摘要:

The liquidus surface for the high silica (>60 wt%) portion of the ternary system Na2O‐B2O3‐SiO2is presented. Determinations were made by quench runs and solubility studies. The compound, reedmergnerite, NaBSi3O8was not observed. Tridymite is the major primary ph

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15872.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

A solution‐gelation method for the preparation of polycrystalline zircon from zirconyl nitrate and tetraethoxysilane is described. Solution‐gelation methods are attractive because they can produce homogeneous starting materials and do not require any special equipm

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15873.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Measurements of the critical stress‐intensity factor, K10are reported for eight glasses of the chalcogenide system Se‐Ge‐As. The K10values are between 5.5 and 9.4 N.mm‐3/2. The dependence on glass composition can be understood qualitatively according to different short‐range order units of the Se‐Ge‐As glasses. A relation between fracture toughness, K10, microhardness, L2VH, and Young's modulus, E, may not be excluded for

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15874.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Reaction mechanisms occurring in the systems ZrO2‐Si3N4and TiO2‐Si3N4have been compared. The thermodynamics of several overall reaction mechanisms have been analyzed, including the effects of the gas phase composition to determine the most energetically favorable course of each react

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15875.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Ultrasonic velocity measurements conducted on Fe1‐xO single crystals grown along [100], [110], and [111] have led to the determination of the elastic constants C11C12, and C44. These constants are in good agreement with values previously calculated from neutron scattering data. There does not seem to be any influence of nonstoichiometry on these constant

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15876.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ZnO compacts were sintered in air from 450° to 700° C. By mercury porosimetry, pore size distributions, surface areas, densities, and porosities were determined. No shrinkage occurred below 550°C and, from a surface loss model, the mechanism was concluded to be surface diffusion. Activation energies are compared with those reported by other autho

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15877.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Electrical conductivity and thermoelectric power measurements on pure and Li‐substituted Co3O4were performed at 200° to 900°C. Impurity‐induced p‐type semiconduction was observed at low temperatures and intrinsic behavior at high temperatures. A hopping scheme for electron hole conduction was confirmed, and site exchange of cations in the spinel structure was proposed to explain the electrical conduction at high tempe

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15878.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Several soda‐lime‐silica glasses were melted in which up to 8.52 wt% zinc oxide was substituted for calcium and magnesium oxide. Sonic Young's modulus and Charpy impact resistance measurements were made. The results indicated that an increase of 8.52 wt % zinc oxide reduced the Young's modulus by 9.0% and increased the impact resistance of the soda‐lime‐silica glass

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15879.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The subliquidus miscibility gap in the system K2O‐B2O3‐SiO2has been determined for compositions with molar ratios SiO2/B2O3<2 and T≥550°C. The shape of the miscibility gap is an elongated dome similar in form to, but less extensive than those in the lithium and sodium borosilicate systems. The consolute composition (molar) and temperature are estimated to be 4 ± 1 K2O ‐30±8 B2O3‐66±8 SiO2and 629±5°

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15880.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Dissolution rate of silica glass in water was measured as a function of hydrostatic pressure at 285°C and was found to increase with increasing pressure. This observation appears to be contrary to the stress‐corrosion hypothesis of the static fatigue of gla

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb15881.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY