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31.
At temperatures above the brittle-to-ductile transition (490 °C) in Te-doped GaAs three types of predominant defect configurations have been observed after uniaxial compression along a [001] direction: (i) twins and stacking faults (500 … 520 °C), (ii) slip zones of dislocations (≈ 550 °C) and (iii) dislocation cells (580 … 590 °C). In Part I quantitative details of the appearance of twins and stacking faults are given. Most frequently found were 30° partials in twins and stacking faults. 相似文献
32.
At temperatures above the brittle-to-ductile transition (490 °C) in Te-doped GaAs three types of predominant defect configurations have been observed after uniaxial compression along a [001] direction: (i) twins and stacking faults (500 … 520 °C), (ii) slip zones of dislocations (≈550 °C) and (iii) dislocation cells (580 … 590 °C). In Part II quantitative details of the appearance of slip and cell formation are given. Leading segments of gliding half loops are mainly of 60° type. Cell walls were formed by multiple slip of perfect dislocations. 相似文献
33.
Steffen Fischer Katrin Thümmler Katy Pfeiffer Tim Liebert Thomas Heinze 《Cellulose (London, England)》2002,9(3-4):293-300
Molten inorganic salt hydrates are highly efficient solvents forcellulose. The carboxymethylation of the polymer dissolved in this new group ofcellulose solvents was investigated. The homogeneous carboxymethylation ofcellulose in molten LiClO43H2O using sodiummonochloroacetate in the presence of NaOH is possible. The formation of CMC wasconfirmed by FT- Raman spectroscopy. Structure analysis by means of HPLC afterchain degradation showed the formation of CMC with a DS of 2 after a shortreaction time of 4 h. The derivatives exhibit a statisticaldistribution of substituents along the polymer chain if prepared in moltenLiClO43H2O as solvent. A substituent distributioninthe order C-6 > C-2 C-3 for anhydroglucose units (AGU) was concludedfrom 1H-NMR measurements. The synthesis of CMC in the swellingmediumLiClxH2O (2 x 5) yields polymers with astatistical distribution of functional groups along the chain. The watercontentof the salt melts has a dramatic influence on the DSCMC. 相似文献
34.
Synthesis and Isolation of the Titanium–Scandium Endohedral Fullerenes—Sc2TiC@Ih‐C80, Sc2TiC@D5h‐C80 and Sc2TiC2@Ih‐C80: Metal Size Tuning of the TiIV/TiIII Redox Potentials
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Katrin Junghans Dr. Kamran B. Ghiassi Nataliya A. Samoylova Qingming Deng Marco Rosenkranz Prof. Marilyn M. Olmstead Prof. Alan L. Balch Dr. Alexey A. Popov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(37):13098-13107
The formation of endohedral metallofullerenes (EMFs) in an electric arc is reported for the mixed‐metal Sc–Ti system utilizing methane as a reactive gas. Comparison of these results with those from the Sc/CH4 and Ti/CH4 systems as well as syntheses without methane revealed a strong mutual influence of all key components on the product distribution. Whereas a methane atmosphere alone suppresses the formation of empty cage fullerenes, the Ti/CH4 system forms mainly empty cage fullerenes. In contrast, the main fullerene products in the Sc/CH4 system are Sc4C2@C80 (the most abundant EMF from this synthesis), Sc3C2@C80, isomers of Sc2C2@C82, and the family Sc2C2 n (2 n=74, 76, 82, 86, 90, etc.), as well as Sc3CH@C80. The Sc–Ti/CH4 system produces the mixed‐metal Sc2TiC@C2 n (2 n=68, 78, 80) and Sc2TiC2@C2 n (2 n=80) clusterfullerene families. The molecular structures of the new, transition‐metal‐containing endohedral fullerenes, Sc2TiC@Ih‐C80, Sc2TiC@D5h‐C80, and Sc2TiC2@Ih‐C80, were characterized by NMR spectroscopy. The structure of Sc2TiC@Ih‐C80 was also determined by single‐crystal X‐ray diffraction, which demonstrated the presence of a short Ti=C double bond. Both Sc2TiC‐ and Sc2TiC2‐containing clusterfullerenes have Ti‐localized LUMOs. Encapsulation of the redox‐active Ti ion inside the fullerene cage enables analysis of the cluster–cage strain in the endohedral fullerenes through electrochemical measurements. 相似文献
35.
Zoltán M. Balogh Katrin Fässler Ioannis D. Platis 《Journal d'Analyse Mathématique》2011,113(1):265-291
We develop a method using the modulus of curve families to study minimisation problems for the mean distortion functional
in the class of finite distortion homeomorphisms. We apply our method to prove extremality of the spiral-stretch mappings
defined on annuli in the complex plane. This generalises results of Gutlyanskiĭ and Martio [12] and Strebel [23]. 相似文献
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P. Hoffmann Th. Hofmann N. Pilz und K. H. Lieser 《Fresenius' Journal of Analytical Chemistry》1985,320(7):652
Ohne Zusammenfassung
Determination of actinides by x-ray fluorescence analysis, excitation by -emitters相似文献