Untersuchung von Harn, Blut und sonstigem biologischen Material

Ohne Zusammenfassung     

The BRS method and geometric quantization: Some examples

We recall the method of quantization of constraints as outlined by kostant and Sternberg. We discuss various examples to test compatibility between geometric quantization and this procedure. In almost all cases reduction and quantization commute.Supported by the Dutch organization for Scientific Research (NWO)Unité Propre de Recherche 7061, CNRS     

Iterated homology and decompositions of simplicial complexes

Kalai has conjectured that a simplicial complex can be partitioned into Boolean algebras at least as roughly, as a shifting-preserving collapse sequence of its algebraically shifted complex. In particular, then, a simplicial complex could (conjecturally) be partitioned into Boolean intervals whose sizes are indexed by its iterated Betti numbers, a generalization of ordinary homology Betti numbers. This would imply a long-standing conjecture made (separately) by Garsia and Stanley concerning partitions of Cohen-Macaulay complexes into Boolean intervals. We prove a relaxation of Kalai’s conjecture, showing that a simplicial complex can be partitioned into recursively defined spanning trees of Boolean intervals indexed by its iterated Betti numbers.     

Sur la thermogravimétrie des précipités analytiques : Dosage du sodium

This thermogravimetric study has enabled the authors to specify a large number of points of detail in connection with the correct determination of sodium. Their attention has been particularly directed to the triple acetates, which they recommend should be weighed only in the form of pyro-uranates. The method of ball, less classical than the others, would merit greater attention on the part of analysts.     

Semi-micro dosages gravimétrique et volumétrique de la silice

The author furnishes results checked by three years of practice, concerning the measurment of traces of silica.This is transformed into a complex silicomolybdate by means of hexamethylenetetramine Treated with special in precautions the Precipitate yields a residue of SiO₂ + 12MoO₃ ,weighing about tlurty times more than the starting silica.Since the titration of the hexamethylenetetramine used can be done by means of iodine, we have here a means of titrating the silica used after destroying hydrolytically the preipitaite of silicomolybdateThese methods have so far been applied only to solutions containing free silica or alkilisilicates.     

Ueber die Natur der Fermente

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Synthesis of 6-amino-5-cyano-1,4-disubstituted-2(1H)-pyrimidinones via copper-(I)-catalyzed alkyne-azide 'click chemistry' and their reactivity

In this paper we present the room temperature synthesis of a novel serie of 1,4-disubstituted-1,2,3-triazoles 4a-l by employing the (3+2) cycloaddition reaction of pyrimidinones containing alkyne functions with different model azides in the presence of copper sulphate and sodium ascorbate. To obtain the final triazoles, we also synthesized the major precursors 6-amino-5-cyano-1,4-disubstituted-2(1H)-pyrimidinones 3a-r from ethyl 2,2-dicyanovinylcarbamate derivatives 2a-c and various primary aromatic amines containing an alkyne group. The triazoles were prepared in good to very good yields.     

Dispersion and localization of electronic states at a ferrocene/Cu(111) interface

Low-temperature scanning tunneling microscopy and spectroscopy combined with first-principles simulations reveal a nondissociative physisorption of ferrocene molecules on a Cu(111) surface, giving rise to ordered molecular layers. At the interface, a 2D-like electronic band is found, which shows an identical dispersion as the Cu(111) Shockley surface-state band. Subsequent deposition of Cu atoms forms charged organometallic compounds that localize interface-state electrons.     

Rotation reversal bifurcation and energy confinement saturation in tokamak Ohmic L-mode plasmas

Direction reversals of intrinsic toroidal rotation have been observed in diverted Alcator C-Mod Ohmic L-mode plasmas following electron density ramps. For low density discharges, the core rotation is directed cocurrent, and reverses to countercurrent following an increase in the density above a certain threshold. Such reversals occur together with a decrease in density fluctuations with 2 cm(-1)≤k(θ)≤11 cm(-1) and frequencies above 70 kHz. There is a strong correlation between the reversal density and the density at which the Ohmic L-mode energy confinement changes from the linear to the saturated regime.