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  • Chemistry  (82)
  • Barium sulfate suspensions  (1)
  • Bi garnets  (1)
  • Magnetism
  • 1970-1974  (84)
  • 1
    ISSN: 1432-0630
    Keywords: Magneto-optics ; Bi garnets ; Liquid phase epitaxy ; Crystal growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Single crystal thin films of Bi substituted iron garnets have been grown by the liquid phase epitaxy technique. The growth conditions and compositions are presented together with the segregation coefficients of Bi and Pb as a function of growth temperature. The Faraday rotation and optical absorption have been measured for wavelengths between 0.7 and 0.46 μm. The superior magneto-optic properties (Faraday rotations of up to ten times larger than that observed for Y3Fe5O12) make these epitaxial layers attractive for magneto-optic devices. The influence of Pb incorporation on the optical properties of the films is discussed. Compositions of Bi and Ga(Al) substituted Gd3Fe5O12, which exhibit a magnetic compensation temperature near room temperature and high Faraday rotation, have also been prepared. The magnetic switching behaviour as a function of temperature has been determined. It shows that these films are especially suited for thermomagnetic recording using an argon ion laser at a wavelength of 5145 Å.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 4 (1971), S. 38-45 
    ISSN: 1432-1041
    Keywords: Barium sulfate suspensions ; gastrointestinal x-ray examinations ; clinical trial ; controlled ; viscosity effects ; osmolarity effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The quality of radiographs of the upper gastrointestinal tract is of great diagnostic importance, but the published reports about barium sulfate suspensions have been poorly controlled or limited to in vitro investigations. The present study consists of a double blind clinical trial comparing two commercially available barium sulfate suspensions, several additives and methods used to alter the viscosity of the suspension. The techniques employed include randomization, factorial design, application of predetermined criteria and computer analysis of the results. The results confirm the value of high viscosity suspensions for examining the oesophagus, but for the stomach and the intestines a lower viscosity appears adequate. Elevation of osmolarity accelerates intestinal transit but impairs double contrast and mucosal pictures. Some highly significant differences between the two barium preparations, e.g. in gastric peristalsis, cannot be accounted for. The analysis of results shows that improvement of present day techniques is desirable, but will depend on further results of properly controlled clinical trials.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 2 (1971), S. 127-135 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Thermal aging and endurance of organic insulating materials. The knowledge of the thermal endurance of organic insulating materials is very important for the application in electrical engineering. The change of the values of the properties by thermal aging is, theoretically, described under the assumption being a linear connection to the rules of the kinetic theory of chemical reactions. By this premise it is possible to indicate functions for aging and thermal endurance, being plotted as straight lines in suitable coordinates. In this way the test results can be evaluated better than by conventional means.
    Notes: Die Kenntnis der Grenztemperatur organischer Isolierstoffe ist für deren Anwendung in der Elektrotechnik von großer Wichtigkeit. Die Änderung von Eigenschaftswerten auf Grund einer Wärmebehandlung wird theoretisch beschrieben unter der Annahme, daß ein linearer Zusammenhang mit den Gesetzen der Reaktionskinetik besteht. Unter den getroffenen Voraussetzungen können. Alterungs- und Lebensdauerfunktionen angegeben werden, die sich bei geeigenten Koordinaten als Geradendarstellen lassen. Meßergebnisse können auf diese Weise besser ausgewertet werden als nach herkömmlichen Verfahren.
    Additional Material: 9 Ill.
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  • 4
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Gold Flashing on Relay Contacts. It is not the colour but the resistance of contacts which determines their efficiency. Since, however, it is an expensive and time-wasting procedure to measure the resistance of every contact, many costomers reject relays whose silver contacts show a brownish-black discolouration, complaining that they have been kept too long in stock.This problem was believed to have been solved by the introduction of gold-flashing as a temporary coating while the contacts are kept in stock. Now the German Post Office's Telecommunications Head Quarters (Fernmeldetechnisches Zentralamt der Deutschen Bundespost) in Darmstadt have found indications which raise some suspecions as to the damaging side-effects of gold-flashing. For this reason, a working committee of the VDE (Association of German Electrical Engineers), group 1.6„Contact behaviour and switching processes“, undertook its own investigations. The results were revealed during a platform-discussion on the 3rd October, 1973 in the Technical College at Karlsruhe and are given here in the form of edited speeches and a summary of the discussion.
    Notes: Nicht die Farbe, sondern der Kontaktwiderstand ist ein eindeutiges Maß für die Brauchbarkeit von Kontakten. Da aber die Messung des Kontaktwiderstandes zeitraubend und teuer ist, weisen viele Kunden Relais mit braun-schwarz angelaufenen Silberkontakten als „überlagert“ zurück. Seit der Einführung der Hauchvergoldung als vorübergehender Lagerschutz galt dieses Problem als gelöst. Hinweise des Fernmeldetechnischen Zentralamtes der Deutschen Bundespost in Darmstadt haben Zweifel an der Unschädlichkeit der Hauchvergoldung aufkommen lassen und einen Arbeitskreis der VDE-Fachgruppe 1.6„Kontaktverhalten und Schalten“ zu eigenen Untersuchungen veranlaßt. Die Ergebnisse wurden in einer Podiumsdiskussion am 3. 10. 1973 an der Technischen Hochschule Karlsruhe vorgetragen und werden heir als Kurzfassung der Vorträge und Zusammenfassung der Diskussion wiedergegeben.
    Additional Material: 4 Ill.
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  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Phosphorus. 53. 1,2,3,4-Tetraphenylcyclo-5-thia-1,2,3,4-tetraphosphane1,2,3,4-Tetraphenyl-cyclo-5-thia-1,2,3,4-tetraphosphane (“tetraphenylcyclotetraphosphine-monosulphide„) 1 is obtained in very good yield and purity by the reaction of pentaphenyl-cyclopentaphosphane (2) with sulphur (4 C6H5P: 1 S). Further new methods of preparation are the comproportionation of 2 with (C6H5PS)3, and the reaction of dipotassium-triphenyl-cyclotriphosphide (4) with sulphur dichloride. The IR and 31P-NMR spectra of the title compound indicate unambiguously the heterocyclophosphane structure 1 with a five-membered P4S ring. The elevated stability of this ring system is evident from numerous other formation reactions, which are reported in addition.
    Notes: 1,2,3,4-Tetraphenyl-cyclo-5-thia-1,2,3,4-tetraphoshan (“Tetraphenyl-cyclotetraphosphin-monosulfid”) 1 wird durch Umsetzung von Pentaphenyl-cyclopentaphosphan (2) mit Schwefel (4 C6H5P:1 S) in sehr guter Ausbeute und Reinheit erhalten. Weitere neue Darstellungswege sind die Komproportionierung von 2 und (C6H5PS)3 sowie die Reaktion von Dikalium-triphenyl-cyclotriphosphid (4) mit Schwefeldichlorid. Das IR- und das 31P-NMR-Spektrum der Verbindung sind ein eindeutiges Indiz für die Heterocyclophosphan-Struktur 1 mit fünfgliedrigem P4S-Ring. Die besondere Stabilität dieses Molekelgerüstes geht aus der größeren Zahl weiterer Bildungs-Reaktionen für 1 hervor, über die außerdem berichtet wird.
    Additional Material: 2 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 380 (1971), S. 37-40 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Borates of the compositions formulated above are prepared in crystalline form by cooling their molten solutions in the corresponding borate M2+O · xB2O3. Some properties of the compounds are reported.
    Notes: Die Borate M2+Sn(BO3)2 (M = Mg, Ca, Sr, Ba, Cd, Mn, Co), M2+Zr · (BO3)2 (M = Ca, Sr, Ba, Cd) und BaTi(BO3)2 werden durch Abkühlen einer schmelzflüssigen Lösung in einem Überschuß des jeweiligen Borates M2+O · xB2O3 in kristalliner Form dargestellt. Einige Eigenschaften der Verbindungen werden mitgeteilt.
    Additional Material: 2 Tab.
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  • 7
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and crystal growth of halogenotungstates and halogenomolybdates from molten salt solutions are described. Characteristic properties of this new class of compounds are communicated.
    Notes: Darstellung und Züchtung größerer Kristalle der Halogenowolframate und Halogenomolybdate MeO · MeAO4 · nMeX2 (Me = Ca, Sr, Ba; A = Mo, W; n = 1, 1,5; 2; X = Cl, Br) aus Schmelzlösungen werden beschrieben. Einige charakteristische Eigenschaften dieser neuen Klasse von Verbindungen werden angegeben.
    Additional Material: 1 Tab.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 396 (1973), S. 1-6 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Hydrazine and its Derivatives. XXXVI. On the Pernitrides and Nitrogen Complexes of Barium, Strontium, and CalciumFor further characterization of the alkaline earth pernitrides M3N4 (M = Ba, Sr, Ca) as well as the alkaline earth-nitrogen complexes, which can be obtained from them, magnetical studies were carried out. Whereas barium and calcium pernitride show paramagnetism and strontium pernitride weak diamagnetism, the nitrogen complexes are diamagnetic. The barium-nitrogen complex was treated with carbon monoxide under high pressures at different temperatures. Although no exact ligand exchange occurred, a partial addition of the CO molecule was noticed. By reaction of barium pernitride with carbon monoxide at 250°C and 450 at barium cyanide was produced in high yield.
    Notes: Zur weiteren Charakterisierung der Erdalkalimetallpernitride Me3N4 (Me = Ba, Sr, Ca) sowie der daraus darstellbaren Erdalkalimetall-Stickstoff-Komplexe wurden magnetische Untersuchungen durchgeführt. Während Barium- sowie Calciumpernitrid Paramagnetismus und Strontiumpernitrid schwachen Diamagnetismus aufwiesen, sind die Stickstoff-Komplexe diamagnetisch. Der Barium-Stickstoff-Komplex wurde unter hohen Drücken bei verschiedenen Temperaturen mit Kohlenmonoxid umgesetzt, wobei zwar kein echter Ligandenaustausch, wohl aber eine teilweise Addition der CO-Molekel beobachtet werden konnte. Die Behandlung von Bariumpernitrid mit Kohlenmonoxid bei etwa 250°C und 450 at liefert in hoher Ausbeute Bariumcyanid.
    Additional Material: 2 Tab.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 397 (1973), S. 31-39 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hexakis(trifluorophosphine) Complexes of Chromium(0), Molybdenum(0), and Tungsten(0)The reaction of tris(π-allyl)chromium with PF3 at low pressure yields deep darkgreen tris(π-allyl)-trifluorophosphine chromium which is slowly converted into hexakis(trifluorophosphine) chromium: If tris(π-allyl)chromium is reacted with PF3 at high pressure, the only isolable product is Cr(PF3)6. Anhydrous molybdenum(V) and tungsten(VI) chloride react with PF3 in the presence of copper to the hexakis(trifluorophosphine) complexes of the zerovalent metals: The hexakis(trifluorophosphine) complexes are thermally very stable, crystalline, colourless solids.
    Notes: Eine ätherische Lösung von Tris(π-allyl)-chrom setzt sich unter geringem Trifluorphosphindruck zu tief dunkelgrünem Tris(π-allyl)-trifluorphosphinchrom um, das langsam zu kristallinem, farblosen Hexakis(trifluorphosphin)-chrom(0) weiterreagiert: Bei den Hochdruckumsetzungen des kristallinen Tris(π-allyl)-chrom konnte nur das Endprodukt Cr(PF3)6 isoliert werden. Wasserfreies Molybdän(V)-chlorid und Wolfram(VI)-chlorid bilden in Gegenwart von Kupfer als halogenbindendem Beimetall unter Trifluorphosphindruck die ebenfalls kristallinen, farblosen Hexakis(trifluorphosphin)-metall(0)-Komplexe: .
    Additional Material: 1 Ill.
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  • 10
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fluorine Exchange in Trifltiorophosphinemetal Complexes. IVThe Reaction of Nitrosyltrifluorophosphirie Complexes of Iron and Cobalt with Alkoxid- and Hydroxid-IonsFe(NO)2(PF3)2, 1, and Co(NO)(PF3)3, 2, react with alcoxids and phenoxid by a complete F/OR-exchange to the corresponding phosphite complexes Fe(NO)2P(OR)3)2 and Co(NO)(P(OR)3)3, (R = CH3, C2H5, n-C3H7, i-C3H7, n-C4H9, C6H5), 3-13. The nitrosyltrifluorophosphine complexes 1 and 2 change only one or two fluorine atoms against OH--ions to give difluorophosphito complexes: The reaction of 1 with a diisopropylamine/water mixture yields the bis(difluorophosphito) complex [Fe(NO)2(PF2O)2]2-, 15, with 2 under identical conditions [Co(NO)(PF3)2 PF2O]-, 14, is obtained; 1 and 2 react with Ba(OH)2 in THF to give [Fe(NO)2(PF3)PF2O]- resp. 14, the latter reacts under harder conditions partially to [Co(NO)(PF3)(PF2O)2]2-. These difluorophosphito complexes, which are isolated as salts with the cations [(i-C3H7)2NH2]+ and Ba2+, can be alkylated to the corresponding difluorethoxyphosphine derivates of 1 and 2, Fe(NO)2 (PF3)2-n(PF2OC2H5)n (n = 1,2) and Co(NO)(PF3)2PF2OC2H5. All compounds are characterised by IR and mass spectra.
    Notes: Fe(NO)2(PF3)2, 1, und Co(NO)(PF3)3, 2, tauschen bei der Umsetzung mit Alkoholaten und Phenolat sämtliche Fluoratome gegen RO-Gruppen aus unter Bildung der entsprechenden Phosphitkomplexe Fe(NO)2(P(OR)3)2 bzw. Co(NO)(P(OR)3)3 (R = CH3, C2H5, n-C3H7, i-C3H7, n-C4H9, C6H5), 3-13. Beide Nitrosyl-trifluorphosphin-Komplexe gehen maximal nur einen zweifachen F/OH-Austausch zu Difluorphosphito-Komplexen ein: In einem Diisopropylamin/Wasser-Gemisch liefert 1 den Bis(difluorphosphito)-Komplex[Fe(NO)2(PF2O)2] 2-, 15, 2 unter gleichen Bedingungen [Co(NO)(PF3)2PF2O- 14; die Umsetzung von 1 und 2 mit Ba(OH)2 in Tetrahydrofuran führt zu [Fe(NO)2(PF3) PF2O]- bzw. 14, welches sich unter drastischen Bedingungen teilweise zu [Co(NO)(PF3) (PF2O)2]2- umsetzt. Diese Difluorphosphito-Komplexe, die als Salze mit den Kationen [(i-C3H7)2NH2]+ bzw. Ba2+ anfallen, können zu den entsprechenden Difluoräthoxy-Derivaten von 1 und 2, Fe(NO)2 (PF3)2-n(PF2OC2H5)n (n = 1, 2) bzw. Co(NO)(PF3)2PF2OC2H5, alkyliert werden. Sämtliche Verbindungen werden anhand der IR- und Massenspektren charakterisiert.
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