Zur Chemie von Polyhalocyclopentadienen, 24. Mitt.: Alkalistabile hochchlorierte nichtaromatische Carbonsäuren,III

Zusammenfassung Es wird über cis-und trans-Hexachlor-bis-endomethylennaphthalin-dicarbonsäure sowie die Herstellung einiger anderer, das Hexachlor-bicyclo[2.2.1]hepten-System enthaltender Carbonsäuren berichtet.Mit 2 Abbildungen23. Mitt.: Dtsch. Bundes-Patentanm. R 23 306 IV b/12 o vom 10. Mai 1958.II ist die vorhergehende Mitteilung, l. c. Fußnote 1; I=l.c. Fußnote 4.     

On Truncated Matricial Stieltjes Type Moment Problems

We study two slightly different versions of truncated generalized matricial moment problems of Stieltjes type. A central topic is the construction and investigation of distinguished solutions of both moment problems under consideration. These solutions turn out to be nonnegative Hermitian Borel measures on the real axis which are concentrated on a finite number of points. Our approach is mainly algebraic. It is based on the use of particular matrix polynomials constructed from a nonnegative Hermitian block Hankel matrix.     

Shift operators contained in contractions, pseudocontinuable Schur functions and orthogonal systems on the unit circle

The main aim of this paper is to establish the connection between well-known criteria for the pseudocontinuability of a non-inner Schur function ?? in the unit disk (see Theorems 3.9, 4.2). In a canonical way we associate a probability measure ?? on the unit circle with ??. One of the two criteria will be reformulated in the face of ??, whereas the other one is drafted in view of a completely nonunitary contraction T having ?? as corresponding characteristic function. Our main result clarifies an immediate connection between the above-mentioned two criteria. In this way, we rewrite these criteria in terms of orthogonal systems with respect to the measure ?? (see Theorem 7.2).     

Internal structure of nanoporous TiO2/polyion thin films prepared by layer-by-layer deposition

The internal structure of porous TiO2 films prepared by electrostatic layer-by-layer deposition was investigated. The films were prepared by alternate dipping of solid substrates into dispersions of TiO2 nanoparticles and polycations, polyanions, or pure buffer solution, respectively. The surface charge of the amphoteric TiO2 particles was controlled by the pH of the aqueous dispersions. The morphology of the film surface was investigated by means of scanning electron microscopy. It was found that the surface roughness strongly depends on the polymeric material used for the deposition process but is independent of the ionic strength of the solution or the molecular weight of the polyions. The samples with rough surfaces feature strong light scattering. The porosity and internal structure of the TiO2/polyelectrolyte films were investigated by adsorption/desorption of dye molecules. A crude estimate yields an internal surface that is up to 160 times the plane surface of the substrate for a film thickness of 1 microm. The composition of the films was investigated by X-ray photoelectron spectroscopy (XPS). Detection of the XPS signal after each deposition step of the first three dipping cycles shows a significant increase of the relative surface coverage of Ti after the TiO2 deposition step and of PSS after the PSS deposition step. For later dipping cycles, such an increase was also detectable but less prominent.