Evolution of the phase composition and physicomechanical properties of ZrO<Subscript>2</Subscript> + 4 mol % Y<Subscript>2</Subscript>O<Subscript>3</Subscript> ceramics

The evolution of the phase composition and physicomechanical properties of ZrO₂ + 4 mol % Y₂O₃ ceramics subjected to hot isostatic pressing and subsequent calcining in air is investigated. It is found that hot isostatic pressing results in the formation of an easily transformed phase T_et with a degree of tetragonality c/a=1.035, which determines high fracture toughness. After calcining in air, the phase T_et decomposes to form a nontransformed phase T′ with a degree of tetragonality c/a=1.005, which determines low fracture toughness.     

Effect of the State of a Surface Layer on the Properties of Pd–P Catalysts in the Hydrogenation of Alkylanthraquinones

Kinetics and Catalysis - X-ray photoelectron spectroscopy (XPS) was used to study the state of the surface layer of a Pd–P catalyst, which exhibits high selectivity in the hydrogenation of...     

Femtosecond spectroscopy of coherent anti-Stokes Raman scattering with frequency-tunable chirped pulses generated in a microstructure fiber

A new scheme of chirped-pulse femtosecond coherent anti-Stokes Raman scattering spectroscopy is proposed and experimentally implemented. A theory of this modification of coherent nonlinear spectroscopy is developed. We use this approach to show that a linear time-frequency mapping defined by linearly chirped pulses allows the spectra of nonlinear response of a medium to be measured by varying the delay time between the pump pulses. Microstructure fibers with a special dispersion profile are at the heart of the experimental implementation of this technique. Such fibers are ideally suited for the generation of frequency-tunable pulses with a smooth envelope and a controlled chirp. We present the results of experimental characterization of the envelope, spectrum, and chirp of anti-Stokes pulses generated in microstructure fibers by femtosecond Cr:forsterite-laser pulses. These frequency-tunable anti-Stokes pulses produced and shaped in microstructure fibers are then employed for coherent anti-Stokes Raman scattering spectroscopy of toluene solution.