲阜  273165; (3)大连理工大学应用数学系，大连  116024;中国科学院数学机械化重点实验室，北京  100080
Published: December 2020

In this letter, we extend a direct method for constructing solitary solutions of nonlinear differential-difference equations.Hybrid lattice equations are chosen to illustrate this method.As a result, several solitary solutions are obtained with the help of Maple.This method can also be used in other nonlinear differential-difference equations.
A method for transmitted detection of lint trash and imaging target enhancement
Authors: Jia Dong-Yao  , Ding Tian-Huai  ,   (1)清华大学精密仪器与机械学系，北京  100084; (2)清华大学深圳研究生院，深圳  510000
Published: December 2020

Present methods using spectral reflected imaging for detection of lint trash suf fer from some fundamental limitation because the trash almost has the same refl ected characteristic as the lint. To effectively detect the trash in lint, a met hod using transmitted imaging technique was proposed and the experimental pheno menon was analyzed in detail. The transmitted imaging model was constructed bas ed on analyzing the trash and lint absorption characteristics. And the impacts o n imaging target by the type and energy of light source as well as thickness an d velocity of lint movement were also discussed. After analyzing the transmitted photo propagation characteristic, a method of capturing non-diffuse photo using high-speed CCD and statistic filtering processing was developed for enhancement of the imaging target. Furthermore, the relation between the exposure time of high-speed CCD and the target distinctness was determined. The result indicated that the method is effective to acquire a distinct target image using the transmitted imaging detection and imaging target enhancement. And the image is consistent with the actual target. This method not only can provide an effective way to detect the white and colorless trash in cotton, but also can be applied to other imaging system such as the infrared and other band spectral imaging. It is believed that this weak target transmitted imaging system is an effective way to detect wcak target.
Influence of intense pulse laser on penetron-atomic ionization in muon-catalysed fusion
Authors: Shi Chun-Hua  , Qiu Xi-Jun  , An Wei-Ke  , Li Ru-Xin  ,   (1)上海大学理学院物理系，上海  200436; (2)上海大学理学院物理系，上海  200436;湖南理工学院物理系，岳阳  414000; (3)中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

In this paper, the one-dimensional time-dependent Schrdinger equation is numerically solved; in muon-catalysed fusion, the influence of different laser inte nsities and wavelengths on the μ3He ionization is studied. Resul ts show t hat the ionization probability is about 2.7 percent when the magnitude of laser intensity is from 1019 to 1023W/cm2, an d can increase obviously wh en the laser intensity reaches 3.0×1024 W/cm2. Furthe rmore, the ionizat ion probability increases with the laser intensity and wavelength, that is, to e nhance the efficiency of the muon-catalysed fusion.
The tan2x potential and the eigenvalue and eigenfunction for planar channelling radiation
Authors: Luo Shi-Yu  , Shao Ming-Zhu  ,   东莞理工学院，东莞  523106
Published: December 2020

The tan2x potential is introduced to describe the interaction between a partic le and a crystal.In the frame of quantum mechanics, Schrdinger equation is red uced to the hypergeometric equation.The eigenvalues are calculated also.It is sh own that the conformity between the theory and the experiment is good.
Hartree-Fock-Slater self-consistent field calculation of electron pressure for plasmas
Authors: Zhu Xi-Rui  , Meng Xu-Jun  , Tian Ming-Feng  , Wang Zhi-Gang  , Jiang Min-Hao  ,   北京应用物理与计算数学研究所，北京  100088
Published: December 2020

On the basis of dynamic criterion for free electrons, a traditional averaged atomic model (AAM 1) is improved in several aspects. The continuum radial wave function in central field approximation is normalized in a certain boundary condition. The contributions of the free electrons are dealt with in four parts to improve the precision of electron pressure. The condition of normal density is spontaneously satisfied. As samples electron pressure of Iron, Nickel, Lead and Americium are calculated and compared with the results other theories and experiments.
Effect of one-photon detuning on light speed reduction in a three-level Λ-type atomic system
Authors: Wang Bo  , Li Shu-Jing  , Chang Hong  , Wu Hai-Bin  , Xie Chang-De  , Wang Hai  ,   (1); (2)量子光学与光量子器件国家重点实验室，山西大学光电研究所，太原  030006
Published: December 2020

We have observed the reduction of group velocity of light via electromagnetically induced transparency (EIT) and measured the dependence of pulse delay on the one-photon detuning in a three-level Λ-type atomic system. The results show that due to the effect of Doppler broadening the light speed reduction is signif icant in a range of ±600MHz one-photon detuning. Under the condition of consid ering the Doppler shift of frequency, the pulse delay as a function of the one-p hoton detuning is numerically calculated. The experimental measurements are in g ood agreement with the theoretical results. These researches provide theoretical and experimental references for controlling the group velocity of light by mean s of one-photon detuning.
High polarization properties of single-photon emission from anisotropic InGaAs quantum dots
Authors: Zhou Hui-Jun  , Cheng Mu-Tian  , Liu Shao-Ding  , Wang Qu-Quan  , Zhan Ming-Sheng  , Xue Qi-Kun  ,   (1)武汉大学物理系，武汉  430072; (2)武汉大学物理系，武汉  430072;中国科学院物理研究所，国际量子结构中心，北京  100080; (3)中国科学院武汉物理与数学研究所，武汉  430071; (4)中国科学院物理研究所，国际量子结构中心，北京  100080
Published: December 2020

The high-polarized single-photon emission in single anisotropic InGaAs quantum d ots excited by linear pulse excitation was discussed. The expression of the pola rization and cross relaxation between two orthogonal eigenstates was given. It w as revealed that the cross relaxation increased with intensity of the excitation , which resulted in the decrease of polarization factor with the input pulse a rea.
Threshold of stimulated Brillouin scattering pumped by a multi-longitudinal mode laser
Authors: Lin Dian-Yang  , Gao Hong-Yan  , Wang Shuang-Yi  , Jiang Xiao-Cun  , Lü Zhi-Wei  ,   哈尔滨工业大学可调谐激光技术国家级重点实验室,哈尔滨  150001
Published: December 2020

On the basis of the multi-longitude theory of stimulated Brillouin scattering (S BS), a group of coupling wave equations without limitation to the mode separatio n of a laser was deduced while the random initial phases of the multi-longitudin al modes were introduced for SBS pumped by a free-operating laser. The dependenc es of broadband SBS threshold on the bandwidth of the laser, the number of the l aser modes, the mode separation of the laser, the linewidth of Brillouin, and th e ratio of the SBS interaction length to the laser coherence length were discuss ed in detail. And the theoretical results were consistent with the experimental results reported.
Dual extraction and collection of ions by parallel electrode method
Authors: Song Xiao-Peng  , Chen Rong  , Bao Cheng-Yu  , Wang De-Wu  ,   清华大学工程物理系激光实验室，北京  100084
Published: December 2020

Ion extraction from laser-induced plasma is one of the key problems in atomic vapor laser isotope separation (AVLIS) engineering. In an electrostatic field, the plasma potential is higher than both electrodes due to the plasma shield effect. And sheaths exist on both sides of the electrodes. Using numerical simulation, it has been proven that ions can be extracted by the positive electrode. In conventional ion extraction experiments using an electrostatic field, the ions are only collected at the negative electrode. We focused on the positive electrode as well as the negative collector in our experiments. The Faraday cups, fix ed on both electrodes, were used to collect the extracted ions and avoid the eff ect of power supply. As a result, the positive electrode can also extract ions. The collection ratio of positive and negative collectors decreases, as the appli ed voltage increases.
Acceleration of a pre-accelerated electron by an ultra-short and ultra-intense laser pulse in vacuum
Authors: He Feng  , Yu Wei  , Xu Han  , Lu Pei-Xiang  ,   (1)激光技术国家重点实验室，华中科技大学，武汉  430074;中国科学院上海光学精密机械研究所强光光学实验室，上海  201800; (2)中国科学院上海光学精密机械研究所强光光学实验室，上海  201800
Published: December 2020

Acceleration of a pre-accelerated electron by an ultra-short and ultra-intense laser pulse in vacuum has been explored. The deceleration by the descending part of the laser pulse can be neglected when the pre-accelerated electron is accelerated by the ascending part of the pulse. Because the acceleration dist ance is much longer than for a initially stationary electron, the energy gain is much larger. The net energy gain can be up to 01GeV with a laser intensity of 1019W/cm2 and an initial electron energy of 45Me V. Final energy ga in of the electron as a function of its initial condition and laser parameters h as also been discussed.
Anomalous thermal expansion of R(Fe, Mo)12 compounds
Authors: Sun Guang-Ai  , Chen Bo  , Du Hong-Lin  ,   (1)北京大学物理系，北京  100871; (2)中国工程物理研究院核物理与化学研究所，绵阳  621900
Published: December 2020

The R(Fe, Mo)12 (R=Nd, Y, Dy) samples have been prepared and measure d by x-ray diffraction at different temperatures. The crystal lattice constant s and degree of the thermal expansion along the different axes are calculated. As a result, we consider that the abnormally thermal expansion of R(Fe, Mo)12 compounds is mainly determined by the Fe-Fe interaction. According to structural parameters of Nd(Fe, Mo)12, the anomaly is caused not on ly by the short Fe-Fe interaction as the previous explanation on other R-Fe inte rmetallic compounds but also by the other strongly positive Fe-Fe interactions. The mechanism of the substitution by Mo affecting the thermal expansion anomal ies is also discussed.
Preliminary structural study of multi-wall carbon nanotubes in a returning phase transition process
Authors: Wang Zhen-Xia  , Wang Sen  , Hu Jian-Gang  , Yu Guo-Jun  ,   中国科学院上海应用物理研究所，上海  201800
Published: December 2020

In this work, amorphous carbon nanowires(ACNWs), formed during ion irradiating m ulti-wall carbon nanotubes (MWCNTs), were annealed at a high temperature of 2400 ℃. Transmission electron microscopy observations revealed that the body of ACNW s had transformed to a tube-like structure similar to that of the original MWCNT s, but the tip structure had various forms and was quite different from the orig inal MWCNTs. Based on the results, we proposed a conceptual model of phase trans ition mechanism.
Effect of single-wall carbon nanotubes’chiral angle for the phonon frequency
Authors: Zhang Hui-Peng  , Jin Qing-Hua  , Wang Yu-Fang  , Li Bao-Hui  , Ding Da-Tong  ,   南开大学物理系，天津  300071
Published: December 2020

The phonon frequencies at the center of Brillouin zone in a series of chiral single-wall carbon nanotubes were calculated numerically, in which the curvature effect was treated appropriately. According to the numerical results, the classification of the vibration modes for chiral tubes at the center of Brillouin zone were analysed. The relations between frequency-chirality and frequency-tube diameter for 12 non-degenerate vibration modes were illustrated.
Effect of the laser power density on the properties and structures of the diamond-like carbon films deposited by pulsed laser ablation of graphite
Authors: Peng Hong-Yan  , Zhou Chuan-Sheng  , Zhao Li-Xin  , Jin Zeng-Sun  , Zhang Bing  , Chen Bao-Ling  , Chen Yu-Qiang  , Li Min-Jun  ,   (1)吉林大学超硬材料国家重点实验室，长春  130012; (2)牡丹江大学，牡丹江  157011; (3)牡丹江师范学院物理系，牡丹江   157011
Published: December 2020

Diamond-like carbon films were deposited by high-frequency and high-power pulse d XeC1 excimer laser ablation of pyrolytic graphite targets in a high vacuum ch amber at room temperature. The effects of the laser power density on the propert ies and structures of the films were studied by setting the laser power density on the target at 108, 109 and 1010W/cm2. The optical transparency and the optical band gap as well as the electron diffraction patterns and Raman spectra of the films were investigated. The results demonstrated that the stru ctures of the films varied from amorphous to nanocrystalline diamond with the l aser power density increasing from 108 to 1010W/cm2.
Structural and optical properties of MgxZn1-xO thin films deposited by radio frequency magnetron sputtering
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(0≤x≤030) have been prepared on sap phire substrates by radio frequency magnetron sputtering at a substrate tempera ture of 80℃. Optical and structural properties of the MgxZn1-x O films were studied using transmittance and x-ray diffraction (XRD)spect ra. XRD patterns indicate that the MgxZn1-xO films have he xagonal wurtzite single-phase structure of ZnO and a preferred orientation with the c-axis perpendicular to the substrates without any significant formation o f a separated MgO phase. The c-axis lattice constant of the MgxZn1-xO films decreases gradually with increasing Mg content. Sharp absorp tion edge appeared in the transmittance spectra of the MgxZn1-x O films, the fundamental band gap of the MgxZn1-xO f ilms were estimated, which increases almost linearly from 3.32 eV at x=0 to 3.9 6 eV at x=030
Studies of quantum confinement effects of excitons in semiconductor crystallites with the B-spline technique
Authors: Hui Ping  ,   广东教育学院物理系，广州  510303
Published: December 2020

The behaviors of the ground-state energies and binding energies of the confined excitons in larger CdTe quantum dots(25—35nm) and the smaller CdS quantum dots(025—35nm) are studied variationally by means of the B-spline technique based on the effective mass approximation method. It is shown from the studie s that:(1) The ground-state energies and binding energies of the confined excito ns in the larger quantum dots are not sensitive to the barrier height of potenti al and the dielectric constant of surrounding material as compared to those of s mall quantum dots; (2) The behaviors of the ground-state energies and binding en ergies of the confined excitons in larger quantum dots are very different with t hose of smaller quantum dots (3)The B-spline technique is a better one to descri be the status of excitons confined by quantum wall or well, and this method is f it to calculate the multi-layer quantum dot accurately.
Opto-thermionic refrigeration of semiconductor heterostructure
Authors: Han Peng  , Jin Kui-Juan  , Zhou Yue-Liang  , Zhou Qing-Li  , Wang Xu  , Zhao Song-Qing  , Ma Zhong-Shui  ,   (1)北京大学物理学院，北京  100871; (2)中国科学院物理研究所,北京凝聚态物理国家实验室，北京  100080
Published: December 2020

Numerical method has been used to analyze the opto-thermionic refrigeration proc ess of semiconductor heterostructure. Based on the drift-diffusion model, curren t continuity equation and Poisson equation are employed to calculate the distrib ution of carriers, the radiative recombination rate and the Auger recombination rate of the semiconductor. In addition, we have calculated the effect of the cha nging of barrier height and the doping density on the refrigeration rate. Thus t he optimum conditions of opto-thermionic refrigeration have been obtained based on these results. This work is of great significance for guiding the experiment research in the future.
Critical temperature of the Gauss system under long-range interactions
Authors: Wang Chun-Yang  , Kong Xiang-Mu  ,   (1)曲阜师范大学物理系，曲阜  273165; (2)曲阜师范大学物理系，曲阜  273165;中国科学院交叉学科理论研究中心，北京  100080
Published: December 2020

Using the Fourier transformation method,we accurately solved the Gauss Model with long-range interactions on the d-dimensional hyper-cubic lattices and the two-dimensional triangular lattices.The long-range interactions we considered here include power exponential decreasing,exponential decreasing and natural logarithmic decreasing.At the same time the critical behavior of the Gauss Model with long-range interactions decaying as r-α on two-dimensional triangular lattices is studied.The critical points of the system under these circumstances are calculated.According to the results we have obtained,we can easily compare the effect of different types of long-range interactions on the critical behavior of the system.As will be seen,for the existence of long-range interactions,the critical temperature of the system rises to some extent.And the effect of the long-range interaction on the critical temperature depends on its decaying rate.
A method of characteristic LIF spectral signatures separation based on radial basis function networks
Authors: Li Hong-Bin  , Liu Wen-Qing  , Zhang Yu-Jun  , Ding Zhi-Qun  , Zhao Nan-Jing  , Wei Qing-Nong  , Wang Yu-Ping  , Yang Li-Shu  ,   中国科学院环境光学与技术重点实验室，中国科学院安徽光学精密机械研究所，合肥  230031
Published: December 2020

The separation of characteristic spectral signatures plays an important role in the laser induced fluorescence (LIF) system used for monitoring dissolved organic matter (DOM) in polluted water,which has advantages of high sensitivity,fast detection,remote measurement,etc. In this paper,a method of characteristic spectral signatures separation based on radial basis function networks (RBFN) will be presented. Using this method,we separated the spectral components of laser,Raman and fluorescence of DOM from the LIF spectral. The concentration of DOM in polluted water can be retrieved from the separated spectrums.
A new class of stable composite soliton in two-dimensional photonic lattice
Authors: Dong Liang-Wei  , Ye Fang-Wei  , Wang Jian-Dong  , Li Yong-Ping  ,   (1)中国科学技术大学物理系，合肥  230026; (2)中国科学技术大学物理系，合肥  230026;中国科学技术大学结构分析开放实验室，合肥  230026
Published: December 2020

We demonstrate that a new class of stable composite soliton exists in a two-dimensional lattice. It can be produced by the evolution of a stationary solution of nonlinear Schrdinger equation with a periodic potential modulation. We emphasize that this new kind of composite soliton is different from the dipole soliton reported before though they seem alike. The components of the soliton exchange energy during the propagations and the total energy of soliton conserves.
A new Tortoise coordinate transformation and entropy of arbitrarily accelerating charged black hole
Authors: Niu Zhen-Feng  , Liu Wen-Biao  ,   (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;河北北方学院物理系，张家口  075000
Published: December 2020

Considering the Klein_Gordon equation near the event horizon, Hawking temperature is calculated under a new Tortoise coordinate transformation. In the meantime , the cut-off parameter in thin membrane model is also simplified to the same as that in the static and stationary cases.
Improved tanh-function method and the exact solutions for the hybrid-lattice and Ablowitz-Ladik-lattice
Authors: Zhu Jia-Min  , Ma Zheng-Yi  , Zheng Chun-Long  ,   (1)丽水学院物理系，丽水  323000; (2)丽水学院物理系，丽水  323000;上海大学应用数学与力学研究所，上海  200072
Published: December 2020

In this paper, by using the improved tanhmethod, the hybridlattice system an d Ablowitzladiklattice system are reduced to nonlinear algebraic equations, and then the new exact solutions for these equations, which include exact soliton wave solutions and periodic solutions, are obtained through solving these nonlinear algebraic equations.
Controlling chaotic dynamical behavior of a semiconductor laser with external optical feedback using sliding mode variable structure control scheme
Authors: Huang Liang-Yu  , Luo Xiao-Shu  , Fang Jin-Qing  , Zhao Yi-Bo  , Tang Guo-Ning  ,   (1)广西师范大学物理与信息工程学院,桂林  541004; (2)中国原子能科学研究院,北京  102413
Published: December 2020

In this paper, a semiconductor laser with external optical feedback is entered into chaotic motion by increasing the time of the external optical feedback at first. And then, the sliding mode variable structure control scheme is used to control the chaotic motion of this laser system. The advantage of this method is that the stable output laser can be obtained in a short time and the output power strength of the laser can be adjusted flexibly in accordance with the engineering requirement. Theory analysis and simulation results show that the results of the control have powerful stability and robust .Our research results have many helpful values to improve the speed of stable output, flexible adjustment of laser output power as well as efficiency of energy transformation for real laser system.