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Zusammenfassung Im Bereich der homogenen Mischphase V1,00–0,47Al0,00–0,53 wird die metastabile Kristallart V3Al erfaßt. V3Al besitzt Cr3O-Struktur (-Wolfram-Typ). Lückenlose Mischreihen von V3Al mit V3Sb und Nb3Sn werden nachgewiesen. Unter gleichen Bedingungen, Homogenisierung bei 1000 und 1100°C, treten dagegen mit V3Si, V3Ge und Nb3Al Mischungslücken auf.Mit 1 Abbildung 相似文献
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Zusammenfassung Mittels homogenisierter Sinter-und Schmelzproben wird die Bildung von lückenlosen Mischreihen zwischen Nb3Sn mit Mo3Si, Mo3Ge und Nb3Ge nachgewiesen.Mit 1 Abbildung 相似文献
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J. von Schroeder A. Bartel W. Schmitz-Dumont und F. Simand 《Fresenius' Journal of Analytical Chemistry》1897,36(1):202-206
Ohne Zusammenfassung 相似文献
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Adolf Krebs Walter Cholcha Michael Müller Theophil Eicher Herald Pielartzik Hansgeorg Schnöckel 《Tetrahedron letters》1984,25(44):5027-5030
A six-membered and two seven-membered cycloalkynes, namely 1 – 3, are generated by matrix photolyses of the corresponding cyclopropenones 4 – 6 at about 15 K and characterized by spectroscopic means and in two cases by identification of the trimerization products 9 and 10. 相似文献
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Synthesis of Betenamine and of Betalaine Model Substances For comparisons of color, spectroscopic properties, pKa values, and stabilities, a number of model substances containing the 1,7-diazaheptamethinium chromophore 8 of the yellow and red betalaine plant pigments were prepared by the thermal or photolytic ring opening of simple pyridine derivatives (such as 2 and 14-16 ), followed by the introduction of amines. Among the novel compounds prepared were betenamine perchlorate ( 5 ), the ‘naked’ ring system of the beet-pigment betanine ( C ) as well as two 1,7-diazaheptamethinium salts 25 and 27 with terminal amono acids. The synthesis of 5 started with 4-(2-aminoethyl)pyridine ( 1 ) and proceeded via 2 , ring opening with indoline to 4 , saponification, and intramolecular amine replacement (Scheme 1). The syntheses of 25 and 27 involved only one step, namely ring opening of γ-picoline using (S)-cyclodopa ( 24 ) and (S)-proline ( 26 ), respectively (Scheme 3). 相似文献
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Associated -phosphinodiborane, (-H2PB2H5)
n
, is formed in the reaction of H2P(BH3)2Na with HCl in diethyl ether solution at –96°C. The formation of B–H–B bridges is demonstrated by IR and11B-NMR spectra. (-H2PB2H5)
n
decomposes thermally to diborane and polymeric phosphinoborane analogous to -H2NB2H5. Other phosphorus substituted -phosphinodiboranes associated via B–H–B bridges are formed in the reaction of the salts (CH3)PH(BH3)2Li, (CH3)2P(BH3)2Li, andPhPH(BH3)2Li with HCl.
Mit 6 Abbildungen
Herrn Professor Dr.E. Hayek zum 70. Geburtstag gewidmet. 相似文献
Mit 6 Abbildungen
Herrn Professor Dr.E. Hayek zum 70. Geburtstag gewidmet. 相似文献
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Th. Rosenbladt 《Fresenius' Journal of Analytical Chemistry》1887,26(1):15-18
Ohne ZusammenfassungSt. Petersburg, 20. April 1886. 相似文献
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Amidometallates of Lanthanum and Gadolinium and the Conversion of Lanthanum, Gadolinium, and Scandium with Ammonia By reaction of the metals with NsNH2 and NH3 in the hightemperature- autoclave Na3[La(NH2)6], Na3[Gd(NH2)6], and Na[Gd(NH2)4] were prepared, but not any compound of Sc. By corresponding experiments with NH4I only La(NH2)3, GdN, and ScH2 were obtained. Na3[La(NH2)6] and Na3[Gd(NH2)6] are isotypic with Na3[Y(KH2)6], Na[Gd(NH2)4] with Na[Yb((NH2)4]. The thermal behaviour of the prepared amides was characterized by DTA and tensimetry. 相似文献
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H. Kurtenacker 《Fresenius' Journal of Analytical Chemistry》1964,204(6):439
Ohne Zusammenfassung 相似文献
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Annemarie Hollstein 《Fresenius' Journal of Analytical Chemistry》1961,183(5):384
Ohne Zusammenfassung 相似文献
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The fluorination of perfluoroalkyliodides: preparation and properties of perfluoroalkyliodine-difluorides and perfluoroalkyliodine-tetrafluorides. The perfluoroalkyliodine-difluorides RIF2 (R = CF3, C2F5, C3F7) may be prepared by the direct fluorination of perfluoroalkyliodides at −78°C in CCl3F in high yields. From the fluorination at ca. −40°C the perfluoroalkyliodine-tetrafluorides RIF4 are formed as final products. The preparation and properties are described. 相似文献