The characterization of Cr secondary oxide phases in ZnO films studied by X-ray spectroscopy and photoemission spectroscopy

X-ray absorption near-edge structure (XANES), X-ray emission spectroscopy (XES), and X-ray photoemission spectroscopy (XPS) were used to characterize the Cr secondary oxide phases in ZnO films that had been prepared using a co-sputtering method. Analysis of the Cr L_3,2-edge XANES spectra reveals that the intensity of white-line features decreases subtly as the sputtering power increases, indicating that the occupation of Cr 3d orbitals increases with Cr concentration in (Zn, Cr)O films. The O K-edge spectra show that the intensity of XANES features of (Zn, Cr)O films is lower than those of ZnO film, suggesting enhanced occupation of O 2p-derived states through O 2p-Cr 3d hybridization. The XES and XPS spectra indicate that the line shapes in the valence band of (Zn, Cr)O films are quite different from those of ZnO and that the Cr₂O₃ phase dominates the spinel structure of (Zn, Cr)O films increasingly as the Cr sputtering power is increased. Over all results suggest that the non-ferromagnetic behavior of (Zn, Cr)O films can be attributed to the dominant presence of Cr₂O₃, whereas the bulk comprise phase segregations of Cr₂O₃ and/or ZnCr₂O₄, which results them the most stable TM-doped ZnO material against etching.     

A simple one-pot synthesis of phosphinoselenoic amides and diamides from secondary phosphine selenides and amines using Et3N-CCl4

The multi-component reaction between secondary phosphine selenides and amines (primary, secondary, and primary diamines) proceeds using the Et₃N-CCl₄ system under mild conditions to give phosphinoselenoic amides or diamides in 81-89% isolated yields.     

Cancellation Problems and Dimension Theory

In this note, we study the global dimension of coalgebras and discuss the class of coalgebras of global dimension less or equal to 1. The coalgebras in this class, which contains all the cosemisimple coalgebras, are called hereditary coalgebras. If C is a finite dimensional coalgebra, then C is hereditary if and only if C (the convolution algebra of C) is a hereditary algebra. Any direct sum of hereditary coalgebras is hereditary too. This gives us many examples of infinite dimensional hereditary coalgebras. A coalgebra is left hereditary if and only if it is right hereditary. Moreover, there do not exist hereditary Hopf algebras of finite dimension which are not cosemisimple.     

Global existence of weak solutions for two-dimensional semilinear wave equations with strong damping in an exterior domain

We consider two-dimensional mixed problems in an exterior domain for a semilinear strongly damped wave equation with a power-type nonlinearity |u|^p${\left|u\right|}^p$. If the initial data have a small weighted energy, we shall derive a global existence and energy decay results in the case when the power p$p$ of the nonlinear term satisfies p>6$p>6$.     

Errata to: “Vector-valued Modulation Spaces and Localization Operators with Operator-valued Symbols”

In our article “Vector-valued Modulation Spaces and Localization Operators with Operator-valued Symbols”, Integr. equ. oper. theory 59 (1) (2007), 99–128, Example 4.4 is false. We present a corrected example.      

Strongly Supercommuting Self-Adjoint Operators

We introduce the notion of strong supercommutativity of self-adjoint operators on a -graded Hilbert space and give some basic properties. We clarify that strong supercommutativity is a unification of strong commutativity and strong anticommutativity. We also establish the theory of super quantization. Applications to supersymmetric quantum field theory and a fermion-boson interaction system are discussed.     

Drinfeld-Sokolov reduction on a simple lie algebra from the bihamiltonian point of view

We show that the Drinfeld-Sokolov reduction can be framed in the general theory of bihamiltonian manifolds, with the help of a specialized version of a reduction theorem for Poisson manifolds by Marsden and Ratiu.This work has been supported by the Italian MURST and by the GNFM of the Italian C.N.R.     

POLYMORPHISM OF ISOTACTIC POLYPROPYLENE IN PRESENCE OF ADDITIVES,IN BLENDS AND IN COMPOSITES

This article is an overview of our investigations of polymorphism in isotactic polypropylene. We suggest the reason for the formation of different forms is perturbations in the mobility of the chains during crystallization. In this work, we try to prove this hypothesis considering the influence of the presence of small organic compounds or external forces, like an electric field, on the process of crystallization. We also analyzed the formation of the polymorphic forms in polypropylene blends and in composites with natural fibers. It was found that in the composites with natural fibers the hexagonal form arises when the fibers are in motion in relation to the polymeric matrix.