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Zhurnal Prikladnoii Spektroskopii

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Vol 85, No 4 (2018)
525-531 266
Abstract
The Raman spectrum of polycrystalline triphenylmethane (TPhM) is recorded at room temperature in the range 4000-400 cm- 1 . The optimal structure and the vibrational spectra (Raman and IR) of TFM have been calculated in the B3LYP/6-311G (d, p) approximation. On the basis of visualization of vibrations, the theoretical modes and the corresponding experimental bands of the Raman spectrum are assigned to the valence and deformation vibrations of certain bonds in the TFM molecule. Most bands and, in particular, the most intense bands in the Raman spectra of TFM are due to vibrations in monosubstituted benzene rings. Some of the theoretical modes and the corresponding experimental bands are assigned to benzene modes in Wilson notation.
532-537 303
Abstract
Results of spectrophotometric research of the association of ethidium bromide and caffeine molecules in aqueous solution are presented. Experimental data were analyzed using a dimer model of heteroassociation of molecules. Numerical values of the equilibrium constants of association of molecules were defined. The experimental spectrum of absorption of a mixture of heterocyclic molecules was decomposed into individual components using the regularization method. Quantitative information on the heterocomplex structure based on the individual spectrum components was obtained - the distance and the angle between the point dipole moments of the transitions of heterogeneous molecules are 0.3 nm and 16°. Calculation of the relative content of different types of associates in a mixed solution shows that heteroassociation of molecules leads to a decrease in the effective concentration of ethidium bromide and, accordingly, to a lesser mutagenic activity of a dye.
538-544 299
Abstract
The state of water in hydrogels of sodium carboxymethyl cellulose and bentonite was studied by low-temperature1H NMR spectroscopy. It was established that polymer macromolecules actively interact with bentonite. Thermodynamic parameters of the layers of strongly and weakly bound water, as well as the interphase energy of the water in hydrogels were determined.
545-549 554
Abstract
Luminescence spectra of He, Ne, Ar, Kr, Xe and Ar-Kr, Ar-Xe, Kr-Xe mixtures in the range of 200-970 nm were investigated under the electron beam excitation with the duration of 5 ns. Distribution of emission intensity over 2p-levels of noble gas atoms was obtained. It was concluded that dissociative recombination of molecular ions of noble gases with electrons was not the main process of population of atomic levels. The intensity of radiation of heteronuclear ionic molecules of noble gases (relatively to the intensity of atomic lines) was significantly lower than in the case of excitation by the ion beam.
550-556 374
Abstract
Fluorescence quenching of four dyes (acridine orange (AO), rhodamine B (Rd B), rhodamine 110 (Rd 110), and rhodamine 640 (Rd 640)) by colloidal graphene oxide (GO) was investigated in phosphate buffer solution (pH 6.0). Dynamic and static quenching processes were analyzed with the use of the Stern-Volmer equation. From the studied dyes, static quenching by graphene oxide was observed in AO, Rd 640, and Rd B, while mixed dynamic and static quenching was characteristic for the Rd 110 compound. The Stern-Volmer constant of dynamic quenching is ten times smaller than for the static quenching. The association constants of the dyes with GO are located in the series 2540 (АO) > 495 (Rd640) > 260 (Rd110) > 144 l/g(RdB). The value of the π-π stacking interaction is strongly influenced by the phthalic fragment oriented perpendicular to the xanthene in rhodamine dyes, as well as by four alkyl groups in Rd B due to their torsional oscillations and rotational motions.
557-561 249
Abstract
The method of Raman spectroscopy is used to obtain in situ information on the interparticle interaction features Raman spectroscopy is used to obtain in situ information on the interparticle interaction features in the high-temperature disperse system Li2CO3-Na2CO3-K2CO3 melt-MgO nanopowder. This information is required to find the optimal operating environments for carbonate fuel cells. It is found that when magnesium oxide nanopowder is introduced into the carbonate melt, a change in the vibrational spectrum of the system occurs due to the solvation of the solid-phase particles by the ions of the salt melt.
562-569 270
Abstract
The color change and chemical behavior of Madagascar dravite when subjected to heating in air atmosphere were studied by energy-dispersive X-ray fluorescence spectrometry, UV-visible (UV-vis) spectroscopy and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Heat treatment was performed with temperatures of 500, 600, and 700oC for 2 h. Colors and color differences were measured and evaluated using CIELAB color measurement. The origin of color and its change after treatment are assessed via UV-vis spectra. The diffuse reflectance infrared spectra of the dravites revealed major absorption bands of OH, BO3, Si6O18, and R-OH (where R = Fe, Mg). The variation of infrared spectra with increasing temperature indicates the deformation of R-OH bonds in an octahedron and, further, the deformation of BO3 and Si6O18. The results of color change may be utilized to enhance the color or clarity in dravite tourmaline and for generating satisfactory color.
570-575 233
Abstract
The results of the optical properties investigations of metallic cerium in the liquid and solid film state are presented. The optical constants are measured by the ellipsometric Beattie method in the range 0.42-2.6 μm at room temperature. Based on the measured refractive indexes and the absorption coefficients, the light conductivity σ, reflectivity R, and characteristic loss function Imε- 1 are calculated. On the basis of the experimental measurements in the IR region, we have calculated the electronic characteristics of liquid cerium and its polycrystalline film and their relation with the electrical conductivity
576-583 310
Abstract
The spectra of 16 optical Mg2Si functions in the range from 0 to 11 eV at 77 K are determined. They contain five maxima and shoulders due to interband transitions and metastable excitons, as well as the maxima of volume and surface plasmons at ~9.56 and ~7.30 eV. Their peculiarities and general regularities are established. The calculations are performed on the basis of the well-known experimental reflection spectrum in the range from 0 to 11 eV at 77 K. The integral spectra of the imaginary parts of the permittivity ε2(E), characteristic volume (-Imε-1), and surface (-Im(1+ε)-1) energy losses of electrons are decomposed into elementary components in the region from 2 to 5 eV. Their main parameters are determined, including the energy of the maxima and the strength of the oscillators. The calculations are carried out using computer programs based on the Kramers-Kronig relations and known analytical formulas for the connection between optical functions, as well as an improved nonparametric method of combined Argand diagrams taking into account the effective number of valence electrons participating in the formation of individual bands. Instead of the five maxima and shoulders of the integral spectra, 17 elementary bands with oscillator strengths in the range from 0.0003 to 1.92 are established. They are due to excitonic and interband transitions of the transverse and longitudinal types. On the basis of known theoretical calculations, we propose herein the localization and assumed nature of the optical transition bands.
584-591 218
Abstract
Conjugates of metal hydroxyl phthalocyanines (М(ОН)nРс; М = Si, Ge, Al, Ga) with 3-aminopropyltriethoxysilane (APTEOS) are synthesized. By means of the sol-gel method, polymeric silicate gel materials doped with the (APTEOS)n-М(ОН)nРс conjugates are prepared: the latter form structural links in the composition of the copolymer with the siloxane fragments of the polymeric chains (in the case of n=2) or are “grafted” to such chains in the form of side substituents (n = 1). It is shown by the spectral-luminescent methods and the methods of kinetic spectroscopy that the (APTEOS)n-М(ОН)nРс conjugates, on the introduction into a silicate gel material, retain their molecular structure and the photophysical characteristics of MPcs in the monomeric form. The obtained macromolecular substances are promising as monomeric dopants in new functional materials for optics and quantum electronics.
592-599 261
Abstract
The effects of laser wavelength and argon ambient gas pressure on ionic and atomic emission from aluminum and copper metal plasmas has been studied. The plasmas were generated using metal targets excited with a Q-switched Nd:YAG laser operating at the first fundamental (1064 nm), second (532 nm), third (355 nm), and fourth harmonics (266 nm) with repetition rate up to 10 Hz. The spectroscopic analysis of the plasma plume emission revealed that the intensities and signal-to-noise (S/N) ratio of various neutral and ion spectral lines, small components, and trace impurities increase sharply when the fourth laser harmonic is used at a wavelength of 266 nm. Based on LTE assumption, the electron excitation temperature (Te) and electron number density (Ne) of the produced plasma have been estimated from the Boltzmann plot using neutral spectral lines of Al I at 256.8, 257.5, 309.3, and 396.15 nm and Cu I at 427.58, 510.59, 570.07, and 578.58 nm and from Stark broadening width profile of Al II at 281.6 nm and Cu I at 324.75 nm, respectively. The variations of Te, Ne, and emission intensities of metals as a function of laser irradiance of different laser wavelengths at 1064, 532, 355, and 266 nm were studied. The effect of the argon ambient gas pressure on the plasma parameters was also studied. The diagnostic of the produced metal plasma was undertaken using laser induced breakdown spectroscopy (LIBS).
600-605 222
Abstract
Laser-induced breakdown spectroscopy (LIBS) has been applied to measure spectral characteristics and for a quantitative analysis of the concentration of phosphorus (P) in compound fertilizer, an issue of great concern for the fertilizer industry. For analysis using LIBS, fertilizer samples were compressed into pellets and a pulsed Nd:YAG laser was employed to produce the plasma in air and argon (Ar) atmospheres. Using this approach, we analyzed the time evolution characteristics of the P analytical line in air and Ar atmospheres. Calibration curves were constructed for measurements under air and Ar atmospheres using reference fertilizer samples collected from fertilizer production enterprises. The measurement accuracy and detection limit of P by LIBS was improved under Ar atmosphere relative to air atmosphere. This study de-monstrated that the LIBS method can be used for analyzing the concentration of P in practical applications.
606-611 361
Abstract
A method for determining lead (Pb) and cadmium (Cd) in cosmetic products by an inductively coupled plasma atomic emission spectrometer (ICP-AES) is described. The acid digestion approach using concentrated HNO3, HNO3-HClO4, and aqua regia is performed, and the results show that the digestion of HNO3 is the most suitable procedure for cosmetics. The proposed method is then validated and optimized for Pb and Cd determination in terms of accuracy, repeatability, and day-to-day reproducibility. For diluted cosmetic samples, the limits of detection for Pb and Cd are 0.07 and 0.001 µg/g, respectively. This developed method is then successfully applied to the analysis of different facial cosmetic products, showing the contents of Pb and Cd within the ranges ~0.31-0.54 and ~0.01-0.24 mg/kg, respectively. The determination recoveries for Pb and Cd are within 89.7-104.4%, and the relative standard deviations are less than 3.0% (n = 5), showing the good applicability of this proposed method for Pb and Cd quantification in cosmetic samples.
612-619 239
Abstract
This article presents the design and synthesis of a new variant of the 4-amino-1,8-naphthalimide fluorescent probe for monitoring the divalent copper ion, Cu2+ . The probe BRST, functionalized with two propionic carboxylic acid groups in its receptor moiety, demonstrated high selectivity and sensitivity for the detection of Cu2+ in competitive media of various metal ions in DMSO/HEPES buffer solution (1:1; pH 7.4), with a fluorescence quenching of 75.41%. Besides its good linearity with Cu2+ , the probe yielded commendable values of the association constant and the detection limit, 5.54´105 M-1 and 4.33´10-9 M, respectively. The quenching of the fluorescence intensity of the sensor in the presence of Cu2+ ions is attributable to the strong paramagnetic nature of the Cu2+ ion. The fluorescence “turn off” behavior of this simple and effective probe was successfully applied for the determination of Cu2+ levels in untreated water samples, with excellent recovery rates of 98-105.8%.
620-626 231
Abstract
The filtration of optical signals and the transformation of information using stimulated echo-holography in the case when its excitation occurs with the use of an object laser pulse carrying information and a pulse that acts as a frequency filter are considered. It is shown that the temporal form of the signal of the stimulated echo-hologram depends on the duration, amplitude, and area and time structure of the exciting pulses.
627-633 220
Abstract
The present-day state of the metrological support of neutron spectrometry is herein considered. We propose a method of the formation of reference neutron fields with various forms of energy spectra from radioisotope sources for creating a test facility for verification of the developed real-time neutron spectrometers.
634-638 265
Abstract
Presented results of chromotographic and IR-spectroscopic researches of diesel fuel samples from Azerbaijan oils. Concentration, radiation-chemical yields of gases after irradiation of samples are established and estimated their radiation stability. Investigated impact of radiation on operational characteristics of diesel fuel in static conditions before and after irradiation.
639-644 252
Abstract
An IR-spectroscopic technique for determining the degree of nitration of b-cyclodextrin has been elaborated. It permits to determine the total number of ONO2-groups in partial b-cyclodextrin nitrates. The relative error of the measurement of the proposed method is 2%. The measurement range for the degree of nitration is from 33 to 100% of nitrate groups per the β-cyclodextrin molecule.
645-651 301
Abstract
The accuracy analysis of distance determination by range-intensity correlation methods in the case of arbitrary pulse shape is performed. It is shown that the absolute error is proportional to the pulse duration tL. For the trapezoidal shape of the pulse, which is a reasonable approximation of the real pulse shape, analytical estimates of the extreme error and range at which it is realized are obtained. For the model of trapezoidal pulses, maximum of the distance absolute error corresponds to extremely asymmetric pulses and is 10% of the spatial pulse length tLc, where c is the light velocity. At the same time, symmetrical pulses produce an error due to the pulse non-rectangularity approximately two times smaller. Since the trapezoidal shape is able to reproduce qualitatively the shape of almost any real pulse, it is very likely that the trapezoidal pulse model estimates the maximum possible error.
652-657 209
Abstract
This paper presents the results of the study of new photo-crosslinkable benzaldehyde polymers with fragments including long hydrocarbon substituents in the side chain as materials for creating a predetermined distribution of the director pretilt angle in the liquid crystal cell. It is shown that by changing the exposure dose of ultraviolet irradiation after rubbing the polymer layers, any pretilt angle can be obtained in the range 90-0°. The distribution of pretilt angles necessary for the creation of a liquid crystal lens was formed, and the values of the azimuthal anchoring energy of liquid crystals with the alignment layer were increased to 2.5 × 10- 5 J/m2, which made it possible to reduce the number of defects and to improve the optical quality of the liquid crystal lens substantially.
658-665 277
Abstract
The algorithm is developed for solving the inverse problem of multiangular spectrophotometry of a layer on a plane-parallel substrate of finite thickness using s and p waves. The algorithm allows investigating dispersion properties of the layer and substrate both in the vicinity and far from the resonant wavelengths. The dispersion properties of the layers of pure and aluminum-doped zinc oxide on a glass substrate are investigated. It is shown that the doping leads to a shift in the maximum of the absorption band to the short-wavelength region and to a decrease in the refractive index of the material. The applicability of known approximate expressions for determining the spectrum of the absorption index of a layer from spectrophotometric data is estimated.
666-672 271
Abstract
It is shown that the nonmetal element boron can change the melt structure and essentially influence the features of the structure and the physical characteristics of lithium niobate crystals. At the same time, boron does not embed in the crystalline structure. Meanwhile, the crystals grown from the charge doped by boron using the direct solid-phase method possess a higher photorefractive effect in comparison with the crystals obtained from the charge homogeneously doped by boron of the re-extract at the stage of niobium pentoxide extraction.
673-678 292
Abstract
Herein, the non-collinear acousto-optical two-stage diffraction of Bessel light beams by ultrasound in uniaxial gyrotropic crystals is theoretically and experimentally investigated. It is established that when Bessel light beams propagate along the optical axis of the crystal, the diffracted light beams of the ±1-th orders arrange symmetrically to the incident beam and have virtually the same intensity. When a Bessel light beam falls at the Bragg angle and near the optical axis, the two-stage Bragg diffraction is also observed, but the intensities of the diffracted beams of the +1-th and +2-th orders differ significantly from each other.

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679(1)-679(8) 226
Abstract
The 4s2-4s4p E1 transitions for Zn-like ions from Z in the range 30-92 are calculated using the multi-configuration Dirac-Hartree-Fock (MCDHF) method. The results obtained are in good agreement with other theoretical and experimental data and demonstrate the applicability of this method to high-precision atomic structure calculations of both few-electron systems and large atomic systems, such as Zn-like ions, along the entire isoelectronic sequence. We also report herein the calculations of many-electron quantum electrodynamic (QED) and Breit effects for the3P0,3P1, 3P2, and1P1 states for all Zn-like ions in the range 30 ≤ Z ≤ 100.
680(1)-680(6) 248
Abstract
This paper reports the first attempt at the synthesis of single phosphors of europium (Eu3+ ) and dysprosium (Dy3+ ) co-doped hydroxyapatite (HA)/b-tricalcium phosphate (TCP) nanostructures providing strong red and yellow luminescence depending on annealing temperature and holding time. The morphology of the phosphors was observed to have a nanowire structure. The photoluminescence (PL) intensity of the phosphors increases with annealing temperature and time. The luminescent phosphors also showed the typical luminescence of Eu3+ centered at 610 nm and Dy3+ centered at 572 nm, which was more efficient for the annealed Eu3+ /Dy3+ co-doped HA/TCP phosphors than for as-synthesized ones. These results suggest that the Eu3+ and Dy3+ co-doped HA/TCP nanostructures can find potential application in plant cultivation as environment friendly phosphors.
681(1)-681(6) 256
Abstract
Copper doped zinc sulfide nanoparticles have been synthesized using a wet chemical method. The synthesized nanoparticles exhibit a zinc blende structure with the crystallite size of 3.8 nm. The morphological and optical studies of the synthesized nanoparticles have been performed. It is found that the band gap varies from 3.6 to 4.4 eV depending upon the concentration of copper. The room temperature photoluminescence of the synthesized nanoparticles has been also investigated.
682(1)-682(10) 233
Abstract
Energy levels, transition rates, and lifetimes are reported for the low-lying 129 levels of Fe XIV, belonging to the n = 3 states (1s22s22p6)3s23p, 3s3p2, 3s23d, 3p3, 3s3p3d, 3p23d, 3s3d2, and 3p3d2. High-accuracy calculations have been performed as benchmarks in the request for accurate treatments of relativity, electron correlation and quantum electrodynamic (QED) effects in multi-valence-electron systems. The calculated energy levels are in excellent agreement with the experimental results and the experimentally compiled energy values, of the National Institute for Standards and Technology wherever available. The calculated values including core-valence correction are found to be in a good agreement with other theoretical and experimental values.
683(1)-683(11) 236
Abstract
A wavelength selection method for spectrophotometric analysis, named correlation coefficient optimization (CCO), was employed for reagent-free analysis of organics (humic acid) in real sewage. The modeling set of CCO uses the effluent in the ozonation process of humic acid (HA) solution. In order to verify the relationship between HA concentration and absorbance at the selected wavelength, HA solutions with different mass concentrations were prepared as a validation set. The study showed that the absorbance at 300 nm could be a good quantitative indication of HA concentration. In addition, the absorbance at 300 nm was applied to analyze the HA concentration in the ozonation process. The decomposition of HA fits the pseudo-first-order kinetic model and has a linear relationship with pH and (T - 20)2 (T is reaction temperature).
684(1)-684(10) 269
Abstract
Laser-induced fluorescence (LIF) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been applied for the non-destructive, label free, and rapid analyses of the impact of copper (25, 50, and 75 mM) on maize seedlings at an early stage before the changes appear visually on the plant. The LIF measurement has been used to detect the signs of stress in the photosynthetic pigment. The integrated areal intensity and increasing fluorescence intensity ratios indicate decrease in the photosynthetic pigments in the leaves of maize plants stressed with copper. The ATR-FTIR technique has been utilized to estimate the changes arising in the cell wall polysaccharides, amino acid, secondary structure of protein and lipid content of the leaves of control and copper-treated maize seedlings. The second derivative and curve fitting analysis have been applied for the enhancement of the spectral variations and quantitative estimation of the changes arising in the biochemical profile. The result shows an increase in the pectin, lignin, amino acid, and protein content and reduction in the amount of cellulose and lipid in the leaves of maize seedlings due to the treatment of copper. This study indicates the toxic response of copper by hampering the growth and reduction in the photosynthetic pigments and biochemical content of the maize seedlings. This study also demonstrates the feasibility of the spectroscopic techniques (LIF and ATR-FTIR) as a rapid, label free, and nondestructive probe for the assessment of stress and monitoring of crops.
686(1)-686(5) 214
Abstract
A double peaks bio-absorber, which includes two metal layers and one dielectric layer, is proposed. The surface metal layer of the bio-absorber is a square array that consists of a plum shape metal cell that can produce double resonance absorption. By studying the surface current and electric field z-component, the double peak is shown to originate from the two distinct resonance modes of the plum flower curves induced by the incident electromagnetic wave. Due to the symmetrical structure, the proposed bio-absorber is not sensitive to the polarization direction of incident waves and can maintain high absorption rates in a wide, range of angles.
687(1)-687(6) 257
Abstract
A 3D-printed microresonator based on a quartz tuning fork has been developed. The sensor performance is evaluated by detection of methane with a fiber-coupled distributed feedback diode laser. In combination with wavelength modulation spectroscopy, a minimum detectable concentration of 15.6 ppb by volume is achieved at atmospheric pressure with an 8-mW average optical excitation power and a lock-in amplifier time constant of 1 s, which corresponds to a 1σ normalized noise equivalent absorption coefficient of 5×10- 9 cm- 1 × W/Hz1/ 2 . An Allan variance analysis shows that the system has long-term stability and can serve as the basis for a portable gas analyzer. Approaches to improve the current sensor performance are also discussed. This design greatly reduces the time of manufacturing the microresonator.
688(1)-688(9) 221
Abstract
The interaction of the Eu(III)-BBR complex with herring sperm DNA is investigated using an acridine orange (AO) probe for UV-vis absorption spectroscopy and fluorescence spectroscopy. The results indicate that both the AO probe and the Eu(III)-BBR complex can intercalate into the base pairs of DNA. The binding constants of the Eu(III)-BBR complex with DNA are Kθ298.15K = 1.58 × 104 L/mol and Kθ308.15K = 9.35 × 104 L/mol, and the binding process is entropy-driven. It is shown that the interaction modes between the Eu(III)-BBR complex and DNA include groove binding and intercalative binding. The mechanism of the interaction between the Eu(III)-BBR complex and DNA will provide an important theoretical basis for the synthesis of new drugs.


ISSN 0514-7506 (Print)