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Previous issue vol. 45, no. 1 (2004)

vol. 45, no. 2 (2004)

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Contents of issue 2, vol. 45

1. J. Rychlewska, J. Szymczyk, C. Woźniak: Simplified models for the vibration analysis of micro-periodic elastic media
2. A. Wiśniewski: Computer simulation of ceramic armours firing with armour piercing bullets
3. W. Nasalski: Three-dimensional beam scattering at multilayers: formulation of the problem
4. A. Trzęsowski: Tensility and compressibility of axially symmetric nanoclusters. Part I: Simplified modelling
5. Y. Tasinkevych: Methods of IDT charge spatial spectrum evaluation

6. A. Szczepański: Quantum information transfer without classical channel: a proposed energy-correlation experiment

J. Rychlewska, J. Szymczyk, C. Woźniak: Simplified models for the vibration analysis of micro-periodic elastic media

The aim of this paper is to propose and apply a new approach to the formation of simplified models for the vibration analysis of a micro-periodic linear-elastic composite medium. First, we propose a discrete model which can be used to investigations of both long and short waves. The main feature of the obtained discrete model is the finite-difference form of governing equations. The continuum models are derived directly from the discrete one under the assumption that the macroscopic wavelength is large when compared to the length dimension of a periodicity cell. The proposed models describe both the low-frequency and high-frequency vibration problems and can be formulated on different levels of accuracy. The reliability of the procedure leading from discrete to continuum models is discussed on the illustrative example.

Key words: elastodynamics, composites, modelling.

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A. Wiśniewski: Computer simulation of ceramic armours firing with armour piercing bullets

Model of elastic and plastic body behaviour of bullet and metal elements of armour, and model of elastic, plastic and brittle body behaviour of ceramics are presented in this paper. Apart from this, the modelling of penetration of ceramics with dimensions of 50x50mm 100x100mm, situated on different foundations, with AP (armour-piercing) bullets of calibre 12.7mm, is shown.

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W. Nasalski: Three-dimensional beam scattering at multilayers: formulation of the problem

A problem of three-dimensional optical beam scattering at a dielectric multilayer is analysed. Scattering and transfer matrices of the layered structure are derived for incidence of beams of arbitrary polarization. Transmission and reflection matrices are given in a diagonal form dependent on polarization of an incident beam. Factorisation of these matrices results in scalar complex transformations, separately for beam polarization and for beam amplitudes. While the polarization transformations describe the multilayer action in terms of Lorentz transformations, the amplitude transformations yield spatial beam shaping. The scattering vector problem resolves into two independent scalar transformations.

Keywords: beams, polarization, refraction, reflection, multilayers.

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A. Trzęsowski: Tensility and compressibility of axially symmetric nanoclusters. Part I: Simplified modelling

A simplified method to model the temperature-dependent uniaxial tensility and volume compressibility of axially symmetric nanoclusters is proposed. Particularly, formulae for the isothermal generalized Young's and bulk moduli of nanoclusters being in the quasi-solid state are given and a model of isothermal uniaxial tension dynamics is proposed.

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Y. Tasinkevych: Methods of IDT charge spatial spectrum evaluation

Interdigital transducers (IDTs) have found numerous applications in electronic devices for excitation and detection of surface acoustic waves (SAWs). This paper discusses the methods of solution of the electrostatic problem arising in modelling of the IDT most important characteristic - its frequency response. Numerical results are presented based on the so-called spectral approach. Computation difficulties are discussed and their solutions are proposed.

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A. Szczepański: Quantum information transfer without classical channel: a proposed energy-correlation experiment

Energy entangled photon pairs from parametric down conversion are the considered bipartite quantum system. It is argued that photocount of the energy-analysed photon in one subsystem does not commute with measurements of higher order correlation functions (interferences) in the second subsystem. Both the subsystems are mutually spatially disjoint. Very short measurement sampling times needed to perform the discussed experiment make it rather "gedanken" than real.

Contents