bluuebunny/crossref_metadata_2025 huggingface dataset:
Force distribution in static granular matter in two dimensions
Authors: Sun Qi-Cheng  , Wang Guang-Qian  ,   清华大学水沙科学与水利水电工程国家重点实验室，北京  100084
Published: December 2020

Granular matter is a large assemblage of individual solids, which is fundamentally different from any other type of matters, such as solid and liquid. The intrinsic nature of granular matter is of multi-scale, inclusive of microscale of particle size, mesoscale of force chain and macroscale of the bulk of granular matter. The mesoscale of force chain bridges single particle and granular matter, and leads to unique properties and behaviours of granular matters, and thus acts as the key issue in the study of granular matter. In this work, we firstly propose a multiscale methodology for granular matter dynamics, and point out that the characteristics of force chain is the key to the granular dynamics. We then propose a discrete element model based on rigorous Hertzian contact law and Mindlin-Deresiewicz contact theory for normal and tangential contact forces, respectively. The static packing of 12000 sand grains under the action of gravity in two dimensions is simultaed, and the force chain pattern and stress distribution are obtained. The force distribution, force chain length distribution and the angle distribution are calculated and analyzed. Friction coefficient of particle is found to be a very sensitive factor affecting properties of granular matter, and thus its influence on the above parameters is studied as well.
Stability and approximate solution of a relative-rotation nonlinear dynamical system under harmonic excitation
Authors: Shi Pei-Ming  , Liu Bin  , Liu Shuang  ,   燕山大学信息科学与工程学院，秦皇岛  066004
Published: December 2020

The dynamical equation of a relative-rotation nonlinear dynamical system with nonlinear elastic force and common friction and harmonic excitation is deduced. The singularity stability of the autonomous system is studied by constructing the Lyapunov function. The approximate solution of unautonomous equation with different resonance response under harmonic excitation is obtained by the method of multiple scales, and the stability of main resonance stable state of motion is studied.
Quantum secret sharing with bidirectional authentication
Authors: Sun Ying  , Du Jian-Zhong  , Qin Su-Juan  , Wen Qiao-Yan  , Zhu Fu-Chen  ,   (1)北京邮电大学理学院，北京  100876; (2)北京邮电大学网络与交换技术国家重点实验室，北京  100876；北京邮电大学理学院，北京  100876; (3)现代通信国家重点实验室，成都  610041
Published: December 2020

A quantum secret sharing scheme with two-way authentication was proposed and discussed. Based on two-particle quantum entanglement, the scheme is implemented using the Hash function and the quantum local operations. The authentication keys and the secret order of transmitted particles ensure the security of the scheme. One Bell state can be used to share two classical bits on average if the particles for authentication and eavesdropping detection are not concernred.
Anti-synchronizing different chaotic systems using active sliding mode control
Authors: Liu Fu-Cai  , Song Jia-Qiu  ,   燕山大学自动化系,秦皇岛  066004
Published: December 2020

An active sliding mode control is designed to anti-synchronize different chaotic systems. The closed loop error dynamics depends on the linear part of the response systems and parameters of the controller. Therefore, the anti-synchronization rate can be adjusted through these parameters. Analysis of the stability for the proposed method is done based on the Lyapunov stability theorem. Finally, numerical results are presented for the Lorenz, Chen and Lü systems. This method may realize the anti-synchronization quickly, and the robust stability is good.
Synchronization and control of autocatalytic chemical reaction in continuous stirring tank reactor
Authors: Li Yong  , Zhang Xiao-Fang  , Bi Qin-Sheng  ,   江苏大学理学院，镇江  212013
Published: December 2020

The synchronization problem for a chemical reaction system composed of two continuous stirring tank reactorv is explored. Based on Lyapunov stability theory, a new method is proposed to design the controlling function. The range of the coupling strength to realize the synchronization between the two chemical systems is investigated both for the case with static velocity and with periodically disturbed velocity of the input material. Numerical simulations are then performed to demonstrate the effectiveness of the proposed scheme, which show that the method is suitable for both the autonomous system and the non-autonomous system with periodic perturbation.
A cellular automaton model for studying the on-ramp control of highway
Authors: Mei Chao-Qun  , Huang Hai-Jun  , Tang Tie-Qiao  ,   (1)北京航空航天大学交通科学与工程学院，北京  100083; (2)北京航空航天大学经济管理学院，北京  100083; (3)北京航空航天大学经济管理学院，北京  100083；首都经济贸易大学统计学院，北京  100070
Published: December 2020

In this paper, a cellular automaton model for studying the on-ramp traffic control problem of highway is proposed. The number of vehicles contained in a highway segment adjacent to the ramp merging region is used to control the on-ramp signal light. Simulation results show that the on-ramp control can improve the highway traffic, particularly when the ramp traffic is heavy. It is found that the location of detected highway segment, the length of ramp merging region and the control parameter governing the light change affect the highway and ramp traffic simultaneously. These three parameters should be coordinately designed for the improvement of both highway and ramp traffic. In general, the detected highway segment should be located at the upstream of the ramp merging region and cover it in the proper direction.
Fast reconstruction of two-dimensional temperature distribution in participating medium
Authors: Liu Dong  , Wang Fei  , Huang Qun-Xing  , Yan Jian-Hua  , Chi Yong  , Cen Ke-Fa  ,   浙江大学能源清洁利用国家重点实验室，杭州  310027
Published: December 2020

An original model was presented for fast reconstruction of two-dimensional temperature distribution in participating medium using radiative information captured by charge-coupled device cameras. Compared with present models for temperature reconstruction, the model developed here is based on backward Monte Carlo method and reconstruction speed is faster, it is more efficient and can describe the scattering medium better. An exact two-dimensional temperature was assumed to be the reconstruction object and results show that even if there are measurement errors, the reconstructed temperature distribution can reproduce the original temperature distribution.
Electronic structure and optical properties of fluorite-structure TiO2
Authors: Guan Li  , Liu Bao-Ting  , Li Xu  , Zhao Qing-Xun  , Wang Ying-Long  , Guo Jian-Xin  , Wang Shu-Biao  ,   河北大学物理科学与技术学院，保定  071002
Published: December 2020

We calculated the band structure and density of states of fluorite type TiO2 using density functional theory. The results show that fluorite type TiO2 is an indirect-band-gap semiconductor, and its indirect band gap Eg=2.07eV is smaller than that of rutile or anatase TiO2. To make optical properties clear, we calculated the complex dielectric constant of fluorite-structured TiO2 and compared it with the rutile TiO2. The results illustrate that the fluorite TiO2 has a large static dielectric constant of 8.31, and ε1xy(0)=6.01 and ε1z(0)=7.07 for rutile TiO2 show excellent agreement with experimental data. Also, two new absorption peaks located at 51nm and 153nm respectively were observed and the absorption range of fluorite TiO2 extends to the visible region.
Measurement of single-electron transfer cross sections in collision of C3+ with neon at intermediate velocity
Authors: Liu Hui-Ping  , Chen Xi-Meng  , Liu Zhao-Yuan  , Gao Zhi-Min  , Liu Yu-Wen  , Du Juan  , Zhang Hong-Qiang  , Sun Guang-Zhi  , Wang Jun  , Xi Fa-Yuan  , Wang Yuan  ,   兰州大学核科学与技术学院,兰州  730000
Published: December 2020

Absolute cross sections for single-electron transfer of neon induced by C3+ at intermediate velocity (2.2v0—4.2v0) were measured and calculated using n-body classical trajectory Monte Carlo (nCTMC) method. Good overall agreement between experimental and nCTMC results is found. Screening effect, changes of the ionization potential and the effective charge are taken into account in interpreting the qualitative differences between theoretical and experimental results. In addition, the mechanism of transfer ionization is discussed briefly.
Density functional theory study of the stability, electronic and magnetic properties of Scn, Yn and Lan (n＝2—10) clusters
Authors: Li Xi-Bo  , Luo Jiang-Shan  , Guo Yun-Dong  , Wu Wei-Dong  , Wang Hong-Yan  , Tang Yong-Jian  ,   (1)内江师范学院物理系，内江  641112; (2)西南交通大学理学院，成都  610031; (3)中国工程物理研究院激光聚变研究中心，绵阳  621900
Published: December 2020

Several functionals combined with different basis sets have been examined for the Sc2, Y2 and La2 dimer by using density functional theory. Compared with previous theoretical and experimental data of dimers, the BP86/CEP121G level for Scn and Yn clusters, the PBE1PBE/LANL2DZ level for Lan (n=2—10) clusters were selected to investigate the geometry, stability, electronic and magnetic properties of these clusters. The relative stability of these clusters of the same group have the same results, which can be explained by the model with geometry of dense packing. The highest occupied molecular orbital—lowest unoccupied molecular orbital gap of Lan clusters are bigger than those of Scn and Yn clusters, and a relative bigger energy gap are found for the magic clusters with n=4, 7 and 9. The vertical ionization energy VIP and electron affinity were calculated, and the VIP is in good agreement with experiments for yttrium clusters. The static polarizabilities can characterize the stability of these clusters. Big and anomalous magnetic moments are discovered and are in agreement with the experiments for Scn, Yn and Lan clusters, but they decrease with the increasing of cluster size and have local oscillatory character.
Density functional theory study of ［Mg(NH2)2］n(n=1—5) clusters
Authors: Chen Yu-Hong  , Kang Long  , Zhang Cai-Rong  , Luo Yong-Chun  , Ma Jun  ,   (1)兰州理工大学甘肃省有色金属新材料重点实验室，兰州  730050; (2)兰州理工大学物理系，兰州  730050; (3)兰州理工大学物理系，兰州  730050；兰州理工大学甘肃省有色金属新材料重点实验室，兰州  730050
Published: December 2020

Possible geometrical structures and relative stabilities of ［Mg(NH2)2］n(n=1—5) clusters are studied by using the hybrid density functional theory (B3LYP) with 6-31G* basis sets. For the most stable isomers, the electronic structure, vibrational properties, bond properties and ionization potentials are analyzed. The calculated results show the following tendencies: the Mg and N atom are bonded with each other to form catenulate structures. The bond lengths for ［Mg(NH2)2］n (n=1—5) clusters are about 0.190—0.234nm for Mg—N, and 0.101—0.103 nm for the N—H bonds, the bond angles of H—N—H are about 100.2°—107.5°. The population analysis suggests that the natural charge of N atoms are about -1.551e—-1.651e, that of Mg atoms are about 1.585e—1.615e, that of H atoms are about 0.369e—0.403e, and that of—NH2 are about -0.784e—-0.845e, and the bonds between Mg and —NH2 have strong ionicity. The comparative study of structures and spectra of clusters and crystal show that —NH2 keeps the integrity in the crystal and in clusters.
Study on the near field modulation and laser induced damage of beam sampling grating
Authors: Yao Xin  , Gao Fu-Hua  , Li Jian-Feng  , Zhang Yi-Xiao  , Wen Sheng-Lin  , Guo Yong-Kang  ,   (1)成都精密光学工程研究中心，成都  610041; (2)四川大学物理科学与技术学院，成都  610064
Published: December 2020

The beam sampling grating (BSG) is one kind of important diffractive optical elements which is used in sampling and diagnosis. In terminal optical system of the inertial confinement fusion (ICF) system, the modulation produced by strong laser in the near field, may cause laser induced damage to the BSG. It makes the element work abnormally. In order to provide the theoretical basis for protecting this kind of optical element from laser induced damage under the strong laser condition, this paper uses the Fourier modal theory to carry on the numerical simulation of the interior modulation for BSG in near field. The results indicate that the interior modulation of BSG is weak, but the optical field distribution is still not even, thus in these areas the damage probability is higher than in other positions. Moreover, through the fabrication error analysis of BSG, the relationship between modulation in near field and fabrication error was obtained. The computed results indicate that the depth error and the duty cycle error of grooves affect the modulation of the light beam in near field, but the influence of groove depth error is larger than the duty cycle error. However, if the groove depth error does not exceed a definite value, its modulation also remains on a lower level. Therefore the BSG can still work in the ICF driver normally.
Multilayer dielectric thin film reflector for spectrum reshaping of chirped pulse laser in Nd:glass chirped pulse amplification system
Authors: Li Ming  , Zhang Bin  , Dai Ya-Ping  , Wang Tao  , Fan Zheng-Xiu  , Huang Wei  ,   (1)上海激光等离子体研究所，上海  201800; (2)四川大学电子信息学院，成都  610064; (3)四川大学电子信息学院，成都  610064；上海激光等离子体研究所，上海  201800; (4)中国科学院光电技术研究所，成都  610209; (5)中国科学院上海光学精密机械研究所，上海  201800
Published: December 2020

In order to compensate for the gain narrowing and gain saturation effects, and also to improve the signal to noise ratio of the output high-power laser pulse, lots of attention have been paid to the spatial distribution, the temporal profile, as well as the spectrum reshaping in the design of kilo-joule peta-watt chirped pulse amplification (CPA) systems. In this paper, a new method for the spectrum reshaping is proposed, which utilizes a multilayer dielectric thin film reflector with specific construction to realize the spectrum reshaping of the chirped pulse laser in large energy and high power Nd:glass CPA system. The results show that the reflectivity distribution of the multilayer dielectric film reflector can be controlled effectively only if the parameters of the thin film reflector are chosen appropriately. The spectrum modulation radio can be varied over 60% under the condition that the phase of the reflecting light remains nearly constant. The thin film reflector designed for spectrum reshaping of the Nd:glass CPA system with the central wavelength of 1053nm exhibits a bandwidth of reflect light of 196nm, the chromatic resolving capability of about 0.1nm and the phase aberration in the range of the tens of nanometer of up to 12mrad, which can meet the requirement of the “Senguang-Ⅱ” kilo-joule peta-watt reconstruction project.
Composite coherence vortices in the superimposed field of partially coherent vortex beams and their propagation dynamics
Authors: Cheng Ke  , Yan Hong-Wei  , Lü Bai-Da  ,   四川大学激光物理与化学研究所，成都  610064
Published: December 2020

The composite coherence vortices formed by superimposing two parallel, off-axis partially coherent flattened vortex beams are studied in detail. It is shown that the number and position of composite coherence vortices depend on the beam order, relative off-axis distance and coherence parameter, as well as on the free-space relative propagation distance. The “hidden" composite coherence vortex in the partial coherence regime corresponds to its counterpart——the composite optical vortex in the full coherence regime. In the coherent limit the composite coherence vortex evolves into the composite optical vortex.
The comparison of steady-state gain of V-type and Λ-type atomic systems of lasing without inversion
Authors: Chang Zeng-Guang  , Liu Jian-Cheng  , Yan Ke-Zhu  ,   (1)德州学院物理系，德州  253022; (2)曲阜师范大学物理工程学院，曲阜  273165
Published: December 2020

In this paper we study the dependence of steady-state gain of a closed V-type atomic system and a closed Λ-type atomic system of lasing without inversion on the detuning of the coherence lasers under the condition that the corresponding parameters of the two atomic systems are equal. By the way of numerical simulation and comparison, we find that the curves of probe-laser gain of the two atomic systems versus the detuning of probe-laser have similar shapes but their values are different, which are related to the characteristics of atomic coherence and population distribution of the two atomic systems directly. In addition, we find that the driving laser deturning and the additional atomic coherence caused by spontaneously generated coherence can exert a great influence upon the probe-laser gain.
Influence of negative refractive index materials on repulsive Casimir forces
Authors: Zeng Ran  , Yang Ya-Ping  , Liu Shu-Tian  ,   (1)哈尔滨工业大学应用物理系，哈尔滨  150001; (2)哈尔滨工业大学应用物理系，哈尔滨  150001；同济大学物理系，上海  200092; (3)同济大学物理系，上海  200092
Published: December 2020

The influence of negative refractive index materials on repulsive Casimir forces is studied. The repulsive Casimir interaction is determined by the electric and magnetic properties of the material slabs and the intermediate medium. Through theoretical analysis and numerical calculation, the condition for obtaining repulsive forces is presented. For the negative refractive index materials described by dispersive permittivity and permeability of Drude-Lorentz type, repulsive Casimir force can be realized by tuning the characteristic frequencies.
Investigation on a TEM00-mode dynamic stable resonator with two Nd:YAG rods
Authors: Liu Chong  , Ge Jian-Hong  , Xiang Zhen  , Chen Jun  ,   浙江大学现代光学仪器国家重点实验室，杭州  310027
Published: December 2020

In order to achieve high power, high brightness lasers, a TEM00-mode dynamic stable resonator with two Nd:YAG rods is constructed. The thermal induced birefringence is compensated by two identically pumped rods. The laser output 61W is achieved in cw mode under lamp pumped regime. The influence of the cavity parameters on the laser output properties is investigated using the equivalent thermal lens method. It turns out that the distance of the output coupler and the high reflectivity mirror from the laser rods play different roles on the laser properties.
Study of imaging system based on the tunable terahertz wave source with quasi-Gaussian beam output
Authors: Zhang Xian-Bin  , Shi Wei  ,   西安理工大学应用物理系，西安  710048
Published: December 2020

A terahertz wave imaging system based on the tunable terahertz source with the quasi-Gaussian beam output is reported. In this imaging system, terahertz wave beam is easy to be focused and transmitted owing its spatial distribution with the excellent beam quality factor of M2x＝1.15 and M2z＝1.25. The experimental results show the spatial resolving power of this imaging system is close to the typical terahertz wavelength of 250μm. In the output range of 1.0—2.5THz, the signal to noise ratio (SNR) is higher than 1000dB, and the SNR is above 6000dB at 1.8THz. Based on this system, the terahertz imaging experiments for the several samples were performed, and clear pictures were obtained.
Brillouin-enhanced nondegenerate four-wave mixing
Authors: Liu Xia  , Niu Jin-Yan  , Sun Jiang  , Mi Xin  , Jiang Qian  , Wu Ling-An  , Fu Pan-Ming  ,   (1)河北大学物理科学与技术学院，保定  071002; (2)中国科学院物理研究所北京凝聚态物理国家实验室，北京  100190
Published: December 2020

We have observed Brillouin-enhanced nondegenerate four-wave mixing (NFWM) induced by an acoustic wave and Rayleigh-type NFWM induced by molecular reorientation in CS2. It was found that the acoustic wave and the molecular reorientation grating are not mutually independent. The existence of the acoustic wave destroys the phase coherence between the polarizations of the Rayleigh-type NFWM and the Brillouin-enhanced NFWM.
The design of left-handed metamaterials composed of magnetic resonators and electric resonators
Authors: Wang Jia-Fu  , Qu Shao-Bo  , Xu Zhuo  , Zhang Jie-Qiu  , Yang Yi-Ying  , Ma Hua  ,   (1)空军工程大学理学院，西安  710051; (2)空军工程大学理学院，西安  710051；西安交通大学电子陶瓷与器件教育部重点实验室，西安  710049; (3)西安交通大学电子陶瓷与器件教育部重点实验室，西安  710049
Published: December 2020

In designing left-handed metamaterials composed of magnetic resonators and electric resonators, two design principles, that is, the single-loop mirror-symmetry design principle and double-loop (quadruple-loop) mirror-symmetry design principle, were respectively proposed for the design of magnetic resonators and electric resonators. Based on the two principles, new structures with simultaneously negative permeability and permittivity were designed. By means of simulation experiments, the double-negative property of the proposed structure as well as the two design principles was verified. The two design principles and structures proposed in this paper are of great practical values in designing new types of left-handed metamaterials.
Simulation research on the law of flow of liquid metal in micro-channels
Authors: Ren Ming-Xing  , Li Bang-Sheng  , Yang Chuang  , Fu Heng-Zhi  ,   (1)哈尔滨工业大学材料科学与工程学院,哈尔滨  150001；哈尔滨工业大学微纳米技术研究中心,哈尔滨  150001; (2)哈尔滨工业大学微纳米技术研究中心,哈尔滨  150001
Published: December 2020

We modified the traditional Navier-Stokes equation, and used the Fluent software to simulate the microscopic law of flow of Zn-Al alloy melt in the micro-channel. The simulation results show that when the diameter of the channel is 0.5mm， the liquid metal in the micro-channel is in a critical state. Relative thickness of boundary-velocity layer increases with the decrease of diameter of the channel, and micro-channel flow shows obvious convex-front effect, which has not been observed in the macroflow. The convex-front effect weakens when the inlet pressure increases. Between the flow front and upstream region, there exist negative pressure gradient zones, which become more outstanding in finer channels.
Numerical simulation on the energy deposition of double-layer target irradiated by intense pulsed ion beam
Authors: Gong Ye  , Zhang Jian-Hong  , Wang Xiao-Dong  , Wu Di  , Liu Jin-Yuan  , Liu Yue  , Wang Xiao-Gang  , Ma Teng-Cai  ,   (1)大连理工大学三束材料改性国家重点实验室,大连  116024; (2)大连理工大学三束材料改性国家重点实验室,大连  116024；大连工业大学信息科学与工程学院,大连  116034
Published: December 2020

Gaussian distribution models of voltage wave form of magnetically insulated diode (MID) of TEMPⅡ accelerator and intense pulsed ion beam (IPIB) density near the MID focus region have been built according to the results of experiments. Interaction of IPIB with a double-layer aluminum target coated by a thin film of gold has been studied using Monte Carlo method. The spatial and temporal evolution of deposited energy is obtained, the states of deposited energy for the different gold thickness are discussed, and the enhanced adhesion at interfaces by IPIB is investigated.
Sheath structure of a magnetized plasma
Authors: Zou Xiu  , Liu Hui-Ping  , Gu Xiu-E  ,   大连交通大学理学院，大连  116028
Published: December 2020

The structure of plasma sheath in an oblique magnetic field is numerically investigated by using fluid dynamics method. The simulation results reveal that the magnetic field has significant effects on the plasma sheath. Especially, the ion density distribution near the sheath edge changes obviously. Two cases of ion incidence are considered here. The action states of ions are more complicated when the ions enter the sheath with an oblique incidence angle. Under suitable conditions, Lorentz force induces fluctuations in the ion density. Ions could gather in some regions.
Study on the optical absorption of gold nanoshells by Mie theory
Authors: Wu Da-Jian  , Liu Xiao-Jun  ,   南京大学电子科学与工程系，近代声学教育部重点实验室，南京  210093
Published: December 2020

The variations of optical absorption of gold nanoshells with the shell thickness, size of the core, and core dielectric constant have been investigated by means of Mie theory. It was found that with the increase in the thickness of the shell, the strength of absorption peak increases first and then decreases. We also observed that with increasing core size the maximum optical absorption of the particles decreases. Furthermore, the increase of the core dielectric constant reduces the strength of absorption peak and the hollow gold nanoshells have the maximum optical absorption. We ascribe the change of the absorption peaks to the plasmon hybridization and the competition between the variations of conduction and oscillation electrons.
Influences of substrate temperature on crystalline characteristics and mechanical properties of SiNx films deposited by microwave electron cyclotron resonance magnetron sputtering
Authors: Ding Wan-Yu  , Xu Jun  , Lu Wen-Qi  , Deng Xin-Lu  , Dong Chuang  ,   (1)大连交通大学材料科学与工程学院，光电材料与器件研究所，大连  116028；大连理工大学三束材料改性国家重点实验室，大连  116024; (2)大连理工大学三束材料改性国家重点实验室，大连  116024
Published: December 2020

Hydrogen-free SiNx films were deposited at substrate temperature ranging from room temperature to 700℃ by microwave electron cyclotron resonance plasma enhanced unbalanced magnetron sputtering system. We have studied the influence of substrate temperature on the structural characteristics of deposited films including growth rate, microstructure, grain size, and hardness by using transmission electron microscopy, Fourier-transform infrared spectroscopy, and nano-indentation. The results indicate that the films deposited at room temperature are amorphous, and α-Si3N4 grains with random epitaxial sizes appear when substrate temperature is higher than 300℃. The α-Si3N4 grain size increases with substrate temperature up to 620℃, and then decreases at 700℃. At 700℃, the grains have uniform epitaxial sizes, and value of the film hardness reaches the maximum (36.7GPa).
Influence of layers’ mutual effect and radius on electronic energy of spherical nanometric system
Authors: Wu Qiang  , Zheng Rui-Lun  ,   (1)西南大学物理科学与技术学院,重庆  400715; (2)重庆文理学院物理与信息工程系,重庆  402160
Published: December 2020

On the basis of interaction between layers, the physical model of the bilayer spherical namometric system have been worked out. With the Green function method and Fourier transform, the electronic potential energy has been figured out for the system. In the example of HgS/CdS spherical nanometric system, the effect of system size and the layers' mutual effect has been discussed in terms of the electronic potential energy. The results show that: the layers' mutual effect could make the average height of the electronic potential barrier of the spherical namometric system lower; the more the layers' mutual effect is, the lower the height of the electronic potential barrier is, and the greater the undulation of the electronic potential energy curve is. For the same layers' mutual effect, electronic ground state energy and revised energy by layers' mutual effect will be reduced with the increase of particle radius; but for the same size, the revised energy by layers' mutual effect will increase with the increase of the layers' mutual effect.
Influence of annealing on the properties of Mn and N co-doped Zn0.88Mn0.12O:N films
Authors: Qiu Dong-Jiang  , Wang Jun  , Ding Kou-Bao  , Shi Hong-Jun  , Jia Yin  ,   (1)浙江大学物理系，杭州  310027; (2)浙江大学信息与电子工程学系，杭州  310027
Published: December 2020

Mn and N codoped ZnO (or Zn1-xMnxO:N) films were grown on Si(001) and quartz substrates via reactive electron beam evaporation in the NH3 atmosphere. The growth temperature was 300℃. The as-grown Zn0.88Mn0.12O:N film was cut into two pieces and one of them was then annealed in O2 atmosphere at 400℃ for 30 min. X-ray diffraction measurements reveal that Zn0.88Mn0.12O or Zn0.88Mn0.12O:N films have the single-phase wurtzite structure. The (002) diffraction peak of Zn0.88Mn0.12O:N film is located at a smaller angle and has a wider line width compared with that of Zn0.88Mn0.12O film. Hall measurement shows that the as-grown Zn0.88Mn0.12O:N film is the n-type and changes to p-type after annealing. DC magnetization analysis shows that the as-grown Zn0.88Mn0.12O:N films are ferromagnetic at room temperature (RT) but the ferromagnetism (FM) is weak and unstable. However, the FM of Zn0.88Mn0.12O:N film at RT is remarkably enhanced and its stability efficiently improved by annealing in O2 atmospher. The origin of FM of Zn0.88Mn0.12O:N film at RT, as well as the mechanisms of its FM enhancement and stability improvement by annealing are discussed.
The formation of vertical Bloch line in the garnet bubble films subjected to pulsed bias field
Authors: Hu Yun-Zhi  , Sun Hui-Yuan  ,   河北师范大学物理科学与信息工程学院，石家庄  050016
Published: December 2020

We studied experimentally the dynamic characteristics of hard domains produced in the garnet bubble films at different pulse widths. The results show that the dumbbell domains contracted from multi-branched domains at zero static bias field rotate clockwise， independent of the pulse width of the pulsed bias field in which the multi-branched domains were produced. In the direct current fixed bias fields， soft domain segments harden and become dumbbell domains. How the dumbbell domains rotate is dependent on the pulse widths of the hardening pulsed bias field applied in the experiment. The results show that all the dumbbell domains rotate anticlockwise when the pulse width is narrow， and they rotate clockwise and anticlockwise simultaneously and then they all rotate clockwise as the width of hardening pulse becomes wider and wider. It reveals that the direct current bias field and pulsed bias field have great influence on the types of vertical Bloch line in the garnet bubble films.
Role of Dy addition in rapid-quenched NdFeB permanent magnets
Authors: Zhang Ran  , Liu Ying  , Gao Sheng-Ji  , Xie Zhi  , Tu Ming-Jing  ,   (1)四川大学材料科学与工程学院，成都  610064; (2)中国科学技术大学国家同步辐射实验室，合肥  230029
Published: December 2020

Following the previous study on the effect of Nb addition in rapid-quenched (Nd,Dy)11.5Fe82.4-mNbmB6.1 permanent magnets on the magnetic properties, temperature characteristics and microstructure, the role of Dy addition in rapid-quenched Nd11.5-nDynFe81.4Nb1B6.1 (n＝0,0.5,1,1.5,2) permanent magnets has been investigated. It was found that Hci increases with increasing Dy content and the irreversible loss of magnetic flux decreases. Dy addition results in smaller grains and more homogeneous and regular grain structure. It is considered that Dy addition may enhance exchange coupling pining field and reduce the internal stray magnetic field. As a result, the irreversible loss of magnetic flux decreases notably and the magnetic properties at higher temperature are improved. Dy atoms on entering the main lattice of Nd9.5Dy2Fe81.4Nb1B6.1 alloy cause crystal lattice distorsion and affect the local structure of Fe atoms; however, Dy atoms have little influence of the local structure of Nd atoms.
Study on equivalent electromagnetic parameters and absorbing properties of honeycomb-structured absorbing materials
Authors: He Yan-Fei  , Gong Rong-Zhou  , Wang Xian  , Zhao Qiang  ,   华中科技大学电子科学与技术系，武汉  430074
Published: December 2020

Based on strong interference theory and the assumption of long wave band，formulae for computing the equivalent electromagnetic parameters of honeycomb-structured absorbing materials are presented. It is pointed out that the equivalent permeability and permittivity of honeycomb-structured absorbing materials are smaller than those of the absorbing layer， but the equivalent permittivity is reduced more significantly， so the equivalent permeability is more close to the equivalent permittivity. This is helpful for the design of impedance matching of absorbing materials. It is indicated by reflectivity results that the absorbing layer should have an optimum thickness to make the reflectivity minimal for honeycomb-structured absorbing materials with different height of honeycombs. These results are useful for design of honeycomb-structured absorbing materials.
Spectral characteristics and crystal field parameters of the Cr3+ doped Cd3Al2Ge3O12
Authors: Yuan Jian-Hui  , Yang Chang-Hu  , Zhang Zhen-Hua  , Yuan Xiao-Bo  ,   (1)长沙理工大学电气与信息工程学院，长沙  410076; (2)长沙理工大学物理与电子科学学院，长沙  410076
Published: December 2020

Polycrystalline Cd3Al2Ge3O12：Cr3+ was synthesized by high temperature solid-state method. Its crystal structure was analyzed by X-ray diffraction. Based on its absorption spectrum at room temperature and the emission spectra at room temperature and 77K， the spectral properties were investigated and the crystal field parameter was calculated. The results show that under the excitation of 450nm light， the emission spectrum of Cd3Al2Ge3O12：Cr3+ at room temperature mainly consists of three broad bands with a weak R line. The three broad bands correspond to 4T1→4A2， 2T2→4T2， and 4T2→4A2 transitions of Cr3+， respectively. The broad band emissions weaken and the R line becomes stronger and sharper at low temperature. The calculated results showed the crystal field strength Dq/B=2.32， Stokes displacement ΔES=1919cm-1 and Huang-Rhys factor S=5.58， which indicates that Cr3+ in Cd3Al2Ge3O12 garnet are located in a weak crystal field strength and the coupling between the electrons and the phonons is strong， The distance ΔE between 4T2 zero phonon energy level and 2E energy level is only 326.5cm-1， which is beneficial to the output of Cr3+ tunable laser.
Investigation on the effect of lamellar thickness on three-dimensional lamellar eutectic growth by multi-phase field model
Authors: Yang Yu-Juan  , Wang Jin-Cheng  , Zhang Yu-Xiang  , Zhu Yao-Chan  , Yang Gen-Cang  ,   西北工业大学凝固技术国家重点实验室，西安  710072
Published: December 2020

Using the multi-phase field model proposed by Kim， Kim， Suzuki and Ode (KKSO)， numerical studies have been carried out to investigate the effect of lamellar thickness on the lamellar eutectic growth in three dimensions. Simulation results showed that the lamellar thickness has significant effects on the eutectic morphology evolution with a given lamellar spacing. When the lamellar thickness is comparatively small， the eutectic lamellar growth is similarly to the two-dimensional case. Increasing the lamellar thickness， the effect of lamellar thickness becomes stronger， as a result， the lamellar structure distorts vertically， and oscillations on both the direction of the width and the direction of the thickness occur alternatively after a further increase of the lamellar thickness. When the lamellar thickness is bigger than the lamellar width， a stronger oscillation in the thickness direction than that in the width direction occurs， and eventually the oscillation in the width direction is suppressed but only an approximate 1λ oscillation in the thickness direction can be found. Moreover， simulation results also showed that the change of undercooling is consistent with the morphology transition.
Effects of organic adsorbent on the photoluminescence of porous silicon microcavities
Authors: Liu Guang-You  , Tan Xing-Wen  , Wang Zhen  , Yao Jin-Cai  , Xiong Zu-Hong  ,   西南大学物理科学与技术学院，重庆  400715
Published: December 2020

The effects of organic absorbent on the refractive index and photoluminescence of porous silicon microcavities were theoretically investigated by using the Bruggeman effective medium approximation. Experimentally， porous silicon microcavities were fabricated by computer controlled electrochemical etching， and then interacted with the molecules of oil vapor from a rotary pump. We found that the narrow photoluminescence spectra of porous silicon microcavities were sensitive to the adsorption and de-adsorption of the oil vapor molecules， which leads to a 71nm red-shift and the intensity variation in photoluminescence spectrum. The experimental results are qualitatively consistent with the theoretical estimate.
Multi-angular polarized characteristics of cirrus clouds
Authors: Cheng Tian-Hai  , Gu Xing-Fa  , Chen Liang-Fu  , Yu Tao  , Tian Guo-Liang  ,   (1)中国科学院遥感应用研究所遥感科学国家重点实验室，北京  100101；国家航天局航天遥感论证中心，北京  100101; (2)中国科学院遥感应用研究所遥感科学国家重点实验室，北京  100101；中国科学院研究生院，北京  100049；国家航天局航天遥感论证中心，北京  100101
Published: December 2020

Cirrus is mainly composed of non-spherical ice crystals in various shapes and plays an important roles in Earth's radiation budget and global climate change. Knowledge of cirrus properties is crucial for studying the radiation budget and climate change. Thus studies of the optical， microphysical， and physical properties of cirrus have become the popular issue. The optical properties of cirrus at 0.865μm are studied. And the reflectance and polarized reflectance are evaluated with the adding-doubling method by solving the vector radiative transfer model， and the sensitivity of reflectance and polarized reflectance to cirrus optical parameters and surface albedo are evaluated. The results indicate that the polarized reflectance over a large range of scattering angles can show the information of cirrus properties. Based on the studies of the sensitivity， the basic theory of using the remote sensing data of multi-angular polarized measurements to retrieve the properties of cirrus is proposed.
Conformal invariance and conserved quantity of Lagrange systems under Lie point transformation
Authors: Cai Jian-Le  , Mei Feng-Xiang  ,   (1)北京理工大学理学院，北京  100081; (2)杭州师范大学理学院，杭州  310018；北京理工大学理学院，北京  100081
Published: December 2020

Conformal invariance and conserved quantities of Lagrange system under Lie point transformation are studied. Firstly, the definition of conformal invariance and determining equation for the Lagrange system are provided. Secondly, the relationship between the system’s conformal invariance and Lie symmetry are discussed; the necessary and sufficient condition on which the system’s conformal invariance would be Lie symmetry under the infinitesimal one-parameter point transformation group is deduced; and the conserved quantities of the system are given. Lastly, an illustration example is introduced.
Design and assembly of split-sphere high pressure apparatus based on the hinge-type cubic-anvil press
Authors: Wang Fu-Long  , He Duan-Wei  , Fang Lei-Ming  , Chen Xiao-Fang  , Li Yong-Jun  , Zhang Wei  , Zhang Jian  , Kou Zi-Li  , Peng Fang  ,   四川大学原子与分子物理研究所，成都  610065
Published: December 2020

A new split-sphere large-volume high pressure apparatus has been developed to generate high pressure above 10 GPa. The apparatus is based on a domestic hinge-type cubic-anvil press known as the DS6×800T press. In this work, the split-sphere parts are directly placed in the cubic-anvil cell, and the effect of the gasket dimension and phyrophyllite density on pressure transmitting efficiency has been investigated. The relationship of cell pressure versus press load was calibrated at room temperature for the 14/8 (octahedral edge-length/anvil truncation edge-length, in millimeters) cell assembly using the phase transitions of Bi Ⅰ-Ⅱ(2.55 GPa), Ⅲ-Ⅴ(7.7 GPa), and SnⅠ-Ⅱ(9.4 GPa).The experimental results show that the cell pressure can reach about 10 GPa with a sample volume of 3—4 mm3 under an applied load of 290 ton.
Exact calculation of the optical path difference and lateral displacement of modified large optical path difference Sagnac interferometer in full view field used in upper atmospheric wind field measurement
Authors: Ruan Kai  , Zhang Chun-Min  , Zhao Bao-Chang  ,   (1)西安交通大学理学院，西安  710049; (2)西安交通大学理学院，西安  710049；宁波工程学院理学院，宁波  315016; (3)中国科学院西安光学与精密机械研究所空间光学研究室，西安  710068
Published: December 2020

The shearing principle of modified large optical path difference Sagnac interferometer for upper atmospheric wind field measurement is presented. The exact expression of the optical path difference and lateral displacement in the full view field of modified Sagnac interferometer are calculated by analysing the relation between space beeline and its projection and the notion of ray index at random incidence angle. The theoretical and practical guidance are thereby provided for the study and design of the spatially modulated interference imaging spectrometers.
Isospin effect of nucleon-nucleon cross section on the isoscaling parameter α
Authors: Liu Jian-Ye  , Guo Wen-Jun  , Zuo Wei  , Lee Xi-Guo  ,   (1)上海理工大学科学学院，上海  200093; (2)天水师范学院数理和信息学院，天水  741000；中国科学院近代物理研究所，兰州  730000；兰州重离子加速器国家实验室原子核理论中心，兰州  730000; (3)中国科学院近代物理研究所，兰州  730000；兰州重离子加速器国家实验室原子核理论中心，兰州  730000
Published: December 2020

The isospin effects of isoscaling parameter α on the nucleon-nucleon cross section are investigated for two couples of central nuclear reactions 40C+ 40Ca with 60Ca + 40Ca and 112Sn+ 112Sn with 124Sn+ 124Sn within an isospin dependent quantum molecular dynamics. It is found that the isospin effect of isoscaling parameter α on the isospin dependent nucleon-nucleon cross section σmedNN(αm) compared with that on the isospin independent nucleon-nucleon cross sections σ1NN(αm) is very obvious. However, the isospin effect of isoscaling parameter α on σmedNN(αm) compared with that on the isospin independent nucleon-nucleon cross section σ2NN(αm) is small. The mechanisms for the above difference are investigated in detail.
Study on charge transport properties of hexaazatriphenylene and its derivatives
Authors: Hu Jing-Dan  , Cai Jing  , Chen Jun-Rong  , Li Quan  , Zhao Ke-Qing  ,   四川师范大学化学与材料科学学院，成都  610066
Published: December 2020

The structure optimization and frequency calculation of hexaazatriphenylene, triphenylene and their derivatives were carried out at the level of B3LYP/6-31G**, and the most stable configurations were obtained. On the basis of the most stable geometries, the relationships of the total energy with rotation degrees between the dimers were studied, and the lowest energy point was obtained. Based on the semi-classical model of the charge transport, our results predict that hexaazatriphenylene molecules have the largest positive charge transport rate and the smallest negative charge transport rate. Introduction of SH, OH, OR and F groups make the positive charge transport to increase, and the negative charge transport to decrease. The length of alkoxy group has little effect on charge transport properties.
Collimation of chromium beam by one-dimensional doppler laser with large collimating slit
Authors: Zhang Bao-Wu  , Zhang Wen-Tao  , Ma Yan  , Li Tong-Bao  ,   (1)同济大学物理系，上海  200092; (2)同济大学物理系，上海  200092；桂林电子科技大学电子工程系，桂林  541004
Published: December 2020

In this paper, we present experimental study of effects of laser power and interaction length on collimation of chromium atomic beam by one-dimensional Doppler laser with large collimating slit of 5 mm in length, where the fluorescence is treated by Matlab. In addition, calculation by an adaptive step size, fourth-order Runge-Kutta type algorithm is done corresponding to the experiment. Both results show that with fixed interaction length, when the laser power becomes larger, or with fixed laser power, when the interaction length becomes longer, the FWHM of collimated atomic beam becomes smaller, and the peak becomes higher.
Retrieval of the optical thickness and effective radius of aerosols from reflected solar radiation measurements
Authors: Sun Xian-Ming  , Ha Heng-Xu  ,   山东理工大学电气与电子工程学院电子信息科学系,淄博  255049
Published: December 2020

A method for determining the optical thickness and effective particle radius of spherical aerosols with sun light of a single wavelength is presented. Based on the vector radiative transfer theory, the reflection matrix of the aerosols is calculated by using the adding-doubling method for λ=0.75μm and 3.3μm, the effective radii of aerosol particles were 0.01—1.5μm, and the optical thickness were 0.05—1. We modeled the retrieval process by computer simulation. From the numerical results, we conclude that the radiance combined with polarization is capable of uniquely retrieving optical thickness and effective radius with high accuracy. Especially, when the effective radius is less than 0.4μm, a visible light wavelength can be used for retrieval; when the effective radius is larger than 1.0μm, an infrared light wavelength can be used for retrieval; when the effective radius lies between 0.4 and 1.0μm, both of the two wave bands can be used to obtain a unique result with high accuracy.
Dynamic properties of photoinduced anisotropy of diarylethene
Authors: Chen Li-Ju  , Yao Bao-Li  , Han Jun-He  , Gao Peng  , Chen Yi  , Wang Ying-Li  , Lei Ming  ,   (1)中国科学院理化技术研究所，北京  100080; (2)中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室，西安  710119; (3)中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室，西安  710119；中国科学院研究生院，北京  100049
Published: December 2020

A theoretical model has been put forward to describe the dynamic properties of photoinduced anisotropy in photochromic diarylethene/PMMA film. The kinetic curves of molecule concentration, photoinduced dichroism and birefringence are calculated under the condition of excitation by linearly polarized light. The results show that the color molecule concentration decreases with the increase of the excitation exposure until the saturation point is reached. The photoinduced anisotropy increases to a maximum and then decreases with the exposure increasing. The optimal exposure is 260 J/cm2. Using the orthogonal polarization detection, the transmittance of probe beam reflecting the anisotropy is measured. The experimental result and the theoretical calculation are essentially consistent.
The diffraction effect in a thermal imaging system with a front wire grid
Authors: Liu Bin  , Jin Wei-Qi  , Dong Li-Quan  ,   北京理工大学信息科学技术学院光电工程系，北京  100081
Published: December 2020

According to the affected images generated by the thermal imaging system which incorporates a front wire grid, with the help of classical optical theory, we analyzed the diffractive functional principle character of light wave, and also analyzed the case of non-concolorous targets, and further established the mathematic model. The results indicated that after putting in parameters of real instance and generating simulated images using MATLAB, the simulated images have good comparability with the images obtained in reality. The research achieved the expected aim of the modelling. Finally we put forward the questions and key technology pending further research.
New method of decoy state quantum key distribution with a heralded single-photon source
Authors: Quan Dong-Xiao  , Pei Chang-Xing  , Zhu Chang-Hua  , Liu Dan  ,   西安电子科技大学综合业务网国家重点实验室,西安  710071
Published: December 2020

We propose a new method of decoy state quantum key distribution with a heralded single-photon source. Alice uses the parametric down-conversion to generate entangled photon-pairs, one of the pair is used as heralding photon. According to the results of the trigger detector the heralded photons are divided into trigger and non-trigger sets.The states of the photons in the trigger set are used as the signal states and the ones in the non-trigger sets are used as the decoy states. Because of the efficiency of the trigger detector, the two sets both have photons. The yield and error rate of the single-photon are estimated through the yield and error rate of the two sets. This method does not need changing the intensity of the photon source, is easy to implement. Analysis results show that this method can reach the same security distance as with a perfect single photon source; the key generation rate is increased a lot compared with the method with a heralded photon source and is approximately two thirds the rate of the three intensities decoy state quantum key distribution with a heralded photon source.
Effect of ionization and recombination between excited states on gain of 19.6nm X-ray laser
Authors: Qiao Xiu-Mei  , Zheng Wu-Di  , Zhang Guo-Ping  ,   北京应用物理与计算数学研究所，北京  100088
Published: December 2020

As it is difficult to solve a large number of rate equations including doubly excited states of various ions, block matrix method is expected to dramatically reduce the machine time by dividing the large number of equations into pieces of small units, and solving them one by one, on condition that the ionization and recombination between excited states of ions can be ignored. In this paper, the influence of ionization and recombination between excited states on plasma status was studied, and detailed analysis of its mechanism was made. The effect on gain of Ne-like Ge 19.6nm X-ray laser respectively driven by 1.0ns pulse, 100ps pulse and 5ps pre-pulse and main pulse was studied. The simulation shows that for the 5ps driving pulse case, the ionization and recombination between excited states has relatively large influence, and it can not be ignored and that for the two quasi-stable state cases, in the gain region with electron density less than 5×1020cm－3, the FWHM temporal width of gain increases by～10%, and the FWHM spatial width of gain increases respectively by～13% and ～-23%, and the time the peak gain appears is delayed respectively by～1.4% and ～6.9%, which is tolerable, implying that the block matrix method could be applied in the qualitative modeling of QSS scheme X-ray laser. However, for accurate study, the ionization between the excited states could not be neglected.