Wyniki wyszukiwania - BazTech

1

Interface effects on the NLO properties of guest-host materials

Makowska-Janusik M., Kassiba A. H., Failleau G., Boucle J.

Materials Science Poland

|

2006

|

Vol. 24, No. 4

891--900

EN

Electro-optical properties of silicon carbide (SiC) nano-sized clusters embedded into three different polymeric matrices, i.e., poly(methyl methacrylate, poly-N-vinylcarbazole and polycarbonate were investigated. Electric properties of SiC were calculated using time-dependent DFT methods considering an isolated cluster and environmental effects. The concept of the polymeric influence on optical properties of chromophores was executed by the local electric field approach. Electric field created by charge distribution of the surrounding polymer was calculated using guest-host structures obtained by the molecular dynamics simulations. Optical properties of SiC situated in polymeric environments differ from those of free clusters. It is seen more significantly for the hyperpolarizability than for the polarizability. The spatial distribution of SiC in the matrix depends on the kind of polymer and gives an important influence on the obtained local electric field value. The Si-C distances do not change with variation of the polymeric matrix. The geometry of 3C-SiC is very stable and does not change during MD simulations performed at 300 K.

2

Numerical-experimental studies on penetration of multilayered targets containing ceramics

Jach K., Lis J., Mroczkowski M., Świerczyński R., Wiśniewski A.

Journal of Technical Physics

|

2002

|

Vol. 43, no 1

35-41

EN

In the paper we present the results of numerical and experimental studies of the impact of penetrators onto ceramic-composite and ceramic-metal targets. The main purpose of this paper is to show the possibilities of computer-aided interpretation of experimental results using "free particles" hydrocodes modelling of multilayered targets containing ceramics. Model for ceramics is based on the modified Steinberg's constitutive relations for non-damaged, ideal ceramic material. The model of the composite is based on the isotropic multilayered model of composite panels with different material characteristics in each layer. The numerical simulations and experiments were carried out for several combinations of ceramic/metal and ceramic/composite layers: Al2O3/aluminium, SiC/AlN/steel, AIN/SiC/steel, SiC/Al2O3/steel, AIN/Al2O3/steel and Al2O3/Dyneema. The exemplary results of our studies are shown. The results of theoretical and experimental investigations are in good agreement with one another.

3

Formation of microoptical elements in the bulk of composition material on the basis of porous glass.

Klim O.V., Meshkovsky I.K.

Optica Applicata

|

2000

|

Vol. 30, nr 4

577-579

EN

The possibilities of the formation of microoptical elements in the bulk of composite material on the basis of porous glass have been investigated. It has been demonstrated that due to the local laser heating-up of composition material, the local desorption of the adsorbate from a porous matrix is initiated that causes formation of microlenses. Other possibilities of microoptical filters formation have been studied based on electrodiffusion immobilization of dye ions. Characteristics of such elements are studied and possible applications are discussed.

4

Study of perforation of metals and composite materials paltes by projectile.

Al-Qureshi H.A., Ishikura D.

Inżynieria Materiałowa

|

1998

|

R. XIX, nr 3

544-547

EN

This paper presents theoretical and experimental analyses of the effect of low/intermediate velocity projectile impact for perforation of metallic and composite material plates. The theory is based on the plastic deformation energy taking into account the work hardening characteristics of the material. Materials with different work hardening characteristics and composite lamianates were used. Generally, it was found that the theoretical predictions for the absorbed energy are in good agreement with the experimental results.

5

Two-point Pade approximants for Stieltjes functions and their application to composite materials

Tokarzewski S., Telega J. J.

Applied Mathematics and Computer Science

|

1998

|

Vol. 8, no 2

417-434

EN

By employing special continued fractions to asymptotic expansions at zero and infinity, the convergence of the balanced and unbalanced two-point Pade approximants (2PPA) to a Stieltjes function is studied in a real domain. We prove that certain balanced and unbalanced two-point Pade approximants form a monotone sequence of upper and lower bounds uniformly converging to a Stieltjes function. The observed monotone and uniform convergence of 2PPA is exemplified in the evaluation of bounds on the effective transport coefficients of periodic inhomogeneous media.