On Ludvig Lorenz and his 1890 treatise on light scattering by spheres

The European Physical Journal H - This paper offers background and perspective on a little-known memoir by Ludvig Lorenz on light scattering by spheres, which was published in Danish in 1890. It is...     

Numerical Study of the Kneading Theory for the Lorenz Model

To a good approximation, the Lorenz attractor in the Poincark section may be viewed as a one-dimensional object. A family of maps proposed by Sparrow models the Lorenz system very well. Such maps are numerically constructed. Under the guide of the kneading theory for the maps a numerical study of the Lorenz system is conducted.     

Non-Maxwellian shape of electron distribution function in ionacoustic turbulence

In a DC discharge plasma system, in which two meshes are installed, the current-driven ion acoustic instability is excited when a de potential V_m is applied to one of them. When the instability fully grows, the system reaches a very turbulence state, the so-called ion acoustic turbulence. The experimental measurement of energy distribution function of electrons in ion acoustic turbulence measured by the Langmuir probe shows a non-Maxwellian nature along with electron heating     

光场衍射的量子理论

用量子理论推导的平面孔衍射积分，和现有的衍射理论完全一致。光子衍射的观点可以帮助了解光的衍射本质，衰减波是不确定性原理的要求。     

汤川秀树与π介子理论的提出

日本物理学家汤川秀树(YuKawa Heidiki.1907～1981),因在1935年提出介子场理论而对核物理作出的贡献,被授予1949年度的诺贝尔物理奖,成为日本第一位诺贝尔奖获得者.汤川秀树的成功,轰动了日本,同时吸引了大批青年学生热爱物理并投入这一研究领域,为物理学在日本的发展起到了推动作用.     

Ring Light Beam Deflector: Theory

The arrayed-waveguide deflector for 3-D light beam steering is described. The proposed structure with a 2-D waveguide is suitable for using the electrooptic effect. The device can also generate a light beam with phase singularity. Its usage is expected to find many applications including measurement and information processing. When the device is used to implement an N channel large-scale optical switch, only a 3N^1/2 waveguide array is required for a phaser. Fast beam steering will lead to new field of applications impossible with conventional devices.     

共振光散射的时间量子理论

本文发展了Ｓｃｈｏｍｍｅｒｓ的时间观点，定义了时间，尤其是表征量子系统光散射的散射时间和共振散射时间。通过散射时间本征态的假定实现了散射时间的量子化，得到了量子化的共振散射时间。对原子的弹性光散射和Ｒａｍａｎ散射的成功应用推出了原子和原子的价电子逐级电离所形成的离子的所有原子能级的普适近似公式。     

Atomic Scale of an Electrical Area for Unipolar Light Pulses

JETP Letters - A new parameter of “the atomic scale of an electrical area” has been introduced. It shows the effect of unipolar pulses on a quantum system. This parameter is equal to...     

Non-Maxwellian probability density function of fibers with lumped polarization mode dispersion elements

We give an analytical expression for the probability density function of the differential group delay for a concatenation of Maxwellian fiber sections and an arbitrary number of lumped elements with constant and isotropically oriented birefringence. When the contribution of the average squared of the constant birefringence elements is a significant fraction of the total, we show that the outage probability can be significantly overestimated if the probability density function of the differential group delay is approximated by a Maxwellian distribution.     

Finite-Temperature Field Theory on the Light Front

The formulation of statistical physics using light-front quantization, instead of conventional equal-time boundary conditions, has important advantages for describing relativistic statistical systems, such as heavy ion collisions. We develop light-front field theory at finite temperature and density with special attention to quantum chromodynamics. First, we construct the most general form of the statistical operator allowed by the Poincaré algebra. In light-front quantization, the Green’s functions of a quark in a medium can be defined in terms of just two-component spinors and do not lead to doublers in the transverse directions. Since the theory is non-local along the light cone, we use causality arguments to construct a solution to the related zero-mode problem. A seminal property of light-front Green’s functions is that they are related to parton densities in coordinate space. Namely, the diagonal and off-diagonal parton distributions measured in hard scattering experiments can be interpreted as light-front density matrices.     

Detection Theory of Polydispersities by Dynamic Light Scattering

ＤｅｔｅｃｔｉｏｎＴｈｅｏｒｙｏｆＰｏｌｙｄｉｓｐｅｒｓｉｔｉｅｓｂｙＤｙｎａｍｉｃＬｉｇｈｔＳｃａｔｅｒｉｎｇＺＨＡＮＧＹｉｘｉｎＺＨＵＴｏｕＺＨＡＮＧＪｉａｎｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｃｈａｎｉｃｓ，ＷｕｘｉＵｎｉｖｅｒｓｉｔｙｏｆＬｉ...     

The Lorenz Number and the Lorenz Gauge—Known Concepts,Unknown Physicist

Ludvig Lorenz was Denmark's first theoretical physicist of international recognition. Despite his important contributions to a broad range of experimental and theoretical physics, he generally appears as a somewhat peripheral figure in histories of late‐nineteenth‐century physics and is completely overshadowed by his near‐namesake H. A. Lorentz. Herein, a selected number of Lorenz's works is introduced with an eye on those which are still of relevance to modern physics and today eponymously associated with his name. These contributions are known as the Lorenz number, the Lorenz gauge, the Lorenz–Lorentz law or formula, and the Lorenz–Mie scattering theory.     

Impulsive synchronization of Lorenz systems

We study impulsive synchronization of two Lorenz systems. In an impulsive synchronization scheme, driving signals are transmitted to the driven system at discrete instants. The driven system changes its state variables instantaneously at these discrete instants according to synchronization errors. An asymptotically stable impulsive synchronization scheme is presented. The boundaries of stable regions of impulsive synchronization are also presented. Computer simulation results are given.     

Master-slave synchronization and the Lorenz equations

Since the seminal remark by Pecora and Carroll [Phys. Rev. Lett. 64, 821 (1990)] that one can synchronize chaotic systems, the main example in the related literature has been the Lorenz equations. Yet this literature contains a mixture of true and false, and of justified and unsubstantiated claims about the synchronization properties of the Lorenz equations. In this note we clarify some of the confusion. (c) 1997 American Institute of Physics.     

广义洛伦兹磁力的定义及证明

给出了广义洛伦兹磁力的定义和证明,论证指出电场既不是动磁场直接产生的更不是变磁场产生的;先有感应电流I,后有电压Uab和电场Eab。解决了愣茨与法拉第之间的原因与结果的哲学争议问题;在当时没有发现电子的情况下,法拉第的漩涡电场及其电动势都是虚构的;完整洛伦兹磁力是电磁感应的物理本质。     

具有电流阻挡层的不同GaN基LED的光电特性(英文)

研究对比了InGaN/GaN多量子阱发光二极管中p电极下的不同SiO2电流阻挡层的光电特性。6种样品被分为3组:普通表面、表面粗化、表面粗化+边墙腐蚀。每组都有两种结构,一种具有电流阻挡层,另一种没有电流阻挡层。每组中,具有电流阻挡层的LED在20 mA下的正向电压分别为3.156,3.282,3.284 V,略高于不含电流阻挡层的样品(Vf=3.105,3.205,3.210 V).但是,具有电流阻挡层的LED的光效和光功率要优于无电流阻挡层的器件,在20 mA下的光功率分别提高了10.20%、12.19%和11.49%。这些性能的提升都要归功于电流阻挡层良好的电流扩展效应,同时电流阻挡层还可以减小p电极下的寄生光吸收。     

Lorenz number of solid and liquid gallium

The Lorenz number of solid and liquid Ga near the melting point has been carefully measured by using a modified Kohlrausch method. We obtained temperature independent values in good agreement with the free-electron Lorenz number.     

Masses and Widths of Light Scalar Mesons in Chiral Perturbation Theory

Based on the diquark model, we assume that the light scalar mesons are q^2q^-2 states rather than qq^-. The chiral effective Lagrangian for the light scalar meson is constructed, and the mass relations are obtained： the isotriplet （a0） and the isosinglet （f0） are the heaviest and are degenerate, the isodoublets （κ） are heavier and the other isosinglet （σ） is the lightest; and 2Mκ^2 = Mα0^2＋ Mσ^2. Using experimental value for a0 and σ mass, we obtain Mκ=794 MeV, which is consistent with the experimental value. Then taking Г（a0^0 →ηπ^0） = 90 MeV and Г（f0→π^0π^0） = 20 MeV, we get the width of σ is： Г（σ0→π^＋π^-）= 150 MeV.     

热光源产生贝塞尔光束的理论与实验

利用热光源获得了近似贝塞尔光束。对多波长光波同时入射轴棱锥的情形进行分析和数值模拟,结果显示轴棱锥后会形成近似贝塞尔光束,但受光场非相干叠加的影响截面光强对比度降低。实验采用卤素灯杯作为产生贝塞尔光束的热光源,针对热光源相干性差的特点设计出一套光学系统,提高光波的空间相干性,再使光波平行透过轴棱锥得到了近似贝塞尔光束。将实验结果与数值计算对比,发现实验所得贝塞尔光束的特性与理论基本吻合,但最大无衍射距离较理论计算所得的短,并对此进行了分析。