bluuebunny/crossref_metadata_2025 huggingface dataset:
Second-order Stokes wave solutions for intefacial waves in three-layer stratified fluid with background current
Authors: Pang Jing  , Chen Xiao-Gang  , Song Jin-Bao  ,   (1)内蒙古工业大学理学院,呼和浩特 010051; (2)内蒙古工业大学理学院,呼和浩特 010051;中国科学院海洋研究所,青岛 266071; (3)中国科学院海洋研究所,青岛 266071
Published: December 2020

In this paper, interfacial waves in three-layer stratified fluid with background current are investigated using a perturbation method, and the second-order asymptotic solutions of the velocity potentials and the second-order Stokes wave solutions of the associated elevations of the interfacial waves are presented based on the small amplitude wave theory, and the Kelvin-Helmholtz instability of interfacial waves is studied. As expected, for three-layer stratified fluid with background current, the first-order asymptotic solutions (linear wave solutions), dispersion relation and the second-order asymptotic solutions derived depend on not only the depths and densities of the three-layer fluid but also the background current of the fluids, and the second-order Stokes wave solutions of the associated elevations of the interfacial waves describe not only the second-order nonlinear wave-wave interactions between the interfacial waves but also the second-order nonlinear interactions between the interfacial waves and currents. It is also noted that the solutions obtained from the present work include the theoretical results derived by Chen et al (2005) as a special case. It also shows that with the given wave number k　(real number) the interfacial waves may show Kelvin-Helmholtz instability.
Energy of excitons and probability distribution of electrons in columned composite system composed of quantum dots and quantum wires
Authors: Zheng Rui-Lun  ,   重庆文理学院物理与信息工程系,重庆 402160
Published: December 2020

Equations of excitons in columned composite systems composed of quantum dots and quantum wires have been formulated. Then the energy of excitons is solved by the perturbation theory. From the example of CdS/HgS/CdS/HgS/CdS columned composite systems composed of quantum dots and quantum wires, the electric probability distribution in this system and the dependence of energy of excitons on the size of system are studied. The results show that：(1) The energies of electrons, holes and excitions in this system all decrease as the height, h0, of quantum dots increases and the impact of the interaction of electrons holes to the energies of the ground excitons is greater than that of the excitons. (2) The probability distribution of the electrons is undulating in the ridial direction, and the probability tends to zero on the axis and near the surface and is maximal near R/2. The probability distribution of electrons is vibratory near the quantum dots in the axial direction.
Optical properties of Pb1－xMnxSe thin films
Authors: Wang Qing-Lei  , Wu Hui-Zhen  , Si Jian-Xiao  , Xu Tian-Ning  , Xia Ming-Long  , Xie Zheng-Sheng  , Lao Yan-Feng  ,   (1)浙江大学物理系，杭州 310027; (2)中国科学院上海微系统与信息技术研究所信息功能材料国家重点实验室，上海 200050
Published: December 2020

High quality Pb1-xMnxSe(0≤x≤0.0681) thin films have been grown on BaF2(111) substrates by molecular beam epitaxy. Optical and structural properties of the Pb1-xMnxSe films have been studied using transmission spectrum and high resolution Ｘ-ray diffraction(HRXRD).HRXRD paterns indicate that Pb1-xMnxSe films have cubic-phase structure,and MnSe phase separation is not observed. The film orientation is parallel to (111) surface ofsubstrate. The lattice constant of Pb1-xMnxSe films decreases with increasing Mn content. The Mn content can be obtained by using Vegard's formula. Sharp absorption edges were observed in the transmission spectrum of Pb1-xMnxSe films.The fundamantal band gap of the Pb1-xMnxSe films was obtained by simulation, which increases almost exponentially from 0.28eV at x=0 to 0.49eV at x=0.0681. The refractive index in the wavelength ranged from 4 to 9.5 μm has also been obtained.
Synthesis and thermoelectric properties of p-type Ba8Ga16ZnxGe30－x clathrates
Authors: Deng Shu-Kang  , Tang Xin-Feng  , Zhang Qing-Jie  ,   武汉理工大学材料复合新技术国家重点实验室，武汉 430070
Published: December 2020

Ba8Ga16ZnxGe30-x(x=3, 4, 5, 6) clathrates with different Zn contente were synthesized by melt method reaction and spark plasma sintering. The effect of Zn composition on the thermoelectric properties were investigated. The results show that all samples behave p-type conductor. The electric conductivity and room-temperature carrier mobility decrease with increasing Zn content, and the room-temperature carrier density Np increases with increasing Zn content. Of all p-type Ba8Ga16ZnxGe30-x compounds, Ba8Ga16Zn3Ge27 has the highest Seebeck coefficient, the value of which is 234 μV·K-1 at 300 K, and reaches as high as 295 μV·K-1 around 700 K. The thermal conductivity of Ba8Ga16ZnxGe30-x decrease with increasing x. The maximum ZT value of 0.38 is obtained at 806 K for Ba8Ga16Zn3Ge27.
New solitary-wave-like solutions and exact solutions to variable coefficient generalized KdV equation
Authors: Mao Jie-Jian  , Yang Jian-Rong  ,   江西上饶师范学院物理系，上饶 334001
Published: December 2020

By the transforming with general KdV equation, the solutions of the variable coefficient generalized KdV equation are constructed firstly. As a result, we successfully obtain the new exact Jacobi elliptic function solutions, solitary-wave-like solutions, trigonometric function solutions and Weierstrass elliptic function solutions of variable coefficient generalized KdV equation.
Approximate synchronization of strongly coupled chaotic systems
Authors: Wu Ye  , Xiao Jing-Hua  , Zhan Meng  ,   (1)北京邮电大学理学院,北京  100876; (2)中国科学院武汉物理与数学研究所,武汉  430071; (3)中国科学院武汉物理与数学研究所,武汉  430071;中国科学院研究生院,北京  100049;北京邮电大学理学院,北京  100876
Published: December 2020

The chaotic synchronization in a one-way coupled oscillator array is studied. We find that, in certain coupling schemes (for example, the variable y driving x in the Lorenz system) and under proper coupling strengths, a nonlocal approximate synchronization happens between the first and the third oscillator, or all succeeding ones, which are not directly connected, accompanied with a desynchronization between the first and the closest, namely the second one. More detailed observation finds that under sufficiently strong coupling, there exists a single-driving-signal (not all three variables) synchronization between the first and the second oscillator that transfers the synchronization information to all remaining oscillators in the array. The nonlocal synchronization is a general phenomenon that has been observed in other systems.
Neutron 3PF2 superfluidity in neutron matter and the effect of microscopic three-body force
Authors: Cui Chang-Xi  , Zuo Wei  ,   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 100049
Published: December 2020

The neutron 3PF2 pairing gap in pure neutron matter has been studied by using the Brueckner-Hartree-Fock(BHF) approach and the BCS theory. We have concentrated our attention on investigating the three-body force effect on the neutron superfluidity in the 3PF2 channel. The calculated results indicate that the three-body force enhances remarkably the 3PF2 superfluidity in neutron matter. When adopting the BHF single-particle spectrum, the three-body force turns out to increase the maximum value of the pairing gap from about 0.22MeV to about 0.5MeV.
Infrared absorption of VO2 based Mott transition field effect transistor dependent on optical phonon in α-SiN: H films
Authors: Chen Chang-Hong  , Huang De-Xiu  , Zhu Peng  ,   华中科技大学武汉光电国家实验室,武汉 430074
Published: December 2020

VO2 based Mott transition field effect transistor is a new element to be incorporated between microbolometer sensitive pixels and on-chip read-out circuitry to fully realize the planar integrated infrared focal plane array. Based on their dielectric dispersions in Lorentz model, its infrared absorption was studied by the theory of reflection from Al surface plasma and absorption by optical phonons in VO2 and especially in α-SiN: H films. The present paper reports on the properties of the absorption in different wavelength regions and the dependence on the thickness of the nitride passivation layer, the absorbance spectra for the layer with thickness of λ/4n after the phase delay is corrected, and the changes in the spectra caused by the transition in the VO2 film.
Optical power limiting effect of stimulated Brillouin scattering in CS2 media under non-focusing pump
Authors: Gong Hua-Ping  , Lü Zhi-Wei  , Lin Dian-Yang  , Liu Song-Jiang  ,   哈尔滨工业大学光电子技术研究所，哈尔滨 150001
Published: December 2020

Adopting noise initiation model of stimulated Brillion scattering (SBS), the characteristic of transmitted energy and power in CS2 liquid media under non-focusing pump is investigated numerically. The results show that, the waveform of transmitted pulse with increasing input energy shows the characteristic of power limiting. And the transmitted energy varies linearly with input energy withont the energy limiting effect. When 1053 nm 20 ns Nd:YLF laser was used as pump in a 3∶1 inverse expansion system are using attenuators to adjust input energy in the rang of 2 to 92 mJ, the rules of transmitted energy and waveform versus input energy are acquired, and compared with the results of focusing pump. The experimental results are in good agreement with the theoretical simulations. Because the optical breakdown takes place at high input energy under focusing pump, the power limiting with non-focusing pump is applicable under the circumstances of high power and energy.
Steering of optical beams in strongly nonlocal nonlinear media by spatial phase modulation
Authors: Qin Xiao-Juan  , Shao Yi-Quan  , Guo Qi  ,   (1)华南师范大学光子信息技术广东省高校重点实验室，广州 510006; (2)华南师范大学光子信息技术广东省高校重点实验室，广州 510006;广东广播电视大学，广州 510091; (3)内江师范学院物理学与电子信息工程系，内江 641112
Published: December 2020

The basic idea is to impose sinusoidal phase modulation to an optical beam and then make it propagate in a strongly nonlocal nonlinear medium with normalized symmetrical real spatial response.The spatial phase modulation splits the input beam into multiple sub-beams, while the nonlocal nonlinear medium shapes the sub-beams into spatial solitons, whose directions and power can be controlled by changing the modulation parameters/We present numerical results to show how the deflection and the detachment of beams are achieved.
Modulation instability of fiber Bragg gratings with Gaussian apodization
Authors: Jia Wei-Guo  , Shi Pei-Ming  , Yang Xing-Yu  , Zhang Jun-Ping  , Fan Guo-Liang  ,   内蒙古大学物理系，呼和浩特 010021
Published: December 2020

The coherently coupled nonlinear Schrdinger (NLS) equation of the propagation of light pulse in fiber Bragg gratings has been utilized to study the modulation instability of laser pluses in fiber Bragg gratings with Gaussian apodization function, not only in the anomalous dispersion regime, but also in the normal dispersion regime. The results show that modulation instability can occur in both regimes. The regular gain spectra are observed obviously when input power reaches a definite value in the anomalous dispersion regime. The modulation instability can increase from a fixed value to infinity when the input power is in the region of modulation instability in normal dispersion regime. Furthermore, the gain spectra are restrained by Gaussian apodization function in both regimes.
First-principles study on the electronic structure and optical properties of ZnO doped with transition metal and N
Authors: Duan Man-Yi  , Xu Ming  , Zhou Hai-Ping  , Shen Yi-Bin  , Chen Qing-Yun  , Ding Ying-Chun  , Zhu Wen-Jun  ,   (1)四川师范大学物理与电子工程学院与固体物理研究所,成都 610068; (2)四川师范大学物理与电子工程学院与固体物理研究所,成都 610068;中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室，绵阳 621900; (3)四川师范大学物理与电子工程学院与固体物理研究所,成都 610068;重庆邮电学院光电工程学院,重庆 400065
Published: December 2020

The band structure, density of states, electron density difference and optical properties of ZnO co-doped with transition metal (Mn, Fe, Co, or Cu) and N have been investigated by using density functional theory based on first-principles ultrasoft pseudopotential method. The optical properties of co-doped ZnO are similar to those of ZnO doped only with transition metal (Mn, Fe, Co and Cu), but rather different from those of pure ZnO. Moreover, our calculation indicates that co-doping of transition metal (Mn, Fe, Co, and Cu) and N is in more favor of the formation of p-type ZnO.
Characteristic of alternating current hopping conductivity in one-dimensional binary disordered system with off-diagonal correlations
Authors: Ma Song-Shan  , Xu Hui  , Li Yan-Feng  , Zhang Peng-Hua  ,   中南大学物理科学与技术学院，长沙 410083
Published: December 2020

Based on a tight-binding disordered model describing a single electron band, we establish a model of one-dimensional binary disordered systems with off-diagonal correlations, and derive the alternating current (ac) conductance formula. By calculating the ac conductivity, the function of disorder and off-diagonal correlations in electronic transport are analyzed, and the dependence of the ac conductivity on the field frequency and the temperature is studied. The results indicate that the ac conductivity of one-dimensional binary disordered system decreases with the increasing of the degree of lattices energy disorder. And the ac conductivity of the system is also dependent on the probabilities p, which represents the degree of compositional disorder of the system to some extent. The ac conductivity of system first decreases with the increasing of p, then increases with farther increasing of p. We also find that off-diagonal correlations lead to delocalization and enhance the ac conductivity of the system，namely, the ac conductivity of one-dimensional binary disordered system with off-diagonal correlations is larger than that of uncorrelated system in the Anderson limit. Moreover, the ac conductivity of one-dimensional binary disordered system decreases with the increasing of temperature, and increases drastically with the increasing of the frequency of the electric field.
Controlling the interfacial structure of cubic boron nitride thin film prepared by plasma-enhanced chemical vapor deposition
Authors: Yang Hang-Sheng  , Xie Ying-Jun  ,   (1)浙江大学材料与化学工程学院，杭州 310027; (2)浙江大学流体传动及控制国家重点实验室，杭州 310027
Published: December 2020

The existence of an initial amorphous layer and a turbostratic boron nitride transition layer is one of the main hindrance to heteroepitaxial growth of cubic boron nitride on silicon susbtrate. In this paper, we systematically studied the effect of substrate pretreatment on the amorphous layer composition of cBN films prepared by plasma enhanced CVD, and found that the possible causes for the amorphous layer formation are the native silicon oxide, the oxygen remaining in the vacuum chamber, high energy ion bombardment, and the formation of silicon nitride at high substrate temperature. By 1200 K heating of silicon susbtrate in H2 atmosphere and by controlling the deposition temperature at below 900 K, the crystallinity of silicon susbtrate surface could be retained and the amorphous initial layer removed. Moreover, when the substrate bias is near the puttering effect dominated region, only pure turbostratic boron nitride film could be deposited. By reducing the time span of the substrate bias in puttering effect dominated region during the time dependent biasing technique, the turbostratic boron nitrde transition layer could be partitally eliminated. Nucleation of cubic boron nitride directly on silicon substrate was confirmed by high-resolution transmission electron microscopy. Our results may open up a possible route to cubic boron nitrde eptaxial growth on silicon substrate and lead to the potential high-temperature electronic applications of cubic boron nitride thin films.
Ferromagnetic resonance in ferromagnetic bilayer films under the stress anisotropy
Authors: Rong Jian-Hong  , Yun Guo-Hong  ,   (1)内蒙古大学理工学院物理系，呼和浩特 010021; (2)内蒙古大学理工学院物理系，呼和浩特 010021;内蒙古师范大学物理与电子信息学院，呼和浩特 010022
Published: December 2020

The ferromagnetic resonance (FMR) technique has been used to investigate the properties of ferromagnetic/nonmagnetic/ferromagnetic systems. We derived the FMR dispersion relation, taking into account the competition between the indirect interlayer coupling and stress anisotropy. In this case，one of the layers A has a strong in-plane anisotropy compared with the coupling strength and the in-plane anisotropy of the other layer B. As the applied field increases，magnetization of layer B may suddenly switch from the antiparallel configuration to the saturated state. The discontinuities are more important for the optical than for the acoustic modes. For the optical mode，the effect of interlayer coupling and stress anisotropy on the HR vs φH curves is more apparent.
Space charges formed in the hot compression molding process of low density polyethylene
Authors: An Zhen-Lian  , Yang Qiang  , Zheng Fei-Hu  , Zhang Ye-Wen  ,   同济大学波耳固体物理研究所，上海 200092
Published: December 2020

The properties of space charges formed in the hot compression molding process of low density polyethylene (LDPE) have been studied by measuring the open-circuit thermally stimulated discharge (TSD) current， in situ TSD charge and the isothermal charge decay. The results showed that the space charges with high stability at room temperature (RT) are trapped in two kinds of traps: shallow traps and deep traps with central depths of about 0.92eV and 1.31eV, respectively. Preliminary analysis indicates that the shallow traps and deep traps should be located in the surface layer and in the bulk of the sample, forming surface traps and bulk traps，respectively.
Reseach on improving the electron injection in SSCL
Authors: Li Yuan  , Zhao Su-Ling  , Xu Zheng  , Zhang Fu-Jun  , Huang Jin-Zhao  , Song Lin  , Ouyang Ping  ,   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
Published: December 2020

The key to improve the efficiency of SSCL (solid state cathodoluminescence) is to improve the injection and acceleration of electrons in the accelerating layer. The electron acceleration ability of SiO is better than that of ZnS，while the latter is better than the former in the ability of injecting charges. So our attention was turned to the complex accelerating layer SiO2/ZnS，and prepared two kinds of devices to see whether the short peak occurrs. One of them is the low voltage mono-side recombination device, the othe the high voltage impacted two-side device. In result，under low voltage，the performance of the complex accelerating layer is superior to that of SiO2 and inferior to that of ZnS. Under high voltage，the complex accelerating layer is the best of all devices. Meanwhile，SiO2 was still found to be the main accelerating layer，yet ZnS is very useful for improving the performance in electron injection of SSCL device.
The electronic structure of the microstructure of Mg-Zr alloys
Authors: Liu Gui-Li  ,   沈阳工业大学建筑工程学院，沈阳  110023
Published: December 2020

The electronic structure parameters (such as the structure energy, atomic binding energy of α-Mg and α-Zr phase; the interface energy of Mg/Zr; the surface energy of Mg; the interacting energy between Zr atoms or impurity atoms; the density of state and the charge variety of Mg and Zr in auoys) were calculated by recursion method. The calculated results show that: the shape of the density of states of Zr is different from Mg in the cryctal grain, but is similar to the Mg at the Mg/Zr interface, which means the electronic structure environment of the interface of Mg/Zr is similar for Zr and Mg, which provides the condition for Mg to nucleate on the surface of Zr. The structure energy and the atomic binding energy of α-Zr phase are lower than that of α-Mg, and the interface energy of Mg/Zr is lower than the surface energy of Mg. This explains from energy point of view the experiment phenomenon that Zr precipitates from Mg liquid before α-Mg solidifies, and it acts as good centers for heterogeneous nucleation to refine α-Mg grains. The interacting energy between atoms indicated that Zr atoms attracts each other, so they can form Zr atom clusters in Mg easily, and may combine with impurity atoms to form compounds, which will weaken the effect of the refinement of Mg grains. But it cleans the Mg alloys and improves the performances of Mg alloys. The charge transfer between Mg and Zr produces the ionic bond, which reduces the coefficient of diffusion of Mg. This makes the growing of α-Mg grain difficult, and leads to the refinement of α-Mg grain.
Analysis of valence electron structures and calculation of magnetic properties of Nd2Fe14B
Authors: Wu Wen-Xia  , Guo Yong-Quan  , Li An-Hua  , Li Wei  ,   钢铁研究总院功能材料研究所，北京  100081
Published: December 2020

The valence electron structure and magnetic properties of Nd2Fe14B intermetallics have been investigated using empirical electronic theory of solids and molecules. The calculations fit the experimental data well. It reveals that the magnetic properties of Nd2Fe14B are proportion to the 3d electrons of Fe atoms. The moments increase from the Fe at 4c site to the Fe at 16k2 site, which is due to the changes between the valence electrons, dumb pair electrons and 3d magnetic electrons. According to the calculation, 78% of dumb pair electrons and 18% of valence electrons in d orbit change to magnetic electrons, this causes the increase of moments from the Fe at 4c site to the Fe at 16k2 site. Both Curie temperature and moments are proportion to the coordination numbers of the Fe atom, however, the Curie temperature decrease with the weighted equal bond numbers Iσ. The effect on Curie temperature of non-magnetic elements Nd and B is derived from the change of the Fe—B and Fe—Nd bond distances.
Study on a class of chaotic systems with fractional order
Authors: Zhao Pin-Dong  , Zhang Xiao-Dan  ,   北京科技大学应用科学学院,北京  100083
Published: December 2020

In this paper, a class of chaotic systems with fractional order is generalized and their topological equivalence is proved. It indicates that the necessary condition for a system with fractional order to generate chaotic attractor is to maintain the stability of the equilibrium points of the system. Numerical simulation shows that, similar to chaotic systems with integer order, the class of chaotic systems with fractional order can also generate a couple of double-scroll chaotic attractors.
Experimental study for neutron-rich exotic nuclei 17B
Authors: Hu Zheng-Guo  , Wang Meng  , Xu Hu-Shan  , Sun Zhi-Yu  , Wang Jian-Song  , Xiao Guo-Qing  , Zhan Wen-Long  , Xiao Zhi-Gang  , Mao Rui-Shi  , Zhang Hong-Bin  , Zhao Tie-Cheng  , Xu Zhi-Guo  , Wang Yue  , Chen Ruo-Fu  , Huang Tian-Heng  , Gao Hui  , Jia Fei  , Fu Fen  , Gao Qi  , Han Jian-Long  ,   (1)中国科学院近代物理研究所，兰州  730000; (2)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  100049
Published: December 2020

The total reaction cross section of 17B on C target has been measured by using the transmission method at the Radioactive Ion Beam Line in Lanzhou (RIBLL). Assuming 17B consisting of a core 15B plus two halo neutrons, the total cross section of 17B on C target was calculated with the zero-range Glauber model where Gaussian plus HO density distributions were used. It fitted the experimental data very well. A large diffusion was found about the density distribution of 17B. Based on the analysis, the two neutrons halo of 17B was confirmed.
The rotational excitation partial cross sections for the He-HI collisions
Authors: Yu Chun-Ri  , Wang Rong-Kai  , Yang Xiang-Dong  , Yin Xun-Chang  ,   (1)安庆师范学院物理与电气工程学院,安庆  246133; (2)贵州师范大学理学院,贵阳  550001; (3)四川大学原子与分子物理研究所,成都  610065
Published: December 2020

The close coupling approach is used to calculate the elastic and inelastic partial cross sections for collisions of helium atoms with hydrogen iodide molecules based on the intermolecular potential introduced in our previous research. The calculations are performed separately at the incident energies of 40, 75 and 100 meV. This study indicates that the excitation partial cross sections converge faster than the elastic partial cross section for each of the incident energies considered here. The excitation partial cross sections converge more rapidly for the higher excited states, and more slowly for the higher incident energies.
Theoretical study on the first hyperpolarizabilities of stilbene derivatives
Authors: Wang Lei  , Hu Hui-Fang  , Wei Jian-Wei  , Zeng Hui  , Yu Ying-Ying  , Wang Zhi-Yong  , Zhang Li-Juan  ,   湖南大学物理与微电子科学学院，长沙  410082
Published: December 2020

Static first hyperpolarizabilities of a series of stilbene derivatives are calculated at the CPHF/6-311G(d) level. the molecules which possess the electron push-pull pair and delocalized conjugated bridge structure have larger first hyperpolarizabilities because of the intramolecular charge transfer. The influence of position of the substitution, strength and number of donors and acceptors, and their coplanarity and asymmetry is discussed. The results indicate that the molecules may have larger first hyperpolarizabilities when the molecules have stronger and more donors and acceptors, large asymmetry of HOMO and LUMO, better coplanarity and higher accentricity. This work attemps at finding out the relationship between the structure and the property, thus providing theoretical basis for designing nonlinear optical molecules.
The improvement of fiber parametric amplifier pulse source via modulation of signal light
Authors: Jiang Yang  , Yu Jin-Long  , Hu Hao  , Zhang Ai-Xu  , Zhang Li-Tai  , Wang Wen-Rui  , Yang En-Ze  ,   (1)天津大学电子信息工程学院光纤通信实验室，光电信息技术科学教育部重点实验室，天津  300072; (2)天津大学电子信息工程学院光纤通信实验室，光电信息技术科学教育部重点实验室，天津  300072；贵州大学理学院,贵州省光电子技术与应用重点实验室,贵阳  550025
Published: December 2020

Starting from the four-wave maxing coupled equations, we obtain the optical field expression of a fiber optical parametric amplifier (FOPA) pulse source. Furthermore, we analyze the evolvement of pulse frequency chirp and amplitude when the signal light is phase or intensity modulated. It is concluded that the pulse width has no significant improvement but the extinction ratio is improved when the signal light is intensity modulated; however, when the signal light is phase modulated, the pulse has enhanced positive linear frequency chirp, which means that we may obtain shorter pulse than that of the FOPA based pulse source which has the same pump power but without phase modulation on signal light. Finally, theexperimental results of 10 GHz operation demonstrated the validity of our theoretical analysis. Using the FOPA pulse source with 05 W average pump power and phase modulated signal light, the transform limited pulse is obtained which has 22 dB extinction ratio and 52 ps pulse width, which is 2 ps narrower than that without modulation.
Study on quantum cryptography using orbital angular momentum states of photons
Authors: Su Zhi-Kun  , Wang Fa-Qiang  , Lu Yi-Qun  , Jin Rui-Bo  , Liang Rui-Sheng  , Liu Song-Hao  ,   华南师范大学信息光电子科技学院，光子信息技术广东省高校重点实验室，广州  510006
Published: December 2020

We present a simple quantum cryptographic scheme that encodes information in two orthogonal orbital angular momentum states. The states used in this scheme are invariant under rotations of the propagation direction，making this implementation independent of the alignment between the reference frames of Alice and Bob. Besides，since the two orbital angular momentum states are orthogonal，100% use of the photons is attained，which increases the key generation rate of the protocol.
Experimental investigation of superhydrophobic properties of the surface constructed by nanoparticles
Authors: Gu Chun-Yuan  , Di Qin-Feng  , Shi Li-Yi  , Wu Fei  , Wang Wen-Chang  , Yu Zu-Bin  ,   上海大学，上海市应用数学和力学研究所，上海市力学在能源工程中应用重点实验室，上海  200072
Published: December 2020

Two kinds of micro- and nano-structural surfaces were constructed with hydrophobic nanoparticles(HNPs)directly. One of the surfaces was formed by compressing the nano powder to a smooth slice, the other was made by adsorbing the nanoparticles on the surface of rock wafer. The contact angles between water drops and the surfaces were measured and the rolling process of a water drop on the nanoparticles-adsorbed rock surface was pictured. The scanning electron microscope(SEM) was used to observe the microstructure of these surfaces also. The results show that the inorganic nanoparticles modified by weak hydrophobic material could have strong hydrophobic property, even though it was strongly hydrophibic initially. The measured contact angles of water drop on the nanoparticle-adsorbed rock surface are always greater than 120°and the rolling angles are less than 7°. These data means that these surfaces are superhydrophobic apparently. The SEM pictures show that these surfaces are air-solid compound interfaces with irregular micro- and nano-structure. It is these special structures that lead to the formation of superhydrophobic surfaces, which are in agreement with the Cassie-Baxter model.
Anharmonic phonon coupling and phonon confinement in nanocrystalline anatase TiO2
Authors: Zhao Jian-Hua  , Chen Bo  , Wang De-Liang  ,   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

A temperature-dependent Raman scattering study of the Eg(1) mode was carried out at 83 to 723K for nanocrystalline anatase TiO2 with different sizes of 194，86 and 56nm. By means of a combined model of anharmonic coupling and phonon confinement，the Eg(1) Raman spectra were fitted and calculated. The results show that，the temperature-dependent lattice vibration fundamentals are essentially the same for the three samples. The blue shift of Raman frequencies mainly comes from the contribution of three-phonon processes. In order to get good fittings，both the three- and four-phonon processes need to be considered. With increasing temperature，the four-phonon process becomes more important and counteracts the effect of the three-phonon process. The anharmonic-decay-related phonon lifetime increases as nanocrystalline size decreases，and the smaller nanoparticles have slower anharmonic decay. At low temperatures，the phonon confinement is responsible for a much shorter phonon lifetime for the 56-nm nanocrystals. The phonon confinement induces a blue shift of the Eg(1) mode and an asymmetrical broadening at high frequencies. It has a relatively larger effect on the linewidth broadening than on the peak shift.
Change in stress of GaN light-emitting diode films during the process of transferring the film from the Si(111) growth substrate to new substrate
Authors: Xiong Chuan-Bing  , Jiang Feng-Yi  , Fang Wen-Qing  , Wang Li  , Mo Chun-Lan  ,   南昌大学教育部发光材料与器件工程研究中心,南昌  330047；晶能光电(江西)有限公司,南昌  330096
Published: December 2020

InGaN multiple-quantum-well(MQW) light-emitting diode(LED) thin films were successfully transferred from the original Si(111) substrate to new Si substrate, and then the vertical structure LEDs were fabricated. After the original substrate removal, the residual tensile stress in GaN layer of the transfferred film is partially relaxed, while the compressive stress in InGaN well layer is increased. When the buffer layer of the transferred LED film was eliminated, the tensile stress in GaN layer was shown to increase. However, the compressive stress in InGaN well layer was kept unvaried. The performance of the vertical LEDs was significantly improved compared with the lateral LEDs.
Resonant transmission of the terahertz pulse through a subwavelength metallic slit
Authors: Meng Kuo  , Wang Yan-Hua  , Chen Long-Wang  , Zhang Yan  ,   (1)北京市太赫兹波谱与成像重点实验室，省部共建太赫兹光电子学教育部重点实验室，首都师范大学物理系,北京  100037; (2)哈尔滨工业大学物理系，哈尔滨  150001
Published: December 2020

The transmission property of a single thin metallic slit with different widths has been investigated by terahertz (THz) time-domain spectroscopy. The experiment results show that in the effective spectroscopic range (02—26THz), the Fabry-Perot-like behavior was observed when the slit width decreases to a certain value. According to the theory of surface plasmon subwavelength optics, this resonant phenomenon was analyzed.
Analysis of the dynamics of upconversion in erbium-doped transparent lead lanthanum zirconate titanate ceramic
Authors: Li Xiao-Yan  , Zheng Zhi-Qiang  , Feng Zhuo-Hong  , Liu Jing  , Jiang Cui-Hua  , Kong Ling-Kai  , Ming Hai  ,   (1)福建师范大学物理与光电信息科技学院,福州  350007; (2)中国科学技术大学物理系,合肥  230026
Published: December 2020

The absorption and upconversion fluorescence spectra of Er3+ ions in Er3+ doped transparent lead lanthanum zirconate titanate(PLZT)ceramic were measured at room temperature. The radiative transition probabilities of the Er3+ ions were calculated using the absorption spectrum of Er3+ doped PLZT. Strong upconversion emission was observed in the upconversion luminescence of Er3+ doped PLZT. The green emission intensities at 540nm and 564nm were stronger than the red emission intensity at 678nm. The upconversion rate equations describing the dynamic process of the system have been deduced. The upconversion coefficients were estimated by numerically solving the rate equations and fitting the simulated curves to the measured data. The coefficients C22and C33 obtained are 091×10-18cm3/s and 1823×10-18cm3/s, respectively. The results show that evident upconvesion phenomenon can be observed in Er3+: PLZT transparent ceramics, which is consistent with our observation.
Study of complete bandgap of two-dimensional columnar photonic crystals
Authors: Cheng Xu-Pan  , Cao Quan-Xi  ,   西安电子科技大学技术物理学院，西安  710071
Published: December 2020

Plane wave expansion method was employed to study the relation between the bandgap of two-dimensional columnar photonic crystals and the filling ratio and dielectric constant ratio. It is shown that the complete bandgap does not increase monatonically with the dielectric constant ratio, but has a peak value instead.
Air bubble entrainment by breaking waves and estimation of the related statistical quantities
Authors: Zhang Shu-Wen  ,   广东海洋大学南海海洋环境研究所，湛江  524088
Published: December 2020

Based on the experiments, the energy loss from wave breaking εed, the bubble plume penetration depth zb, the rate of air entrainment　Q(z), and the turbulent kinetic energy dissipation rate εT(z) are estimated in this study. As a consequence, a simple bubble size spectrum model N(a,z) is proposed and the rate of energy dissipation due to air bubble entrainment and bubble fragment Hinze scale and bubble size spectrum are investigated under different sea states. It is indicated that the rate of energy dissipation due to air bubble entrainment ranges from 01 to 06 in low and moderate sea states, but may be negligible in the high sea state. Bubble fragment Hinze scale downshifts to the lower-frequency band as wind speed increases. Bubble size spectrum not only depends on the rate of air entrainment, the breaking rate, and the turbulent kinetic energy dissipation rate, but also strongly on the wind and sea state.
Constructing exact solutions to differential-difference equations via the coupled Riccati equations
Authors: Yang Xian-Lin  , Tang Jia-Shi  ,   湖南大学力学与航空航天学院，长沙  410082
Published: December 2020

An algebraic method to construct the exact solutions of nonlinear differential-difference equations is presented by introducing the coupled Riccati equations. As an example, we apply this method to the general lattice equation, the relativistic Toda lattice equations and the (2+1) dimensional Toda lattice equation. Some kink solitary wave solutions and complexiton solutions are obtained with the help of symbolic system Mathematica. Our method can also be applied to other nonlinear differential-difference equations.
Chaos control in the Josephson junction with a resonant harmonic excitation
Authors: Lei You-Ming  , Xu Wei  ,   西北工业大学应用数学系，西安  710072
Published: December 2020

In the present paper, the control of chaos in the Josephson junction with two different kinds of resonant harmonic excitations, namely the additive and parametric excitations, are investigated in detail. With the Melnikov method, we have obtained the regions of excitation amplitude in which heteroclinic chaos may be generated or suppressed. Meanwhile, for suppressing the heteroclinic chaos, we have determined the prereguisite relationships between parameters of the system excitation and the control excitation. The analytical results show that phase difference between the two excitations has important effect. Moreover, numerical methods show that the phase control method is feasible not only for controlling heteroclinic chaos, but also for controlling other types of chaos in nonautonomous systems. Comparing the effect of an additive harmonious excitation with that of a parametric one, we find the former one is more effective at the small resonant frequencies, while the latter one is more effective at the large ones.
Analysis of the geometric characteristic quantity of the periodic solutions of the chaotic oscillator system and the quantitative detection of weak periodic signal
Authors: Li Yue  , Xu Kai  , Yang Bao-Jun  , Yuan Ye  , Wu Ning  ,   (1)吉林大学地球物理系，长春  130026; (2)吉林大学信息工程系，长春  130012
Published: December 2020

We proposed a quantitative detection method for weak periodic signal in this paper. A result is obtained when analyzing the stable output of chaotic oscillator system in the large-scale periodic state, which shows that the average area of the periodic solution of the chaotic oscillator system is a steady geometric characteristic quantity of periodic solutions of the chaotic oscillator system. There is a steadily and monotonically increasing relation between the average area and the amplitude to be detected. When some parameters are defined, the precision of the geometric characteristic quantity can reach 10-6V2. The further quantitative detection of weak signals is built based on the two characteristics of the chaos system, namely the immunity to noise and sensitivity to weak signal. The simulation experiments shown that the immunity to noise will be enhanced along with the increase of amplitude detected while the precision can be guaranteed.
Fourth-order Colpitts chaotic oscillator
Authors: Yu Si-Min  ,   广东工业大学自动化学院，广州  510006
Published: December 2020

A novel fourth-order Colpitts chaotic oscillator is presented. Theoretic design and circuit implementation shows that the fourth-order Colpitts chaotic oscillator can be obtained by parallelizing a capacitor C3 with inductor L in a canonical third-order Colpitts chaotic oscillator. The resonance frequency is changed by adjusting the value of C3, and the oscillator becomes chaotic through doubling period bifurcation. The dynamical behaviors of the fourth-order Colpitts chaotic oscillator are further investigated, including equilibrium points, bifurcations and Lyapunov exponents. Finally, this approach is verified in both numerical simulations and circuit experiments.
Modulational instability of two-component dipolar Bose-Einstein condensates in an optical lattice
Authors: Huang Jin-Song  , Chen Hai-Feng  , Xie Zheng-Wei  ,   (1)川北医学院物理教研室，南充  637000; (2)四川师范大学物理与电子工程学院，低维结构物理实验室，成都  610066
Published: December 2020

From the linear stability analysis，the modulational instability (MI) of two-component dipolar Bose-Einstein condensates (BECs) in an optical lattice is studied. The relation of the region of MI with the on-site interaction and the site-to-site interaction induced by the dipole-dipole interaction is obtained. The results show that there is a great influence of site-to-site interaction on the MI of the two-component dipolar BECs in the optical lattices. This gives us some useful information for manipulating two-component dipolar BECs in practice.
The interaction potential of Ne-HF system and close coupling calculations of the scattering cross sections
Authors: Yu Chun-Ri  , Song Xiao-Shu  , Cheng Xin-Lu  , Yang Xiang-Dong  , Shen Chuan-Sheng  ,   (1)安庆师范学院物理与电气工程学院，安庆  246133; (2)贵州师范大学理学院，贵阳  550001; (3)四川大学原子与分子物理研究所，成都  610065
Published: December 2020

An analytic expression of the intermolecular interaction potential of the ground state of the Ne-HF system is obtained by nonlinear least square method to fit the intermolecular interaction energies，which have been calculated for the coupled cluster singles and doubles including connected triple excitations level andwith the augmented correlation consistent polarized quadruple zeta basis set CCSD (T)/aug-cc-pVQZ. Differential and partial cross sections for the Ne-HF scattering are obtained by means of converging close coupling calculations from the fitted ab initio CCSD (T) potential. The calculation is performed separately at the incident energies 60，75，100 and 150meV. The tendency of the scattering cross sections varying with incident energy and the influence of the state-to-state excitation cross sections on the total inelastic scattering cross section are discussed in detail.
Hybrid method for investigation of electromagnetic scattering interaction between the conducting target and rough sea surface
Authors: Wang Rui  , Guo Li-Xin  , Qin San-Tuan  , Wu Zhen-Sen  ,   西安电子科技大学理学院，西安  710071
Published: December 2020

A current based hybrid method combining the MOM with the Kirchhoff approximation for analysis of scattering interaction between a two-dimensional infinitely long conducting target with arbitrary cross section and a 1-D rough sea surface with PM spectrum is proposed. The electromagnetic scattering region in the hybrid method is split into KA region and MOM region，respectively. The computational time of the hybrid method mainly depends on the number of unknowns of the target due to the induced current on the rough sea surface does not need to be calculated. The composite bistatic scattering cross section for the infinitely long cylinder above the rough sea surface with PM spectrum is calculated，the numerical results are compared and verified with those obtained by the conventional MOM，which shows the high efficiency of the hybrid method. Finally，the influence of the windspeed，the size and location of the target on the bistatic scattering cross section with different polarizations is discussed in detail.
The kernel function’s simplification and its characteristic analysis in integral theory of diffraction gratings
Authors: Zhang Shan-Wen  , Bayanheshig  ,   (1)中国科学院长春光学精密机械与物理研究所，长春  130033; (2)中国科学院长春光学精密机械与物理研究所，长春  130033；中国科学院研究生院，北京  100049
Published: December 2020

On the base of perfect conductivity integral theory of diffraction gratings，after transforming the grating equation，the image equation of diffraction wave vector in Littrow mounting is given. Using the equation and in view of the power function property，the infinite series，which represents the kernel function，is transformed into the sum of a symmetrical series and a geometrical series. Compared with the primary integral method，from the view of numerical calculation，the new kernel function can reduce the computing time and improve the convergence. The extension results show that the power function character can improve convergence in the deviated Littrow mounting.
Analysis and evaluation of Glan-Taylor prism’s image quality in a new polarization interference imaging spectrometer
Authors: Wu Hai-Ying  , Zhang Chun-Min  , Zhao Bao-Chang  ,   (1)西安交通大学理学院，西安  710049; (2)中国科学院西安光学精密机械研究所空间光学实验室，西安  710068
Published: December 2020

Glan-Taylor prism is one of the most important polarization components of the new polarization interference imaging spectrometer developed in our laboratory. The principle of beam splitting and imaging of Glan-Taylor prism are presented. This paper deduces the propagation track of light in Glan-Taylor prism by ray-tracing method at random incidence angle and the theoretical expressions of image displacement and chromatic aberration are derived. The results will provide a theoretical basis for the study of new polarization interference imaging spectrum technology and the development of apparatuses.
The influence of spectral lines and coupling coefficient on mutual injection locking of fiber lasers
Authors: Chen Zi-Lun  , Zhou Pu  , Xu Xiao-Jun  , Hou Jing  , Jiang Zong-Fu  ,   国防科学技术大学光电科学与工程学院，长沙  410073
Published: December 2020

Mutual injection locking is recognized as one of the most important and promising research directions for the fibre laser combining technology. Basing on the mutual injection locking of the two fiber lasers, the far field and the spectra of the two fiber lasers were inspected by infrared CCD and optical spectrum analyzer when the spectrum of one fiber laser and the coupling coefficient were changed. From the experiment, we conclude that the stronger was the mutual injection locking when the closer the spectra of the two fiber laser are; and the mutual injection locking would fail when the difference in the frequencies exceeds the locking range, which can be extended by increasing the coupling coefficient of the fiber lasers.
A novel phase self-compensation isolator based on TE-TM mode conversion
Authors: Zeng Wei-You  , Xie Kang  , Jiang Hai-Ming  , Chen Kai  ,   (1)电子科技大学光电信息学院，成都  610054; (2)电子科技大学光电信息学院，成都  610054；湖北汽车工业学院理学部，十堰  442002
Published: December 2020

The intrinsic factors of magneto-optical waveguide isolator based on 45° nonreciprocal mode conversion and 45° reciprocal mode conversion are introduced. A novel phase self-compensation isolator is designed and simulated by the full-vectorial FD-BPM. The insertion loss of this isolator is -12dB and the isolation is-34dB.
Transmission properties of the generalized Fibonacci quasi-periodical phononic crystal
Authors: Cao Yong-Jun  , Yang Xu  ,   内蒙古师范大学物理与电子信息学院，呼和浩特  010022
Published: December 2020

In this paper, the model of a one-dimensional generalized Fibonacci quasi-periodical phononic crystal is firstly proposed, the transmission coefficients of the elastic waves through this 1D quasi-periodical phoninic crystal are numerically calculated, and the obtained transmission coefficients are compared with those of the phononic crystals with periodical structure and with normal Fibonacci structure. The results show that the band gap can also be found in the phononic crystals with the generalized Fibonacci quasi-periodical structure, and the frequency range of the gap is larger than that of both the periodical structure and the normal Fibonacci structure. However, there are more strongly localized resonant modes in the gap of the generalized Fibonacci quasi-periodical phononic crystals. This study to the localized modes is useful to the fabrication of the acoustic or elastic wave filters.
Simulation study of effects of cooling rate on evolution of micro-cluster structures during solidification of liquid Pb
Authors: Zhou Li-Li  , Liu Rang-Su  , Hou Zhao-Yang  , Tian Ze-An  , Lin Yan  , Liu Quan-Hui  ,   湖南大学物理与微电子科学学院，长沙  410082
Published: December 2020

A tracing simulation has been performed for the solidification of liquid Pb at six different cooling rates by molecular dynamics method. The pair distribution function g(r) curves, the bond-type index method of Honeycutt-Andersen(HA), the cluster-type index method and average coordination numbers have been used to analyze the evolution of micro-cluster structures during solidification processes. The results show that there is a critical cooling rate (in the range of 1×1013 and 5×1012 K·s-1) for forming amorphous or crystal structure. When the cooling rate is higher than the critical cooling rate, amorphous structures are formed mainly with the 1551,1541 and 1431 bond-types. When the cooling rate is lower than the critical cooling rate, the crystal structures mainly with the 1441 and 1661 bond-types or the bcc basic cluster (14 6 0 8 0 0) are firstly formed, and keep stable for a period of time, and then rapidly transform to the partial crystalline structure mainly with the 1421 and 1422 bond-types, or the fcc basic cluster (12 0 0 0 12 0) and the hcp basics cluster (12 0 0 0 6 6) coexisting in a certain proportion . At the same time, it has been found that there are obvious effects of the cooling rate on the relative proportion of the fcc basic clusters to the hcp basic clusters, the smaller the cooling rate is, the bigger relative proportion of the fcc basic cluster, and the system tends to form highly perfect fcc crystal structure.