On the uniform convergence of the Chebyshev interpolants for solitons

We discuss polynomial interpolation and derive sufficient conditions for the uniform convergence of Chebyshev interpolants for different classes of functions. Rigorous results are illustrated with a number of examples which include solitons on an infinite line with algebraic, exponential and Gaussian decay rates. Suitable mappings of the real line to the interval [−1,1]$[-1\text{,}1]$ are considered for each class of solutions.     

Mechanism of fracture of dispersion-strenghthened tungsten

Conclusions In a dispersion-strengthened tungsten alloy fracture mechanisms change with rise in temperature in the same sequence as in unalloyed tungsten: quasibrittle cleavage at low temperatures is succeeded by partly tough fracture at 400°C (T _Br ^u1 ), tough fracture through the body of the grain is observed in the range from 1000 (T _Br ^u2 ) to 1600°C, and at 1800°C tough intergranular fracture commences. The cold-brittleness points of the dispersion-strengthened tungsten alloy are lower (T _Br ^u1 by 100 and T _Br ^u1 by 200°C) then those of unalloyed tungsten, while the temperature of transition to tough intergranular fracture is higher. As a result, the dispersion-strengthened alloy has a wider temperature range of tough transgranular fracture, with a larger value of. The wider range of tough transgranular fracture in the dispersion-strengthened tungsten alloy may be linked with a tendency for microvoids to form in the material on the second-phase particles, as a consequence of which subsequent fracture occurs by a microvoid coalescence mechanism.Translated from Poroshkovaya Metallurgiya, No. 7(283), pp. 31–35, July, 1986.     

Mechanical properties of type IIb synthetic diamond at a temperature of 900°C

Mechanical properties of a type IIb synthetic diamond produced by the temperature gradient method have been studied at 900°C using indenters having different angles between the pyramid axis and face. The strain-strain curve has been constructed in the stress-total strain coordinates. It has been shown that in the diamond deformation the strain hardening with a linear dependence of flow stress on the plastic strain degree occurs. It has been found that the microhardness and fracture toughness of the tested synthetic diamond and natural diamond and the mechanism of their deformation do not differ essentially.     

Resistive Properties of the Sintered Ceramic Composite Si3N4 - SiC

A technology has been developed for activated sintering of resistive Si₃N₄ - SiC ceramic composite. The microstructure, electrophysical properties and strength of the materials obtained have beenstudied over a wide range of concentration.     

Increasing the stability of constant-speed hydromechanical systems

A method is proposed for increasing the stability of a constant-speed hydromechanical system developed for ground transportation. The method is based on a dynamic shock absorber in a centrifugal pendulum.     

Structure and electrophysical properties of hot-pressed ceramic materials in the Si3N4-SiC system. I. Structure formation and phase composition

Translated from Poroshkovaya Metallurgiya, No. 7(355), pp. 52–57, July, 1992.     

DFT Quantum-Chemical Calculation of Thermodynamic Parameters and DSC Measurement of Thermostability of Novel Benzofuroxan Derivatives Containing Triazidoisobutyl Fragments

New derivatives of benzofuroxan containing triazidoisobutyl fragments, opening the way for the creation of highly effective compositions with an increased value of energy characteristics, were synthesized for the first time. Such compounds are also an excellent platform for further modification and for the preparation of new biologically-active compounds containing tetrazole and triazole fragments. Calculations of heats of formation performed with the DFT (density functional theory) method showed that the studied compounds are high-energetic density ones, the enthalpies of formation of which are comparable to the enthalpies of formation of similar benzofuroxan derivatives and exceeds experimental enthalpy of formation of CL-14 (5,7-diamino-4,6-dinitrobenzofuroxan). The analysis of DSC indicates a sufficiently high thermal stability of the synthesized azidobenzofuroxans, which are acceptable for their use as components in the creation of highly efficient compositions with an increased value of energy characteristics.