Analogs of pyrimidine nucleosides

N₁-(-Tetrahydrofuranyl)- and N₁-(-tetrahydropyranyl)uracils and the corresponding 6-azauracils have been obtained by the condensation of bistrimethylsilyl derivatives of uracils and 6-azauracils with-chlorotetrahydrofuran and-chlorotetrahydropyran. The superiority of the silyl method over the mercury method used previously has been demonstrated.For part III, see [9].     

Solution of one problem of nonlinear adsorption kinetics by the method of lines

The method of lines is constructed and proved for numerical solution of a nonlinear initial-boundary-value problem of parabolic type describing the adsorption of a substance from an aqueous solution of bounded volume by a spherical adsorbent. The method is developed under natural assumptions on the smoothness of the solution of the original problem. The rate of convergence of the method depends on the smoothness of the initial function and is of order O(h) if v₀(x) 0, O(h^1/2) if v₀(x) C¹[0, 1], and 0(|v ₀(x)|W ₂ ¹ (O,h)).Translated from Vychislitel'naya i Prikladnaya Matematika, No. 63, pp. 24–30, 1987.     

Elemental blood composition of the inhabitants of Uzbekistan

An instrumental neutron activation method for determining 17 elements in human whole blood of the inhabitants of Uzbekistan has been developed. 2790 blood samples were analyzed. Statistical processing of the results obtained has been done by computer. Mean concentration values have been calculated and plotted for the whole region. Correlation between the element contents and various parameters (sex, age, residence, ethnic group, working conditions, haemoglobin content, Rh, sampling time) has been found. This should be taken into account when studying various pathologies and the environmental impact on human health.     

Thermal decomposition of ethyl azidoformate in oleitns

Conclusions The mechanism for the thermolysis of ethyl azidoformate in olefins may be regulated by altering the reaction temperature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 226–228, January, 1986.     

Approximation of periodic functions by Steklov averages in <Emphasis Type="Italic">L</Emphasis><Subscript>2</Subscript>

In the space L₂ of periodic functions, we establish exact (in the sense of constants) estimates from below for the deviation of the Steklov functions of the first and second order in terms of the modulus of continuity of the second order. Similar results are also established for even continuous periodic functions with nonnegative Fourier coefficients in the space C. Bibliography: 5 titles. __________ Translated from Problemy Matematicheskogo Analiza, No. 35, 2007, pp. 79–90     

Influence of prestress on the velocities of plane waves propagating normally to the layers of nanocomposites

The paper is concerned with longitudinal and transverse waves propagating at a right angle to the layers of a nanocomposite material with initial (process-induced residual) stresses. The composite consists of alternating layers of two dissimilar materials. The materials are assumed nonlinearly elastic and described by the Murnaghan potential. For simulation of wave propagation, a problem is formulated within the framework of the three-dimensional linearized theory of elasticity for finite prestrains. It is established that the relative velocities of waves depend linearly on small prestresses. In some composite materials, however, the thicknesses of the layers may be in a ratio such that the wave velocities are independent of the prestress level __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 7, pp. 3–22, July 2006.