First-order Fermi acceleration processes at ultrarelativistic (γ ∼ 5-30) shocks are studied with the method of Monte Carlo simulations. The accelerated particle spectra are obtained by integrating the exact particle trajectories in a turbulent magnetic field near the shock. The magnetic field model assumes finite-amplitude perturbations within a wide wavevector range and with a predefined wave ...

When a plane shock hits a wedge head on, it experiences a reflectiondiffraction process and then a self-similar reflected shock moves outward as the original shock moves forward in time. Experimental, computational, and asymptotic analysis has shown that various patterns of shock reflection may occur, including regular and Mach reflection. However, most of the fundamental issues for shock refle...

There are various engineering systems which are subjected to shocks of random magnitudes at random times. The shock models can be classified in different ways. According to the cumulative shock model, the system breaks down because of a cumulative effect of shocks, while in an extreme shock model the system fails because of one single shock with large magnitude. See, for example, 1–9 for variou...

Abstract Collisionless shock heats ions very efficiently. Ion heating is a nonadiabatic process and the downstream temperature not proportional to upstream temperature. distributions just behind transition are gyrophase dependent gradually gyrotropize. With increase of Mach number contribution reflected into ion increases. Yet, directly transmitted may remain responsible for most Direct transmi...

In this paper, we consider a history-dependent mixed shock model which is combination of the extreme and $\delta$ -shock model. We assume that shocks occur according to generalized Pólya process contains homogeneous Poisson process, non-homogeneous as particular cases. For defined survival model, derive corresponding function, mean lifetime failure rate. Further, study asymptotic monotonicity p...

Introduction. The relevance of the study is determined both by importance problem digital transformation education in general, and specific conditions, which arose during crisis caused COVID-19. long-termconsequences emergency transition Russian to distance format, taking into account ongoing pandemic, have yet be assessed, but reaction ofthe participants educational process first period total ...

This article mainly studies the improvement of properties 1Cr18Ni9Ti material after laser shock peening. The is main used to make aviation ducts, and improving fatigue life ducts can significantly improve safety performance engines. combines simulation experiment study effect peening on material’s properties. results are as follows: test showed that, under same stress load, greatly extend speci...