bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on phase relations, crystal structure and magnetic properties of Ti1－xCrxO2±δ system
Authors: Li Jian  , Song Gong-Bao  , Wang Mei-Li  , Zhang Bao-Shu  ,   (1)西南科技大学材料科学与工程学院,绵阳 621010; (2)西南科技大学材料科学与工程学院,绵阳 621010；Department of Ceramics and Glass Engineering,University of Aveiro,Aveiro 3810-193，Portugal
Published: December 2020

A series of samples of Ti1-xCrxO2±δ were prepared by Sol-Gel process. The particle size, morphology, valence, solid solution range, phase relations and magnetic properties of Ti1-xCrxO2±δ samples were studied by XRD, SEM, XPS and SQUID measurements. Meanwhile, the Rietveld refinement method was employed to study the effect of Cr doping on the crystal structure ofTiO2. The results show that the solid solution range of both Ti1-xCrxO2±δ systems annealed at 1000℃ are x＝0—0.03. Their lattice parameters decrease with increasing Cr concentration. The results of both XRD analysis and magnetic measurements show that the solid solution range of both Ti1-xCrxO2±δ systems annealed at 1000℃ are x＝0—0.02. Cr ions of samples sintered at 500℃ and 1000℃ have two chemical states, Cr+3 and Cr+6， respectively, while the samples　sintered at 1000℃ have much greater Cr+6 content than the ones at 500℃. According to the results of M-H and M-T measurements, magnetic properties of Ti1-xCrxO2±δ samples sintered at 500 ℃ with x=0—0.02 are ferromagnetic. When x≥0.04, they consisted of both ferromagnetic phase and paramagnetic phase. They have stronger ferromagnetic properties at low temperature (50K). The paramagnetic phase is the main constituent and the ferromagnetic phase has less volume fraction at room temperature.
Using BCP layer to control the chroma of white phosphorescent organic light-emitting device
Authors: Zhang Guo-Hui  , Hua Yu-Lin  , Wu Kong-Wu  , Wu Xiao-Ming  , Yin Shou-Gen  , Hui Juan-Li  , An Hai-Ping  , Zhu Fei-Jian  , Niu Xia  ,   天津理工大学材料物理研究所，天津市光电显示材料与器件重点实验室，天津 300384
Published: December 2020

Three types of double emitting layer white organic light-emitting devices (POLEDs) were fabricated. The efficiency of the device can be increased largely by the introduction of phosphorescent dye (Ir(ppy)3) and the chroma of the device can be tuned by inserting a BCP layer between the two light-emitting layers. The device with the configuration of: ITO/PVK:NPB (30nm)/BALq:3.0 wt%TBPe(30nm)/BCP(5.0nm)/CBP:5.0 wt%Ir(ppy)3:2.0 wt%rubrene(15nm)/BCP(10nm)/Mg:Ag shows white emission and high efficiency. A white light with Commission Internationale de l'Eclairage (CIE) coordinates of (0.31, 0.37) and brightness of 4670 cd/m2 are obtained at 17V. The device shows a maximum external efficiency of 1.4%. The CIE coordinates are well within the white-light region when the applied voltage varies between 5.0 to 17V.
Micro-dynamics of Ca2+ signals in single heart cells
Authors: Bai Yong-Qiang  , Tang Ai-Hui  , Wang Shi-Qiang  , Zhu Xing  ,   (1)北京大学生命科学学院，生物膜与膜生物工程国家重点实验室，北京 100871; (2)北京大学物理学院，人工微结构与介观物理国家重点实验室，北京 100871;大庆石油学院电子科学学院，大庆 163318; (3)北京大学物理学院，人工微结构与介观物理国家重点实验室，北京 100871;国家纳米科学中心，北京 100080
Published: December 2020

We used a total internal reflection fluorescence microscope based on the near field optics principle to study the Ca2+ signals in single heart cells of Sprague-Dawley rat. Due to the high signal to noise ratio and high speed of data acquisition of this microscope, the Ca2+ images show complex 2-dimensional wave patterns. The local elementary Ca2+ release units play important role in the formation and transformation of Ca2+ wave. Simulations based on Fire-Diffuse-Fire model show that the Ca2+ wave, composed of Ca2+ release units, may steadily exist in single heart cell. Our results will be helpful for understanding the micro-dynamics of living excitable medium.
Matrix elements and classical limit of relativistic particles in infinitely deep potential well
Authors: Liang Mai-Lin  , Zhang Fu-Lin  , Yuan Bing  ,   天津大学理学院物理系,天津 300072
Published: December 2020

For relativistic particles with spin-0 (satisfying the Klein-Gordon equation) and spin-1/2 (satisfying the Dirac equation) in infinitely deep potential well, matrix elements for the coordinate, momentum and the velocity operators are calculated. In the limit of large quantum numbers, these matrix elements give the corresponding classical quantities (nowbeing related quantities in special relativity) and satisfy exact classical relations. These results show that the Heisenberg correspondence principle is applicable to such relativistic systems.
Dynamical behavior of a completely inelastic ball bouncing on a vibrating plate
Authors: Jiang Ze-Hui  , Zheng Rui-Hua  , Zhao Hai-Fa  , Wu Jing  ,   哈尔滨工业大学物理系，哈尔滨 150001
Published: December 2020

A simple analysis for the behavior of a completely inelastic ball bouncing on a vertically vibrating plate has been given. Controlled by the normalized vibration acceleration, the ball undertakes a serials of subharmonic bifurcations. Several typical bifurcation processes are discussed.
Generation of chirped pulses at high repetition rate with a Ti：sapphire regenerative amplifier
Authors: Feng Wei-Wei  , Lin Li-Huang  , Wang Wen-Yao  , Li Ru-Xin  , Wang Li-Chun  ,   (1)中国科学院上海光学精密机械研究所强场激光物理国家重点实验室，上海 201800; (2)中国科学院上海光学精密机械研究所强场激光物理国家重点实验室，上海 201800;中国科学院研究生院，北京 100049
Published: December 2020

We present a method to obtain a laser pulse train at high repetition rate for the Ti：sapphire laser system based on the chirped pulse amplification technique. The conventional working mode of the Pockels cell in the Ti：regenerative amplifier is modified. At a certain dumping time, a portion of the amplified seed pulse is dumped out of the cavity by a certain dumping ration every time the pulse runs around the cavity. Thenceforward, the chirped pulses at high repetition rate are generated. Based on the Franz-Nodvik amplification theory，a theoretical model of the regenerative amplifier is established and the analysis of the dependence of the pulse sequence on the dumping time and dumping ratio is given by numerical computation. With a pumping energy of 35mJ and a dumping ratio of 1/2, a fourteen-pulse sequence at 100MHz with pulse energy of 0.02mJ is obtained at a finite period of time in a pumping cycle.
Effect of La2O3 doping on the spectroscopic properties of transparent Yb:Y2O3 laser ceramics
Authors: Yang Qiu-Hong  , Xu Jun  , Dou Chuan-Guo  , Zhang Hong-Wei  , Ding Jun  , Tang Zai-Feng  ,   (1)上海大学材料科学与工程学院，上海 200072; (2)中国科学院上海光学精密机械研究所，上海 201800
Published: December 2020

The effect of La2O3 doping on the spectroscopic properties of transparent Yb：Y2O3 ceramics was studied. After doping La2O3，the shapes and positions of the absorption and emission peaks of transparent (Yb0.05Y0.95-xLax)2O3 ceramics were almost the same as those of Yb：Y2O3. When La2O3 was added into Yb：Y2O3，the lattice constant of (Yb0.05Y0.95-xLax)2O3 became large and the crystal field strength weaker due to introducing of larger radius of La3+ ion, simultaneously its degree of order is decreased, which results in the decrease of the emission intensities and the emission cross-sections. The emission intensities were reduced greatly for the excessive doping of La2O3 (16at%) in (Yb0.05Y0.95-xLax)2O3 ceramics. On the whole the fluorescent lifetimes of the samples are increased by 45%—60% after doping La2O3.
Intermolecular potential energy and band calculation in polymorphs of pentacene
Authors: Guo Shu-Xu  , Wang Wei  , Shi Jia-Wei  ,   吉林大学电子科学与工程学院，集成光电子学国家重点联合实验室, 长春 130012
Published: December 2020

Pentacene crystallizes in a layered structure with a herringbone arrangement within the layers. There exist several polymorphs of pentacene. Identification of these pentacene polymorphs is especially important as the electronic properties depend strongly on the stacking of the molecules within the layers. In this paper the intermolecular potential energy of the pentacene crystal is represented by Born-Mayer-Haggins pair potential model. We have performed electronic band structure calculation based on the tight-binding model for the two polymorphic crystal structures of pentacene. The calculated bandwidth reduction in going from 0K to room temperature is of the order of 8%—14%.
Weak anti-localization in InAlAs/InGaAs/InAlAs high mobility two-dimensional electron gas systems
Authors: Zhou Wen-Zheng  , Lin Tie  , Shang Li-Yan  , Huang Zhi-Ming  , Cui Li-Jie  , Li Dong-Lin  , Gao Hong-Ling  , Zeng Yi-Ping  , Guo Shao-Ling  , Gui Yong-Sheng  , Chu Jun-Hao  ,   (1)中国科学院半导体研究所，北京 100083; (2)中国科学院上海技术物理研究所红外物理国家重点实验室，上海 200083; (3)中国科学院上海技术物理研究所红外物理国家重点实验室，上海 200083;广西大学物理科学与工程技术学院，南宁 530004; (4)中国科学院上海技术物理研究所红外物理国家重点实验室，上海 200083;华东师范大学ECNU-SITP成像信息联合实验室，上海 200062
Published: December 2020

Magneto-transport measurements have been carried out on three heavily Si δ-doped In0.52Al0.48As/In0.53Ga0.47As/In0.52Al0.48As single quantum well samples in which two subbands were occupied by electrons. The weak anti-localization (WAL) has been found in such high electron mobility systems. The strong Rashba spin-orbit (SO) coupling is due to the high structure inversion asymmetry (SIA) of the quantum wells. Since the WAL theory model is so complicated in fitting our experimental results, we obtained the Rashba SO coupling constant　α and the zero-field spin splitting　Δ0 by an approximate approach. The results are consistent with that obtained by the Shubnikov-de Haas (SdH) oscillation analysis. The WAL effect in high electron mobility system suggests that finding a useful approach for deducing α and Δ0 is important in designing future spintronics devices that utilize the Rashba SO coupling.
Electronic trap effect of spectral sensitizing dye adsorbed on the surface of silver chloride
Authors: Li Xiao-Wei  , Zhang Ji-Xian  , Zhang Rong-Xiang  , Lai Wei-Dong  , Li Li  , Dai Xiu-Hong  , Fu Guang-Sheng  ,   河北大学物理科学与技术学院，保定 071002
Published: December 2020

Using spectral sensitizing technology，silver halide microcrystals can be sensitized to the visible light region. The spectral sensitizing technology is important to the modern information recording and storage，solar energy transfer and storage, and the photoelectronic devices. The photoelectron decay characteristic of silver chloride microcrystals，which is adsorbed with green sensitizing cyanine dye，is studied by microwave absorption and dielectric spectrum detection technology. The model of photoelectron decay is set up. Electron trap effect of the dye in the silver halide surface is analyzed based on the photoelectron decay model and the photoelectron decay characteristic. The results show that when the mono-molecular dye is adsorbed on the surface，shallow electron traps are created; when the J-aggregated dye is adsorbed on the surface，deep electron traps are created. The critical dose of dye that seperates the shallow electron trap and deep electron trap effects is 0.2ml of dye (with concentration of 5.0mg/ml) per 40g AgCl emulsion.
Mesoscopic mechanical characterization of hydrogenated silicon thin film and the intrinsic relationship with the microstructure
Authors: Wang Quan  , Ding Jian-Ning  , He Yu-Liang  , Xue Wei  , Fan Zhen  ,   (1)江苏大学微纳米科学技术研究中心，镇江 212013; (2)江苏大学微纳米科学技术研究中心，镇江 212013;南京大学物理系，南京 210093; (3)温州大学工业工程学院，温州 323035
Published: December 2020

Hydrogenated silicon films were deposited on glass and single crystalline silicon substrate in a capacitively coupled radio-frequent plasma enhanced vapor deposition system aided by direct current bias excitation. Hydrogenated silicon films are used to realize a silicon material that consists of a two-phase mixture of amorphous and ordered silicon. Micro-Raman scattering is employed to investigate the thin film microstructure. The crystalline volume fraction (Xc) is obtained from the Raman spectra. Mesoscopic mechanical characterization of the thin film is done by nanoindentation based on the conventional depth-sensing indentation method. An analytical relation between Xc and elastic modulus is established. It is shown that the elastic modulus of the film on glass substrate is lower than that on silicon with the the same Xc. The grain size of phosphorus doped thin film is smaller than that of the intrinsic one and more ordered. The Xc is usually above 40%. The film with diborane doping is on the opposite, the Xc of which is usually below 40%. For P-doped, intrinsic and B-doped fims, when the Xc values are 45%, 30% and 15%, respectively, the values of elastic modulus are minimal.
Study on bubble nucleation in liquid metal
Authors: Zhang Hua-Wei  , Li Yan-Xiang  ,   清华大学机械工程系，先进成形制造教育部重点实验室，北京 100084
Published: December 2020

The nucleation mechanism of gas bubbles in melts was studied theoretically by three representative models, uamely the homogeneous nucleation in liquid metal, heterogeneous nucleation on the flat surface or in conic pits of refractory inclusions, under the assumption that the state of the system's Gibbs free energy change being maximal is the critical state of bubble nucleation. Introducing the contact angle and considering the effect of interfacial tension on bubble morphology, the following conclusions can be drawn: the critical nucleation radius of bubbles in the three models is the same, which will be reduced with increasing gas pressure above the liquid metal. The diameter of embryo bubbles, which is also the minimum pore size in lotus-type porous metal ingots, has a magnitude of micrometers under the common pressure of 0.1—1.0 MPa for the Gasar process. For heterogeneous bubble nucleation in conic pits of inclusions, there exists an optimal cone apex angle corresponding to the smallest volume of the embryo bubble, which is independent of gas pressure above liquid metals and increases with the increase of the contact angle. For alumina inclusion in Mg, Al, Fe, Ni and Cu melts, the optimal apex angles are 8.0°, 19.5°, 20.6°, 42.7° and 51.5°, respectively. Among these three bubble nucleation models, homogeneous nucleation is the most difficult, heterogeneous nucleation in conic pits of inclusions is the easiest, and heterogeneous nucleation on the flat surface of inclusions is intermediate.
Effect of the relative orientation of molecules on the electronic transport property of molecular devices
Authors: Xia Cai-Juan  , Fang Chang-Feng  , Hu Gui-Chao  , Li Dong-Mei  , Liu De-Sheng  , Xie Shi-Jie  ,   (1)山东大学物理与微电子学院，晶体材料国家重点实验室，济南 250100; (2)山东大学物理与微电子学院，晶体材料国家重点实验室，济南 250100;济宁学院物理系，曲阜 273100
Published: December 2020

Based on ab initio methods and nonequilibrium Green's function theory, we have investigated the electronic transport properties of single and double 1，4-dithiolbenzene molecular devices which have different molecular relative orientations on molecule-metal contacts. Numerical results show that different molecular relative orientations have various influences on the electronic structure of molecules and current-voltage characteristics, which obviously affects the electronic transport properties of metal-molecule-metal systems. The equilibrium state of the extend molecule is not the best situation for electronic transportation. The characteristics of electronic transportation can thus be improved by adjusting the molecular relative orientation on molecule-metal contacts.
Laboratory simulation of femtosecond laser guided lightning discharge
Authors: Zhang Zhe  , Lu Xin  , Hao Zuo-Qiang  , Zhang Shi-Chang  , Zhang Dong-Dong  , Wang Zhao-Hua  , Ma Yuan-Yuan  , Yan Ping  , Zhang Jie  ,   (1)中国科学院电工研究所，北京 100080; (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 100080
Published: December 2020

We triggered and guided the stationary electric field discharges in 3—23 cm long air gaps by using plasma channels produced by 40mJ ultrashort laser pulses. We have observed that the plasma channel reduced the discharge breakdown voltage to 40% of its natural value. By analyzing the delay between the laser pulse and the white light emission of discharge, we evaluated the speed of the stepped leader with laser guiding to be about 107 cm/s.
Study of the heat effect of single steady-state microdischarge during plasma electrolytic oxidation
Authors: Wang Li-Shi  , Pan Chun-Xu  , Cai Qi-Zhou  , Wei Bo-Kang  ,   (1)华中科技大学材料科学与工程学院，武汉 430074; (2)武汉大学物理科学与技术学院，武汉 430072
Published: December 2020

This paper systematically reviews the researches on the heat effect of a single steady-state microdischarge during plasma electrolytic oxidation (PEO) and explaines the causes for the appareut changes of microdischarge population which may be related with the evolution of the type and quantity of the disintegrated gas bubbles formed in the interface between the electrolyte and the substrate. The temperature field inside a microdischarge was estimated by virtue of a cylindrical channel model of microdischarge, and the temperature effect in the coatings adjacent to the microdischarge channel was calculated through the heat transfer equation of point heat source during the decay process of microdischarge, which provides a preliminary theoretical analysis for the types and crystalline states of different phase compositions (MgAl2O4,Mg2SiO4, etc.) contained in the coating formed on the magnesium alloy.
Magetostriction, spin reorientation and M?ssbauer effect studies of Tb0.3Dy0.7－xPrx(Fe0.9Al0.1)1.95 alloys
Authors: Zheng Xiao-Ping  , Zhang Pei-Feng  , Fan Duo-Wang  , Li Fa-Shen  , Hao  Yuan  ,   (1)兰州城市学院电子信息科学与技术研究所，兰州   730070;兰州交通大学光电技术与智能控制教育部重点实验室，兰州   730070;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)兰州大学磁学与磁性材料教育部重点实验室，兰州   730000; (3)兰州交通大学光电技术与智能控制教育部重点实验室，兰州   730070; (4)兰州交通大学光电技术与智能控制教育部重点实验室，兰州   730070;兰州大学磁学与磁性材料教育部重点实验室，兰州   730000; (5)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

The effect of Pr substitution for Dy on the structure, magnetostriction, anisotropy and spin reorientation of a series of Tb0.3Dy0.7-xPrx(Fe0.9Al0.1)1.95 alloys (x=0, 0.1, 0.20, 0.25, 0.30, 0.35) at room temperature has been investigated. It was found that the Tb0.3Dy0.7-xPrx(Fe0.9Al0.1)1.95 substantially retained the MgCu2-type C-15 cubic Laves phase structure for compositions with x≤0.1 and the lattice constant increases slowly with increasing x. The magnetostriction of the Tb0.3Dy0.7-xPrx(Fe0.9Al0.1)1.95 alloys decreases drastically with increasing x and the magnetostrictive effect disappears for x>0.2. However, the magnetostriction shows a slightly bigger value at x=0.1 than the free alloys and is saturated more easily with the magnetic field H, showing that a small amount of Pr substitution is beneficial to the decrease in the magnetocrystalline anisotropy. The spontaneous magnetostriction λ111 increases linearly with incresasing x， whereas the spin reorientation temperature increases first and then decreases rapidly. The analysis of the Mssbauer spectra indicated that the easy magnetization direction in the {110} plane deviates slightly from the main axis of symmetry with the increase in Pr concentration x， namely the spin reorientation. Compared with the Al substitution，the effect of Pr substitution for Dy on the spin reorientation is smaller.
Fabrication of a new organic multilayer phosphorescent white-light-emitting device and evaluation of its characteristics
Authors: Zhang Guo-Hui  , Hua Yu-Lin  , Wu Xiao-Ming  , Yin Shou-Gen  , Niu Xia  , Hui Juan-Li  , Wang Yu  , Zhang Li-Juan  ,   天津理工大学材料物理研究所,天津市光电显示材料与器件重点实验室,天津 300384
Published: December 2020

A novel organic phosphorescent white-light-emitting device (WOLED) with configuration of ITO/NPB/NPB:Ir(piq)2(acac)/CBP:TBPe /BAlq:rubrene/BAlq/Alq3/Mg:Ag is fabricated successfully, in which the phosphorescent dye (Ir(piq)2(acac)) doped into NPB (hole transport material), fluorescent dye (TBPe) doped into CBP (ambipolar conductivity material) and another fluorescent dye (rubrene) doped into BALq (electron transport material) work as the red, blue and green emitting layer, respectively. The emitting layers are sandwiched between the undoped NPB and BALq layers. The charge distribution has been balanced for the introduction of heterojunctions between the different emitting layers, which results in a high fabrication reproducibility of the device. White emission is obtained by tuning the thickness and doping proportions of each layer. The device turns on at the driving voltage of 4.5 V. It shows a maximum external quantum efficiency and brightness of 1.5 % and 16260 cd/m2, respectively. The Commission Internationale de l'Eclairage (CIE) coordinates varies from (0.396, 0.432) at 5 V to (0.411, 0.414) at 20 V. The emission spectra of the device mainly consist of blue (464 nm), green (552 nm) and red (620 nm) emissions peaks, which are particular suitable to be combined with color filters to obtain the three primary colors and further achieve full color displays.
The electrical trees that developed in inner and outer layer of XLPE cable insulation
Authors: Zheng Xiao-Quan  , Xie An-Sheng  , Li Sheng-Tao  ,   (1)西安交通大学电力设备电气绝缘国家重点实验室，西安 710049; (2)西安交通大学电力设备电气绝缘国家重点实验室，西安 710049;长安大学环境科学与工程学院，西安 710064
Published: December 2020

Due to the limitations of specific insulation structures and the influence of technical process，the growth of electrical trees in high-voltage power equipments with polymer as main insulation materials is more complicated than those in uniform materials，especially in equipment employing semi-crystalline polymer，so it is difficult to characterize by mathematical means. The experiment reported in this paper is the first attempt to focus on the electrical treeing rules in both inner and outer insulation layers of high-voltage XLPE power cable. Through statistical experiments and the SEM observation，large difference in treeing character between the inner and outer layers of cable insulation due to the different crystalline status are found. Electrical trees initiating in the inner layer of insulation has shorter initiation time，higher growth rate and greater variety of shapes compared than in the outer layers. The initiation and propagation mechanisms are also discussed.
New variable separation solutions, localized structures and fractals in the (3+1)-dimensional nonlinear Burgers system
Authors: Huang Lei  , Sun Jian-An  , Dou Fu-Quan  , Duan Wen-Shan  , Liu Xing-Xia  ,   西北师范大学物理与电子工程学院，兰州  730070
Published: December 2020

Applying the extended Riccati mapping approach to the (3+1)-dimensional nonlinear Burgers system, we obtain new variable separation solutions which contain an arbitrary function. With the help of numerical simulation of Mathematica, abundant special types of new localized excitations and fractals are discussed by selecting the arbitrary function appropriately. The solutions indicate that the extended Riccati mapping approach is valid for solving a class of (3+1)-dimensional nonlinear equations and can obtain much more abundant localized excitations than that of the (2+1)-dimensional nonlinear equations.
Global exponential stabilization for parabolic type systems with continuously distributed delays
Authors: Luo Yi-Ping  , Deng Fei-Qi  , Li An-Ping  ,   (1)湖南工程学院，湘潭  411101; (2)湖南工程学院，湘潭  411101；华南理工大学系统工程研究所，广州  510640; (3)华南理工大学系统工程研究所，广州  510640
Published: December 2020

A sort of new method is put forward which is not similar to existing methods for a class of parabolic type systems with time-varying delays. By employing generalized Halanay's inequality, Dini derivative and the technique of differential inequality, a sufficient condition for the type of stabilization are derived. The stabilization criteria are delay-independent. A computation example is given to illustrate the proposed method. In addition, the distinct advantage of the method is that the criterions in the paper are easy to be checked, and can be applied in practice easily.
Investigation of the SiC nano-bar relaxation characteristics
Authors: Tian Jian-Hui  , Han Xu  , Liu Gui-Rong  , Long Shu-Yao  , Qin Jin-Qi  ,   (1)湖南大学力学与航空航天学院，长沙  410082; (2)湖南大学汽车车身先进设计制造国家重点实验室，长沙  410082
Published: December 2020

The SiC nano-bar relaxation has been investigated using MD method. The Tersoff potential is adopted as the potential function. The characteristic of the homeostasis of SiC nano-bar relaxation is demonstrated. The nano-bar is affected by the strong surface effect and small size effect. The phenomena of torsion and bending is observed during the relaxation.
Prediction of chaotic time series based on fractal self-affinity
Authors: He Tao  , Zhou Zheng-Ou  ,   电子科技大学电子工程学院，成都  610054
Published: December 2020

Based on the fractal structure of strange attractor and self-affine property of time series, a method is proposed for predicting chaotic time series. The algorithm first exploits the iterative function system to track current chaotic trajectory and selects the segment which possesses the best self-affine property of the time series statistically. Then the prediction model is constructed according to attractor and coverage theorem. To illustrate the performance of the proposed model, simulations are performed on the chaotic Mackey-Glass time series, EEG signal and Lorenz chaotic system. The results show that the chaotic time series are accurately predicted, which demonstrates the effectiveness of the model.
Analytical solution for temperature oscillation in the heater/thermometer film in 3ω method and its application to thermal conductivity measurement of micro/nanometer-films
Authors: Wang Zhao-Liang  , Tang Da-Wei  , Jia Tao  , Mao An-Min  ,   (1)中国科学院工程热物理研究所，北京  100080; (2)中国科学院工程热物理研究所，北京  100080；中国科学院研究生院，北京  100039; (3)中国科学院数学与系统科学研究院，北京  100080
Published: December 2020

Analytical solution in terms of series for temperature oscillation in the heater/thermometer film is derived for 3ω measurements. The complex temperature solution is seperated into the real and imaginary parts. Analysis is performed to show the effect of the combined parameters of ac frequency, heater width and sample thermal properties on the temperature oscillation. The mathematical model for the measurement is corrected based on the solution. Accordingly, a 3ω setup is developed to determine thermal conductivity of 500 nm-thick thin film on Si substrate. Uncertainty analysis and comparison with the results of differential-3ω methods and published values are made, the results show good mutual agreement. The thermal conductivities of SiO2 film and Si substrate are determined simultaneously with the series solution and by extension to high frequency. The method is also employed to measure the thermal conductivity of the multi-layer antireflective coating of ZrO2/SiO2 deposited on Nd:YAG surface. The ZrO2 film has a thermal conductivity smaller than the volume value. The established 3ω setup and analytical method can be applied to investigate the thermal performance of thin film-substrate structures for use with micro-systems such MEMS.
The quantum statistical properties of a class of superposed q-deformed generalized coherent states
Authors: Ren Min  , Ma Ai-Qun  , Muhammad Ashfaq Ahmad  , Zeng Ran  , Liu Shu-Tian  , Ma Zhi-Min  ,   (1)广州大学工程抗振中心，广州  510405; (2)哈尔滨工业大学应用物理系，哈尔滨  150001; (3)哈尔滨师范大学呼兰学院物理系，哈尔滨  150050; (4)黑龙江大学物理科学与技术学院，哈尔滨  150080；广州大学城建学院，广州  510905；哈尔滨工业大学应用物理系，哈尔滨  150001
Published: December 2020

In this paper, the quantum statistical properties of a class of superposed q-deformed generalized coherent states |ψ>=a|β>+beiφ|βeiδ> are studied. The results show that the superposition of q-deformed coherent generalized states generally exhibits squeezing and anti-bunching effects. The change of the phase difference between two generalized coherent states, the phase difference between two superposition coefficients, and both the amplitude and phase of the inner product of two generalized coherent states play important roles in squeezing effect and anti-bunching effect.
Ultrashort pulsed complex argument Sinc-Gaussian beams
Authors: Yang Zhen-Feng  , Yang Zhen-Jun  , Hu Wei  ,   (1)河北科技大学经济管理学院，石家庄  050018; (2)河北师范大学物理学院，石家庄  050016; (3)华南师范大学传输光学实验室，广州  510631
Published: December 2020

By using slowly-varying envelope approximation, a family of solutions of the paraxial wave equation are found in theory, which represents a new family of ultrashort pulsed beams called ultrashort pulsed complex argument Sinc-Gaussian beams. These pulsed beams with a certain frequency have a nearly complex argument Gaussian profile, a sinc function temporal shape. The ultrashort pulsed complex argument Sinc-Gaussian beams and their propagation properties in free space are studied detailedly, such as intensity on the axis, transversal intensity distribution of the pulsed beams, polarity reversal, pulse time delay, etc..
Study on stimulated Brillouin scattering pulse waveform
Authors: Hasi Wu-Li-Ji  , Lü Zhi-Wei  , Teng Yun-Peng  , Liu Shu-Jie  , Li Qiang  , He Wei-Ming  ,   哈尔滨工业大学光电子技术研究所，哈尔滨  150001
Published: December 2020

In this paper, the pulse waveform of stimulated Brillouin scattering (SBS) is investigated experimentally and theoretically. The variations of SBS pulse waveform with pump parameters, structural parameters and medium parameters are experimentally investigated with a Nd∶YAG Q-switched laser，and numerically simulated using SBS theory model. The theoretical calculations are in good agreement with the experimental results. The results indicate that modulation of pulse waveform is difficult to realige with low pump energy, short focal length, long lens-cell distance and long phonon life time. The influence of the pump parameters, structural parameters and medium parameters on SBS pulse waveform is discussed extensively.
The influence of absorption and fluorescence from the solution on the stimulated Raman threshold of CS2 in liquid-core optical fiber
Authors: Zuo Jian  , Li Zuo-Wei  , Tian Yan-Jie  , Chen Jian  , Gao Shu-Qin  , Lu Guo-Hui  ,   吉林大学物理学院光学系，长春  130021
Published: December 2020

It is shown from experiments that the stimulated Raman thresholds of the first and the second Stokes lines of CS2 are influenced by the absorption and fluorescence from the solution of β-Carotene in CS2 in liquid core optical fiber. The threshold of the first Stokes line of CS2 becomes higher when the concentration of the solution increases. And the second Stokes line of CS2 can be observed at a lower pump energy in the solution of β-Carotene in CS2 compared with that of the solution of pure CS2. Then the theoretic explanations are given and the theoretic results agree well with the experimental results.
Inductively coupled plasma etching of two-dimensional InP/InGaAsP-based photonic crystal
Authors: Ma Xiao-Tao  , Zheng Wan-Hua  , Ren Gang  , Fan Zhong-Chao  , Chen Liang-Hui  ,   (1)半导体集成技术工程研究中心，中国科学院半导体研究所,北京  100083; (2)纳米光电子实验室，中国科学院半导体研究所,北京  100083
Published: December 2020

Inductively coupled plasma (ICP) etching of InP in Cl2/BCl3 gas mixtures is studied in order to achieve low-damage and high-anisotropy etching of two-dimensional InP/InGaAsP photonic crystal. The etching mechanisms are discussed and the effect of plasma heating on wafer during etching is analyzed. It is shown that the balance between the undercut originating from plasma heating and the redeposition of sputtering on the side-wall is crucial for highly anisotropic etching, and the balance point moves toward lower bias when the ICP power is increased. High aspect-ratio etching at the DC bias of 203 V is obtained. Eventually, photonic crystal structure with nearly 90° side-wall is achieved at low DC bias after optimization of the gas mixture.
Study of transport of hot electrons in solid targets using transition radiation
Authors: Wang Guang-Chang  , Zheng Zhi-Jian  , Gu Yu-Qiu  , Chen Tao  , Zhang Ting  ,   (1)成都医学院物理教研室,成都  610083; (2)成都医学院物理教研室,成都  610083；中国工程物理研究院 激光聚变研究中心,绵阳  621900; (3)中国工程物理研究院 激光聚变研究中心,绵阳  621900
Published: December 2020

For studing the transport of hot electrons in solid targets by transition radiation, the image pattern of spatial distribution and spectrum of optical emission were measured at the normal direction from the rear side of targets employing optical CCD camera and OMA optical multi-channel spectrometer on the 100 TW femtosecond laser facility.The image pattern of spatial distribution has a disc-shape, in which is distributed a bright localized signal, which shows the filament effect during hot electron transport. The spectrum of optical emission has sharp peaks near the 3 and 3/2 multiple of the fundamental frequency, corresponding to the third-order harmonic and 3/2-order harmonics, respectively, which is ascribed to the coherent transition radiation (CTR) generated by microbunches of hot electron beams produced in transport. The intensity of transition radiation decreases with the increase of target thickness.
Investigation on Kα Ｘ-ray emission from ultraintense laser-produced hot electrons
Authors: Huang Wen-Zhong  , Li Yu-Tong  , Xiong Yong  , Zhang Shuang-Gen  , Wen Xian-Lun  , Hong Wei  , Gu Yu-Qiu  , Wen Tian-Shu  , He Ying-Ling  ,   (1)中国工程物理研究院激光聚变研究中心，绵阳  621900; (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  100080
Published: December 2020

A dispersionless X-ray Kα spectrometer is constructed. The experiments were performed using the SILEX-I laser facility. The Kα Ｘ-ray emission from ultraintense laser-plasma interactions is measured with the spectrometer in front of and behind the foil targets. The conversion efficiency from laser energy to Kα Ｘ-ray is obtained. The experimental results show that the Kα yield increases with the laser energy. With a 100μm thick Mo foil, the conversion efficiency is 10-5.
Influence of user requirement behaviors on internet collective dynamics
Authors: Ma Wei-Dong  , Wang Lei  , Li You-Ping  , Shui Hong-Shou  , Zhou Ming-Tian  ,   (1)电子科技大学计算机学院,成都  610054; (2)电子科技大学计算机学院,成都  610054；中国工程物理研究院,绵阳  621900; (3)清华大学电子工程系，北京  100084; (4)中国工程物理研究院,绵阳  621900
Published: December 2020

The complex network dynamics of the Internet is mainly influenced by user requirement behaviors, and can be statistic in time series. A large number of complex networks, both natural and artificial, share the presence of highly heterogeneous, scale-free degree distributions and small-world phenomena. This paper analyzed the empirical collective behavior of user requirements in a region, and discovered that the frequency and the in-degree distributions of bipartite networks constructed by user visiting web sites follows the power-law, and the exponent is between 1.7 and 1.8. A novel two-tier model, the virtual resource networks (VRN) and physics topology networks (PTN), is proposed to study the influences on the Internet collective behaviors. The mapping process mechanisens of VRN to PTN simulates how the dynamic behaviors of resource network influence the internet physics topology networks. The power-law characteristics of VRN can bring forth the result that the phase transition critical point moves left and network performance is more incapable. The distributed mapping process of VRN to PTN was constructed for the small subset with the high degree nodes, then the phase transition critical point of PTN moves right and the network performance is improved obviously.
Investigation on an S-band relativistic klystron oscillator
Authors: Huang Hua  , Gan Yan-Qing  , Lei Lu-Rong  , Jin Xiao  , Ju Bing-Quan  , Xiang Fei  , Feng Di-Chao  , Liu Zhong  ,   中国工程物理研究院应用电子学研究所，绵阳  621900
Published: December 2020

The physics of modulation and rf extraction of an S-band relativistic klystron oscillator is studied in this paper via experiment, theory, and simulation. It is found that the intense relativistic electron beams (IREBs) can be intensely current-modulated when the IREBs drift through three pillboxes with high coupling. After bunching in the downstream the modulated IREBs can excite high-power microwave in the triaxial cavity. These properties, which have short oscillating time, compact geometry and high beam-wave conversion efficiency, were encouraging. Using a 1 MV, 13 kA, 40 ns electron beam and a 0.9 kGs leading magnetic field, 3.5 GW radiated power was extracted in 20 ns FWHM pulses at 2.86 GHz. The efficiency was 27%, and the instantaneous bandwidth was 2%. The radiated power was 3.4 GW when the repetition rate IREBs was 20 Hz. The experimental results agree well with the simulations.
The theoretical model of broad band dye laser and experimental validation
Authors: Wang Mo-Ge  , Lu Qi-Sheng  , Xu Xiao-Jun  , Guo Shao-Feng  ,   国防科学技术大学光电科学与工程学院，长沙  410073
Published: December 2020

The spectral competition in pulsed dye laser is modified by semiclassical dye laser theory，showing good agreement with experimental results.Under the circumstance of interrelated competition of double-wave，the tuned spectrum is expanded by 25%.The spectrum is gradually compressed with the increasc of the coupler loss under the condition of broad spectrum width.
A novel method for fabricating sampled fiber grating amplitude mask
Authors: Liu Yan  , Li Bin  , Lu Shao-Hua  , Xu Ou  , Ren Wen-Hua  , Wang Yan-Hua  , Feng Su-Chun  , Jian Shui-Sheng  ,   全光网络与现代通信网教育部重点实验室，北京交通大学，北京  100044;北京交通大学光波技术研究所,北京  100044
Published: December 2020

A novel method for fabricating sampled amplitude mask is presented, the featureof which is the varying sampling period and fixed sampling duty ratio. By usingsuch an amplitude mask, sampled fiber gratings with different wavelength spacings of reflectivity peaks can be easily fabricated. So the novel method has the advantages of reduced fabrication cost and improved versatility of sampled grating. The possible disadvantages of the method are also discussed. Wavelength selectable fiber laser with vernier wavelength tuning mechanism is also demonstrated by the sampled fiber grating.
Comparison of magnetic properties of Fe/Co multilayers prepared by DC magnetron sputtering on glass and Si substrates
Authors: Xia Ai-Lin  , Han Bao-Shan  ,   (1)安徽工业大学材料科学与工程学院，马鞍山  243002; (2)中国科学院物理研究所磁学国家重点实验室，北京  100080
Published: December 2020

We presented a comparison of magnetic properties of ［Cot/Fe3t］5 (t=2, 3, 4, 5nm) multilayers prepared by DC magnetron sputtering on glass and Si substrates. For the multilayers with the same t but prepared on different substrates, it was found that the saturated magnetization differed little, but the coercivity differed greatly. Moreover, the difference in coercivity mechanism was analyzed theoretically to explain this difference.
Resistivity of PZT 95/5 ferroelectric ceramic under shock wave compression
Authors: Jiang Dong-Dong  , Du Jin-Mei  , Gu Yan  , Feng Yu-Jun  ,   (1)西安交通大学电子材料与器件研究所，西安  710049; (2)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实验室，绵阳  621900; (3)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实验室，绵阳  621900；西安交通大学电子材料与器件研究所，西安  710049
Published: December 2020

Resistivity of the shocked PbZr0.95Ti0.05O3(PZT 95/5) ferroelectric ceramic has been determined under shock wave compression. A physical model has been developed which takes into account the finite resistivity of ferroelectric ceramic compressed by shock wave propagating in a direction perpendicular to the remanent polarization vector. The results reveal that under the pressure of about 2.0 GPa under short circuit, the resistivity of the shocked PZT 95/5 ceramic drops very quickly from 107—1011Ωcm to a minimum of 40Ωcm and then rises to values between 120 and 140Ωcm until the end of the shock depoling.
Phase transition and entanglement entropy of Bose-Einstein condensates in double-well trap under periodic modulation
Authors: Fang Yong-Cui  , Yang Zhi-An  , Yang Li-Yun  ,   (1)北京应用物理与计算数学研究所，北京  100088; (2)济南大学理学院，济南  250022
Published: December 2020

Dynamical phase transition of Bose-Einstein condensates (BEC) in double-well trap with external periodic modulation applied to the interaction term is investigated in this paper. Particularly, phase transition to chaos is studied. It is found that, when resonance between the modulation frequency and the natural frequency of the system happens, the system turns to instability (chaos) at certain values of the parameters. In the chaotic region, distribution of particles is random, and the average of population difference fluctuates around zero. Especially, chaos can be manifested by the entanglement entropy. In the chaotic zone, both of the average entanglement entropies approach to their maxima.
A modified digraph cell mapping method
Authors: He Qun  , Xu Wei  , Li Shuang  , Xiao Yu-Zhu  ,   西北工业大学理学院应用数学系，西安  710072
Published: December 2020

By introducing new concepts, this paper presents a new classification of transient cells for the digraph cell mapping dynamical system. Based on this new classification, the approximation problem of the invariant manifolds of dynamical system is discussed in detail. In order to improve the efficiency and speed of computing, an effective algorithm is given to complete the above classification. As an illustrative example, Henon map is taken to demonstrate the validity of the modified digraph cell mapping method.
Temperature measurement with one dimensional defect photonic crystal
Authors: Tong Kai  , Cui Wei-Wei  , Wang Mei-Ting  , Li Zhi-Quan  ,   (1)燕山大学电气工程学院，秦皇岛  066004; (2)燕山大学继续教育学院，秦皇岛  066004
Published: December 2020

Si and SiO2 were used as materials to build the one-dimension (1D) defect photonic crystal and the medium of detect layer is Si. Using transfer matrix method, the optical transmission properties in 1D defect photonic crystals was analyzed, and the band gap property of 1D photonic crystal was obtained. Because of the defect, the defect peak appears in the transmission spectra. According to thermo-optical effect and thermal-expansion effect the optical depth and index of the materials and the defect of photonic crystal vary when the temperature changes. So the temperature can be measured by the wavelength shift value of the defect peak. Using 1D defect photonic crystal an experimentation system was set up for temperature measurement. The result showed that there is a linear relationship between the temperature of photonic crystal and the wave-length of the peak. And the sensitivity of this measuring system is 0207nm/℃ and the measurement range is -20—120℃.
Development of a system of measuring 37Ar by spectrum method
Authors: Xiang Yong-Chun  , Gong Jian  , Li Wei  , Bian Zhi-Shang  , Hao Fan-Hua  , Wang Hong-Xia  , Wang Qian  , Xiong Zong-Hua  ,   中国工程物理研究院 核物理与化学研究所，绵阳  621900
Published: December 2020

A portable system of measuring 37Ar has been developed. Measurement of 37Ar is realized by the proportional counter and spectrum analysis method. Plateau length, plateau slope and background have been analyzed. Compared with traditional counting method, the present method has the advantages of visibility, longer plateau length and smaller plateau slope. background is reduced by an order of magnitude which decreases the detection limit. Working gas of 10% methane improves the peak shape. Greater concentration of methane is not necessary because it does not make the peak shape better but needs higher working voltage.
The research on half-analytical method in calculating the magnetic field of unbalanced magnetron sputtering
Authors: Han Liang  , Zhao Yu-Qing  , Zhang Hai-Bo  ,   西安交通大学电子物理与器件教育部重点实验室，西安  710049
Published: December 2020

Half-analytical method is a new method of calculating electromagnetic field. In this paper, this method is applied to analyzing magnetic field in unbalanced magnetron sputtering system. There are less unknown variables with this method in the solving process and the result has high accuracy. This method is better the oretically founded compared with the equivalent source method. The expression of scalar potential function is an analytic series, which favors calculating field intensity and optimization.
Thermal conductivities of different period Si/Ge superlattices
Authors: Liu Ying-Guang , Hao Jiang-Shuai , Ren Guo-Liang , Zhang Jing-Wen ,   School of Energy, Power and Mechanical Engineering, North China Electric Power University, Baoding 071003, China
Published: December 2020

Thermoelectric materials, which can convert wasted heat into electricity, have attracted considerable attention because they provide a solution to energy problems. The Si/Ge superlattices have shown tremendous promise as effective thermoelectric materials. The period lengths of the Si/Ge superlattices can effectively tailor the phonon's transport behaviors and control their thermal conductivities. In this paper, three kinds of Si/Ge superlattices with different period length distributions (uniform, gradient, random) are constructed. The non-equilibrium molecular dynamics (NEMD) method is used to calculate the thermal conductivities of Si/Ge superlattices under the different period length distributions. The effect of the sample’s total length and temperature on the superlattice's thermal conductivity are studied. The simulation result shows that the thermal conductivity of gradient and random periodical Si/Ge superlattices are significantly reduced at room temperature compared with that of the uniform period Si/Ge superlattices. Phonons are transported by wave or particle properties in the different periodical superlattices. The thermal conductivity of uniform period superlattices has an obvious size effect with the increasing of the sample total length. In contrast, the thermal conductivity of gradient, random periodical Si/Ge superlattices are weakly dependent on the sample’s total length. At the same time, temperature is an important factor affecting the heat transport properties. We find that the temperature affects the thermal conductivities of the three kinds of superlattices in different ways. With the increase of the temperature, (i) the thermal conductivity of uniform periodical superlattices shows an obvious temperature effect; (ii) the thermal conductivity of the gradient and random periodical Si/Ge superlattices are nearly unchanged due to the competition between phonon localization weakness and phonon-phonon scattering enhancement. In addition, the phonon densities of states of superlattices with three different periodical length distributions are calculated. We find that in the picture of uniform periodical Si/Ge superlattices, the number of pronounced peaks quickly decreases as the period length increases, particularly at higher frequencies. This indicates that as the period length increases, fewer coherent phonons will be formed over the superlattices. Moreover, the scattering mechanisms of phonons for gradient and random periodical Si/Ge superlattices are basically the same at 100 K and 500 K. These findings provide a developmental way to further reduce the thermal conductivity of superlattices.
PRD-2 directly regulates casein kinase I and counteracts nonsense-mediated decay in the Neurospora circadian clock
Authors: Kelliher Christina M , Lambreghts Randy , Xiang Qijun , Baker Christopher L , Loros Jennifer J , Dunlap Jay C
Published: December 2020

Circadian clocks in fungi and animals are driven by a functionally conserved transcription–translation feedback loop. InNeurospora crassa, negative feedback is executed by a complex of Frequency (FRQ), FRQ-interacting RNA helicase (FRH), and casein kinase I (CKI), which inhibits the activity of the clock’s positive arm, the White Collar Complex (WCC). Here, we show that theprd-2(period-2) gene, whose mutation is characterized by recessive inheritance of a long 26 hr period phenotype, encodes an RNA-binding protein that stabilizes theck-1atranscript, resulting in CKI protein levels sufficient for normal rhythmicity. Moreover, by examining the molecular basis for the short circadian period ofupf-1prd-6mutants, we uncovered a strong influence of the Nonsense-Mediated Decay pathway on CKI levels. The finding that circadian period defects in two classically derived Neurospora clock mutants each arise from disruption ofck-1aregulation is consistent with circadian period being exquisitely sensitive to levels ofcasein kinase I.