Reverse saturation absorption in PK 792 and PK 7098 dyes

The results of z-scanning in PK 792 and PK 7098 polymethine dyes are presented. Absorption cross sections for ground and excited states are determined and dipole moments of corresponding transitions are calculated. Numerical simulation results are presented.     

Antennas on quasi synthetic media

This paper examines the differences and/or similarities between some of the commonly used canonical equations describing the effective permittivity and permeability of heterogeneous substrates with dielectric or metallic inclusions, at microwave frequencies. Graphical results are presented for the different structures considered. Simulated results from heterogeneous mixtures with both dielectric and metallic inclusions are presented, and compared with results from the canonical equation representation. Simulated results of a patch antenna on a heterogeneous medium and on its homogeneous equivalent have also been presented.     

Two-dimensional isotropic scattering in a finite thick cylindrical medium exposed to a laser beam

Graphical and tabular results are presented for the back-scattered intensity from a finite two-dimensional cylindrical medium exposed to a Gaussian beam of radiation. Also, results for the source function and flux at the boundaries are presented. The influence of optical thickness and albedo are most pronounced at large optical radii. The semi-infinite results can be used to approximate the finite case for small optical radii. Ranges for single, double, and multiple scattering are discussed. For locations far from the incident beam, the results can be expressed in terms of universal functions independent of beam size. A method is presented for extending the isotropic results to the anisotropic case where the phase function is made up of a spike superimposed on an otherwise isotropic phase function.     

Results of the development of the technique for using nuclear photoemulsions in the experiment on the search for double neutrinoless beta decay

The last results on the preparation of the experiment on the search for double neutrinoless decay using emulsion chambers with molybdenum filling are presented. The results of testing emulsions prepared by the OJSC “Slavich Company” are presented. Algorithms for recognizing electron tracks in rectilinear and curvilinear portions are described.     

导电栅网对相对论速调管中电子束的约束作用

介绍利用导电栅网约束相对论速调管(RKA)中强流电子束的理论分析及实验结果.用近似的空间电荷场分布分析导电栅网约束实心电子束稳定传输时的电子运动情况，讨论束流稳定传输的条件；并介绍在一台直线感应加速器上利用导电栅网约束未调制强流束(约400kV，2.5kA)长距离(约60cm)传输的实验结果，同时给出利用导电栅网约束RKA中调制电子束的实验结果.理论分析及实验研究表明，导电栅网对实心束的约束作用对电子束能量相对不敏感；导电栅网可有效地用于RKA中取代磁场系统约束强流相对论电子束.     

The radiation impedance of a rectangular piston

The radiation impedance of a rectangular piston is expressed as the Fourier transform of its impulse response, which is obtained from the recent work of Lindermann [1]. The analytical evaluation of the transform is performed and new integral expressions are presented for both the radiation resistance and reactance. The integrals are readily evaluated in terms of elementary functions at both the low and high frequency limits. The integrals are also expressed as series of Bessel functions which are valid for all frequencies and aspect ratios. Numerical results are presented to illustrate the behavior of the radiation resistance and reactance as a function of the aspect ratio of the piston and a normalized frequency parameter. Additional numerical results are then presented to illustrate the accuracy of the analytical expressions for the radiation resistance and reactance at low and high frequencies. Finally, numerical results are presented to illustrate the application and accuracy of using standard FFT algorithms to evaluate the radiation resistance and reactance directly from the impulse responses.     

Thick GEM with a resistive coating

The results of testing a detector based on a thick gas electron multiplier (GEM) are presented. Impact of the TGEM dielectric charging on detector physical parameters is assessed based on simulation and experimental results. The further development of the detector—TGEM with resistive coating was constructed and tested. The test results are presented and compared to a standard thick GEM.     

Comparative experimental analysis of composite pulses in 14N NQR

Experimental results of comparing composite pulses in nitrogen-14 NQR, that are analogous to common 90 degrees RF pulses in powder, are presented. All tested pulses have been taken from publications in journals. Comparative diagrams of the measurement results for induction signals and echo signals are presented. The results of the measurements demonstrate that the best outcomes are achieved when the composite pulse (45)0(95)180(164)0 is used.     

Millimeter wave ferrite circulators and rotators

In this paper the exact analysis on the waveguide junction circulator and Faraday rotator are presented in detail. The correctness of analysis is demonstrated by its successful prediction about the performance of the devices. Many calculation results are presented by comparing with the experimental results. The approaches of expanding bandwidth of devices at W band are stated.     

Model for spatial microtubule oscillations

Under particular in vitro conditions, oscillating spatial and temporal waves of assembled microtubules can be observed. A reaction-diffusion model is presented to reproduce these results. This model is based on a set of chemical reaction equations and extended to include spatial dependence and diffusion. The basic properties of the model are presented and the results are demonstrated to connect the observable waves with turbidimetric measurements. The results of the model are consistent with experimental findings.     

A new graphical method relating to optical fiber attenuation

A new graphical method is presented for separating the causes of optical fiber losses. Some examples are given showing the use of this technique and some results derived from this technique are presented.     

Free vibration of antisymmetric,angle-ply laminated plates including transverse shear deformation by the finite element method

A finite element formulation of the equations governing the laminated anisotropic plate theory of Yang, Norris and Stavsky, is presented. The theory is a generalization of Mindlin's theory for isotropic plates to laminated anisotropic plates and includes shear deformation and rotary inertia effects. Finite element solutions are presented for rectangular plates of antisymmetric angle-ply laminates whose material properties are typical of a highly anisotropic composite material. Two sets of material properties that are typical of high modulus fiber-reinforced composites are used to show the parametric effects of plate aspect ratio, length-to-thickness ratio, number of layers and lamination angle. The numerical results are compared with the closed form results of Bert and Chen. As a special case, numerical results are presented for thick isotropic plates, and are compared with those for 3-D linear elasticity theory and Mindlin's thick plate theory.     

Mapping field density distribution in radiators by microwave noise

In his earlier paper on Active Microwave Radiometry, the author indicated that microwave noise can be used to map field density distribution inside radiators and in antenna systems, without the need for anechoic chambers.The presented paper gives details and results of such experiment. The method is described, details of equipment are given and results are presented with a concluding commentary.     

Study of characteristics of the “shashlik” type cellular electromagnetic calorimeter prototype

The results of measurements of nonuniformities of the response of heterogeneous cellular electromagnetic calorimeter prototypes are presented. The features of technology solutions used in developing calorimetric modules under study are presented.     

Achromatization of the self-imaging (Talbot) effect

The self-imaging effect is wavelength dependent. Polychromatic illumination results in a blurring of the self-images. A system is presented that compensates this longitudinal dispersion under retention of the image scales. Experimental results obtained with this system are presented.     

Response of a plate to a transient pressure wave load

The dynamical behaviour of a Kirchhoff plate under a moving pressure wave is investigated. The results are presented as dynamic amplification factors (DAF). The influence of the load parameters (propagation speed, pressure wave duration) and the plate parameters (slenderness, aspect ratio, damping, etc.) is discussed. Finally results for two examples are presented.     

对声波和弹性波传播模拟的Hamilton系统方法

建立了离散化网格上的准粒子体系，引入此体系的Hamilton系统描述，用来模拟声波和弹性波的传播.介绍了准粒子间相互作用的九点模型并给出互作用系数.证明了Hamilton系统方法 和声波、弹性波方程的关系，并给出两个方法中所使用物理量的关系.使用辛算法对给定的 介质模型进行数值模拟. 关键词： Hamilton系统方法 九点互作用模型 声波方程 弹性波方程 辛算法     

Digital Flat Panel Detectors in Medical Imaging Systems

Main parameters of digital flat panel detectors, to be taken into account in developing imaging systems are considered. Various factors affecting obtained images are presented. Experimental results presented confirm the necessity of image correction.     

Light Diffraction from Wood Tissue

Electromagnetic analysis of the interaction between light and wood tissue is presented. The wood structure is modelled as a periodic binary structure and the transmitted diffraction efficiencies are calculated using the Fourier modal method. Comparison between theoretical and experimental results from thin wood slice are also presented. The results explain the emergence of the experimentally observed oval scattering pattern on the surface of wood.     

A complex minkowski space approach to twistors

This paper is basically a review of known results in twistor theory. Its value is intended to lie in the connections presented between twistor concepts and structures in complex Minkowski space. The relationship of twistor theory to complex null infinity and a new proof of the Kerr theorem are presented; these results are to some extent original.