ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13112.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The infrared absorption spectra of sodium silicate glasses of molar composition Na2O·xSiO2(where = 5, 4, 3, and 2) were determined with unpolarized radiation in the 4 to 30μ region. The glass spectra showed a definite similarity to the spectra of α‐quartz, with lattice vibrational bands around 1066,786, and 464 cm−1. As x decreased, some bands shifted toward lower frequencies indicating a decrease in the force constant. No new frequencies were found in the silicate glasses which did not have counterparts in α

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13113.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Oriented hexagonal ferrite compounds of the formula BaO·[(2 ‐ × ‐ y)NiO·xCoO·yZnO] ·‐(7.8 —δ‐G)Fe2O3·δAl2O3are discussed for x = 0 to 0.8; y = 0 to 2.0; and δ= 0 to 1.0. Preparation procedures are described briefly. X‐ray techniques are used to determine the degree of orientation of the samples. Cobalt and aluminum substitutions result in a change of 4000 to 19,000 oersteds in anisotropy field for the range of substitutions made. Magnetization and anisotropy field data are reported for all substitutions. The temperature characteristics of the magnetization and the anisotropy field are reported for many of the compounds. The application of these materials in millimeter resonance isolators operating in the frequency region of 18 to 60 Gc

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13114.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The elastic modulus and transverse bend strength of pure, dense magnesia were determined as a function of grain size (1 to 190μ) and temperature (30° to 1500°C). The elastic modulus was essentially independent of grain size over the temperature range covered. The transverse bend strength for magnesia revealed a 1/6 power dependency versus grain size at low temperatures, i.e. STB= 50,000 G−1/6At temperatures above approximately 600°C, the strength of specimens of all grain sizes tested decreased with temperature and the grain size dependence, of strength also decreased. Nonlinear load‐deflection behavior was observed at temperatures above approximately 700°C and etch pit observations of dislocations produced during deformation and fracture of large‐grain magnesia specimens revealed extensive slip in grains adjacent to the fra

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13115.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The vapor pressure of plutonium dioxide (PuO2) was investigated in the range 1450° to 1775°C in air, argon, and oxygen atmospheres by a transpiration technique. There were strong indications that PuO2can vaporize congruently or as a suboxide species, depending on the atmosphere. The δH°298for vaporization in 1 atm of oxygen is approximately 154,000 cal per mole. The estimated standard free energy of formation (δG°f) of gaseous PuO2is −121,000 + 10.7Tfrom 1227° t

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13116.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The volatility of UO2±xand the phase relations in the system uranium‐oxygen were studied using thermogravimetric techniques. Chemical reactions describing the loss of uranium from UO2±xat temperatures between 1100° and 2200°C in oxygen pressures between approximately 102and 10−6torr are proposed. Results were obtained requiring the consideration of UO4(g) as the uranium‐bearing vapor species above UO2±x. Evidence supporting the existence of UO4(g) included the volatilization of material with an oxygen‐to‐uranium ratio of 4 during the decomposition of UO2+x(0.Z>×>0) to near‐stoichiometric UO2in vacuum above 1500°C and the dependence of the evaporation rate of the uranium dioxide on the oxygen pressure between 1200° and 1500°C. The equilibrium oxygen pressures over compositions between UO2.02and UO2.63in the UO2+xand U3O8‐yregions and over the boundary between these phases were measured between 1000° and 1600°C. The equilibrium oxygen‐to‐uranium ratio of UO2±xwas less

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13117.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13118_47_12.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

A method was developed for hot‐pressing 80 to 95% dense, polycrystalline specimens of commercially available, unstabilized, monoclinic zirconia. The elastic moduli of these specimens were measured by a sonic method in the range 25° to 1000°C. Application of mathematical expressions developed for the porosity dependence of elastic moduli of refractory oxides led to the calculation of Young's and shear moduli of this material at zero porosity in this temperature ra

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13120.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13121.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The activity of zirconium in the tetragonal ZrO2phase was measured at 2200° to 2300°K as a function of composition by studying the reactionFrom the variation of the zirconium activity with composition, the pairwise interaction energy E11between vacancies in the oxygen lattice was evaluated at ‐4.6 ± 1.0 kcal per

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb13122.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY