Elastoplastic stability of sandwich plates with a light core

The elastoplastic stability of sandwich plates with a light core is theoretically investigated. Certain specific problems are considered.Tashkent Lenin State University. Translated from Mekhanika Polimerov, No. 3, pp. 568–571, May–June, 1971.     

Certain Transformations of Anabasine and Nicotine

Electrocatalytic reduction of the alkaloids anabasine and nicotine was investigated. 1-,-Dipiperidyl and hexahydronicotine were prepared. The reactions of anabasine and the hydrogenated alkaloids with dicarboxylic acid anhydrides were studied.     

The Dirichlet Problem for H-Systems with Small Boundary Data: BlowUp Phenomena and Nonexistence Results

Given H:ℝ³→ℝ of class C¹ and bounded, we consider a sequence (uⁿ) of solutions of the H-system in the unit open disc satisfying the boundary condition uⁿ=γⁿ on ∂. In the first part of this paper, assuming that (uⁿ) is bounded in H¹(,ℝ³) we study the behavior of (uⁿ) when the boundary data γⁿ shrink to zero. We show that either uⁿ→0 strongly in H¹(,ℝ³) or uⁿ blows up at least one H-bubble ω, namely a nonconstant, conformal solution of the H-system on ℝ². Under additional assumptions on H, we can obtain more precise information on the blow up. In the second part of this paper we investigate the multiplicity of solutions for the Dirichlet problem on the disc with small boundary datum. We detect a family of nonconstant functions H (even close to a nonzero constant in any reasonable topology) for which the Dirichlet problem cannot admit a ``large' solution at a mountain pass level when the boundary datum is small.     

Variational inequalities for the spectral fractional Laplacian

In this paper we study obstacle problems for the Navier (spectral) fractional Laplacian (?Δ_Ω) ^s of order s ∈ (0,1) in a bounded domain Ω ? R ⁿ .     

Nickel(II) Complexes of Novel P,N-Heterocycles Based on Pyridylphosphines

Abstract

Novel 1,5-diaza-3,7-diphosphacyclooctanes were synthesized by Mannich-type condensation of pyridylphosphine, formaldehyde, and primary amines. Their interaction with Ni(II) salts containing different counterions was studied.     

Synthesis of Bis(2-Pyridylphosphino)Alkanes in Superbasic Medium and Their Hydroxymethyl Derivatives

Abstract

Novel P-H-diphosphinoalkanes with pyridyl substituents at the phosphorus atoms have been obtained in good or moderate yields by the interaction of primary 2-pyridyl-phosphine with dichloroalkanes in superbasic medium. The formation of novel 1-(2-pyridyl)-1-phosphacyclopentane together with bis(2-pyridylphosphino)butane was observed as the result of the interaction of 2-pyridylphosphine and 1,4-dichlorobutane under the same reaction conditions. The reaction of the bis(2-pyridylphosphino)alkanes thus obtained with formaldehyde leads to the formation of the corresponding hydroxymethyl derivatives.     

A one-step method for producing microencapsulated phase change materials

This short communication reports our recent work on the synthesis and characterisation ofmicrocapsules of phase change materials using silica as the shell material through a one-step method. The method uses no surfactants or dispersants for stabilising the capsules. The results show that the one-step method allows the tuning of the size and polydispersity of the capsules, and the use of different core materials. Analyses of the capsules show that they contain about 65% phase change materials. The results also suggest no need for a stabilising agent due to self-stabilisation by the amine groups. Further work is underway to investigate the mechanical and thermal properties of the microcapsules and the scale-up of the method.