共查询到20条相似文献,搜索用时 109 毫秒
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考察了经典波动理论中的相位不变性,并且提出它作为物理学基本原理的直观依据———物理量的序列不变性.序列不变性是相对论原理的一个反映.从相位不变性出发,在给定时空变换关系下(伽利略变换和洛伦兹变换),得到波矢、频率和描述波包(类似于经典粒子)运动的群速度的坐标变换公式.另外,讨论了薛定谔方程、克莱因-戈尔登方程的相位坐标变换问题.对于薛定谔方程,我们认为量子力学中的复概率幅解放了经典波动情形下(波函数的实部具有独立物理意义)必须满足的相位不变性的约束,从而扩展了物理学的疆域,使它成为非相对论量子力学的基础;对于克莱因-戈尔登方程,它的解满足相位不变性,虽然对复波函数一般很难定义物理量序列的概念,但是对于克莱因-戈尔登方程,我们认为它也隐藏了某种序列不变性,并且结合倪光炯教授的双组分(正反粒子成分)观念给出了定义这种序列的一种可能性. 相似文献
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拟可积Hamilton系统随机平均法可以用来研究活性布朗粒子运动.介绍了该随机平均法,利用它详细求解了布朗粒子运动的动力学方程,该方程描述了活性布朗粒子在平面上的运动,粒子受到的激励是Gaussian白噪声,受到的阻尼是Schienbein-Gruler速度依赖的磨擦模型.通过与数字模拟和与实验数据的比较,证明所得稳态解正确.对于Rayleigh和Erdamnn速度依赖的磨擦模型,也给出了稳态解.
关键词:
活性布朗粒子
拟可积Hamilton系统随机平均法
可积性
稳态解 相似文献
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根据尖峰孤子解的特点,提出了一种待定系数法求非线性波方程尖峰孤子解的思路和方法,并利用该方法求解了5个非线性波方程,即CH(Camassa-Holm)方程、五阶KdV-like 方程、广义Ostrovsky方程、组合KdV-mKdV方程和Klein-Gordon方程,比较简便地得到了这些方程的尖峰孤子解.文献中关于CH方程的结果成为本文结果的特例.通过数值模拟给出了部分解的图像.简要说明了非线性波方程存在尖峰孤子解所须满足的特定条件.该方法也适用于求其他非线性波方程的尖峰孤子解.
关键词:
非线性波方程
尖峰孤子解
待定系数法 相似文献
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使用代数方法给出了粒子质量显含时间的Dirac方程的严格解,解的结构显示了粒子的正负能态与其自旋态具有交换对称性.
关键词: 相似文献
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利用基本电子元器件和常用普通芯片设计出能产生频率可调方波、三角波、正弦波信号的电路;并制作出PCB板,制成实物供"示波器使用"实验使用,即方便了教学,又节约了经费。 相似文献
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F.G. Mitri 《Ultrasonics》2010,50(6):620-627
Objective
The present research examines the acoustic radiation force of axisymmetric waves incident upon a cylinder of circular surface immersed in a nonviscous fluid. The attempt here is to unify the various treatments of radiation force on a cylinder with arbitrary radius and provide a formulation suitable for any axisymmetric incident wave.Method and results
Analytical equations are derived for the acoustic scattering field and the axial acoustic radiation force. A general formulation for the radiation force function, which is the radiation force per unit energy density per unit cross-sectional surface, is derived. Specialized forms of the radiation force function are provided for several types of incident waves including plane progressive, plane standing, plane quasi-standing, cylindrical progressive diverging, cylindrical progressive converging and cylindrical standing and quasi-standing diverging waves (with an extension to the case of spherical standing and quasi-standing diverging waves incident upon a sphere).Significance and some potential applications
This study may be helpful essentially due to its inherent value as a canonical problem in physical acoustics. Potential applications include particle manipulation of cylindrical shaped structures in biomedicine, micro-gravity environments, fluid dynamics properties of cylindrical capillary bridges, and the micro-fabrication of new cylindrical crystals to better control light beams. 相似文献14.
M. Krawczyk 《Journal of magnetism and magnetic materials》2010,322(5):562-565
We show that magnetostatic modes with amplitude localized in different regions of the sample along the direction of the magnetic field occur in ferromagnetic stripes: bulk-dead modes, with amplitude localized in two regions and comb modes localized in its central part. We also demonstrate these localization properties can be studied by Brillouin light scattering techniques and applied in practice. Having established that the localization of these modes varies with their frequency, we use this finding as the basis of a trial reinterpretation of experimental results obtained by Demidov et al. [Appl. Phys. Lett. 92 (2008) 232503]. 相似文献
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设计并搭建了一套简易的激光衍射实验装置,通过该装置作者测量了水的表面波的波长,并确定了水的表面波主要成份是毛细成分。 相似文献
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再谈尼科耳棱镜中e光的传播 总被引:6,自引:4,他引:2
从e光波的波法线分析着手,导出确定e光波的波法线,波射线方向的表达式,论述了e光波在尼科耳棱镜内加拿大树胶层的发生全反射的条件,并给出定量结果。 相似文献
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The coupling of lower hybrid wave to the plasma is a
crucial issue for efficient current drive in tokamaks. This paper
establishes a new coupling model which assumes the antenna to be a
curved face and the plasma to be a cylinder. Power spectrum considering
the coupling between wave-guides in both poloidal and toroidal
direction is simply estimated and discussed. The effect of the poloidal wave
vector on wave propagation, power deposition and driven current is
also investigated with the help of lower hybrid current drive code.
Results show that the poloidal wave vector affects the ray tracing,
and also has effect on power deposition and driven current. The
effect of the poloidal wave vector on power deposition and driven
current profile depends on plasma parameters. Preliminary studies
suggest that it seems possible to control the current profile by
adjusting the poloidal phase difference between the waveguide in
poloidal direction. 相似文献