Diffuse X-ray scattering from crystalline structures with quantum dots of pyramidal shape

Diffuse scattering from crystalline structures with quantum dots (QDs) in the shape of a regular truncated pyramid with a square base is investigated. The elastic strains around QDs are calculated using the Green function method. The fields of the QD atomic displacements and the angular distribution of scattering intensity in the reciprocal space as functions of the QD concentration are simulated numerically. The influence of a pyramidal QD cross section by the diffraction plane on the diffuse X-ray scattering is demonstrated.     

Hybrid Electromagnetic System for Acceleration of Solids

The electroexplosive and electrothermal mechanisms and the principles of conduction and induction electrodynamics are used simultaneously to convert electromagnetic energy to the kinetic energy of projectiles. This approach is implemented on the basis of the well–known configuration of a coaxial pinch accelerator. It is established that there is an active lengths of the barrel on which the system ensures launching with nearly constant acceleration. For a barrel length of 340 mm and a barrel diameter of 17 mm, bodies with a mass of 1—12 g are accelerated to velocities of 3.4—1.45 km/sec with an energy conversion efficiency of 25—29% at a capacitive storage voltage of 1.75 kV and a discharge current of up to 150 kA. Bodies with a mass of 40—80 g (barrel diameter 25 mm are accelerated to velocities of 1.3—1.0 km/sec with an efficiency of 28—20% at a voltage of 3.5 kV and a current of up to 220 kA.     

The oscillator strength of the πg shape resonance in the absorption K-spectrum of a nitrogen molecule

Magnitudes of the absorption cross sections of a nitrogen molecule are measured by the transmission method near the ionization K-threshold. Based on these data, the partial absorption NK cross sections are obtained and the oscillator strength of the π_g shape resonance is determined. It is found that the oscillator strength of the π_g-resonance increases as the optical density of nitrogen decreases. This phenomenon is interpreted as a result of the instrumental distortion effect (the thickness effect). By extrapolating to zero pressure, the oscillator strength of the π_g shape resonance is determined to be 0.29.     

Influence of temperature effects on the domain structure of iron-nickel films

The change in the macroscopic domain structure and magnetization ripples of iron-nickel films is investigated in the UÉMV-100 electron microscope during heating from room temperature to 550°C.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 97–100, June, 1972.In conclusion, the authors are grateful to I. S. Edel'man for useful comments and assistance in the research.     

Increase in the Acceleration Efficiency of Solids in a Hybrid Coaxial Magnetoplasma Accelerator

It is shown that in a hybrid coaxial magnetoplasma accelerator with a channel length of 350 mm and a diameter of 23 mm, the acceleration velocity and the energy conversion efficiency increase as the length of the plasma structure formation channel filled with a gas-generating material decreases from 17 to 9 mm. It is found that it is reasonable to use paraffin as the gas-generating material as it has a less significant deionizing effect on the high-current arc discharge and hence causes a less significant decrease in the discharge current intensity and an increase in conductive and inductive electrodynamic forces.     

Analysis of the dynamic synthesis superdispersed product in a C-N system by high resolution electron microscopy

We report on the results of analysis of the superdispersed product synthesized in a superfast jet of electric-discharge carbon plasma flowing to the nitrogen atmosphere. The data obtained by high resolution transmission electron microscopy indicate the presence of the α phase of hypothetic carbon nitride C₃N₄ in the form of unique quasi-two-dimensional multilayer particles.