摘要:

Aqueous solutions of Na2Zn‐EDTA began to decompose at 330°C under hydro‐thermal conditions, with rapid growth of ZnO crystals. Fairly smooth needlelike crystals of ZnO were obtained at Na2Zn‐EDTA concentrations of10 MPafor<

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19720.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A calcium phosphate glass‐ceramic crown for dentistry was developed. The glass is cast into the shape of the crown by the lost‐wax technique and subsequently heat‐treated to convert it into the glass‐ceramic, which exhibits excellent mechanical strength. The fine structure of the glass‐ceramic is similar to that of the enamel of a natural tooth, and its hardness is near that

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19707.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

To control ceramic drying and calcining operations, an approach that ensures uniform gas evolution was developed to prevent cracking on sudden release of gas. Instead of increasing temperature according to a preset schedule, the output signal from a thermogravimetric analysis apparatus is used as input to a computer system which varies temperature as required to cause mass loss to follow a preselected schedule. Materials that cracked when processed conventionally were prepared crack‐free by this procedur

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19708.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

During strength measurements on plastic‐coated optical glass fibers, the positions of fracture origins were determined by an acoustic technique. For samples other than those in which fracture was initiated at or very near the fixed ends, Weibull plots of the strength data exhibited a single‐mode distribution with low variability (m=20 to 25, corresponding to a coefficient of variation of 6.6 to 10.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19709.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

An electromotive force series for redox couples was defined as a function of oxygen fugacity in a borosilicate melt at 1150°C. The resulting order of relative reduction potentials can be used to estimate the amounts of redox species in glass during processing. The electromotive force series in this melt is comparable to those in other silicate glassforming melts and in aqueous systems but differs in detail because of interaction of the solvents with individual redox couples

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19710.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Reactive‐phase calsintering of calcium‐carbonate‐derived lime with Fe2O3additions was studied. Sintered densities>90% of theoretical were readily obtained. Densification trends and microscopic observations clearly identified the sintering process as one involving a liquid‐phase me

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19711.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The deviation from stoichiometry, δ, in Cr2−δO3was measured by a tensivolumetric method in the high pO2range of ≊104to 104Pa at 1100°C. The value of δ, or chromium vacancy concentration, was≊9×10−5mol/mol Cr2O3in air for Cr2O3with 99.999% purity. The chemical diffusion coefficient, DT, determined from equilibration data was ≊4.6× cm2·s−1at 1100°C for pO2= 2.2 ×101Pa. The self‐diffusion coefficient of Cr ions was calculated from and δ and found to be≊1.6×10‐17 cm2‐s−1, in good agreeme

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19712.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Monosized spheroidal doped TiO2particles with an average diameter of 0.3 to 0.7 μm were prepared by the controlled cohydrolysis of mixtures of titanium alkoxide and either niobium or tantalum alkoxide. An inorganic salt precipitation technique was used to put Ba, Cu, or Sr onto the surface of singly doped TiO2particles. Chemical analyses by several methods demonstrated the reproducibility and reliability of the doping procedure

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19713.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Clear glasses which included droplet‐like microphases were produced when SiO2in sodium borosilicate glasses was replaced by Sc2O3. Phase separation and/or crystallization occurred after heat treatment. The porous skeleton of leached glasses consisted of hexagonal ScBO3. The specific surface areas and pore radii are comparable to those of porous SiO2glass. The sintering temperature of porous Sc‐based material is higher than that of porous SiO2. Alumina contamination influenced the structure of the porous mater

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19714.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A nonlinear calibration curve for volume fraction vs integrated intensity ratio was obtained for the monoclinic‐tetragonal ZrO2system by using X‐ray powder pattern‐fitting and pattern‐decomposition techniques. The empirical equation agrees well with the theoretical one. By using this equation, the deviation from linearity (6.8% maximum) resulting from the intensity difference of corresponding reflections of the two phases can be estimated quite acc

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19715.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY