bluuebunny/crossref_metadata_2025 huggingface dataset:
An improved ensemble model on current induced magnetic switching effect
Authors: Zhang Lei  , Hu Jiu-Ning  , Ren Min  , Dong Hao  , Deng Ning  , Chen Pei-Yi  ,   清华大学微电子学研究所，北京  100084
Published: December 2020

The current induced magnetic switching (CIMS) effect could occur without the magnetic field in nano-scale pseudo-spin valves that have the potential perspective for application in nonvolatile magnetic random access memory. In this paper, spin transport process in the pseudo-spin valve nanopillars has been investigated with macroscopic double conducting channel diffusion model. Dynamic equation of the magnetization of free layer is established with the consideration of the influence of transverse component of the magnetization vector of free layer. And the boundary conditions of the spin current continuity and chemical-potential-split equality are employed. The critical current in CIMS effect is calculated. The influences of the conductance mismatch of ferromagnetic and nonmagnetic layers and longitudinal applied field on the critical current is interpreted.
Anisotropy of hole effective mass of strained Si/(001)Si1-xGex
Authors: Song Jian-Jun  , Zhang He-Ming  , Xuan Rong-Xi  , Hu Hui-Yong  , Dai Xian-Ying  ,   西安电子科技大学微电子学院，宽禁带半导体材料与器件教育部重点实验室，西安  710071
Published: December 2020

There has been much interest in the Si-based strained materials lately, which was widely adopted in the high-speed and high-performance devices and circuits. Based on the valence band E（k）-k relation of strained Si/（001）Si1-xGex, the hole effective mass along arbitrarily k wavevector direction were obtained. It was found that in comparison with relaxed Si, the obvious change occurs in the hole effective mass of first and second valence band in strained Si/（001）Si1-xGex along specific k wavevector directions. The hole effective mass plays a significant role in the hole mobility enhancement. The results can supply valuable references to the investigation on the Si-based strained PMOS device performance and the conduction channel design related to stress and orientation.
Relaxor ferroelectricity of （1-x）（K0.5Na0.5）NbO3-xSrTiO3 ceramics
Authors: Song Xue-Ping  , Zhang Yong-Guang  , Luo Xiao-Jing  , Xu Ling-Fang  , Cao Wan-Qiang  , Yang Chang-Ping  ,   湖北大学物理学与电子技术学院，铁电压电陶瓷与器件湖北省重点实验室，武汉  430062
Published: December 2020

SrTiO3 doped ceramics of （1-x）（K0.5Na0.5）NbO3-xSrTiO3 （0≤x≤0.15, （1-x）KNN-xST） were prepared using solid state reaction method and the phase components, crystal structure, and dielectric properties were investigated in this work. It is found that all samples （0≤x≤0.15） are single phases with a perovskite structure within the temperature range from 10 to 800 K. The （1-x）KNN-xST compound has the orthorhombic structure when SrTiO3 concentration is below 0.1, while it shows cubic structure when x ≥ 0.1. It changes from the normal ferroelectric phase to ferroelectric relaxors when increasing the SrTiO3 impurity below a certain temperature. The critical temperature of （1-x）KNN-xST decreases dramatically while the FWHM of D and the critical parameter γ increase with increasing SrTiO3. The temperature spectrum of permittivity loss ε″r indicates that the loss duc to relaxor polarization plays the key role at low temperatures, however, the loss duc to current leakage is significant in the region of high temperatures.
Silicon nanopore array structure using porous anodic alumina
Authors: Bai An-Qi  , Hu Di  , Ding Wu-Chang  , Su Shao-Jian  , Hu Wei-Xuan  , Xue Chun-Lai  , Fan Zhong-Chao  , Cheng Bu-Wen  , Yu Yu-De  , Wang Qi-Ming  ,   中国科学院半导体所，集成光电子国家重点实验室，北京  100083
Published: December 2020

A free-standing, bidirectionally permeable and ultra-thin （500—1000 nm） porous anodic alumina membrane was fabricated using a two-step aluminium anodization process, which was then placed on top of a silicon film as an etching mask. The pattern was transferred to silicon using dry-etching technology, and the silicon nanopore array structure was formed. The factors which affict the pattern transfer process are discussed. Observation of the nanopatterned sample under a scanning electron microscope shows that the structure obtained by this method is made up of uniform and highly ordered holes, which attains to 125 nm depth. The photoluminescence spectrum from the nanopatterned sample，the surface of which has been thermal-oxidized, shows that the the luminesce is evidently enhanced, the mechanism of which is based on the normally weak TO phonon assisted bandgap light-emission process, and the physical reasons that underlic the enhancement have been analyzed. The PL results do show an attractive optical characteristic, which provides a promising pathway to achieve efficient light emission from silicon.
Entanglement evolution of field-atom and atom-atom in Tavis-Cummings model
Authors: Guo Liang  , Liang Xian-Ting  ,   宁波大学近代物理研究所与物理系，宁波  315211
Published: December 2020

In this paper we have investigated the entanglement evolutions between a two-level atom and a single-mode field as well as two two-level atoms in different W-like initial states in T-C model. It is shown that the evolutions of the formation entanglement between them are periodical, and the periods of the entanglement evolutions are different according to the difference of the initial states.The so-called sudden death of entanglement occures between two atoms as the initial states is some W-like initial state.
Study on the model of quantum efficiency of reflective varied doping GaAs photocathode
Authors: Niu Jun  , Yang Zhi  , Chang Ben-Kang  , Qiao Jian-Liang  , Zhang Yi-Jun  ,   (1)南京理工大学电子工程与光电技术学院,南京  210094; (2)南京理工大学电子工程与光电技术学院,南京  210094；南阳理工学院电子与电气工程系，南阳  473004
Published: December 2020

The theoretical model of quantum efficiency of the reflective varied doping GaAs photocathode is proposed, which adopts the weighted mean method based on the quantum efficiency formula of exponential doping and uniform doping photocathode. By this model the quantum efficiency curves of a reflective GaAs photocathode under varied doping structure have been fit and we obtained the precise best fit in different incident photon wavebands. The phenomena that the contributions of doping structures to the cathode quantum efficiency are different was discovered. This phenomena has been analysed and discussed detailedly in the paper.
Multiple clusters echo state network for chaotic time series prediction
Authors: Song Qing-Song  , Feng Zu-Ren  , Li Ren-Hou  ,   西安交通大学系统工程研究所，西安  710049
Published: December 2020

The chaotic time series prediction problem is considered. A novel type of cortex-like neural network model, i.e. multi-clusters echo state network model （MCESN）, regulated by a group of five growth-factors, is proposed. It is shown that characters of MCESN’ topology can be effectively determined by the growth-factors group; and that it is the MCESN possessing both small-world and scale-free properties of complex network that corresponds to the better prediction performance. In addition, Monte Carlo simulation experiments show that MCESN not only can be trained by easy algorithm, but also can achieve higher accuracy and less standard deviation prediction results than classical echo state networks.
Charge-carrier transport properties of blend film of Alq3 and CdSeS quantum dot
Authors: Zhang Shu-Ping  , Yang Ze-Chao  , Peng Ya-Jing  , Wang Ying-Hui  , Liu Yu-Qiang  , Yang Yan-Qiang  ,   哈尔滨工业大学物理系凝聚态科学与技术研究中心，哈尔滨  150001
Published: December 2020

The charge-carrier mobility of the blend films consisting of organic small molecule and quantum dots (QDs)，Alq3 and CdSeS，are studied by time-of-flight (TOF) technique. The dependence of charge-carrier mobility in the blend films on electric filed and QD concentration is measured. The results show that the positional disorder in the blend films are increased with the increase of QD concentration. Moreover，the charge transport mechanisms between Alq3 and QDs and the number of electron hoppings between QDs will lead to the change of the charge-carrier mobility.
Restriction of geometrical frustration and magnetic ordering in the inverse-spinel LiNiVO4
Authors: Du Fei  , Li Xu  , Huang Zu-Fei  , Li Ang  , Wang Chun-Zhong  , Chen Gang  ,   吉林大学材料科学与工程学院，长春  130012
Published: December 2020

The magnetic properties of inverse-spinel LiNiVO4 have been investigated. It is found that there is a strong spin-orbit coupling effect in the system via fitting the paramagnetic data at high-temperature portion. A short-range antiferromagnetic ordering shows at low temperature with Neel temperature 35 K，which results from the restriction of the geometrical frustration due to the random distribution of Li+/Ni2+ ions.
Magnetoelectric response of magnetostrictive/piezoelectric composite on a trapezoidal elastic substrate
Authors: Zhang Yan-Fang  , Wen Yu-Mei  , Li Ping  , Bian Lei-Xiang  ,   重庆大学光电工程学院，教育部光电技术及系统重点实验室，重庆  400030
Published: December 2020

A magnetostrictive /elastic substrate /piezoelectric composite has been developed where the elastic substrate takes the form of trapezium to amplify the strain. By using the equivalent circuit, the magnetoelectric response of the composite in the longitudinal vibration has been analyzed. The magnetoelectric response of a Terfenol-D/trapezoidal Be-bronze/PZT-5H composite is calculated and is compared with the experiment. It is indicated that the theoretical response shows a similar variation tendency as the experimental in spite of the difference in resonant frequencies and the values of the magnetoelectric voltage coefficients, which is the result of neglecting the glue behavior. At the same time, the composite on a trapezoidal substrate and the composite on a rectangular substrate are compared, which indicates that the former has higher magnetoelectric voltage coefficient. The length ratio of the trapezoidal elastic substrate and the thickness ratio of the composite are further analyzed. It is found that the composite will have maximum magnetoelectric voltage coefficient when: (1) the ratio of the length of wide section to the total length of a trapezoidal elastic substrate is 0.45; (2) the thickness of a trapezoidal elastic substrate is one fourth that of Terfenol-D layer.
Effect of hydrogen dilution on crystalline properties of nano-crystalline silicon thin films in fast growth
Authors: Qiu Sheng-Hua  , Chen Cheng-Zhao  , Liu Cui-Qing  , Wu Yuan-Dan  , Li Ping  , Lin Xuan-Ying  , Huang Chong  , Yu Chu-Ying  ,   (1)韩山师范学院物理与电子工程系,潮州  521041; (2)韩山师范学院物理与电子工程系,潮州  521041；汕头大学物理系,汕头  515063; (3)汕头大学物理系,汕头  515063
Published: December 2020

Nano-crystalline silicon films were prepared from SiH4 diluted with hydrogen by plasma enhanced chemical vapor deposition at a pressure of 230 Pa. The effect of hydrogen dilution on their growth rate and crystalline properties were investigated. The experimental results indicate that the crystalline fraction and grain size increase with increasing hydrogen dilution ratio, and when the hydrogen dilution ratio increases to 99%, the crystalline fraction reaches 70%. The deposition rate decreases with increasing hydrogen dilution ratio, when the hydrogen dilution ratio decreases from 99% to 95%, the deposition rate of thin film increases from 0.3nm/s to 0.8nm/s.
Characterization of rapidly solidified Cu-Pb hypermonotectic alloys
Authors: Xu Jin-Feng  , Fan Yu-Fang  , Chen Wei  , Zhai Qiu-Ya  ,   西安理工大学材料科学与工程学院，西安  710048
Published: December 2020

The microstructural characteristics of rapid solidified Cu-Pb hypermonotectic alloys were investigated by melt-spun method, the electrical resistivity and mechanical properties of the alloys were characterized, and the relationships between cooling rate and microstructural morphology as well as the properties of the alloys were analyzed theoretically. Results show that, under rapid solidification, (Cu) and (Pb) phases grow in the form of dendrite, which is characterized by uniform and fine equiaxied grain. With the rise of cooling rate, the equiaxied grain is refined remarkably, the amount of grain boundaries increase, the scattering of free electrons is intensified, leading to the increases of electrical resistivity. Meanwhile, the tensile strength of alloy foils increases linearly, but the elongation of alloys decreases.
An investigation of the lamellar-rod transition in binary eutectic using 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

The KKSO multi-phase field model is employed to simulate the lamellar-rod transition with different pulling velocities and different solute diffuse coefficients in liquid. The simulation results show that the eutectic keeps lamellar growth after lamellar merging at small pulling velocity. With an increase of the pulling velocity, the lamellar eutectic transits to rod-like eutectic after lamellar merging. And the further increase of the pulling velocity will make the lamellar grow steadily with its initial lamellar spacing. It's also found that the simulations of different solute diffusion coefficients in liquid are similar to those of different velocities and the transition from lamellar eutectic to rod-like takes place only in a certain range of each parameter. All of the simulated results are in agreement with the experiments qualitatively.
Thermal dynamic analysis of picosecond and nanosecond single pulse laser flash-heating of Al/NC nanoenergetic composites
Authors: Peng Ya-Jing  , Liu Yu-Qiang  , Wang Ying-Hui  , Zhang Shu-Ping  , Yang Yan-Qiang  ,   哈尔滨工业大学物理系凝聚态科学与技术研究中心，哈尔滨  150001
Published: December 2020

Thermal dynamic process of single pulse laser-induced reaction is theoretically analyzed for a novel system of composite energetic materials containing nanometallic particles. The instantaneous power density of laser energy absorbed by nanometallic particles dispersed in a matrix is exactly deduced. The process of absorbing pulse laser energy for nanometallic aluminum particles embedded in nitrocellulose (Al/NC) thin film and the heat propagation process of hot spot accompanying exothermic chemical reaction are simulated numerically based on thermal decomposition mechanism. The reaction diameters are calculated for different concentrations of Al/NC thin films flashed by 100ps, 10ns and 25ns single pulse laser with the reaction threshold intensities having been obtained from experiment, respectively. Calculation results are compared with the experiment data, which shows that the thermal decomposition mechanism generally corresponds to the reaction processes of 10ns and 25ns pulse laser but does not correspond to that of the 100ps pulse laser.
Effects of the thickness of spacing layer and capping layer on the strain distribution and wavelength emission of InAs/GaAs quantum dot
Authors: Liu Yu-Min  , Yu Zhong-Yuan  , Ren Xiao-Min  ,   (1)北京邮电大学，理学院，北京  100876；光通信与光波技术教育部重点实验室(北京邮电大学)，北京  100876; (2)光通信与光波技术教育部重点实验室(北京邮电大学)，北京  100876
Published: December 2020

A systematic investigation is given about the influence of thickness of the spacing layer on the strain distribution during the capping stage of the quantum dot. The calculated results show that the mismatch between the lattice constant of the spacing layer along the growth direction and that of the quantum dot is very important for the the strain distribution. The height of the quantum dot is compressed during the capping stage, which is qualitatively interpreted form the strain distributions. When the thickness of the spacing layer equals the quantum dot, the influence of thickness of the capping layer on strain distribution is also discussed. Based on the deformation potential theory, the dependence of the emission wavelength on the thickness of the capping layer is investigated. The calculated results agree well with the experiment results. We conclude that, during the capping stage of the quantum dot, the strain is very critical for both the shape of the quantum dot and the optical characteristics; extension of the emission wavelength via quantum dot strain engineering is an effective means.
Geant 4-based calculation of electric field in deep dielectric charging
Authors: Qin Xiao-Gang  , He De-Yan  , Wang Ji  ,   (1)兰州大学物理科学与技术学院，兰州  730000; (2)兰州大学物理科学与技术学院，兰州  730000；真空低温技术与物理国家重点实验室，兰州  730000; (3)真空低温技术与物理国家重点实验室，兰州  730000
Published: December 2020

Based on Geant4 particle transfer simulation, the internal current density, dose rate and charge deposition profiles of Teflon are acquired, and then the electric field under high energy and low density e-beam radiation is calculated with radiation-induced conductivity model of charging dynamics, which includes the continuity equation, Poisson equation and deep trap equation. According to Geant4 package, the charging model of dielectric is simplified as a compound structure consisting of shielding aluminum and multiple-layer plates radiated by 1.0MeV energy and 0.1 pA/cm2 flux density surface source. With statistical method, the distributions of internal current density, dose rate and charge deposition are obtained and normalized with the above flux density. Substituting these results into RIC model, the distributions of electric field in Teflon are calculated under various grounding conditions. It shows that the charge density, electric field and potential for the back side grounding are higher than these for the front side grounding, which tends to induce internal discharging. The electric field calculated for the critical internal discharging conditions in space is also consistent with the threshold field of dielectric Teflon(1e7V/m).
A new method of calculating the deflection of light by gravitational field
Authors: Ren Ji-Rong  , Zhu Hui  ,   兰州大学理论物理研究所，兰州  730000
Published: December 2020

In this paper, we tried to find the relation between the deflection angle of light in the geometrical optic approximation of electromagnetic wave and wave vector according to the quantum theory of light, the energy conservation principle, and the weak equivalence principle. Using the electromagnetic wave equation in gravitational field, we give a general method of calculating the deflection of light by gravitational field under the condition of weak field approximation. Finally, the deflection angles in Schwarzchild metric and Kerr-Newman metric are calculated.
Time-integral theorems for generalized Birkhoff system
Authors: Ge Wei-Kuan  , Mei Feng-Xiang  ,   (1)北京理工大学力学系,北京  100081; (2)湖州师范学院物理系,湖州  313000
Published: December 2020

The purpose of this paper is to study the time-integral theorems for a generalized Birkhoff system. A time-integral identity of the system is presented. A power-like equation，a Virial-like theorem，an integral variational principle and a differential variational principle for the system are deduced by using the time-integral identity.
Existence of oscillatory travelling wave solution of flood wave with viscosity
Authors: Zhang Liang  , Zhang Li-Feng  , Wu Hai-Yan  , Wang Ji-Peng  ,   (1)94855部队，衢州  324001; (2)解放军理工大学气象学院应用地球物理研究室,南京  211101; (3)解放军理工大学气象学院应用地球物理研究室,南京  211101；96165部队,乐平  333300; (4)总参气象水文局，北京  100081
Published: December 2020

Using the shooting technique, we investigate the existence of oscillatory travelling wave solution of viscous flood wave in a wide rectangular channel with constant inclination. We prove the existence and uniqueness of an oscillatory travelling wave solution when the parameters of the viscous coefficient, frictional coefficient, inclination and altitudinal ratio satisfy certain conditions. Owing to the difficulty of analytical calculation, Matlab is used to compute the value of altitudinal ratio, and the structure of oscillatory travelling wave solution is also discussed.
An analysis of the model of the error bits of quantum cryptography protocol
Authors: Zhang Sheng  , Wang Jian  , Zhang Quan  , Tang Chao-Jing  ,   国防科学技术大学电子科学与工程学院，长沙  410073
Published: December 2020

Quantum cryptography protocols have the feature of unconditional security, which is ensured by attack-detection. A new method is introduced to improve the precision of the estimation of the error rate in the information bits. With the new technique, more information about the error bits can be obtained, then the value of error rate of the information bits can be obtained by classical signal estimation. This method can improve the precision of attack-detection within a single running of all quantum cryptography protocols.
Statistical entropy of Gibbons-Maeda black hole computed by generalized uncertainty principle
Authors: He Feng  , Zhao Fan  ,   湖南科技大学物理学院，湘潭  411201
Published: December 2020

Statistical entropy of scalar field outside Gibbons-Maeda black hole is computed by the equation of state density corrected by the generalized uncertainty principle and by WKB approximation method. The result shows that the black hole entropy is proportional to its horizon area, which is the same as that given by Brick-Wall method. The difference from the Brick-Wall method is that the present result is convergent without any cutoff.
Fermions tunneling of the Vaidya-Bonner black hole
Authors: Lin Kai  , Yang Shu-Zheng  ,   西华师范大学理论物理研究所，南充  637002
Published: December 2020

The Hawking radiation of the Vaidya-Bonner black hole is studied by the theory of fermions tunnelling. By applying the following coordinate transformation and assuming proper γμ matrixes, we study the tunneling characteristics of the fermions with 1/2 spin from the Vaidya-Bonner black hole.
Phase synchronization of coupling systems
Authors: Liu Yong  ,   盐城师范学院数学科学学院，盐城  224051
Published: December 2020

The influence of the linear and nonlinear coupling parameters on the phase synchronization of chaos between two sub-systems with primary resonance is investigated by introducing the conception of the phase for a chaotic motion. The evolution process from non-synchronized state to imperfect phase synchronization and further to perfect phase synchronization between two sub-systems with approximate primary resonance is discussed. Further investigation reveals that the transition between different phase states are related to the critical change of the Lyapunov exponents. The results show that phase synchronization between two sub-systems is enhanced with the increase of the linear coupling strength and decayed with the increase of nonlinear coupling strength.
An attractor with invariable Lyapunov exponent spectrum and its Jerk circuit implementation
Authors: Li Chun-Biao  , Wang De-Chun  ,   (1)南京理工大学电子工程与光电技术学院，南京  210094; (2)南京理工大学电子工程与光电技术学院，南京  210094；江苏经贸职业技术学院工程技术系，南京  210007；江苏省食品安全工程技术研究开发中心电源与系统部，南京  210007
Published: December 2020

A novel three-dimensional chaotic attractor derived from Colpitts equation is proposed in this paper. When the given parameter varies in a broad range, the amplitude of the singals of the first two dimensions changes linearitly while the third one keeps its amplitude in the same range. At the same time, the Lyapunov exponent spectrum keeps invariable. This chaotic system is developed by substituting the absolute term for the exponent term in normalized Colpitts equation. Lyapunov exponent, Poincaré mapping, phase portrait and spectrum are given to verify that the attractors are chaotic. In addition, some basic dynamical characteristics of the new system are investigated briefly. Based on Lyapunov exponent spectrum analysis, it is demonstrated that the new system can go into periodic and chaotic behaviors. At last, the Jerk function of the new system is put forward and its circuit implementation is designed. The feature that the chaotic characteristic of this system has nothing to do with the given parameter while the amplitude of some state variables can be changed linearly makes it reasonable to predict that the chaotic system will have tremendous potential applications in chaotic radar, secure communications and other information processing systems.
Linear and nonlinear generalized synchronization of a class of chaotic systems by using a single driving variable
Authors: Li Jian-Fen  , Li Nong  , Liu Yu-Ping  , Gan Yi  ,   (1)空军工程大学工程学院，西安  710038; (2)空军工程大学理学院，西安  710051
Published: December 2020

By designing a suitable response system to a class of chaotic systems, we realise the linear and nonlinear generalized synchronizations for these chaotic systems by only transmitting a single variable. The method of obtaining the response system from chaotic system is proposed. Since chaos synchronization can be achieved by transmitting the single variable from driving system to response system, this method is more practical. Theoretical deduction and computer simulation show the effectiveness of the proposed method.
Detection of ship targets on the sea surface based on Lyapunov exponents of image block
Authors: He Si-Hua  , Yang Shao-Qing  , Shi Ai-Guo  , Li Tian-Wei  ,   (1)海军大连舰艇学院航海系，大连  116018; (2)海军大连舰艇学院航海系，大连  116018；海军92493部队，葫芦岛  125001; (3)海军大连舰艇学院信息与通信工程系，大连  116018
Published: December 2020

The change of background's chaos feature when there are moving targets was analysed, and a new algorithm based on Lyapunov exponents of image block for moving targets detection on the sea surface, which is used for ship targets detection on the sea surface, was proposed. The new method defines the term of image gray level distance, extends the calculation method of Lyapunov exponents from single dimension signal to image signal based on the improved Wolf method, uses the change of the largest gray level distance Lyapunov exponents to detect ship targetssubmerged in chaos background. Experimental results show that the sea surface background has chaos feature. The proposed algorithm can detect ship targets effectively and can get better result than statistical analysis.
Anti-synchronization of nonlinear-coupled spatiotemporal chaotic systems
Authors: Lü Ling  , Xia Xiao-Lan  ,   辽宁师范大学物理与电子技术学院,大连  116029
Published: December 2020

The anti-synchronization of two nonlinear-coupled spatiotemporal chaotic systems is discussed. A special nonlinear-coupled term is constructed through suitably separating the spatiotemporal chaotic systems to linear and nonlinear terms, and anti-synchronization of two two-dimensional coupled map lattices is realized. The nonlinear-coupled method is further generalized to anti-synchronize the complex networks composed of two-dimensional coupled map lattices. The artificial simulation results show that this method is still effective.
Surface dry treatment of RF superconducting cavity by sputtering
Authors: Zhu Feng  , Jiao Fei  , Quan Sheng-Wen  , Hao Jian-Kui  , Zhao Kui  ,   北京大学核物理与核技术国家重点实验室，重离子物理研究所，北京  100871
Published: December 2020

We have developed a new technique of surface treatment of RF superconducting cavity by sputtering under ultra high vacuum. In this paper，impacts of sputtering treatment on the surface properties of niobium sample and niobium cavity are analysed in detail. Compared with the traditional “wet" cavity treatment (buffered chemical polishing and electro-polishing)，this dry treatment is simple，easy to control，less costly and without pollution. It is a potential superconducting cavity surface treatment method and can improve the performance of the cavity.
Lead-tin-fluorophosphates scintillating glass doped with stilbene 420 excited by gamma ray
Authors: Xia Liang-Bin  , Ouyang Xiao-Ping  , Wang Qun-Shu  , Kang Ke-Jun  , He Xiao-Ling  , Gu Mu  ,   (1)清华大学工程物理系，北京  100084; (2)清华大学工程物理系，北京  100084；西北核技术研究所，西安  710024; (3)同济大学玻耳固体物理研究所，上海  200092; (4)西北核技术研究所，西安  710024
Published: December 2020

Lead tin fluorophosphates (PTFP) glass doped with organic dye stilbene 420 is prepared. The melting temperature of the doped glass is below 250℃，and the characteristic temperature is about 75℃. The luminescence excited by 60Co 1.25MeV gamma ray is measured，and is compared with organic scintillator ST401 with the same thickness. The scintillation of doped PTFP glass is from 1 to 2 percent that of ST401.
Effect of high static magnetic field and AC current on solidification of Zn-30wt%Bi monotectic alloy
Authors: Wang Jiang  , Zhong Yun-Bo  , Ren Wei-Li  , Lei Zuo-Sheng  , Ren Zhong-Ming  , Xu Kuang-Di  ,   上海大学上海市现代冶金与材料制备重点实验室，上海  200072
Published: December 2020

Effect of high static magnetic field (HSMF) coupled with AC current of different intensities and frequencies on solidification morphology of Zn-30wt%Bi monotectic alloy was studied. The gravity segregation of Zn-30wt%Bi monotectic alloy could not be suppressed thoroughly only by superimposing AC current or 10T HSMF separately at the cooling rate of 25℃/min. When the 10T HSMF and 50Hz AC current were superimposed simultaneously，the induced alternate Lorentz force could reduce the gravity segregation remarkably. More homogeneous solidification morphology could be obtained when increasing the AC current density，magnetic flux density or current frequency separately. However，each of the above-mentioned three parameters has its own optimum value on deviating from which the homogeneous distribution morphology could not be obtained. The mechanism on the coupled fields affecting the gravity segregation of Zn-30wt%Bi monotectic was discussed based on the magneto-hydrodynamic theory. The results reveal that it is possible to manufacture homogeneous monotectic alloy under normal gravity surroundings and at a low cooling rate by superimposing coupled fields in the solidification process.
The scalar force network ensemble model for force distribution in granular system
Authors: Zhang Xing-Gang  , Long Zheng-Wen  , Hu Lin  ,   贵州省光电子技术与应用重点实验室，贵州大学理学院，贵阳  550025
Published: December 2020

A scalar model of force network ensemble is proposed to investigate the force distribution in static granular system. The Laplace transform method is found as an effective method to solve the integral issue of probability density under complex constraints. On the condition that the system has few layers, the analytical expression for the limit distribution is accounted for which is the product of the polynomial function and the exponential function. When the force is near the average force, the distribution has its maximum value, when it's above the average force, the distribution decreases exponentially.
Terahertz antenna based on the carbon nano-tube in the nano-scopic domain
Authors: Wang Yue  , Wu Qun  , Shi Wei  , He Xun-Jun  , Yin Jing-Hua  ,   (1)哈尔滨工业大学电子与信息技术研究院，哈尔滨  150001; (2)哈尔滨工业大学电子与信息技术研究院，哈尔滨  150001；哈尔滨理工大学电子科学与技术系，哈尔滨  150080; (3)哈尔滨理工大学电子科学与技术系，哈尔滨  150080; (4)西安理工大学超快光电技术研究中心，西安  710048
Published: December 2020

A novel nano-antenna for the generation and applications of terahertz wave and the Pocklingtons integral equation are proposed based on the carbon nanotube structure. The radiation characteristics of carbon nanotube antenna in terahertz range have been investigated by numerical simulation and theoretical computation. Both the numerical and analytical results demonstrate that the antenna with half wave length of 60μm takes on the dual frequency properties at the center frequencies of 2.5THz and 7.6THz，with the corresponding -10dB return loss (S11) bandwidths of 8.4% and 2.7%，respectively. Compared with the gain of 0.598dB of a single dipole antenna the maximum gain of a typical 10×10 carbon nanotube antenna array is 10.30dB. The results could be useful for the design of carbon nanotube antenna arrays for generating terahertz wave.
Q-switched pulse polarization-maintaining Nd3+-doped fiber laser
Authors: Ren Guang-Jun  , Wei Zhen  , Yao Jian-Quan  ,   (1)天津大学精密仪器与光电子工程学院，激光与光电子研究所，光电信息科学技术教育部重点实验室，天津  300072; (2)天津理工大学电子信息与通信工程学院，薄膜电子与通信器件天津市重点实验室，通信器件与技术教育部工程研究中心，天津  300191; (3)天津理工大学电子信息与通信工程学院，薄膜电子与通信器件天津市重点实验室，通信器件与技术教育部工程研究中心，天津  300191；天津大学精密仪器与光电子工程学院，激光与光电子研究所，光电信息科学技术教育部重点实验室，天津  300072
Published: December 2020

The Nd3+-doped pulse polarization-maintaining fiber laser pumped by 808nm semiconductor laser is investigated experimentally and theoretically. The wave form of output pulse was detected by a TDS5104 oscillograph，and the spectrogram of the output pulse was obtained by using a spectrum analysis apparatus. Originally，the single pulse energy of 2.3mJ with average power of 2.55W was generated at the repetition rate of 1kHz. By changing the resonance cavity and making other modificantions of the laser, we obtained the highest single pulse energy of 3.3mJ with peak power of 17.9kW at the repetition rate of 1kHz，and the pulse width was 184ns and the average power of the output pulse was 3.5W.
Properties of Cassegrain optical antenna with inclined optical axis
Authors: Ran Ying-Hua  , Yang Hua-Jun  , Xu Quan  , Xie Kang  , Huang Jin  ,   (1)电子科技大学光电信息学院，成都  610054; (2)电子科技大学物理电子学院，成都  610054
Published: December 2020

A Cassegrain optical antenna with parabolic structure is designed. By detailed analysis of Cassegrain optical antenna in partial axis situation，the expression of the area of the receiving spot and the power decline curve are obtained for different deflection angles. The relations between the received antenna gain and the wavelength and deflection angles are discussed in partial axis situation，the curves of gain for partial axis and axis alignment are simulated. The simulation result indicates that the gain of the maximal partial axis decreases by 6.564dB compared with that of axis alignment. Experiments of the optical spot test and the antenna coupling efficiency test are carried out separately for axis alignment and certain partial axis situations. The results show that the antenna coupling efficiency under partial axis situation is 26.97% lower than that of axis alignment. This study will provide a theoretical foundation for the control system to realise perfect alignment of optical axis in inter-satellite optical communications.
Chaotic parallel synchronization of optoelectronic feedback semiconductor lasers
Authors: Fan Li  , Xia Guang-Qiong  , Wu Zheng-Mao  ,   (1)西南大学物理学院，重庆  400715; (2)西南大学物理学院，重庆  400715；南开大学弱光非线性光学教育部重点实验室，天津  300457
Published: December 2020

A chaotic parallel synchronization model of optoelectronic feedback semiconductor lasers is proposed. The complete synchronization and generalized synchronization are studied，while the effect of intrinsic parameter mismatch on the difference in the synchronization performances between the drive laser and receive laser or between the parallel receive lasers is emphatically discussed. The results show that zero-time-lag complete synchronization between the drive laser and parallel receive laser can be realised under parameter match. For generalized synchronization，if one of the intrinsic parameters of the receive laser is changed，the cross correlation between the parallel receive lasers is larger than thatbetween the drive laser and the receive laser over a wide parameter mismatch range.
Competition between the excited-state refraction and excited-state absorption induced transient thermal refraction of metallic porphyrin compound
Authors: Chen Yu-Ming  , Wang Yu-Xiao  , Jiang Li  , Zhang Xue-Ru  , Yang Jun-Yi  , Li Yu-Liang  , Song Ying-Lin  ,   (1)哈尔滨工业大学应用物理系，哈尔滨  150001; (2)苏州大学物理科学与技术学院，苏州  215006; (3)中国科学院化学研究所有机固体重点实验室，北京国家分子科学实验室，北京  100190
Published: December 2020

The competition between the excited-state absorption induced transient thermal refraction and the excited-state refraction of a novel metallic porphyrin compound Zn-porphyrin was studied by the excited-state absorption induced transient thermal refraction theory combined with the excited-state refraction theory. The transformation between self-focusing and self-defocusing of the sample for different pulse widths was observed. The sample exhibited self-focusing effect attributed mainly to excited-state refraction for 4 ns laser pulse, while in the self-defocusing effect for 8 ns laser pulse the excited-state absorption induced transient thermal refraction dominates the excited-state refraction.
Bizarre Parosteal Osteochondromatous Proliferation (Nora's Lesion) in the Medial Sesamoid of the First Toe
Authors: Tetik Onur , Aslan Lercan , Buyukdogan Kadir , Chodza Mehmet , Kilicoglu Onder
Published: December 2020

Bizarre parosteal osteochondromatous proliferation, or Nora's lesion, is a unique bony lesion that generally originates from the small bones of the hands and feet in young adults. We report a case of a bizarre parosteal osteochondromatous proliferation originating from the medial sesamoid of the first toe that was managed surgically by en bloc excision. At 5-year follow-up, there was no evidence of recurrence.
Vanishing white matter disease expression of truncated EIF2B5 activates induced stress response
Authors: Keefe Matthew D , Soderholm Haille E , Shih Hung-Yu , Stevenson Tamara J , Glaittli Kathryn A , Bowles D Miranda , Scholl Erika , Colby Samuel , Merchant Samer , Hsu Edward W , Bonkowsky Joshua L
Published: December 2020

Vanishing white matter disease (VWM) is a severe leukodystrophy of the central nervous system caused by mutations in subunits of the eukaryotic initiation factor 2B complex (eIF2B). Current models only partially recapitulate key disease features, and pathophysiology is poorly understood. Through development and validation of zebrafish (Danio rerio) models of VWM, we demonstrate that zebrafish eif2b mutants phenocopy VWM, including impaired somatic growth, early lethality, effects on myelination, loss of oligodendrocyte precursor cells, increased apoptosis in the CNS, and impaired motor swimming behavior. Expression of human EIF2B2 in the zebrafish eif2b2 mutant rescues lethality and CNS apoptosis, demonstrating conservation of function between zebrafish and human. In the mutants, intron 12 retention leads to expression of a truncated eif2b5 transcript. Expression of the truncated eif2b5 in wild-type larva impairs motor behavior and activates the ISR, suggesting that a feed-forward mechanism in VWM is a significant component of disease pathophysiology.
TFEB/Mitf links impaired nuclear import to autophagolysosomal dysfunction in C9-ALS
Authors: Cunningham Kathleen M , Maulding Kirstin , Ruan Kai , Senturk Mumine , Grima Jonathan C , Sung Hyun , Zuo Zhongyuan , Song Helen , Gao Junli , Dubey Sandeep , Rothstein Jeffrey D , Zhang Ke , Bellen Hugo J , Lloyd Thomas E
Published: December 2020

Disrupted nucleocytoplasmic transport (NCT) has been implicated in neurodegenerative disease pathogenesis; however, the mechanisms by which disrupted NCT causes neurodegeneration remain unclear. In a Drosophila screen, we identified ref(2)P/p62, a key regulator of autophagy, as a potent suppressor of neurodegeneration caused by the GGGGCC hexanucleotide repeat expansion (G4C2 HRE) in C9orf72 that causes amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We found that p62 is increased and forms ubiquitinated aggregates due to decreased autophagic cargo degradation. Immunofluorescence and electron microscopy of Drosophila tissues demonstrate an accumulation of lysosome-like organelles that precedes neurodegeneration. These phenotypes are partially caused by cytoplasmic mislocalization of Mitf/TFEB, a key transcriptional regulator of autophagolysosomal function. Additionally, TFEB is mislocalized and downregulated in human cells expressing GGGGCC repeats and in C9-ALS patient motor cortex. Our data suggest that the C9orf72-HRE impairs Mitf/TFEB nuclear import, thereby disrupting autophagy and exacerbating proteostasis defects in C9-ALS/FTD.
HIV-1 Vpr antagonizes innate immune activation by targeting karyopherin-mediated NF-κB/IRF3 nuclear transport
Authors: Khan Hataf , Sumner Rebecca P , Rasaiyaah Jane , Tan Choon Ping , Rodriguez-Plata Maria Teresa , Van Tulleken Chris , Fink Douglas , Zuliani-Alvarez Lorena , Thorne Lucy , Stirling David , Milne Richard SB , Towers Greg J
Published: December 2020

HIV-1 must replicate in cells that are equipped to defend themselves from infection through intracellular innate immune systems. HIV-1 evades innate immune sensing through encapsidated DNA synthesis and encodes accessory genes that antagonize specific antiviral effectors. Here, we show that both particle associated, and expressed HIV-1 Vpr, antagonize the stimulatory effect of a variety of pathogen associated molecular patterns by inhibiting IRF3 and NF-κB nuclear transport. Phosphorylation of IRF3 at S396, but not S386, was also inhibited. We propose that, rather than promoting HIV-1 nuclear import, Vpr interacts with karyopherins to disturb their import of IRF3 and NF-κB to promote replication in macrophages. Concordantly, we demonstrate Vpr-dependent rescue of HIV-1 replication in human macrophages from inhibition by cGAMP, the product of activated cGAS. We propose a model that unifies Vpr manipulation of nuclear import and inhibition of innate immune activation to promote HIV-1 replication and transmission.
Kinetic sculpting of the seven stripes of the Drosophila even-skipped gene
Authors: Berrocal Augusto , Lammers Nicholas C , Garcia Hernan G , Eisen Michael B
Published: December 2020

We used live imaging to visualize the transcriptional dynamics of theDrosophila melanogaster even-skippedgene at single-cell and high-temporal resolution as its seven stripe expression pattern forms, and developed tools to characterize and visualize how transcriptional bursting varies over time and space. We find that despite being created by the independent activity of five enhancers,even-skippedstripes are sculpted by the same kinetic phenomena: a coupled increase of burst frequency and amplitude. By tracking the position and activity of individual nuclei, we show that stripe movement is driven by the exchange of bursting nuclei from the posterior to anterior stripe flanks. Our work provides a conceptual, theoretical and computational framework for dissecting pattern formation in space and time, and reveals how the coordinated transcriptional activity of individual nuclei shapes complex developmental patterns.
Epidermal PAR-6 and PKC-3 are essential for larval development of C. elegans and organize non-centrosomal microtubules
Authors: Castiglioni Victoria G , Pires Helena R , Rosas Bertolini Rodrigo , Riga Amalia , Kerver Jana , Boxem Mike
Published: December 2020

The cortical polarity regulators PAR-6, PKC-3, and PAR-3 are essential for the polarization of a broad variety of cell types in multicellular animals. InC. elegans, the roles of the PAR proteins in embryonic development have been extensively studied, yet little is known about their functions during larval development. Using inducible protein degradation, we show that PAR-6 and PKC-3, but not PAR-3, are essential for postembryonic development. PAR-6 and PKC-3 are required in the epidermal epithelium for animal growth, molting, and the proper pattern of seam-cell divisions. Finally, we uncovered a novel role for PAR-6 in organizing non-centrosomal microtubule arrays in the epidermis. PAR-6 was required for the localization of the microtubule organizer NOCA-1/Ninein, and defects in anoca-1mutant are highly similar to those caused by epidermal PAR-6 depletion. As NOCA-1 physically interacts with PAR-6, we propose that PAR-6 promotes non-centrosomal microtubule organization through localization of NOCA-1/Ninein.
Fixed‐time adaptive neural tracking control for a class of uncertain multi‐input and multi‐output nonlinear pure‐feedback systems
Authors: He Cheng , Wu Jian , Dai Jiyang , Zhang Zhe
Published: December 2020

This study examines the fixed‐time adaptive neural network tracking control problem for a class of unknown multi‐input and multi‐output (MIMO) nonlinear pure‐feedback systems. The introduction of the radial basis function resolves uncertain problems of unknown MIMO systems. The mean value theorem is introduced to overcome the controller design problem attributed to the nonaffine structure in pure‐feedback systems. Moreover, a novel fixed‐time virtual controller and an actual controller are designed to solve the issue of previous single‐input and single‐output and MIMO systems that have no solution in the negative domain and at the origin in finite‐ and fixed‐time controls. Furthermore, a design method is proposed. The final designed controller ensures that all signals in the system are bounded. Simulation experiments show that the designed fixed‐time controller facilitates smaller tracking error of the system compared with other finite‐ or fixed‐time controllers. Furthermore, the selection of appropriate design parameters allows the tracking error to converge on a small neighborhood of the origin in a fixed time.
Revealing the Degradation and Self‐Healing Mechanisms in Perovskite Solar Cells by Sub‐Bandgap External Quantum Efficiency Spectroscopy
Authors: Cheng Yuanhang , Liu Xixia , Guan Zhiqiang , Li Menglin , Zeng Zixin , Li Ho‐Wa , Tsang Sai‐Wing , Aberle Armin Gerhard , Lin Fen
Published: December 2020

Ion dissociation has been identified to determine the intrinsic stability of perovskite solar cells (PVSCs), but the underlying degradation mechanism is still elusive. Herein, by combining highly sensitive sub‐bandgap external quantum efficiency (s‐EQE) spectroscopy, impedance analysis, and theoretical calculations, the evolution of defect states in PVSCs during the degradation can be monitored. It is found that the degradation of PVSCs can be divided into three steps: 1) dissociation of ions from perovskite lattices, 2) migration of dissociated ions, and 3) consumption of I− by reacting with metal electrode. Importantly, step (3) is found to be crucial as it will accelerate the first two steps and lead to continuous degradation. By replacing the metal with more chemically robust indium tin oxide (ITO), it is found that the dissociated ions under light soaking will only saturate at the perovskite/ITO interface. Importantly, the dissociated ions will subsequently restore to the corresponding vacancies under dark condition to heal the perovskite and photovoltaic performance. Such shuttling of mobile ions without consumption in the ITO‐contact PVSCs results in harvesting–rest–recovery cycles in natural day/night operation. It is envisioned that the mechanism of the intrinsic perovskite material degradation reported here will lead to clearer research directions toward highly stable PVSCs.
Increasing Antibacterial Efficiency of Cu Surfaces by targeted Surface Functionalization via Ultrashort Pulsed Direct Laser Interference Patterning
Authors: Müller Daniel W. , Lößlein Sarah , Terriac Emmanuel , Brix Kristina , Siems Katharina , Moeller Ralf , Kautenburger Ralf , Mücklich Frank
Published: December 2020

Copper (Cu) exhibits great potential for application in the design of antimicrobial contact surfaces aiming to reduce pathogenic contamination in public areas as well as clinically critical environments. However, current application perspectives rely purely on the toxic effect of emitted Cu ions, without considering influences on the interaction of pathogenic microorganisms with the surface to enhance antimicrobial efficiency. In this study, it is investigated on how antibacterial properties of Cu surfaces against Escherichia coli can be increased by tailored functionalization of the substrate surface by means of ultrashort pulsed direct laser interference patterning (USP‐DLIP). Surface patterns in the scale range of single bacteria cells are fabricated to purposefully increase bacteria/surface contact area, while parallel modification of the surface chemistry allows to involve the aspect of surface wettability into bacterial attachment and the resulting antibacterial effectivity. The results exhibit a delicate interplay between bacterial adhesion and the expression of antibacterial properties, where a reduction of bacterial cell viability of up to 15‐fold can be achieved for E. coli on USP‐DLIP surfaces in comparison to smooth Cu surfaces. Thereby, it can be shown how the antimicrobial properties of copper surfaces can be additionally enhanced by targeted surface functionalization.