Co-fibered products of algebraic curves

We give examples of failure of the existence of co-fibered products in the category of algebraic curves.      

Influence of the substrate on negative index fishnet metamaterials

We analyze numerically the influence of the dielectric substrate on the optical response and effective macroscopic parameters of fishnet metamaterials. We show that the substrate can suppress the region of the negative refractive index due to the weakening of the gap plasmon associated with the magnetic resonance of the structure. We also demonstrate that the effect of substrate vanishes when the number of the functional layers increases.     

Resonance method of electric-dipole-moment measurements in storage rings

A "resonance method" of measuring the electric dipole moment (EDM) of nuclei in storage rings is described, based on two new ideas: (1) Oscillating particles' velocities in resonance with spin precession, and (2) alternately producing two sub-beams with different betatron tunes--one sub-beam to amplify and thus make it easier to correct ring imperfections that produce false signals imitating EDM signals, and the other to make the EDM measurement.     

Electromagnetically induced coherent backscattering

We demonstrate a strong coherent backward wave oscillation using forward propagating fields only. This is achieved by applying laser fields to an ultradispersive medium with proper chosen detunings to excite a molecular vibrational coherence that corresponds to a backward propagating wave. The physics then has much in common with the propagation of ultraslow light. Applications to coherent scattering and remote sensing are discussed.     

Dirac and Majorana neutrinos in matter

We consider the matter effects on neutrinos moving in background on the basis of the corresponding quantum wave equations. Both Dirac and Majorana neutrino cases are discussed. The effects for Dirac neutrino reflection and trapping as well as neutrino—antineutrino annihilation and ν pair creation in matter at the interface between two media with different densities are considered. The spin light of neutrinos in matter is also discussed. The text was submitted by the authors in English.     

A multichannel adaptive interferometry system

A multichannel adaptive interferometer based on dynamic reflecting holograms multiplexing in a photorefractive crystal of cubic symmetry is proposed. The efficiency of hologram multiplexing is studied theoretically and experimentally. For the recording geometry used, a crosstalk between channels is shown to be less than the single-channel inherent noise for a wide angular range of beams entering the crystal, and the sensitivity depletion in one channel is insignificant for a large number of channels.     

Nonlinear surface waves in arrays of curved waveguides

We study both theoretically and experimentally the nonlinear surface waves at the edge of curved waveguide arrays with a surface defect. We show that the nonlinear coupling between different linear modes supported by the array can lead to beam switching to different output waveguides with increasing of the nonlinearity strength. Our experimental observations are in good agreement with the numerical modelling.     

Novel structural type of bridged urea derivatives bearing azatricyclo[4.3.1.03,8]decane moiety

Structural Chemistry - In an attempt to synthesize 4-thia-6-azatricyclo[5.3.1.13,9]dodecan-5-imine as putative antihypotensive agent with prolonged effect, a reaction of...     

Organic crystallography: three decades after Kitaigorodskii

Structural Chemistry - Main postulates of Aleksandr Kitaigorodskii’s theory of organic crystal structures are revisited. The additive model of van der Waals atom-atom potentials giving rise...