The Stability of Hybrid Perovskites with UiO-66 Metal-Organic Framework Additives with Heat, Light, and Humidity.

This study is devoted to investigating the stability of metal-organic framework (MOF)-hybrid perovskites consisting of CHNHPbI (MAPbI) and UiO-66 without a functional group and UiO-66 with different COOH, NH,and F functional groups under external influences including heat, light, and humidity. By conducting crystallinity, optical, and X-ray photoelectron spectra (XPS) measurements after long-term aging, all of the prepared MAPbI3@UiO-66 nanocomposites (with pristine UiO-66 or UiO-66 with additional functional groups) were stable to light soaking and a relative humidity (RH) of 50%. Moreover, the UiO-66 and UiO-66-(F) hybrid perovskite films possessed a higher heat tolerance than the other two UiO-66 with the additional functional groups of NH and COOH.

Regulation of the Concentration Heterogeneity and Thermal Expansion Coefficient in the Metastable Invar FeNi Alloy.

Mössbauer spectroscopy and electron microscopy study of the active redistribution of Ni atoms during the process of polymorphous transformation α→γ in the metastable FeNi alloy revealed that slow heating (at the rate of 0.2 K/min) results in the depletion of the initial α-phase with a beneficiation of developing disperse γ-phase plates according to the equilibrium diagram. A regulation possibility of the concentration heterogeneity and austenite thermal expansion coefficient resulted from the polymorphous transformation α→γ was shown.

Nearly compensated ferrimagnetic behaviour and giant exchange bias of hexagonal MnPtAl: experimental and theoretical studies.

We have investigated the MnPtAl Heulser alloy to unravel its structural, magnetic, calorimetric and electronic structure properties. At room temperature, the alloy crystallizes in a hexagonal structure. Magnetization reveals a weak martensitic transition at 307 K, followed by a long range ferrimagnetic transition at 90 K.

Fish otoliths as biological dosimeter: internal dose calculation.

Otoliths are organs used by fish for hearing and keeping balance. They consist of biogenic crystals of hydroxyapatite and do not contain any living cells. Upon exposure to ionizing radiation, otolith hydroxyapatite accumulates radiation-induced stable CO radicals whose amount is proportional to absorbed dose.

Application of the Ugi reaction for preparation of submicron capsules based on sugar beet pectin.

The Ugi four-component condensation in diluted liposomal suspensions was used to prepare pectin-based submicron capsules. A set of isocyanides and aldehydes was used to optimize the synthesis of capsule shells. Modified sugar beet pectin was selected as a natural polymer with pronounced surface activity to create a capsule shell.

Localization Mechanism of Interstitial Electronic States in Electride Mayenite.

Electrides contain interstitial electrons with the states that are spatially separated from the crystal framework states and form a detached electronic subsystem. In mayenite [CaAlO](e) interstitial electrons form a unique charge network where localization and delocalization coexist, pointing to the importance of investigating the many-body nature of electride states. Using density functional theory and dynamical mean-field theory, we show a tendency toward electron localization and antiferromagnetic pairing, which leads to the formation of an experimentally observed peak under the Fermi level.

Mechanosynthesis of High-Nitrogen Steels Strengthened by Secondary Titanium Nitrides.

The solid-phase mechanical synthesis of high-nitrogen ferritic and austenitic steel composites in the course of mechanical activation in a ball mill is studied by the method of Mössbauer spectroscopy and electron microscopy. For mechanical alloying, mixtures of iron alloys doped with transition metals (Ni, Cr, Mn, and Ti) and nitrides with low stability to deformation (CrN and MnN) were used. The correlation between the phase-concentration composition of the mechanically synthesized samples and the heat of formation of transition metal nitrides, which are part of the initial metal mixtures, is investigated.

Method to extracting the penetration field in superconductors from DC magnetization data.

The lower critical field, B, is one of the fundamental quantities of a superconductor that directly manifests the Cooper pair bulk density in the material. Although this field can be measured using several techniques, the most conventional method is to calculate this field from the experimentally measured DC penetration field, B, which is defined as the starting point of the deviation of the DC magnetization curve, M(B), from a linear dependence. Surprisingly, we found no mathematical routine that describes how this starting point of deviation can be found.

Prussian Blue Nanozymes with Enhanced Catalytic Activity: Size Tuning and Application in ELISA-like Immunoassay.

Prussian blue nanozymes possessing peroxidase-like activity gather significant attention as alternatives to natural enzymes in therapy, biosensing, and environmental remediation. Recently, Prussian blue nanoparticles with enhanced catalytic activity prepared by reduction of FeCl/K[Fe(CN)] mixture have been reported. These nanoparticles were denoted as 'artificial peroxidase' nanozymes.

Mechanical Behavior and Structural Characterization of a Cu-Al-Ni-Based Shape-Memory Alloy Subjected to Isothermal Uniaxial Megaplastic Compression.

For the first time, uniaxial megaplastic compression was successfully applied to a polycrystalline shape-memory Cu-Al-Ni-based alloy. The samples before and after uniaxial megaplastic compression were examined by methods of X-ray diffraction, optical, electron transmission, and scanning microscopy. The temperature dependences of electrical resistance and the mechanical properties of the alloys under uniaxial tension were also measured.

Computer vision spectrofluorometer-assisted detection of common nitro-explosive components with -type PAH-based chemosensors.

Computer vision (CV) algorithms are widely utilized in imaging processing for medical and personal electronics applications. In sensorics CV can provide a great potential to quantitate chemosensors' signals. Here we wish to describe a method for the CV-assisted spectrofluorometer-free detection of common nitro-explosive components, 2,4-dinitrotoluene (DNT) and 2,4,6-trinitrotoluene (TNT), by using polyaromatic hydrocarbon (PAH, PAH = 1-pyrenyl or 9-anthracenyl) - based -type chemosensors.

Rashba Spin Splitting in HgCdTe Quantum Wells with Inverted and Normal Band Structures.

In quantum wells (QWs) formed in HgCdTe/CdHgTe heterosystems with a variable composition of Cd(Hg), Shubnikov-de-Haas (SdH) oscillations are investigated to characterize the Rashba-type spin-orbit coupling in QWs with both a normal and inverted band structure. Several methods of extracting the Rashba spin-splitting at zero magnetic field and their magnetic field dependences from the beatings of SdH oscillations are used for greater reliability. The large and similar Rashba splitting (25-27 meV) is found for different kinds of spectrum, explained by a significant fraction of the p-type wave functions, in both the E1 subband of the sample with a normal spectrum and the H1 subband for the sample with an inverted one.

Synthesis of Nanocomposite TiSiCN Coatings by Titanium Evaporation and Organosilicon Compound Activation in Hollow Cathode Arc Discharge.

TiSiCN coatings have been obtained by anode evaporation of titanium and the decomposition of hexamethyldisilazane in an arc discharge, using a self-heated hollow cathode, at the pressure rate of 1 mTorr of the Ar+N gas mixture. The proposed method makes it possible to independently and widely change the amount of metal and precursor vapor flows, the pressure and composition of the vapor-gas mixture and the degree of ionic interaction on the surface of the growing coating within a single discharge system. The paper presents the method and the results of the effect of a current discharge (10-50 A), and the flux of precursor vapours (0-1 g/h), on deposition rates, compositions, and properties of TiSiCN coatings deposited by an advanced combined PVD+PECVD method.

Nanoscale Visualization of Photodegradation Dynamics of MAPbI Perovskite Films.

Herein, we report the nanoscale visualization of the photochemical degradation dynamics of MAPbI (MA = CHNH) using infrared scattering scanning near-field microscopy (IR s-SNOM) combined with a series of complementary analytical techniques such as UV-vis and FTIR-spectroscopy, XRD, and XPS. Light exposure of the MAPbI films resulted in a gradual loss of MA cations starting from the grain boundaries at the film surface and slowly progressing toward the center of the grains and deeper into the bulk perovskite phase. The binary lead iodide PbI was found to be the major perovskite photochemical degradation product under the experimental conditions used.

Novel cost-efficient protein-based membrane system for cells cocultivation and modeling the intercellular communication.

In vitro systems serve as compact and manipulate models to investigate interactions between different cell types. A homogeneous population of cells predictably and uniformly responds to external factors. In a heterogeneous cell population, the effect of external growth factors is perceived in the context of intercellular interactions.

Chemical Information in the L X-ray Absorption Spectra of Molybdenum Compounds by High-Energy-Resolution Detection and Density Functional Theory.

X-ray spectroscopy using high-energy-resolution fluorescence detection (HERFD) has critically increased the information content in X-ray spectra. We extend this technique to the tender X-ray range and present a study at the L-edge of molybdenum. We show how information on the oxidation state, phase composition, and local environment in molybdenum-based compounds can be obtained by analyzing the HERFD L X-ray absorption near-edge structure (XANES).

Theory of static magnetization of magnetopolymer composites: The second virial approximation.

This paper deals with a theoretical study of the static magnetization of a composite, consisting of nanodisperse single-domain ferromagnetic particles immobilized in a nonmagnetic medium. This situation is typical for magnetopolymer systems-smart materials, which found applications in high industrial and biomedical applications. It is supposed that the composite was polymerized without an external magnetic field; after curing the particles retain the spatial distribution and orientation of their axes of easy magnetization that they had before the host medium polymerization.

Critical Redistribution of Nitrogen in the Austenitic Cr-Mn Steel under Severe Plastic Deformation.

A narrow temperature range of changes in the mechanism and kinetics of structural-phase transformations during mechanical alloying under deformation in rotating Bridgman anvils was determined by the methods of Mössbauer spectroscopy, electron microscopy, and mechanical tests in the high-nitrogen chromium-manganese steel FeMnCrN. The experimentally established temperature region is characterized by a change in the direction of nitrogen redistribution-from an increase in the N content in the metal matrix during cold deformation to a decrease with an increase in the temperature and degree of severe plastic deformation. The change in the direction of nitrogen redistribution is due to the acceleration of the decomposition of a nitrogen-supersaturated solid solution of austenite with the formation of secondary nanocrystalline nitrides.

Photophysics, photochemistry and bioimaging application of 8-azapurine derivatives.

New 2-aryl-1,2,3-triazolopyrimidines were designed, synthesized, and characterized. Their optical properties were thoroughly studied in the solid phase, in solution and in a biological environment. Density Functional Theory (DFT) based calculations were performed, including the molecular geometry optimization for both the ground state and the first singlet excited state, the prediction of the UV-Vis absorption and fluorescence spectra, the determination of the molecular electrostatic properties and the solvent effect on the optical properties.

Water-Sulfuric Acid Foam as a Possible Habitat for Hypothetical Microbial Community in the Cloud Layer of Venus.

The data available at the moment suggest that ancient Venus was covered by extensive bodies of water which could harbor life. Later, however, the drastic overheating of the planet made the surface of Venus uninhabitable for Earth-type life forms. Nevertheless, hypothetical Venusian organisms could have gradually adapted to conditions within the cloud layer of Venus-the only niche containing liquid water where the Earth-type extremophiles could survive.

Modified Desolvation Method Enables Simple One-Step Synthesis of Gelatin Nanoparticles from Different Gelatin Types with Any Bloom Values.

Gelatin nanoparticles found numerous applications in drug delivery, bioimaging, immunotherapy, and vaccine development as well as in biotechnology and food science. Synthesis of gelatin nanoparticles is usually made by a two-step desolvation method, which, despite providing stable and homogeneous nanoparticles, has many limitations, namely complex procedure, low yields, and poor reproducibility of the first desolvation step. Herein, we present a modified one-step desolvation method, which enables the quick, simple, and reproducible synthesis of gelatin nanoparticles.

Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers.

We report results of comprehensive experimental exploration (X-ray photoemission, Raman and optical spectroscopy) of carbon nanofibers (CNFs) in combination with first-principles modeling. Core-level spectra demonstrate prevalence of sp2 hybridization of carbon atoms in CNF with a trace amount of carbon-oxygen bonds. The density functional theory (DFT)-based calculations demonstrated no visible difference between mono- and bilayers because σ-orbitals are related to in-plane covalent bonds.

Dendritic Iron(III) Carbazole Complexes: Structural, Optical, and Magnetic Characteristics.

This paper focuses on the synthesis, structural characterization, and study of the optical, magnetic, and thermal properties of novel architectures combining metal ions as magnetoactive centers and photoactive blocks formed by carbazole units. For this purpose, a series of azomethine complexes of the composition [Fe(L)]X (L = 3,6-bis[(3',6'-di--butyl-9-carbazol)-9-carbazol]benzoyloxy-4-salicylidene-N'-ethyl-N-ethylenediamine, X = NO, Cl, PF) were synthesized by the reaction of metal salts with Schiff bases in a mixture of solvents. The UV-Vis absorption properties were studied in dichloromethane and rationalized via time-dependent density functional theory (DFT) calculations.

Classifying Charge Carrier Interaction in Highly Compressed Elements and Silane.

Since the pivotal experimental discovery of near-room-temperature superconductivity (NRTS) in highly compressed sulphur hydride by Drozdov et al. ( , , 73-76), more than a dozen binary and ternary hydrogen-rich phases exhibiting superconducting transitions above 100 K have been discovered to date. There is a widely accepted theoretical point of view that the primary mechanism governing the emergence of superconductivity in hydrogen-rich phases is the electron-phonon pairing.

Effect of ring-shaped clusters on magnetic hyperthermia: modelling approach.

Experiments demonstrate that magnetic nanoparticles, embedded in a tissue, very often form heterogeneous structures of various shapes and topologies. These structures (clusters) can significantly affect macroscopical properties of the composite system, in part its ability to generate heat under an alternating magnetic field (so-called magnetic hyperthermia). If the energy of magnetic interaction between the particles significantly exceeds the thermal energy of the system, the particles can form the closed ring-shaped clusters.