Academy of Sciences of Uzbekistan

Single crystals of the organic–inorganic hybrid bis((pyridin-1-ium-3-yl)methanaminium) hexachlorostannate(IV) dichloride, ([3-PyCH2NH3]2[SnCl6]Cl2), were grown and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes as a centrosymmetric structure comprising discrete octahedral [SnCl6]2– anions linked to protonated organic cations through charge-assisted N–H···Cl hydrogen bonds, forming a stable supramolecular framework. Bond valence sum calculations confirm the + 4 oxidation state of tin, supporting the structural model. Diffuse reflectance spectroscopy reveals a wide optical bandgap of 4.28 eV, indicating insulating behavior typical of chloride-based hybrids. Photoluminescence measurements show near-ultraviolet emission at room temperature, attributed to ligand-centered electronic transitions within the organic component. Third-order non-linear optical measurements demonstrate a measurable χ(3) value on the order of 10–11 esu, suggesting significant electronic polarization despite the centrosymmetric lattice. Dielectric analysis indicates strong frequency and temperature-dependent behavior, with higher dielectric constants at low frequencies due to interfacial and space-charge polarization, followed by stabilization at higher frequencies. AC conductivity studies suggest a transition from polarization-dominated transport to thermally activated hopping conduction. Hirshfeld surface analysis confirms that N–H···Cl hydrogen bonding dominates crystal packing. These results demonstrate the key role of hydrogen-bond-driven organization in determining the optical and dielectric properties of this hybrid material.

Zinc oxide nanoparticles (ZnO NPs) have already shown potential applications as antimicrobial agents. However, the large band gap and charge carrier recombination of ZnO NPs reduce the production of reactive oxygen species, which limits their antibacterial activity; therefore, further modifications of their structural and electronic properties are required. Herein, Cu doping of ZnO NPs has been carried out by a microwave-assisted method to modify their structural, electronic, and biological properties. The structural and morphological analysis of the prepared Cu-doped ZnO NPs confirmed that Cu is well incorporated into the ZnO NPs lattice, and the morphology is quasi-spherical with a diameter range of 20–25 nm. The changes in the band gap and defect states in ZnO NPs, formed upon Cu doping, were confirmed by UV-visible and theoretical analysis. The antimicrobial potential of ZnO and Cu-doped ZnO NPs against S. aureus, E. coli, P. aeruginosa, and C. albicans has been evaluated by measuring the zone of inhibition, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The results showed an enhancement of the antimicrobial potential of ZnO NPs upon Cu doping, which could be related to modifications of the electronic structure that could potentially affect redox properties.

This study investigates the influence of boron (B) doping on the electrical and thermal transport properties of double-walled carbon nanotubes (DWCNT) with chiral indices (8,0) @ (17,0) over a wide temperature range. Boron incorporation modulates the partial charge distribution, enhancing p-type semiconducting behavior at low doping concentrations, while higher doping levels induce substitutional disorder and defect formation, leading to reduced electrical conductivity. Thermal transport is also affected, as defect-induced phonon scattering and mass-difference effects suppress phonon propagation at elevated doping levels. The results highlight the critical role of both dopant concentration and temperature in controlling charge redistribution, phonon scattering, and overall transport efficiency in DWCNT. All simulations were performed using classical molecular dynamics (MD) techniques. Double-walled carbon nanotube structures with chiral indices (8,0)@(17,0) were constructed and doped with boron at concentrations ranging from 0 to 9.65%. Partial atomic charges were analyzed to study charge redistribution, and non-equilibrium MD simulations were employed to compute thermal conductivity. Temperature-dependent behavior was evaluated by performing simulations across a broad temperature range. The interactions between carbon and boron atoms were modeled using validated force fields suitable for covalent systems, and phonon scattering effects were analyzed to quantify the impact of doping on thermal transport.

We assess whether Calligonum zakirovii and C. junceum—two representative taxa of Central Asian Calligonum—constitute separate species or a single polymorphic lineage. To do so, we integrated fruit morphometrics, nuclear ITS and six plastid loci (psbA-trnH, psbM-ycf6, rpl32-trnL, trnL-F, rbcL, and matK), 17 SSR markers, and genome-wide SNPs. SSR markers partitioned most variation within populations, whereas Sanger-sequenced loci and whole-genome SNP data recovered all samples as a single lineage. Molecular clock dating of the ITS dataset estimates the most recent common ancestor of the two taxa at 2.96 Ma (95

We consider a three-state solid-on-solid (SOS) model in the presence of a nonzero external field on a Cayley tree. A system of functional equations corresponding to this model is derived, where each solution defines a quasi Gibbs measure. Based on this system, we investigate the translation-invariant p -adic quasi Gibbs measures (TIpQGMs) of the model. In the case of a binary Cayley tree, we explicitly determine the TIpQGMs under the same conditions. Furthermore, by analyzing the boundedness of these measures, we establish the existence of a phase transition.