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Surface plasmon oscillations in a semi-bounded semiconductor plasma
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作者 M SHAHMANSOURI A P MISRA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第2期76-81,共6页
We study the dispersion properties of surface plasmon(SP) oscillations in a semi-bounded semiconductor plasma with the effects of the Coulomb exchange(CE) force associated with the spin polarization of electrons a... We study the dispersion properties of surface plasmon(SP) oscillations in a semi-bounded semiconductor plasma with the effects of the Coulomb exchange(CE) force associated with the spin polarization of electrons and holes as well as the effects of the Fermi degenerate pressure and the quantum Bohm potential.Starting from a quantum hydrodynamic model coupled to the Poisson equation,we derive the general dispersion relation for surface plasma waves.Previous results in this context are recovered.The dispersion properties of the surface waves are analyzed in some particular cases of interest and the relative influence of the quantum forces on these waves are also studied for a nano-sized Ga As semiconductor plasma.It is found that the CE effects significantly modify the behaviors of the SP waves.The present results are applicable to understand the propagation characteristics of surface waves in solid density plasmas. 展开更多
关键词 surface plasmon oscillations semiconductor plasma semi-bounded plasma
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Surface Wave Echo in a Semi-Bounded Plasma
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作者 Hee J. Lee Myoung-Jae Lee 《Journal of Modern Physics》 2016年第12期1400-1412,共13页
Plasma echo theory is revisited to apply it to a semi-bounded plasma. Spatial echoes associated with plasma surface wave propagating in a semi-bounded plasma are investigated by calculating the second order electric f... Plasma echo theory is revisited to apply it to a semi-bounded plasma. Spatial echoes associated with plasma surface wave propagating in a semi-bounded plasma are investigated by calculating the second order electric field produced by external charges and satisfying the boundary conditions at the interface. The boundary conditions are two-fold: the specular reflection condition and the electric boundary condition. The echo spots are determined in terms of the perpendicular coordinate to the interface and the parallel coordinate along which the wave propagates. This improves the earlier works in which only the perpendicular coordinate is determined. In contrast with the echo in an infinite medium, echoes in a bounded plasma can occur at various spots. The diversity of echo occurrence spots is due to the discontinuity of the electric field at the interface that satisfies the specular reflection boundary condition. Physically, the diversity appears to be owing to the reflections of the waves from the interface. 展开更多
关键词 Plasma Echo semi-bounded Plasma Boundary Condition
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Asymptotic Behavior of Global Classical Solutions to the Cauchy Problem on a Semi-Bounded Initial Axis for Quasilinear Hyperbolic Systems 被引量:1
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作者 Wei Wei HAN1,2 1. Department of Applied Mathematics, Donghua University, Shanghai 201620, P. R. China 2. School of Mathematical Sciences, Fudan University, Shanghai 200433, P. R. China 《Journal of Mathematical Research and Exposition》 CSCD 2010年第1期41-53,共13页
In this paper we study the asymptotic behavior of global classical solutions to the Cauchy problem with initial data given on a semi-bounded axis for quasilinear hyperbolic systems. Based on the existence result on th... In this paper we study the asymptotic behavior of global classical solutions to the Cauchy problem with initial data given on a semi-bounded axis for quasilinear hyperbolic systems. Based on the existence result on the global classical solution, we prove that, when t tends to the infinity, the solution approaches a combination of C1 travelling wave solutions with the algebraic rate (1 + t)^-u, provided that the initial data decay with the rate (1 + x)^-(l+u) (resp. (1 - x)^-(1+u)) as x tends to +∞ (resp. -∞), where u is a positive constant. 展开更多
关键词 quasilinear hyperbolic system Cauchy problem on a semi-bounded initial axis global classical solution weak linear degeneracy matching condition travelling wave.
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一类高阶有理差分方程的动力学定理
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作者 全卫贞 王丽 +4 位作者 周敬人 黄日娣 刘付滢 吴语桐 胡可满 《井冈山大学学报(自然科学版)》 2024年第4期7-12,共6页
根据差分方程理论,证明了高阶有理差分方程χ_(n+1)=A+Bχ_(n)/3的5个动力学定理,即唯一的正平衡解x的局部渐近稳定性、全局渐近稳定性、有界性、持续性、周期解与半循环长度等不同结论。并用计算机Matlab程序描绘此差分方程解的图像,... 根据差分方程理论,证明了高阶有理差分方程χ_(n+1)=A+Bχ_(n)/3的5个动力学定理,即唯一的正平衡解x的局部渐近稳定性、全局渐近稳定性、有界性、持续性、周期解与半循环长度等不同结论。并用计算机Matlab程序描绘此差分方程解的图像,进一步验证了这5个定理。 展开更多
关键词 差分方程 平衡解 渐近稳定性 有界性 半循环长度
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不确定刚性机械臂的鲁棒输出控制 被引量:6
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作者 李世敬 富彦丽 萧蕴诗 《电机与控制学报》 EI CSCD 北大核心 2006年第3期308-311,共4页
针对不确定刚性机械臂系统的鲁棒控制和抖振问题,在仅有精确关节位置反馈的情况下,通过引入速度滤波器生成伪速度信号,并利用反推补偿设计滤波增益,提出了一种基于速度估计的鲁棒输出反馈控制策略。滤波器-控制器设计中不含有开关控制项... 针对不确定刚性机械臂系统的鲁棒控制和抖振问题,在仅有精确关节位置反馈的情况下,通过引入速度滤波器生成伪速度信号,并利用反推补偿设计滤波增益,提出了一种基于速度估计的鲁棒输出反馈控制策略。滤波器-控制器设计中不含有开关控制项,有效避免了控制抖振现象。该算法对采样频率无严格限制,最终可确保系统闭环半全局一致有界收敛。通过两关节机械臂的仿真实例验证了所提算法的有效性。 展开更多
关键词 机械臂 速度滤波器 鲁棒控制 半全局一致有界收敛
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函数两种凸性定义等价性的今惑前世之初探 被引量:1
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作者 全然 《大学数学》 2021年第1期72-76,共5页
通过研究中点凸函数和一般凸函数这两种凸性定义的早期发展历史和凸性性质来探索两种凸性定义的等价性.结果表明,两种凸性定义不等价;但是,当函数满足连续、可微、半连续和有界这四个条件中的任何一个条件时,两种凸性定义等价.
关键词 两种凸性定义 连续 可微 半连续 有界 等价性
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ON GENERALIZED FEYNMAN-KAC TRANSFORMATION FOR MARKOV PROCESSES ASSOCIATED WITH SEMI-DIRICHLET FORMS
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作者 韩新方 马丽 《Acta Mathematica Scientia》 SCIE CSCD 2016年第6期1683-1698,共16页
Suppose that X is a right process which is associated with a semi-Dirichlet form (ε, D(ε)) on L2(E; m). Let J be the jumping measure of (ε, D(ε)) satisfying J(E x E- d) 〈 ∞. Let u E D(ε)b := D(... Suppose that X is a right process which is associated with a semi-Dirichlet form (ε, D(ε)) on L2(E; m). Let J be the jumping measure of (ε, D(ε)) satisfying J(E x E- d) 〈 ∞. Let u E D(ε)b := D(ε) N L(E; m), we have the following Pukushima's decomposition u(Xt)-u(X0) --- Mut + Nut. Define Pu f(x) = Ex[eNT f(Xt)]. Let Qu(f,g) = ε(f,g)+ε(u, fg) for f, g E D(ε)b. In the first part, under some assumptions we show that (Qu, D(ε)b) is lower semi-bounded if and only if there exists a constant a0 〉 0 such that /Put/2 ≤eaot for every t 〉 0. If one of these assertions holds, then (Put〉0is strongly continuous on L2(E;m). If X is equipped with a differential structure, then under some other assumptions, these conclusions remain valid without assuming J(E x E - d) 〈 ∞. Some examples are also given in this part. Let At be a local continuous additive functional with zero quadratic variation. In the second part, we get the representation of At and give two sufficient conditions for PAf(x) = Ex[eAtf(Xt)] to be strongly continuous. 展开更多
关键词 semi-Dirichlet form generalized Feynman-Kac semigroup strong continuity lower semi-bounded representation of local continuous additive functionalwith zero quadratic variation
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渐近锥几个定义的等价性和性质及其在经济学中的应用
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作者 李江峰 刘肇军 刘宗谦 《贵州师范大学学报(自然科学版)》 CAS 2008年第2期79-82,94,共5页
在Jean-Baptiste等(2004)、Tyrrell(1970)和Debreu(1959)给出不同的渐近锥定义的基础上,在附加凸性的条件下证明了这几个渐近锥定义的等价性,并利用这种等价性给出了渐近锥的几个重要性质的另外一种证明方法,最后讨论了渐近锥在经济学... 在Jean-Baptiste等(2004)、Tyrrell(1970)和Debreu(1959)给出不同的渐近锥定义的基础上,在附加凸性的条件下证明了这几个渐近锥定义的等价性,并利用这种等价性给出了渐近锥的几个重要性质的另外一种证明方法,最后讨论了渐近锥在经济学中的应用。 展开更多
关键词 凸集 渐近锥 有界性 正半无关性 生产集
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一类三阶非线性系统的全局稳定性分析
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作者 吴明录 《应用数学》 CSCD 北大核心 1993年第1期50-54,共5页
本文先利用Liapunov函数方法证明一类三阶非线性系统的渐近稳定性,然后在不同情况下利用Shimanov区域方法证明其正半轨线的有界性,最终得到了系统在一些较弱条件下的全局稳定性。
关键词 非线性系统 全局稳定性
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一类具混合功能反应函数的三种群捕食链模型分析
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作者 陈以平 张维 《湖北民族学院学报(自然科学版)》 CAS 2008年第4期364-369,共6页
提出并研究了一类具有脉冲干扰和混合功能反应的三种群捕食链模型.得到系统存在半平凡周期解.通过脉冲微分方程的Floquet理论和小幅扰动方法,研究了半平凡周期解的局部稳定性.证明了系统所有解是一致最终有界的.最后给出了数值分析实例.
关键词 捕食链模型 脉冲干扰 混合功能性反应 半平凡周期解 灭绝性 有界性
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参数集值变分不等式的解映射的有界性和连续性(英文)
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作者 范丽亚 《应用数学》 CSCD 北大核心 2007年第2期301-306,共6页
本文借助于非空闭凸集序列的外极限集和极大单调集值映射的外极限研究了参数集值变分不等式的集值解映射的有界性和外半连续性.
关键词 参数集值变分不等式 解映射 有界性 外(下)半连续性
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半狄氏型的符号光滑测度扰动 被引量:1
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作者 王玮 韩新方 马丽 《北京交通大学学报》 CAS CSCD 北大核心 2015年第6期126-130,共5页
假设(Xt,Px)是与L2(E;m)上的半狄氏型(E,D(E))相联系的右过程.μ为符号光滑测度,Aμt为μ对应的连续可加泛函.定义广义Feynman-Kac半群Pμtf(x)∶=E[e-Aμtxf(Xt)].设Eμ(f,g)=E(f,g)+(f,g)μ,f,g∈D(Eμ)=D(E)∩L2(E,|μ|),我们得到... 假设(Xt,Px)是与L2(E;m)上的半狄氏型(E,D(E))相联系的右过程.μ为符号光滑测度,Aμt为μ对应的连续可加泛函.定义广义Feynman-Kac半群Pμtf(x)∶=E[e-Aμtxf(Xt)].设Eμ(f,g)=E(f,g)+(f,g)μ,f,g∈D(Eμ)=D(E)∩L2(E,|μ|),我们得到以下两个命题等价:①(Eμ,D(Eμ))是下半有界的;②对任意的t>0,存在一个常数α0≥0使得‖Pμt‖2≤eα0t.如果①和②中有一个成立,则(Pμt)t≥0是L2(E;m)上强连续的半群. 展开更多
关键词 半狄氏型 下半有界 广义Feynman-Kac半群 强连续性
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Menger—PN空间中的一些重要定理 被引量:1
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作者 米献炜 王元夔 《河北师范大学学报(自然科学版)》 CAS 1992年第3期1-3,共3页
本文给出了Menger—PN空间中的一致有界定理、开映象定理、闭图定理以及关于半有界的一条共鸣定理。它们是Banach空间中有关定理的推广。
关键词 M—PN空间 一致有界 半有界 开映象 闭图
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Stability Analysis of a Nonlinear Difference Equation
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作者 Fatma Bozkurt 《International Journal of Modern Nonlinear Theory and Application》 2013年第1期1-6,共6页
The local and global behavior of the positive solutions of the difference equation was investigated, where the parametersα,βandγand the initial conditions are arbitrary positive numbers. Furthermore, the characteri... The local and global behavior of the positive solutions of the difference equation was investigated, where the parametersα,βandγand the initial conditions are arbitrary positive numbers. Furthermore, the characterization of the stability was studied with a basin that depends on the conditions of the coefficients. The analysis about the semi-cycle of positive solutions has end the study of this work. 展开更多
关键词 DIFFERENCE EQUATIONS STABILITY Analysis Semi-Cycle SOLUTIONS BOUNDEDNESS
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半Markov跳变系统的有限时间耗散控制
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作者 李秀英 姜囡 《东北师大学报(自然科学版)》 CAS 北大核心 2023年第4期46-51,共6页
研究了半Markov跳变系统的有限时间耗散性分析与控制问题.利用线性矩阵不等式,分析了半Markov跳变系统有限时间有界的条件,并在此基础上给出了该系统有限时间有界且严格耗散的充分条件.设计了状态反馈控制器,使闭环系统有限时间有界且... 研究了半Markov跳变系统的有限时间耗散性分析与控制问题.利用线性矩阵不等式,分析了半Markov跳变系统有限时间有界的条件,并在此基础上给出了该系统有限时间有界且严格耗散的充分条件.设计了状态反馈控制器,使闭环系统有限时间有界且严格耗散.通过数值算例验证了所提出方法的有效性. 展开更多
关键词 半Markov跳变系统 有限时间有界 严格耗散 线性矩阵不等式
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关于多元函数的半连续性的研究
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作者 赵占平 李东亚 《天中学刊》 2002年第2期4-6,共3页
给出了半连续函数的定义 ,研究了函数具有半连续性的条件 。
关键词 多元函数 半连续性 有界闭区域 充要条件 半连续函数 数学分析 有限覆盖定理
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An Equilibrium Version of Set-Valued Ekeland Variational Principle and its Applications to Set-Valued Vector Equilibrium Problems 被引量:1
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作者 Jing Hui QIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2017年第2期210-234,共25页
By using Gerstewitz functions, we establish a new equilibrium version of Ekeland varia- tional principle, which improves the related results by weakening both the lower boundedness and the lower semi-continuity of the... By using Gerstewitz functions, we establish a new equilibrium version of Ekeland varia- tional principle, which improves the related results by weakening both the lower boundedness and the lower semi-continuity of the objective bimaps. Applying the new version of Ekeland principle, we obtain some existence theorems on solutions for set-valued vector equilibrium problems, where the most used assumption on compactness of domains is weakened. In the setting of X complete metric spaces (Z, d), we present an existence result of solutions for set-valued vector equilibrium problems, which only requires that the domain X C Z is countably compact in any Hausdorff topology weaker than that induced by d. When (Z, d) is a Fechet space (i.e., a complete metrizable locally convex space), our existence result only requires that the domain C Z is weakly compact. Furthermore, in the setting of non-compact domains, we deduce several existence theorems on solutions for set-valued vector equilibrium problems, which extend and improve the related known results. 展开更多
关键词 Ekeland variational principle set-valued vector equilibrium problem quasi-ordered locally convex space lower semi-continuity lower boundedness
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