Effective dimensionality approach to the RKKY interaction in multilayer systems

We consider RKKY interaction in a quasi 2D system with nonparabolic dispersion. In our paper we calculate the RKKY range function assuming the in-layer confinement via effective dimensionality approach. We show, that indirect magnetic exchange in our system can be modelled by the effective spectral dimension which equals one.     

Two-Color Two-Photon Excitation of Fluorescence

Abstract— We report the observation of two-photon excitation of an organic fluorophore with two different wavelengths, a phenomenon we refer to as two-color two-photon (2C2P) excitation. Ultraviolet emission of p -Merphenyl at 340 nm was observed when the sample was illuminated with both 375 and 750 nm pulses from a picosecond dye laser. The emission of p -terphenyl was about 100-fold and more than 1000-fold less for illumination at only 375 or 750 nm, respectively. Observation of the 2C2P signal required temporal and spatial overlap of the 375 and 750 nm pulses. The amplitude of the signal depended on the polarization of each beam. 2C2P excitation can have applications in fluorescence microscopy and elsewhere when spatially localized excitation is desirable.     

Selenirene as an intermediate in the pyrolysis of 1,2,3-selenadiazole. Microwave spectra of 13C labelled selenoketene

Microwave Spectra of ¹³CH₂¹²C^80,78Se and ¹²CH₂¹³C^80,78Se (selenoketene) are recorded. B 5-¹³C-1,2,3-selenadiazole all four species are formed. The ¹³C scrambling may take place via a three-membered ring, selenirene, but as expected its microwave spectrum was not observed.     

Determination of dipole moment in the ground and excited state by experimental and theoretical methods of N-nonyl acridine orange

The absorption and fluorescence spectra of N-nonyl acridine orange are determined at room temperature (298 K) in cyclohexane, benzene, carbon tetrachloride, chloroform, chlorobenzene and dichloromethane. The ground state of dipole moment was obtained by impedance measurements using Guggenheim-Debeye's method. The experimental excited state dipole moment of N-nonyl acridine orange was determined using Bakhshiev's and Kawski-Chamma-Viallet's formulae and solvent polarity parameter proposed by Reichardt. These experimental results were completed with theoretical results using quantum chemical methods. The experimental (muexp=10.76 D) and theoretical (mucal=9.9 D) dipole moments in the ground and excited state (muexp*=14.56 D) were compared.     

Spectrophotometric determination of Fe(II) in milligram solid samples

The analytical procedure of determination of Fe(II) in the presence of Fe(III) in milligram samples is proposed. A solid sample is dissolved in hydrochloric acid in argon atmosphere. Subsequently, the pH-value of the solution is fixed and Fe(III) complexed by phosphoric buffer. At the next step Fe(II) is oxidized by -molybdosilicic acid. Finally, the intensity of colouring caused by the reduced form of the acid is measured at the wavelength 770 nm. The proper treatment of the sample during oxidation, and immediately before, is decisive for the accuracy of the analysis. The method was verified by means of the analysis of synthetic magnetite. The theoretical content of Fe(II) was 24.12%, the determined one was 24.02 ± 0.10%. The method was applied to the determination of the homogeneity of an iron catalyst for ammonia synthesis.