共查询到20条相似文献,搜索用时 15 毫秒
1.
The linear thermal expansion coefficients below and above the glass transition range and the glass transition temperatures in the SrO-B2O3-SiO2 system are determined using a quartz dilatometer. 相似文献
2.
S. V. Stolyar N. G. Tyurnina Z. G. Tyurnina L. A. Doronina 《Glass Physics and Chemistry》2008,34(4):509-511
The temperature dependences of the viscosity are investigated for three series of glass melts in the SrO-B2O3-SiO2 system with a constant strontium oxide content equal to 35, 40, or 45 mol % in the viscosity range from 1010 to 1013 P. 相似文献
3.
The density d at a temperature of 25°C is measured by the hydrostatic weighing method, the Vickers microhardness H V is determined, and the fluctuation free volume fraction f g is calculated for glasses in the SrO-B2O3-SiO2 system with a constant strontium oxide content in the range from 35 to 45 mol %. It is demonstrated that the quantities H V and f g decrease and the density d increases with an increase in the SrO content. 相似文献
4.
V. V. Golubkov N. G. Tyurnina Z. G. Tyurnina V. L. Stolyarova 《Glass Physics and Chemistry》2009,35(5):455-462
The structure of single-phase glasses in the SrO-B2O3-SiO2 system has been studied by the small-and large-angle X-ray scattering technique. The glasses containing 35, 40, and 45 mol
% SrO upon equimolar replacement of B2O3 by SiO2 have been investigated. It has been demonstrated that the glasses do not contain chemical inhomogeneity regions. The inhomogeneity
of the glasses is determined only by thermal density fluctuations. The isothermal compressibility varies insignificantly upon
replacement of B2O3 by SiO2 and decreases with an increase in the SrO content. The glass structure is consistent with the model of ideal associated solutions. 相似文献
5.
6.
The crystallization of strontium borate glasses containing 16.7–43.0 mol % SrO is investigated. New crystalline compounds of the hypothetical compositions 2SrO · 3B2O3 (metastable) and SrO · 5B2O3 (stable below 750°C), as well as the metastable diborate modification β-SrO · 2B2O3, are revealed, and their X-ray powder diffraction data are obtained. It is demonstrated that, with a deficit of strontium oxide, the 4SrO · 7B2O3 compound forms solid solutions. Strontium triborate SrO · 3B2O3, which was previously prepared only through the dehydration of crystal hydrates, is produced using crystallization of glasses. The thermal stability of this compound is studied. The influence of the dispersity on the stability of different crystalline phases is discussed. Variants of the phase diagram for the SrO · B2O3-B2O3 system in the case of monolithic and dispersed samples are proposed from analyzing the experimental results and the data available in the literature. 相似文献
7.
8.
V. V. Golubkov V. L. Stolyarova Z. G. Tyurnina N. G. Tyurnina 《Glass Physics and Chemistry》2010,36(5):554-560
The structure of single-phase glasses in the BaO-B2O3-SiO2 system has been studied by the large- and small-angle X-ray scattering techniques. The glasses containing 40 mol % BaO upon equimolar replacement of B2O3 by SiO2 have been investigated. It has been demonstrated that the incorporation of barium ions into structural groupings fixes their position and provides ordering in the distribution of barium ions at interatomic distances up to at least 5 Å. The glasses under investigation are homogeneous, and their inhomogeneity is determined by thermal density fluctuations and fluctuations of the concentration of a part of barium ions distributed in a statistically random manner in the volume of the glass. The observed ordering in the distribution of barium ions is not reduced to the formation of local clusters with an increased concentration of barium ions but is most likely a characteristic feature of the bulk glass structure. The glass structure is consistent with the model of ideal associated solutions. 相似文献
9.
10.
S. A. Nemov A. V. Marchenko P. P. Seregin E. A. Tomil’tsev 《Glass Physics and Chemistry》2007,33(6):658-660
Triply and doubly charged states of europium are revealed by 151Eu Mössbauer spectroscopy in the structure of glasses of the composition (mol %) 19.5Al2O3, 31.5SiO2, 26.5MnO, and 22.5Eu2O3. The isomer shifts in the Mössbauer spectra of Eu3+ and Eu2+ ions in the structure of glasses differ from the isomer shifts in the spectra of the Eu2O3 and EuO compounds. This difference is explained by the fact that the electron density at 151Eu nuclei is affected by the manganese and aluminum atoms, which are not bound directly to the europium atoms. The broadening of the spectra of the Eu2+ ions in glasses is caused by the nonuniform isomer shift. 相似文献
11.
Z. Kovziridze D. Aneli N. Nizharadze G. Tabatadze D. Gventsadze 《Glass Physics and Chemistry》2007,33(3):262-265
This paper reports on the results of investigations aimed at synthesizing ceramic materials with a high mechanical strength, as well as with high thermal and chemical resistances to corrosive media. The methods used for one-stage preparation of barite-based ceramic and polymer composites with these properties are considered. 相似文献
12.
G. V. Samoilenko Mohammad Arif E. V. Novikov L. A. Filatov L. N. Blinov 《Glass Physics and Chemistry》2004,30(6):515-518
Glasses in the Sb2S3-PbI2 system are synthesized, and their physicochemical properties are investigated. The glasses possess high refractive indices (up to 3 or greater). The phase diagram of the Sb2S3-PbI2 system is constructed from the data of differential thermal and X-ray powder diffraction analyses. The diagram exhibits an eutectic behavior. The eutectic is located at a content of 47 mol % PbI2 and at a temperature of 370 ± 5°C.Original Russian Text Copyright © 2004 by Fizika i Khimiya Stekla, Samoilenko, Mohammad Arif, Novikov, Filatov, Blinov. 相似文献
13.
Synthetic spinels of the system MgO-Cr2O3-Al2O3-Fe2O3 are considered and the desirability of organizing their production for the refractory industry is demonstrated.
Translated from Novye Ogneupory, No. 6, pp. 32–35, June 2008. 相似文献
14.
It is difficult to research on the surface structure of amorphous phase in fly ash during leaching reaction due to crystalline phase and complex structure. In the present work, in order to reveal the effects of leaching reaction on the surface structure of amorphous phase in fly ash, the modelling CaO-Fe2O3-Al2O3-SiO2 glass was prepared by the traditional melting methods. The leaching reaction of CaO-Fe2O3-Al2O3-SiO2 glass with 7.5 M KOH was investigated by spectroscopy, spectrophotometer and wet chemical method. The results show that the content of Q 1, Q 2, Q 3 and Q 4 of glass without corrosion was 4.21, 9.51, 23.03 and 52.55%, respectively, which shows that the network polymerization of glass is compact. The leaching reaction of glass can be described by the following equation: dS/dt = k/(r + S 0). Leaching in KOH for various times induces the content of Q 4 and Q 1 to be decreased, and Q 2 and Q 3 increased, resulted in the depolymerization of network and the surface glass dissolved in alkaline solution to form a gel phase. In stage one of leaching reaction, the rate of iron ion leached from glass surface was slow, which resulted in the small slope of straight-line relationship of leaching curve. In the following stage, the leaching rate of iron ion increased with the prolongation of time. 相似文献
15.
R. G. Kuryaeva 《Glass Physics and Chemistry》2008,34(1):37-41
The pressure dependences of the refractive index for aluminosilicate glasses of the compositions 0.167CaO · 0.167Al2O3 · 0.666SiO2 and 0.157CaO · 0.177Al2O3 · 0.666SiO2 at pressures up to 6.0 GPa are determined using a polarizing interference microscope and an apparatus with diamond anvils. The compressibilities of the glasses are calculated from the measured refractive indices within the framework of the theory of photoelasticity. The structural-chemical parameters NBO/T (where NBO is the number of gram-ions of nonbridging oxygen atoms and T is the total number of gram-ions of network formers) are calculated for the glasses under investigation with allowance made for the formation of triclusters and highly coordinated aluminum. 相似文献
16.
V. F. Popova E. A. Tugova A. S. Isaeva I. A. Zvereva V. V. Gusarov 《Glass Physics and Chemistry》2007,33(5):498-501
The phase formation is investigated and the phase diagram of the Ho2O3-SrAl2O4 system is constructed. A ternary compound, namely, Ho2SrAl2O7, is revealed. It is established that this compound undergoes incongruent melting. 相似文献
17.
V. A. Sokolov T. Ya. Malysheva M. D. Gasparyan 《Refractories and Industrial Ceramics》2008,49(2):146-148
Details are given of the synthesis and testing of flux-cast refractory materials in the alumina-rich region of the Al2O3-MgO-B2O3 system; XRD and petrography indicate that the main structure-forming phases are corundum and magnesian spinel. In subordinate
amounts there are the boroaluminate 9Al2O3·2B2O3 and the previously unknown compound 4Al2O3·MgO·2B2O3, whose composition has been established by microprobe analysis. Corrosion tests showed that three-component systems containing
magnesium and boron oxides at levels of 5–10% do not increase the corrosion resistance of refractories in molten sodium-calcium-silicate
glass and electrovacuum borosilicate glass.
__________
Translated from Novye Ogneupory, No. 3, pp. 161–163, March, 2008. 相似文献
18.
Yu. B. Petrov Yu. P. Udalov J. Subrt S. Bakardjieva P. Sazavsky M. Kiselova P. Selucky P. Bezdicka C. Jorneau P. Piluso 《Glass Physics and Chemistry》2009,35(2):199-204
The behavior of melts in the uranium oxide-silicon dioxide system is experimentally investigated in air upon induction melting in a “cold crucible.” The existence of the two-phase liquid region in this system is confirmed. It is demonstrated that the melts absorb oxygen from air, which leads to crystallization of the UO2.25 compound upon cooling. In the case of considerable internal heat release, sharp cooling of the melt surface results in the liberation of gas, which brings about bulging and, sometimes, melt ejection from the crucible. 相似文献
19.
O. V. Belyaeva T. A. Krasnova S. A. Semenova O. S. Gladkova 《Solid Fuel Chemistry》2011,45(6):418-421
The results of the modification of AG-OV-1 activated carbon under various conditions (by atmospheric oxygen at elevated temperatures
and by hydrogen peroxide or ozone) are given. The effect of the used modifier on changes in the porosity, surface state, and
adsorption capacity of activated carbon is evaluated. 相似文献
20.
V. N. Sigaev E. A. Alieva S. V. Lotarev N. M. Lepekhin Yu. S. Priseko A. V. Rasstanaev 《Glass Physics and Chemistry》2009,35(1):13-20
A method is proposed for local crystallization of glasses under laser irradiation. This method makes it possible to nucleate and grow microcrystals with a size distribution similar to a monodisperse distribution for several fractions of a second in any glass region chosen in advance. It is demonstrated using glasses in the La2O3-B2O3-GeO2 system as an example that the crystallization of the stillwellite-like phase LaBGeO5 with the composition close to the composition of the initial glass is observed in the glass under irradiation with the copper vapor laser operating in the high-speed pulse modulation mode. Strips (up to ~300 μm) produced at a specified depth from the glass surface contain extended regions consisting of uniformly distributed crystals, which have almost identical sizes, exhibit a pronounced faceting, and are identified using X-ray diffraction. The size and the number of crystals can be changed over a wide range by varying laser treatment conditions. This opens up the way to the design of new glass-ceramic materials in which the location of the crystalline phase in the glass bulk is controlled by a developer. 相似文献