Comment on bounds on time-correlation functions via the infinite-order maclaurin expansion

The method recently proposed by Alien and Diestler for obtaining bounds to time-autocorrelation functions is not (as claimed by the authors) equivalent to the method of Platz and Gordon, nor does it provide bounds at all times. It is instead equivalent to the method of Cukier and Wheeler based on gaussian quadratures. The quadratures are preferable to the approximate summation of the Maclaurin series.     

A study of retention characteristics by functional group analysis using supercritical fluid chromatography

Summary Supercritical fluid chromatography (SFC) has recently been applied to the analysis of agricultural compounds. Studies investigating factors governing retention behavior of the compounds of interest will facilitate SFC method development for new compounds and metabolites. In this study, several compounds containing various functional groups were examined. Initial trends in retention were established; where appropriate, retention behavior was correlated with functional group similarities, differences and regio chemistry of compounds containing the same functional groups. Packed and capillary column SFC were used in these analyses. Results were compared to retention behavior observed under reversed-phase HPLC conditions. In general, the normal phase characteristics of SFC are very desirable in the separation of more polar compounds and metabolites of the agricultural products. Regio chemical effects and additions of methyl, phenyl, nitro, amide, carboxamide, chloro and other functional groups to common base molecules are discussed.

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Untersuchung des Retentionsverhaltens durch Analyse funktioneller Gruppen mit Hilfe der Chromatographie mit überkritischen fluiden Phasen

     

Meso-[2.2]paracyclophanyltriphenylporphyrin: A simple representative of cyclophanylporphyrins

(R + S)Meso-[2.2]Paracyclophanyltriphenylporphyrin 3 , a member of a novel class of cyclophanylporphyrins, was obtained and characterized by spectroscopic and electrochemical methods. Compared to meso-tetra[2.2]paracyclophanylporphyrin 1, it represents a simplified structure designed for the investigation of electronic interactions between the [2.2]paracyclophane moiety and porphyrin core and for use in metallation reactions.     

Stress bounds for the torsion of tubes of uniform wall thickness

Upper and lower bounds are derived for the torsional rigidity and the maximum shear-stress magnitude. The values provided by Bredt's formulas are characterized as asymptotic approximations. Explicit results on error bounds are included.     

Computer store enhancement by interchange

A new way of using random-access stores of differing speeds in a computer is given. It is effective when the fast and slow stores are of comparable size     

Potential-directed assembly of aryl iodonium salts onto silicon {100} hydride terminated and platinum surfaces

A novel electrograft method of forming covalent bonds directly to silicon hydride or platinum surfaces has been demonstrated with the use of iodonium salt precursors. Initially, a silicon substrate is treated with a dilute hydrofluoric acid wash to ensure a hydride-passivated surface, which is immersed in a solution of iodonium salt dissolved in a solution of tetrabutylammonium tetrafluoroborate in acetonitrile. Grafting is accomplished by applying a negative bias to the silicon substrate. Directed assembly has been demonstrated with Pt substrates.     

On wave propagation and uniqueness in one-dimensional elastic bodies

A notion referred to as the Wave Propagation Property is analyzed in the context of the nonlinear theory of one-dimensional elastic bodies. Roughly speaking, a body possesses this property if mechanical disturbances propagate with bounded speed. A uniqueness theorem is proven with the aid of the results on wave propagation.

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Zusammenfassung Ein Begriff, bezeichnet als Wellenfortpflanzungseigenschaft, wird in Zusammenhang mit der nicht-linearen Theorie des eindimensionalen elastischen Körpers untersucht. Ein Körper besitzt, gross gesprochen, diese Eigenschaft, wenn sich mechanische Störungen mit beschränkter Geschwindigkeit fortpflanzen. Mit Hilfe des Ergebnisses für Wellenfortpflanzung wird ein Eindeutigkeitsatz bewiesen.

     

Eine Untersuchung der strukturellen Ordnung in verschiedenen Polyäthylenen bei erhöhten Temperaturen

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