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Novel 1,2,4-triazolium salts, 4-aryl-3-arylamino-1-(pyridin-2-yl)-1,2,4-triazolium bromides, were synthesized. These triazolium salts can be used as precursors of base-ionizable N-heterocyclic carbene (NHC) ligands capable of deprotonating the NH-acidic arylamino group. New Pd/NHC complexes, in which NHC acts as a bidentate C,N-donor chelating ligand, were prepared by metallation of the synthesized triazolium salts with palladium acetate. It was found that the obtained complexes have enhanced stability in strongly basic media and may be of interest as potential catalysts for cross-coupling reactions. [ABSTRACT FROM AUTHOR]

An approach was developed for the synthesis of novel 1,3-bis(4-R-2,6-dibenzhydrylphenyl)-4aminoimidazolium chlorides, precursors of amino-functionalized sterically bulky NHC ligands, starting from N-aryl formamides via reaction with POCl3 with subsequent amination of the in situ formed imidoyl chloride with arylamine and condensation of the thus formed formamidine with chloroacetonitrile. The applicability of the aminoimidazolium salts obtained for further functionalization of the NH2 group and selective metalation of the imidazole C2–H bond to give Cu/NHC and Pd/NHC complexes was demonstrated. [ABSTRACT FROM AUTHOR]

The metalation of 1,3-diaryl-4-(arylsulfanyl)imidazolium and 1,3-diaryl-4-(arylsulfonyl)imidazolium chlorides with copper(I) oxide has been studied. The resulting Cu/NHC complexes have been studied as catalysts for the carboxylation of phenylacetylene, benzoxazole, and benzothiazole. The main patterns of this reaction behavior and the dependence of the catalysis efficiency on the NHC structure were revealed. [ABSTRACT FROM AUTHOR]

The reaction of readily available N,N′-diaryl-4-chloromethylimidazolium chlorides with thiols afforded 4-(alkyl)arylsulfanylmethyl-N,N′-diarylimidazolium salts. The oxidation of these salts with hydrogen peroxide catalyzed by ammonium paramolybdate gave the previously unknown 4-(alkyl)arylsulfonylmethyl-N,N′-diarylimidazolium salts. The synthesized imidazolium salts can be used as sources of N-heterocyclic carbenes (NHCs). The conditions were found for the selective palladation of these compounds involving the C(2) atom of the imidazole ring. Palladium complexes with NHC ligands functionalized with RSCH2 and RSO2CH2 groups were synthesized. The potential applicability of these complexes as catalysts for cross-coupling reactions was demonstrated. [ABSTRACT FROM AUTHOR]

In this article, a method of depositing plasmonic particles on synthetic opal matrices was used for increasing the efficiency of laser-induced breakdown spectroscopy. The fundamental radiation, second and third harmonics of a picosecond neodymium laser were used to generate plasma. The dependences of the gain factor on the size of the laser spot, as well as on the concentration of silver particles, were obtained. The maximum signal amplification exceeding an order of magnitude was achieved at a wavelength of 1064 nm, corresponding to the localization of the plasmon resonance mode in the gap between closely spaced particles. Emission stability when using particles also increases at all laser wavelengths used. Conducted computer simulation confirmed the results of the experiment. High sensitivity of the method allows its use for monitoring even a small amount of impurity elements and their dynamics during the synthesis of photonic crystals, as well as the dynamics of the process of filling them with various materials during infiltration. [ABSTRACT FROM AUTHOR]

The cyclization of 5,6-diarylpyrrolo[3,4-d]pyrimidine-2,4-diones containing a halogen atom in the ortho-position of one of the aryl rings, proceeding as intramolecular C–H arylation catalyzed by Ru(II) complexes, was studied. It was found that complexes Ru(NHC)(cymene)Cl2, where NHC = IPr [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene], IMes [1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene], and their derivatives containing substituents at positions 4 and 5 of the imidazole ring, exhibit high catalytic activity. Based on the reaction studied, new representatives of pyrimido[5',4':3,4]pyrrolo[1,2-f]phenanthridine were obtained. [ABSTRACT FROM AUTHOR]

Options for using ordered 3D arrays of photonic crystals for the generation of gigahertz, optical, and neutron radiation upon interaction with a beam of high-energy electrons are considered. The optical emission spectra of photonic crystals produced in the interaction with a beam of relativistic electrons are presented. Experiments were carried out to obtain 2D images of objects in gamma and neutron fluxes generated in the interaction of an electron beam with a photonic crystal material. Various neutron generating targets are considered, for which the corresponding neutron yields were calculated. The characteristics of electromagnetic and neutron fields obtained in the experiment are also presented. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a novel approach to control the random lasing based on multiphoton luminiscence in Zinc oxide (ZnO) nanoparticle water suspension during its guided freezing process. The freezing process leads to the formation of a particle layer on the ice surface, consequently reducing the photon's scattering mean free path in the medium, as well as increase in the efficiency of the second harmonic generation. This results in a lowered random lasing threshold in the system. The post freezing threshold, under the 355 nm wavelength excitation, decreases by an order of magnitude. These effects may have several applications, including the phase transition sensing, monitoring the evolution of porous structures via the ice-templating technique, controlling the random lasing mode, and enhancing various nonlinear optical processes' effectiveness for nanoparticles and sub-micron particles in suspensions. [ABSTRACT FROM AUTHOR]

The main results of the long-term research on the synthesis and biological activity of phosphorylated imidates are presented, as well as the results of works that are a continuation of these studies and focused on phosphorylated mono- and diimidates obtained from malonodinitrile, a widely used reagent in the synthesis of pharmaceuticals, pesticides, and fungicides. [ABSTRACT FROM AUTHOR]

The isoperibolic calorimetry method was employed to determine, for the first time, the partial and integral mixing enthalpies for melts in the Eu–Ge system over the entire composition range at 1200 K and 1370–1440 K. The minimum mixing enthalpy for these melts was –49.1 ± 4.4 kJ/mol and was shown by the alloy with xGe = 0.45, while Δ H ¯ Eu ∞ = –145.7 ± 22.3 kJ/mol and Δ H ¯ Ge ∞ = –166.8 ± ± 19.8 kJ/mol at 1400 ± 3 K, correlating with the solid-state behavior of these melts. This allows categorizing these melts within the series of the Ge–Ln (lanthanide) systems and justifying the thermodynamic properties of melts in the Eu–Ge system, in particular, and in the Ge–Ln system, in general. Using the thermochemical properties for melts in the Eu–Ge system, the ideal associated solution model was employed to optimize and calculate the Gibbs energies, enthalpies, and entropies of formation for the melts, associates in melts, and intermetallics. A large number of associates, especially EuGe, formed in the studied melts because of the highest probability of collision between two dissimilar atoms in liquid alloys. The maximum mole fraction of the EuGe associate reached 0.48 and those of Eu3Ge, Eu2Ge, EuGe2, and EuGe3 were 0.2, 0.26, 0.24, and 0.26, respectively. The activities of components in melts of the Eu–Ge system showed substantial negative deviations from the ideal solution, correlating with our thermochemical properties. This all indicated strong interactions between dissimilar atoms in melts of the Eu–Ge system, likely involving the transfer of valence electrons of europium to the 4p orbital of germanium. The ΔG values over the entire composition range were greater than ΔH, with ΔGmin = –28.8 kJ/mol at xGe = 0.45. Moreover, the ΔG function was also almost symmetrical because of the entropy contribution (mixing entropy of the studied melts was negative, and ΔSmin = –15.0 J/mol K at xGe = 0.45). The calculations based on the ideal associated solution model also established that the Δ H ¯ Eu ∞ values for melts in the Eu–Ge system increased insignificantly with temperature, while Δ H ¯ Ge ∞ increased more substantially. This might be due to the break of covalent bonds between germanium atoms. Complete information on the thermodynamic properties of all phases was obtained, enabling a thermodynamic description of the Eu–Ge system for the first time. [ABSTRACT FROM AUTHOR]

The modern element base of electronics requires creating and obtaining new materials which are needed downsizing and improving the characteristics of the elements. Carbon nanotubes correspond to such conditions and have already found their application in nanoelectronics and other areas: supercapacitors, solar cells, gas and biosensors, and fillers of composite materials. Carbon nanostructures can contribute to the realization of a thermoelectric converter: their addition to the cathode composition causes a decrease in the emission temperature due to the functionalization of their conductive properties. This creates the prerequisites for the mass use of this energy conversion. [ABSTRACT FROM AUTHOR]

An anomalous (more than ten times) increase in the SRS intensity in liquids under picosecond excitation is detected as ultrasonic exposure on a medium is turned-on. The physical mechanism of the detected phenomenon is discussed. It is presumably associated with the formation of random feedback caused by the formation of inhomogeneities in liquid under ultrasonic excitation. [ABSTRACT FROM AUTHOR]

A new multicomponent reaction leading to the formation of an imidazole ring was discovered: N,N′-diaryl-1,4-diazabuta-1,3-dienes reacted with trialkyl orthoformates, chloro(trimethyl)silane and water to give N,N′-1,3-diaryl-4-oxoimidazolinium salts or their tautomers, 4-hydroxyimidazolium salts. [ABSTRACT FROM AUTHOR]

The reaction between N, N′-diaryl-4-chloromethylimidazolium chlorides and N-nucleophiles, viz. various azoles and azines, which proceeds via nucleophilic substitution of the chlorine atom in the chloromethyl group and leads to new dicationic 4-hetarylmethylimidazolium salts, was investigated. This reaction is reversible, whereas the yield of product of the nucleophilic substitution depends significantly on the structure of heterocyclic nucleophile and the nature of used solvent. A series of new dicationic 4-hetarylmethylimidazolium salts was obtained, and they are of interest as promising components of ionic liquids and precursors of N-heterocyclic carbenes. [ABSTRACT FROM AUTHOR]

An integrated experimental and thermodynamic modeling study has been used to characterize phase equilibria in the Pb-Fe-O-S-Si system. The experimental approach developed for investigation of this system, which involves the use of high-temperature equilibration, quenching, and electron probe X-ray microanalysis, has enabled to overcome difficulties associated with high corrosive tendency of the condensed phases and high vaporization rates of Pb species specific to this system. The study shows that systematic, accurate direct experimental measurements of the Pb, Fe, Si, and S concentrations in the coexisting phases in this system are now possible. The results obtained for the slag-matte-metal-tridymite phase equilibria at 1100 °C and 1200 °C appear to be the first systematic quantitative experimental data on phase compositions in equilibrium in the Pb-Fe-O-S-Si system. First systematic experimental measurements have also been undertaken for the gas-slag-matte-tridymite equilibria at p(SO2) = 0.6 atm at 1200 °C. Thermodynamic calculations have been performed using the FactSage thermodynamic package. The experimental data have been used, along with other relevant measurements, to develop a self-consistent thermodynamic database that can be used for optimization of industrial processes. [ABSTRACT FROM AUTHOR]

Laser-induced breakdown spectroscopy (LIBS) is first used to identify small impurity amounts in a three-dimensional ordered submicron dielectric structure exemplified by a synthetic opal matrix (SOM). A possibility of detecting metal-containing substances infiltrated in a SOM is demonstrated. The effect of the photonic bandgap and the excitation wavelength on the LIBS spectrum is shown. [ABSTRACT FROM AUTHOR]

The partial and integral mixing enthalpies of Cu-Yb melts were first determined at 1453 K in the composition range 0 < xCu <0.7 by isoperibolic calorimetry. The Cu–Yb melts were established to form with the release of a small amount of heat: minimum mixing enthalpy ∆H = –9.7 ± 0.8 (at xCu = 0.7), which agrees with the published data for these melts in the composition range 0 Yb < 0.3 at 1453 K and for other Cu–Ln systems. The model of ideal associated solutions was used to optimize and calculate all thermodynamic properties (Gibbs energies, enthalpies, and entropies of formation) for melts, intermetallic compounds, and associates in the Cu–Yb system. The calculated activities of components in the melts of this system exhibited moderate negative deviations from ideal solutions. The calculations with the ideal associated solution model also showed that Δ H ¯ Yb ∞ increased insignificantly and Δ H ¯ Cu ∞ more substantially in the Cu–Yb system with higher temperatures. The ideal associated solution model was applied to calculate temperature–composition dependences of the Gibbs energies, enthalpies, and entropies of formation for the melts and intermetallics to determine the coordinates of the liquidus curve in the studied phase diagram. The calculated and experimental data were in good agreement. Full information on the thermodynamic properties of all phases and phase equilibria in the Cu–Yb alloys was obtained. [ABSTRACT FROM AUTHOR]

A comparative study of the reactivity and transformation and degradation pathways under conditions of the oxidative acetoxylation was carried out for various palladium complexes. The implementation was confirmed for the NHC-connected mechanism of catalysis. Effects of the process of pyridine coligand elimination on catalysis were investigated. It was found that free pyridine inhibits the catalysis of oxidative acetoxylation of 2-phenylpyridine. Mono- and diacetoxyphenylpyridines were obtained regioselectively in 84–94% yields using Pd/NHC complexes of various structures. [ABSTRACT FROM AUTHOR]

The results of experimental studies of luminescence in ZnO powder under picosecond excitation are presented. It is shown that the luminescence spectrum excited by laser radiation with a wavelength of 1.06 μm contains a 531-nm line. Its intensity multiply increases as the sample is cooled to liquid-nitrogen temperature. The use of excitation with a wavelength of 532 nm gives rise to a line at 388 nm in the anti-Stokes spectral region. [ABSTRACT FROM AUTHOR]

In this paper, a solution of the mathematical model of an autowave process in a thin nearelectrode layer of a magnetic fluid is found. A modification of the FitzHugh–Nagumo system taken as the basis of the mathematical model made it possible to obtain results similar to a full-scale experiment. As a criterion for the adequacy of the model, we use a visual correspondence to the experiment and the presence in the solution of typical phenomena observed in the autowave process, such as reverbs, pacemakers, bypassing of obstacles, etc. [ABSTRACT FROM AUTHOR]

In this study, zero-phonon line (ZPL) at 638 nm associated with multiphoton excited negatively-charged single nitrogen-vacancy (NV)-center luminescence is registered in ethanol suspension of submicrometer diamond particles obtained at high pressures and high temperatures (HPHT). Simultaneously Stokes and anti-Stokes components of the stimulated Raman scattering (SRS) in the same sample is registered with a frequency shift of 1332 cm−1 corresponding to the fundamental optical mode of the diamond crystal. We observe anti-Stokes component intensity enhancement caused by its wavelength coincidence with the wavelength of luminescence caused by negatively-charged single nitrogen-vacancy (NV) centers. [ABSTRACT FROM AUTHOR]

Thermochemical properties of the In–Sr melt system are studied via calorimetry at 1070–1270 K in the full range of concentrations. Strongly negative thermal effects of mixing are typical of these melts. Activities of the components of the melt system, its Gibbs energies and entropies of mixing, and its phase diagram are calculated using the model of ideal associated solutions (IAS). Their values are found to agree with the literature data. [ABSTRACT FROM AUTHOR]

Depending on the active acidity of an aqueous solution, the colloidal stability of a titanium dioxide suspension in the form of anatase (food additive E171), containing nanoparticle with average sizes of ~10 and ~200 nm is studied. It is shown that the nanoparticle stability is reached in an alkali medium at pH > 9.6. A decrease in pH from 9.6 to 6.2 (neutral) results in an increase in the zeta-potential from –30 to –20 mV and is accompanied by the formation of nanoagglomerates ~20 nm in size involving small particles. In an acidic medium with pH ~2.6 (human stomach), the zeta-potential increases to +10 mV and is accompanied by small agglomerate coarsening to 50–60 nm. In this case, an increase in the average size to ~40 nm is observed even for ~2 min. The found rapid agglomeration should reduce the probability of E171 nanofraction penetration through cellular membranes in the human stomach. However, the Е171 nanofraction penetrability significantly increases in the small intestine where food intake mostly occurs, and a medium is close to neutral, pH ~ 8. [ABSTRACT FROM AUTHOR]

The calorimetry method was employed to determine the mixing enthalpies of Gd–Sn melts and the ideal associated solution (IAS) model to calculate and optimize the thermodynamic properties of Gd–Sn alloys at 1510, 1640, and 1873 K in the composition range 0 ≤ xSn ≤ 1.0. The minimum mixing enthalpies were –69.7 ± 0.6 kJ/mole (1873 K) and –77.9 ± 0.7 (1510 K) kJ/mole at xSn = = 0.45. Using our own and published data on the thermochemical properties of melts and compounds and assuming the formation of two associates in the melt, Gd2Sn and GdSn, we calculated the activities of components, enthalpies, Gibbs energies, and entropies of formation for the liquid alloys and intermediate phases within the IAS model. The thermodynamic activities of components in the studied melts showed very large negative deviations from the ideal solutions. The mixing enthalpies of Sn–Gd melts optimized within the IAS model agreed well with the experimental values. The Δ H ¯ Gd ∞ temperature dependence agrees only qualitatively with other experimental data because of great errors in the published data. The excess Gibbs energy and mixing enthalpy of Gd–Sn melts calculated with the IAS model at 1873 K greatly differed in magnitude, being indicative of a significant contribution of the entropy component to the excess molar Gibbs energy. According to the calculations, the minimum excess mixing entropy for Gd–Sn melts at 1873 K was –20.3 J/(mole · K) at xSn = 0.45. The calculated and optimized enthalpies and entropies of formation for intermetallic phases in the Gd–Sn system, along with the IAS model parameters for melts, were used to calculate the liquidus and solidus curves of the phase diagram. Good agreement with most experimental data on the phase equilibria involving liquid and crystalline phases was shown. [ABSTRACT FROM AUTHOR]

New nickel(ii) complexes of the general formula LNi(Cp)X (L is an N-heterocyclic carbene (NHC) ligand of the 1,2,4-triazole or imidazole series; Cp is the cyclopentadienyl anion; X = Cl, I) are reported. In these complexes, the NHC ligands (L) contain an alkylamino group at the 3 or 4 position of the heterocycle. The synthesized complexes and structurally similar complexes without an alkylamino group were tested for catalytic activity in the Suzuki—Miyaura reaction. The introduction of an alkylamino group into the NHC ligand leads to the enhancement of the catalytic activity of complexes with N,N′-diaryl-substituted NHC ligands of the imidazole series and a decrease in the activity of the complexes with N,N′-dialkyl-substituted NHC ligands of the 1,2,4-triazole series. [ABSTRACT FROM AUTHOR]

The enthalpies of mixing of Ni–Ln NiPr melts (0 < xNi < 0.6) are studied via isoperibol calorimetry at 1600 ± 1 K. The enthalpies of mixing for Ni–Pr melts are characterized by high exothermic values. The minimum enthalpy of mixing for the melts of the considered system is −35.3 ± 0.9 kJ/mol at xNi = 0.6. The activities of the components and the molar fractions of the most stable associates in melts of the Ni–Pr system are estimated using the model of ideal associated solutions (IAS). Literature data (enthalpies of formation of PrmNin compounds, phase diagram of the Ni–Pr system) and the obtained thermochemical data are both used. Five associates are selected for calculations. It is shown that the activities of the components in the melts of this system display large negative deviations from Raoult's law, and the PrNi2 associate predominates in them. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) micropowders widely used in modern food industry may contain particles in highly-toxic nanoform. Unlike micrometer-sized crystals, which cannot penetrate cell membranes, TiO2 nanofraction causes the liver function damage, intestinal inflammatory response, and oxidative metabolism imbalance. In this study, we demonstrate the possibility of utilizing Raman spectroscopy for fast detection of nanofractions against the background of anatase TiO2 micropowders. The results reveal that the presence of nanofractions leads to the appearance of several physically-grounded features in Raman spectra of TiO2 associated with the weakening of the selection rules for first-order scattering processes, the size-related frequency shift of Raman-active vibrations, and the enhanced contribution of Raman processes related to the surface states. In combination with standard microfiltration methods, these Raman markers provide a simple method for express control of highly-toxic nanofractions in TiO2 micropowders used in the food industry. [ABSTRACT FROM AUTHOR]

The development of new methods for generating pulsed electromagnetic microwave radiation is currently an actively developing area of research. Schemes for microwave radiation generation with optical pumping are of great interest. In this paper we propose and experimentally demonstrate principally new method for photonic generation of microwave electromagnetic radiation. This method is based on the use of radiation of charged submicron particles oscillating at their own acoustic frequency. Laser radiation of the optical range implements an effective buildup of acoustic vibrations of submicron particles forming the system under study, according to the Raman mechanism. [ABSTRACT FROM AUTHOR]

Enthalpies of mixing of liquid alloys are determined via isoperibol calorimetry for the Gd–Sn system throughout the range of concentrations at 1873, 1640, and 1510 K, and for the Gd–Sn–Ni system along the radial section with a constant ratio of atomic fractions of tin and nickel: xSn/xNi = 0.68/0.32 at 1873 ± 5 K up to xGd ∼ 0.25. It is found that the melts of the Gd–Sn system form with the release of a large amount of heat ( = −68.4 ± 0.4 kJ/mol at xSn = 0.45). The calculations are performed using the geometric and analytical Redlich–Kister–Muggianu models of ΔH for melts of the ternary Gd–Sn–Ni system from similar data for binary boundary subsystems at 1873 K. The results show the minimum enthalpy of mixing of these ternary melts was established for the Gd0.55Sn0.45 alloy. It is shown that the experimentally investigated enthalpies of mixing of the Gd–Sn–Ni melts and calculated data using the Redlich–Kister–Muggianu model with ternary interaction parameter L = 500 kJ/mol agree satisfactorily with one another. [ABSTRACT FROM AUTHOR]

We experimentally register stimulated low-frequency Raman scattering (SLFRS) in the suspension of brome mosaic virus (BMV) in phosphate buffer with very high conversion efficiency. We identify two components of the SLFRS spectrum as the breathing and quadrupole modes of BMV and determine damping characteristics and gain factors for these modes. We show that, using the core–shell model for BMV and taking into account the influence of the environment, the acoustic properties of individual components of such a composite nanosystem can be determined. Thus, we define the sound velocity in the RNA core of BMV, in view of spectral characteristics of SLFRS. [ABSTRACT FROM AUTHOR]

Phase equilibria in the ZnO-"CuO0.5"-SiO2 system have been investigated at 1403-1948 K (1130-1675 °C) for oxide liquid in equilibrium with Cu-Zn metal (> 99% Cu) and solid oxide phases: (a) tridymite or cristobalite SiO2; (b) willemite Zn2SiO4; (c) zincite ZnO; and (d) cuprite Cu2O. Two-liquid immiscibility range in the high-SiO2 slags has also been studied. High-temperature equilibration on primary phase (SiO2, Cu2O), inert metal (platinum-iridium wire), or ceramic (Al2O3 for high-Cu2O slags) substrates, followed by quenching and direct measurement of Zn, Cu, Si and possible impurities (Al, Pt, Ir) concentrations in the phases with the electron probe x-ray microanalysis (EPMA) has been used to accurately characterize the system in equilibrium with metal. All results are projected onto the ZnO-"CuO0.5"-SiO2 plane for presentation purposes. [ABSTRACT FROM AUTHOR]

Phase equilibria in the CaO-ZnO-Fe2O3 system have been investigated at 1483-1673 K (1210-1400 °C) for oxide liquid in equilibrium with air and solid oxide phases: (a) zincite (Zn,Fe,Ca)O1+x; (b) spinel (Zn,Fe,Ca)Fe2O4; (c) lime (Ca,Zn)O; (d) calcium ferrites dissolving zinc oxide: brownmillerite Ca2(Fe,Zn)2O5−x, and calcium diferrite (Ca,Zn)Fe4O7. High-temperature equilibration on inert metal (platinum) substrates, followed by quenching and direct measurement of the Ca, Zn and Fe concentrations in the phases with the electron probe x-ray microanalysis (EPMA) has been used to accurately characterize the system in equilibrium with air. All results are projected onto the CaO-ZnO-"FeO1.5" plane for presentation purposes. The present paper presents systematic characterization of liquidus over a wide range of compositions in this system in equilibrium with air. [ABSTRACT FROM AUTHOR]

Phase equilibria of the ternary CaO-ZnO-SiO2 system have been investigated at 1170 °C to 1691 °C for oxide liquid in equilibrium with air and solid oxide phases: tridymite or cristobalite SiO2 (up to two immiscible liquids), pseudowollastonite (CS) CaSiO3, rankinite (C3S2) Ca3Si2O7, dicalcium silicate (C2S) (Ca, Zn)2SiO4, tricalcium silicate (C3S) (Ca, Zn)3SiO5, lime (Ca, Zn)O, zincite (Zn, Ca)O, willemite Zn2SiO4 and hardystonite (melilite) Ca2ZnSi2O7, covering the ranges of concentrations not studied before. High-temperature equilibration on primary phase (silica) or inert metal (platinum) substrates followed by quenching and direct measurement of the Ca, Zn and Si concentrations in the phases with the electron probe X-ray microanalysis (EPMA) has been used to accurately characterize the system. Liquidus phase equilibrium data of the present authors for the CaO-ZnO-SiO2 system are essential to obtain a self-consistent set of parameters of thermodynamic models for all phases. [ABSTRACT FROM AUTHOR]

Under ruby-laser excitation, we register stimulated Raman scattering (SRS) in different liquids, which are active in Raman scattering (water, ethanol, acetone) and are infiltrated into pores of synthetic opal matrices. We show that the SRS conversion efficiency is essentially higher than that for corresponding bulk materials. We demonstrate the possibility to use such a method for the determination and spectral analysis of small amounts of substances. In the samples under study, we observe the fine structure of the first SRS component coinciding in frequency with the spectral shift of stimulated low-frequency Raman scattering of light in an opal matrix caused by the transmission of vibrations from silica globules forming the opal matrix. [ABSTRACT FROM AUTHOR]

Phase equilibria of the Pb-Cu-Si-O system have been investigated in the range 933-1938 K (660-1665 °C) for oxide liquid (slag) in equilibrium with solid Cu metal, liquid Pb-Cu alloy, or both solid and liquid metals, and solid oxide phases: (a) quartz, tridymite, cristobalite (SiO2); (b) cuprite (Cu2O); (c) lead silicates (PbSiO3, Pb2SiO4, Pb11Si3O17); (d) lead oxide (massicot, PbO); and (e) copper plumbite (Cu2PbO2). High-temperature equilibration on silica or copper substrates, followed by quenching and direct measurement of Pb, Cu and Si concentrations in the liquid and solid phases with the electron probe x-ray microanalysis (EPMA) has been used to accurately characterize the system in equilibrium with Cu or Pb-Cu metal. All results are projected onto the PbO-"CuO0.5"-SiO2 plane for presentation purposes. The present study is a continuation of the previous investigation of this system by the authors in a part of the silica and cuprite primary phase fields. Present data were later used to develop the thermodynamic models for all phases in this system. [ABSTRACT FROM AUTHOR]

We realize real-time image processing due to nonlinear Fourier-spectrum filtering by an emulsion of submicrometer particles of oil in water. We show that the emulsion of submicrometer particles of oil in water can be used as an effective amplitude–phase filter that nonlinearly changes the amplitude and phase of coherent radiation. [ABSTRACT FROM AUTHOR]

The thermochemical properties of Ni–Sb alloys at 1241, 1363, and 1457 K in the range 0 ≤ xNi ≤ 0.5 were studied by calorimetry. The ideal associated solution (IAS) model was employed to calculate the thermodynamic properties of Ni–Sb intermetallics and melts. The minimum mixing enthalpy is – 26.9 kJ/mole at xNi = 0.58 and agrees with the values for Sb–3d-metal alloys. Our and literature data were used to predict the formation enthalpies of melts and intermetallics in the binary Sb–3dtransition metal systems. [ABSTRACT FROM AUTHOR]

Abstract—This paper reports an analysis of a stochastic model of ion dynamics in the cardiac pacemaker cell within the framework of the generalized two-oscillator Maltsev–Lakatta model, including the electron-conformational model of ryanodine receptors. It has been demonstrated that generation of an action potential depends significantly on the nature of the interaction between the external membrane and the internal (Ca2+ clock) oscillators. Constructive interaction between oscillators leads to the formation of a stable action potential, while destructive interaction leads to parasitic effects, in particular, to arrhythmias. The effects of the model parameters that are characteristic of the rabbit sinoatrial heart node on the shape of the time dependence of the cell membrane potential has been investigated. The conditions under which spontaneous transition to the abnormally fast oscillatory mode takes place have been determined and the mechanism of this transition has been described; the pacemaker cell behavior in tachycardia has actually been simulated. It has been demonstrated that suppression of the rapid potassium current leads to the recovery of the normal oscillation mode of ion dynamics in a pacemaker cell, which corresponds to the mode of action of class III antiarrhythmic agents. [ABSTRACT FROM AUTHOR]

Phase equilibria of the Pb-Fe-Si-O system have been investigated at 958-1913 K (685-1640 °C) for oxide liquid in equilibrium with air and solid oxide phases: (a) quartz, tridymite or cristobalite SiO2; (b) hematite Fe2O3; (c) spinel Fe3O4+x; (d) complex lead-iron silicates (melanotekite PFS = PbO·FeO1.5·SiO2, barysilite P9−xFxS6 = (9 − x)PbO·xFeO1+y·6SiO2, "P5FS" = 5PbO·FeO1.5·SiO2, and "P6FS" = 6PbO·FeO1.5·SiO2); (e) lead silicates (alamosite PS = PbO·SiO2, P2S = 2PbO·SiO2, P11S3 = 11PbO·3SiO2, P5S = 5PbO·SiO2); (f) lead ferrites (magnetoplumbite PbO·12FeO1.5, plumboferrite PbO·(5 + x)FeO1.5, 1:1 lead ferrite PbO·(1 ± x)FeO1.5); and (g) lead oxide (PbO, massicot). High-temperature equilibration on primary phase or inert metal (platinum, gold) substrates, followed by quenching and direct measurement of Pb, Fe and Si concentrations in the phases with the electron probe x-ray microanalysis (EPMA) has been used to accurately characterize the system in equilibrium with air. All results are projected onto the PbO-"FeO1.5"-SiO2 plane for presentation purposes. The present study is the first systematic characterization of liquidus over a wide range of compositions in this system in equilibrium with air. [ABSTRACT FROM AUTHOR]

Phase equilibria of the Pb-Fe-Ca-O system have been investigated at 1043-1653 K (770-1380 °C) for oxide liquid in equilibrium with air and solid oxide phases: (a) hematite Fe2O3; (b) spinel (Fe,Ca)Fe2O4; (c) calcium ferrites CaFe4O7, CaFe2O4, Ca2Fe2O5; (d) lead ferrites (magnetoplumbite (Pb,Ca)O·12FeO1.5, plumboferrite (Pb,Ca)O·(5 + x)FeO1.5, 1:1 lead ferrite (Pb,Ca)O·(1 ± x)FeO1.5); (e) lead oxide PbO (massicot); (f) calcium plumbate Ca2PbO4; and (g) lime CaO. High-temperature equilibration on inert metal (platinum, gold) substrates, followed by quenching and direct measurement of Pb, Fe and Ca concentrations in the phases with the electron probe x-ray microanalysis (EPMA) has been used to accurately characterize the system in equilibrium with air. All results are projected onto the PbO-"FeO1.5"-CaO plane for presentation purposes. The present study is the first systematic characterization of liquidus over a wide range of compositions in this system in equilibrium with air. [ABSTRACT FROM AUTHOR]

It is shown by optical methods using light scattering intensity and shift of the stimulated low- frequency Raman scattering line that emulsion particles of the Emulson EM-1 lubricant-coolant are not monolithic drops but rather rigid aggregates of micelles. As the emulsion concentration decreases, the drops undergo a transition from the state of a monolithic droplet or a dense micellar aggregate to the state of a micellar aggregate with interlayers. The same also applies to water emulsions in transformer oil. [ABSTRACT FROM AUTHOR]

The results of experimental observation of stimulated low-frequency Raman scattering (SLFRS) in a single-crystal diamond with a buried graphitized layer created as a result of nonlinear interaction of high-power nanosecond laser pulse with eigen oscillations of nanosized layers of diamond-graphite structures are presented. It is demonstrated that the frequency shift of the SLFRS is on the order of 10 GHz and is inversely proportional to geometrical dimensions of the nanolayers composing the structure. [ABSTRACT FROM AUTHOR]

An effective one-pot method was developed for the preparation of organophosphorus derivatives of imidic acids based on the reaction of mono- and diimidates hydrochlorides with dialkyl chlorophosphates in the presence of triethylamine without isolation of free imidates. [ABSTRACT FROM AUTHOR]

Stimulated low-frequency Raman scattering (SLFRS) can provide important information on elastic properties of different nanoparticle systems, in particular, biological nanostructures. In the present study, for the first time we investigate low-frequency vibrational modes in human and bovine serum albumin (HSA and BSA), in view of the SLFRS method. We use 20 ns ruby-laser pulses for excitation. The SLFRS frequency shifts, corresponding to acoustic eigenfrequencies of the sample, are registered by Fabry–Pérot interferometers. For HAS, the set of eigenfrequencies obtained is 6 GHz (0.2 cm−1), 10 GHz (0.33 cm−1), and 15.6 GHz (0.52 cm−1), while for BSA, it is 8.7 GHz (0.29 cm−1) and 16.5 GHz (0.55 cm−1). We also measure the conversion efficiency and threshold. The SLFRS can be applied for biological-object identification and impact on the biological objects. [ABSTRACT FROM AUTHOR]

In this paper, a new method for the formation of complex therapeutic electron fields with taking the anatomical features of patients into account has been proposed. This method is based on the use of plastic electron beam collimators that are manufactured by rapid prototyping technique. The analysis of the plastic collimators application efficiency for the formation of an electron field using an ONCOR Impression Plus medical accelerator (Siemens) in a real clinical case has been carried out. The results prove the high efficiency of the proposed method for the formation of clinical electron beams. [ABSTRACT FROM AUTHOR]

Abstract: A primary response of the innate immune system to a pathogen invasion or tissue damage is the synthesis of tissue cytokines. Interleukins (IL) 25 and 33 or thymic stromal lymphopoietin (TSLP) are produced by epithelial or muscle cells in response to pathogen fragments, i.e., pathogen associated molecular patterns (PAMPs) or endogenous stress factors (danger associated molecular patterns, DAMPs). The goal of this work is to compare the ability of the bacterial peptide N-formyl-met-leu-phe (fMLP) and an endogenous pruritus inducer, amino acid β-alanine, to stimulate the expression of tissue cytokines. It has been shown by quantitative PCR that fMLP stimulates the ex vivo gene expression of TSLP and IL-25 in murine trachea explants, and β-alanine also stimulates IL-33 gene expression. The in vivo level of TSLP and IL-33 has been evaluated by ELISA in lung homogenates 1 and 6 h after intratracheal injection of the stimulants. Both β‑alanine and fMLP induce the release of IL-33 and TSLP from the intracellular depot. It is shown for the first time that β-alanine and fMLP are activators of tissue cytokine synthesis. [ABSTRACT FROM AUTHOR]

The reactions of С-phosphorylated malonodiimidates with acid chlorides in the presence of triethylamine were found to occur selectively under mild conditions and involve acylation of the imino group. The synthesized compounds are most likely to exhibit high antipsoriatic and other biological activities. [ABSTRACT FROM AUTHOR]

Representatives of the new heterocyclic system, pyrimido[5’,4’:3,4]pyrrolo[1,2-f]phenanthridine, were obtained via the intramolecular C-H-arylation of 6-aryl-5-(2-bromophenyl) pyrrolo[3,4-d]pyrimidine-2,4-diones catalyzed by palladium complexes with N-heterocyclic carbene ligands (Pd/NHC). [ABSTRACT FROM AUTHOR]

The transmission spectrum of a holographic sensor (silver nanograins embedded in a polymer matrix) is shown to be well described by expressions for the Rayleigh light scattering and absorption by silver nanograins. The optical characteristics of the medium are determined in the Maxwell Garnett approximation. In the presence of a holographic structure, a dip appears in the spectrum. A possibility of obtaining the approximating curves depends on the approximation range. The spectra are well approximated both in the presence and in the absence of an interference structure. For different approximation ranges, the dip parameters coincide despite the values of the background parameter associated with absorption can differ significantly. [ABSTRACT FROM AUTHOR]

Phase equilibria of the Pb-Cu-Si-O system have been investigated in the temperature range from 1073 K to 1673 K (800 °C to 1400 °C) for oxide liquid (slag) in equilibrium with solid Cu metal and/or liquid Pb-Cu alloy, and solid oxide phases: (a) quartz or tridymite (SiO2) and (b) cuprite (Cu2O). High-temperature equilibration on silica or copper substrates was performed, followed by quenching, and direct measurement of Pb, Cu, and Si concentrations in the liquid and solid phases using the electron probe X-ray microanalysis has been employed to accurately characterize the system in equilibrium with Cu or Pb-Cu metal. All results are projected onto the PbO-“CuO0.5”-SiO2 plane for presentation purposes. The present study is the first-ever systematic investigation of this system to describe the slag liquidus temperatures in the silica and cuprite primary phase fields. [ABSTRACT FROM AUTHOR]