bluuebunny/crossref_metadata_2025 huggingface dataset:
Dielectric study on relaxor-like phase transition of lanthanum doped bismuth layer-structured ferroelectrics
Authors: Hui Rong  , Zhu Jun  , Lu Wang-Ping  , Mao Xiang-Yu  , Qiang Feng  , Chen Xiao-Bing  ,   (1)扬州大学物理科学与技术学院,扬州 225002; (2)扬州大学物理科学与技术学院,扬州 225002;南京大学固体微结构物理实验室,南京 210008
Published: December 2020

Lanthanum doped bismuth layer-structured ferroelectrics and its intergrowth type, SrBi4-xLaxTi4O15, Sr2LaxBi4-xTi5O18, and (Bi,La)4Ti3O12-Sr(Bi,La)4Ti4O15, have been prepared by solid-state reaction method. The dielectric properties of those materials are measured. The results show that SrBi4-xLaxTi4O15 (x=1.0), Sr2LaxBi4-xTi5O18(x≥0.5)， (Bi,La)4Ti3O12-Sr(Bi,La)4Ti4O15(x=1.50) exhibit typical relaxational characteristics. The degree of diffuseness and relaxation increased with increasing La3+ content. The origin of relaxation is the microdomain induced by La3+ doing. The micromechanism corresponding to the transition between normal ferroelectrics and relaxors is explained as the transition from the macrodomain of normal ferroelectrics to the microdomain of relaxors.
Magnetic properties of Co-Pt-C grain films
Authors: Zheng Wu  , Wang Ai-Ling  , Jiang Hong-Wei  , Zhou Yun-Song  , Li Tong  ,   首都师范大学物理系，北京 100037
Published: December 2020

Co-Pt-C grain films with in plan magnetic anisotropy and large coercivity Hc were prepared by sputtering on Si substrates in multilayer form,with post-annealing in vacuum at 700℃ for 1?h. After annealing, Co-Pt particles trans form from amorphous to fcc CoPt3 and fct CoPt, and C remains in disorder state. Effects of Pt and C concentration on the magnetic properties of the films are studied. The maximum Hc is 430kA/m when the content of Pt is 70 vol% and the thickness of C layer is 0.4nm. The shoulder developed on the hysteresis loop is analyzed.
Calculations of magnetoelectric properties in three-phase ferroelectric and ferromagnetic particulate composites
Authors: Shi Zhan  , Nan Ce-Wen  ,   清华大学材料科学与工程系，新型陶瓷与精细工艺国家重点实验室，北京 100084
Published: December 2020

By the Green's function technique, we obtain the analytic expressions of the effective magnetoelectric property of composites and calculate the effective magnetoelectric properties of the threephase particulate composites made of rare earth-iron alloys, piezoelectric ceramics and polymer (Terfenol-D/PZT/PVDF). Our results show a strong influence of composite microstructure including the phase composition, aspect ratio of particles, orientation of polarization in PZT particles and applied bias field on the magnetoelectric properties. These numerical results provide guidelines for experimental design of the composites. After optimum design, the magnetoelectric voltage coefficient of these composites may reach as high as hundreds mV/A. As a new kind of magnetoelectric composite, such three-phase composites are expected to be a novel important kind of magnetoelectric materials because of their good magnetic-electrical response and easy fabrication.
Structural characteristics of HfO2 films grown by e-beam evaporation
Authors: Yan Zhi-Jun  , Wang Yin-Yue  , Xu Run  , Jiang Zui-Min  ,   (1)复旦大学应用表面物理国家重点实验室，上海 200433; (2)兰州大学物理系，兰州 730000
Published: December 2020

High k dielectric HfO2 films were deposited on p-type Si(100) substrates by e-beam evaporation. The composition of the films is determined to be stoichiometric. The structure changes from almost amorphous to polycrystalline after annealing. The films have very flat surface(rms roughness less than 0.3nm) and no voids appear even after high-temperature annealing, indicating a good thermal stability. The refractive index of HfO2 film is 2.09 (at 600?nm). The dielectric constant is 19. All the characteristics show that e-beam evaporation is a good method to deposit HfO2 thin films as dielectric.
Spectral properties of CdSSe nanocrystals in glass
Authors: Wang Yin-Shu  , Gao Xing-Guo  , Zhao Liang  , Wang Yan-Zhen  , Wang Ruo-Zhen  ,   北京师范大学物理系，北京 100875
Published: December 2020

CdS0.13Se0.87 nanocrystals of different sizes were grown by annealing glass contained Cd,Se and S at 650—800℃ for 4?h. The absorption spectra, photoluminescence spectra and electroabsorption spectra of the nanocrystals were measured. The energy of part of the electronic states was determined. Dependence of the optical properties of nanocrystals on their size was discussed. With the increase of nanocrystal size, the absorption, photoluminescence and eletroabsorption shifted red due to the weakening of quantum size Stark effects. The electroabsorption of small nanocrystals was due to the quantumconfined Stark effects whereas the electroabsorption line shape of larger nanocrystals was similar to that of bulk materials. With the increase of nanocrystal size, the electroabsor ption is enhanced. All nanocrystals have the third\|order optical susceptibility.
Synthesis structure observation and low field emission of CNx nanotubes
Authors: Ding Pei  , Chao Ming-Ju  , Liang Er-Jun  , Guo Xin-Yong  , Du Zu-Liang  ,   (1)河南大学特种功能材料实验室,开封 475001; (2)郑州大学物理工程学院，材料物理教育部重点实验室，郑州 450052; (3)郑州航空工业管理学院应用科学系，郑州 450015;郑州大学物理工程学院，材料物理教育部重点实验室，郑州 450052
Published: December 2020

Aligned CNx nanotubes were fabricated by pyrolyzing ethylenediamine on p-type Si(111) substrates deposited by Fe catalysts. Scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy were used to characterize the CNx nanotubes. The CNx nanotubes about 20μm in length and 50-100?nm in diameter have the “bamboo-like” structure and worse crystallinity. Field emission measurements of the CNx nanotubes indicated that 20μA/cm2 current densities were observed at an electric field of 1.4V/μm，and 1.280mA/cm2 were obtained at 2.54V/μm. No current saturation was found under higher electric field. The CNx nanotubes exhibit better field emission properties than carbon nanotubes and BCN nanotubes that have been grown under same experiment conditions only using different precursor solution. The emission mechanism of CNx nanotubes is also discussed based on their “bamboo-like” structures.
Study on the energy levels and electronic states of DNA molecules
Authors: Song Jun  , Chen Lei  , 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

The itinerancy of π electrons included in DNA molecules is related to their structures and configurations. The variation of the itinerant electrons will affect the band structure of this kind of soft material to some extent. In the frame work of the tight binding model, we calculated the band structure and the electronic density of states of a DNA chain. It was found that the band gap at the Fermi level depends sensitively upon the number of the itinerant electrons. The conductance of the DNA molecule in different orders of duplex pairs with possible combinations was discussed.
Simulation of translocation of long DNA chain through an entropic trapping channel
Authors: Xie Yong-Jun  , Shi Qin-Wei  , Wang Xiao-Ping  , Zhu Ping-Ping  , Yang Hai-Yang  , Zhang Xing-Yuan  ,   (1)中国科学技术大学高分子科学与工程系，合肥 230026; (2)中国科学技术大学理化中心，合肥 230026; (3)中国科学技术大学理化中心，合肥 230026;中国科学技术大学物理系，合肥 230026
Published: December 2020

Metropolis molecular dynamics simulation combined with bond-fluctuation method was employed to study the dynamic process of single DNA chain through an entropic trapping channel driven by an electric field. It was found that the single DNA chain experienced the processes such as random transfer, entropic trapping and fast transfer etc. The mobility of DNA increased with the increase of electric field and reached the conformation-independent mobility μ0 at a high electric field. In particular, a clear linear relationship between lnτ and 1/Eav (the reciprocal of electric field) could be seen. The simulation result was in agreement with the experimental result presented by Han et al qualitatively. In addition, the simulation provided a detailed dynamic process of the single DNA chain driven through an entropic trapping channel,which could not be observed in the experiment.
Viscoelastic wave equations of seismic multi-wave in fractured media
Authors: Du Qi-Zhen  , Yang Hui-Zhu  ,   (1)清华大学工程力学系，北京 100084; (2)石油大学（华东）地球资源与信息学院，东营 25706;石油大学中国石油天然气集团公司物探重点实验室，北京 102249
Published: December 2020

In the field of the oil exploration, the research is focused on the fracture detection in recent years. The difficulty is how to determine the orientation of the crack. To solve this problem, the relationship between the wave equations and the orientation of the crack should be determined. Unfortunately, the existing wave equations cannot completely reveal these relations. This paper studies the fractured media with arbitrary azimuthal angles. The convolution integral is solved incrementally, and then the corresponding time-domain wave equations are presented. The wave equations may be solved to model the wave propagation in the azimuthally anisotropic and viscoelastic media and to reveal the mechanisms of seismic multi-wave propagation in fractured media.
Mei symmetry of variable mass systems with unilateral holonomic constraints
Authors: Li Hong  , Fang Jian-Hui  ,   石油大学应用物理系，东营 257061
Published: December 2020

In this paper,the Mei symmetry of variable mass systems with unilatera l holonomic constraints is studied. The definition and criterion of the Mei symm etry of variable mass systems with unilateral holonomic constraints are given. T he structure equation and conserved quantity of the Mei symmetry are obtained. A n example is given to illustrate the application of the result.
Poincaré-Cartan integral invariant of a nonholonomic constrained generalized mechanical system
Authors: Li Ai-Min  , Zhang Ying  , Li Zi-Ping  ,   北京工业大学数理学院,北京 100022
Published: December 2020

Based on generalized Apell-Четаев constrained conditions and taking into a ccount the inherent higher-order nonholonomic constraints,the generalized Poincaré-Cartan integral invariant for a generalized mechanical system with higher- order subsidiary nonholonomic constraints is formulated. We can show that the ex istence of Poincaré-Cartan integral invariant for such a system is equivalent to the generalized canonical equation of a nonholonomic constrained generalized mechanical system.
Compacton solutions and floating compacton solutions of one type of nonlinear equations
Authors: Yin Jiu-Li  , Tian Li-Xin  ,   江苏大学非线性科学研究中心，镇江 212013
Published: December 2020

Study one type of nonlinear equations,namely generalized Camassa-Holm equation C(n):u\-t+ku\-x+β\-1uxxt+β\-2(un+1)x+β\-3u\-x(u\+n)xx+β\- 4u(u\+n)xxx=0.Obtain abundant exact solutions by four ansasz,particularly when k≠0,we obt ain compacton solutions;while whenk=0,we obtain floating compacton solution s.At last,we also study other forms of fully nonlinear generalized Camassa-Holm equation,and their compacton solutions are governed by nonlinear equations.
A simple fast method in finding the analytical solutions to a class of nonlinear partial differential equations
Authors: Xie Yuan-Xi  , Tang Jia-Shi  ,   湖南大学工程力学系，长沙 410082
Published: December 2020

By introducing,a new transformation and selecting appropriate trial functions ,nonlinear partial diff erential equations can be converted to algebraic equations,and their related coe f ficients can be easily determined by making use of the method of undetermined coefficients. Finally,the analytical solutions to a class of nonlinear partial di fferential equations are successfully derived. One can easily see that this meth od used herein is particularly simple.
A novel solution to singly quantized vortex in big N Bose-Einstein condensate
Authors: Xu Yan  , Jia Duo-Jie  , Li Xi-Guo  , Zuo Wei  , Li Fa-Shen  ,   (1)兰州大学磁学与磁性材料教育部重点实验室，兰州 730000; (2)兰州大学磁学与磁性材料教育部重点实验室，兰州 730000;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; (4)中国科学院近代物理研究所，兰州 730000;西北师范大学理论物理研究所,兰州 730030
Published: December 2020

An approximate analytical wave function is presented for an oblate ellipsoidal big N Bose-Einstein condensate(BEC) in a xi-symmetr ic harmonic traps. The relationship between the undetermined parameter C and the total particle number N,the aspect ratio λ of the BEC is obtained by varying t he energy functional. The parameter Cvaries extremely slowly versus N (orλ),and it becomes a fixed value 0.321646 when both Nand λare very large.
A five-dimensional cosmic branes solution in Einstein-Maxwell-dilaton gravity model
Authors: Yan Jun  , Tao Bi-You  ,   (1)成都77信箱工学院,成都 610066; (2)西南交通大学物理研究所,成都 610031
Published: December 2020

A new five-dimensional cosmic branes solution in Einstein-Maxwell-dilaton gravit y model is obtained in this paper,the physical meanings of this solution are ana lyzed and discussed.
The double noncommutative spacetime and the double complex symmetric gravitational theory
Authors: Wu Ya-Bo  , Shao Ying  , Dong Peng  ,   (1)大连理工大学物理系，大连 116023; (2)辽宁师范大学物理系，大连 116029
Published: December 2020

In this paper,the double complex symmetric gravitational theory is established and the concrete expression of the static spherically symmetric double complex metrics is derived by introducing the double complex symmetric metric tensors. In this theory the Moffat's results are extended,the hyperbolic complex symmetric gravitational theory is naturally obtained and the famous Schwarzchild solution is contained as the special case. Moreover,in the linearized weak field approximation the hyperbolic complex symmetric gravitational theory can automatically free from the potential problem of negative energy ghost states. Furthermore，the double complex symmetric gravitational action in the double noncommutative spacetime can be constructed by extending the double complex coordinates to the double noncommutative relation satisfied and doubling the Moyal star product.
Effects of organic/organic interface on recombination efficiency in double-layer organic diodes
Authors: Xu Xue-Mei  , Peng Jing-Cui  , Li Hong-Jian  , Qu Shu  , Zhao Chu-Jun  , Luo Xiao-Hua  ,   (1)湖南大学应用物理系,长沙 410082; (2)湖南大学应用物理系,长沙 410082;中南大学物理科学与技术学院,长沙 410083
Published: December 2020

A disorder hopping model for carriers recombination at organic/organic interface (OOI) in double-layer organic light emitting diodes (OLEDs) was presented. According to the structure of an OOI as well as spatial and energetic disorder of hopping states, it was more reasonable to use the disorder hopping model than to use the Fowler-Nordheim formalism. It was shown that the carriers hopping distance, the effective barrier height and the electric field contribution had heavy effects on recombination efficiency. Firstly, when the applied voltage was less than 19.5V (in double-layer OLEDs ITO/α-NPD/Alq3/Al), recombination efficiency increased with the increase of hopping distance, while the applied voltage was larger than 19.5V, it decreased with the increase of hopping distance; secondly, it also increased with the increase of effective barrier height at OOI; Finally, it increased with the increase of differences of electric field at OOI, while it decreased when the value of differences of electric field reached 24×105V/cm. These results were consistent with some experiments.
Determining the controllable conditions for time-delayed feedback chaos control
Authors: Zhang Xiao-Ming  , Peng Jian-Hua  , Chen Guan-Rong  ,   (1)深圳大学理学院，深圳 518060;东北师范大学物理系，长春 130024; (2)香港城市大学电子工程系，香港
Published: December 2020

Based on Hopf bifurcation theory and methods in time-delayed systems, we ana lytically determine some general conditions of time-delayed feedback control of three-dimensional autonomous chaotic systems. With this method, a criterion for the stability of periodic solution under control and for the direction of Hopf b ifurcation is derived theoretically studied. Applying the method to the control of some three-dimensional autonomous chaotic systems, we can analytically find the cont rollable parameter in this region. Choosing parameters in it, we can successfull y stabilize chaotic orbits to periodic states.
Study on phase-space reconstruction of chaotic signal based on wavelet transform
Authors: You Rong-Yi  , Chen Zhong  , Xu Shen-Chu  , Wu Bo-Xi  ,   (1)集美大学物理系，厦门 361021; (2)厦门大学物理系，厦门 361005
Published: December 2020

Using the methods of the wavelet transform and the nonlinear dynamics, the b ehavior of chaotic signals in phase space is studied. It is indicated that, in p hase space reconstruction, the wavelet transform of chaotic time series is essen tia lly a projection of strange attractor on the axis of the space that filter vect ors opened, which in correspondance with the method of phase space reconstructio n proposed by Packard et al. The experimental results show that, after d oing wavelet transform, the architecture of attractor trajectory is similar to t he original one, and the nonlinear invariants such as correlation dimension and Kolmogorov entropy are reserved. These results show that wavelet transform is ef fective for studying chaotic signal.
Superharmonic resonance bifurcation control of parametrically excited system based on state feedback strategy
Authors: Fu Wen-Bin  , Tang Jia-Shi  ,   湖南大学工程力学系,长沙\ 410082
Published: December 2020

A nonlinear parametric feedback control is propo sed to modify the steady-state resonance responses, thus to reduce the amplitude of the response and to eliminate the saddle-node bifurcations that take place i n the resonance responses. The nonlinear gain of the feedback control is determi ned by analyzing the bifurcation function associated with the corresponding freq uency-response equation and the Jacobian matrix. It is shown by illustrative exa mples that the proposed nonlinear feedback is effective for controlling superhar monic resonance responses.
The study of a cellular automaton traffic flow model with mixed different-maximum-speed vehicles on single lane
Authors: Kuang Hua  , Kong Ling-Jiang  , Liu Mu-Ren  ,   广西师范大学物理与信息工程学院，桂林\ 541004
Published: December 2020

Based on the NS models of traffic flow, a cellular automaton traffic mo del with different-maximum-speed vehicles mixed on single lane is proposed. We p resent the fundamental diagrams of traffic flow under different parameters by us ing computer numerical simulation. The model's traffic flow characters are prese nted and analyzed.
A study on multi-speed cellular automata model of traffic flow of main-road with two-lane under the traffic light control
Authors: Peng Lin  , Tan Hui-Li  , Wu Da-Yan  , Liu Mu-Ren  , Kong Ling-Jiang  ,   广西师范大学物理与信息工程学院，桂林 541004
Published: December 2020

A multi-speed and two-lane cellular automata model of traffic flow was proposed to simulate the main road traffic in city under the open boundary condi tions. By considering many real factors, the effects on traffic flow and velocit y of the main-road, produced by the bus stop and the time switched between the green light and the red light, have been analyzed. The result can reflect the re al traffic flow of the main-road in city under the control of the traffic lights .
Study on the corner effect in new grooved-gate nMOSFET
Authors: Tong Jian-Nong  , Zou Xue-Cheng  , Shen Xu-Bang  ,   (1)华中科技大学图像所IC设计中心，武汉 430073; (2)华中科技大学图像所IC设计中心，武汉 430073;华中科技大学电子科学与技术系,武汉 430073
Published: December 2020

The function and influence of the corner effect in groovedgate MOSFET is simulated using classical twodimensional device simulator PISCESⅡ. The electric field of the channel in groovedgate metalorganic semiconductor field effect transistor(MOSFET) and impact on the threshold and hot carrier effect are studied. The corner effect is very favorable to suppressing short channel effects and hot carrier effects. The impact of corner effect on groovedgate MOSFET is changed with the change of the corner, and is the largest at about 45°. Therefore， the groovedgate MOSFET has a very great application prospect in deep submicro device architecture.
Thermoluminescence and optical stimulated luminescence of undoped α-Al2O3 single crystal
Authors: Zhang Chun-Xiang  , Lin Li-Bin  , P. L. Leung  , Tang Qiang  , Mike Li  , Luo Da-Ling  ,   (1)四川大学辐射物理及技术国家教育部重点实验室,成都 610064; (2)香港城市大学物理及材料科学系,香港; (3)中山大学物理学系,广州 510275
Published: December 2020

The thermoluminescence (TL) glow curves, three-dimensional emission spectra and optical-stimulated luminescence (OSL) of undoped α-Al2O3 single crystals were investigated. Two glow peaks at 76 and 207 ℃ are observed after β-rays irradiation of Sr-90 source. After γ-rays irradiation the emission spectra of α-Al2O3 show that the emission peak of 416 nm wavelength at about 207 ℃ is related to the relaxation of an electron from the excited 3P state to the ground state 1S of the F center. The first order kinetic equation can fit the 207 ℃ glow peaks well. Besides, the measured shape and peak temperature of the glow curves are almost not related to the absorbed dose. The dose response of the peak heights is linear-sublinear. Therefore, it is concluded that the glow peak at 207 ℃ at 416 nm can be described by the first-order kinetics. The dose responses of OSL and TL are linear-sublinear.
Magnetic Salisbury screen and its high-frequency response
Authors: Wu Rui-Xin  , Chen Ping  ,   南京大学电子科学与工程系，南京 210093
Published: December 2020

We have studied the possibility of constructing magnetic Salisbury screen, and the frequency response of reflectivity of the screen in microwave frequency range. We have found that magnetic Salisbury screen has a lower reflectivity when magnetic susceptibility satisfies χ″χ′. If the frequency response of magnetic susceptibility is in the relax type of domain wall resonance, we could make filmtype Salisbury screen, in which the thickness of the screen may be in the order of micrometer or even submicrometer. The reflectivity of the screen depends on the characteristic impedance zr of the magnetic film that is determined by ferromagnetic resonant frequency and susceptibility under a static field. The frequency response of reflectivity shows that the magnetic film Salisburyscreen has a broadband frequency range for absorbing microwaves well.
Study of relational nuclear databases and online services
Authors: Fan Tie-Shuan  , Guo Zhi-Yu  , Liu Wen-Long  , Ye Wei-Guo  , Feng Yu-Qing  , Song Xiang-Xiang  , Huang Gang  , Hong Ying-Jue  , Liu Ting-Jin  , Chen Jin-Xiang  , Tang Guo-You  , Shi Zhao-Min  , Liu Chi  , Huang Xiao-Long  , Chen Jia-Er  ,   (1)北京大学重离子物理研究所，重离子物理教育部重点实验室，北京 100871; (2)北京大学重离子物理研究所，重离子物理教育部重点实验室，北京 100871;中国核数据中心，中国原子能科学研究院，北京 102413; (3)中国核数据中心，中国原子能科学研究院，北京 102413
Published: December 2020

A relational nuclear database management and webbased services software system has been developed. Its objective is to allow users to access numerical and graphical representation of nuclear data and to easily reconstruct nuclear data in original standardized formats from the relational databases. It presents 9 relational nuclear libraries: 5 ENDF format neutron reaction databases (BROND, CENDL, ENDF, JEF and JENDL), the ENSDF database, the EXFOR database, the IAEA Photonuclear Data Library and the charged particle reaction data from the FENDL database. The computer programs providing support for database management and data retrievals are based on the Linux implementation of PHP and the MySQL software,and are platformindependent. The first version of this software was officially released in September 2001.
Study on coherent phase modulation of coherent population trapping in V-type atomic system
Authors: Wang Li-Qiang  , Li Yong-Fang  , Cao Dong-Mei  , Bi Dong-Yan  , Zhang Chong-Jun  , Cheng Yan-Chun  ,   (1)陕西师范大学物理学与信息技术学院，西安 710062; (2)陕西师范大学物理学与信息技术学院，西安 710062;延安大学物理学院，延安 716000; (3)武警工程学院基础部，西安 710068
Published: December 2020

It is realized that coherent population trapping (CPT) and electromagnetically induced transparency (EIT) are modulated by coherent phase modulation in a Vtype atomic system excited by delaytime laser pulses; the modulation period can reach femtosecond order if the proper energy levels are selected. The relation between the delaytime laser pulse and the population of each energy level are investigated by the numerical and analytical solutions. The characteristic and regularity of population modulated by laser fields phase are obtained as well. Utilizing this mechanism, one can get the quantum switch,of which the modulation period can get to femtosecond order.
Study of the electron transfer in Xeq+-He collisions
Authors: Cao Zhu-Rong  , Cai Xiao-Hong  , Yu De-Yang  , Yang Wei  , Lu Rong-Chun  , Shao Cao-Jie  , Chen Xi-Meng  ,   (1)兰州大学物理科学与技术学院，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
Published: December 2020

The cross section ratios of the double to single electron transfer of helium target induced by Xeq+(q=15,17,19,21,23) ions are measured by means of the position sensitive and timeofflight techniques. By considering an onestep transfer mechanism, we modify the extended classical overbarrier model. It is found that the calculated single and double electrontransfer cross sections using the modified model show excellent agreement with the experimental data of Andersson et al. and Selberg et al, and improves the agreement with the present measured double to single electrontransfer ratio considerably.
The vectorial properties of paraxial beams propagating in a uniaxial crystal
Authors: Luo Hai-Lu  , Hu Wei  , Yi Xu-Nong  , Zhu Jing  ,   华南师范大学传输光学实验室，广州 510631
Published: December 2020

The vectorial properties of paraxial beams propagating perpendicular to the optical axis of a uniaxially anisotropic crystal are investigated. By relying on a suitable planewave angular spectrum representation of the electromagnetic field, we obtain the analytical expressions of optical fields. The longitudinal component is expressible in terms of the first correction of the transverse field. Moreover, the extraordinary beams can induce ordinary beams in terms of the second correction of the transverse field.
Phase-contrast imaging with microfocus x-ray source
Authors: Chen Min  , Xiao Ti-Qiao  , Luo Yu-Yu  , Liu Li-Xiang  , Wei Xun  , Du Guo-Hao  , Xu Hong-Jie  ,   中国科学院上海应用物理研究所，上海 201800
Published: December 2020

We report the experimental results of the inline phasecontrast imaging with a microfocus xray source. The minimized focused spot size of the xray source is about 05μm. According to the optical transfer function of the microfocus xray source, the effects of the size of the xray source, the coherent length of xray on the imaging resolution are discussed. The phasecontrast images of the fresh biomaterials are obtained with 10μm resolution. Compared with the absorptioncontrast image of the sample, the finestructure of the fresh biomaterials can be observed distinctly in the phasecontrast image.
Light coupling in Y-cut doped lithium niobate crystals
Authors: Gao Yuan-Mei  , Liu Si-Min  , Guo Ru  , Huang Chun-Fu  , Wang Da-Yun  ,   南开大学物理学院，天津 300071
Published: December 2020

We experimentally study the light coupling behaviors between the transmittinglight and reflected light in ycut lithium niobate crystals. When the epolarized incident light is launched into the crystals along +y axis and -y axis, respectively, we find that the time behaviors of the reflectivity and transmissivity are almost identical for both cases, respectively. Whereas when the opolarized incident light is launched into the crystals along +y axis and -y axis, respectively, the time behaviors of the reflectivity and transmissivity for both cases are obviously different. We investigate the physics mechanism of these phenomena preliminarily.
Experimental study of enhancement of the light-modulated absorption of bacteriorhodopsin-D96N films
Authors: Yang Wen-Zheng  , Hou Xun  , Chen Feng  , Yang Qing  ,   (1)西安交通大学电子科学与技术系,西安 710049; (2)中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室,西安 710068; (3)中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室,西安 710068;西安交通大学电子科学与技术系,西安 710049
Published: December 2020

In this paper, the light-modulated characteristics of the gene-variant bacteriorhodopsin-D96N molecule film are studied by spectrum response experiment. The absorption enhancement phenomena of BRD96N films at 550—600nm modulated light wavelength are gained, and there are different absorption changes at different monochromatic wavelengths. Using curve-fitting method, it is found that the process of the absorption change includes fast and slow responses with time constants of 30 s and 5 min respectively. Applying the relations between the absorption change and gray-scale image to the write-readout image experiment, the reverse image phenomena in a wavelength range of 550—600nm are analyzed.
Solution of radial equation of Kepler’s problem by pseudo-angular-momentum method and normalization of eigenstate and coherent state
Authors: Li Wen-Bo  , Li Ke-Xuan  ,   北京交通大学物理系，北京 100044
Published: December 2020

By using the pseudoangularmomentum method, the radial equation for bound state of Kepler's problem is solved and the analytic expression for eigenstate is derived. The result shows that the normalization of eigenfunction that should be done carefully is quite peculiar. The corresponding coherent state is also discussed.
Electromagnetically induced transparency in a four-level atomic system driven by three coupled fields
Authors: Liu Zheng-Dong  , Wu Qiang  ,   (1)南昌大学（北区）近代物理研究所，南昌 330047; (2)浙江工业大学应用物理系，杭州 310032
Published: December 2020

We study the spontaneous emission in a fourlevel atomic system driven by three coupled fields. We have demonstrated the existence of electromagnetically induced transparency (EIT) with a set of suitable parameters, and we find that the light levels of the drive fields are as weak as that of the spontaneous emission with the EIT.
Diffraction-induced spectral switches of spherically aberrated polychromatic Gaussian beams
Authors: Zhao Guang-Pu  , Lü Bai-Da  ,   (1)四川大学激光物理与化学研究所，成都 610064; (2)宜宾学院光电信息研究所，宜宾 644007;四川大学激光物理与化学研究所，成都 610064
Published: December 2020

Starting from the propagation law of the crossspectral density function, an analytical expression for the onaxis spectrum of spherically aberrated pol y chromatic Gaussian beams diffracted at an aperture is derived, the aberration f ree result is obtained as a special case treated in the paper. Detailed numerica l calculations and physical analysis are presented. It is shown that the onaxis spectrum in the near field may be redshifted and blueshifted in co mparison wi th the aberrationfree case, and the spectral switch may also take place. In pa r ticular, the influence of spherical aberration on the behavior of spectral swit ches is illustrated.
Optimal designs for high-power vertical cavity surface emitting lasers
Authors: Li Hui-Qing  , Zhang Jie  , Cui Da-Fu  , Xu Zu-Yan  , Ning Yong-Qiang  , Yan Chang-Ling  , Qin Li  , Liu Yun  , Wang Li-Jun  , Cao Jian-Lin  ,   (1)中国科学院长春光学精密机械与物理研究所，激发态物理重点实验室，长春  130033; (2)中国科学院物理研究所，光物理重点实验室，北京 100080
Published: December 2020

Vertical cavity surface emitting lasers (VCSEL's) lase in a single longitudin al mode, have a circularly symmetric output beam that can be very tightly focused, offer extremely high coupling efficiencies into optical fiber, and can be mas s produced in two-dimensional arrays relative to the conventional edge-emitting semi conductor laser. To obtain a high optical output power, besides enlarging of VCS EL's lasing area, the key points are proper number of quantum wells, homogeneous dist ribution of current density in the active layer and good thermal control. The dependenc e of VCSEL's performance on the number of quantum wells, the active diameter, th e thermal conductivity and the electric resistance of the material; and the dist ance between electri cal contacts are investigated. By optimizing the design parameters for a 980 nm In0.2Ga0.8As/GaAs VCSEL, a maximum continuous wave (cw) output power of 1.95 W at room temperature is obtained, which to our knowledge is the highest cw output power of any single VCSEL so far.
Interaction potential between spatial optical solitons based on holographic focusing mechanism
Authors: Jiang Jin-Huan  , Li Zi-Ping  ,   (北京工业大学应用数理学院,北京 100022)
Published: December 2020

The interactions between spatial optical solitons based on holographic focusing mechanism propagating in opposite directions are studied by means of variational method. It is shown that the coherent interactions are insensitive to relative phase between two beams in some cases, and this is just the result of the recent paper.
Effect of the pump light on the beam quality of the diode pumped laser
Authors: Wang Shi-Yu  , Guo Zhen  , Fu Jun-Mei  , Cai De-Fang  , Wen Jian-Guo  , Tang Ying-De  ,   (1)西安电子科技大学技术物理学院,西安 710071; (2)西安交通大学微波研究所,西安 710048; (3)西安交通大学微波研究所,西安 710048;西安电子科技大学技术物理学院,西安 710071
Published: December 2020

Effect of the pump light on the quality of diode pumped laser (DPL) has been di scussed. Based on the end pump system, the equation of the laser field has been studied, which shows that the distribution of the laser gain can affect the la ser mode and make the base mode of the laser to drift off from the Gauss distrib ution . A factor is proposed to estimate the scale of the affection, which is called a f fection factor of pump light. Calculations on the end pump laser prove that the factor is practical and convenient. Study on the Qswitched laser show that the field distribution of the pulse is also affected by the distribution of the pump beam. The rising edge of the pulse usually evolves from far to near gauss distribution. The phenomenon is called as the field evolution of the pulse risin g edge.
Measurement of spectral phase of femotosecond laser pulse using SPIDER technique
Authors: Wang Peng  , Wang Zhao-Hua  , Wei Zhi-Yi  , Zheng Jia-An  , Sun Jing-Hua  , Zhang Jie  ,   中国科学院物理研究所光物理重点实验室,北京 100080
Published: December 2020

We present an experimental set up and the calculation approach for the measureme n t of the spectral phase of femtosecond laser pulse by using a spectral phase int erferometry for direct electric reconstruction (SPIDER) technique in this paper, the method for determining crucial parameters as Ωand τwas given. W ith the femtosecond laser pulse from the Ti:sapphire laser, we obtained the phase of the laser spectrum by using the SPIDER, the temporal profile of the original laser pulse was deduced based on the result. It reveals the FWHM width is 107fs, which is in good agreement with the result measured directly by using an autocorrelat or.
The fabrication and properties of InAs/GaAs columnal islands
Authors: Zhu Tian-Wei  , Xu Bo  , He Jun  , Zhao Feng-Ai  , Zhang Chun-Ling  , Xie Er-Qing  , Liu Feng-Qi  , Wang Zhan-Guo  ,   (1)兰州大学物理科学与技术学院,兰州 730000; (2)中国科学院半导体研究所半导体材料科学重点实验室,北京 100083; (3)中国科学院半导体研究所半导体材料科学重点实验室,北京 100083;兰州大学物理科学与技术学院,兰州 730000
Published: December 2020

A columnal islands system, which was composed of three layers of self-assembled InAs/GaAs quantum dots (QDs), has been fabricated by solid-source molecular beam epitaxy (MBE) through S-K mode on a (100) semi-insulating GaAs substrate. The effects of the thickness of GaAs space layer, the growth interruption time and the amount of InAs deposition on the emission wavelength of columnal islands were presented. The image of atomic force microscopy (AFM) indicated the columnal islands with high uniformity in size and shape. At room temperature, the emission wavelength of columnal islands with different effective heights was achieved 1.32 and 1.4μm; however, the emission wavelength of single-layer QDs with normal height was just 1.1μm. It provides a useful and intuitive approach to artificially control the emission wavelength of a QD material system.
Response characteristic of femtosecond LT-GaAs photoconductive switches at different voltage bias
Authors: Deng Li  , Liu Ye-Xin  , Shou Qian  , Wu Tian-Hong  , Lai Tian-Shu  , Wen Jin-Hui  , Lin Wei-Zhu  ,   中山大学光电子材料与技术国家重点实验室/物理系,广州 510275
Published: December 2020

The response characteristic of a LTGaAs photoconductive switch formed in a cop lanar waveguide at different voltage bias is studied with photocurrent autocorre lation measurement technique. The experimental results show that the switching t ime increases from ～200fs to ～750fs, when the bias voltage ascends from 0.5×104 to 9.5×104 V/cm. This phenomenon is attributed to the increase of carr ier capture time arising from the potential barrier lowering (FrenkelPoole eff ect) and the fieldenhanced thermal ionization.
Existence curves of asymmetric photorefractive holographic spatial optical solitons
Authors: Liu Jin-Song  ,   华中科技大学激光技术国家重点实验室,武汉 430074
Published: December 2020

It has been proved that there exist asymmetric holographic spatial optical solit on pairs in biased photorefractive crystals. The two solitons from such a pair h ave equal width and unequal amplitudes. The soliton existence curves of such sol iton pairs are given and three regions of different behaviors exist in these curves. That is, for a given value of bias field, the width of holographic solitons depends strongly on the ratio of the total peak input intensity of the two solitons from a pair to the intensity of the background light when the ratio is small or large enough, whereas it remains relatively constant in a middle r egion. The extent of the middle region for the asymmetric case is smaller than t hat for the symmetric case.
Interaction between optical spatial solitons in nonlocal Kerr media
Authors: Xie Yi-Qun  , Guo Qi  ,   华南师范大学信息光电子科技学院传输光学实验室,广州 510631
Published: December 2020

In this paper, it is discussed that a pair of optical beams copropagates in no nlocal Kerr media, which is governed by the nonlocal nonlinear Schr?dinger equa tion (NNLSE). A new approximate linear model to the NNLSE is presented for the s trong nonlocal Kerr media with arbitrary response functions. An analytical solut ion in Gaussian form to the model is obtained. It is shown that the phase of eac h of the two beams is depended on the total input power. As a concrete example, th e interaction of two beams with the intensity of one of the beams much stronger than that of the other is discussed. It is found that the phase shift of the wea ker (probe) beam is very large within rather short propagating distance in the c ase of soliton, which can be controlled by modulating the input power of the str onger (pump) beam.
Stability of photovotaic spatial soliton with two-wavelength components
Authors: Ouyang Shi-Gen  , Jiang De-Sheng  , She Wei-Long  ,   中山大学光电材料与技术国家重点实验室,广州 510275
Published: December 2020

An approximate method is presented to calculate the full width at half maximum(F WHM) of photovoltaic(PV) spatial solitons(PVSSs) with twowavelengths component . An advanced numerical analysis i ndicates that two coaxial hyperbolic secant beams, provided that they satisfy th e functional relations of FWHM with amplitudes of this type of PVSS, will be ver y close to solitons when they propagate in PV crystals. Besides, this type of PV S S tends to be stable against small axial perturbations and small refractive inde x perturbations due to variations of temperature of the crystal. However, if the pro files of intensity of two coaxial signal beams with different wavelengths diff e r mildly from those of PVSS, the two beams will tend to experience cycles of co mpression and expansion; and if the profiles of intensity of the signal beams di ffer significantly from those of PVSS, these two signal beams will diffuse endle ssly.
Dark-bright photovoltaic soliton pair with two-wavelength components
Authors: Quyang Shi-Gen  , She Wei-Long  ,   中山大学光电材料与技术国家重点实验室,广州 510275
Published: December 2020

We present a scheme to realize coupled dark-bright photovoltaic spatial-soliton pairs with two-wavelength components. With the propagating beam method we numeri cally study the spatial dynamic properties of these coupled solitons, finding th e possibility to use such coupled solitons in all-optical beam switching.
Propagation of optical pulses through one-dimensional photonic crystals with a dispersive and gain defect layer
Authors: Yu Tian-Bao  , Liu Nian-Hua  ,   南昌大学物理系,南昌 330047
Published: December 2020

The propagation of a pulse through onedimensional photonic crystals with a dispersive and gain defect layer is discussed. The dispersion and gain of the defect layer is described by Lorentz oscillator model. It is found that the pulse pea k exhibits subluminal and superluminal behaviors with varying strength of the os cillator. The Poynting vector and energy velocity can be negative, but the latte r is never faster than the vacuum light speed c. The advance or delay of the pulse peak is a result of the coherent superposition of all Fourier components which experienced different phase shift and different amplification in the medium.
Synthesis and optical properties of durable opal photonic crystals with high crystalline quality
Authors: Wang Jing  , Yuan Chun-Wei  , Huang Zhong-Bing  , Tang Fang-Qiong  ,   (1)分子与生物分子电子学教育部重点实验室（东南大学）,南京 210096; (2)分子与生物分子电子学教育部重点实验室（东南大学）,南京 210096;大连水产学院理学院,大连 116023; (3)中国科学院理化技术研究所,北京 100101
Published: December 2020

Polystyrene (PS) colloidal crystal multilayers with high crystalline quality are fabricated quickly from aqueous colloidal solutions by the vertical deposition method at certain temperature and humidity. Optical properties, which are determined by the photonic band structure, are discussed by means of light transmission and reflection measurements. By scanning electron microscopy (SEM), the morphology of the samples is characterized and the ordered close package of the spherical colloids in planes parallel to the substrate surface is illustrated. Furthermore, facecenteredcubic (fcc) phase is proved by transmission ele ctron microscope (TEM). To avoid friability and redispersal, the colloidal c rystals multilayers are dried slowed and sintered at 105℃ for 6 hours to enlarg ement of the contact section between nearestneighbor PS spheres. Experiments h ave proved the efficiency and practicability of the method.
Raman scattering of ethanol solvent in a photonic crystal with a variational lattice constant
Authors: Liu Xiao-Dong  , Ni Pei-Gen  , Cheng Bing-Ying  , Zhang Dao-Zhong  ,   (1)中国科学院物理研究所光物理实验室，北京 100080; (2)中国科学院物理研究所光物理实验室，北京 100080;大连民族学院光电技术研究所和应用数理系，大连 116600
Published: December 2020

A silica colloidal photonic crystal in ethanol solution, whose lattice constant varies with the height of the crystal, was prepared. The Raman intensities of th e ethanol solution induced by a picosecond intense laser were measured at differ ent heights, and two phenomena were found: (1) although the frequency of Raman s ignals generated within the photonic crystal is equal to that of the photonic ps eudogap of the photonic crystal, the Raman intensity attenuation measured is not reduced to the extent of that in the conventional transmission experiment; (2) although the transmission of an incident beam with the wavelength of the Raman s ignal is strongly dependent on the height of crystal, the intensity of th e Raman scattering generated within the silicaethanol colloidal photonic crystal does n ot change with the height, i.e. it is insensitive to the pseudogap. These anti i ntuitive phenomena may be directly interpreted using the fact that the propagati on mechanism of the monodirectional incidental laser is intrinsically different from that of the Raman signals from inner light sources inside a photonic crysta l, and the Raman signals scattered by defects deep inside the crystal and genera ted in the surface layer contribute largely to the measured intensities.
The influence of the magnetic field magnetron under the substrate on the sputtering glow and film thickness gradient
Authors: Zhao Xin-Min  , Di Guo-Qing  ,   苏州大学物理系, 苏州 215006
Published: December 2020

A new magnetron sputtering method is tried by placing a magnet under the substrate during sputtering. Compared with the case without applied magnetic filed, we have found that the glow appearances and the film thickness distribution are changed greatly. The aspect of the glow above the substrate face vary with the magnet diameter. We make the glow appearances mechanism clear using the simulation of the magnetic field, and interpret the film thickness distribution as a result of the motion of the particles sputtered from the target in the special-distributed magnetic field.
Study on dispersion characteristics of a tilted birefringent filter
Authors: Jia Ya-Qing  , Zhu Xiao-Nong  ,   南开大学现代光学研究所,光电信息技术科学教育部重点实验室,天津 300071
Published: December 2020

We present theoretical investigations of the second and the thirdorder group d elay dispersion caused by a tilted birefringent filter (TBF). The expression for the group delay of TBF is deduced and the corresponding dispersions are calcula ted. The influence of the parameters such as the thickness, the tilting angle an d the rotation angle of the birefringent plate on dispersions are discussed. Com parison between the dispersion characteristics of a GiresTournois interferomet er (GTI) and those of TBF is also present.
Study of pulse transmission properties in nonlinear optical loop mirror
Authors: Tan Bin  , Li Zhi-Yong  , Li Shi-Chen  ,   天津大学精密仪器与光电子工程学院,教育部光电信息技术科学重点实验室,天津 30 0072
Published: December 2020

We have studied the pulse transmission properties in a nonlinear optical loop mi rror (NOLM) with abnormal despersion and obtained the firs t maximum of transmission, the compression ratio and related soliton order at th e first maximum as functions of nomarlized loop length. With the comparison of t ransmission and compression properties of both transmission limited and chirped pulses in long and short loop loop length NOLMs, we conclude that long NLOM is f it for pulse shaping, while short NOLM is fit for pulse compression.
A novel design methodology for superstructure fiber Bragg grating comb-filter
Authors: Cao Hui  , Sun Jun-Qiang  , Zhang Xin-Liang  , Xiao Ling-Yan  , Huang De-Xiu  ,   (1)华中科技大学光电子工程系,武汉 430074; (2)华中科技大学光电子工程系,武汉 430074;佛山科学技术学院物理学系,佛山 528000; (3)武汉光讯科技有限责任公司,武汉 430074
Published: December 2020

A novel superstructure fiber Bragg grating (SFBG) combfilter for multiwavele ngth laser is proposed. This SFBG is characterized by its singlegrating struct ure, both refractive index modulation and local chirp abundant in variation, sym metri cal reflection peaks, narrow bandwidth and standard channel spacing. Based on layerpeeling inverse scattering technique, adopting independent channelbycha nnel apodizingwindowing method rather than integral apodizingwindowing proce dure, the desired SFBG is figured out successfully. The fa brication techniques for this SFBG are discussed as well. Reflection spectrum, group time delay and group time delay ripple are analyzed by the method of transf ormation matrix. The results show that this SFBG satisfied all requirements of designing target. In DWDM optical fiber telecommunication systems, this novel SFB G is a promising candidate for the perfect high performance combfilter used in multiwavelength laser.
Slow waves propagation in BISQ poroelastic model
Authors: Cui Zhi-Wen  , Wang Ke-Xie  , Cao Zheng-Liang  , Hu Heng-Shan  ,   吉林大学物理学院,长春 130023
Published: December 2020

The slow compressional wave (P2wave) in porous media based on BISQ model is investigated. The lowfrequency approximate expression for velocity and attenua t ion of P2wave is presented. Compared with Biot model, BISQ model predicts tha t the attenuation of P2 waves is very large at low frequency and decreases with increasing characteristic squirt flow length (R), the velocity lowfrequency limit is not zero and decreases with increasingR, variation of the ratio of pore fluiddisplacement to bulkdisplacement is similar to that of attenuation and its phase is diffe rent from that of Biot model. The seepage flow induced by P2 wave at the fluidporous media interface is larger than that of Biot model. For the sake of contrast, the p roperties of the fast compressional wave are also presented. Two conclusions are induced from the BISQ model: there is no squirt mechanism in inviscid fluid-satura ted porous media and there is no “dynamic compatibility” phenomenon in viscid fluid-saturated porous media.
Limitation for the energy spectrum analysis for the understanding of the turbulent cascade
Authors: Meng Qing-Guo  , Cai Qing-Dong  , Li Cun-Biao  ,   (1)北京大学湍流与复杂系统国家重点实验室，北京 100871; (2)国家自然科学基金委员会数理科学部，北京 100085
Published: December 2020

Simple examples were applied to show that the “cascade" and “inverse cascade” presented in an energy spectrum even without real physical cascade processes. T he misleading comprehension should appear if energy spectrum was considered as a un ique evidence of the energy cascade in turbulence.