The materials of The International Scientific – Practical Conference is presented below.
The Conference reflects the modern state of innovation in education, science, industry and social-economic sphere, from the standpoint of introducing new information technologies.
It is interesting for a wide range of researchers, teachers, graduate students and professionals in the field of innovation and information technologies.
How is a water-soluble globular protein able to spontaneously cross a cellular membrane? It is commonly accepted that it undergoes significant structural rearrangements on the lipid-water interface, thus acquiring membrane binding and penetration ability. In this study molecular dynamics (MD) simulations have been used to explore large-scale conformational changes of the globular viscumin A chain in a complex environment – comprising urea and chloroform/methanol (CHCl3/MeOH) mixture. Being well-packed in aqueous solution, viscumin A undergoes global structural rearrangements in both organic media. In urea, the protein is “swelling” and gradually loses its long-distance contacts, thus resembling the “molten globule” state. In CHCl3/MeOH, viscumin A is in effect turned “inside out”. This is accompanied with strengthening of the secondary structure and surface exposure of hydrophobic epitopes originally buried inside the globule. Resulting solvent-adapted models were further subjected to Monte Carlo simulations with an implicit hydrophobic slab membrane. In contrast to only a few point surface contacts in water and two short regions with weak protein-lipid interactions in urea, MD-derived structures in CHCl3/MeOH reveal multiple determinants of membrane interaction. Consequently it is now possible to propose a specific pathway for the structural adaptation of viscumin A with respect to the cell membrane – a probable first step of its translocation into cytoplasmic targets.
The use of improved fabrication technology, highly disordered NbN thin films, and intertwined section topology makes it possible to create high-performance photon-number-resolving superconducting single-photon detectors (PNR SSPDs) that are comparable to conventional single-element SSPDs at the telecom range. The developed four-section PNR SSPD has simultaneously an 86±3%86±3% system detection efficiency, 35 cps dark count rate, ∼2 ns∼2 ns dead time, and maximum 90 ps jitter. An investigation of the PNR SSPD’s detection efficiency for multiphoton events shows good uniformity across sections. As a result, such a PNR SSPD is a good candidate for retrieving the photon statistics for light sources and quantum key distribution systems.
Single crystal of TlCl was doped with NIR photoluminescent univalent bismuth cations by prolonged immersion in liquid bismuth metal. The ion exchange Tl+ + Bi0 ↔ Tl0 + Bi+ at the crystal surface with subsequent Bi+ migration to the bulk are expected to drive the doping process. Contrary with Bi‐doped TlCl crystals, grown by Bridgman method, the ion exchange does not produce the additional nonluminescent bismuth‐containing centers. The investigation of photoluminescence emission and excitation spectra lead to the conclusion, that Bi+ is the main NIR emissive center in Bi‐doped TlCl.
We report on the quantum yield (eta) and decay time (tau) measurements at room temperature for the bright red-orange (602 nm) luminescence from new germanium-vacancy (Ge-V) centers in nano- and microcrystalline diamonds synthesized at high pressure and high temperature. The values eta = 3 +/- 1% and tau = 6.2 +/- 0.2 ns were found. The Stokes shift measured as the energy difference between the maxima of the luminescence and luminescence excitation spectra is negligible. The relative intensity of the zero-phonon line constitutes up to 70% from the total intensity of the luminescence. Results of our ab initio DFT calculations for the ground-state electronic and vibrational structure of (Ge-V)(-) in diamond are presented and discussed.
The effect of spherical SiO2 nanoparticles of 20 to 80 nm in diameter embedded into the PEDOT: PSS buffer layer of organic solar cells (OSC) based on star-shaped oligomers on their efficiency was studied experimentally in detail. Measurements and analysis of the current-voltage characteristics of the samples, their absorption spectra and study of the morphology of the surface of the buffer layer with embedded nanoparticles were carried out. It is shown an increase in the OSE efficiency for the case of embedded into the PEDOT:PSS layer SiO2 nanoparticles with a diameter of 20 and 50 nm, which slightly depends on the concentration of the nanoparticles in the buffer layer.
We will present the novel experimental far-field optical microscopy technique for detection of single nanoparticles, which weakly absorb a visible light and are characterized by refractive index close to its value in nearby environment (including particles of organic and biological origin: polymer nanoparticles, microand extracellular vesicles, liposomes, viruses etc)
We investigate thermal properties of a NbN single-photon detector capable of unit internal detec- tion efficiency. Using an independent calibration of the coupling losses we determine the absolute optical power absorbed by the NbN film and, via a resistive superconductor thermometry, the ther- mal resistance Z(T) of the NbN film in dependence of temperature. In principle, this approach permits a simultaneous measurement of the electron-phonon and phonon-escape contributions to the energy relaxation, which in our case is ambiguous for their similar temperature dependencies. We analyze the Z(T) within the two-temperature model and impose an upper bound on the ratio of electron and phonon heat capacities in NbN, which is surprisingly close to a recent theoretical lower bound for the same quantity in similar devices.
The formation and properties of locally tensile strained Ge microstructures (“microbridges”) based on Ge layers grown on silicon substrates are investigated. The elastic-strain distribution in suspended Ge microbridges is analyzed theoretically. This analysis indicates that, in order to attain the maximum tensile strain within a microbridge, the accumulation of strain in all corners of the fabricated microstructure has to be minimized. Measurements of the local strain using Raman scattering show significant enhancement of the tensile strain from 0.2–0.25% in the initial Ge film to ~2.4% in the Ge microbridges. A considerable increase in the luminescence intensity and significant modification of its spectrum in the regions of maximum tensile strain in Ge microbridges and in their vicinity as compared to weakly strained regions of the initial Ge film is demonstrated by microphotoluminescence spectroscopy.
It is well known that superconducting films made of a type-I material can demonstrate a type-II magnetic response, developing stable vortex configurations in a perpendicular magnetic field. Here we show that the superconducting state of a type-I nanowire undergoes more complex transformations, depending on the nanowire thickness. Sufficiently thin nanowires deviate from type I and develop multiquantum vortices and vortex clusters similar to intertype (IT) vortex states in bulk superconductors between conventional superconductivity types I and II. When the nanowire thickness decreases further, the quasi-one-dimensional vortex matter evolves towards type II so that the IT vortex configurations gradually disappear in favor of the standard Abrikosov lattice (chain) of single-quantum vortices. However, type II is not reached. Instead, an ultrathin nanowire re-enters abruptly the type-I regime while vortices tend to be suppressed by the boundaries, eventually becoming one-dimensional phase-slip centers. Our results demonstrate that arrays of nanowires can be used to construct composite superconducting materials with a widely tunable magnetic response.