Nonlinear Transformations of Pulsed Signals in Radar Tomography

Russian Physics Journal - This paper considers two methods for improving the visibility of hidden objects in radar tomography using nonlinear time transformations of short ultra-wideband (UWB)...     

Application of the High-Speed Photography Technique to Study Pulsed Vacuum Arc Plasma in a Short Gap

Physics of Atomic Nuclei - We studied the process of switching a short vacuum gap, initiated by an auxiliary discharge along the surface of the dielectric by registration images using an...     

Nonclassical behavior of solutions of linear second-order ordinary differential equations

We present a number of unstable second-order equations of the form

$$y'' + (1 + g(x))y = 0,$$

where the coefficient g(x) satisfies the conditions g(x) ∈ C(0, ∞) and lim_x→+∞ g(x)=0 but the maximum absolute values of solutions grow unboundedly (as power-law functions or even as exponentials).

     

Irregular Boundary Value Problems with Discontinuous Coefficients and the Eigenvalue Parameter

In this study, a Birkhoff-irregular boundary value problem for linear ordinary differential equations of the second order with discontinuous coefficients and the spectral parameter has been considered. Therefore, at the discontinuous point, two additional boundary conditions (called transmission conditions) have been added to the boundary conditions. The eigenvalue parameter is of the second degree in the differential equation and of the first degree in a boundary condition. The equation contains an abstract linear operator which is (usually) unbounded in the space Lq(−1, 1). Isomorphism and coerciveness with defects 1 and 2 are proved for this problem. The case of the biharmonic equation is also studied.     

On stabilization of implosion of condensed liners

This paper considers various experimental designs on the Atlas facility to study the physics of liners and determine the optimum conditions of their stable motion. In one of the versions, in comparison with the Liner Demonstration series of experiments, in which unstable liner motion was observed, it is proposed to reduce the initial liner radius without changing its mass, which, according to two-dimensional calculations, should to lead to more stable motion of the liner with unchanged velocity. It is also proposed to perform an experiment in which periodic perturbations at a certain wavelength are created on the outer surface of the liner with a simultaneous increase in its thickness. According to calculations, the growth of chaotic perturbations is stabilized in this case with the preservation of the liner velocity. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 3–14, May–June, 2009.