ISSN:0023-4753    

DOI:10.1002/crat.19730081214

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19730081215

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19730081216

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19730081217

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19730081218

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe magnetite skeletal crystals found in the copper production slags of the plant „Georgy Damianov”︁ in Bulgaria are investigated and described in the present work.The magnetite crystals were microscopically studied by means of reflected light on polished specimens, and as a result it was found out that every single skeleton represents a combination of an oktahedral skeletal multi‐edge form and a tetragontrioctahedral skeletal multiplane one.The morphology of the described form and its deviations from the ideal one are analysed in

ISSN:0023-4753    

DOI:10.1002/crat.19730081202

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe authors employed various physical and chemical methods for the purification of NaF. The efficiency of these methods was controlled by absorption measurements and chemical analysis. From purified material a single crystal was grown in every case, the absorption of which was measured by a vacuum ultraviolet spectrophotometer in the far UV wavelength range. The absorption at 142 nm was found to be indicative of the presence of several transition and heavy metal ions. The effect of doping with several alkaline and alkaline earth ions and furthermore with Cl−and OH−ions on these spectra is discussed. It is shown that certain chemical methods used for purification introduce Cl−ions into the material which are detectable by UV‐spectropho

ISSN:0023-4753    

DOI:10.1002/crat.19730081203

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe precipitation of barium, strontium, calcium, magnesium, zinc, cadmium, lead, cobalt, nickel and copper 8‐quinolinolates (‘oxinates’) was studied in buffer solutions (pHs from 10 to 4.5) at 22 °C: the metal cation and overall ‘oxinate’ with ‘oxine’ concentrations were varied from 0.0005 to 0.010 M (and saturation rations varied from 3 to 3.000). The induction periods, before the main growth surge, were measured at different metal oxinate concentrations (C MQ 2) and saturation ratiosS= (C MQ 2)/S·Pr1/3.Nucleation rates were determined from combined measurements of induction periods and final crystal numbers. Nucleation rates varied with saturation ratios according to the relation\documentclass{article}\pagestyle{empty}\begin{document}$ R_n = k_1 \cdot S^8 {\rm\ nuclei cm}^{ - {\rm 3}} {\rm sec}^{ - {\rm 1}} $\end{document}Induction periods decreased with increasing concentration and supersaturation; over the ranget>3.000 to<1 sec,\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{{\bar t = \bar t_{c_1 } } \mathord{\left/ {\vphantom {{\bar t = \bar t_{c_1 } } {C_{{\rm MQ}_{\rm 2} }^\alpha = {{\bar t_{S_1 } } \mathord{\left/ {\vphantom {{\bar t_{S_1 } } {S^\alpha }}} \right. \kern-\nulldelimiterspace} {S^\alpha }}}}} \right. \kern-\nulldelimiterspace} {C_{{\rm MQ}_{\rm 2} }^\alpha = {{\bar t_{S_1 } } \mathord{\left/ {\vphantom {{\bar t_{S_1 } } {S^\alpha }}} \right. \kern-\nulldelimiterspace} {S^\alpha }}}},} \hfill & {{\rm where}} \hfill & {\alpha = 3.0 \pm 0.2} \hfill \\ \end{array} $$\end{document}.Wheret c 1andt s 1were factors that depended on nucleation rates and metal salt solubility.t c 1values decreased andt c 1values increased with decreasing solubility. Precipitation occurred through homogeneous nucleation. Low nucleation rates and prolonged induction periods in solutions of medium to high supersaturation were related to slow rate‐determining stages in nucleus formation and to complex formati

ISSN:0023-4753    

DOI:10.1002/crat.19730081204

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe deformation of the (001) plane of LiF and NaCl by indentation and scratching at high temperatures was performed. The dislocation patterns arising from deformation were sharply different from those observed at room temperature. It was proposed the explanation of these results.The model of plastic flow in (001) indentation and scratching were considered. Anisotropy of hardness by the scratch method was revealed clearly at high temperatures. It was proposed the explanation of the anisotropy of hardness. The correlation was established between the dislocation structures observed near the indentations and scratches.

ISSN:0023-4753    

DOI:10.1002/crat.19730081205

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe application of various parameters for the estimation of the degree of homogenization of CuNi sinters is investigated. For this purpose specimens were prepared with different Ni contents, different degrees of initial porosity and different sintering periods. Analysis is done by means of point and line technique. The following parameters were used: standard deviation from the mean Ni content,\documentclass{article}\pagestyle{empty}\begin{document}$ S_c = \sqrt {\frac{1}{n}\sum\limits_{i = 1}^n {\left({c_i - \bar c} \right)^2 } } $\end{document}, variation coefficient\documentclass{article}\pagestyle{empty}\begin{document}$ v = \frac{{S_c }}{{\bar c}} $\end{document}, maximum concentration grapient of nickel,\documentclass{article}\pagestyle{empty}\begin{document}$ g = \left({\frac{{dc}}{{dx}}} \right)_{\max } $\end{document}and the relation of the minimum to the maximum Ni concentration in different points of the sinter. – These parameters are enough precise for the representation of the degree of homogenization, but besides this the latter enables to express the homogeneity in the form of a fraction as measure for the homogeneity of a sin

ISSN:0023-4753    

DOI:10.1002/crat.19730081206

出版商:WILEY‐VCH Verlag    

年代:1973

数据来源: WILEY