LiGeTe2, das erste kettenhypotelluridogermanat

The new compound LiGeTe₂ crystallizes in the triclinic system (space group PI) with the lattice constants: a = 725.5(3) pm, b = 913.2(4) pm, c = 1134.0(4) pmα = 75.75(5)°, β = 77.11(5)°, γ = 70.77(5)°. Octahedral Ge₂Te₆ - units are connected by common edges in such a way, that sixmembered Ge₄Te₂ - and fivemembered Ge₃Te₂ - rings form infinite strings.     

A local convergence analysis for the Gauss-Newton and Levenberg-Morrison-Marquardt Algorithms

Several orthogonal-invariant fixpoint theorems for the convergence of the Gauss-Newton Method are given which reduce to well-known Newton-Attraction theorems in case of a system of nonlinear equations. Subsequently this result is extended to the Levenberg-Morrison-Marquardt Algorithm.     

Multilevel failure detection system

A fuzy multilevel failure detection system is developed for complex processes with ill-known mathematical model and poor measuring accuracy. The decomposition of the problem is made with the aid of fuzzy switches and diagnostic algorithms which are specified by a set of conditional statements. The diagnosis system is demonstrated by a real low density polyethylene reactor in full detail.     

Doping modulation by electric currents in lithium niobate during crystal growth

The segregation coefficient of impurities being effective during crystal growth of LiNbO₃ from the melt can be influenced by electric currents through the growing interface. Examples are given for chromium dopings where the changes in concentration can easily be measured by optical methods. The effect can be used to mark the growing interface, to superimpose time markers during growth, and to generate periodic and aperiodic doping structures. Indications are given that the effect is due rather to electrochemical processes at the interface than to a change in growth rate caused by the Peltier effect.     

Die Bodenkörper des Systems Chrom(III)-Arsenat

Zusammenfassung Chrom(III)-orthoarsenat besitzt als Fixierungs-form des mykozid und insektizid wirksamen Arsenats im Holzschutz eine gro?e Bedeutung. Es werden die Darstellung, Entstehungsbedingungen, Zusammensetzung und L?slichkeitseigenschaften eines grauvioletten und des grünen Chrom(III)-orthoarsenats beschrieben und Angaben über das Verhalten des grünen Chromarsenats gegenüber terti?rem und sekund?rem Natriumarsenat sowie Arsens?ure gemacht. Vortrag, gehalten auf der 4. Holzschutztagung der Deutschen Gesellschaft für Holzforschung am 5. Juni 1954 in Berlin.     

Ray-casting and block model conversion using a spatial index

A spatial index is a data structure designed to facilitate spatial search, exemplified by the point-in-polyhedron inclusion problem. The 3D extensible cell (EXCELL) index is presented together with algorithms for spatial search and for converting a complex polyhedron (boundary representation) into an octree-like block model. We illustrate the techniques by an application to geometric mine modelling and demonstrate the efficiency of the approach by practical experiments.     

Measurement of the intramolecular fluctuations of random coil polymers by photon correlation spectroscopy

The correlation function of light scattered from dilute solutions of large molecular weight polystyrene has been measured using a photon-counting digital autocorrelator. By determining the effective spectral broadening and the change in the spectral profile due to intramolecular fluctuations, the range of validity of the Zimm-Rouse model of intramolecular dynamics has been examined.