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41.
The laser-induced thermal acoustics (LITA) method was used to measure the temperature profiles induced behind spherical shock
waves, generated by high-voltage discharge in air with an energy of 6 J. A Nd:YAG laser (wavelength 532 nm, energy 300 mJ,
pulse duration 10 ns, line width 0.005 cm−1) and an Ar-ion laser (wavelength 488 nm, power 4 W) served as the pump and probe lasers, respectively for the LITA measurements.
The peak temperatures were in good agreement with results calculated with the Euler equations. The temperature profiles behind
the shock, however, differed in decay rates. The peak temperatures behind the shock wave were determined by reflected overpressure
and agreed with those from the LITA measurements within a maximum error of 5%. 相似文献
42.
Tatsuro Ouchi Shinji Kitazaki Akinobu Kobayashi Minoru Imoto 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(7):1045-1059
The radical polymerization of methyl methacrylate (MMA) was carried out with the system of imidazole (Im), copper(n) chloride, and water at 85°C. The effects of the amount of each component on the conversion of MMA were investigated. The polymerization proceeded through a radical mechanism. The overall activation energy was estimated to be 28.7 kJ/mole. The conversion of MMA showed a maximum at pH 8-9 of the aqueous solution. The formation of a complex of CuCl2 with Im, water, and MMA was confirmed by electronic spectra. An initiation mechanism was proposed. 相似文献
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44.
Kanako Nozawa-Kumada Satoshi Saga Yuta Matsuzawa Masahito Hayashi Masanori Shigeno Yoshinori Kondo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(20):4496-4499
β-Lactams are important structural motifs because of their ubiquity in natural products and pharmaceuticals. We report herein a Cu-catalyzed intramolecular oxidative C(sp3)−H amidation for the synthesis of β-lactams using tBuOOtBu. This method is based on Kharasch–Sosnovsky amidation and does not require prefunctionalization of C(sp3)−H bonds or the installation of a directing group, thereby allowing for the straightforward synthesis of β-lactams. Our intramolecular functionalization protocol can be extended to diverse benzylic C(sp3)−H bonds and shows excellent functional-group tolerance. 相似文献
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47.
Summary First, the effect of micro-gels, which formed in the aqueous solution of syndiotacticity-rich PVA(s-PVA) of higher molecular weight under quiescence, on the flow-induced crystallization was examined. The gel panicles which formed under quiescence did not play a role as seed crystals for the flow-induced crystallization. Second, for s-PVA of lower molecular weight, the productions of particles under quiescence and flow in the aqueous solutions were compared.cf. part XXXVI. K. Yamaura, Y. Okumura, S. Matsuzawa, J. Macromol. Sci.(-Phys.), in press.Dedicated to Professor Dr. K. Ueberreiter on his 70th birthday. 相似文献
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Tadato Matsuzawa 《偏微分方程通讯》2013,38(11):1059-1084
50.
Organotin perfluorooctanesulfonates as air-stable Lewis acid catalysts: synthesis, characterization, and catalysis 总被引:1,自引:0,他引:1
An de L Peng Z Orita A Kurita A Man-e S Ohkubo K Li X Fukuzumi S Otera J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(6):1642-1647
The reactions of 1,3-dichloro-1,1,3,3-tetrabutyldistannoxane and dialkyltin dihalides with silver perfluorooctanesulfonate provided the corresponding sulfonates as hydrates. The number of water molecules (n) of hydration was dependent on the conditions. The distannoxane derivative was identified as n from 0.5 to 6, while in the hydrated mononuclear species and DMSO complexes n varied widely from 4 to 13. 119Sn NMR spectroscopy and conductivity measurements indicated the ionic dissociation of these compounds in solution. These compounds exhibited unusually high solubility in polar organic solvents. The ionic dissociation together with facile hydration probably causes the unusual solubility. The Lewis acidity of these compounds was found to be high among organotin derivatives on the basis of ESR spectra of superoxide/metal-ion complexes. In contrast to well-known organotin triflates, these compounds suffered no hydrolysis upon storage in open air. The high catalytic activity of the distannoxane 1 was exemplified for various carbon-carbon bond-forming reactions, such as Mukaiyama-aldol as well as -Michael reactions and allylation of aldehydes. 相似文献