Creep of composites with a porous fibre/matrix interface under variable loading

A micromechanical model of island-type fibre/matrix interface is described and experimental data are represented and analysed. Changes in the interface strength during a cycle loadings and, correspondingly, changes in the creep resistance of a composite due the island-like scheme of the fibre/matrix interface are described.     

Lattice Dynamics in LaTa2-2xNb2xVO9-δ (x=0–0.1) Solid Solutions

The oxygen nonstoichiometry (x) of LaTa_2-2xNb_2xVO₉- (x = 0–0.1) solid solutions was studied using Xray phase analysis, vibrational spectroscopy, and radiospectroscopy. A correlation was found between (x) and the unit cell volume V(x) of the solid solutions. It was shown that the infrared spectra of LaTa₂VO₉- change in passing from = 0 to 0. The structural position of the oxygen vacancy in LaTa_2-2xNb_2xVO₉- is discussed.     

Strain-gauge study of the strain state for the structural elements of the Moscow University main building’s spire

The experimental and numerical study of the strain state is conducted for the spire of the Moscow University main building. The experimental data are in good agreement with the numerical results obtained according to a finite-element beam model of the spire.     

The compression of a thin strip of material in a superplasticity state

The viscoplastic flow of a thin strip of material in a superplasticity state between rigid, converging parallel planes (an analogue of Prandtl's problem) is investigated. An analytical quadrature solution of the problem is constructed, asymptotically precise in the same sense as Prandtl's solution. Special cases are considered where the solution (including an approximate solution) is written out fully. The effects of superplasticity are determined.     

Flutter of a viscoelastic strip

The unsteady panel flutter of a viscoelastic strip is studied under the conditions when the pressure of aerodynamic interaction is specified by the relations distinct from the piston theory formulas. It is assumed that the flow velocity vector is directed in parallel to the plate plane at an angle to its edges. Some approximate estimates of the critical flutter speed are obtained.     

Trihaloacetate-Selective Electrodes Based on Hexyl p-Trifluoroacetylbenzoate

Analytical properties of trihaloacetate-selective film electrodes with membranes containing hexyl p-trifluoroacetylbenxoate as a solvating agent were studied. The use of trichloroacetate-selective electrodes for the determination of trichloroacetic acid and its salts in medical diagnostic kits was shown in examples.     

Intrinsic point defects and electron-energetic characteristics of hexagonal monoxide of beryllium

Using the zone method of a linear combination of plane waves for the supercell model, there have been studied energy and electron states of beryllium monoxide BeO with intrinsic point defects: the vacancy in the sub-lattice of beryllium + interstitial atom of Be {V_Be + Be_i}. The most stable among the considered configurations of defects are the vacancies and interstitial atoms of beryllium Be _i ^o occupying octahedral positions at R(V_Be-Be _i ^o ) ～ 3.15–3.35 Å distances from each other. Depending on the configuration of defects, the forbidden gap of beryllium oxide can change by ～0.4–2.4eV.     

Similarity parameters and simulation of plate vibrations in a supersonic gas flow

A number of rules are proposed to convert the parameters characterizing the plate vibrations in a model experiment to the corresponding parameters in a full-scale process (or in another experiment). The plate material is orthotropic and viscoelastic. The flutter model is based on the piston theory or on the linearized theory of supersonic potential flow.     

Flow of a plastically anisotropic layer between parallel planes in a region with a sink

A self-similar solution to the problem of flow of a plastically anisotropic layer between parallel planes in a region with a sink is constructed. The problem can be reduced to solving an unstudied Riccati equation with a small parameter. The perturbation method is used to find two different solutions expressed in terms of quadratures.