It is shown that based on the fundamental propositions of the theory of molecular spectra (energy levels and transition probabilities), one can build a system of equations describing not only intramolecular processes (temporal changes of spectra) but chemical transformations, too. To this end, we introduce resonant levels the wave functions whereof describe the chemical transformations and allow to evaluate their ab initio probabilities. As a result, one has a possibility to conduct computer experiments with the prognostic aim for investigating the process development and its optimization.

Various methods have been developed and compared for determining the concentration of hydroxyl groups in oligomers on the basis of azidesubstituted oligooxetane diols. The IR spectroscopic express method is the most convenient for substituted azidesubstituted oligooxetane diols. The advantages of this method are its high precision, good reproducibility, fast analysis, and low sensitivity to moisture. The principles underlying the developed methods are suitable for the development of other methods for determining the content of hydroxyl groups in oligomers and polymers of different chemical nature.

J-aggregation of the anionic oxacarbocyanine dye 3,3¢-di-(γ-sulfopropyl)-5,5’-diphenyl-9-ethyloxacarbocyanine betaine is studied in aqueous solutions in the presence of proteins (collagens, immunoglobulin G, serum albumins) and polyelectrolytes (polyethylenimine, polyvinylpyrrolidone). It has been found that the denaturation of human serum albumin by urea stimulates J-aggregation of the dye. In the presence of denatured albumin and polyethylenimine, the dye forms J-aggregates of two types. The J-aggregates formed in the presence of polyethylenimine undergo rearrangement with time.

A sensitive and selective surface-enhanced Raman scattering (SERS) sensor for mercury(II) was fabricated based on the target-mediated displacement of a T-rich oligonucleotide strand. A DNA/aptamer duplex was prepared by the hybridization between a tetramethylrhodamine(TMR)-labeled thymine(T)-rich Hg²⁺ -specific aptamer (denoted as TMR-aptamer) and a thiolated adenine-rich capturing DNA. The duplex can be immobilized onto the SERS substrate of the Ag-moiety modified glycidyl methacrylate-ethylene dimethacrylate (denoted as Ag-GMA-EDMA) via self-assembly by the thiol anchor, in which the TMR-aptamer exists in a double-stranded chain. In this case, the label of the TMR moiety approaches the substrate surface and produces a strong SERS signal. Upon the addition of the target, a pair of TMR-aptamers could cooperatively coordinate with Hg²⁺ to form a stable duplex-like structure mediated by the T-Hg²⁺ -T complex between two adjacent strands, which triggers the release of the TMR-aptamer from the SERS substrate surface, thus drawing the TMR tags away from the substrate with a significant decrease in the SERS signal. This optical sensor shows a sensitive response to Hg²⁺ in a concentration from 5 nM to 2.0 mM with a detection limit of 2.5 nM. The prepared sensor is negligibly responsive to other metal ions, can be easily regenerated and shows good performance in real sample analysis.

The complex formation and extraction of anionic chelates of Co(II)-4-(2-thiazolylazo)resorcinol (TAR) with cations of monotetrazolium salts (TS) - (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and 3-(2-naphthyl)-2,5-diphenyl-2H-tetrazolium chloride (TV) - in the liquid-liquid extraction system Co(II)-TAR-TS-H₂O-CHCl₃ were studied by spectrophotometric methods. The optimum conditions for the extraction of Co(II) were found. The molar ratio of the components and the form of the anionic chelates of Сo(II) in the extracted compounds were determined by independent methods. The association process in the aqueous phase and the extraction process were investigated and quantitatively characterized. The following key constants were calculated: association constant, distribution constant, extraction constant, and recovery factor. The validity of the Beer’s law was checked, and some analytical characteristics were calculated. Based on the obtained results and the lower price of the monotetrazolium salt MTT compared with that of TV, the ion-associated complex of Co(II)-TAR-MTT can be implemented for determination of cobalt(II) traces in alloys and biological, medical, and pharmaceutical samples.

We have prepared a series of¹²CO₂/¹³CO₂ binary mixtures as standard samples at room temperature. Using micro-laser Raman spectroscopy, it was found that the relationship between the¹²CO₂ mole fractions and the peak area ratios of¹²CO₂/¹³CO₂ in the Raman spectra of CO₂ binary mixtures showed a polynomial correlation. The establishment of the experimental working curve paves the way for estimating the mole fractions of each individual fluid inclusion and determining¹³C/¹²C and δ¹³C using micro-Raman spectroscopy. The Raman spectra of¹²CO₂ and¹³CO₂ showed a characteristic peak at 1348 cm^-1 with an argon laser at 785 nm, which is perhaps due to the formation of dimers.

The absorption, fluorescence, and excitation spectra of FHC and THC have been studied and compared with 3HF in cyclohexane, acetonitrile, and methanol. Anion formation in acetonitrile and methanol has been observed in all three flavonols in the order THC-FHC-3HF in their ground states. As excitation and absorption spectra are similar in all the cases (including the anion one), it is possible to observe the absorption spectra of the pure anion of the flavonols in neutral solvents, which is difficult to measure directly.

The cathodoluminescent (CL) properties of Y₂O₃:Eu thin films obtained by RF magnetron sputtering were investigated. Based on the dependence of CL spectra on the energy and current density of the electron excitation, the increase of the number of Eu³⁺ ions in a state of low symmetry C₂ deep in the film relatively to the surface was suggested. The dependences of the CL intensity on the energy of the exited electrons and the current density of electron irradiation were established. The influence of the structural heterogeneities of the films and the excitation conditions on the kinetic characteristics of the red luminescence of Y₂O₃:Eu in the region of 612 nm due⁵D₀-⁷F₂ electric dipole transition was shown.

The spectral dependences of the imaginary parts of dielectric permittivity ε₂ (E), volume (-Imε^-)¹ and surface (-Im(1+ε)^-1) characteristic losses of the electron energy of barium selenide are decomposed into 34 elemental components for the energy ranges from 3 to 5.5 eV at 2 K and from 5.5 to 26 eV at 77 K through the modified method of Argand’s united diagrams. For each band of the spectra of three types the values of energy maximum E_i , half-width H_i , amplitude I_i , square S_i , and oscillator strength f_i were determined. The f_i parameter was calculated using the modified formula known for the effective number of valent electrons n_eff(E). The features of 34 elementary bands of barium selenide in the range from 3 to 26 eV caused by the excitons and interband transitions of transverse and longitudinal types were established.

The spectral-kinetic features of the optical conversion of electronic energy during the dipole-dipole transfer of electronic excitation between the silver (Ag) sol nanoparticles (NPs) of small and medium size and rhodamine 6G molecules on the macroporous silica (C-80) surface with an irregular pore structure. It was found that the sorption of Ag NPs on the C-80 surface is uneven with islet-type distribution of clusters of Ag NPs having different sizes. Threshold gain of the light scattered by the surface plasmons was detected at a certain concentration of Ag NPs on silica. Quantitative evaluation of the local plasmon excitations in clusters of Ag NPs on silica was carried out.

It is shown that in Ge/Si quantum nanoheterostructures, two germanium dots can be treated as excitonic quasi-molecule on the surfaces of which excitons (consisting of spatially separated electrons and holes) are localized. The effect of a significant increase in the binding energy is found for the ground singlet state of an excitonic quasi-molecule in a nanoscale system as compared to the biexciton binding energy in the silicon single crystal. It was found that the main contribution to the binding energy of the quasi-molecule comes from exchange interaction between electrons and holes, which is significantly greater than that of Coulomb interaction between electrons and holes.

The samples of sphero-conical vessels massively represented in the Bulgarian ancient settlement were analyzed by Mössbauer spectroscopy. Wares with relatively low annealing temperature <500°C and having relation /Fe²⁺ ≤1.11 in the transmission spectra were differentiated from the wares with high annealing temperature. The detected value of /Fe²⁺ is much less than the value of 2.69, which characterizes the raw materials for pottery production in the vicinity of the selected settlement. This fact indicates the existence of other non-localized sources of raw materials of the medieval handicraft center.

The model of the autofluorescence spectrum formation of crystalline lens taking into account light scattering was presented. Cross sections of extinction, scattering and absorption were obtained numerically for models of normal crystalline lens and cataract according to the Mie theory for polydisperse systems. To validate the model, data on the autofluorescence spectra of the normal lens and cataracts were obtained using an experimental ophthalmologic spectrofluorimeter with excitation by UV light emitting diodes. In the framework of the model, the influence of the lens light scattering on the shape of the luminescence spectrum was estimated. It was found that the changes in the fluorescence spectrum of lenses with cataracts can be completely interpreted by the light scattering.

The time-resolved fluorescence anisotropy decay of perylene incorporated into the lipid L-α-dipalmitoylphosphatidylcholine (DPPC) membrane has been studied to evaluate the membranotropic action of non-steroidal anti-inflammatory substance ibuprofen and the joint effect of ibuprofen and cholesterol. The obtained values of rotation correlation times (j) and limiting anisotropy (r_∞) allow estimating independently the effects of these additives on microviscosity and ordering of model lipid membranes in different phase states. Ibuprofen is shown to decrease significantly the DPPC membrane microviscosity in the gel phase with no actual effect in the liquid-crystal phase. However, in both phases ibuprofen decreases the ordering of the lipid hydrophobic chains. When ibuprofen is embedded in a lipid membrane enriched with cholesterol, a pronounced additive effect is observed in the gel phase manifesting itself in substantial dilution and disordering of the lipid membrane by the components. In the liquid-crystal phase, ibuprofen causes leveling of the densifying and regulating effects of cholesterol.

The statistical relationship between the sensor Landsat data and chlorophyll concentration in the waters of the Ivankovo reservoir was studied. Regression relationship that describes the dependence of the pixel values of satellite images on in situ chlorophyll concentration measurements in water (using electron microscopy) and allows analyzing the spatial distribution of chlorophyll concentration in the reservoir was found. Trophic status, amount of phytoplankton biomass and primary production were estimated based on the chlorophyll concentration data.

The fast algorithm is proposed for retrieving the atmospheric water vapor maps from multi-spectral images of the Earth captured by Ocean and Land Colour Instrument (OLCI) onboard European research satellite Sentinel-3. The algorithm is based on the multiple regressions between top of atmosphere spectral reflectance, geometrical parameters of satellite scene (solar and view angles) and total water vapor content in atmosphere. The regression equation is derived from the Monte-Carlo radiative transfer model taking into account experimental data on the variability of optical characteristics of the atmosphere and underlying surface. The equations includes top of atmosphere reflectance in near-IR water and oxygen absorption channels together with atmospheric transparent window channels of OLCI to exclude the impact of the surface spectral reflectance and the ground air pressure on the accuracy of atmospheric water vapor remote sensing. The algorithm has been tested on the data of OLCI prototype - Medium Resolution Imaging Spectrometer (MERIS). An ability of the developed algorithm to retrieve of the water vapor spatial distribution without the need for subsatellite data and digital elevation models is shown with an example of MERIS images for the territory of East Europe. A good correspondence is achieved between the MERIS and AERONET (Aerosol Robotic Network) data (standard deviation of integrated water vapor 1.24 kg/m²).

The soil of two agricultural sites near an industrial area was investigated for heavy metal pollution using energy dispersive X-ray fluorescence (EDXRF). The concentration values for 17 elements were determined in the soil samples including eight heavy metal elements, i.e., Fe, Ni, As, Pb, Mn, Cr, Cu, and Zn. The soil near a pulp and paper mill was found to be highly polluted by the heavy metals. The concentration data obtained by EDXRF were further examined by calculating the pollution index and Nemerow integrated pollution index.

The single- and multilayer coatings of micro- and nanocrystalline diamond were deposited on cemented carbide substrates (WC + 6 wt.% Co alloy) in a microwave plasma of methane-hydrogen and methane-hydrogen-nitrogen mixtures. The barrier tungsten layers were used to improve adhesion of the diamond coatings on the substrates. Raman spectroscopy was used to study properties of the nano- and microcrystalline diamond coatings depending on the deposition parameters. Data on structural transformations of the coatings under different tribological contact conditions were obtained, and the secondary nucleation processes on different diamond faces during the deposition from the gas phase were investigated.

We have considered collinear and orthogonal configurations of double-pulse laser-induced breakdown spectrometry (LIBS) for the chlorine determination in plants and concrete by Cl I 837.59 nm line. It has been found that the signal-to-noise ratio is slightly lower in the orthogonal configuration due to spatial instability of the second breakdown. At the same time, the suppression of interfering molecular bands in this case can increase the LIBS sensitivity of chlorine analysis in plant materials.

X-ray fluorescent signals of F K_a, Na K_a, Cl K_a, K K_a, and Ta L_a were measured by WD-XRF for various fluorine-containing systems: K₂TaF₇, Na₃AlF₆, K₂ZrF₆, NaF, and LiF (with NaCl and wax as additional additives). The data were recorded for 41 samples (in the form of pellets prepared in the laboratory) by more than 200 scans. The analysis of the measured fluorine X-ray fluorescence intensities demonstrated that the balance between absorption and enhancement effects depends strongly on the presence and concentration of other elements in the system. The experimental intensities of X-ray fluorescent radiation of fluorine for different systems with comparable fluorine content could differ by as much as 500%.

The photo-oxidative degradation of polyurethanes based on hexamethylene diisocyanate with oligoether parts of different types has been investigated by means of IR-spectroscopy and dynamical mechanical analysis. High density cross linked polyurethane based on oligo-ether triol of molecular mass 500 has been found to possess a tendency to the crosslinking density growth under photooxidation. The polyurethane, containing ester groups has been shown to be more stable, compared to the polyurethane based on oligoether diol of similar molecular mass.

The effect of collisions of gas particles changing the velocity direction on reproducing information in a stimulated echo hologram response is discussed. As a result of such collisions, frequency shifts in the emission of the gas atoms change randomly (spectral diffusion within an inhomogeneously broadened line). It has been shown that this leads to uncorrelated inhomogeneous broadening in the gas at different times and to a partial loss of the phase memory resulting in a partial loss of reproducible information which was encoded in the temporal form of the object laser pulse.

Synchrotron X-ray radiolysis-induced redox in a chromium aqueous solution was monitored using in situ X-ray absorption spectroscopy. The radiolysis in the fluid sample within a specifically designed hydrothermal diamond anvil cell caused the oxidation of Cr(III) to Cr(VI) upon heating from room temperature to 400^oC, and reduction of Cr(VI) to Cr(III) at 500^oC. The two fitted components of the pre-edge features of the Cr K-edge spectra were used to identify the presence of Cr(VI) in the solution.

Terahertz spectroscopy combined with weighted discriminate analysis (WDA) is performed with different transgenic cottons (HD-1, HD-73, and Coker 312). The time-domain spectra of the samples are transformed into frequency-domain spectra by using fast Fourier transform. Then the absorbance curve of the samples is obtained. By applying the absorbance data in conjunction with the WDA model, the identification rates of the different transgenic cottons are 89.4, 89.7, and 92.5%, respectively. The experimental results demonstrate that THz spectroscopy combined with WDA is a novel and feasible way to detect transgenic cottons.

The energy levels, wavelengths, transition rates, and line strengths have been calculated for the 4s²4p²-4s4p³ and 4s²4p²-4s²4p4d allowed transitions occurring within the ground configuration (4s²4p²) in the heavy Ge-like Te, Xe, and Ba ions. The fully relativistic multiconfiguration Dirac-Hartree-Fock method taking into account both correlations within the n = 5 complex and the QED effects has been used in the calculations. The calculation results are found to agree well with the data obtained on the TFR tokamak and by recent EBIT measurements in Xe. The isoelectronic sequence of the Ge-like ions is important in nuclear fusion research as their spectra may provide diagnostic information on magnetically confined plasmas.

The purpose of this paper is to study the feasibility of fluorescence spectroscopy as a reliable method for discrimination of Chinese liquor according to different aroma styles and geographic origins. The 84 Chinese liquors were analyzed by fluorescence spectroscopy and chemometrics. The results showed that Chinese liquors exhibit characteristic fluorescence spectra recorded at special excitation wavelengths that may be considered as fingerprints. Both principal component analysis (PCA) and stepwise linear discriminant analysis (SLDA) were carried out on the emission spectra (330-435 nm) recorded at excitation wavelength 300 nm to classify different aroma styles of Chinese liquors. The first two principal components explained 98.87% of the total variance, and the SLDA classified correctly 100%. Both hierarchical cluster analysis (HCA) and principal component analysis (PCA) were carried out on the emission spectra (325-420 nm) recorded at excitation wavelength 300 nm to identify different geographic origins of Chinese liquors. HCA accurately identified all the samples and the first three PCA explained 98.25% of the total variance. This study indicates that fluorescence spectroscopy coupled with chemometrics offers a promising approach for identifying Chinese liquors according to different flavor types and geographic origins.