Hydrogen bond and exchange interaction in the (CuSO<Subscript>4</Subscript>)(en)·2H<Subscript>2</Subscript>O and (CuSO<Subscript>4</Subscript>)(en)·2D<Subscript>2</Subscript>O organometallic compounds

The influence of the replacement of hydrogen with deuterium in molecules of water of crystallization in the structure of the (CuSO₄)(en) · 2H₂O and (CuSO₄)(en)·2D₂O organometallic compound molecules on exchange interaction between copper ions was studied. The X-ray structural data and the data on angular anisotropy of the effective g-factor of Cu²⁺ ions in both compounds show that distortions of the initial structure caused by deuteration are minimum. A comparative analysis of the width of the exchange coupled EPR lines of the two compounds is indicative of a decrease in the exchange parameter in the deuterated sample, which substantiates the participation of H-bonds in exchange interactions in the systems studied.     

Stability of the Minimizers of Least Squares with a Non-Convex Regularization. Part II: Global Behavior

We address estimation problems where the sought-after solution is defined as the minimizer of an objective function composed of a quadratic data-fidelity term and a regularization term. We especially focus on non-convex and possibly non-smooth regularization terms because of their ability to yield good estimates. This work is dedicated to the stability of the minimizers of such piecewise C^m, with m ≥ 2, non-convex objective functions. It is composed of two parts. In the previous part of this work we considered general local minimizers. In this part we derive results on global minimizers. We show that the data domain contains an open, dense subset such that for every data point therein, the objective function has a finite number of local minimizers, and a unique global minimizer. It gives rise to a global minimizer function which is C^m-1 everywhere on an open and dense subset of the data domain.     

Investigation of solid sample microhomogeneity by laser microanalysis

Summary The microhomogeneity of the distribution of doped neodymium in YAG:Nd³⁺ single crystals and of impurities in an aluminium alloy standard are studied by means of laser emission microanalysis. The applied statistical methods are briefly described: one-way variance analysis, two-way variance analysis, calculation of regression models of the element concentration distribution in samples, gradient method and cluster analysis.

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Untersuchung der Mikrohomogenität fester Proben durch Laser-Mikroanalyse

     

Spectroscopic Elucidation of the Coordination Ability of 2-Oxo-2H-Chromene-3-Phosphonic Acid with Pt(II)

The coordination ability of 2-oxo-2H-chromene-3-phosphonic acid with Pt(II) both in solution and in solid state is elucidated by means of conventional and linear-polarized IR spectroscopy of oriented colloid suspensions in nematic liquid crystal, ¹H-, ¹³C-, and ³¹P-NMR, UV-Vis spectroscopy, positive and negative mass spectrometry (ESI and FAB), and TGV and DSC methods. A comparison with the spectroscopic data of ammonium salt of 2-oxo-2H-chromene-3-phosphonic acid is carried out as well.     

Synthesis,thermal investigations and kinetic data of Zn(BF<Subscript>4</Subscript>)<Subscript>2</Subscript>·6H<Subscript>2</Subscript>O

The thermal dehydration and decomposition of Zn(BF₄)₂·6H₂O have been studied by TG, DTA and DSC analyses. It is found that the dehydration occurs in two steps. Following the experimental results a thermal decomposition scheme of the compound under investigation is proposed. The enthalpies of dehydration have been determined as well as the formal kinetic parameters are presented.     

Influence of the discharge gas on the emission and thermal characteristics of laser-induced microplasmas

Summary An investigation has been made of the influence of argon, oxygen, and argon/oxygen blends in various ratios as the protective gas medium, on the intensities of the spectral lines, the amount of substance evaporated, and the excitation temperatures in the evaporation of an aluminium sample with the aid of laser irradiation and subsidiary excitation of the microplasma obtained. Maximum intensifying effect was observed when a pure argon medium was used. The gas medium does not influence the amount of substance evaporated from the sample. Within the experimental error of the twoline method used, the excitation temperatures do not appear to be influenced by the type of gas blend. An auxiliary voltage device was added to the laser equipment, which allows evaporation of the substance in an atmosphere of inert gas and in minute absolute amounts, with high energy in the discharge gap. This new approach improves the limits of detection.

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Zusammenfassung Der Einfluß der Schutzgasatmosphäre aus Argon, Sauerstoff oder Argon/Sauerstoff-Mischung in verschiedenen prozentualen Verhältnissen auf die Intensitäten der Spektrallinien, die Menge der verdampften Substanz und die Anregungstemperaturen wurde bei der Verdampfung einer Aluminiumprobe mit Hilfe von Laserstrahlung und mit Nebenanregung des Mikroplasmas untersucht. Ein maximaler Verstärkungseffekt wurde in reinem Argon beobachtet. Das Gasmedium übt keinen Einfluß auf die Menge der verdampften Probensubstanz aus. Im Rahmen der Fehler und der Genauigkeit der angewandten Zweilinienmethode wurden die Anregungstemperaturen von der Art der Gasmischung nicht beeinflußt. Die Laserausrüstung war mit einer Vorrichtung für Hilfsspannung ausgestattet, welche die Verdampfung und Anregung der Probensubstanz in einer Inertgasatmosphäre und in minimalen absoluten Mengen unter Hochenergiebildung in der Entladungsstrecke ermöglichte. Damit konnten die Nachweisgrenzen der Mikroelemente erweitert werden.

     

Generalized coupling constants for broken gauge symmetries in geometrical terms

A geometrical treatment of the gauge coupling constant is proposed in terms of a generalized connection form using fibre-bundle language. This extends the notion of the coupling constant to a notion of a field. The reduction of a curvature form for the generalized connection form is described in the case of a reduction of a structure group G to a subgroup H (broken gauge symmetry), and a coupling constant for the gauge group H is constructed from the corresponding one for the gauge group G.