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Hits: 10299
Are the data of physical and chemical studies of flasks given? chemical, phase and granulometric composition, degree of crystallinity, as well as their thermal stability in the temperature range of 90 - 1000 ° C. An increased reactivity of silica in the studied flasks, a low degree of crystallinity and a high degree of dispersion of flasks are shown, which contributes to the activation of structural and chemical transformations in flasks during their heating.
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Hits: 10345
The types and purpose of foam glass are considered, depending on the used blowing agents. Compositions with different granulometric composition of the charge have been developed, and heat treatment has been carried out. The influence of the fractional composition of the foam glass mixture on the density and volume of foam glass and foam glass materials has been studied.
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Hits: 10410
The results of the development of powdered nanoporous glass (NPS) with a controlled pore size for solid-phase synthesis of oligonucleotides with an increased product yield are presented. By varying the parameters of thermal and chemical treatment of sodium-borosilicate glasses, an NPG with a narrow pore size distribution was obtained. It was found that the functional loading of the material was 72 ?mol / g. It was shown that the use of the developed NPS in the synthesis of long-chain oligonucleotides more than 7 times increases the product yield in comparison with similar material on the market.
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Hits: 10328
Presented are the properties and graphical dependences of the properties of bismuth borate glasses in a wide range of compositions? molar content from 20 to 80 & # 37; Bi
2 O
3 . In multi-bismuth glasses, both boron ions and bismuth ions are in two coordination states: В
3+ and В
4+ , Bi
3+ and Bi
6+ . The [BiO
3 ] groups play the role of a conditional glass former, but are weakly manifested in the IR spectra
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Hits: 10587
Complex studies of glass formation and determination of glass properties in the material system of materials quartz sand - colemanite - soda have been carried out. The possibility of using a multicomponent raw material of colemanite in the production of borosilicate glasses and glassware of various compositions and purposes has been established, and an assessment has been made of the prospects and efficiency of its application.
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Hits: 11093
A technique has been developed for the engineering calculation of the thermal resistance of the wall layer of glass, which allows, by taking into account the physical nature of the heat transfer process in semitransparent media, to ensure accuracy and simplify the assessment of temperature conditions in the melting basin of glass furnaces
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Hits: 11325
The regions in the volume of lanthanum-oborogermanate glass, modified by a femtosecond laser beam, have been investigated by optical microscopy and confocal Raman spectroscopy. The data obtained show that, at the stages preceding the formation of the LaBGeO
5 microcrystal, germanium nanocrystals are precipitated in the local heating zone when exposed to a femtosecond beam in a certain range of laser pulse energy. The correlation between the conditions of laser irradiation, leading to the appearance of germanium nanocrystals and the conditions with a high probability of ensuring the crystallization of the phases of the low-temperature modification of lanthanum borate and stillwellite-like lanthanum borogermanate, suggest that germanium nanocrystals can serve as nuclei for heterogeneous crystallization of LaBO
3 and LaBGeO
5
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Hits: 11291
The sol-gel processes occurring during hydrolysis in the presence of a surfactant, diethylamine, have been studied. It has been shown that the rate of tetrabutoxytitanium hydrolysis at minimum water concentrations and in the presence of diethylamine is determined by the competition between the condensation processes of TiO
2 nanoparticles and the adsorption of diethylamine molecules on the surface of TiO
2 particles.
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Hits: 11563
Mathematical models of the dynamics of temperature fields during annealing of glassware of complex configuration are presented on the example of container glass of cylindrical-conical and prismatic-cylindrical shapes. Critical areas corresponding to the minorant and majorant of the thermal field were identified. The results of computer simulation of the dynamics of thermal fields of glassware are presented.
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Hits: 11546
The data of a comparative analysis of the melting and working properties of glass with the composition of E grade fiberglass with colemanite and calcium borate are presented. The physicochemical properties of the synthesized glasses based on colemanite and calcium borate have been investigated.
