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Mohsin Ali Chaudry Christian Woitzik Christian Weißenfels Alexander Düster Peter Wriggers 《PAMM》2016,16(1):311-312
In this contribution, a novel design strategy is investigated for improving the crashworthiness of double-hull vessels, which involves usage of granular materials. For numerical simulation, a framework based on coupling of the Discrete Element and the Finite Element Method is used to study load bearing capacity of granular materials during uniaxial compression. In addition, the effect of Young's modulus of particles is also investigated with respect to the load transferability. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
74.
Christian Reichardt Hans-Peter Erfurt Klaus Harms 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1081-1092
Attempts at the oxidation of 3-ethyl-2-methylbenzothiazolium salt 2 with a variety of oxidizing reagents did not lead to the desired isochiral S -oxide 3 or achiral S , S -dioxide 4 , in some cases, however, unexpectedly to the ring-opened dimeric 2,2'-di( N -ethyl-acetamino)substituted diphenyl disulfane 5 , the molecular structure of which was confirmed by x-ray analysis. The synthesis of 2-methylbenzothiazole- S , S -dioxide 14 , reported by Zincke et al. in 1915, turned out to be not reproducible. \centerline{\epsfbox{:art:fig-01.jpg}} 相似文献
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Isaías Juárez-Ramírez Edgar Moctezuma Leticia M. Torres-Martínez Christian Gómez-Solís 《Research on Chemical Intermediates》2013,39(4):1523-1531
The deposition of TiO2 nanoparticles on SiC was carried out by mechanical milling under different conditions. SiC–TiO2 samples were used as photocatalysts for the degradation of organic dyes such as methylene blue and rhodamine B. A short time deposition of TiO2 nanoparticles was observed during mechanical milling (2 min at 200 rpm) to cover the SiC particles. The presence of SiC and TiO2 (anatase and rutile) was confirmed by means of X-ray diffraction after thermal treatment at 450 °C. The deposition of TiO2 on SiC was corroborated by scanning electron microscopy analysis; the thickness of the thin layer of TiO2 deposited on SiC increases as the proportion of TiO2 increases. The energy band gap values obtained for these compounds were around 3.0 eV. SiC–TiO2 photocatalysts prepared by mechanical milling exhibited better activity under UV-light irradiation for the degradation of methylene blue and rhodamine B than commercial TiO2 powder (titania P25). 相似文献
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Prof. Dr. Sjoerd Harder Dominik Naglav Dr. Christian Ruspic Prof. Dr. Claudia Wickleder Dr. Matthias Adlung Dr. Wilfried Hermes Dr. Matthias Eul Prof. Dr. Rainer Pöttgen Dr. Daniel B. Rego Prof. Dr. Frederic Poineau Prof. Dr. Kenneth R. Czerwinski Prof. Dr. Rolfe H. Herber Prof. Dr. Israel Nowik 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(37):12173-12173
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Dr. Nina Schützenmeister Dr. Michael Müller Prof. Dr. Uwe M. Reinscheid Prof. Dr. Christian Griesinger Dr. Andrei Leonov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17584-17588
Here we report the synthesis of all four stereoisomers of mefloquine. Mefloquine (Lariam) is an important anti‐malaria drug that is applied as a racemate of the erythro form. However, the (?)‐isomer induces psychosis, while the (+)‐enantiomer does not have this undesired side effect. There are six syntheses of which five lead to the wrong enantiomer without the authors of these syntheses noting that they had synthesized the wrong compound. At the same time physical chemistry investigations had assigned the absolute configuration correctly and the last enantioselective synthesis that took these results into account delivered the correct absolute configuration. Since various synthetic approaches failed to provide the correct stereoisomers in previous syntheses, we submit here a synthetic approach with a domino Sonogashira‐6π‐electrocyclisation as key step that confirmed synthetically the correct absolute configuration of all four isomers. 相似文献
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Dr. Anna‐Barbara Gerber Prof. Christian J. Leumann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):6990-7006
We present the synthesis of the isobicyclo‐DNA building blocks with the nucleobases A, C, G and T, as well as biophysical and biological properties of oligonucleotides derived thereof. The synthesis of the sugar part was achieved in 5 steps starting from a known intermediate of the tricyclo‐DNA synthesis. Dodecamers containing single isobicyclo‐thymidine incorporations, fully modified A‐ and T‐containing sequences, and fully modified oligonucleotides containing all four bases were synthesized and characterized. Isobicyclo‐DNA forms stable duplexes with natural nucleic acids with a pronounced preference for DNA over RNA as complements. The most stable duplexes, however, arise by self‐pairing. Isobicyclo‐DNA forms preferentially B‐DNA‐like duplexes with DNA and A‐like duplexes with complementary RNA as determined by circular dichroism (CD) spectroscopy. Self‐paired duplexes show a yet unknown structure, as judged from CD spectroscopy. Biochemical tests revealed that isobicyclo‐DNA is stable in fetal bovine serum and does not elicit RNaseH activity. 相似文献
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