Schallgeschwindigkeitsmessungen in Schmelzen aus den Systemen Al−Mg,Al−Sn,Mg−Sn und Fe−C

The concentration dependency of sound velocity was measured in molten alloys of the three systems Al–Mg, Al–Sn, and Mg–Sn in the temperature region between liquidus and 1000°C. Furthermore it was measured in molten alloys of the system Fe–C in the temperature range between liquidus temperatureT _L andT _L+150°C. From the velocities the compressibilities were calculated, whose concentration dependency revealed changes in the structure of the melts.The structure of the three systems Al–Mg, Al–Sn, and Mg–Sn in the molten state was already investigated by X-Ray diffraction. These results were compared with the results of velocity measurements. Inhomogeneities in the melts yield increased values of compressibility compared with the values to be expected for statistical distribution of the atoms. This result was used for the discussion of the structure of molten Fe-C-alloys:The conclusion can be drawn, that within the melts of the system Fe–C above 3^w/0 C inhomogeneities are existent.From the values of sound velocity in the molten elements the temperature dependency of the structure factorsI(0) was calculated and compared with experimental values.

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Teil der Dissertation von U. Maier, Universität Stuttgart, 1972.     

2-[6′-(O-trans-Cinnamoyl)-β-D-glucopyranosyloxy]-3-methyl 4H-pyran-4-one,a New Acylated Pyrone Glucoside from Silene vulgaris (Caryophyllaceae) Part 186. Papers on Organic Natural Products

A previously unreported acylated 4-pyroae glycoside, 2-[6'-(O-trans-cinnamoyl)β-D-glucopyranosyloxy]-3-methyl-4 H-pyran-4-one ( 1 ) has been isolated from the basic fraction of a chloroform/methanol extract of the shoots of Silene vulgaris (Moench) Garcke (Caryophyllaceae) and identified mainly on the basis of the spectral characteristics of this compound and its triacetate derivative as well as chemical degradation.     

High resolution auger electron spectroscopy for materials characterization

High resolution Auger microanalysis has become a widely applied technique in various fields of materials research. Its submicrometer spatial resolution is shown as being advantageous for surface, interface and thin film analysis. Limitations of the lateral resolution are outlined with respect to influences of electron backscattering, detection sensitivity, sample drift, beam heating and other electron induced processes. High in-depth resolution is linked with high spatial resolution for optimized depth profiling by sputtering. Crater edge profiling with scanning Auger microscopy is particularly useful for obtaining a three-dimensional microanalysis. Some examples demonstrate the capabilities and limitations in the analysis of precipitates, fracture surfaces and multilayer structures.