Piezoelectric textures based on poly(vinyl chloride) filled with dispersed lead zirconate titanate (PZT-19)

This paper reports on the results in investigations into the properties of piezoelectric textured materials that are formed through technological treatment of a mixture of components of dispersed poly(vinyl chloride) and a ferroelectric powder with the application of an external mechanical shear stress and an electric field.     

Higher order symmetrizer and application to an unusual transport equation

We study a class of stationary transport equation with nonlocal low-order tems We obtain the existence and uniqueness of a solution in sobolev spaces     

An algorithm for three-dimensional Voronoi S-network

The paper presents an algorithm for calculating the three-dimensional Voronoi-Delaunay tessellation for an ensemble of spheres of different radii (additively-weighted Voronoi diagram). Data structure and output of the algorithm is oriented toward the exploration of the voids between the spheres. The main geometric construct that we develop is the Voronoi S-network (the network of vertices and edges of the Voronoi regions determined in relation to the surfaces of the spheres). General scheme of the algorithm and the key points of its realization are discussed. The principle of the algorithm is that for each determined site of the network we find its neighbor sites. Thus, starting from a known site of the network, we sequentially find the whole network. The starting site of the network is easily determined based on certain considerations. Geometric properties of ensembles of spheres of different radii are discussed, the conditions of applicability and limitations of the algorithm are indicated. The algorithm is capable of working with a wide variety of physical models, which may be represented as sets of spheres, including computer models of complex molecular systems. Emphasis was placed on the issue of increasing the efficiency of algorithm to work with large models (tens of thousands of atoms). It was demonstrated that the experimental CPU time increases linearly with the number of atoms in the system, O(n).     

求解复杂湍流的非线性涡黏性系数模型和代数应力模型

非线性涡黏性系数模型和代数应力模型联系了线性涡黏性系数湍流模型和完整的微分 雷诺应力模型.随着它们受到日益关注,其形式也越来越多样化.本篇综述的目的是对这些模 型加以总结并比较它们之间的共同点及不同之处,指出它们与完整微分雷诺应力模型之间的 关系,以及相对于线性涡黏性系数模型而言它们在预报流场上所具有的优势.     

Self-rolled polymer microtubes with engineered hidden walls

Micro and nanotubes are manufactured by self-rolling of thin bilayer polymer films (polystyrene/poly(4-vinyl pyridine, PS/P4VP) gradually released from a solid substrate. Swelling of the P4VP layer in acidic water opposed by a stiff PS layer leads to rolling of the film into tubings of micrometer diameters. The position and the arrangement of the tubes on the substrate are defined by UV photolithography structuring of the polymer film. A few nanometer thick metallic patterns, such as arrays of conductive stripes and simple electrical circuits, are formed on the top of the polymer film by magnetron sputtering and transferred to the tube interior by rolling. Intra-tubular rolled-up microsolenoids are applied to generation of localized magnetic fields inside the tubes and in their vicinity.     

Interfacial relaxation in fiber textures based on poly(dodecanamide)

The electrical relaxation in composite textures based on poly(dodecanamide) filled with polyamide fibers has been investigated using dielectric relaxation and thermally stimulated current measurements over wide ranges of frequencies and temperatures. The mechanisms of electrical relaxation in the range of the structural transition and at interfaces in the composite are established.