Adsorption and Desorption of Water on Tin Dioxide

Adsorption isotherms were obtained for water on SnO₂ samples subjected to heat treatment at various temperatures. The monolayer capacity and adsorption constants were determined by Langmuir equation. The enthalpy and entropy of adsorption were determined using the isobar equation.     

Diastereoselective hydrogenation of α,β-dehydrodipeptides bearing unsaturatedN-terminal amino acids and of ther complexes with CaCl2 and MgCl2

The formation of complexes of dehydrodipeptides bearingN-terminalN-benzoyl-O-methyl-α,β-dehydrotyrosine orN-benzoyl-α,β-dehydrovaline residues with Ca²⁺ and Mg²⁺ ions enhances the diastereoselectivity of their hydrogenation;de of 66% and 80% were achieved. This method of increasing the stereoselectivity of hydrogenation is applicable to various dehydroamino acids at both theC- andN-termini of dehydrodipeptides. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 345–347, February, 1997.     

On the order of partial sums of general orthogonal series

It is shown that for convergence of every orthonormal system _n(x) given on [0, l],it is necessary and sufficient that, under the condition on tlie increasing function W(x) and for there hold almost everywhere on [0, 1].Translated from Matematicheskie Zametki, Vol. 6, No. 4, pp. 451–462, October, 1969.