Ein verallgemeinerter Kettenbruch-Algorithmus zur rationalen Hermite-Interpolation

Summary In this paper we consider rational interpolation for an Hermite Problem, i.e. prescribed values of functionf and its derivatives. The algorithm presented here computes a solutionp/q of the linearized equationsp–fq=0 in form of a generalized continued fraction. Numeratorp and denominatorq of the solution attain minimal degree compatible with the linearized problem. The main advantage of this algorithm lies in the fact that accidental zeros of denominator calculated during the algorithm cannot lead to an unexpected stop of the algorithm. Unattainable points are characterized.

Herrn Prof. Dr. Dr. h.c.mult. L. Collatz zum 70. Geburtstag gewidmet     

Vollautomatische titrimetrische Einzelanalyse in der Praxis

Zusammenfassung Voraussetzungen einer effektiven Automation der individuellen titrimetrischen Analyse werden dargestellt. Ein nach diesen Gesichtspunkten entwickeltes Gerät wird beschrieben und seine Anwendung in den Gebieten der Farbstoffe, Agrochemikalien, Additiven und Pharmaka aufgezeigt.

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Fully automated titrimetric individual analysis in practice

Summary Criteria for effective automation of individual titrimetric analyses are presented. Based on these, an automatic titration system has been developed which is described. Its performance and its applicability in the field of dyestuffs, agrochemicals, additives and pharmaceuticals has been investigated.

     

La9Sb16Br3 and Ce9Sb16Cl3: stars and stripes in rare earth halide and intermetallic compounds

The title compounds were synthesized from Ln, LnX(3) (Ln = La, Ce; X = Cl, Br), and Sb under an Ar atmosphere at 950 degrees C. They crystallize in the space group P6(3)/m (No. 176) with lattice constants a = 21.232(5) and 20.862(2) Angstroms and c = 4.323(2) and 4.2728(7) Angstroms for La(9)Sb(16)Br(3) and Ce(9)Sb(16)Cl(3), respectively. The solids are the most metal-rich members in the reduced rare earth metal halide family and contain partial structures which are characteristic of reduced halides and intermetallic phases. These are the [Ln(6)X(6)](infinity) hexagon stars, Sb-centered [Ln(3)Sb](infinity) trigonal prismatic columns, and stripes of Sb square meshes. Computational analysis indicates that their electronic structure is valence-precise in the reduced halide part, but electron-deficient in the intermetallic part. Susceptibility and resistivity measurements reveal the metallic nature of the compounds.     

Preparation of Cellulose Oligomers from Cellulose Triacetate (Standard Procedure)

This communication reports the detailed procedure for the cleavage of cellulose triacetate (30 g scale) with pivalic anhydride and boron trifluoride etherate in dichloromethane (pivaloylysis). With this mild and efficient method the cellulose oligomers up to the octasaccharide can be obtained in gram scale. Full characteristic data of this compounds are given.