Within the framework of our original approach, we have calculated the frequencies and intensities of normal vibrations of homobrassinolide and (22S,23S)-24-epibrassinolide molecules related to biologically active steroid phytohormones. Our approach combines the classic analysis of normal vibrations by the molecular mechanics method with the quantum-chemical estimation of absolute intensities. An interpretation of the absorption bands of the IR spectra is given on the basis of the comparison of the experimental and theoretical absorption spectra. An estimation of the impact of structural differences in the side chains of these molecules on the formation of their IR spectra in the region 1500-950 cm^-1 is obtained.

The structure and vibrational calculations of 5-chlorouracil (5-ClU) and its most stable dimer have been analyzed using the DFT method with B3LYP/6-31++G(d,p) and wb97xd/6-31++G(d,p), respectively. Vibrational calculations of the monomeric and dimeric forms were performed using both harmonic and anharmonic oscillator approximations with the same basis sets. A complete vibrational analysis of the molecule has been performed by combining experimental Raman, FT-IR spectral data and quantum chemical calculations. In addition, the DNA docking analysis of 5-ClU molecule was performed. 5-ClU molecule binds to the active site of DNA by hydrogen bonding interactions. The results show that the docked ligand formed a stable complex with DNA with binding affinity of -5.3 kcal/mol.

Тhe alignment of a liquid crystalline monomer by layers of photo-crosslinking polymers with a methacrylate backbone and photodimerized side groups is experimentally investigated. Polymers under investigation demonstrate the effect of a photostimulated alignment after rubbing with a cloth, like benzaldehyde polymers, but the required exposure dose of irradiation at 365 nm for them is smaller by two orders of magnitude due to the long-wavelength shift of the absorption spectra. The availability of high-power LEDs emitting at this wavelength opens the prospect of a multiple increase in the productivity of the process of alignment layers formation for liquid crystalline materials on the basis of polymers with the effect of a photostimulated alignment. It also becomes possible to effectively use lasers with a wavelength of 355 nm for aligning hologram recording.

The time kinetics of the optically induced anisotropy of molecular complexes with a nonequilibrium rotational distribution arising in the process of their formation in the gaseous phase is calculated. It is shown that damped periodic oscillations with the period and amplitude depending on additional angular moments appear in the relaxation kinetics of anisotropy.The additional angular moments are determined by the vectors of the moments of forces in the translational-rotational exchange, taking into account the law of the total angular momentum conservation of the molecules forming the complex. With an increase in their magnitude, the process of orientational relaxation of anisotropy becomes largely modulated. An estimation of the degree of optical anisotropy modulation and the moments of forces while the chemical bonds appear can be used to сlarify the stereo dynamics of the complex formation process.

A multivariate model has been developed for calibrating the content of flax oil in a binary mixture with unrefined sunflower oil using the optical density spectra in the UV, visible and near IR ranges. The proposed model, based on the principal component analysis, cluster analysis and the linear method of interval projection to latent structures, is characterized by a smaller root-mean-square error (0.12%) compared to the classical interpretable model (0.42%) and the multivariate model (0.63%) applying the full measured spectral range.

Sm³⁺ doped SrIn₂O₄ phosphors were prepared by a solution combustion method. The synthesized phosphors were characterized using powder XRD. The excitation and emission spectra of Sm³⁺ doped SrIn₂O₄ materials were analyzed at room temperature. SrIn₂O₄:Sm³⁺ phosphor emits 568-578, 606-617, 660, and 720 nm light under ultraviolet excitation of 300 nm. The photoluminescence properties of the synthesized phosphors with different Sm³⁺ doping concentrations were investigated. The optimum concentration of Sm³⁺ ion in SrIn₂O₄ was found to be 0.02 mol.

The 400 nm-thermoluminescence (TL) emission of UV (254.7 nm) irradiated Ca-rich carbonates of inorganic (aragonite) and biogenic (mollusc exoskeleton) origin is here reported. The samples exhibit complex glow curves, but (i) acceptable TL sensitivity when exposed to ultraviolet C (UVC) irradiation and (ii) stability of the UV-induced TL signal with initial rapid decay (ca. 70% for the aragonite and 40% for the biogenic carbonate) while maintaining the stability from 75 and 150 hours onwards. The dose response shows a significant scattered behavior up to 8 hours of UVC exposure, which may be associated with a combination of the phototransfer TL mechanism, the bleaching process, and the partially ionizing effect of the UVC irradiation.

X-ray luminescence spectra of β-Ga₂O₃ thin films obtained by radio-frequency (RF) ion-plasma sputtering in the temperature range of 80-300 K, were investigated. The measured spectra were simulated within the framework of the linear electron-phonon coupling model. On the basis of the temperature dependence of the selected luminescence bands, the associative nature of the selected luminescence centers with luminescence maxima at 2.95 and 3.14 eV is established, and the obtained results are analyzed.

The spectral-luminescent properties of water solutions of the 5,10,15,20-tetrakis-(3-N-methylpyridyl)-porphyrin at a temperature of 290±2 K are studied. The individual absorption and fluorescence spectra of atropisomers forming as a result of different orientations of the methylated nitrogen of pyridyl substituents relative to the mean plane of the tetrapyrrolic macrocycle are identified.

The effect of thermal nonlinearity (TN), on the characteristics of a nonlinear photoacoustic (PA) signal at the fundamental (FH) and second (SH) harmonics at its gas-microphone recording is investigated theoretically. The thermal nonlinearity is due to the temperature dependence of thermal parameters of the substrate, buffer gas and opaque sample as well as by the substrate emissivity. It is shown that the dependence of the amplitude of the FН on the frequency obeys the law ~w^-1/2 and for the SH the law is ~w^-3/2. The dependence of the amplitude of the FH on the intensity of the incident beam is expressed by the dependence of the temperature increment of the irradiated Q₀ and rear sides of the sample surface W₀ on I₀,while the same dependence for the SH is expressed by ~I₀².

Efficiency of the uniformly available approximation for description of the quantum Rabi model beyond the rotating wave approximation is systematically investigated. Correlation characteristics of the electromagnetic field in a resonator are calculated and some physical effects due to presence of the counter-rotating terms in the Hamiltonian are considered.

Optical transmission and reflection spectra of monocrystalline plates of zinc oxide (ZnO) implanted with 40 keV Co⁺ ions to high doses of (0.5-1.5)×10¹⁷ cm^-2 are presented. A decrease in the transmission value and the shift of the optical transmission edge to the long-wavelength region with increasing of the dose are observed in transmission spectra. Three absorption bands in the range of 550-680 nm are also observed in transmission spectra. The bands and their positions are typical for optically active Co²⁺ ions in the zinc cation substitution positions in the ZnO matrix. The reflection coefficient of the implanted side of the ZnO plate increases monotonously with the dose values. In both, the initial and implanted ZnO plates, a characteristic structure at λ = 375 nm due to exciton reflection is observed when recording the reflection spectra from the reverse (non-irradiated) side. Modeling of light transmission and reflection in cobalt-implanted ZnO samples was carried out within the framework of a three-layer model, in which the first surface layer contains cobalt nanoclusions, the second, deeper layer is a solid solution of cobalt ion substitution in the ZnO matrix, the third layer is the unradiated part of the ZnO plate. As a result of modeling, effective refractive indexes of two ZnO layers containing implanted cobalt admixture in different phase states were determined.

The possibility of using monocrystals of yttrium titanate in quantum electronics was considered. The optical zone melting technology for growing monocrystals of yttrium titanate doped with neodymium ions was developed. Absorption and luminescence spectra in the range from helium to room temperatures and laser generation were studied. Based on the analysis of spectroscopic data, a diagram of the energy levels of the Nd ³⁺ ion in the yttrium titanate lattice was constructed. It was shown that neodymium ions in the yttrium titanate lattice form two types of optical centers. The results of the study of laser generation in the pulsed mode at room and nitrogen temperatures are presented.

XFA procedure to determine a mass absorption coefficient in Cr/Co two-layer systems has been proposed. The procedure uses easy-to-make thin-film layers of sputtered chromium on a polymer film substrate. Correction coefficients have been calculated that take into account the absorption of primary radiation of the X-ray tube and the absorption intensities of the analytical lines of a lower layer element in an upper layer.

Practical aspects of modeling single-layer thin-film coatings for the interpretation of ellipsomet- ric measurements are considered. The restrictions imposed by the thickness of the skin layer and the measurement error on the number and parameters of the model layers are formulated. The presented theoretical conclusions are experimentally confirmed by studies of thin films of the La_0.7Sr_0.3MnO₃ and In₂O₃ compo-sitions.

The results of experimental studies of plasmon-stimulated transformation (conversion) of radiation polarization by Au gratings with different ratio between lattice period and excitation wavelength (including the first time investigated high-frequency gratings, for which the ratio of wavelength to period is close to 2), as well as with different modulation depth, are presented. Gratings for research are made by means of interference lithography using chalcogenide photoresists. The polarization conversion effect was studied by measuring the angular dependences (on the angle of incidence and azimuthal angle) of the specular reflection of linearly polarized monochromatic He-Ne laser radiation. It was found that for low-frequency gratings with a period more than wavelength and for the gratings with an intermediate frequency (grating period is a little less than wavelength), the maximum conversion efficiency for p-polarized radiation into s-polarized is reached at azimuth ~45° and is determined by the modulation depth. However, for high-frequency lattices on which surface plasmon-polaritons are excited at high incidence angles and azimuthal angles significantly less than 45°, the intensity of the resulting s-component is an order of magnitude less than for lower-frequency lattices. Thus, the efficiency of polarization conversion stimulated by the excitation of surface plasmons is determined not only by the lattice depth of modulation h/d, but also by the ratio of the exciting light wavelength to the lattice period λ/d.

He one-stage procedure using carbodiimide condensation was proposed for the controlled functionalization of water-soluble semiconductor quantum dots (QDs) with azide groups. A controlled variation in the surface density of the functional groups and zeta-potential was demonstrated by functionalization of anionic (carboxylic) and similar zwitterionic polymer-encapsulated CdSe/ZnS core-shell QDs. Ethanolamine-O-sulfate (EOS), aminotetraethylene glycol (H₂N-[TEG]-OH) and aminotetraethylene glycol azide (H2N-[TEG]-N₃) were utilized as modifiers. Functionalization was investigated by studying the kinetics of the organic dye JOE conjugation with QDs using the strain-promoted azide-alkyne cycloaddition (SPAAC) reaction. The reactivity of QDs towards SPAAC has been found to be nearly proportional to the relative density of the surface azide groups, and the QDs zeta-potential correlates with the ratio of the modifiers. It was shown that azido groups on the surface of QDs can be easily and under mild conditions transformed into primary amino groups using tris(2-carboxyethyl)phosphine (TCEP) as a reducing agent. The applicability of surface-functionalized QDs for bioconjugation was demonstrated by their conjugation with dye-labeled bovine serum albumin (BSA).

In order to quantitatively detect hydrogen polysulfides (H₂S_n, n > 1) in biosystems, we propose a new two-photon turn-on fluorescent probe, named N_p-S_n, based on the D-π-A skeleton two-photon fluorophore of 4-hydroxy-1,8-naphthalimide derivative and deprotection of 2-fluoro-5-nitrobenzoic ester by H₂S_n. N_p-S_n displayed a more than 80-fold enhancement towards H₂S_n in 550 nm and high sensitivity with a detection limit as low as 33 nM. Additionally, the probe N_p-S_n was further used for fluorescence imaging of H₂S_n in living cells under two-photon excitation (820 nm), which showed a high-resolution imaging, thus demonstrating its practical application in biological systems for the study of physiological and pathological functions of H₂S_n.

This study combined Raman technology and nanotechnology to detect periodontal inflammatory factors. We synthesized silver nanoparticles and made modifications to their surface to produce Ag NP-antibody probes. A sandwich immunoassay was developed for the sensitive detection of TNF-α and IL-1β. SERS intensity showed a good linear relationship with TNF-α and IL-1β concentrations in our study. The results of detection of these biomarkers in GCF indicate excellent specificity, high sensitivity, and great reproducibility of this immunoassay. Our immunoassay based on the SERS technique would facilitate clinical diagnoses of periodontal diseases.

The effect of phytoplankton “bloom” on the change with depth of photosynthetically available radiation (PAR), the spectral downwelling irradiance in costal waters and the phytoplankton ability to absorb PAR in the sea is estimated. A tenfold increase in the chlorophyll a concentration (from 0.4 to 4.0 mg/m³) during the diatom/dinoflagellate “bloom” leads to a decrease in water transparency and a narrowing of the photosynthesis zone, and, consequently, to almost twofold decrease in the average PAR within the layer of phytoplankton existence. The diatom/dinoflagellate “bloom” is accompanied by a change in the spectral features of the downwelling irradiance at the same level of PAR (optical depths): near the bottom of the euphotic zone the maximum of penetrating irradiance shifts to the longer wavelength part (~550-600 nm) compared to background conditions (~500-550 nm). An increase in the biomass of diatoms/dinoflagellates and the concomitant change in the spectral characteristics of downwelling irradiance are accompanied by a decrease in spectrally weighted chlorophyll a specific absorption coefficient by phytoplankton pigments up to ~3 times in comparison to background condition at the same optical depths. When coccolithophores “bloom”, the spectral downwelling irradiance at fixed optical depths and the ability of cells to absorb light change slightly compared to background conditions.

The methodology of integrated ground-based and satellite monitoring of atmospheric aerosols is discussed, and an algorithm for processing data from coordinated lidar and radiometric measurements (LRS) is described. The algorithm was tested to study the altitude profiles of the aerosol parameters in the vicinity of the AERONET stations using data from ground-based solar radiometers and the CALIOP satellite lidar. To verify the results of satellite sensing, coordinated measurements with AERONET network radiometers and ground-based multi-wavelength lidars at the remote sensing stations of the Institute of Physics, NASB (Minsk, Belarus), Institute of Atmospheric Optics, SB RAS (Tomsk, Russia) and KRSU (Teplokluchenka, Kyrgyzstan) were used.

This paper reports the open path measurement of atmospheric transmission in the spectral region of 3000-3450 nm using a mid infrared tunable lidar in New Delhi (28.7°N, 77.1°E), India. Results on the measurement of atmospheric transmission in New Delhi are reported for first time, to the best of our knowledge. A tunable infrared lidar system has been developed in-house, which transmits laser radiation with the wavelength interval of 1 nm in the above spectral band into the atmosphere. A 200 mm diameter Cassegrain receiver telescope with mercury cadmium telluride (MCT) detector is used to collect the backscattered radiation from the atmosphere. The reflected laser radiation received from the tower located at a distance of 400 m is used to generate the transmission spectrum. Data recorded during the daytime measurements have been considered in this paper. Transmission spectra measured over several days showed a similar pattern, which confirmed the repeatability of the system performance. The measured spectra are also compared with the SkyCalc transmission model generated using the online database. Preliminary analysis indicated that these spectra had good agreement in general with a small shift in wavelength region. We have also analyzed the HITRAN database line-by-line and identified the possible major absorbing molecules in this band. The sources of air pollutants that absorb in this band and also discussed.

The features and problems of main approaches for measuring laser frequency noise are analyzed. A method is proposed, in which an unbalanced fiber-optic interferometer is used. At the output of the interferometer, a sub-carrier frequency signal modulated by laser frequency fluctuations is formed and the signal spectrum is measured. The proposed approach is relatively simple and affordable and does not require the use of rare specialized devices and complex specific procedures.

Geometrical structure, electronic and optical properties, electronic absorption spectra, vibrational frequencies, natural charge distribution, thermodynamic properties, and MEP analysis of trans- and cis-structures of Flupentixol have been investigated using DFT and TDDFT methods with the B3LYP hybrid functional and 6-311+G^** basis set. The results of calculation of the quantum properties verify the greater activity of the cis structure of this drug.

In this article, the stability of the conformers of 2-chloro-3-methylcyclohexan-1-one oxime was investigated at the wB97XD/6-311G(d,p) level of theory. Using the self-consistent reaction field theory (SCRF) based on the Polarizable Continuum Model (PCM), the solvent impacts were examined. Solvent influence on the total energy, relative energy, dipole moment, the energies of frontier orbitals, and proton chemical shift of these molecules was investigated. The associations between these parameters and solvent polarity functions including both the dielectric constant (e) and refractive index (n_D) of the liquid medium were found. Moreover, NBO analysis was used to illustrate the hyperconjugative anomeric effect on the conformers.

We present a testing method based on the use of wavelength-indirect broadband optical monitoring. A polarizing beam splitting (PBS) coating applied at a wavelength of 1550 nm at an incidence angle of 45° was designed. The optimized coating structure contained 59 non-quarter-wave (QW) layers. Preproduction error analysis was used to estimate the advantages of the application of wavelength-indirect broadband optical monitoring. Then, we deposited the PBS coating with an optimized monitoring strategy by ion beam sputtering (IBS). Finally, reverse engineering of the produced PBS coatings was executed. The experimental results show that a good agreement between the theoretical target and the measured transmittance is obtained, the maximum error in the first and last two layers is about 10%, and the minimum error is only about 0.01%.

Porous ceramic material is widely used in a great deal of fields. In this work, porous alumina ceramics with micron open cells are modeled by applying the inverse opal structure. The considered porous alumina ceramics are periodic with different size parameters. The diameters of spherical pores are 200, 400, 600, and 800 nm, while the ratios of height to diameter range from 0.1 to 0.9. The absorptivity, transmissivity, and reflectivity for the wavelength range from 0.2 to 2 μm are calculated using the finite difference time domain (FDTD) method. Then the effects of size parameters and incident angle on the optical properties are discussed. The results show that the absorptivity is usually very small. For the transmissivity, a wide dip in the transmission spectrum appears when the diameter and height exceed the critical values, and a red shift of the transmission spectrum’s wide dip with increasing height is observed. When the incident wavelength is longer than the critical wavelength, the spectral transmissivities of porous ceramics with a certain diameter reach a stable domain. Moreover, the red shift of the wide dip, the critical incident wavelength, and the critical ratio of height to diameter are visibly affected by the size parameters and the incident angle.

А distinctive fluorescent probe based on 2-(3-aminopropyl) isoindoline-1, 3-dione (probe 1) has been developed and synthesized. Probe 1 was applicable for sensing lead ion in C₂H₅OH with high binding constant (1.1×10⁷ M^-1) and sensitivity down to 3.47 μM (3/slope) (limit of detection). The linear response was determined to be in the range of 0-9.0 μM. These results demonstrated highly selective and sensitive detection for lead ion of probe 1.