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Nanocluster structures can be easily modified in necessary direction and by controlled way in femtonanophotonics experiments. The variation of the key topology parameters can result in new type of the quantum correlation states/size effect for charged particles. In our earlier experiments we studied laser-induced topological nanoclusters structures of different types in thin films with unique phenomena in electrophysics and optics (see [1-3]). A simple 2-steps mechanism for enhancement of quantum behavior (e.g. in electroconductivity) exists for different conditions. First, when inelastic length linelastic > acluster we have no incoherent electron-phonon (e-ph) scattering, i.e. the coherent process takes place. Second, when de Broglie wave length λdB ≡ ℓcoh < Λ, (acluster – cluster size , Λ – spatial period of nanoparticle distribution) the coherent tunneling without loss occurs, and a long-range order with interference of the states takes place in the medium due to lattice structure.

Purpose: to conduct a hydrochemical analysis and give a comprehensive eco-toxicological assessment of the Kacha river water. Materials and methods. The content of chemical components in surface water was determined using titrimetric and photocolorimetric analyses. The degree of surface water pollution was calculated using a comprehensive assessment method on individual hydrochemical indicators, calculating the combinatorial water pollution index. Algotesting was carried out by measuring the optical density of the chlorella microalgae culture (Chlorella vulgaris Beijer). For phytotesting the seeds of dicotyledonous plants – cucumber (Cucumis sativus L.), soya bean (Glycine max (L.) Merr.) and monocotyledonous plants – common oats (Avena sativa L.) were used. Test parameters: seed germination and germination readiness, root and sprout length were analyzed. Results. According to the hydrochemical parameters of the Kacha river, the waters were classified as oligohaline, and according to the specific combinatorial index (S′ = 1.15) they were classified as slightly polluted ones of the second class. The values of the coefficient of complexity of water contamination rate during 2012–2018 were within 12 %. In 2023, the Kacha river water was defined as moderately hard water (7.4 mg-eq/cubic dm), while a decrease in the average water salinity (566.1 mg/cubic dm) and an improvement in its quality in terms of total iron (0.12 mg/cubic dm) were noted, which corresponded to the maximum permissible concentration for water bodies of municipal and amenity water use significance. The water algoeffect reached 57 %, and the phytoeffect – 87 %. Conclusions. The use of biological methods – algotesting and phytotesting – showed the presence of toxicants in the Kacha river water from the effluent to the mouth. The need for additional control of the river water quality during its use, including irrigation, was noted.

We studied in both theory and experiment the nanocluster structures of different types (due to topology and composition) taking into account the correlations in nanoparticle-ensemble by quantum states. The problem of high temperature superconductivity due to topological surface structures with localized states has been under our consideration. Dramatic enhancement of electroconductivity (in six orders!), observed in our experiments, may be discussed as a real tendency to high temperature superconductivity due to topological peculiarities of nanocluster system. Near-field photoluminescence spectra/optical response in hybrid nanosystems measured by us demonstrated a big efficiency in the nanoantenna respect.

The nanostructures with different morphology have been obtained by us by methods of both direct laser modification (from cw to fs laser radiation) of the target surface/thin films and laser evaporation of the target substance in liquid to produce the colloid systems, and then – to deposite substance on substrate from colloid, and also – by a single drop deposition technique. The analysis of induced nanostructures has been carried out by absorption spectroscopy, scanning electron microscopy and transmission electron microscopy. The island conductivity is dominant for the nanocluster semiconductor systems induced by laser ablation technique, and electroresistance can dramatically decrease due to spontaneous selected multichannel/parallel electron transportation trajectories. A tunneling quantum coherent effect takes place for electron conductivity for the case.

Arrays of memristive devices coupled with photosensors can be used for capturing and processing visual information, thereby realizing the concept of “in-sensor computing”. This is a promising concept associated with the development of compact and low-power machine vision devices, which is crucial important for bionic prostheses of eyes, on-board image recognition systems for unmanned vehicles, computer vision in robotics, etc. This concept can be applied for the creation of a memristor based neuromorphic analog machine vision systems, and here, we propose a new architecture for these systems in which captured visual data are fed to a spiking artificial neural network (SNN) based on memristive devices without analog-to-digital and digital-to-analog conversions. Such an approach opens up the opportunities of creating more compact, energy-efficient visual processing units for wearable, on-board, and embedded electronics for such areas as robotics, the Internet of Things, and neuroprosthetics, as well as other practical applications in the field of artificial intelligence.

We develop a method for the laser synthesis and deposition of carbon–gold films formed by a net of linear sp-carbon chains and stabilized by gold nanoparticles. The originality of the method is in the simultaneous production of carbon chains and gold nanoparticles due to the laser fragmentation of the amorphous carbon and hydrogen tetrachloroaurate (III) or chloroauric acid. We study how surface resistivity alters the effect of the obtained films via the illumination in the visible spectral range.

We predict an optical effect associated with systems, which exhibit topologically protected states separated by a finite distance. We develop a tight-binding model to calculate the optical selection rules in linear chains of atoms of different lengths, and show the crucial importance of edge states. For long enough molecules the interband transitions involving these edge states are in the highly sought-after THz frequency range. Although we have specifically considered finite carbon chains terminated by gold nanoparticles, the main results of our paper can be generalized to various systems, which exhibit topologically protected states separated by a finite distance.

We report on the fabrication of fractal dendrites using laser-induced melting of aluminum alloys. We target boron carbide (B4C), which is one of the most effective radiation-absorbing materials characterized by a low coefficient of thermal expansion. Due to the high fragility of B4C crystals, we were able to introduce its nanoparticles into a stabilization aluminum matrix of AA385.0. The high-intensity laser field action led to the formation of composite dendrite structures under the effect of local surface melting. Modelling the dendrite cluster growth confirms its fractal nature and sheds light on the pattern behavior of the resulting quasicrystal structure.

The formation of macroscale carbon structures characterised by an sp-sp2-hybridization is realised by self-assembly in colloidal solutions under an effect of laser irradiation and electromagnetic fields. The sponge-like morphology, sculptured with gold nanoparticles (NPs) was revealed by Scanning Electron Microscopy (SEM) imaging. Full structural and defect characterization of the self-assembled sponges was provided using the micro-Raman spectroscopic technique. The synthesized clusters manifest themselves in the presence of a strong spectral band in the visible range of the photoluminescence spectra that is quite unusual for ordered sp2-carbon systems.

Arrays of memristive devices coupled with photosensors can be used for capturing and processing visual information, thereby realizing the concept of "in-sensor computing". This is a promising concept associated with the development of compact and low-power machine vision devices, which is crucial important for bionic prostheses of eyes, on-board image recognition systems for unmanned vehicles, computer vision in robotics, etc. This concept can be applied for the creation of a memristor based neuromorphic analog machine vision systems, and here, we propose a new architecture for these systems in which captured visual data are fed to a spiking artificial neural network (SNN) based on memristive devices without analog-to-digital and digital-to-analog conversions. Such an approach opens up the opportunities of creating more compact, energy-efficient visual processing units for wearable, on-board, and embedded electronics for such areas as robotics, the Internet of Things, and neuroprosthetics, as well as other practical applications in the field of artificial intelligence. [ABSTRACT FROM AUTHOR]

Shungite carbon (ShC) nanoparticles in the form of stable aqueous dispersions represent a promising solution for optical and biomedical applications. The dispersion is an interesting phenomenon from the point of view of stabilization of ShC nanoparticles and their structural constituents up to the basic structural unit, namely a graphene fragment. Herein, we used these aqueous dispersions with easily released structural components to study laser irradiation with various durations and obtain hybrids of ShC with Ag and Au nanoparticles. The main role in the stabilization of ShC nanoparticles belongs to the graphene fragments and their stacks, which display a considerable dipole moment. Newly prepared aqueous dispersions of ShC–metal hybrid nanoparticles retained the stability inherent in the original nanoparticles both of ShC and metals. Changes in the size distribution pattern of nanoparticles in dispersions upon ablation were studied by dynamic light scattering (DLS). Raman with UV-Vis spectroscopy methods were applied to trace structural changes in ShC upon the formation of hybrid nanoparticles. Films obtained by condensation of the dispersions on glass substrates display periodic structures, as was revealed by SEM microscopy. There, the conditions under which nanoparticles lose their ability to disperse in water and retain a graphene-like structure in a film were revealed. [ABSTRACT FROM AUTHOR]

We stabilize monoatomic carbon chains in water by attaching them to gold nanoparticles (NPs) by means of the laser ablation process. Resulting nanoobjects represent pairs of NPs connected by multiple straight carbon chains of several nanometer lengths. If NPs at the opposite ends of a chain differ in size, the structure acquires a dipole moment due to the difference in work functions of the two NPs. We take advantage of the dipole polarisation of carbon chains for ordering them by the external electric field. We deposit them on a glass substrate by the sputtering method in the presence of static electric fields of magnitudes up to 105 V/m. The formation of one-dimensional carbyne quasi-crystals deposited on a substrate is evidenced by high-resolution TEM and X-ray diffraction measurements. The original kinetic model describing the dynamics of ballistically flowing nano-dipoles reproduces the experimental diagram of orientation of the deposited chains. [ABSTRACT FROM AUTHOR]

Moving nanosecond laser system is used for laser-assisted thermodiffusion deposition of metallic nanoparticles from water-based colloidal solutions. The results obtained for both gold and silver nanoparticles show that film morphology strongly depends on laser scanning speed and the number of passages. We show, furthermore, the possibility of producing bimetallic Au:Ag thin films by laser irradiation of the mixed solutions. As a result of several laser scans, granular nanometric films are found to grow with a well-controlled composition, thickness, and morphology. By changing laser scanning parameters, film morphology can be varied from island structures to quasi-periodic arrays. The optical properties of the deposited structures are found to depend on the film composition, thickness, and mean separation between the particles. The transparency spectra of the deposited films are shown to be defined by their morphology. [ABSTRACT FROM AUTHOR]