共振非线性散射技术测定盐酸普鲁卡因与β-环湖精包结常数的新方法

盐酸普鲁卡因水溶液的共振非线性散射较弱，当β环糊精加人溶液中并与盐酸 普鲁片因形成包合物时，共振非线散射强度明显增强，且随着β-环糊精的浓度增 加，体系的共振非线性散射逐渐增强，利用共振非线性散射技术研究糊精与盐酸普 鲁卡因的相互作用，并发展了一种用二级散射、二倍频散射、三倍频散射和3／2倍 频散射技术测定β-包合物包结常数的新方法，测定结果与用分光光度法、荧光法 和共振瑞利散射法测得结果一致，从而建立起测定环糊精包结常数的新方法．     

New treatment of the theory for small-angle x-ray scattering with applications to polystyrene crazes

The phenomenon of surface scattering of electromagnetic waves by single or multiple layers of films is reviewed and a special treatment for the total reflection of x rays is developed. This theory is applied to the analysis of the surface scattering observed in small-angle x-ray scattering (SAXS) studies of two-phase matter in polymers having lamella stacks or a flat interfacial boundary structure. Important features of this vector theory are the ability to calculate the surface scattering invariant, the absolute scattering intensity, and the surface roughness, which gives rise to dispersion of specular reflection from perfectly smooth surfaces. By considering the interfacial surface roughness of polystyrene crazes, the surface scattering spectrum is calculated theoretically and compared with some experimental results. Also the theory is presented in such a way as to compare surface scattering with volume scattering; i.e., both two- and three-dimensional scattering events can be simultaneously treated. This provides a new basis for quantitative analysis of crazes in polystyrene.     

Multiple scattering of light from polymer dispersed liquid crystal material

Light scattering from polymer dispersed liquid crystal (PDLC) material has been studied experimentally and by Monte Carlo simulation. Light scattering was measured as a function of both scattering angle and cell thickness. The cell thicknesses of practical interest are in an intermediate regime where neither single scattering nor light diffusion applies. Both the angular and the thickness dependence of the scattering intensity can be described accurately by a Monte Carlo simulation of multiple scattering from a homogeneous distribution of independent scatterers. The model smoothly interpolates between the single scattering limit for thin cells and the diffusion limit for thick cells. It can easily be extended to include any specific feature of a scattering display system.     

Small-angle neutron scattering from a hexagonal phase under shear

Summary The shear orientation of a micellar hexagonal liquid crystalline phase was investigated by small-angle neutron scattering. The hexagonal phase in the quiescent state showed a symmetrical scattering pattern typical of a polydomain structure. Enhanced scattering along the flow direction was observed during shear and the anisotropy of scattering intensity became stronger with increasing shear rate. The anisotropic scattering pattern corresponds to an orientation perpendicular to the flow direction and can be interpreted as a log-rolling state. The oriented sample did not relax after cessation of shear. The results from small-angle neutron scattering confirm data obtained previously from rheo-small angle light scattering measurements and are discussed in comparison to shear alignment of lyotropic liquid crystalline polymer solutions.     

Plane wave packet formulation of atom-plus-diatom quantum reactive scattering

We recently interpreted several reactive scattering experiments using a plane wave packet (PWP) formulation of quantum scattering theory [see, e.g., S. C. Althorpe, F. Fernandez-Alonso, B. D. Bean, J. D. Ayers, A. E. Pomerantz, R. N. Zare, and E. Wrede, Nature (London) 416, 67 (2002)]. This paper presents the first derivation of this formulation for atom-plus-diatom reactive scattering, and explains its relation to conventional time-independent reactive scattering. We generalize recent results for spherical-particle scattering [S. C. Althorpe, Phys. Rev. A 69, 042702 (2004)] to atom-rigid-rotor scattering in the space-fixed frame, atom-rigid-rotor scattering in the body-fixed frame, and finally A+BC rearrangement scattering. The reactive scattering is initiated by a plane wave packet, describing the A+BC reagents in center-of-mass scattering coordinates, and is detected by projecting onto a series of AC+B (or AB+C) plane wave "probe" packets. The plane wave packets are localized at the closest distance from the scattering center at which the interaction potential can be neglected. The time evolution of the initial plane wave packet provides a clear visualization of the scattering into space of the reaction products. The projection onto the probe packets yields the time-independent, state-to-state scattering amplitude, and hence the differential cross section. We explain how best to implement the PWP approach in a numerical computation, and illustrate this with a detailed application to the H+D2 reaction.     

Small-angle light scattering from thin polymer films: Multiple scattering from samples with rodlike morphology

Hartel's theory for multiple scattering has been generalized to the case of small-angle light scattering (SALS) by polymers having a roadlike morphology. It is shown that multiple scattering tends to make the scattering tends to make the scattering patterns more diffuse and leads to an underestimation of the size of the units (rods) measured from such patterns. The error induced by neglecting multiple scattering has been estimated at 10% for a transmittance of 75% and at 22% for a transmittance of 50%. A correction method based on Hartel's procedure is suggested.     

Small-angle light scattering from thin polymer films: Multiple scattering from Debye–Bueche scatterers

An extension of Hartel's theory for multiple scattering has been applied to the case of small-angle light scattering from polymer films with random two-phase morphology. The scattering is treated in terms of Debye–Bueche theory from which values of the correlation length, an average phase size, and mean-square fluctuation in polarizability are determined. It is shown that multiple scattering leads to a reduction in the angular dependence of scattering due to an enhancement of scattering at high angles. This leads to an underestimate of the correlation length and an overestimate of the magnitude of the mean-square polarizability fluctuation.     

Time-resolved simultaneous polarized and depolarized light scattering system with high sensitivity to optical anisotropy: application to phase separation of an optically isotropic liquid mixture

Depolarized light scattering is widely used to probe the spatial correlation of optical anisotropy in crystals, liquid crystals, and viscoelastic materials under stress, and a powerful means to study a non-equilibrium pattern evolution process of such a system. To follow the temporal change in the diagonal and off-diagonal contributions of the dielectric tensor, it is highly desirable to measure two-dimensional (2D) polarized (HH: horizontally transmitted, horizontally received) and depolarized (VH: vertically transmitted, horizontally received) scattering patterns simultaneously in a time-resolved manner. We develop a light scattering system with a video-rate time resolution as well as very high sensitivity to optical anisotropy. To detect extremely weak VH scattering from a sample without suffering from residual birefringence of the optical system itself and leakage of strong HH scattering signals, we use an objective lens specially designed for polarizing microscopy and Glan-laser prisms, respectively. This system enables us to experimentally elucidate the origin of VH scattering: we use the ratio of the VH and HH scattering intensity as a fingerprint for whether a 2D VH scattering pattern is caused by (i) optical anisotropy (intrinsic birefringence) or merely by (ii) spatial inhomogeneity of optically isotropic materials. We verify the validity of this method for a process of phase separation in a binary mixture of isotropic liquids. The simultaneous HH and VH measurement allows us to directly estimate the ratio of VH and HH scattering intensity accurately. The careful comparison of this ratio with a simple theory unambiguously demonstrates that the 2D VH scattering pattern is caused by the scattering angle dependence of the diffraction efficiency of light with the two polarization directions. That is, the origin of VH scattering is due to geometrical effects of the inhomogeneous distribution of the refractive index and not due to optical birefringence, as it should be for the optically isotropic sample. This method using the ratio of VH and HH scattering intensity may be widely used for distinguishing the two types of origins for a VH scattering pattern in an unambiguous manner.     

On the determination of absolute vibrational excitation probabilities in molecule-surface scattering: Case study of NO on Au(111)

We describe a method to obtain absolute vibrational excitation probabilities of molecules scattering from a surface based on measurements of the rotational state, scattering angle, and temporal distributions of the scattered molecules and apply this method to the vibrational excitation of NO scattering from Au(111). We report the absolute excitation probabilities to the v = 1 and v = 2 vibrational states, rotational excitation distributions, and final scattering angle distributions for a wide range of incidence energies and surface temperatures. In addition to demonstrating the methodology for obtaining absolute scattering probabilities, these results provide an excellent benchmark for theoretical calculations of molecule-surface scattering.     

Scattering of light from thin polymer films. I. Multiple scattering

A general method is described to take into account the multiple scattering effect in a small-angle light scattering from thin polymer films. It is seen that multiple scattering tends to make the scattering envelope more diffuse, reducing the intensity in the high intensity regions and increasing it in the low intensity regions. The method is applied here to a spherulitic system, but it is valid for any other system where the principal scattering is in the forward direction.     

Inelastic scattering of X-rays and gamma rays

Recent progress in the following topics will be outlined. Needs and opportunities for further work will also be indicated. The topics are as follows. Compton scattering by inner shell (K and L) electrons; non-resonant Raman and Compton scattering and spin-dependent Compton scattering; atomic single-differential scattering cross-sections and incoherent scattering function (ISF) approximation; resonant Raman–Compton scattering and resonant inelastic X-ray scattering (RIXS) with possible coherence effects; ultra-high-resolution studies.     

Advantages of time-resolved difference X-ray solution scattering curves in analyzing solute molecular structure

Time-resolved X-ray solution scattering provides a powerful method for investigating reaction dynamics in the solution phase. Since X-rays scatter from all atoms in the solution sample, the scattering intensity is contributed from not only the solute but also the solvent and the solute–solvent cross terms. For a typical concentration the solvent molecules outnumber the solute molecules and thus the relative sensitivity of the scattering intensity to the solute structure is extremely low. To increase the structural sensitivity to the solute and to extract only the signal from structural changes, time-resolved difference scattering signal is obtained by subtracting the original raw scattering curve at a negative reference time delay from that at a positive time delay. Here we show and emphasize that time-resolved difference X-ray scattering curves generally exhibit higher structural sensitivity to the solute molecular structure and lower influence from experimental background and imperfection of theory than original raw scattering curves. These characteristics justify the validity of fitting models to difference curves to obtain transient structural information even when the magnitude of the time-resolved difference curves is smaller than the discrepancy between the theory and experiment for the original scattering curve. We considered small molecules and proteins in solution probed by time-resolved X-ray solution scattering.     

SAXS and SANS studies of polymer colloids

The analysis of latex particles by small-angle scattering (small-angle X-ray scattering, SAXS; small-angle neutron scattering, SANS) is reviewed. Small-angle scattering techniques give information on the radial structure of the particles as well as on their spatial correlation. Recent progress in instrumentation allows to extend SANS and SAXS to the q-range of light scattering. Moreover, contrast variation employed in SANS and SAXS studies may lead to an unambiguous determination of the radial scattering length density of the particles in situ, i.e. in suspension. Hence, these techniques are highly valuable for a comprehensive analysis of polymer colloids as shown by the examples discussed herein.     

柑桔溃疡菌的共振散射光谱

研究了柑桔溃疡菌的共振散射光谱,在330、425、465和695 nm产生四个共振散射峰.当激发波长为330 nm （9.09×1014 Hz）时,溃疡菌溶液在330 nm（9.09×1014 Hz）、660 nm（1/2×9.09×1014 Hz）和990 nm（1/3×9.09×1014 Hz）分别产生一共振散射峰和1/2、1/3两个分频散射峰;当激发波长为465 nm（6.45×1014 Hz）时,在456 nm(6.45×1014 Hz)和930 nm(1/2×6.45×1014 Hz)分别产生一个共振散射峰和一个1/2分频射峰; 当激发波长为930 nm(3.23×1014 Hz)时,在930 nm (3.23×1014 Hz)、620 nm(3/2×3.23×1014 Hz)、465 nm(2×3.23×1014 Hz) 和310 nm (3×3.23×1014 Hz)分别产生一个共振散射峰,一个3/2分频共振散射峰,一个2倍频共振散射峰和一个3倍频共振散射峰.柑桔溃疡菌是一种非线性散射光学介质.分频散射和倍频散射峰与共振散射峰具有相似的散射行为.     

A new approach in small-angle neutron scattering: A method of triple isotopic substitutions

A new method is proposed for studying the structure and mutual arrangement of selected components in multicomponent particles. Here the difference between the scattering curve of a solution containing two types of structurally identical particles (differing only in the degree of deuteration) and the scattering curve of a solution containing particles of a third type (deuterated to an intermediate degree) is considered. This difference scattering curve differs only by a numerical multiplier from the “vacuum” scattering curve of the particle in which the scattering density is equal to the difference between the scattering densities of the particles of the first and second types. This means that any particle component which is deuterated (protonated) to the same degree in the particles of three different types does not contribute to the difference scattering curve and, consequently, is “invisible” for neutrons. The difference scattering curve depends neither on the isotopic content of the solvent nor on the inter-particle interference and particle association. Possible applications of this method are discussed.     

Variable-Angle Synchronous Luminescence Spectroscopy for Elimination of Second-Order Scattering Light

Various kinds of scattering light should be eliminated in fluorescence and phosphorescence analysis. Constant-wavelength and constant-energy synchronous scanning have the advantages of reducing first-order scattering lights. When excitation wavelength is far from emission wavelength, one should pay attention to second-order scattering light. We found second-order scattering light can be suppressed by using variable-angle synchronous luminescence spectroscopy (VASLS). In this paper, the principle and method of eliminating second-order scattering light will be presented.     

Effect of disorder in the twist angle on light scattering by a three-dimensional spherulite

Light scattering patterns are calculated for imperfect three-dimensional spherulites with fluctuations in the twist angle. The fluctuations are described in terms of a parameter characterizing the distance correlation function. Cases are considered in which (i) the principal axis of the scattering element makes a constant angle with the radius but there is disorder in the twist angle about the axis, and (ii) there is combined twist disorder and orientation disorder of the scattering elements. Calculations suggest that the disorder in the twist angle may lead to a decrease in the higher-order variation of scattered intensity with scattering angle and deviation from the four-leaf-clover-type scattering characteristic of a perfect spherulite at lower scattering angles. On the other hand, disorder in orientation has little effect on the scattering pattern.     

Volterra inverse scattering series method for one‐dimensional quantum barrier scattering

The Volterra inverse scattering series method is developed to obtain the interaction potential for one‐dimensional quantum barrier scattering problems. The Lippmann–Schwinger equation describing quantum barrier scattering is renormalized from a Fredholm to a Volterra integral equation. Employing the Born–Neumann series solution of the Lippmann–Schwinger Volterra equation and a related expansion of the interaction potential in orders of the data, we derive the Volterra inverse scattering series for the reflection and transmission amplitudes. Each term of the interaction potential is computed using the scattering amplitude and the Volterra Green's function. We do not consider the separate issue of extracting scattering amplitudes from quantum cross sections. The triangular nature of the Volterra Green's function significantly reduces computational effort. The Volterra series is then applied to several one‐dimensional quantum barrier scattering problems. Computational results show that the first few terms in the Volterra series can yield accurate interaction barriers. In addition, the potential barriers are calculated using the Born inverse scattering series based on the Lippmann–Schwinger Fredholm equation with the reflection amplitude. The comparison between the Born and Volterra results demonstrates that the Volterra inverse scattering series can provide a more accurate and more efficient method for determining the interaction potential.     

Atom-molecule scattering with the average wavefunction method

The average wavefunction method (AWM) is applied to atom-molecule scattering. In its simplest form the labor involved in solving the AWM equations is equivalent to that involved for elastic scattering in the same formulation. As an initial illustration, explicit expressions for the T-matrix are derived for the scattering of an atom and a rigid rotor. Results are presented for low-energy scattering and corrections to the Born approximation are clearly evident. In general, the AWM is particularly suited to polyatom scattering due to its reduction of the potential in terms of a separable atom-atom potential.