Rayleigh Scattering for An Electromagnetic Anisotropic Medium Sphere

Based on the scales theory of electromagnetic waves, the analytical expression of electrical fields inside an anisotropic medium sphere is studied. Differential scattering cross section and radar cross section （RCS） for an anisotropic spherical target are presented. The correctness of the obtained results is tested. The simulation results show that the scattering of an anisotropic sphere has the property of a dipole radiation under the condition of Rayleigh scattering. The larger the dielectric constant is, the stronger the dipole scattering is. Anisotropy in magnetism only has an effect on differential RCS. These results provide a theoretical base for the identification of anisotropic targets.     

Nonperturbative, Unitary Quantum-Particle Scattering Amplitudes from Three-Particle Equations

We here use our nonperturbative, cluster decomposable relativistic scattering formalism to calculate photon–spinor scattering, including the related particle–antiparticle annihilation amplitude. We start from a three-body system in which the unitary pair interactions contain the kinematic possibility of single quantum exchange and the symmetry properties needed to identify and substitute antiparticles for particles. We extract from it a unitary two-particle amplitude for quantum–particle scattering. We verify that we have done this correctly by showing that our calculated photon–spinor amplitude reduces in the weak coupling limit to the usual lowest order, manifestly covariant (QED) result with the correct normalization. That we are able to successfully do this directly demonstrates that renormalizability need not be a fundamental requirement for all physically viable models.     

Invariant Spinors and their Use for Expansions of Scattering Amplitudes

A general covariant scheme is proposed for the kinematical analysis of arbitrary reactions. By this scheme the problem of finding invariant amplitudes and corresponding kinematical covariants can be solved systematically. The amplitudes are labelled by two invariant indices for each particle related to spin and parity. The method provides a tool for exploiting the symmetries of the M-function, including crossing symmetry and the Pauli principle. Amplitudes free from kinematical singularities can easily be constructed.     

Resonance Rayleigh Scattering,Second-Order Scattering and Frequency Doubling Scattering Spectra of Copper(II)-Flutamide System with Anionic Surfactants and its Analytical Application

A simple, sensitive, and rapid method based on ion association, for the determination of FLD has been developed. Flutamide (FLD) can react with Cu(II) to form 1:1 cationic chelate at pH 2.2–7.0 Mclivaine buffer medium, which can further react with anionic surfactants (AS) such as sodium dodecyl sulfate (SDS), sodium lauryl sulfonate (SLS) and sodium dodecylbenzene sulfonate (SDBS) to form 1:1 ion-association complexes. As a result, the resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced to the highest degree. The maximum RRS, SOS and FDS wavelengths of three ion-association complexes were located at 345/345 nm, 610/305 nm and 430/860 nm, respectively. The increments of scattering intensity (ΔI) were directly proportional to the concentration of FLD in certain ranges. The detection limits (3σ) of FLD for SDS, SLS and SDBS systems were 1.9 ng ml⁻¹, 2.1 ng ml⁻¹ and 2.2 ng ml⁻¹(RRS method), 2.4 ng ml⁻¹, 2.7 ng ml⁻¹ and 2.6 ng ml⁻¹ (SOS method) and 2.3 ng ml⁻¹, 2.4 ng ml⁻¹ and 2.5 ng ml⁻¹ (FDS method), separately. The sensitivity of RRS method was higher than those of FDS and SOS methods. The optimum conditions of RRS method and the influence factors, the composition and the reaction mechanism have been discussed. Since the method is highly selective, it does not interference concomitant substances. These methods were applied successfully for the determination of FLD in pharmaceutical formulation and urine samples.     

The Vanishing of Two-Point Functions for Three-Loop Superstring Scattering Amplitudes

In this paper we show that the two-point function for the three-loop chiral superstring measure ansatz proposed by Cacciatori, Dalla Piazza, and van Geemen [2] vanishes. Our proof uses the reformulation of the ansatz given in [8], theta functions, and specifically the theory of the Γ₀₀ linear system, introduced by van Geemen and van der Geer [6], on Jacobians. At the two-loop level, where the amplitudes were computed by D’Hoker and Phong [11–14, 17, 18], we give a new proof of the vanishing of the two-point function (which was proven by them). We also discuss the possible approaches to proving the vanishing of the two-point function for the proposed ansatz in higher genera [3, 8, 25].     

介质球的各向异性瑞利散射

基于电磁场的多尺度理论,研究了各向异性介质球内、外电场的规律,导出了各向异性目标散射场的表达式,得到了各向异性介质目标散射振幅、散射截面等的解析表达式,并对其正确性进行了检验.仿真结果表明:各向异性介质球的散射具有偶极辐射的特点,介电常量越大,产生的偶极矩也愈大,散射也越强.其结果可为各向异性目标监测、各向异性光散射研究等提供理论支持.     

Improvement of Multichannel Amplitudes for the Pion-Pion Scattering Using the Dispersion Relations

The multichannel S- and P-wave amplitudes for the ππ scattering, constructed requiring analyticity and unitarity of the S-matrix and using the uniformization procedure, are elaborated using the dispersion relations with imposed crossing symmetry condition. The amplitudes are modified in the low-energy region to improve their consistency with experimental data and the dispersion relations. Agreement with data is achieved for both amplitudes from the threshold up to 1.8 GeV and with dispersion relations up to 1.1 GeV. Consequences of the applied modifications, e.g. changes of the S-wave lowest-pole positions, are presented.     

瑞利多普勒测风激光雷达的频率标定方法

频率标定是瑞利测风激光雷达的关键技术。瑞利测风激光雷达中,通过改变压电陶瓷管的电压实现连续调谐F-P标准具腔长,使出射激光频率处于双边缘透过率曲线的交点处。在连续调谐时,由于压电陶瓷管的磁滞效应引起腔长调谐非线性,从而导致系统误差。分析了该误差的原因及特性,提出了静态软件补偿和动态调频跟踪相结合的频率标定方法。若激光出射频率相对F-P标准具漂移小于100 MHz时,在数据反演时补偿该频率偏差;若相对频率漂移大于100 MHz时,将F-P标准具先退回预设腔长以下,通过逐步增加电压的方式,重新实现频率锁定,保证锁定过程处在磁滞回线的电压上升段,避免了磁滞效应引起的误差。多普勒激光雷达与无线电探空仪的两组对比实验中,在15～30 km高度,风速最大偏差6.22 m/s,平均偏差1.12 m/s。     

瑞利多普勒测风激光雷达的频率标定方法

频率标定是瑞利测风激光雷达的关键技术。瑞利测风激光雷达中,通过改变压电陶瓷管的电压实现连续调谐F-P标准具腔长,使出射激光频率处于双边缘透过率曲线的交点处。在连续调谐时,由于压电陶瓷管的磁滞效应引起腔长调谐非线性,从而导致系统误差。分析了该误差的原因及特性,提出了静态软件补偿和动态调频跟踪相结合的频率标定方法。若激光出射频率相对F-P标准具漂移小于100 MHz时,在数据反演时补偿该频率偏差;若相对频率漂移大于100 MHz时,将F-P标准具先退回预设腔长以下,通过逐步增加电压的方式,重新实现频率锁定,保证锁定过程处在磁滞回线的电压上升段,避免了磁滞效应引起的误差。多普勒激光雷达与无线电探空仪的两组对比实验中,在15~30km高度,风速最大偏差6.22m/s,平均偏差1.12m/s。     

海洋水色及水温扫描仪精确瑞利散射计算

瑞利散射计算精度对海洋水色遥感大气校正的精度起着关键作用,为了提高瑞利散射的计算精度,需要求解平行分层大气矢量辐射传输方程。详细地推导了加倍法解大气矢量辐射传输方程的基本关系式,并阐述了利用加倍法解矢量辐射传输方程的原理。通过与海视宽视场遥感器(SeaWiFS)精确瑞利散射查找表计算结果的比较,证明利用加倍法计算瑞利散射的精度优于0．5％,完全能够满足海洋水色遥感大气校正对瑞利散射计算精度的要求,并可以用来生成海洋水色及水温扫描仪精确瑞利散射查找表。最后,利用开发的加倍法解矢量辐射传输方程软件包,生成了海洋水色及水温扫描仪的精确瑞利散射查找表。开发的加倍法解矢量辐射传输方程软件包可直接用于我国第二代高性能海洋水色遥感器精确瑞利散射查找表的生成。     

Scattering Amplitudes Interpolating Between Instant Form and Front Form of Relativistic Dynamics

Among the three forms of relativistic Hamiltonian dynamics proposed by Dirac in 1949, the front form has the largest number of kinematic generators. This distinction provides useful consequences in the analysis of physical observables in hadron physics. Using the method of interpolation between the instant form and the front form, we introduce the interpolating scattering amplitude that links the corresponding time-ordered amplitudes between the two forms of dynamics and provide the physical meaning of the kinematic transformations as they allow the invariance of each individual time-ordered amplitude for an arbitrary interpolation angle. We discuss the rationale for using front form dynamics, nowadays known as light-front dynamics (LFD), and present a few explicit examples of hadron phenomenology that LFD uniquely can offer from first-principles quantum chromodynamics. In particular, model-independent constraints are provided for the analyses of deuteron form factors and the N Δ transition form factors at large momentum transfer squared Q ². The swap of helicity amplitudes between the collinear and non-collinear kinematics is also discussed in deeply virtual Compton scattering.     

用于噪声抑制的碘分子滤波瑞利散射技术研究

为了解决激光瑞利散射技术诊断燃烧场时存在的米散射和背景杂散光干扰问题,发展了基于碘分子超精细吸收凹陷的滤波技术。介绍了分子滤波的原理和碘分子的吸收光谱,设计了用于产生稳定数密度的碘分子滤波器,并采用种子注入、可调谐Nd：YAG激光器测量了碘分子的吸收谱。采用碘分子滤波器,在稳态燃烧场和瞬态燃烧场上分别进行了结构诊断的滤波瑞利散射实验,获得了清晰的燃烧场结构图像。实验表明碘分子滤波器能够有效抑制532nm激光瑞利散射实验中的米散射和背景杂散光,提高信号图像的清晰度。     

Rayleigh Scattering Experiment for the Measurement of Hydrogen Cluster Size

The hydrogen clusters are produced at liquid nitrogen temperature in a supersonic adiabatic expansion of moderate backing pressure gases into vacuum through a Laval nozzle and their averaged size are measured by Rayleigh scattering. The average cluster size N^-c is about 250 hydrogen atoms at a backing pressure 1.0 MPa in these measurements.     

Gravitation, the Quantum and Bohr's Correspondence Principle

The black hole combines in some sense both thehydrogen atom and the black-bodyradiation problems of quantum gravity. Thisanalogy suggests that black-hole quantization may be thekey to a quantum theory of gravity. During the last twenty-fiveyears evidence has been mounting that black-hole surfacearea is indeed quantized, with uniformally spaced areaeigenvalues. There is, however, no general agreement on the spacing of the levels. In thisessay we use Bohr's correspondence principle to providethis missing link. We conclude that the fundamental areaunit is 4h ln 3. This is the unique spacing consistent both with the area-entropythermodynamic relation for black holes, withBoltzmann-Einstein formula in statistical physics andwith Bohr's correspondence principle.     

Review of AdS/CFT Integrability,Chapter V.3: Scattering Amplitudes at Strong Coupling

Letters in Mathematical Physics - We review the computation of scattering amplitudes of planar maximally super-symmetric Yang–Mills at strong coupling. By using the AdS/CFT duality the...     

氢化物发生-催化共振瑞利散射光谱法测定痕量砷

在硫酸介质中,以硼氢化钠(NaBH₄)为还原剂,可将As(Ⅲ)还原为砷化氢(AsH₃)气体使其逸出,用Ce(SO₄)₂-H₂SO₄-KI混合液做吸收液,在催化剂KI存在下四价铈与AsH₃气体反应生成具有共振瑞利散射(RRS)的砷微粒和具有荧光的三价铈,导致体系在370 nm处的RRS信号和在351 nm处的荧光强度增大。在选定条件下,As(Ⅲ)浓度分别在0.006～0.76 mg·L-1和0.006～0.28 mg·L-1范围内与RRS增加值ΔI和荧光强度增大值ΔF₃₅₁呈线性关系,检出限均为3.0 μg·L-1。据此可建立新的检测As(Ⅲ)的催化RRS和荧光光谱法。     

C波段球体目标系的瑞利复合散射特性

在C波段研究了一对介质球体目标的瑞利复合电磁散射特性, 得到了目标复合散射截面解析式, 验证了所得结果的正确性; 研究了入射波极化状态、目标距离、目标大小、介电常数等因素对复合散射截面的影响, 结果表明, 邻近目标对本目标散射的影响具有偶极辐射的特点, 主目标的复合散射截面是邻近目标的大小、介电常数及其位置等因素的函数; 结果为目标散射截面的准确测量、电磁相互作用等奠定了理论基础。     

Review of AdS/CFT Integrability,Chapter V.1: Scattering Amplitudes: A Brief Introduction

Letters in Mathematical Physics - We review current efficient techniques for the construction of multi-leg and multi-loop on-shell scattering amplitudes in supersymmetric gauge theories. Examples...     

An Efficient Algorithm for Truncating Spatial Domain in Modeling Light Scattering by Finite-Difference Technique

The finite-difference time domain technique is one of the most robust and accurate numerical methods for the solution of light scattering by small particles with arbitrary composition and geometry. In practice, this method requires that the spatial domain for the computation of near-field be truncated. An absorbing boundary condition must be imposed in conjunction with this truncation. The performance of this boundary condition is essential to the stability of numerical computations and the reliability of results. In the present study, a new boundary condition, referred to as the mixed T algorithm, has been developed, which is a generalization of the transmitting boundary condition originally developed by Liao and co-workers. The present algorithm does not require spatial interpolation for wave values at interior grid points. In addition, it produces two minima of spurious reflections at small and large incident angles, allowing efficient absorption of the scattered waves at the boundary for large incident angles. When the third-order mixed T algorithm is used, the reflection coefficient of the boundary is less than 1% for incident angles from 0° to about 70°. We find that the numerical instability associated with the transmitting boundary condition is caused by the location-dependent amplitude of outgoing waves in the vicinity of the boundary. For this reason, the mixed T algorithm is stabilized by consistently introducing diffusive coefficients into the boundary equation. When the stabilized algorithm is applied, the near-field within the truncated domain can be computed by using single-precision arithmetic without overflows for more than 10⁵steps in the time-marching iteration. Finally, the new absorbing boundary condition is validated by carrying out numerical experiments involving the propagation of a TM wave excited by a sinusoidal point source, simultaneous simulation of the wave propagation in small and large domains, and the scattering of a TM wave by an infinite circular cylinder.     

Light Scattering and Visibility Condition of Spatial Objects

Considering background radiation of different wave band at different typical time by using Modtran soft, the characteristic of light scattering and the visibility condition of spatial object are discussed. Using bi-directional reflectance distribution function, combining geometry modeling with orbit theory, we numerical calculate light scattering radiation of spatial objects and compare it with the background radiation. The best observation time and station can be obtained by analyzing the conditions of visibility.