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Kraków, Poland

Guezguez I.,University of Angers | Guezguez I.,University of Monastir | Karakas A.,Selcuk University | Iliopoulos K.,University of Angers | And 8 more authors.
Optical Materials

Degenerate four-wave mixing (DFWM) experiments have been performed to determine the third-order nonlinear optical (NLO) susceptibilities (χ(3)) of gold(III) maleimide dithiolate tetraphenylphosphonium, (PPh4)[Au(midt)2], (Au-P) and gold(III) maleimide dithiolate melamine melaminium hybrid solvate, (C3N6H 6)(C3N6H7+)[Au(midt)2] -·2DMF·2H2O, (Au-Mel). Ab-initio quantum mechanical calculations (time-dependent Hartree-Fock (TDHF) method) of Au-P and Au-Mel have been carried out to compute the electric dipole moment (μ), the dispersion-free and frequency-dependent dipole polarizability (α) and the second hyperpolarizability (γ) values. These theoretical calculations are in good agreement with the experimentally obtained results by the DFWM technique. All the investigations show clearly the effect played by the counter ion on the resulting NLO properties of the two gold complexes. © 2013 Elsevier B.V. All rights reserved. Source

Domino K.,Instytut Fizyki
Physica A: Statistical Mechanics and its Applications

The WIG20 indexthe index of the 20 biggest companies traded on the Warsaw Stock Exchangereached the global maximum on 29th October 2007. I have used the local DFA (Detrended Functional Analysis) to obtain the Hurst exponent (diffusion exponent) and investigate the signature of anti-correlation of share price evolution around the maximum. The analysis was applied to the share price evolution for variable DFA parameters. For many values of parameters, the evidence of anti-correlation near the WIG20 maximum was pointed out. © 2011 Elsevier B.V. All rights reserved. Source

Bhalerao G.M.,University Pierre and Marie Curie | Polian A.,University Pierre and Marie Curie | Gauthier M.,University Pierre and Marie Curie | Iti J.-P.,Synchrotron Soleil | And 7 more authors.
Journal of Applied Physics

The ternary semiconductor alloy Zn1-x Bex Se has been studied under high pressure by x-ray diffraction and extended x-ray absorption fine structure (EXAFS) at the Zn and Se K -edge in order to determine the bulk and bond-specific elastic properties. Our measurements on samples with x=0.06-0.55 show pressure induced phase transformation from zinc blende to NaCl. The phase transformation pressure increases linearly with x. Murnaghan equation of state fitting to the data yields the unit cell volume at ambient pressure and bulk modulus, both of which follow the Vegard's law. Nearest neighbor bond distances derived from EXAFS do not show sharp phase transition except for x=0.06. Bond modulus derived for the Zn-Se bonds shows them to be apparently stiffer than the bulk alloy, which is nontrivial. This tendency increases with increasing x and a strong positive bowing from the Vegard's law is observed. We attribute the observed anomalies to the contrastingly different properties of the two components ZnSe and BeSe. © 2010 American Institute of Physics. Source

Bouchouit K.,Jijel University | Kouissa B.,Jijel University | Migalska-Zalas A.,Instytut Fizyki | Brihi N.,Jijel University | Sahraoui B.,University of Angers
Optical and Quantum Electronics

A new and efficient semi organic nonlinear optical crystal from the amino acid family has been grown by slow evaporation technique from aqueous solution. The crystals structures were solved by direct methods using SIR92 (WINGX) and refined by a full matrix least-square method using SHELXL97. All this compounds crystallized in noncentrosymetric groups. Second harmonic generation measurements were performed by applying the Kurtz and Perry model, to powder samples of compounds at 1,064 nm. © 2013 Springer Science+Business Media New York. Source

Domino K.,Instytut Fizyki
Physica A: Statistical Mechanics and its Applications

The local properties of the time series of the evolution of share prices of 126 significant companies traded on the Warsaw Stock Exchange during the period between 19912008 have been investigated. The analysis was applied to daily financial returns. I have used the local DFA to obtain the Hurst exponent (diffusion coefficient) while searching for negative correlations by which changes of long-term trends would be effected. A certain evidence, proving that after the signature of anti-correlationthe drop in the Hurst exponentthe change in the trend and in the return rate of an investment is probable, was pointed out. Hence after further investigation this method may be useful as a part of an investment strategy. As the Warsaw Stock Exchange is relatively smaller and younger than other significant world Stock Exchangesand as the developing market is less efficientthe generalization for others markets needs further investigation. © 2010 Elsevier B.V. All rights reserved. Source

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