ISSN:0023-4753    

DOI:10.1002/crat.19790140818

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19790140819

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19790140820

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19790140821

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractSolution‐melts based on PbF2—B2O3and Bi2O3—B2O3were used in studying the stability regions and for growth, by way of spontaneous crystallization, of crystals up to 3 mm in size of twelve compounds having the general formula RGa3(BO3)4. All of these compounds are isostructural with carbonate mineral huntite. Their composition is highly dependent on that of the crystallization medium. The facing of the crystals is characterized by a small number of simple forms {1011}, {1120}, {2110}, and less frequently {0221}, {0112}, {4041}. The examined parameters include the IR spectra, luminescence spectra, heat of formation from oxides, harness (6 to 8 units on the Mohs scale) and o

ISSN:0023-4753    

DOI:10.1002/crat.19790140802

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractUsing of MSMPR technique for simultaneous obtaining crystal growth and nucleation data poses a problem in the case of size dependent growth systems. Namely, the necessary extrapolation of experimental population density plot down to zero size is dubious because of its very steep and varying slope. Thus only some effective nucleation rate can be determined accurately. The proposed method of calculating it comprises cutting population plot at some effective sizeLechosen as a fraction of dominant size of mass weighted CSD of product from MSMPR crystallizer. Such a point of reference enables to compare nucleation rates even of different systems. Correlations of experimental data for aluminium ammonium alum are presented.

ISSN:0023-4753    

DOI:10.1002/crat.19790140803

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractEs konnte gezeigt werden, daß Harnstoff beim Kristallisieren aus wäßrigen Lösungen mit NH4Cl Mischkristalle, Adsorptionsmischkristalle und epitaktische Aufwachsungen ausbildet. Das Ausmaß der Mischkristallbildung wird durch die Zusammensetzung der Ausgangslösungen bestimmt. Die Harnstoff/NH4Cl‐Mischkristalle wirken im Sinne von Morphologiewandlern auf Tracht und Habitus des auskristallisierenden Harnstoffs, wodurch anwendungstechnische Vorteile bezüglich Transport‐ und Lagereigenschaften r

ISSN:0023-4753    

DOI:10.1002/crat.19790140804

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractDendritic growth of potassium dihydrogen phosphate (KDP) crystals in silica gels at room temperature is reported. Branching along directions perpendicular to the arms and dendrites growing in mutually perpendicular 〈100〉 and 〈010〉 directions are illustrated. Initial stages and surface of a dendrite are illustrated and described. Also explained are the crystallites growing on the dendrite which finally lead to the formation of pl

ISSN:0023-4753    

DOI:10.1002/crat.19790140805

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe investigation of the element composition of TiCxlayers depending on depth profiles shows that the samples stored on air are coated by a contamination layer of hydrocarbons. The subjacent layer consists of about 19 mole‐% Ti, 26 mole‐% C, 45 mole‐% 0 and less than 5 mole‐% of Cr and Fe. The change of the position of the C1s, 01s and Ti2p‐lines depending on depth profiles allows us to draw conclusions from changes in the chemical bonding states of these elements. — A detailed profile analysis of the C1s‐line shows five different bonding states of carbon (CyHx, TiCx, Fe3C, elemental C and 〉CO‐compounds). The change of the O‐ and Ti‐bonding states within the layer consists particularly in decreasing OH‐bond as compared with oxide‐bond and also of Ti

ISSN:0023-4753    

DOI:10.1002/crat.19790140806

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe structural changes going on in an AlZn (15 at.%) alloy postaged between 125 °C and 215 °C after pre‐ageing between 20 °C and 90 °C (till startrs= (20…︁ 55) Å are obtained) were followed by means of XSAS‐investigations. The main results are the following:1An increase ofrsdoes not favour the growth of the precipitates during the reversion treatment.2At later reversion times the happening is obviously independent of the pre‐history of the samples.3The integral intensity is decreasing with increase ofTrev, but the mean distance (d)‐size (rG) relation between the precipitates is not changed remarkably up toTrev≈ 200 °C in the early reversion stage.Conclusions from thi

ISSN:0023-4753    

DOI:10.1002/crat.19790140807

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY