Mathematical analysis of a simple model for the stripping reaction

Zusammenfassung Die Integralgleichung (1.6), die aus einem sehr vereinfachten Modell der stripping reaction hergeleitet ist, wird diskutiert. Es ist bemerkenswert, dass die bekannte Methode vonN. Wiener undE. Hopf auf diese komplizierte Integralgleichung angewendet werden kann. Die entstehende Funktionalgleichung (1.12) wird im § 2 auf die lösbare Differenzengleichung (2.20) reduziert. § 3 behandelt die Eindeutigkeit der Lösung und § 4 die explizite Lösung in einem Spezialfall. Die explizite Lösung des allgemeinen Falls wird nicht angegeben.

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Most of the content of this paper grew out of discussions, which the author had withJ. H. D. Jensen, J. M. Luttinger, andT. H. Berlin during their respective stays at the Institute for Advanced Study. The author's only merit consists in having written down the results.

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Institute for Advanced Study.     

Papain Catalyzed Oligomerization of α-Amino Acids. Synthesis and characterization of water-insoluble oligomers of L-methionine

Water-insoluble oligomers were synthesized from L -methionine ethyl ester with papain as the catalyst. L -Oligomethionine was obtained in yields of 50% when synthesis was carried out in highly concentrated citrate buffer at pH 5.5. Yields of up to 85% were obtained when the enzymatic synthesis proceeded in distilled water at pH 6.5, the pH being strictly maintained. The insoluble polymer was converted to highly water-soluble sulfoxide and sulfone derivatives, which consist mainly of an octamer with low amounts of heptamer or hexamer. Most of the carboxyl terminals still contained the ethyl ester group, only a minor part being present in the free acid form. The potential of the enzymatic approach for the synthesis of optically pure and monodisperse oligomers of α-amino acids is discussed.     

Geometrische Methoden zur Gewinnung von A-Priori-Schranken für harmonische Abbildungen

In this paper, we prove a-priori estimates for harmonic mappings between Riemannian manifolds which solve a Dirichlet problem. These estimates employ geometrical methods and depend only on geometric quantities, namely curvature bounds, injectivity radii, and dimensions. An essential tool is the introduction of almost linear functions on Riemannian manifolds. Furthermore, we show the existence of almost linear and harmonic coordinates on fixed (curvature controlled) balls. These coordinates possess better regularity properties than Riemannian normal coordinates.

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Die Autoren wurden bei der Anfertigung dieser Arbeit von den Sonderforschungsbereichen 72 und 40 der Universität Bonn unterstützt     

Synthese und einige biologische Aktivitäten von Deamino-Vasopressin-Analogen mit der zu einer Thioätherbrücke umgewandelten Disulfidbrüeke

Ohne Zusammenfassung     

Über Pterinchemie. 64. Mitteilung. Die Kristallstruktur von 6-Methyl-7,8-dihydropterin-monohydrochlorid-monohydrat

The crystal structure of 6-methyl-7,8-dihydropterine-monohydrochloride-monohydrate The crystal structure of the title compound has been determined by X-ray analysis (direct methods) and refined with 990 structure amplitudes to R = 0.025. The crystal system is triclinic, space group P1 , with unit cell dimensions a = 5.859, b = 7.686, c = 12.107, α = 71.84, β = 76.35, γ = 85.80. The molecule is protonated at the N(5)-position and is planar. The atoms H(19) and H(20) are with 0.818 Å above respectively with ?0.705 Å under the plane.     

Laudatio to the 60th birthday of Rudolf Haag

Ohne Zusammenfassung

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Laudatio to the 60th birthday of Rudolf Haag