Cosmic rays as a new instrument of seismological studies

The state of the art of the short-termearthquake prediction problemis considered. A new method for monitoring the 3D stress state in the earthquake-prone zone using high-energy muons in cosmic rays and simultaneous measurements of acoustic and seismic signals in the frequency range from 1 Hz to 1–2 kHz is proposed. To implement this method, muons should be detected simultaneously with extensive air showers in an area of several square kilometers.     

Formation of nitrogen oxides in detonation waves

Based on detailed kinetic calculations and experimental data, it is demonstrated that the emission of nitrogen oxides from detonation burner units (DBUs) is significantly lower than that from powerful conventional burners with similar characteristics. Under certain conditions, realized largely in DBUs with rotating detonation, the main component of the nitrogen oxides may turn out to be N₂O.     

Negative Differential Resistance and Shapiro Steps in a Superconducting MoN Strip with a Cut

JETP Letters - Regions with a negative differential resistance have been revealed in the voltage–current characteristics of superconducting MoN strips with a side cut under high-power...     

Ordering of MX y nonstoichiometric compounds with the formation of M 2 X superstructures

A symmetry analysis of trigonal, cubic, and tetragonal superstructures of the M ₂ X type that are formed in strongly nonstoichiometric compounds MX _y with the B1 structure has been performed. The channels of disorder-order transitions MX _y → M ₂ X have been determined. It has been demonstrated that, in nonstoichiometric carbides and nitrides MX _y of Group IV transition metals, a decrease in the temperature can lead to three physically allowable sequences of transformations associated with the formation of M ₂ X ordered phases.     

Iron Nanoparticles in Severe-plastic-deformed Copper

Superparamagnetic iron nanoparticles with a size of a few nanometers were produced in copper by severe plastic deformation. In a isochronal annealing experiment near a temperature of 450K, which corresponds to the temperature of structural relaxation and the first step of grain growth (from 128 to 150nm) of submicrocrystalline copper, an abrupt increase in the magnetic susceptibility is detected. This increase is shown to be due to iron nanoparticles increasing in size from 2.8 to 3.3nm. The vanishing of the ferromagnetic contribution by iron nanoparticles observed at 850K, well below the Curie temperature of iron, is due to the dissolution of nanoparticles in plastically deformed copper.     

Chemistry of polyenic and polyacetylenic compounds Communication 12. Hydration of tertiary diacetylenic alcohols and glycols

Summary A study was made of the hydration of tertiary diacetylenic glycols under the action of aqueous dimethylamine solution, which leads to substituted 3(2H)-furanones. Under the conditions of acid hydration, 2-methyl-3,5-hexadiyn2-ol also gives the corresponding furanone.