Modeling of non-equilibrium effects in silicon irradiated by pulsed laser

In this paper, we use the methods of mathematical modeling to investigate the action of laser pulse (picosecond) with a wave length of λL=0.53μm and the photon energy exceeding the band gap of silicon ħω>Eg on silicon target. The main feature of these regimes of laser irradiation is strong non-equilibrium of heating and melting processes, which is manifested in a large temperature difference between the carriers and the lattice

Nanosecond Laser Ablation: Mathematical Models, Computational Algorithms, Modeling

The basic mathematical models, computational algorithms, and results of mathematical modeling of various modes of laser action on metals are considered. It is shown that for mathematical description and analysis of the processes of laser heating, melting, and evaporation of condensed media, various theoretical approaches are used: continuum, kinetic, atomistic, etc. Each of them has its own field of applicability, its advantages, and disadvantages. Mathematical description of ns-laser ablation is usually carried out within the framework of continuum approach in the form of hydrodynamic models that take into account reaction of irradiated material to varying density, pressure, and energy both in the target and in the vapor-gas medium. Within the framework of continuum approach, a multiphase, multifront hydrodynamic model and computational algorithm were constructed that were designed for modeling ns-PLA of metal targets embedded in gaseous media. It is shown that proposed model and computational algorithm allow to carry out the simulation of interrelated mechanisms of heterogeneous and homogeneous evaporation of metals manifested as a series of explosive boiling. Modeling has shown that explosive boiling in metals occurs due to the presence of a near-surface temperature maximum. It has been established that in ns-PLA, exposure regimes can be realized in which a phase explosion is the main mechanism of material removal. The verification of reliability of obtained results was carried out by comparing experimental data and calculations with atomistic models

Synthesis of 2H-benzimidazole 1,3-dioxides, separase inhibitors, by reaction of o-benzoquinone dioximes with ketones

© 2017 Elsevier LtdThe synthesis of novel 2H-benzimidazole 1,3-dioxides on the basis of o-benzoquinone dioximes interaction with ketones in the presence of acids is described. Nitration of these compounds by nitric acid in acetic acid yields the 5-nitro derivatives of 2H-benzimidazole 1,3-dioxide

C-H/C-H COUPLING OF 4H-IMIDAZOLE-3 OXIDES WITH INDOLES IN THE SYNTHESIS OF BIFUNCTIONAL AZAHETEROCYCLIC DERIVATIVES

The study was carried out with the financial support of the Russian Science Foundation as a part of a research project 20-43-01004