Table of contents

Processes with K-mesons that are due to weak flavor changing neutral currents (FCNC) are considered, primarily, the theoretically clean `golden decays' and . Experimental data for these and other processes violating CP invariance are discussed, and the prospects of future studies are examined. The results of experiments with kaons are compared with those obtained for B-mesons (CP-odd asymmetry in the decays , mixing). A possible interpretation of the data on the decays , , and is discussed within the framework of the Standard Model and of New Physics models.

After a brief review of the main areas of research in X-ray optics and an analysis of the development of capillary optics, a general theory of radiation propagation through capillary structures is described in both geometrical optics and wave optics approximations. Analysis of the radiation field structure inside a capillary waveguide shows that wave propagation in channels can be of a purely modal nature, with the transmitted energy mostly concentrated in the immediate neighborhood of the capillary inner walls. A qualitative change in radiation scattering with decreasing channel diameter — namely, the transition from surface channeling in microcapillaries to bulk channeling in nanocapillaries — is discussed.

The state of the art of research into the diffusion of hydrogen in metallic systems with chemical and crystalline disorder is reviewed. The physical principles and capabilities of existing experimental methods for studying hydrogen diffusion in equilibrium and nonequilibrium conditions are discussed. The current theoretical understanding of and approaches to the problem are critically analyzed. Based on the authors' original research, a quite general formalism is proposed for describing hydrogen diffusion on disordered media, which allows the analytical solution of the problem and — very importantly — enables diffusion and structural data to be used to identify the structure of amorphous and nanocrystalline alloys.

We consider a few thought experiments of radial motion of massive particles in the gravitational fields outside and inside various celestial bodies: Earth, Sun, black hole. All other interactions except gravity are disregarded. For the outside motion there exists a critical value of coordinate velocity : particles with v < v_c are accelerated by the field like Newtonian apples, and particles with v > v_c are decelerated like photons. Particles moving inside a body with constant density have no critical velocity; they are always accelerated. We consider also the motion of a ball inside a tower, when it is thrown from the top (bottom) of the tower and after elastically bouncing at the bottom (top) comes back to the original point. The total time of flight is the same in these two cases if the initial proper velocity v₀ is equal to .

The history of the discovery of combination (Raman) scattering of light in Moscow and Calcutta is briefly described. Moscow physicists observed the lines due to the new effect on February 21, 1928 and published their results on July 13, 1928, whereas for Indian physicists the respective dates are February 28, 1928 and April 21, 1928. Raman alone was to be awarded the Nobel Prize for the discovery. Research conditions in Russia and India are discussed in brief.