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Surface characteristics of rapidly solidified nickel-based superalloy pow-ders prepared by PREP

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Rare Metals 2003年第4期22卷 309-314页

作者： CHEN Huanming , HU Benfu , and LI Huiying1) school of Materials Science and engineering, university of Science and Technology Beijing, Beijing 100083, china2) school of physics and electrical information engineering, ningxia university, yinchuan 750021, china school of Materials Science and engineering University of Science and Technology Beijing Beijing 100083 Chins

The surface microstructure and the surface segregation of FGH 95 nickel-basedsuperalloy powders prepared through plasma rotating electrode processing (PREP) have beeninvestigated by using SEM and AES. The results indicate that the surface microstructure of powderschanges from dendrite into cellular stricture as the particle size of powders decrease, and thepredominant precipitates solidified on the particle surfaces were identified as MC' type carbidesenriched with Nb and Ti. It was also indicated that along with the depth of particle surfaces, thesegregation layer of S, C and O elements are thick, and that of Ti, Cr elements are thin for largesire powders while they are in reverse for median size particles.

关键词： FGH 95 nickel-based superalloy powders surface characteristics microstructure plasma rotating electrode processing

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狄拉克方程的新一类解

陕西师范大学学报（自然科学版） 2001年第4期29卷 54-59页

作者：海国廷宁夏大学物理与电气信息工程系宁夏银川750021

研究了位于由两对双曲柱面构成的波导管电磁场里的单电子的性质 ,得到了单电子在场中狄拉克方程的新一类精确解 ;计算了极化算符的本征函数 .结果表明 ,自旋系数可用恒定极化算符的本征值确定 .

关键词：单电子双曲柱面波导管狄拉克方程新一类解量子电动力学极化算符自旋系数

Balmer-alpha and Balmer-beta Stark line intensity profiles for high-power hydrogen inductively coupled plasmas

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Chinese physics B 2014年第7期23卷 499-504页

作者：王松柏雷光玖刘东平杨思泽 school of physics and Mechanical&electrical engineering Xiamen University College of physics and information engineering Fuzhou University Southwestern Institute of physics school of physics and Mechanical & electrical engineering Xiamen University

We compare Balmer-alpha （Ha） and Balmer-beta （Hβ） emissions from high-power （1.0-6.0 kW） hydrogen inductively coupled plasmas （ICPs）, and propose region Ⅰ （0.0-2.0 kW）, region Ⅱ （2.0-5.0 kW）, and region Ⅲ （5.0-6.0 kW）. In region Ⅰ, both Ha emission intensity （la） and Hβ emission intensity （1β） increase with radio frequency （RF） power, which is explained by the corona model and Boltzmann＇s law, etc. However, in region II, la almost remains constant while 1β rapidly achieves its maximum value. In region Ⅲ, 1α slightly increases with RF power, while 1β decreases with RF power, which deviates significantly from the theoretical explanation for the Ha and Hβ emissions in region I. It is suggested that two strong electric fields are generated in high-power （2.0-6.0 kW） hydrogen ICPs： one is due to the external electric field of high-power RF discharge, and the other one is due to the micro electric field of the ions and electrons around the exited state hydrogen atoms in ICPs. Therefore, the strong Stark effect can play an important role in explaining the experimental results.

关键词： high-power radio frequency plasma Hα and Hβ spectral lines in hydrogen ICPs Stark effect

A 3-D Polarization Quadrature Amplitude Modulation Method and Constellation Mapping

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china Communications 2015年第10期12卷 16-26页

作者： SUN Xuehong ZHANG Haiying ZENG Zhimin GUO Caili Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication EngineeringBeijing University of Posts and Telecommunications Key Laboratory of Intelligent Sensing for Desert information School of Physics Electrical EngineeringNingxia University

As a new three-dimensional(3-D)modulation,Polarization Quadrature Amplitude Modulation(PQAM) can be regarded as the combination of Pulse amplitude modulation(PAM) and Quadrature Amplitude Modulation(QAM) *** can better improve the digital communication efficiency and reduce the Symbol error rate(SER) of the system than one-dimensional or two-dimensional modulation *** to design a feasible constellation is the most concerned problem of PQAM *** paper first studies the relationship between the SER theoretical value of PQAM and the distribution of M and N,proposes a new M,N allocation ***,a new and straightforward design method of constructing higher-level 3-D signal constellations,which can be matched with the PQAM,and the constellation can divided into three different structures according to the ary for ***,the simulation results show that:in PQAM system,the modulation scheme and the constellation mapping scheme are proposed in this paper which can effectively reduce the system SER and improve the anti-noise performance of the system.

关键词： polarization quadrature amplitude modulation minimum euclidean distance symbol error probability 3-D constellation

Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons

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Science china(physics,Mechanics & Astronomy) 2010年第4期53卷 672-679页

作者： MA Jun 1,2, TANG Jun 2 , ZHANG AiHua 3 & JIA Ya 2 1 Department of physics, Lanzhou university of Technology, Lanzhou 730050, china 2 Department of physics, Central china Normal university, Wuhan 430079, china 3 College of electrical and information engineering, Lanzhou university of Technology, Lanzhou 730050, china 1. Department of physics Lanzhou University of Technology Lanzhou 730050 China2. Department of Physics Central China Normal University Wuhan 430079 China3. College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou 730050 China

The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise.

关键词： spiral wave factor of synchronization breakup multiplicative noise robustness

计算机模拟光源的非单色性对迈克尔孙干涉条纹可见度的影响

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物理实验 2004年第4期24卷 20-23,27页

作者：张轶炳宁夏大学物理电气信息学院宁夏银川750021

通过开发的“迈克尔孙模拟实验平台”中的数值模拟和实验现象模拟 ,讨论分析了光源的非单色性对迈克尔孙干涉条纹可见度的影响 ,用直观的计算机图形将抽象的光的时间相干性理论形象化 ,从而弥补了光学实验教学中的理论欠缺和理论教学与... 详细信息

通过开发的“迈克尔孙模拟实验平台”中的数值模拟和实验现象模拟 ,讨论分析了光源的非单色性对迈克尔孙干涉条纹可见度的影响 ,用直观的计算机图形将抽象的光的时间相干性理论形象化 ,从而弥补了光学实验教学中的理论欠缺和理论教学与实验相脱节的不足 .

关键词：高等教育物理教学迈克尔孙干涉数值模拟计算机模拟可见度干涉条纹可见度分析实验教学

Tunneling conductance in graphene ferromagnet/p wave superconductor junctions

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Science china(physics,Mechanics & Astronomy) 2012年第4期Mechanics & Astronomy) .卷 649-653页

作者： LI XiaoWei 1,2*,CHEN HuaBao 1 & LIU ShuJing 1 1 school of physics and Electronic electrical engineering,Huaiyin Normal university,Huaian 223300,china 2 State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and information Technology,Chinese Academy of Sciences,Shanghai 200050,china 1. school of physics and Electronic electrical engineering Huaiyin Normal University Huaian 223300 China2. State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

Using the extended Blonder-Tinkham-Klapwijk formalism,we investigate the conductance spectra of graphene ferromagnet/p wave superconductor *** is found that the conductance spectra are affected by the p wave pairing *** ferromagnetic exchange energy in the ferromagnet can suppress Andreev retroreflection but enhance the specular Andreev reflection in graphene ferromagnet/p wave superconductor *** conductance decreases with increasing exchange energy Eh for EhEF.

关键词： graphene ferromagnet p wave superconductor tunneling conductance

Online multiple instance regression

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Chinese physics B 2013年第9期22卷 656-661页

作者：王志岗赵增顺张长水 Department of Automation Tsinghua UniversityState Key Laboratory of Intelligent Technologie and SystemsTsinghua National Laboratory for Information Science and Technology College of information and electrical engineering Shandong University of Science and Technology school of Control Science and engineering Shandong University

The multiple instance regression problem has become a hot research topic recently. There are several approaches to the multiple instance regression problem, such as Salience, Citation KNN, and MI-ClusterRegress. All of these solutions work in batch mode during the training step. However, in practice, examples usually arrive in sequence. Therefore, the training step cannot be accomplished once. In this paper, an online multiple instance regression method ＂OnlineMIR＂ is proposed. OnlineMIR can not only predict the label of a new bag, but also update the current regression model with the latest arrived bag. The experimental results show that OnlineMIR achieves good performances on both synthetic and real data sets.

关键词： mutiple instance regression online learning

First-principles study of the formation and electronic structure of a conductive filament in ZnO-based resistive random access memory

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Chinese physics B 2014年第12期23卷 412-417页

作者：赵晶董静雨任书霞张礼勇赵旭陈伟 Key Laboratory of Advanced Films of Hebei Province College of Physics Science & Information EngineeringHebei Normal University Department of physics and electrical engineering Handan College school of Material Science and engineering Shijiazhuang Tie Dao University

Oxygen vacancy plays a crucial role in resistive switching. To date, a quantitative study about the distribution of the oxygen vacancies and its effect on the resistive switching has not yet been reported. In this study, we report our first-principles calculations in Zn O-based resistive switching memory grown on a Pt substrate. We show that the oxygen vacancies prefer to be located in the Zn O（0001） plane, i.e. in the direction parallel to the film surface in the preparation process. These oxygen vacancies drift easily in the film when a voltage is applied in the SET process and prefer to form a line defect perpendicular to the film surface. An isolated oxygen vacancy makes little contribution to the conductivity of Zn O,whereas the ordering of oxygen vacancies in the direction perpendicular to the film surface leads to a dramatic enhancement of the conductivity and thus forms conductive filaments. The semiconducting characteristics of the conductive filaments are confirmed experimentally.

关键词： first-principles calculations resistive switching conductive filament oxygen-vacancy ordering