卷 9, 编号 1 (2024)

The paper presents brief biographical information for the 100th anniversary of Roger Guillemin, a distinguished American scientist who won the 1977 Nobel Prize in Physiology or Medicine. He shared half of the prize with Andrew W. Schally “for their discoveries concerning the peptide hormone production of the brain”; the other half went to Rosalyn S. Yalow “for the development of radioimmunoassays of peptide hormones”. The paper briefly describes the main scientific achievements of R. Guillemin in the development of neuroendocrinology. He isolated somatotropin (growth hormone), identified molecules of thyrotropin-releasing hormone thyreoliberin, which controls all thyroid functions, as well as dozens of other molecules from the hypothalamus. His research has led to the development of treatments for diseases ranging from infertility to pituitary tumors. With his discoveries of certain information flows in the human brain, he contributed to deciphering the code of human life. Guillemin's early training in the construction of radio receivers and transmitters was of great importance, and his serious experience with computers has led him to become one of the pioneers in digital painting. R. Guillemin retired from active scientific life only three years ago.

Using the method of polymerized complex precursors (PCP) and a wide range of chelating agents, we synthesized metal oxide catalysts (MOCs) with a general composition of Me₂Co / CaCO₃ (CaO, MgO, NaCl, Me – Fe, Ni) and a molar ratio of Me₂Co / carrier from 0.06 : 1 to 0.55 : 1; the effectiveness of such MOCs in the synthesis of carbon nanotubes by catalytic chemical vapor deposition was determined from the gas phase (CCVD synthesis). The dependence of the specific yield and morphology of the carbon product on the MOСs composition and the nature of the chelating agent, being a decisive factor in the process of preorganization of the catalyst structure, has been established. The use of catalysts for the growth of CNTs with the composition of Ni₂Co / CaCO₃ (CaO) allows the СCVD process to be carried out at low temperatures (450–500 °C) in contrast to 800 °C for MOСs with the composition of Fe₂Co / CaCO₃ (CaO) and leads to the formation of structurally homogeneous arrays of multi-walled carbon nanotubes. At the same time, the specific yield of CNTs decreases with an increase in the temperature of the process, but an increase in the mole fraction of active metals in the catalyst leads to an increase in the specific yield of CNTs. Yet, the dependence has the form of a curve with a tendency to reach a plateau, which indicates an increase in the processes of agglomeration of metal nanoparticles, increasing their size and, due to this, reducing the possibility of nucleation of carbon nanotubes. It has been suggested that low-temperature CCVD synthesis using MOC composition Ni₂Co / CaCO₃ (CaO, MgO, NaCl) is realized due to the unique magnetic and electronic properties of the Ni – NiO system, which makes it possible to initiate the process of nucleation and then growth of nuclei of catalytic nickel particles at temperatures exceeding the Curie point Ni (> 360 °С).

A study was carried out to examine the effects of interaction and efficiency of the particle separation process by size and density in fast gravity flows activated by longitudinal momentum by acting the particles of the open surface of the flow with a rough conveyor belt. It has been established that the momentum effect leads to a zone formation in the central part of the flow. The zone has extremely high values of the shear rate and the gradient of the voids fraction, ensuring an intensive occurrence of the quasi-diffusion separation effect. In the region adjacent to the base of the flow, momentum action leads to a decrease in the proportion of voids and an increase in the shear rate, which contributes to the intensification of particle size segregation. In the flow region adjacent to the surface of the momentum action, high values of the voids fraction and the temperature of the granular medium provide favorable conditions for the occurrence of quasi-diffusion effects of mixing and separation. As a result of momentum action, the separation efficiency increases if the direction of the quasi-diffusion separation and segregation flows coincides (separation by density), and the efficiency decreases when the directions of these flows are different (separation by size). With increasing intensity of the momentum action, the zone of intense shear deepens, and the efficiency of density separation increases, reaching its maximum value when the zone deepens by 0.5–0.55 of the layer thickness. With a further increase in the intensity of the momentum action, the separation efficiency decreases due to the expansion of the flow region in which the effect of quasi-diffusion mixing dominates. The conclusions based on the experimental results are confirmed by the method of mathematical modeling of the dynamics of particle separation by density in an activated gravity flow.

The paper presents the results obtained from the studies of the processes of controlled laser synthesis of nanocluster / island nanofilms of different topological configurations of tens and hundreds of nanometers. The findings on structures with lead telluride (PbTe) and quantum bistability in a polariton-exciton system are considered separately. The analysis of the algorithms and computational models used to solve these problems are carried out, and a number of obtained and observed images for different surface nanostructures are presented. These issues are also considered in terms of the topological configuration influence, e.g. on the surface electrical conductivity of the samples under study, as well on other functional characteristics. The phenomenon of quantum bistability in the model of excitonic polaritons and the corresponding modes of its manifestation in 1D-columnar-type semiconductor microcavities, which can be considered as analogues of systems with carbon nanotubes, are also briefly discussed. It is modern advances in the technology of their production on an industrial scale, including bundles and threads of nanotubes, that allow talking about the possibility of their widespread usein micro-nanoelectronics, in particular, as elements of logic devices of various types, as well as sensitive universal sensors for various applications.