bluuebunny/crossref_metadata_2025 huggingface dataset:
The study on the Peierls phase transition of TTF-TCNQ
Authors: Zhang Hong-Qun  , Liu Shao-Jun  , Li Rong-Wu  ,   北京师范大学物理系，北京  100875
Published: December 2020

According to Peierls phase transition theory on the basis of the electron-phonon interaction, the Peierls phase transition temperature of a one-dimensional organic conductor TTF-TCNQ is computed by using the deformation potential model with the data calculated by using a semi-empirical crystal orbital method. The result indicates that the Peierls phase transition temperature of TTF chains is lower than that of TCNQ chains, which demonstrate that the electron-phonon coupling interaction in TTF chains is weaker than that in TCNQ chains, and the metal-insulator phase transition in TTF-TCNQ at 54K mainly takes place in TCNQ chains.
Analysis of surface leakage and 1/f noise on long-wavelength infrared HgCdTe photodiodes
Authors: Sun Tao  , Chen Xing-Guo  , Hu Xiao-Ning  , Li Yan-Jin  ,   中国科学院上海技术物理所功能材料器件中心，上海  200083
Published: December 2020

The long-wavelength infrared Hg1-xCdxTe photovoltaic dete ctors with x=0217 passivated by single ZnS layer and dual (CdTe+ZnS) layers were fabricated in the same wafer. The fabricated devices were characterized by meas urements of dark currents and 1/f noise. The diode passivated by dual (CdTe+ ZnS) layers showed a higher performance compared to the diode passivated by the single ZnS layer at high reverse bias, and modeling of diode dark current mechan isms indicated that the performance of the diode passivated by single ZnS was st rongly affected by tunneling current related to the surface defects, which was r esponsible for the dark currents and 1/f noise characteristics. By the analy sis of x-ray reciprocal space map (RSM), it was found that the Qy dir e ction broadening of HgCdTe epitaxial layer passivated by ZnS was wider after pas sivation, which confirmed the existence of defects in the surface of HgCdTe epit axial layer passivated by ZnS. In order to investigate the effect of surface pas sivation on the stability of two kinds of diodes, dark currents and 1/f nois e of the diodes were measured after vacuum baking for 10 h at 80℃. The dark cur rent mechanisms indicated that the performance of the diode passivated by single ZnS was strongly affected by the surface defects. By the analysis of RSM, It wa s found that the Qy direction broadening of HgCdTe epitaxial layer pa s sivated by ZnS was wider after high-temperature baking, which also confirmed the existence of defects in the surface of HgCdTe epitaxial layer passivated by ZnS after baking.
Electrical property of rapidly solidified Co-Cu peritectic alloys
Authors: Xu Jin-Feng  , Wei Bing-Bo  ,   西北工业大学应用物理系，西安  710072
Published: December 2020

The microstructure formation and phase selection characteristics of Co-Cu peritectic alloys during rapid solidification are investigated experimentally. The re lationships between such physical factors as cooling rate, microstructure morpho logy, crystal orientation, and alloy resistivity are further analyzed. The exper imental results show that rapid solidification makes the Co solubility in (Cu) p hase extend up to 20%Co. If Cu concentration is more than 80%Cu, the peritectic transformation L+αCo→(Cu) is suppressed, and the (Cu) phase can directly preci pitate from the undercooled alloy melt. When the Cu concentration is in the rang e of 40%-70%Cu, the liquid phase separation of the alloys is also suppressed, and the microstructure in the direction of ribbon thickness consists of two crysta l zones. In the fine crystal zone, the αCo and (Cu) phases nucleate and grow co mpetitively, the tiny equiaxed (Cu) dendrites are distributed in the αCo matrix homogeneously, whereas in the coarse crystal zone the αCo is the leading phase , where Cu-rich phase exists in the grain boundary of αCo dendrites. With the increase of cooling rate, the microstructure is refined and the amount of grain boundary increases, resulting in the rise of alloy resistivity. If the grain bou ndary reflection coefficient r＝0996—0999, the electrical resistivity o f Co-Cu peritectic alloys can be predicted theoretically.
Synchronization in the Genesio-Tesi and Coullet systems with nonlinear feedback controlling
Authors: Liu Yang-Zheng  , Fei  Shu-Min  ,   (1)东南大学自动控制系,南京  210096; (2)南京工程学院基础部,南京  210013;东南大学自动控制系,南京  210096
Published: December 2020

The characteristics of the Genesio-Tesi and Coullet systems are analyzed. Two systems are topologically inequivalent, but they have similarity in the strange attractor structure. Chaos synchronization between the two systems is realized via nonlinear feedback control. The nonlinear feedback controller is designed based on the stability theory， and the area of feedback gain is taken. The simulatio n result verifies the conclusion.
Phase synchronization of R?ssler in two coupled harmonic oscillators
Authors: Hao Jian-Hong  , Li Wei  ,   (1)北京师范大学物理系,北京  100875;北京应用物理与计算数学研究所,北京  100088; (2)华北电力大学信息工程系,北京  102206;石家庄学院物理系,石家庄  050801
Published: December 2020

Phase synchronization dynamics of Rssler oscillator in two coupled harmonic oscillators is discussed based on stability analysis of the coupled chaotic system. Different from the case of only one coupled periodic oscillator, in two o scillators one or the other harmonic oscillator will entrain alternately (or th ey will entrain exclusively). We find that depending on the stability of the system, the duration of the phase synchronization is affected by parameters of t he oscillator. The simulated results agree with our theoretic values within the range of error.
Simulation study on single particle in controlling halo-chaos
Authors: Liao Gao-Hua  , Weng Jia-Qiang  , Cheng Li-Chun  , Fang Jin-Qing  ,   (1)广西师范大学物理与信息工程学院，桂林  541004; (2)桂林电子工业学院信息材料科学与工程系，桂林  541004; (3)中国原子能科学研究院，北京  102413
Published: December 2020

In this paper, we adopt the Particle_in_Cell(PIC) program to study the transverse movement of particles in high_intensity beam. It is found that the transverse movement of halo particles in not always in halo region. The movement is restricted in a narrow region after the beam is controlled. Changes of root_mean_squared radius are nearly periodic. According to the regulation and variation of root_mean_squared radius, a new self_adaptive controller method is put forward. This research demonstrates that the halo can be completely controlled by the controller quickly. There is no need to precisely calculate the coefficient of controller, and the controller can work well even if the system parameters are changed.
Period-doubling bifurcation analysis of stochastic van der Pol system via Chebyshev polynomial approximation
Authors: Ma Shao-Juan  , Xu  Wei  , Li Wei  , Jin Yan-Fei  ,   (1)西北工业大学应用数学系,西安  710072; (2)西北工业大学应用数学系,西安  710072;西北第二民族学院信息与计算科学系,银川  750021
Published: December 2020

Chebyshev polynomial approximation is applied to the period-doubling bifurcation problem of a stochastic van der Pol system with bounded random parameters and subjected to harmonic excitations. Firstly, the stochastic system is reduced to its equivalent deterministic one, through which the response of the stochastic s ystem can be obtained by numerical methods. Nonlinear dynamical behavior related to various forms of stochastic period-doubling bifurcation in the stochastic sy stem is explored. Numerical simulations show that similar to their counterpart i n deterministic nonlinear system, various forms of period-doubling bifurcation m ay occur in the stochastic van der Pol system, but with some modified features. Numerical results also show that Chebyshev polynomial approximation can provide an effective approach to dynamical problems in stochastic nonlinear systems.
X-ray emission in lithium-like and helium-like argon ions colliding with molybdenum surfaces
Authors: Zhang Yan-Ping  , Yang Zhi-Hu  , Du Shu-Bin  , Chen Xi-Meng  , Zhao Yong-Tao  , Zhang Xiao-An  , Cui Ying  , Zhang Hong-Qiang  , Xu Xu  , Shao Jian-Xiong  , Xiao Guo-Qing  ,   (1)兰州大学现代物理系，兰州  730000; (2)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;中国科学院研究生院，北京  100039; (4)中国原子能科学研究院，北京  102413
Published: December 2020

We have measured the spectra and yields for Ar K and Mo L x-rays from Ar 15+ and Ar16+ ions colliding with molybdenum (Mo) surfaces . The spec tra and yields are measured as a function of the projectile kinetic energy. In t he case of Ar15+ -Mo, both Ar K x-rays and Mo L x-rays are observe d, and the yields of Ar K x-rays are related to the projectile kinetic energ y, the potential energy of hollow atom formed in the interaction, the competitio n of the x-rays emitting from the projectile and the target etc. But in the case of Ar15+-Mo, Mo L x-rays are observed only. The yields of Mo L x- rays induced in both cases increase with the projectile kinetic energy.
Test and verification of temporal aberration theory for electron optical imaging systems by an electrostatic concentric spherical system model
Authors: Zhou Li-Wei  , Li Yuan  , Zhang Zhi-Quan  , Monastyrski M. A.  , Schelev M. Y.  ,   (1)北京理工大学信息科学技术学院，北京  100081; (2)俄罗斯科学院普罗霍洛夫普通物理研究所，莫斯科  119991; (3)装甲兵工程学院，北京  100072
Published: December 2020

On theory of temporal aberration of dynamic electron optical imaging systems, we have put forward two methods: “τ-variation method" and “direct integral method" to calculate the temporal aberration coefficients. The difference betwe en them is that the “τ-variation method"needs to solve the differential eq uations for geometrical temporal aberration coefficients of second order, while the “direct integral method" needs only to carry out the integral calculations. The aim of the present paper is to test and verify the correctness of the two m ethods using an electrostatic concentric spherical system model. Results show th at these two methods can obtain identical solutions and the solutions of tempora l aberration coefficients of dynamic electron optical imaging systems are the sa me with the analytical solutions. Thus it can be concluded that these two method s are equivalent and correct, but the “direct integral method" is more convenie nt for computation and it could be suggested to use in the practical design.
Two-dimensional patterned nc-Si arrays prepared by the method of laser interference crystallization
Authors: Zou He-Cheng  , Qiao Feng  , Wu Liang-Cai  , Huang Xin-Fan  , Li Xin  , Han Pei-Gao  , Ma Zhong-Yuan  , Li Wei  , Chen Kun-Ji  ,   南京大学物理系，固体微结构物理国家重点实验室，南京  210093
Published: December 2020

The method of laser_induced crystallization combining with the phase-shifting grating mask (PSGM) was carried out to fabricate nanocrystal silicon (nc-Si) with the two-dimensional (2D) patterned distribution within a-SiNx/a- Si:H/ a-SiNx sandwiched structure grown on the SiO2/Si or fuse d quartz subst rate by plasma-enhanced chemical vapor deposition technique. The thicknesses of a-Si:H and a-SiNx layer are 10 and 50nm, respectively. The results of at omic force microscopy, cross-section transmission electron microscopy and high r esolution transmission electron microscopy show that the controllable crystalliz ed regions within the initial a-Si:H layer are selectively formed with a diamete r of about 250 nm and are patterned with the same 2D periodicity of 20 μm as that of the PSGM. Si nano-crystallites，the size of which is almost the same as the thickness of the a-Si:H layer, are formed in the crystallized regions, and h ave preferred orientation.
Upconversion luminescence of lead halide-modified Tm3+/Yb3+-codoped tellurite glasses
Authors: Xu Shi-Qing  , Zhang Zai-Xuan  , Fang Da-Wei  , Dong Qian-Min  , Jiang Zhong-Hong  ,   (1)中国计量学院信息工程学院，杭州  310018; (2)中国计量学院信息工程学院，杭州  310018;中国科学院上海光学精密机械研究所，上海  201800;中国科学院研究生院，北京  100039; (3)中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

The thermal stability, Raman spectra, and upconversion luminescence spectra of lead halide-modified Tm3+/Yb3+-codoped tellurite glasses ha ve been investigated, and the upconversion luminescence mechanism of Tm3+/Yb 3+-codoped oxyhalide tellurite glasses were analyzed. The results sho wed that mi xed lead halide-modified Tm3+/Yb3+-codoped tellurite glass es possess good thermal stability, low phonon energy and intense upconversion blue lumines cence, which indicates that mixed lead halide-modified Tm3+/Yb3+ -cod oped tellurite glasses can be used as a kind of potential host materials for upc onversion blue lasers.
Determination of the extinction coefficient of a weakly absorbing multilayer system
Authors: Gu Pei-Fu  , Chen Hai-Xing  , Zheng Zhen-Rong  , Liu Xu  ,   浙江大学现代光学仪器国家重点实验室,杭州  310027
Published: December 2020

Based on a measured peak transmittance of a narrow band filter, the extinction coefficients of weakly absorbing thin films in a multilayer system can directly be calculated. This is a new method used for determination of the extinction coefficients of thin films in a weakly absorbing multilayer system with very easy to do and very high precision. The absorbing expression in a weakly absorbing interference narrow band filter is deduced. The principle of determination of the extinction coefficient is illustrated and the precision of the calculated extinction coefficient in a Ta2O5/SiO2 filter used in a dense wavelength division multiplexing system is analyzed.
Flow equations for solving energy spectrum （T≠0）of the t-J model
Authors: Wang Hong  , Lou Ping  , Zhuang Yong-He  ,   (1)安徽大学物理与材料科学学院，安徽省信息材料与器件重点实验室,合肥   2300 39; (2)中国电子科技集团公司第43研究所,合肥  230022
Published: December 2020

The t_J model is one of the most important models that is often used to stud y the theory of the effect of strong electron correlations and high_Tc superconductivity. In this article, the method of renormalization group is use d to investigate the t_J model， and the elementary excitation energy spectra of t_J model (Ｔ≠０) are obtained by the flow equations. The result is compared with that of Green's function method and agrees with its result. At th e same time, the result of renormalization group method is the analytical soluti on while that of Green’s function method is the numerical solution.
A molecular dynamics study on lubricant perfluoropolyether in hard disk driver
Authors: Li Xin  , Hu Yuan-Zhong  , Wang Hui  ,   清华大学摩擦学国家重点实验室，北京  100084
Published: December 2020

The structure of nanoscale lubricant films perfluoropolyether (PFPE) and its mob ility on a solid surface are important for the service durability and reliabilit y of the computer head_disk device. Molecular dynamic simulations based on a coa rse_grained bead_spring model are adopted to investigate the static properties s uch as molecular conformation, bead density, end bead density and the dynamic pr operties such as self_diffusion coefficient as a function of the wall effect and the functionality effect of PFPE films. The simulation results of static proper ties show that there is a monolayer in surface layer for nonpolar PFPE, while th ere is a complex layered structure for polar PFPE. While the simulation results of dynamic properties show that the diffusivity of PFPE films is enhanced by wal l effect but decreased by the functionality effect.
In-plane anisotropy of iron single-crystal thin film using x-ray magnetic circular dichroism
Authors: Li Rui-Peng  , Wang Jie  , Li Hong-Hong  , Guo Yu-Xian  , Wang Feng  , Hu Zhi-Wei  ,   (1)科隆大学物理系，德国科隆  D-50937; (2)中国科学技术大学国家同步辐射实验室，合肥  230029
Published: December 2020

X-ray magnetic circular dichroism (XMCD) in the absorption of the single-crystal iron thin film deposited epitaxially on MgO substrate is studied to get the spin and orbital moment. The experiments show that along with different crystal axes, the change of orbital moment of Fe atoms is about 600%, the change of the spin moment is only about 50%, but the change of total moment is not so large. Researching the anisotropy by means of routine methods, the relation between the magnetic moment and the anisotropy of the thin film is studied.
Concentration quenching mechanism in erbium-doped tellurite glass
Authors: Yu Chun-Lei  , Dai Shi-Xun  , Zhou Gang  , Zhang Jun-Jie  , Hu Li-Li  , Jiang Zhong-Hong  ,   中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

The fluorescence properties of Er3+:4I13/2→4I15/2 transition in tellurite glasses have been investigated as a f u nction of the Er3+ concentration. The critical distance R0 for whic h concentration quenching will happen, and the interaction microparameter C Er-Er in tellurite glasses were determined on the basis of the energy migr ation model of Dexter theory. The value of CEr-Er in the proposed tel lurite glass was compared with that in other glass hosts. Finally, the concentration quenching mechanism described using a model based on energy transfer and quenching by hydroxyl groups was presented.
Fabrication of microcrystalline silicon thin film and the study of its microstructure and stability
Authors: Zhang Xiao-Dan  , Zhao Ying  , Gao Yan-Tao  , Zhu Feng  , Wei Chang-Chun  , Sun Jian  , Geng Xin-Hua  , Xiong Shao-Zhen  ,   南开大学光电子薄膜器件与技术研究所，天津  300071;南开大学光电子薄膜器件与技术天津市重点实验室，天津  300071;南开大学光电信息技术科学教育部重点实验室，天津  300071
Published: December 2020

A series of microcrystalline silicon thin films were fabricated by very high frequency plasma-enhanced chemical vapor deposition at different substrate temperat ures (Ts). Analysis of materials structure was conducted using Fourie r tra nsform infrared (FTIR). The results showed that hydrogen content of the samples decreased with the increase of Ts. The results of FTIR and secondary ion m ass spectra indicated that the oxygen content of the samples increased with the increase of Ts. Compared with those at higher Ts, samples prepared at low Ts easily adsorbed oxygen, and showed bad stability.
Field emission properties of diamond-like carbon and carbon nitride films deposited by the electrochemical method
Authors: Ye Fan  , Xie Er-Qing  , Li Rui-Shan  , Lin Hong-Feng  , Zhang Jun  , He De-Yan  ,   兰州大学物理科学与技术学院，兰州  730000
Published: December 2020

Diamond-like carbon (DLC) and carbon nitride (CNx) films were deposit ed successfully by the electrochemical method.The conditions of deposition were discussed also.Scanning electron microscope and Fourier transform infrared technigue were used to investigate the surface morphology and the bonding structure.The results of the field emission show that the turn-on fields of DLC films and CNx films are 88 and 10V/μm respectively.Under the field of 23V/μm,their current densities are as high as 10 and 037 mA/cm2, respectively .
Effects of open dangling end on the transport properties of single-wall carbon nanotubes
Authors: Chen Qin  , Li Tong-Cang  , Shi Qin-Wei  , Wang Xiao-Ping  ,   (1)中国科学技术大学合肥微尺度物质科学国家实验室，合肥  230026; (2)中国科学技术大学物理系，合肥  230026; (3)中国科学技术大学物理系，合肥  230026;中国科学技术大学合肥微尺度物质科学国家实验室，合肥  230026
Published: December 2020

The effects of the dangling end on the electronic transport properties of the single-wall carbon nanotubes (CNTs) have been investigated, based on the tight-binding model and Landau formula. It is found that the conductance oscillates per iodically near the Fermi energy in the CNT with a finite-length open dangling en d. Both slow and rapid oscillations occur in armchair CNTs, but only the rapid o scillation appears in zigzag ones. The period of the rapid oscillation decreases with increasing the length of the dangling end. Moreover, the mean conductance of the CNTs with finite-length open dangling end is about twice as that with inf inite-length open dangling end. Some relevant application is also discussed.
A new approach to study the dynamics of the deformation of vesicles discrete-space variational method
Authors: Li Jian-Feng  , Zhang Hong-Dong  , Qiu Feng  , Yang Yu-Liang  ,   复旦大学高分子科学系，教育部聚合物分子工程重点实验室，上海  200433
Published: December 2020

A new approach, namely discrete-space variational method(DSVM) is developed to study the dynamics of deformation of a two-dimensional vesicle. It can overcome the difficulties in the previously analytical or numerical methods which were de signed to solve the shape-equation of the vesicle. Also it is a correct and stab le method because its computational results accord well with those gained by the other methods. Furthermore, it can be used to describe the three-dimensional ve sicle without any symmetry, and takes into account the long-range interaction fo r avoiding the intersection of membranes.
Study of the technique of 4-face coated pyramid prism for measurement of upper atmospheric wind field
Authors: Tang Yuan-He  , Zhang Chun-Min  , Liu Han-Chen  , Chen Guang-De  , He Jian  ,   (1)西安工程科技学院理学院,西安  710048; (2)西安交通大学理学院,西安  710049; (3)西安交通大学理学院,西安  710049;西安理工大学理学院,西安  710048
Published: December 2020

The principle of measurement of upper atmospheric wind field has been described first by using the technique of 4-face coated pyramid prism (CPP). If the anti-r efraction films is coated by λ/4（λwavelength）stepped optical path difference (OPD), there can be obtained 4 interference intensities for one fringe simultan eously to measure the upper atmospheric wind field. After correlative parameters of CPP technique are calculated, the CPP's vertex angle must be larger than 24 degree and the width of symmetric incident beam to CPP vertex may be less than 8 mm by LF7 prism and MgF2 anti-refraction films, so that it can be use d to dete ct the upper atmospheric wind for 9°×9° interferometer's field of view (FOV) and CCD 4.5°×4.5°. Finally, we made a simulation test for 2-face coated prism , two group of speckle patterns of deflection light and intensities on CCD have been obtained for prism vertex angle 60°　and ９０°. By copying the two-speckl e patterns to obtain CPP's four ones, it can achieve “four intensities way" for upper atmospheric wind field measurement. The test result is made sure of this way to measure the atmospheric wind. This way has developed the technique of pas sive measurement of wind field.
An electron momentum spectroscopy investigation on the 1a′ inner valence orbital of cyclopentene
Authors: Su Guo-Lin  , Ren Xue-Guang  , Zhang Shu-Feng  , Ning Chuan-Gang  , Zhou Hui  , Li Bin  , Huang Feng  , Li Gui-Qin  , Deng Jing-Kang  ,   清华大学物理系原子分子纳米科学教育部重点实验室，北京  100084
Published: December 2020

The ionization energy spectrum and the spherically averaged momentum distribution of 1a′ inner valance orbital for cyclopentene have been investigated by using a high resolution (ΔE=1.15eV, Δp≈0.1a.u.) electron momentum spectrometer. The impact energy was 1200eV plus binding energy (i.e. 1202—1234eV) and a symmet ric non-coplanar kinematics was employed. The experimental momentum profile of the 1a′ inner valence orbital is obtained and compared with the theoretical m omentum distributions calculated by using Hartree-Fock and density functional th eory methods with the basis sets STO-3G, 6-31G, 6-311++G** and au g-cc-pVTZ. The pole strength of the 1a′ inner valence orbital is estimated and the electron correlation effects are discussed.
Dynamic properties of a Λ-type atom embedded in photonic crystal
Authors: Huang Xian-Shan  , Yang Ya-Ping  ,   同济大学物理系，上海  200092
Published: December 2020

The dynamical properties and spectrum characteristics of a Λ-type atom with an external field embedded in three-dimensional photonic crystals are investigated . With the help of numerical calculation and theoretical analysis, we find that the populations of the upper and lower levels display quasi-oscillation, and the frequency and amplitude of the oscillation is greatly affected by the intensity of the external-driving field Ω, the detuning δ　and the background decay of the upper level γ.　Ｓpontaneous emission of the atom is apparently influenced by the relative position of the upper level from the forbidden gap. Furthermore, the properties of the emission field around the atom are analyzed by means of s pontaneous emission spectrum.
Theoretical analysis of fs-laser induced micro-explosion in fused silica
Authors: Xu Shi-Zhen  , Jia Tian-Qing  , Sun Hai-Yi  , Li Xiao-Xi  , Cheng Zhao-Gu  , Feng Dong-Hai  , Li Cheng-Bin  , Xu Zhi-Zhan  ,   中国科学院上海光学精密机械研究所强场激光物理国家重点实验室，上海  201800
Published: December 2020

Based on the avalanche model, the evolution of femtosecond laser induced micro-e xplosion in fused silica was investigated. The microscopic processes, including the production of conduction band electron (CBE), laser energy deposition, CBE a nd energy diffusion were solved by a finite element method in two-dimensional cy lindrical coordinates. The accumulated net charge and the electrostatic field we re also calculated. The results indicate that the CBE and energy diffusions play an important role in the micro-explosion in dielectrics.
Hyperfine stucture during nanocrystallization of amorphous Fe73.5Cu1Nb3Si13.5B9 alloy irradiated by laser
Authors: Chen Sui-Yuan  , Liu Chang-Sheng  , Li Hui-Li  , Cui Tong  ,   东北大学材料与冶金学院，沈阳  110004
Published: December 2020

The material composed of a definite amount of nanocrystalline phase α-Fe(Si) with a double-phase structure was produced by laser irradiation on the amorphous Fe735Cu1Nb3Si135B9 alloy with a laser power ranging from 50 to 300W, scanning speed 20mm/s, laser beam spot 20mm. Hyperfine structures of the nanocrystallized samples were analyzed by Mssbauer spectra. Experimental result shows that after the CO2 laser irradiated on the amorphous allo y Fe735Cu1Nb3Si135B 9, its hyperfine magnetic field dist ribution transformed from a single peak to double peaks with the change of laser power. When irradiated at a high laser power, it formed a double-peak structure and the peaks moved to a high field position. Nanocrystallization of amorphous Fe7 35Cu1Nb3Si135B9 ir radiated by a higher laser power produces fou r hyperfine structures, i.e. two primary crystal phases with relatively small hy perfine magnetic field and two nanocrystalline phases with a relatively large hy perfine magnetic field. The major crystal phase is the α-Fe(Si) phase of DO3 whose hyperfine magnetic field is comparatively larger (17—25MA/m).
Effects of noise on spectral phase reconstruction with wavelet analysis
Authors: Deng Yu-Qiang  , Zhang Zhi-Gang  , Chai Lu  , Wang Qing-Yue  ,   (1)天津大学精密仪器与光电子工程学院超快激光研究室，光电信息技术科学教育部 重点实验室，天津  300072; (2)天津大学精密仪器与光电子工程学院超快激光研究室，光电信息技术科学教育部 重点实验室，天津  300072;北京大学信息学院量子电子学研究所，北京  100871
Published: December 2020

We have investigated the accuracy of wavelet analysis of spectral shearing inter ferometry signal with noisy data. Specifically, we have examined at the effects of additive noise, multiplicative noise, and quantization of the interferogram o n the reconstruction of the spectral phase, and revealed that the wavelet transf orm is a robust technique to retrieve spectral phase from the noise background. We also show that the phase of a femtosecond pulse can be identified from the tr ace of wavelet transform.
Density modulation produced by ultrashort laser pulses and the phase reflection induced in underdense plasmas
Authors: Zhang Qiu-Ju  , Sheng Zheng-Ming  , Cang Yu  , Zhang Jie  ,   (1)山东师范大学物理与电子科学学院，济南  250014; (2)中国科学院物理研究所光物理开放实验室，北京  100080
Published: December 2020

It is shown theoretically and by particle-in-cell simulations that the interferi ng fields of the incident and reflected laser pulses can produce deep plasma den sity modulations in underdense pre-plasmas.This occurs within a few tens of lase r cycles if the incident laser pulse is at moderate intensities such as 10 15W／cm2Such density modulations can serve as a Bragg reflector ,which results in phase reflection from underdense plasmas.Because the deep dens ity modulations are just a period of half a wavelength in the plasma，the reflec ted wave reaches the maximum by resonance with a reflectivity up to near 100％.T he phase reflection can also be observed from the plasma with a linear density p rofile，which can significantly reduce the laser absorption by fusion targets.
Influence of frequency on magnetic properties of Fe73.5Cu1 Nb3Si13.5B9 and the explanation
Authors: Yang Quan-Min  , Wang Ling-Ling  ,   (1)湖南大学应用物理系，长沙  410082; (2)连云港师范高等专科学校物理系，连云港  222006
Published: December 2020

According to the research of the mesoscopic structure of Fe73.5Cu 1Nb 3Si135B9 by AFM, we propose a model for n anostructured soft magnetic properties; and explain the influence of the frequency on the magnetic properti es successfully using the model. The model possesses the characteristic of Herze r's or Ji Song's model, and supplement their deficiency. We also study the influ ence of the conductivity σ and the permeability μ on the magnetic properties o f Fe73.5Cu1Nb3Si135B9 for the first time.
Synthesis of GaN nanowires and nano-pyramids in a two-hot-boat chemical vapor deposition system via an In-doping technique
Authors: Liu Shi-Feng  , Qin Guo-Gang  , You Li-Ping  , Zhang Ji-Cai  , Fu Zhu-Xi  , Dai Lun  ,   (1)北京大学物理学院，北京  100871; (2)北京大学物理学院，北京  100871;北京大学电子显微镜实验室，北京  100871; (3)北京大学物理学院，北京  100871;人工微结构和介观物理国家重点实验室，北京  100871; (4)中国科学技术大学物理系，合肥  230027; (5)中国科学院半导体研究所，北京  100083
Published: December 2020

A two-hot-boat chemical vapor deposition system was modified from a thermal evaporation equipment. This system has the advantage of high vacuum, rapid heating rate and temperature separately controlled boats for the source and samples. These are in favor of synthesizing compound semiconducting nano-materials. By the system, we have synthesized high-quality wurtzite single crystal GaN nanowires and nanotip triangle pyramids via an in-situ doping indium surfactant technique on Si and 3C-SiC epilayer/Si substrates. The products were analyzed by x-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, and photoluminescence measurements. The GaN nanotip triangle pyramids, synthesized with this novel method, have potential application in electronic/ photonic devices for field-emission and laser.
Effect of microstructure on the coercivity of Fe40—45Cr30—35Co20—25Mo0—4Zr0—2 alloy
Authors: Li Teng  , Li Wei  , Pan Wei  , Li Xiu-Mei  ,   钢铁研究总院功能材料研究所，北京  100081
Published: December 2020

We have studied the magnetic properties, microstructure, and mechanical properti es of a high-coercivity FeCrCo alloy. Based on the experiments, the high-coerciv ity can be obtained by selecting suitable composition and heat treatment process . According to the TEM and XRD results, we drew a conclusion that the main eleme nt and the minor metallic dopants control effectively the conformation of phases . Thermomagnetic treatment induces the separation of the ferromagnetic and param agnetic phases, and a spinodal structure forms that results in magnetic-hardenin g. The large composition contrast between the two phases could improve the coer civity of the FeCrCo alloy obviously
Mode-controlled four-wave-mixing in the birefringent microstructure fiber by femtosecond laser pulses
Authors: Hu Ming-Lie  , Wang Qing-Yue  , Li Yan-Feng  , Wang Zhuan  , Chai Lu  , Zhang Wei-Li  ,   天津大学精密仪器与光电子工程学院超快激光研究室 光电信息技术科学教育部重点实验室(天津大学),天津  300072
Published: December 2020

Birefringent microstructure fibers are shown to allow efficient gereration of anti-Stokes line emission as a result of four-wave-mixing in higher mode by using unamplified femtosecond Ti:sapphire laser pulses.Intense blue-shifted lines with different central wavelength were generated in the high-delta (i.e.high-air filling in the cladding) microstructure fiber with axis sizes 50 and 46 μm by femtosecond laser pulses with 35-fs in duration,820nm in central wavelength and 4nJ in energy per pulse.The experimental result shows that phase-matched four-wa ve mixing in higher-order modes of microstructure fibers allows unprecedentedly high efficiencies of anti-Stokes frequency conversion to be achieved for subnano joule femtosecond laser pulses.The dependence factor of the four waves mixing in birefringent microstructure fiber is compared and analyzed.Good agreement betwe en the theory and experiment is achieved.
Effect of Tm3＋-doping concentration on the spectral properties in tellurite glass
Authors: Chen He  , Liu Yue-Hui  , Yao Xiao-Xu  , Feng Zhou-Ming  ,   特种功能材料及其制备新技术教育部重点实验室,华南理工大学光通信材料研究所,广州  510640
Published: December 2020

The tellurite glass 70TeO2-20WO3-10ZnO in different Tm3+-doping co ncentration were prepared. According to the absorption spectra,the Judd-Oflet strength parameters were calculated by using Judd-Ofelt theory. The spontaneous-emission probabilities,branch ratios and radiative lifetime of each level of Tm3＋ were given.The emission spectra of Tm3＋-doping in various concentrations were studied.The effective bandwidth and stimulated emission cross-section at the peak wavelength of the emission band were also investigated. Aft er comparing the spectral properties at various Tm3＋ concentra tions, we concluded that the luminescence intensity and effective bandwidth were maximum when the Tm3＋-doping concentration ranges from 0.8wt%—1wt%. The Tm3＋-doped tellurite glass is an ideal host for optical ampli fier working on S-band.
The instantaneous radiant exitance of non-static black holes
Authors: Meng Qing-Miao  ,   山东菏泽学院物理系,菏泽  274015
Published: December 2020

Selecting the advanced Eddington coordinates, and adopting the statistical method ,the instantaneous radiant exitance of non_static black hole is calculated. It is found that the instantaneous radiant emittance of non_static black hole is not only related to the radiant exitance by supposing it is in the state of thermal equilibrium, but also related to the rate of change and the temperature of its event horizon, and the absorption coefficient and the radiation coefficient of the black hole. In the situation of the spherically symmetric non_static black hole, the instantaneous radiant exitance of the black hole is always proportional to quartic power of temperature of the event horizon of black holes at anytime.
Lattice complexity and fine-graining of symbolic sequence
Authors: Ke Da-Guan  , Zhang Hong  , Tong Qin-Ye  ,   浙江大学生物医学工程系，杭州  310027
Published: December 2020

A new measure of complexity for finite symbol sequences, named as lattice comple xity, is presented, based on LempelZiv complexity and the symbolic dynamics of onedimensional iterated maps system. To make lattice complexity distinguished from LempelZiv measure, an approach called finegraining method is also prop osed. When finegraining order is small enough, the two measures are almost equ al. When finegraining order goes to large, the differentiation between them be comes apparent. Applying these measures to studies of logistic map, we find thos e be regarded as complex sequences by lattice complexity are clearly generated a t the edge of the chaotic region. The derived properties of the measures are als o discussed.
Studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of Na2 molecule
Authors: Ren Wei-Yi  , Sun Wei-Guo  ,   (1)四川大学原子分子物理研究所,化工学院,成都  610065; (2)四川大学原子分子物理研究所,化工学院,成都  610065;西华师范大学理论物理研究所,南充  637002
Published: December 2020

Modern experimental methods or accurate quantum theory methods usually may obtain a vibrational energy subset［Ev］ containing m energies, but it may be very difficult to have all the excited highlying vibrational energies f or the electronic states of most diatomic molecules. Since the full vibrational spectrum and the molecular dissociation energies of the electronic states of Na 2 molecule are very important in many studies and applications, the vibrationa l spectroscopic constants and the full vibrational spectra of some electronic st ates of Na2 molecules are acqnired using the algebraic method (AM), and the di ssociation energy (DE) of these states are obtained using the algebraic energy m ethod (AEM). The results show that AM can give accurate vibrational spectroscopi c constants and correct full vibrational energy spectrum {Ev} from experim ental vibrational energy subset［Ev］, and the molecular dissociation energies obtained using the AEM have much better accuracy than those generated u sing the vibrational constants given in the literature. The AEM can give reliabl e values of the dissociation energies for some excited electronic states whose D E may not be available in the literture.
The quantum description of polarization states of light and its evolutions in the processes of interaction with atoms
Authors: Dong Chuan-Hua  ,   上海大学物理系,上海  200436
Published: December 2020

The quantum theory of polarizing light and the Stokes operators are applied to the study of the evolutions of polarization states of light in the processes of i nteraction with atoms in the case with or without Kerr medium. The non_classic b ehavior in the fluctuations of Stokes parameters for the polarizing light and th eir squeezing are investigated. The polarization ellipse, the degree of polariza tion of the field in quantum optics and the signal_to_noise ratio in the Stokes parameters are discussed. It is shown that the modulated oscillations appear in the evolutions of Stokes parameters and their fluctuations. These oscillations c ollapse and revive intermittently. The polarization ellipse does not vary in the interaction with atoms but the degree of polarization will oscillate. Kerr medi um changes these oscillations distinctly.
Experimental research of laser-induced damage mechanism of the sol-gel SiO2 and IBSD SiO2 thin films
Authors: Chen Xi-Quan  , Zu Xiao-Tao  , Zheng Wan-Guo  , Jiang Xiao-Dong  , Lü Hai-Bing  , Ren Huan  , Zhang Yan-Zhen  , Liu Chun-Ming  ,   (1)电子科技大学应用物理系，成都  610054; (2)电子科技大学应用物理系，成都  610054;中物院激光聚变研究中心，绵阳  621900; (3)中物院激光聚变研究中心，绵阳  621900
Published: December 2020

This paper investigates the high-power laser-induced damage of two types of single-layer SiO2 thin films on K9 substrate, which are respectively deposited by IBSD technique and sol-gel technique, and have the same substrate parameters and the same film thickness. They were tested by surface thermal lensing technique to obtain the thermal absorbance and the dynamic response. The results show that the laser-initiated damage threshold of Sol-Gel SiO2 thin film is far higher than that of IBSD SiO2 thin film. And combined with threshold measurement and the microscopic observation, this paper well explains in detail the threshold difference between Sol-Gel SiO2 and IBSD SiO2 thin films.
Study on Z-scan characteristics for large optical nonlinear phase shift
Authors: Chen Shu-Qi  , Liu Zhi-Bo  , Zang Wei-Ping  , Tian Jian-Guo  , Zhou Wen-Yuan  , Zhang Chun-Ping  ,   南开大学物理科学学院光子学中心，天津  300071
Published: December 2020

Using Gaussian decomposition (GD) method, we studied the theory of Z-scan with large nonlinear phase shift induced by a pulsed laser. It has been verified that the GD method is still valid to deal with analysis of Z-scan measurements with large nonlinear phase shift. By comparing the peak-valley configuration of the Z-scan curves for large nonlinear phase shift induced by pulsed and CW laser, we found that some new peak-valley features of the Z-scan curves appear as the aperture size or light intensity increases in the case of large nonlinear phase shift. Meanwhile, we carried out the Z-scan experiments of pure CS2 to confirm the results of numerical simulation in the case of large nonlinear phase shift induced by a picosecond pulsed laser. The experimental results agree well with the theoretical. Our results have some significance to the measurement of Z-scan with large nonlinear phase shift induced by a pulsed laser.
Growth of ZnO microrod array films and their optical properties
Authors: Liu Hong-Xia  , Zhou Sheng-Ming  , Li Shu-Zhi  , Hang Yin  , Xu Jun  , Gu Shu-Lin  , Zhang Rong  ,   (1)南京大学物理系，南京  210093; (2)中国科学院上海光学精密机械研究所，上海  201800; (3)中国科学院上海光学精密机械研究所，上海  201800;中国科学院研究生院，北京  100049
Published: December 2020

A novel approach using low-cost and simple-equipment was successfully demonstrat ed on the growth of ZnO microrod array films. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) has characterized the microstructure of the samples . The results indicate that ZnO microrod array films are hexagonal, highly orien ted crystalline array films, grown along c-axis of ZnO on (0001) sapphire substr ates. The FWHM is about 1.8° for the (0004) rocking curve of the ZnO films. The photoluminescence spectra of ZnO array films show a strong and narrow peak at 395nm.
Study of the transport properties of self-assembled alkanethiol monolayer by conduction atomic force microscopy
Authors: Hu Hai-Long  , Zhang Kun  , Wang Zhen-Xing  , Wang Xiao-Ping  ,   (1)中国科学技术大学合肥微尺度物质科学国家实验室，合肥  230026; (2)中国科学技术大学合肥微尺度物质科学国家实验室，合肥  230026;中国科学技术大学物理系，合肥  230026
Published: December 2020

Self-assembled alkanethiol monolayers (SAMs) were prepared on the Au(111) substr ate. The behavior of the transport properties of SAMs under external load was in vestigated by the conduction atomic force microscopy. The current of SAM was fou nd to increase with the external load, and this property can be well characteriz ed by the Hertz model. It was also found that the conductance of SAM decreases e xponentially with the chain length of the alkanethiol molecules. The correspondi ng current decay constant β is demonstrated to decrease with the external load at first, and then becomes independent of the external load. Furthermore, the cu rrent of SAM with long chain molecules increases more apparently than that with short ones. These features all originate from the tunneling effect via nearby mo lecular chains for the charges.
Simulation of the proximity effect of electron beam lithography
Authors: Sun Xia  , You Si-Fang  , Xiao Pei  , Ding Ze-Jun  ,   中国科学技术大学，结构分析重点实验室，物理系，合肥  230026
Published: December 2020

Electron beam lithography has high sensitivity since it is free from limitation from diffraction effect. It will be the mostcommon technique of the next generation lithography to replace the conventional optical lithography. The proximity effect is the most important limitation of the sensitivity of lithography,which is simulated with Monte Carlo method in this paper.The influence on proximity effect of the shape and energy of electron beam and the material and depth of substrate is analyzed. The simulation results are compared with the experimental data and are found to fit well. It is found that, the proximity effect shown by Gaussian shaped electron beam is much larger than that by ideal electron beam, and lager atomic number, thicker substrate and lower energy of the electron beam will cause lager proximity effect independently.
Influence of weak magnetic field on growth morphology of Zn branched electrodeposits
Authors: Luo Cheng-Lin  , Yang Bing-Chu  , Rong Mao-Hua  ,   中南大学物理科学与技术学院,湖南长沙  410083
Published: December 2020

The influence of a weak magnetic field on the microstructure of the Zn electrode posits prepared in a thin concentric electrode cell is investigated. Mechanism o f the effect of the magnetohydrodynamic (MHD) flow on the morphological transiti on is proposed through experimental evidences. 1) In the early growth phase of a crystallite, the unbalanced force caused by the MHD flow on the crystallite, wh ich suspends in the electrolyte close to the previous branch, rotates its prefer ential growth orientation towards the downstream of the MHD flow; 2) A stable co ncentration profile is formed in the vicinity of the electrodeposits by the MHD flow. After the crystallite grows large enough to stick on its previous branch, and the concentration of the electrolyte is high enough for both the primary bra nch and its secondary branches, the single-crystalline dendrites will grow strai ght. But if the concentration of the electrolyte is small, the secondary branche s crowd to the side facing the upstream of the MHD flow and the primary branch i s forced to bend towards the downstream of the MHD flow. A spiral structure in t he branched electrodeposits grown in a magnetic field is formed by this mechanis m.
Simulation of effect of atomic process on poloidal CXRS measurement
Authors: Zhang Ting  , Ding Bo-Jiang  ,   (1)合肥工业大学理学院，合肥  230009; (2)中国科学院等离子体物理研究所，合肥  230031
Published: December 2020

With consideration of the effects of atomic process, a simple code modeling the correction to poloidal charge-exchange recombination spectroscopy (CXRS) measure ment is developed. The simulation results show that the measured poloidal veloci ty shift is overestimated in the ion diamagnetic drift direction and the apparen t ion temperature is underestimated because of the effects of energy-dependent e mission rate and finite lifetime of excited ions. This deviation will be more ob vious with the increase of temperature or magnetic field. The contributions from gradients of density and temperature are negligible compared to that from the a tomic process.
Studies on the full vibrational energies and dissociation energies for some states of alkali hydride molecules
Authors: Hu Shi-De  , Sun Wei-Guo  , Ren Wei-Yi  , Feng Hao  ,   (1)四川大学物理科学与技术学院,成都  610065; (2)四川大学原子与分子物理研究所,成都  610065; (3)西华师范大学理论物理研究所,南充  637002
Published: December 2020

The full vibrational energy spectra for the A1Σ+ states of alkali hydride diatomic molecules 6LiH, 7LiH, NaH, KH, RbH and CsH have been studied using algebraic method (AM), and the dissociation energies De of these molecules have also been studied using algebraic energy method (AEM). The results show that the AM produces accurate full vibrational energy spectra for these molecules for the first time so far as we know, and based on these AM spectra, the AEM can give correct molecular dissociation energies De for these systems.
Observation of Rydberg series of neutral barium by two-photon resonent nondegenerate four-wave mixing
Authors: Sun Jiang  , Zuo Zhan-Chun  , Guo Qing-Lin  , Wang Ying-Long  , Huai Su-Fang  , Wang Ying  , Fu Pan-Ming  ,   (1)河北大学物理科学与技术学院,保定  071002; (2)中国科学院物理研究所光物理实验室，北京  100080
Published: December 2020

We have applied two-photon resonant nondegenerate four-wave mixing (NFWM) with a resonant intermediate state to measure the energy levels of the Ba even-parity J=0 and J=2 series. Differing from other experiment techniques, our method is a pure optical technique. Instead of detecting electrons or ions, the signal here is a coherent light. Two-photon resonant NFWM is a Doppler-free spectroscopy when the incident laser beams have narrow bandwidths.
Interaction between charged particle and strained superlattice and chaotic behaviours of the system
Authors: Deng Cheng-Liang  , Shao Ming-Zhu  , Luo Shi-Yu  ,   东莞理工学院电子工程系, 东莞  523106
Published: December 2020

The effect on a particle motion of a deflecting channel is equated to modulation by a weak-periodic potential of similar shape as the channel. The motion equation of a particle is reduced to the nonlinear differential equation with a weak-periodic modulation by sine-squared potential. The critical conditions for the revelation of Smale horseshoe are analyzed using the Melnikov method. It is predicted that the chaotic behaviours may exit in the interaction of a particles between a crystal. Theory is provided to describe PME effects for the semicoductor superlattice.
Effect of Fe and Co on the electronic structure of (110) martensite twin boundary in Ni2MnGa alloy
Authors: Wan Jian-Feng  , Fei Yan-Qiong  , Wang Jian-Nong  ,   (1)上海交通大学材料科学与工程学院,上海  200030; (2)上海交通大学机器人研究所,上海  200030
Published: December 2020

Effect of iron and cobalt on the electronic structure of (110) martensite twin boundary in Ni2MnGa alloy have been investigated by using density functional theory (DFT), including twin boundary energy, segregation energy, magnetic moment, bond order and electronic density of states. The calculation results demonstrated that cobalt has a stronger doping effect on the twin interface than iron, and has less influence on the magnetic property of the twin boundary than the latter.
The influence of self-trapped exciton on luminescence of Pr3+ in aluminate under vacuum ultraviolet excitation
Authors: Wang Da-Wei  , Huang Shi-Hua  , You Fang-Tian  , Meng Chun-Xia  , Qi Shi-Qun  , Zhang Guo-Bin  , Fu Yi-Bing  , Xu Jian-Hua  , Huang Yan  ,   (1)北京交通大学光电子技术研究所，发光与光信息技术教育部重点实验室，北京  100044; (2)中国科学技术大学国家同步辐射实验室，合肥  230026; (3)中国科学院高能物理研究所同步辐射实验室，北京  100049
Published: December 2020

Spectroscopic properties of SrAl12O19:Pr3+ and Y3Al5O12:Pr3+ have been studied under vacuum ultraviolet excitation at 20, 77 and 300K. Self-trapped exciton(STE) luminescence in these aluminates were observed besides the characteristic emissions of Pr3+. Furthermore, the emission of STE became dominant as the concentration of activators and temperature decreased. The influence of STE on the luminescence of Pr3+ in aluminates was also emphasized.