Zur Anionkatalyse der Autoxydation

Zusammenfassung Soweit im Sinne des kürzlich entwickelten Autoxydations-mechanismus es ein Anion ist, das sein Elektron an das O₂-Molekül unter gleichzeitiger Anlagerung überträgt, liegt als Bruttoergebnis Katalyse der Autoxydation seitens des betreffenden Anions vor; an Hand einer Reihe von (einwertigen) Anionen wird diese Anionkatalyse diskutiert.     

Green chemistry approaches to the synthesis of 5-alkoxycarbonyl-4-aryl-3,4- dihydropyrimidin-2(1H)-ones by a three-component coupling of one-pot condensation reaction: comparison of ethanol,water, and solvent-free conditions

A general and practical green chemistry route to the Biginelli cyclocondensation reaction using cerium(III) chloride as the catalyst (25% mol) is described under three different sets of reaction conditions. This method provides an efficient and much improved modification of original Biginelli reaction reported in 1893, in terms of high yields, short reaction times, and simple work-up procedure, and it has the ability to tolerate a wide variety of substitutions in all three components, which is lacking in existing procedures.     

Balanced incomplete block designs with block size 8

The necessary conditions for the existence of a balanced incomplete block design on υ ≥ k points, with index λ and block size k, are that: For k = 8, these conditions are known to be sufficient when λ = 1, with 38 possible exceptions, the largest of which is υ = 3,753. For these 38 values of υ, we show (υ, 8, λ ) BIBDs exist whenever λ > 1 for all but five possible values of υ, the largest of which is υ = 1,177, and these five υ's are the only values for which more than one value of λ is open. For λ>1, we show the necessary conditions are sufficient with the definite exception of two further values of υ, and the possible exception of 7 further values of υ, the largest of which is υ=589. In particular, we show the necessary conditions are sufficient for all λ> 5 and for λ = 4 when υ ≠ 22. We also look at (8, λ) GDDs of type 7^m. Our grouplet divisible design construction is also refined, and we construct and exploit α ‐ frames in constructing several other BIBDs. In addition, we give a PBD basis result for {n: n ≡ 0, 1; mod 8, n ≥ 8}, and construct a few new TDs with index > 1. © 2001 John Wiley & Sons, Inc. J Combin Designs 9: 233–268, 2001     

Zur Autoxydation von Ferroion

Ohne Zusammenfassung     

Complementary use of microanalysis by the direct observation of nuclear reactions and of backscattering induced by charged particles

Techniques are described which combine the use of nuclear reactions and of backscattering to obtain analytical results which would be difficult or impossible to reach using one of these methods only. The principles of stoichiometry determination by plateau height analysis are developed both for backscattering and for narrow resonances of nuclear reactions. Examples of applications are given to the determination of the composition of various thin films of aluminium and silicon oxides, silicon nitrides and calcium fluorides. The analysis of samples smaller than the beam, using backscattered particle monitoring, is presented. Work supported by the C.N.R.S. (RCP N^o 157), the D.R.M.E. and the D.G.R.S.T.     

Ein Hinweis,betreffend Cupriion-katalysierte Redoxreaktionen

Es wird nahegelegt, bei Diskussion experimenteller Ergebnisse betreffend Cupriion-katalysierte Redoxreaktionen auf eine bisher kaum in Betracht gezogene parallele Reaktionslinie Bedacht zu nehmen.

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63, Hamilton Terrace, London, N. W. 8.     

Oscillatory motion of a viscoelastic fluid past a stretching sheet

Summary The boundary layer flow of a viscoelastic fluid (Walters' B model) past a stretching sheet is considered for investigation. The solution of the equation of motion is obtained using the power series method. The effects of the viscoelastic parameterk ₁ on the flow have been investigated. It is also found that the effects of unsteadiness in the wall velocity and skin-friction are appreciable.     

Application of Mössbauer spectroscopy to physical metallurgy: The role of light interstitial elements

Hyperfine Interactions - Light elements like hydrogen, nitrogen, and carbon, residing on interstitial sites of the host lattice, are capable of inducing noticeable changes in the physical...     

Some new bibds with k = 6 and λ = 1

(v, 6,1) BIBDs are given for several new values of v. This reduces to 55 the number of v values for which existence of a (v,6,1) BIBD is in doubt. A new resolvable (565,5,1) BIBD is also given. © 1995 John Wiley & Sons, Inc.