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We report on the fabrication of a hybrid light-emitting-diode based on colloidal semiconductor CdSe nanoplatelets as emitters and organic TAZ [3-(Biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole] and TPD [N, N′-bis (3-methylphenyl)-N, N′-bis (phenyl)-benzidine] materials as the electron and hole transporting layers. Electroluminescent and current–voltage characteristics of the developed hybrid device with the turn-on voltage of 5.5 V and the radiation wavelength of 515 nm have been obtained. Semiconductor nanoplatelets like CdSe are attractive for the fabrication of hybrid LEDs with low operating voltages, spectrally pure color and short-wavelength electroluminescence, which is required for RGB devices.

We report results of theoretical studies of dipole-bound anion formation reactions in collisions of polar molecules CH 3 NO 2 , CH 3 CN , and C 3 H 4 O 3 with Rydberg atoms Cs ( ns ) , Xe ( nf ) , and Rb ( nl ) ( l = 0, 3, and n − 1). It is shown that the inclusion of the long-range interaction effects into the calculations of the Rydberg-covalent–ionic coupling terms is crucial for a reliable quantitative description of such processes. A particular attention is paid to the comparison of the results obtained with the calculations performed using previous models and with the experiment.

The isotopic criteria used to predict the hydrocarbon phase composition were justified by a comparison of regional trends in the δ13C values for hydrocarbon liquids and gases from Riphean and Vendian–Cambrian deposits of the Lena–Tunguska petroleum province. The δ13C ratios for liquid hydrocarbons and gases, which are defined by kinetic isotope effects due to kerogen cracking during petroleum generation, were used as a criterion for establishing a genetic relationship between different hydrocarbon phases. The study has revealed that oil- versus gas-prone areas exhibit significant differences in the δ13C values and the reverse isotope distributions in the liquids and gases. In the oil-prone areas, methane becomes progressively enriched in 12C compared to oils and condensates, which is the normal trend of carbon isotopic compositions of liquid hydrocarbons and gases generated by organic matter of the same type and same maturity level. In the gas-prone areas, the δ13C values for methane either overlap with those of liquids or methane may show a general trend of enrichment in 13C relative to liquids. This relationship suggests that gases were probably generated and migrated later than oils, which may provide explanation for predominant gas accumulation in the study areas. The results of the isotopic studies and analysis of the geologic history of the region allowed the recognition of hydrocarbon kitchen areas that were potentially expelling late-stage gas to mostly gas-prone areas. The proposed isotopic method, i.e., a comparison of variations in carbon isotopic compositions of hydrocarbon liquids and gases, allowed us to establish a genetic relationship and discriminate between different hydrocarbon phases on the basis of the δ13C ratios. This can provide additional information about the timing of liquid hydrocarbons and gases generation and help to establish the likely locations of hydrocarbon kitchen areas and the history of hydrocarbon accumulations, thus improving the reliability of predictions for the hydrocarbon resource potential in the study areas and the phase composition of accumulated hydrocarbons.

The results of the experimental and theoretical studies of the optical absorption properties of the composite metal/organic nanoparticles in colloidal solutions are reported. The nanoparticles consist of Ag-core coated with the J-aggregate of 3,3′-disulfopropyl-5,5′-dichlorothiacyanine sodium salt (TC). The absorption spectrum of the composite Ag/TC nanoparticles exhibits two peaks at λ = 395 and 480 nm, which originally come from the localized surface plasmon resonance of Ag nanoparticles and the electronic excitation of TC-dye, respectively. To explain the results obtained we calculate the extinction cross-section of such composite material on the basis of a model for the polarizability of two concentric spheres by taking into account complex frequency-dependent dielectric functions of Ag and the TC-dye and size-dependent effects. The model provides a good description of the main features in the measured absorbance. It is shown that for the core–shell nanoparticles under investigation the peak positions and their intensities are strongly dependent on their geometrical size and the thickness of the J-aggregate coating. This opens a possibility to controllable driving of the absorption properties of such composite materials.

A pyrometer of IR radiation for monitoring the melting and strengthening temperatures of metals in vacuum systems is described. A diaphragmed optical system is used, which ensures the required spatial resolution and protects the pyrometer from the vaporizing metal. The measured temperature range is 20–1200°C, and the measurement accuracy is ≤ 2% at a time constant of 1 s.

Modern collision theory of Rydberg atoms with neutral and charged particles is presented. Recent results on the excitation, ionization, quenching and broadening of highly excited atomic states are reported. We consider in detail a number of approaches: various versions of perturbation theory, classical and semiclassical methods, Fermi pseudopotential model, impulse approximation and quasimolecular approach. Analytical and numerical methods developed within the framework of these different approaches presented in this review give both the simple qualitative description of elementary processes with Rydberg atoms and also reliable quantitative results. Both quasielastic transitions with small energy defect (l- and J-mixing processes) and the inelastic bound bound and bound free transitions with large energy transfer (n-changing processes, direct and associative ionization) are considered. In addition to the traditional mechanism of the perturber-quasifree electron scattering we analyze some efficient physical mechanisms due to the scattering of the perturbing atom or molecule on the atomic core of Rydberg atom. Considerable attention is paid to the comparison of theoretical results with available experimental data.

The annual production of solid domestic wastes by population of big cities of the USSR is about 37.5 million tons. The main method of disposal is burial in designated landfills. In the USSR large landfills occupy an area of more than 140,000 hectares. It has been calculated that the mass of the landfill deposits generating methane is today about 600 million tons. The studies carried out using geophysical, isotopic, and microbiological methods at different landfills of the Moscow region have shown that the emission of methane and other gases from the surface of landfills into the atmosphere is extremely irregular and considerably less than their generation in the anaerobic zone. The most important factors determining methane emission are the thickness of the layer of buried refuse, the heterogeneity of the deposit body, and the microbiological oxidation of gases in the upper aerated ground layer. It has been shown that the temperature in the anaerobic zone of big landfills is relatively constant and in most cases is 25–35°C. Methanogenesis often is most intensive in the upper part of anaerobic zone where the content of organic matter is rather high. The stable carbon isotope composition of the biogas generated from landfills is characteristic of the methanogenesis from organic wastes and depends on the concentration of organic matter and the age of the landfill. At first a lighter gas is generated and then a heavier one as the substrate is depleted. In the upper aerated ground layer of the landfill, about 1 meter in depth, methane, hydrogen, and carbon monoxide (CH4, H2, CO) are oxidized intensively. The number of bacteria oxidizing these gases reaches 1011 cells per gram of wet refuse. In this case the stable isotope composition of methane becomes heavier and, of carbon dioxide, lighter. It has been shown that at small landfills methane can be oxidized completely in aerobic zones. The gas-oxidizing ability of the microflora of the aerated ground layer of a landfill decrease considerably in the cold season of the year. The methane emission from landfills located in the USSR is estimated at 1.2 – 2.4 billion cubic meters per year. About two-thirds comes from the European part of the country. Effective methods of decreasing methane emission into the atmosphere are the extraction of biogas from big landfills and the maintenance of good aeration of the upper ground layer at the small ones.

This paper deals with (s,l)-cover-free families or superimposed (s,l)-codes. They generalize the concept of superimposed s-codes and have several applications for cryptography and group testing. We present a new asymptotic bound on the rate of optimal codes and develop some constructions.

Summary form only given, as follows. Radiometric methods of thermal inhomogeneities localization are very promising in medical diagnosis and treatment control (particularly, hyperthermia control). We have considered some cases of temperature inhomogeneities in the form of a finite depth layer /spl Delta/l with different temperature distribution from the surface (l=0) to depth. It has been shown on the basis of the radiation transport theory that the increment of the radiation effective temperature due to a temperature inhomogeneity depends on the temperature gradient T/sub 2/-T/sub 1/, depth of occurrence /spl Delta/l/sub 1/, inhomogeneity dimension /spl Delta/l/sub 2/ and tissue type. The dependence of increment /spl Delta/T-eff on the absorption coefficient (/spl alpha/) of a uniform tissue with a temperature inhomogeneity has a marked extremum. /spl Delta/T-eff maximum is shifted in the range of small parameters (/spl alpha/) with the increase of layer depth /spl Delta/l/sub 1/ and /spl Delta/l/sub 2/ (that corresponds to longer wavelengths). At a constant value of intermediate tissue /spl Delta/l the dependence of /spl Delta/T eff on the /spl alpha/ "hot" area dimension decreases with the increase of (/spl alpha/) (the wavelength decrease) and at some value of (/spl alpha/) it does not depend on the "hot" area depth. It has been noted that the approximation function of physical temperature T into tissue depth does not generally affect the type of T eff=f(/spl alpha/) except for the value of T-eff (step-function approximation, for example, T-eff decreases at all values of (/spl alpha/) as compared with the piecewise linear approximation). All these results have an obvious physical interpretation. The radiometer registers the radiation of intermediate tissues and a part of "hot" area radiation. At small wavelengths the main contribution in the brightness temperature is given by tissue subsurface layers. With the increase of the wavelength the radiometer grips other parts of the "hot" area and there is a growth of /spl Delta/T-eff. The maximum occurs at the wavelength where there is a minimum contribution from the "hot" area. At large values of (/spl alpha/) (long wavelengths) and small dimensions of the thermal inhomogeneity the increment of /spl Delta/T-eff tends to a constant value since the contribution from the second "cold" area will be dominant. Thus there is an optimal wavelength band from the viewpoint of the effective temperature increment maximum. This wavelength band is determined by the tissue type, inhomogeneity dimension and location.

A study has been made of the molecular characteristics of oligomers of molecular weight from 130 to 400 obtained by polymerization of ethylene oxide in 1,2-dichloroethane in the presence of boron trifluoride etherate and glycerol. In this range of MW the oligomers contain no side products distorting the number average functionality, apart from an insignificant admixture of diols due to the presence of water in reagents. It was found by gas-liquid chromatography that the molecular weight distribution is of the Poisson type. The results of periodate oxidation and the presence of secondary OH groups point to formation of branched molecules (as in anionic polymerization processes) whose fraction increases in the course of polymerization.

The results of the fractionation and the mol.wt. of polyoxypropylene polyols (POPP) produced by the polyaddition reaction of propylene oxide with potassium glycerate in glycerol have shown that the neutral polyether contains two diol types one of which is the product of water and propylene oxide, the other from hydrolysis of the cis -propylene groups in the mono-ol. The amount of the second diol type produced is equivalent to the cis -propylene groups content of the alkaline poly-ether. The OH-groups content of the neutral poly-ether equals the sum of the OH-groups present in the glycerol, water, allyl alcohol and from the cis -propenyl groups present in the alkaline polymer. This has qualitatively confirmed the mechanism of the chain transfer on the monomer during the anionic polymerization of the propylene oxide and has shown this reaction to be the only source of new OH-groups production during the polymerization.

(1973). Isotope composition of carbon in gaseous hydrocarbons and conditions for accumulations of natural gas. International Geology Review: Vol. 15, No. 3, pp. 300-308.

In previous communications [1, 2] it was shown that polyampholytes based on two unsaturated, stereo-isomeric acids (maleic and fumaric) and 2-methyl-5-vinylpyridine are substantially different in their behaviour in titration. This was associated with the different spatial configurations of the carboxyl groups in these copolymers. Another important feature of polyampholytes of this type, also associated with the use of an ethylene-1,2-dicarboxylic acid as one of the comonomers, is that the acidic component units in the copolymer will alternate with a definite number of units of the basic component. The purpose of the present work was to extend the study of the behaviour of these polyampholytes in potentiometric titration. In contrast to the earlier work attention here was directed mainly to study of the effect of change in the ratio of acidic and basic groups in the copolymers on their behaviour in titration.