bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of atomic fluctuation on the localized modes in one-dimensional system
Authors: Zhang Da-Cheng  , Wang Lu-Xia  , Liu De-Sheng  , Han Sheng-Hao  , Xie Shi-Jie  ,   山东大学物理与微电子学院,晶体材料国家重点实验室,济南  250100
Published: December 2020

In the frame work of the tight-binding approximation, the effect of defects and disorder on the vibrational modes in one-dimensional systems was studied through a random distribution model. It was found that the Goldstone mode of a so liton or polaron is pinned and its frequency is shifted up to a finite value. Th e weak mode g4 of a soliton is enhanced. The staggered modes keep the ir localization even if there is a large lattice fluctuation. Some new modes appear when the perfect soliton or polaron configuration is disturbed.
The homotopic solving method of sea-air oscillator for ENSO model
Authors: Mo Jia-Qi  , Lin Wan-Tao  , Zhu Jiang  ,   (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
Published: December 2020

A delayed oscillator of El NiňoSouthern Oscillation (ENSO) models are conside red. Using the method of homotopic mapping, the approximation of the solution for ENSO models is obtained.
Localized fractal structure of the (2+1)-dimensional Broer-Kaup equations
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

The linearized form of (2+1)dimensional Broer-Kaup equations is established b y using the improved homogeneous balance method. Starting from the B?cklund tra nsformation, a variableseparation solution with the entrance of some arbitrary function is obtained. By using Jacobian elliptic functions, new fractal structu res are obtained.
Expansion method for modified Jacobi elliptic function and its application
Authors: Shi Yu-Ren  , Guo Peng  , Lü Ke-Pu  , Duan Wen-Shan  ,   西北师范大学物理与电子工程学院,兰州 730070
Published: December 2020

We generalized the Jacobi elliptic function expansion method and obtained some new exact periodic solutions, thus replenished the known results of a number of nonlinear wave equations by using this method.
Dependences of isospin fractionation degree on the mass and beam energy of a colliding system
Authors: Guo Wen-Jun  , Liu Jian-Ye  , Xing Yong-Zhong  ,   (1)兰州重离子加速器国家实验室原子核理论中心,兰州 730000;天水师范学院近代物理理论研究所,天水 741000; (2)兰州重离子加速器国家实验室原子核理论中心,兰州 730000;中国科学院近代物理研究所,兰州 730000; (3)兰州重离子加速器国家实验室原子核理论中心,兰州 730000;中国科学院近代物理研究所,兰州 730000;天水师范学院近代物理理论研究所,天水 741000
Published: December 2020

Based on the isospindependent quantum molecular dynamics model, we have invest igated the dependences of isospin fractionation degree (N/Z)n/(N/Z)fragon the mass and the beam energy of colliding system. The (N/Z)n a nd (N/Z)frag are the neutron proton ratio of the nucleon emission (gas-phase) and that of the fragment emission (liquid phase) respectively. The isosp in fractionation degree is a sensitive func tion to the mass and beam energy of the colliding system. The (N/Z)n/(N/Z)frag reduces with increasing mass of the colliding system when the beam energy and n eutron proton ratio of the colliding system are fixed. This is due to the larg er compr ession, small heating energy and larger critical temperature of the gasliquid phase transition for the heavy colliding system, compared to those of the light colliding system. We also found that (N/Z)n/(N/Z)frag enhances wit h increasing beam energy due to the increase of excitation energy of the collidi ng system which leads to larger nucleon transport and isospin fractionation. But the isospin frac tionation only occurr in the energy region for producing the liquidgas phase t r ansition. In this case, we propose that (N/Z)n/(N/Z)frag can be directly compa red with the experimental data to get the information about symmetry potential.
A new pulse neutron detector used in the mixture radiation fields of neutron and gamma rays
Authors: Yang Hong-Qiong  , Zhu Xue-Bin  , Yang Gao-Zhao  , Li Lin-Bo Song  , Xian-Cai  ,   (1)中国工程物理研究院电子工程研究所,绵阳 621900; (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 new type of pulse neutron detector consists of two PIN detectors. The respon se for the rays was studied with the pulse gamma sources. The neutron respons e was studied using the DT neutron sources and compared with the scintillator de tector. Results show that the detector is insensitive to gamma radiation, and th e neutron sensitivity was determined by the neutron radiator. It is a new pulse neutron detector in the neutron and gamma mixed radiation fields.
Theoretical predictions on the low-lying excitation structure of super-heavy element bohrium (Z=107)
Authors: Ding Xiao-Bin  , Dong Chen-Zhong  ,   (1)西北师范大学物理与电子工程学院,兰州 730070; (2)西北师范大学物理与电子工程学院,兰州 730070;兰州重离子加速器国家实验室原子核理论中心,兰州 730000
Published: December 2020

The success of theoretical and experimental study of fermium (Z=100) enlightened us to perform further investigation of heavy elements. We studied so me lowlying absorption spectroscopy and the resonant absorption probability of bohrium (Z=107) by using MCDF method which included the correlation effects and relativistic effects systematically. We hope our results will be useful for the further experiments.
Atomic and ionic light emission spectra of dipole transition and forbidden transition induced by the impact of 126Xe30+ on Ni solid surface
Authors: Zhang Xiao-An  , Zhao Yong-Tao  , Li Fu-Li  , Yang Zhi-Hu  , Xiao Guo-Qing  , Zhan Wen-Long  ,   (1)西安交通大学应用物理系,西安 710049; (2)西安交通大学应用物理系,西安 710049;中国科学院近代物理研究所,兰州 730000; (3)中国科学院近代物理研究所,兰州 730000
Published: December 2020

The measurement of light spectrum of NiⅠand NiⅡwith wavelengths from 200 to 1 000nm emitted from the solid surface of Ni, which is excited by slow highly char ged ions 126Xe30+，is reported. The result shows that the chara cteristic spectral lines from transitions between complex configurations of atom s and ions can be effectively excited by the impact of highly charged ions on a solid surface even though the ionic beam is very weak. The result shows especia lly that the characteristic spectral lines from forbidden transition (M1and E2) of NiⅠand NiⅡcan be effectively excited.
Dissociation of the HCN molecule in the highly excited vibrational states
Authors: Zheng Dun-Sheng  , Guo Xi-Kun  ,   汕头大学理学院,汕头 515063
Published: December 2020

The bond breaking at high excitation of the HCN molecule with various couplings is studied along with Morse oscillator by the coset (phase) space method of Lie algebra. It is demonstrated that the couplings of higher orders, are prone to bo nd dissociation. We also note that couplings reduce the dissociation energy.
The defect effect in the two-dimensional negative permeability material
Authors: Kang Lei  , Zhao Qian  , Zhao Xiao-Peng  ,   西北工业大学电流变技术研究所,应用物理系,西安\ 710072
Published: December 2020

The defect effect in the two_dimensional (2D) negative permeability material, co nsisting of copper hexagon split ring resonators (SRRs), is investigated. The pr inted circuit boards with SRRs on one side are fabricated using a shadow mask/et ching technique. We use a rectangular waveguide system to measure the X_band tra nsmission in 2D negative permeability materials with different dot and line defe cts. The measured data shows that there is only one resonance frequency and high quality factor \%Q\% for a 2D negative permeability material without defects. T he main resonance frequency has a shift and the resonant peak value decreases wh en the defect SRRs are introduced into the samples. We consider that the defect SRRs break the periodic structure of the samples, which results in the shift of the main resonance frequency and the resonant intensity. The investigation of th e defect effects is important not only for the understanding of the characterisf ics of the negative permeability material, but also for the realization of the l eft_handed metamaterials in the infrared and visible region.
Plasma sheath in a magnetic field
Authors: Zou Xiu  , Liu Jin-Yuan  , Wang Zheng-Xiong  , Gong Ye  , Liu Yue  , Wang Xiao-Gang  ,   大连理工大学三束材料改性国家重点实验室，大连 116023
Published: December 2020

The structure of the plasma sheath in an oblique magnetic field was investigated with the fluid method. In various different magnitude and directions of the ma g netic field, the electron and ion density distribution, ion flow velocity, elect ron potential and Bohm's criterion have been calculated. It is shown that the magnetic field has obvious effect on the plasma sheath. Under the action of electrostatic and Lorentz forces, the ion flow makes a helical movement, and the ion densi ty distribution fluctuates.
Implosion compression characteristic of direct-driven ablation target with 1.06μm laser
Authors: Cheng Jin-Xiu  , Zheng Zhi-Jian  , Chen Hong-Su  , Miao Wen-Yong  , Chen Bo  , Wang Yao-Mei  , Hu Xin  ,   中国工程物理研究院激光聚变研究中心，高温高密度等离子体物理实验室，绵阳 621900
Published: December 2020

This paper describes the diagnostic techniques and experimental methods used for investigating the properties of implosion compression in direct drive . Several diagnostic techniques with fine time, space and spectrum resolution are employed to obtain the information concerning implosion, such as radiation un iformity on the capsule, compression symmetry, volume compression ratio, implosi on time, implosion velocity and average electron temperature of the capsule shell. Some of the typical results measured in the experiments are presented and as imple discussion is also given.
Discrete-continuous spectral transition in single wall toroidal carbon nanotubes
Authors: Liu Chao-Ping  , Ding Jian-Wen  , Yan Xiao-Hong  ,   湘潭大学物理系，湘潭 411105
Published: December 2020

Taken into account the curvature effects，we build a singleπ orbital tight-bi ndi ng model for armchair toroidal carbon nanotubes, from which the interaction matr i x elements have been derived by means of the wavefunction decomposition method. The electronic structures of armchair toroidal carbon nanotubes are studied, whi ch are dependent on both the torus radius and the tube radius. The energy spectr al transition is observed from the discrete to continuous ones, as the t orus radius and the tube radius are varied.
Modeling of dendritic growth by means of cellular automaton method
Authors: Li Qiang  , Li Dian-Zhong  , Qian Bai-Nian  ,   中国科学院金属研究所，沈阳 110016
Published: December 2020

In order to reflect the characteristic of sharp interface during the d endritic growth process, cellular automaton method is used to simulate the dendr ite evolution. In this method the different physical properties in both solid an d liquid phases are adopted to reflect the different heat_transfer rate. The simulated results show that there is solute micro-segregation between the two p rimary dendritic arms. In addition，the solute concentration gradient and temper ature ahead of the solid/liquid interface decrease gradually with increasing solidification time. Comparing the simulated radius of the dendritic tip with the theore tical radius, we obtain that the simulated results fit the theoretical radius well, and the deviation is less than 1μm.
Electronic structure of the stable GaAs(2 5 1 1) surface
Authors: Jia Yu  , Yang Shi-E  , Ma Bing-Xian  , Li Xin-Jian  , Hu Xing  ,   郑州大学物理工程学院，郑州大学材料物理教育部重点实验室，郑州 450052
Published: December 2020

We have studied the optical properties of the interface of Al and GaAs surface q uant um well by insitu photoreflectance (PR) spectroscopy in a molecular beam e pitax y (MBE) system. The intermixing of Al and GaAs surface quantum wells forms an AlxGa1-xAs barrier layer on GaAs, which would shift the inte r_band transition peaks of the GaAs quantum well. Based on the calculation using effective mass approximate method, we fi nd that the intermixing length is 0.5nm, which is an important parameter in sem iconductor technology.
Fabrication of Tl-2212 superconducting thin films by a two-step procedure with post-annealing in a closed container
Authors: Yi Chang-Hong  , Hu Fang-Ren  , Zhang Qing-Gang  , Chen Ying-Fei  , Xu Xiao-Ping  , Zheng Dong-Ning  ,   (1)山东师范大学物理与电子学院，济南 250014; (2)中国科学院物理研究所超导国家重点实验室，北京\ 100080; (3)中国科学院物理研究所超导国家重点实验室，北京\ 100080;山东师范大学物理与电子学院，济南 250014
Published: December 2020

Highquality Tl2Ba2CaCu2Oy(Tl2212) thin films were prepared on s ingle crystal(001) lanthanum aluminate (LaAlO3) substrates by a twostep method. Tlfree amor phous precursor films were first deposited by a pulsed laser deposition techniqu e and then the thalliation, crystallization and oriented growth of the films wer e obtained in the process of annealing treatment in a sealed high-temperature st eel capsule at temperature of 720—850℃ . Xray diffraction reflections reveal th e existence of only Tl2212 phase with nearly perfect caxis orientation. The fu ll width at half maximum of ω scan of (0012) peak was 072°. Scanning electro n m icrographs of the thin films show that the surfaces of the films are smooth. The zeroresistance transition temperature TC0 is 1062K.
A method for designing high-order planar superconducting quantum interference device gradiometer
Authors: Lang Pei-Lin  , Chen Ke  , Zheng Dong-Ning  , Zhang Ming-Jian  , Qi Han-Hong  , Zhao Zhong-Xian  ,   (1)中国科学院物理研究所超导实验室，北京 100080; (2)中国科学院物理研究所超导实验室，北京 100080;燕山大学材料科学与工程学院，秦皇岛 066004
Published: December 2020

We have proposed a novel method for designing the second_order planar gradiomete rs and even high_order gradiometers.The gradiometer consists of two parts,one is the superconducting quantum interference device(SQUID),the other is the pickup loop which is directly coupled with the SQUID.The pickup loop consists of two p arallel_connected loops,each loop consists of several opening loops which are co nnected with minimal channels between them.By adjusting the site,size and shape of these opening loops,we can realize that the current in the common line betwee n the two loops is proportioned by the high_order gradient of the magnetic field .Because the line is coupled with SQUID,so we can measure the high_order gradien t of the magnetic field.We have got the relations between the site and the size of loops by calculation, and prove it can work.For high_order gradiometers,the baseline is important.Our design can use flip_chip configration to lengthen the baseline.Another method to get longer baseline is to design two_dimensional gradiometers which are easy to design using our method.
Charge storage and its dynamics in positively corona charged polytetrafluoroethylene film electrets
Authors: Zhang Peng-Feng  , Xia Zhong-Fu  , An Zhen-Lian  , Wu Xian-Yong  ,   同济大学波耳固体物理研究所,上海 200092
Published: December 2020

In this paper, charge storage and its dynamics in positively corona char ged polytetrafluoroethylene（PTFE） film electrets have been studied. It is foun d that from room temperature to 100℃ and from about 150℃, especially from 180 ℃ to higher temperatures, slow retrapping controls the transport of detrapped c h arge; however, from about 100℃ to 150℃ the fast retrapping plays a dominant ro le. The increase of the initial surface potential will lead to a significant decay of charge density, so by means of properly controlling the charging parameter an d the heat treatment process we can get positively and negatively charged PTFE f ilm electrets with the same charge density, which not only have a similar charge storage life but also an outstanding charge storage stability. 
One-dimensional magneto optical multi-layer film isolator with multi-defect
Authors: Wen Xiao-Wen  , Li Guo-Jun  , Qiu Gao-Xin  , Li Yong-Ping  , Ding Lei  , Sui Zhan  ,   (1)中国工程物理研究院第八研究所，绵阳 621900; (2)中国科学技术大学物理系，合肥 230026
Published: December 2020

Because of the localization of light, the magneto_optical (MO) photonic crystal, composed of magnetic and dielectric films periodically or quasi_periodically, can be used to manufacture the MO isolator. A transfer matrix method, suitable for computing the propagation of polarized l ight in anisotropic media, is described in detail in this paper. Using this met hod, we discuss the MO properties of a new type of MO isolator with multi_defect , and find that the spectra are broadened with increasing number of defects. A reflection_mode MO isolator without extra reflected layers is proposed when th e number of defects is large enough.
The influence of pulse width on transient thermally induced optical nonlinearities in a Kerr nonlinear medium
Authors: Chen Shu-Qi  , Liu Zhi-Bo  , Zhou Wen-Yuan  , Tian Jian-Guo Zang Wei-Ping  , Zang Wei-Ping  , Song Feng  , Zhang Chun-Ping  ,   南开大学物理科学学院光子学中心, 天津 300071
Published: December 2020

We report the experimental results on the effect of pulse width on transient thermally induced optical nonlinearities in the nanosecond r egime. We have obtained the Z_scan curves of the CS2 solutions of nigrosin e for different pulse widths, and analyzed the co_existence of third_order and transie n t thermally induced optical nonlinearities. The process of changing from transi ent state to steady_state thermal_induced optical nonlinearities was observed. M eanwhile, we have obtained the results of numerical simulation by solving simult aneously acoustic and electromagnetic wave equations, which agree well with the experimental results.
Effect of Mg doping on properties of AlGaN films
Authors: Feng Qian  , Wang Feng-Xiang  , Hao Yue  ,   (1)西安电子科技大学技术物理学院,西安 710071; (2)西安电子科技大学技术物理学院,西安 710071;西安电子科技大学微电子研究所,西安 710071
Published: December 2020

Effect of Mg doping on the properties of AlGaN layers gro wn on sapphire substrates by metal_organic chemical vapor deposition were studie d using x_ray diffraction and Raman scattering. When the doping of Mg was low, the E2 mode shifted to lower frequency and the full width half at maximum of the rocking curve and A1(LO) mode decreased. However, as the flow rate of CP2Mg increased ti ll the AlGaN was doped with a dose as high as 4×102/sup>cm-3, the quali ty of film de creased gradually and the E2mode shifted to higher frequency, indicat ing a compressive stress in the films. Finally, the relation between the Raman s hift and the stress alteration was described by Δσ＝-0298+0562ΔE.
Spectroscopic properties of Tm3+-doped NaY (WO4)2 crystals
Authors: Song Feng  , Su Jing  , Tan Hao  , Shang Mei-Ru  , Wu Zhao-Hui  , Tian Jian-Guo  , Zhang Guang-Yin  , Cheng Zhen-Xiang  , Chen Huan-Chu  ,   (1)南开大学光子学中心,天津\ 300071; (2)山东大学晶体研究所,济南\ 250100
Published: December 2020

Z_scan experiments are performed on the azobenzene polymer (DR_13_PMMA) films with He_Ne laser. It is found that the relation between the cha nge of refractive index of the sample and the light intensity behaves like a sat u rable effect, whose relative parameters are alterable with light intensity. It i s also found that the change of refractive index induced by linearly polarized l ight is distinctly greater than that induced by circularly polarized light. The phenomena are explained by using the theory based on the effect of angular hole burning of photoisomerization.
p-n GaInP2/GaAs tandem solar cells*
Authors: Chen Ming-Bo  , Cui Rong-Qiang  , Wang Liang-Xing  , Zhang Zhong-Wei  , Lu Jian-Feng  , Chi Wei-Ying  ,   (1)上海交通大学物理系,上海　200030; (2)上海交通大学物理系,上海　200030;上海空间电源研究所,上海　200233; (3)上海空间电源研究所,上海　200233
Published: December 2020

This paper reports the study on p-n GaInP2/GaAs tandem cells. The cell samples were produced by metal-organic chemical vapor deposition at a low gas pressure. In order to optimize the device configuration, numerical modeling has been performed for the impacts of a fieldaided collection on the performances of the top cells. On the basis of modeling results, a modified configuration of top cells is introduced, using p+-p—n—n+ structure instead of p+n structure. This modification has brought about much improved photovoltaic performance of the top and tandem cells, with the conversion efficiency Eff=14.26% and 23.82% (AMO, 25℃, 2×2cm2), respectively.
A new type of conserved quantities for Birkhoffian systems*
Authors: Zhang Yi  , Fan Cun-Xin  , Ge Wei-Kuan  ,   (1)湖州师范学院物理系,湖州　313000; (2)苏州科技学院土木工程系,苏州　215011
Published: December 2020

This paper gives a new type of conserved quantities for Birkhoffian systems. First, the equations of motion of the systems are established, and the definitions and criterions of Mei symmetries are given. Next, an existence theorem for the n ew type of conserved quantities of the systems is given, and the generalized Killing equations used to determine the infinitesimal generators are deduced. Finally, the inverse theorem of the conservation law is established.
Exact quantum solution for the general time-dependent linear potential and related problems
Authors: Liang Mai-Lin  , Sun Yu-Jing  ,   (1)天津大学理学院物理系,天津　300072; (2)天津大学理学院物理系,天津　300072；南开大学天津大学刘徽应用数学中心,天津　300071
Published: December 2020

For the general time-dependent linear potential, the exact and complete solution of the Schr?dinger equation was obtained by assuming a form of wave function. Meanwhile, it was pointed out that the matrices φ(t)〉和ψ(t)〉 defined by the two wave functions 〈φ(t)xψ(t)〉和〈φ(t)pψ(t)〉 satisfy classical equations of motion. According to the ensemble theory of quantum mechanics, such classical equations describe the motion of fluid. A further research shows that similar conclusions apply to any linear system.
The uncertainty relations and squeezing effects for mixed states*
Authors: Deng Wen-Ji  , Liu Ping  , Xu Xiao  ,   (1)华南理工大学材料科学研究所,广州　510640; (2)华南理工大学物理系,广州　510640
Published: December 2020

Based upon the Heisenberger's uncertainty relations for mixed states, the minimu muncertainty and squeezing effects are studies. Although all minimum uncertainty states must be pure states, the nucertainty of one dynamical variable can be squeezed in some pure states or mixed states, even if they are not minimum uncert ainty states for the pair of dynamical variables. In addition, we present the ge neral uncertainty relation of statistics, which has the similar mathmatical stru cture of Heisenberg's indeterminacy principle, but has no relation with quantum interfernce.
Statistical entropy of Barriola-Vilenkin black hole
Authors: Li Gu-Qiang  ,   湛江师范学院信息科技学院,湛江　524048
Published: December 2020

The partition functions of bosonic and fermionic field in Barriola-Vilenkin blac k hole are directly derived by using the method of quantum statistics. Then the entropy of the Barriola-Vilenkin black hole is calculated by using the improved brick-wall method in the frame of membrane model.
Nonlinear dynamics and control of symmetric chaotic systems*
Authors: Yu Jin-Jiang  , Zhang Ming-Xuan  , Xu Hai-Bo  ,   (1)北京应用物理与计算数学研究所，北京  100088; (2)石家庄师范专科学校物理系，石家庄  050801; (3)石家庄师范专科学校物理系，石家庄  050801;北京应用物理与计算数学研究所，北京  100088
Published: December 2020

Based on the continuous feedback control idea,a novel nonlinear dynamics of map and control method for a symmetric chaotic system is presented.Different from t he periodical orbit method,the basis to choose controlling parameters has been g iven.Only by appropriately adjusting feedback parameters,any periodical orbit can be reached.This method is applied to Logistic map,and good results have been o btained.
Simulation and analysis of 6H-SiC pn junction ultraviolet photodetector
Authors: Zhou Yong-Hua  , Zhang Yi-Men  , Zhang Yu-Ming  , Meng Xiang-Zhi  ,   西安电子科技大学微电子研究所，西安  710071
Published: December 2020

The spectral responsibility of 6H-SiC pn junction ultraviolet photode tector has been simulated by 2D numerical model. The effect of different impurity concentration and different junction-depth on the responsibility is discussed in this paper. For p+n device, the responsibility can be as high as 167.2 mA/ W when the width of p+ layer is about 0.2μm, and the impurity concentrations are about 9×10.18cm-3and 1×10.6 cm-3 in p+layer and nlayer, re spectively. For n+p device, the responsibility is as high as 183.5 mA/W when the width of n+-layer is about 0.2μm, and the impurity concentrations are abo ut 9× 10.18cm-3 and 1×10.6cm-3in n+-layer and p-layer, respe ctively. It is shown that the result of simulation agrees with the experimental data very well.
Entanglement swapping in the process of two-level atoms interacting with cavity fields of coherent states*
Authors: Lai Zhen-Jiang  , Yang Zhi-Yong  , Bai Jin-Tao  , Sun Zhong-Yu  ,   (1)河南师范大学物理系,新乡  453007;西北大学光子学与光子技术研究所,光电子技术省级重点实验室，西安  710069; (2)西安交通大学电子与信息工程学院,西安  710049; (3)西北大学光子学与光子技术研究所,光电子技术省级重点实验室，西安  710069
Published: December 2020

From the viewpoint of quantum information theory, a multiatom and muticavity system was investigated. In the system the interaction between the atoms and the fi elds in the cavities is described by the intensity-dependent coupling Jaynes-Cummings model. It is found that the atomic maximal entangled state can be transformed into the maximal odd-even-like coherent entangled state, whereas the maximal odd-even-like coherent entangled state also can be transfor med into the atomic maximal entangled state.
Cavity field spectra of two different atoms interacting with a Two-mode field through Raman process
Authors: Zhang Gui-Ming  , Li Yue-Ke  , Gao Yun-Feng  ,   聊城大学教育传播技术学院,聊城  252059
Published: December 2020

The cavity field spectra of two different atoms interacting with two-mode field s through Raman process are studied.The effects of relative coupling constant R=g2/g1 on the spectrum structure are discussed.It is found thatR pla ys a different role in the syectrum for vacuum,weak or strong initial field.Dege nerate spectrum structure appears usually forR=1 orR=0.A complicated a symmetric multipeak structure appears when R is between 0 and 1.When the f ield of upper frequency mode is vacuum,its spectrum is influenced sensitively by the field intensity of the other mode for fixed R.
Influence of the potential in n-type DBR on threshold in vertical-cavity surface-emitting lasers
Authors: Zhao Hong-Dong  , Song Dian-You  , Zhang Zhi-Feng  , Sun Ji ng  , Sun Mei  , Wu Yi  , Wen Xing-Rao  ,   (1)河北工业大学信息工程学院，天津  300130; (2)河北省广播电信局，石家庄  050041
Published: December 2020

In this paper, a simulation software with a direct coupling in quasi-three-di mensions for the gain-waveguide vertical-cavity surface-emitting lasers has b een realized. The electrical field, carrier density, optical-field and temperature distributions in the vertical-cavity surface-emitting lasers are given. The proper threshold characteristics are shown only when the potentia ls in the p-type and n-type DBR layers are studied together.
Influence of external electric field on photorefractive two-wave coupling in SBN:Cr crystal and its applications
Authors: Zhao Jian-Lin  , Li Zhen-Wei  , Yang De-Xing  , Ma Yang-Hua  , Yang Dong-Sheng  ,   西北工业大学应用物理系，西安  710072
Published: December 2020

The properties and applications of the photorefractive two-wave coupling in con gruent SBN:Cr(Sr0.61Ba0.39Nb2O.6:Cr)crystal under external dc e lectric field are experimentally investigated in this paper.The variation of the intensity gain coefficient of the two-wave coupling with the external field is analyzed,and the measurement results are presented.It is found that the photore fractive two-wave coupling gain and response rapidity can be both increased,by applying appropriate external electric field to the crystal.Further study indica tes this electric response property of SBN:Cr crystal is useful to some applicat ions,such as improving the image edge-enhancement and the image edge-enhanceme nt joint-transform correlator based on the nonlinear energy transfer of photore fractive two-wave coupling in the crystal.
Numerical study on damage phenomenon induced by transverse stimulated Brillouin scattering
Authors: Guo Shao-Feng  , Lu Qi-Sheng  , Zhou Ping  , Zeng Xue-Wen  , Deng Shao-Yong  , Cheng Xiang-Ai  ,   国防科学技术大学理学院，长沙  410073
Published: December 2020

Based on the coupled wave equations of nonlinear optics, a two-dimensional p hysics model is established to describe transverse stimulated Brilluoin satteri ng (TSBS) in large-aperture optics of a high-power laser system. The temporal and spatial profile of the stress induced by TSBS is evaluated numerically, and the damage characteristics of optical components is presented, which agrees well with the experimental phenomenon observed at LLN laboratory. The energy loss induced by TSBS are calculated to be up to 20%, sho wing that TSBS may have strong influence on routine operation of high-power las er systems.
Diffusion theory of spin injection into organic polymers*
Authors: Ren Jun-Feng  , Fu Ji-Yong  , Liu De-Sheng  , Xie Shi-Jie  ,   山东大学物理与微电子学院，晶体材料国家重点实验室，济南　250100
Published: December 2020

Based on the theory of electrical spin injection into semiconductors, by conside ring the car riers of spin polarons and spinless bipolarons in organic polymers, we suggested a model of spin injection into organic polymers. It was found that a high curre nt polarization can be obtained by adjusting the spin current polarization in the ferromagnetic layer or the conductivities of the ferromagnetic and organic layers. Effect of the proportion of polarons to carriers on the spin current polarization was discussed.
Phase separation in La2NiO4+δ studied by lowfrequency internal friction technique
Authors: Zhang Hua-Li  , Liu Wei  , Li Dong-Cai  , Wu Xiu-Sheng  , Chen Chu-Sheng  ,   中国科学技术大学材料科学与工程系，合肥　230026
Published: December 2020

There exists a low-frequency relaxation internal friction peak in La2NiO4+δwithδ=0.071, 0.110, 0.135 and 0.140, the peak position shifting to higher temperatu re, when more excess oxygen is incorporated. At δ=0.087 two peaks were obse rved which may be attributed to the jump of the interstitial oxygen atoms in the diff erent kind of the one-dimensional ordering phase formed by phase separation. At δ=0.038 two peaks were also observed which may be attributed to the jump of the i nterstitial oxygen atoms in the low-temperature tetragonal phase and the one-dimensional ordering phase formed by phase separation.
Glass transition kinetic property of novel bulk Zr-Al-Ni-Cu (Nb,Ti) amorphous alloy*
Authors: Chen Zhi-Hao  , Liu Lan-Jun  , Zhang Bo  , Xi Yun  , Wang Qiang  , Zu Fang-Qiu  ,   合肥工业大学材料科学与工程学院，合肥　230009
Published: December 2020

The kinetic property during the glass transition process of Zr_Al_Ni_Cu (Nb,Ti) amorphous alloys was systematically investigated by differential scanning calorimetry method. The activation energy (ΔE) at the glass transition temperature was much smaller than tradition amorphous alloys and have different magnitude compared to ΔEvalue at Tx. These reveal that the bulk amorphous alloys show special structure characteristics and that is the reason of its big glass_forming ability. The Vogel_Fulcher_Tammann fits to the experimenta l data are given by the full curves and the fragility parameter mvalue was calculated to be about 30, reflecting its “strong" liquid property in deep_unde rcooled region. The B value of Lasocka function，atom activation energy and glass fragility parameter reveal a close relationship between kinetic behavior at glass transition and the glass_forming ability. So it could be used as an impor tant judgment for glass_forming ability.
Anomalous thermal conductivity in Nd＿1.67Sr0.33NiO＿4
Authors: Gao Hui-Ping  , Li Bo  , Yu Yong  , Ruan Ke-Qing  , Wu Bai-Mei  ,   中国科学技术大学结构分析开放实验室，物理系，合肥　230026
Published: December 2020

The temperature dependence of thermal conductivity (K),resistivity (ρ) and low field ac susceptibility (χ) of perovskite nick elates Nd＿2-xSr＿xNiO＿4(x =0.33,1.35) have been measured at temperatures from 77 to 300 K. The thermal conductivity an omalies associated with charge_order (CO) and spin_order (SO) are observed simultaneously in Nd＿1.67Sr0.33NiO＿4 for the firs t time so far as we know. The thermal conductivity is enhanced belowT_CO , but is suppressed near T＿SO. There is also response to CO and S O in the χ-Τ curve. Only CO is observed in the ρ-Τ curve. In contrast, th ere are no anomalies in K-Τ, ρ-Τ andχ-Τ of Nd＿1.67Sr0.33NiO＿4. The anomalous phonon thermal conductivi ty in Nd＿1.67Sr0.33NiO＿4 indicates that there are strong charg e_phonon interaction and the spin_phonon interaction in this compound.
The variable metric algorithm for ground state energy of ionized-donor-bound excitons in semiconductors
Authors: Yan Hai-Qing  , Tang Chen  , Zhang Hao  , Liu Ming  , Zhang Gui-Min  ,   天津大学应用物理系，天津　300072
Published: December 2020

We present an optimization method, called the variable metric algorithm, to calc ulate the ground-state energies of excitons. The ground-state energ ies of two-dimensional ionized-donor-bound excitons(D＾+,X)have been calcu lated variationally for all values of effective electron-to-hole mass ratioб. They are compared with those obtained by the variational method. The results show that the proposed method is simple in software programming, acc urate, and has more advantages than the traditional variational method for the g round-state energies. The method is especially fitted for complex systems.
Microfabrication of magnetic tunnel junctions on 4-inch Si/SiO＿2 substrate*
Authors: Wang Tian-Xing  , Wei Hong-Xiang  , Li Fei-Fei  , Zhang Ai-Guo  , Zeng Zh ong-Ming  , Zhan Wen-Shan  , Han Xiu-Feng  ,   中国科学院物理研究所与凝聚态物理中心磁学国家重点实验室, 北京　100080
Published: December 2020

Magnetic tunnel junctions (MTJs) with different sizes from 5μm×5μm to 15μm×60μm were fabricated on 4_inch Si/SiO_2 substrates. Their mag netoelectronic properties were investigated using the four_probe measuring system. The typical values of junction resistance_area product and tunneling mag netoresistance (TMR) ratio of the MTJs are 16 kΩμm^2and 18% respectively. The absolut eerrors of junction resistance_area product and TMR ratio are within 10% and 7% respectively for all the MTJs. All of the MTJs fabricated and measured show a good uniformity. Our experimental results show that such MTJs can be used to fabrica te the prototype demonstration devices for magnetoresistive random access memory .
Thickness and strain effects on electronic transport and Curie temperature in La_0.67Ca0.33MnO_3 films
Authors: Xiong Chang-Min  , Sun Ji-Rong  , Wang Deng-Jing  , Shen Bao-Gen  ,   中国科学院物理研究所与凝聚态物理中心磁学国家重点实验室，北京　100080
Published: December 2020

La_0.67Ca_0.33Mn_O.3 films with thickness between 25 and 400nm were fabricated on (001)SrTiO_3 and (001)LaAlO_3 substrates, using pulsed laser deposition. The magnetization and resistivity ρ of the fil ms were studied as functions of thickness. The reduction of t causes the decrease of the Curie temperature T_C in addition to the increase of ρ of the films. Com pared with the compressive strain in the La_0.67Ca_0.33Mn_O.3/La AlO_3 films, the tensile strain in the La_0.67Ca_0.33Mn_O.3/SrTiO_3 films causes a faster reduction of T_C with t, and a larger value of ρ_０. The low_temperature ρ is found to follow well ρ=ρ_0+Bω_s/sin h^2(ω_s/2/k_BT)+CT^n， with ρ_０ being the residual resistivity. The second term arises fro m the scattering by a soft optical phonon mode, and the third term denotes the other possible transp ort mechanisms. B, ω_s(the frequency of a soft optical mode) and C are fitting parameters. At temperatures higher than T_C, ρ of all the films show activated conduction with ρ=DT×exp（E_a/k_BT）. Here, E_a is the activation energy. Based on the investigation of ρ_０, ω_s and E_a, the thickness and strain effect s in the films are discussed, separately. Further study shows that the variation of T_C is mai nly associated with E_a and ω_s, confirming the crucial role of the electron_phonon coupling in the strain effects on T_C.
Large scale synthesis of single-walled carbon nanotubes by an arc-discharge method at controlled temperatures
Authors: Zhao Ting-Kai  , Liu Yong-Ning  ,   西安交通大学金属材料强度国家重点实验室，西安　710049
Published: December 2020

Large amounts of single-wall carbon nanotubes(SWNTs) deposited on all the wall of the chamber have been obtained in helium and nitrogen mixed atmosphere using Co-Ni alloy catalyst with a modified arc furnace which can control the temperature during arcing process. Additionally, there are many weblike deposition products located between the cathode and anode. By twostep purification:the as-grown SWNT was heated in air at 500℃ for 30min, then soaked in 37% hydrochloric acid for 72h and filtered with deionized water. Microanalysis was carried out by Transmission electron microscopy(TEM), high-resolution TEM and Raman spectroscopy. The results obtained indicate that the purified SWNTs have high purity (higher than 95%) and uniform diameter (from 1.24 to 1.38nm).This experiment indicates that the temperature strongly affects the production of SWNT; the production and purity of SWNT increase with temperature. When the temperature is 600℃, the purity is about 70% and the production of SWNT is 12g/h.
Time-dependent interface stability during directional solidification of a single phase alloy(Ⅰ) Theoritical
Authors: Lin Xin  , Li Tao  , Wang Lin-Lin  , Su Yun-Peng  , Huang Wei-Dong  ,   西北工业大学凝固技术国家重点实验室，西安　710072
Published: December 2020

The initial transient solute redistribution during directional solidification is systematically investigated by carefully comparing the current theoreltical models with experimental results. It is shown that at the transient front solute redistribution generally meets an exponential profile no matter whether there exi sts liquid convection or pure diffusion in front of the liquid/solid interface.The profile can be described by a unified formula. Based on this, a general time-dependent linear dynamic analysis of the morphological instability of a solidifying planar interface during directional solidification is carried out. It is found that the timedependent instability solution has the same form as the steadystate solution described by Mullins and Sekerka, but the timedependent concentration gradient GtC, interface velocity Vi and diffusion length l should replace the corresponding steadystate concentration gradi ent GC，interface velocity V，diffusion length DL/V in Mulli ns and Sekerka solution.
Geometric foundations of Hojman theorem\=for Birkhoffian systems
Authors: Zhang Yi  ,   苏州科技学院土木工程系，苏州　215011
Published: December 2020

This paper studies the geometric foundations of Hojman theorem for Brikhoffian s y stems. The differential equations of motion and the Hojman conservation law of t he systems are established. A proof of Hojman theorem of Birkhoffian systems is given by use of the modern differential geometry.
The conserved quantity of Hojman for mechanicalsystems with variable mass in phase space
Authors: Fang Jian－Hui  , Zhang Peng－Yu  ,   石油大学(华东)物理科学与技术学院,东营　257061
Published: December 2020

In this paper, we study the Hojman conserved quantity of Lie symmetry for mechan ical systems with variable mass in phase space under a general infinitesimal tra ns formation. The determining equations and Hojman conservation theorem of Lie symm etry of the system in phase space are obtained. An example is given to illustrat e the application of the result.
Envelope solutions to nonlinear Schr?dinger equation
Authors: Li Xiang－Zheng  , Zhang Jin－Liang  , Wang Yue－Ming  , Wang  Ming－Liang  ,   (1)河南科技大学数理系,洛阳　471003; (2)河南科技大学数理系,洛阳　471003兰州大学数学系，兰州　730000
Published: December 2020

F-expansion method proposed recently is extended to construct more exact solutio ns of nonlinear evolution equations. To be more precise, it means that instead o f the first-order ordinary differential equation(ODE) and finite power series of one variable in F-expansion met hod, we introduce similar first-order ODEs and finite power series of two varia b les, each one of which is the component of solution to ODEs. As an illust rat ive example, using this extended F-expansion method we solve nonlinear Schrdin g er(NLS) equation, an abundance of envelope solutions, especially the solutions expressed by two different Jacobi elliptic functions, to the NLS equation have b een obtai ned. Obviously, the extended F-expansion method can be applied to solve other ty pe of nonlinear evolution equations as well.
More on linear superposition method for the (2+1)－dimensional nonlinear wave equations
Authors: Lai Xian－Jing  , Zhang Jie－Fang  ,   浙江师范大学非线性物理研究所，金华　321004
Published: December 2020

In this paper, we find periodic solutions with different periods and velocities to the (2+1)-dimensional general Schdinger and Boussinesq equations by making approprite linear superpositions of known periodic travelling wave solutions in volving Jacobi elliptic functions.It is noteworthy that this linear superpositio n procedure works by virtue of some remarkable new identities involving elliptic functions.
Quantum theory of steady state photorefractive spatial solitons propagation
Authors: Jiang Jin－Huan  , Wang Yong－Long  , Li Zi－Ping  ,   北京工业大学应用数理学院，北京　100022
Published: December 2020

The system of steady state photorefractive spatial optical solitons can be descr ibed by a singular Lagrangian.To our knowledge,the commutation relations and qua ntum equations of motion are given by using corresponding principle, however it is not satisfactory since the constraints are ignored.In this paper,the commutat ion relations and quantum equations of motion are derived based on the Dirac the ory of constrained systems.The perturbation solution in screening soliton case i s found and the squeezing properties are discussed.
Direct adaptive fuzzy-neural control of unknown chaotic system
Authors: Tan Wen  , Wang Yao－Nan  ,   (1)湖南大学电气与信息工程学院，长沙　410082; (2)湖南科技大学信息与电气工程学院，湘潭　411201湖南大学电气与信息工程学院，长沙　410082
Published: December 2020

A novel direct adaptive fuzzy neural networks(FNNs)controller for a class of unc ertain nonlinear chaotic system is presented.Takagi-Sugeno fuzzy logic systems a re applied to estimate the unknown function of the chaotic system,then the param eters of adaptive FNNs control law are on-line tuned so that the tracking prob le m is realized,i.e.to force the solutions of the chaotic plant to follow a certai n given trajectory under the condition that all signals involved are uniformly b ounded.Simulation results show the validity of the obtained result.
Modified chaotic adding weight one_rank local_region forecasting for silicon content in molten iron of blast furnace
Authors: Gao Chuan－Hou  , Zhou Zhi－Min  ,   浙江大学数学系，杭州　310027
Published: December 2020

Based on the usual chaotic-weighting first-rank local-region forecas ting model, a modification is made for the predictor in matrix and vector simulation instead of single variant. Then the modified forec asting model is applied to pr edict silicon content in molten iron of the medium-sized blast furnace in China, and good results are obtained. Finally, we find that the value of Kolmogo rov entropy has a great effect on the hitting accuracy of the prediction .
H∞ tracking control for coupled spatio-temporal chaos with uncertain model based on fuzzy observers
Authors: Dou Chun－Xia  , Zhang Shu－Qing  ,   燕山大学电气工程学院,秦皇岛　066004
Published: December 2020

Due to the interactions among coupled spatio_temporal subsystems and th e model uncertainties, it is difficult to achieve tracking control for coupled s patio_temporal chaos with uncertain model. However, every subsystem of the coupl e d spatio_temporal chaos is approximated by a set of fuzzy models. Considering th at the st ates of the subsystems are not all available, a set of fuzzy observers are propo sed to estimate these states. Because it is very difficult to exactly eliminate many parameters and dynamic characters of the chaotic system, that is to say, the s yst em model is uncertain, there can be deviation between the fuzzy models and the real chaotic system due to approximation error. Based on these fuzzy models and observers, considering the model uncertainties, a H∞ fuzzy tracking contro l scheme is proposed, and the robust tracking control for the coupled spatio_tem pora l chaos with the uncertain model is achieved by the above scheme. A linear matri x inequali ty is employed to represent the feedback controller, the parameters of the contr oller being obtained by using the convex optimization techniques of linear matri x inequalites. The stability of the system is guaranteed and the tracking performances are tested by a simul ation example.
The simulation of ionic radial density in high intensity ion beam*
Authors: Bai Long  , Weng Jia－Qiang  , Fang Jin－Qing  , Luo  Xiao-Shu  ,   (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

The ionic beam which exhibits a Kapchinsky_Vladimirsky distribution is studied in this paper. Not only the halo is found, but also the ionic radial den sity which has changed is discovered when the ionic beam is in accelerator chan nels. By delay feedback control method, the halo is removed. Moreover as long as the proper parameters are chosen, the density uniformity can be found at beam' s center.
Control of beam halo-chaos via exterior magnetic field switching control*
Authors: Gao Yuan  , Luo  Xiao－Shu  , Weng Jia－Qiang  ,   (1)广西工学院电子信息与控制工程系,柳州　 545006; (2)广西师范大学物理与信息工程学院,桂林　541004
Published: December 2020

In this paper, the magnetic field parametric switching method for controlling t he beam_halo chaos in the period_focusing channel(PFC) is studied. The law of t he parametrical switching control is presented . The simulation results demonstr ated that the chaotic envelo pe of the ion beam can be controlled well by this method. Then the method is app lied to the multi_particle model with the period_focusing magnetic field channel . The PFC simulation results show that beam halo_chaos for five different kinds of beams can be controlled well. The beam halos and its regeneration can be eliminated. This method is easy to realize in experiment.The research offers a valuable reference for the design of the PFCs in the high_current linea r proton accelerators.
Effects of the stochastic delay probability on traffic flow*
Authors: Chen Yan－Hong  , Xue Yu  ,   (1)广西大学物理系,南宁　530004; (2)广西大学物理系,南宁　530004上海大学上海市应用数学与力学研究所,上海　200072
Published: December 2020

Considering the effects of different factors on the stochastic delay probability , we have classified the delay probability into three cases. The first case, cor responding to the deceleration state, has a large delay probability if anticipan t veloc ity is larger than the gap between the successive cars. The second one, correspo nding to the leader following stably, has an intermediate delay probability if t he anticipant velocity is equal to the gap. The last is the one with acceleratio n with the minimum delay probability. The fundamental diagram obtained by the nu merical simulation shows the different properties compared with that by the NaSc h model, in which there exist two different jamming regions corresponding to the coexistent congestion and jamming with different properties of shock wave.
Intensity-gradient cooling of atoms in a localized-hol low beam*
Authors: Yin Jian-Ping  , Gao Wei-Jian  ,   (1)华东师范大学物理系，光谱学与波谱学教育部重点实验室，上海　200062; (2)苏州大学物理系,苏州　215006
Published: December 2020

In this paper, we propose a new scheme to cool and trap neutral ato ms by using a blue-detuned localized hollow beam (LHB), and studied the dynamica l process of intensity-gradient cooling of the trapped atoms in the LHB by means of Monte-Carlo simulations. Our study shows that an ultracold atomic sample wit h a temperature of ～5 μK and an atomic density of 1012—1013/cm 3 can be obtained in our single LHB, and this atomic density can be con trolled by changing the relative aperture of the lens system. So, such a LHB can be used to realize an all-optical atomic Bose-Einstein condensation.