Zur Untersuchung der Kalisalze und zur Bestimmung des Kalis

Ohne Zusammenfassung     

Saddlepoint approximations for multivariate <Emphasis Type="Italic">M</Emphasis>-estimates with applications to bootstrap accuracy

We obtain marginal tail area approximations for the one-dimensional test statistic based on the appropriate component of the M-estimate for both standardized and Studentized versions which are needed for tests and confidence intervals. The result is proved under conditions which allow the application to finite sample situations such as the bootstrap and involves a careful discretization with saddlepoints being used for each neighbourhood. These results are used to obtain second-order relative error results on the accuracy of the Studentized and the tilted bootstrap. The tail area approximations are applied to a Poisson regression model and shown to have very good accuracy. An erratum to this article can be found at     

Stacking pattern of multi-layer InAs quantum wires embedded in In0.53Ga0.47−xAlxAs matrix layers grown lattice-matched on InP substrate

Multi-layer InAs quantum wires were grown on, and embedded in In_0.53Ga_0.47−xAl_xAs (with x=0, 0.1, 0.3 and 0.48) barrier/spacer layers lattice matched to an InP substrate. Correlated stacking of the quantum wire arrays were observed with aluminum content of 0 and 0.1. The quantum wire stacks became anti-correlated as the aluminum content was increased to 0.3 and 0.48. The origin of such stacking pattern variation was investigated by finite element calculations of the chemical potential distribution for indium on the growth front surface of the capping spacer layer. It is shown that the stacking pattern transition is determined by the combined effect of strain and surface morphology on the growth front of the spacer layers.     

A neo-pentyl-ferrocene motif for the synthesis of electroactive polyesters

Several new neo-pentylenediol based ferrocenyl molecules have been prepared using Friedel-Crafts acylation and Clemmensen reduction techniques. The acyl or methyl linker by which the ferrocenyl group is attached tunes the redox properties of the small molecule. The X-ray crystal structure of the acylferrocene with protecting ester groups, its derivative dialcohol, and the methylferrocene dialcohol compounds are reported. Melt polymerisation conditions result in an elimination from the acyl monomer, but a mild carbodiimide coupling protocol successfully generates a number of neo-pentylenediol/aromatic dicarboxylate polyesters with pendant ferrocenyl groups.     

Potentiometrie

Ohne Zusammenfassung     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

Study of interference in the flame atomic absorption spectrometric determination of lithium by using factorial design

The severe interference of a number of metallic ions found in brines, marine sediments and sea water in the determination of lithium is demonstrated. Calcium, iron and sodium significantly depressed the absorption signal on lithium in an air/acetylene flame. Aluminium, magnesium and strontium up to 1500, 1000 and 200 μg/mL, respectively, showed no interference in the determination of lithium under the same conditions. Potassium produced some suppression of the lithium signal at levels in excess of 1500 μg/mL. Experimental data were examined using the factorial design method. Interference was demonstrated in two synthetic samples (models of “brine” and “marine sediments” ) and natural marine sediment. It was possible to eliminate all interferences using a higher temperature (nitrous oxide/acetylene flame). In addition, by using the standard addition method the interference disappeared, which confirmed the interference as a proportional systematic error.