Study of Amorphous Ferrimagnet Fe0.66Er0.19B0.15 by Means of Monochromatic Circularly Polarised Source

Properties of amorphous alloy Fe_0.66Er_0.19B_0.15 are reported. A reorientation of the Fe and Er magnetic moments during sample cooling through the compensation point in a large magnetic field is found by means of monochromatic circularly polarised radiation. This revised version was published online in August 2006 with corrections to the Cover Date.     

A refinement of the right-hand side of the Hermite–Hadamard inequality for simplices

Aequationes mathematicae - We establish a new refinement of the right-hand side of the Hermite–Hadamard inequality for simplices, based on the average values of a convex function over the...     

Miniaturized optical chemosensor for flow-based assays

A cost-effective, highly compact, and versatile optoelectronic device constructed of two ordinary light emitting diodes compatible with optosensing films has been developed. This fibreless device containing chemoreceptor, semiconductor light source, and detector integrated in a miniaturized flow-through cell of low microliter internal volume works as a complete photometric chemical sensor suitable for detection in flow analysis. The operation of the developed device under nonstationary programmable-flow conditions offered by sequential injection analysis has been demonstrated using Prussian Blue film as a model optical chemoreceptor. The unique spectroelectrochemical properties of the sensing material enable its use for optical sensing of redox species, whereby ascorbic acid and hydrogen peroxide have been chosen as model analytes. The reported SI-sensor system features fast and reproducible determination of both analytes in the submillimolar range of concentrations. The construction concept demonstrated in this work can be easily applied to other kinds of optical sensors based on absorbance sensing films.     

Applications of hybrid universality to multivariable zeta-functions

In the present paper, we obtain new results on universality as applications of hybrid universality and almost-periodicity in its half-plane of absolute convergence. By using these, we show the universality for Euler products of Igusa type, Euler-Zagier multiple zeta-functions and Tornheim-Hurwitz type of double zeta-functions.     

Product numerical range in a space with tensor product structure

We study operators acting on a tensor product Hilbert space and investigate their product numerical range, product numerical radius and separable numerical range. Concrete bounds for the product numerical range for Hermitian operators are derived. Product numerical range of a non-Hermitian operator forms a subset of the standard numerical range containing the barycenter of the spectrum. While the latter set is convex, the product range needs not to be convex nor simply connected. The product numerical range of a tensor product is equal to the Minkowski product of numerical ranges of individual factors.     

Experimental and Theoretical Investigation of Vibrational Spectra of Coordination Polymers Based on TCE‐TTF

The room‐temperature infrared and Raman spectra of a series of four isostructural polymeric salts of 2,3,6,7‐tetrakis(2‐cyanoethylthio)‐tetrathiafulvalene (TCE‐TTF) with paramagnetic (Co^II, Mn^II) and diamagnetic (Zn^II, Cd^II) ions, together with BF₄^? or ClO₄^? anions are reported. Infrared and Raman‐active modes are identified and assigned based on theoretical calculations for neutral and ionized TCE‐TTF using density functional theory (DFT) methods. It is confirmed that the TCE‐TTF molecules in all the materials investigated are fully ionized and interact in the crystal structure through cyanoethylthio groups. The vibrational modes related to the C?C stretching vibrations of TCE‐TTF are analyzed assuming the occurrence of electron–molecular vibration coupling (EMV). The presence of the antisymmetric C?C dimeric mode provides evidence that charge transfer takes place between TCE‐TTF molecules belonging to neighboring polymeric networks.