Role of packing-defect energy in the localization of plastic strain during shock-wave loading of copper-based solid solutions

The formation of deformation structure accompanying a change in the packing-defect energy (PDE) and the conditions of deformation of copper-based solid solutions under shock-wave loading were investigated by the method of optical microscopy. It is shown that in the case of solid solutions with high PDE plastic strain is localized. This localization increases with the amplitude and duration of the shock pulse, and this in turn gives rise to the generation and growth of microcracks. V. D. Kuznetsov Siberian Physicotechnical Institute at Tomsk State University. Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Fizika, No. 2, pp. 30–34, February, 1993.     

Chemiluminescent emission of CH*, C*<Subscript>2</Subscript>, OH*, and CO*<Subscript>2</Subscript> during the ignition of ethane behind reflected shock waves

The chemiluminescent emission from CH*, C*₂, OH*, and CO*₂ during the self-ignition of various mixtures of ethane with oxygen and argon behind reflected shock waves in the 1240–1790 K temperature range at a total concentration of the mixture М ₅ = (1 ± 0.2) × 10^?5 mol/cm³ is experimentally studied. It has been shown that the time-to-maximum in the emission intensity profiles is almost identical for all the emitters studied. How the pattern of the OH* emission profile changes with the temperature and mixture composition is examined. The CH* and C*₂ emission profiles demonstrate virtually symbatic behavior in the covered ranges of temperature, pressure, and equivalence ratio. It is established that the emission signals from OH* and CO*₂ appear earlier than the C*₂ and CH* emission signals. The numerical simulation predictions are found to be in close agreement with the experimental results.     

Dielectric and optical properties of gadolinium doped bismuth ferrite

Polycrystalline samples of a Gd _x Bi_1?x FeO₃ system are prepared by a conventional ceramic technology. Temperature and frequency dependences of a component of permittivity in the range of radio- and ultra-high frequencies are investigated. Features of the behavior of the reflectance spectra and spectra of the components of the dielectric and optical functions in the region of lattice and electronic resonances are investigated.     

Hyper-Cross-Linked Polystyrene as a Stabilizing Medium for Small Metal Clusters

Among different polymers nanostructured cross-linked aromatics have the greatest potential as catalytic supports due to their exceptional thermal and chemical stability and preservation of the active phase morphology. This work studies the ability of hyper-cross-linked polystyrene (HPS) to stabilize small Pd_n and Pt_n (n = 4 or 9) clusters. Unrestricted DFT calculations were carried out for benzene (BZ) adsorption at the BP level of theory using triple-zeta basis sets. The adsorption of BZ rings (stepwise from one to four) was found to result in noticeable gain in energy and stabilization of resulting adsorption complexes. Moreover, the interaction of metal clusters with HPS micropores was also addressed. For the first time, the incorporation of small clusters in the HPS structure was shown to influences its geometry resulting in the stabilization of polymer due to its partial relaxation.     

Spectral-kinetic characteristics of crystals and nanoceramics based on BaF<Subscript>2</Subscript> and BaF<Subscript>2</Subscript>: Ce

Optical characteristics of BaF₂ and BaF₂: Ce single crystals and nanoceramic materials prepared from these single crystals by uniaxial hot pressing have been studied. It has been shown that the introduction of Ce₃₊ ions into BaF₂ hardly affects the ultrafast (∼0.9 ns) luminescence component. The integrated luminescence intensity of the BaF₂: Ce nanoceramics is higher than that of the corresponding single crystal and considerably higher that the intensity of the undoped BaF₂ crystal. It has been demonstrated that the slow (several hundred nanoseconds) component of the luminescence decay of BaF₂: Ce is due to the energy transfer from excitons to Ce³⁺ ions.     

Magnetic properties of multiferroics Bi<Subscript>1 – <Emphasis Type="Italic">x</Emphasis></Subscript>Sm<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>FeO<Subscript>3</Subscript> synthesized under high pressure

The magnetic properties of the multiferroics obtained upon isovalent substitution of samarium cations for bismuth cations in BiFeO₃. The samples have been synthesized by solid-phase reactions under conditions of a cold pressing at high (4 GPa) pressure. The correlation between the structure and the magnetic properties of the multiferroics has been found based on analyzing the experimental data.     

Energy difference and energy of mixing for crystalline structures of Ni-Ti-Mo alloys

Using the locator variant of the coherent potential method combined with the canonicald band approximation, we have obtained the energy characteristics of molybdenum-containing titanium nickelide alloys for real and virtual high-symmetry crystalline phases. We have analyzed the reasons implied by the calculation results for the difference in the properties of molybdenum- and iron-containing alloys.V. D. Kuznetsov Siberian Physicotechnical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 43–48, June, 1995.     

Deuterium state and the possibility for cold nuclear synthesis in solids

We calculate the deuteron potential and the probability for cold nuclear synthesis for deuterium in the TiD₂ compound and its alloys with 3d-period elements. In the band model of a deuteron gas in a solid we examine the influence of the diffusion currents on the reaction rate. We show that by itself being in the solid state the Coulomb barrier for nuclear reactions is lowered in comparison with the deuterium gas. However, in a solid a necessary condition is the presence of physical processes and fields which lead to a nonequilibrium state for the deuterium subsystem.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 20–30, October, 1993.