Vol 64, No 3 (2019)

A new construction of a lowpass filter was developed based on a two-dimensional microstrip electromagnetic crystal, which had a steeper slope of the frequency response as compared to a filter consisting of a one-dimensional microstrip electromagnetic crystal. The investigated lowpass filter construction is characterized by a high workability and ease of manufacturing. Electrodynamic numerical simulation of the 3D model of the considered microstrip structure agrees well with the experiment, which allows conducting parametric synthesis of devices with the required properties using a personal computer.

A differential two-photon method of measuring the temperature of ⁴⁰Ca atoms in a continuously operating magneto-optical trap is demonstrated. Coherent two-photon resonances at the 4s²¹S₀–50¹S₀ Rydberg transition have been investigated experimentally using resonance laser beams propagating at different angles. The temperature of the cloud of ⁴⁰Ca atoms was measured depending on the frequency detuning of the cooling laser radiation.

A comparative analysis of experimental results obtained by various investigators using two different experimental approaches is presented: the phenomenological approach (the detection of conditions, characteristics, and modes of interaction between a projectile droplet and a target droplet) and the statistical approach (the analysis of collisions of tens and even hundreds of liquid droplets as a part of an aerosol). The ranges of values of the Weber criterion (the basic parameter used for analyzing the effects of collisions of droplets in a gaseous medium), which correspond to recoil, coagulation, expansion, and fragmentation are established according to the results of all experimental works considered.

The problems of modern robotics associated with the requirements for devices designed for various purposes are considered. The daVinci robotic surgical manipulation system is analyzed. The developed robotic system with a parallel structure designed for various kinds of surgical operations is proposed.

Guaranteed upper and lower estimates of the increment in the precession angle per nutation-angle period under nondegenerate motions of a Lagrange top have been obtained for arbitrary initial conditions and body parameters.

Certain results of the numerical investigation of the possibility of controlling the structure of flow near a V-shaped wing with an opening angle greater than π under an asymmetric flow around by a supersonic stream under the regimes with shock waves attached to the leading edges or with a centered rarefaction wave on the lee console are presented.

In this paper, we presented the results of experimental studies of the diffusion combustion of a plain hydrogen microjet flowing from a slit micronozzle at subsonic and supersonic speeds. For the first time, four scenarios of diffusion combustion of a plain hydrogen microjet including supersonic combustion in the presence of supersonic cells in both air and hydrogen are presented. The stabilization of the subsonic combustion of a hydrogen microjet was established to be due to the presence of a “flame constriction region,” while the stabilization of the supersonic combustion of a microjet was found to be associated with the presence of supersonic cells. The observed hysteresis of diffusion combustion of a plain hydrogen microjet depends on both the method of igniting the microjet (near or far from the nozzle exit) and the direction of change in the rate of its outflow (growth or reduction).

The results of multiyear investigations of cosmogenic radionuclide production rates along the orbits of 42 chondrites that fell to the Earth between 1959 and 2016 are presented. They constitute a long set of homogeneous data, statistical smoothing of which demonstrates some main regularities of the distribution and variation of the galactic cosmic rays (GCR) with energy >100 MeV in the internal (<5 AU) heliosphere. This set is exclusive, and it has timeless importance for all the future investigations of the magneto-hydrodynamic peculiarities of the GCR solar modulation mechanism. Analysis of the ²⁶Al contents in ten chondrites of known orbits allowed us to find the spatial profile of the GCR intensity (E > 100 MeV), averaged over a 1 My in the internal heliosphere, testifying to continual development and dissipation of a layer of the solar wind magnetic irregularities, which efficiently modulates cosmic radiation. It suggests constancy of the magneto-hydrodynamic environment in the Solar System for at least the last million years.