The stabilization of charged states at phenazine-like units in polyaniline under p-doping: an in situ ATR-FTIR spectroelectrochemical study

The structure and stabilization of charged states during p-doping of polyaniline (PANI) were studied by in situ ATR-FTIR spectroelectrochemistry. The role of phenazine-like units in several copolymers of aniline and a phenazine derivative (3,7-diamino-5-phenylphenazinium chloride, phenosafranine) was investigated by spectroelectrochemistry. PANI and three copolymers with different aniline to phenosafranine ratio were electrochemically prepared. FTIR spectra of as-prepared polymers as well as in situ FTIR spectra during the oxidation of the polymers give evidence of the presence of phenazine-like units in the structure of electrochemically prepared PANI, as shown by vibrations of the phenazine rings. New bands corresponding to the in-plane and out-of-plane C-H vibration of 1,2,4-trisubstituted benzene nuclei in the phenazine skeleton are found at 1033, 957, 880, 766 and 681 cm(-1). The potential dependence of IR bands observed during oxidation of the polymers was compared to that of the ESR intensity and the absorption data and points to the diamagnetic species like π-dimers formed at higher oxidation level of PANI. This charged state is shown to be fixed at the link of the phenazine-like units with the linear segments of PANI.     

Conditions of complete normality for dynamical systems on Riemannian manifolds

New equations that transform the previously found conditions of weak normality into conditions of complete normality are established for Newtonian dynamical systems on Riemannian manifolds.Bashkir State University, Ul. Frunze 32, 450074 Ufa (email: root@bgua.bashkiria.su). Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 103, No. 2, pp. 267–275, May, 1995.     

Meteorological effects in the intensity of muon groups

The data of the experimental study of cosmic ray muon groups using the DEKOR setup for the period of 2004–2007, during which significant changes in the intensity of groups at the Earth’s surface were detected, are analyzed. It was found that these variations are caused by variations of weather conditions (temperature and atmospheric pressure); barometric and temperature coefficients were determined. It turned out that magnitudes of these coefficients for muon groups are significantly higher than available values for singlemuons. Possible physicalmechanismof the effect is discussed. Since muon groups are formed at high altitudes (of the order of several kilometers), the detected effect can be used for monitoring air temperature variations in the upper troposphere.     

Energy spectrum of cascade showers generated in water by near-horizontal muons

We discuss measuring cascade shower energy using the NEVOD Cherenkov water detector with a spatial lattice of quasi-spherical modules (QSMs). Dense QSM spacing makes it possible to reconstruct a number of cascade particles along the shower axis from the PMT response amplitude. Our cascade curve reconstruction technique is applied to showers generated by near-horizontal high-energy muons selected using the DECOR coordinate detector deployed around NEVOD. The first results from cascade energy spectrum measurements are reported.