Interferences and Methods for Their Elimination in the Determination of Lanthanum as LaO by Laser-Enhanced Molecular Flame Ionization Spectrometry

Interfering effects of some elements on the determination of lanthanum as LaO in a natural gas–air flame by laser-enhanced molecular ionization spectrometry were studied. It was demonstrated that easily ionized elements (Li, K, Na, Mg) exert an ionization effect; in addition, sodium introduces spectral interference. Techniques were proposed for the elimination of these interfering effects.     

Quantum Mechanical Equivalence of the Metrics of a Centrally Symmetric Gravitational Field

Theoretical and Mathematical Physics - We analyze the quantum mechanical equivalence of the metrics of a centrally symmetric uncharged gravitational field. We consider the static Schwarzschild...     

Plastic flow instability: Chernov–Lüders bands and the Portevin—Le Chatelier effect

We have studied the regularities in the evolution of macroscopic nonuniformities in the plastic flow of metals in the form of the Chernov–Lüders bands and the Portevin—Le Chatelier effect. The regularities in the evolution of strain inhomogeneity in these two cases have been established, and the kinetics of motion of the Chernov–Lüders fronts and abrupt deformation in the Portevin–Le Chatelier effect has been analyzed. It has been shown that the Chernov–Lüders fronts and Portevin–Le Chatelier jumpwise straining can be treated as macroscopic autowave processes of switching and excitation, respectively, in deformed media of various origins.     

Switching Autowaves in Materials with Dislocations and Martensitic Transformations

Russian Physics Journal - The paper focuses on the investigation of the strain kinetics at the yield point of materials with shear dislocations and martensitic transformations at a microlevel. In...     

Laser-enhanced molecular-ionization spectrometry of BaO and LuO in low-temperature flame

The molecular ionization spectra of BaO and LuO were recorded in low-temperature natural gas-air flame with excitation laser wavelengths in the range 440–480 and 535–575 nm. Addition excitation of barium and lutetium monoxides by a second laser quantum did not amplify the ionization signal. One-step laser excitation with wavelengths of 549.3 and 466.2 nm is optimal for BaO and LuO, respectively.     

Aspect-ratio dependent oscillatory thermocapillary convection in the floating half zone

The dependency of the critical Marangoni number on the geometrical aspect ratio of the floating half zone is essential to predict the onset of oscillatory thermocapillary convection.The experimental studies in the microgravity conditions on floating half zones of several centimeters in diameter have predicted that the critical Marangoni number increases with the increasing aspect ratio,and the terrestrial experimental studies have predicted the contradictory conclusion for floating half zones of several mil...