Symmetrization of the nonlinear system of gas dynamics equations

We describe a method for representing the nonlinear system of gas dynamics equations in quasilinear form with symmetric coefficient matrices and, moreover, with a positive definite matrix at the time derivative.     

New physics at 1 TeV?

If decays of a heavy particle S are responsible for the diphoton excess with invariant mass 750 GeV observed at the 13 TeV LHC run, it can be easily accommodated in the Standard Model. Two scenarios are considered: production in gluon fusion through a loop of heavy isosinglet quark(s) and production in photon fusion through a loop of heavy isosinglet leptons. In the second case, many heavy leptons are needed or/and they should have large electric charges in order to reproduce experimental data on σ_{pp → SX} · Br(S → γγ).     

Shock structure in a viscoelastic medium with a nonlinear dependence of the Maxwellian viscosity on the parameters of the material

The shock-profile structure in a viscoelastic medium with a nonlinear dependence of the Maxwellian viscosity (a quantity inverse to the tangential stress-relaxation time ) on the substance parameters is investigated in this paper on the basis of a model proposed in [1]. The presence of such a dependence of the relaxation time permitted the extraction of sections with an abrupt change in the quantities on the profile, called plastic waves, by using additional relationships. The model of the isotropic medium used is characterized by an equation of state in the form of a dependence of the density of the internal energy E per unit mass on the strain-tensor invariants and the entropy S.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 5, pp. 101–108, September–October, 1974.     

Determination of the potential functions of molecular inversion from experimental data: Current state and problems

Various approximations of the method of determining two-well potential functions of molecular inversion from experimental data (geometrical parameters and inversion level energies) are considered. The potential of the method is illustrated by reference to carbonyl molecules in the lowest excited states. Some of the current problems are discussed. Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 5, pp. 947–961, September–October, 1998     

Study of Entropy Properties of a Linearized Version of Godunov’s Method

Computational Mathematics and Mathematical Physics - The ideas of formulating a weak solution for a hyperbolic system of one-dimensional gas dynamics equations are presented. An important aspect is...     

Thermodynamically consistent nonlinear model of elastoplastic Maxwell medium

The paper is devoted to new applications of the ideas underlying Godunov’s method that was developed as early as in the 1950s for solving fluid dynamics problems. This paper deals with elastoplastic problems. Based on an elastic model and its modification obtained by introducing the Maxwell viscosity, a method for modeling plastic deformations is proposed.