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Thermal analyses of coordination compounds

II. Thermal decomposition of palladium complexes with triphenylphosphine, triphenylarsine and triphenylstibine

Journal of Thermal Analysis and Calorimetry
Authors: R. Barbiéri, C. Belatto, and A. Massabni

Abstract  

The compounds [PdCl2L2] and [PdL4] (L=PPh3, AsPh3, SbP3) were studied by thermogra-vimetric and differential thermal analyses in air. The residues of thermal decomposition consist of metallic palladium, except in the case of the complexes containing SbPh3, when the residues are palladium and antimony mixtures in appropriate proportions with respect to the stoichiometry of the related complexes.

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We investigate various aspects of stochastic integration in finite von Neumann algebras. For integration with respect to a bounded L 2 -martingale the idea of treating the integral as a bounded operator is developed. Several classes of integrable processes are defined, it turns out that some of them form a Banach or C *-algebra. We find representations of these algebras and establish relations between the von Neumann algebras generated by these representations. Finally, we characterize the range of the stochastic integration operator.

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Abstract  

We prove that the centered three-dimensional Wiener sausage can be strongly approximated by a one-dimensional Brownian motion running at a suitable time clock. The strong approximation gives all possible laws of iterated logarithm as well as the convergence in law in terms of process for the normalized Wiener sausage. The proof relies on Le Gall [10]șs fine L 2-norm estimates between the Wiener sausage and the Brownian intersection local times.

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Abstract

We consider the Dirichlet operator H t=−d 2/dx 2+q(x) on L 2([t,∞)), where q is a convex potential with q(x)→∞ as x→∞. We show that the eigenvalue gap Γ(t) of H t is monotone increasing as t increases from −∞ to ∞. We also show that Γ(t) is strictly increasing if q is not linear at infinity. An asymptotic estimate of Γ(t) for quadratic potentials is obtained.

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Summary This paper studies annihilating properties of operators generated by spherical convolution over the unit sphere O2q of Cq. Its specific aim is to answer the following question: given a complex number ?, |?|=1, to determine what functions of L 2(O2q) have zero average over every section  Ow ?,q  :={ z ?O2q: <z,w> = ?} of O2q . Here, <.,.>stands for the usual inner product of Cq.

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Hydroxylamine derivatives in Purex Process

I. Study on the kinetics of redox reaction between N,N-diethylhydroxylamine and nitrous acid

Journal of Radioanalytical and Nuclear Chemistry
Authors: Zhang Anyun, Hu Jingxin, Zhang Xianye, and Wang Fangding

Abstract  

The kinetics of oxidation-reduction reaction between N,N-diethylhydroxylamine (DEHAN) and nitrous acid in nitric acid solution have been studied by spectrophotometry at 9.5°C. The rate equation is −d[HNO2]/dt=K[HNO2]·[DEHAN][HNO3] and the rate constantK=12.81 (mol/l)−2·min−1. A possible mechanism has been suggested on the basis of chemical analysis and Raman spectra. The activation energyE and the thermodynamic functions ΔH #, ΔG # and ΔS # are also calculated.

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Extraction of microamounts of yttrium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of 15-crown-5 (15C5,L) has been investigated. The equilibrium data have been explained assuming that the complexes HL+, HL2, +, YL3+, YL2, 3+and YH-1L2, 2+are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

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Abstract

The adducts [CdX2(L-L)], where X = Cl, Br, I; L-L = 2,2’-bipyridine (bipy) or 2,2′-bipyridine N,N′-dioxide (bipyNO) have been synthesized and characterized by melting points, elemental analysis, thermal analysis, and IR spectroscopy. From calorimetric studies in solution, the standard enthalpies of formation of the adducts and several thermochemical parameters were determined. The mean standard enthalpies of the cadmium-nitrogen and cadmium-oxygen bonds have been estimated.

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Abstract  

When is the composition of paraproducts bounded? This is an important, and difficult question. We consider randomized variants of this question, finding nonclassical characterizations. For dyadic interval I, let h I = h I 0 be the L 2-normalized Haar function adapted to I, the superscript 0 denoting that it has integral zero. Set h I 1 = |h I|, the superscript 1 denoting a nonzero integral. A (classical dyadic) paraproduct with symbol b is one of the operators article image. Here, ɛ, δ ∈ {0, 1}, with one of the two being zero and the other one. We characterize when certain randomized compositions B(b, B(β, ·)) are bounded operators on L 2(ℝ), permitting in particular both paraproducts to be unbounded.

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Abstract  

All complexes of the series [MO2L2]+ (M=Tc, Re; L=ethylenediamine (en), 1,3-diaminopropane (1,3-dap)) have been synthesized and their chemical reactivities investigated. The following properties were studied: stability of the aqueous solutions at different pH values, substitution kinetics, lipophilicity and protein binding. The complexes show very similar reactivity in aqueous solution. From a radiopharmaceutical point of view, no significant difference in their in vivo behavior is expected.

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