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91.
Dithioacetal monoxides were synthesized from aldehydes and cyclohexanone, and reaction of the dithioacetal monoxides with Grignard reagents was investigated. The dithioacetal monoxide synthesized from alkylaldehyde and 4-chlorobenzenethiol reacted with i-PrMgCl to afford the desired alpha-thiomagnesium in high yield. The generated alpha-thiomagnesium was found to be stable at room temperature and to be useful in organic synthesis. In contrast to this, the dithioacetal monoxides derived from benzaldehyde and cyclohexanone did not give satisfactory results. 相似文献
92.
Murakami T Nishikiori T Nohira T Ito Y 《Journal of the American Chemical Society》2003,125(2):334-335
Ammonia was successfully synthesized by using a new electrochemical reaction with high current efficiency at atmospheric pressure and at lower temperatures than the Haber-Bosch process. In this method, nitride ion (N3-), which is produced by the reduction from nitrogen gas at the cathode, is anodically oxidized and reacts with hydrogen to produce ammonia at the anode. 相似文献
93.
Profile structure of magnetic flux lines in type-II superconductor from a rectangular electron hologram 总被引:1,自引:0,他引:1
Harada K Beleggia M Endo J Kasai H Togawa Y Matsuda T Tonomura A 《Journal of electron microscopy》2003,52(4):369-373
Profile magnetic configuration of a quantized flux line and flux-line lattice penetrating a type-II superconductor thin foil, niobium, was observed by electron holography and Lorentz microscopy using a 300 kV field-emission electron microscope. Each single flux line was distributed periodically as lattice structure in the mixed state just below its critical temperature of 8.5 K, while at low temperature of 5 K the flux lines were weakly bound as bundles. In order to observe the flux-line distribution over a wide area, discrete Fourier transform reconstruction in the holography was extended for a rectangular area without loss of information and data precision. 相似文献
94.
Takaya Terashima Makoto Ouchi Tsuyoshi Ando Mitsuo Sawamoto 《Journal of polymer science. Part A, Polymer chemistry》2011,49(5):1061-1069
Oxidation of sec‐alcohols was investigated with ruthenium‐bearing microgel core star polymer catalysts [Ru(II)‐Star]. The star polymer catalysts were directly prepared via RuCl2(PPh3)3‐catalyzed living radical polymerization of methyl methacrylate (MMA), followed by the arm‐linking reaction with ethylene glycol dimethacrylate ( 1 ) in the presence of diphenylphosphinostyrene ( 2 ). The Ru(II)‐Star efficiently and homogeneously catalyzed the oxidation of 1‐phenylethanol ( S1 ) to give a corresponding ketone (acetophenone) in higher yield (92%) than the analogs of polymer‐supported ruthenium complexes. Importantly, the star catalyst afforded high recycling efficiency in the oxidation. They held catalytic activity against three times catalysis even though they were recovered under air‐exposure, whereas the conventional RuCl2(PPh3)3 lost the activity for same recycling procedure due to the deactivation by oxygen. The stability of the star catalysts during the recycle experiment was confirmed by detailed spectroscopic characterization. The star polymers also catalyzed oxidation for a wide range of sec‐alcohols with aromatic and aliphatic groups. The substrate affinity was different from that with RuCl2(PPh3)3, suggesting the unique selectivity caused by the specific structure. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011. 相似文献
95.
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97.
Takahiro Kawashima Tsuyoshi Kimura Takayuki Shibata Akio Kishida Takashi Mineta Eiji Makino 《Microelectronic Engineering》2010,87(5-8):704-707
In order to realize cellular network analysis on a chip-based system, our group has been developing a patterned cell culture microdevice with pillars in an array for tapping cells into space surrounded by the pillars. The pillar structures has advantages to trap both adhesive and non-adhesive cells and to precisely control positions of cells and distances between cells for understanding effects of various cell patterns on functions of a cellular network such as cell proliferation, differentiation, and network formation. In this paper, HeLa cell cultivation with the patterned cell culture microdevice having a pillar array fabricated by dry film of thick negative photoresist SU-8 on a glass substrate was executed as a feasibility study on a cellular network analysis. The results revealed that the device performance was found to be enough to culture HeLa cells for more than 48 h. In addition, relative extensibility of blocks of multiple cells compared with single cells tapped on the device was observed. Thus, the patterned cell culture microdevice proposed here could be applicable to analysis of cellular functions. 相似文献
98.
A finite element method for treating two-dimensional electron systems with Rashba spin–orbit interaction is developed. The Rashba spin–orbit interaction removes spin degeneracy, so that each spin contributes to the conductance differently. By accounting for the connection between a system and leads, this method yields the conductance of a nanoscale quantum device for each spin state. As an example, this calculation method is applied to a model of a quantum point contact. The results of this calculation indicate conductance quantization and a large spin polarization. We discuss the estimated accuracies of this calculation. 相似文献
99.
Tsuneyuki Sato Tsuyoshi Yamamoto Tetsuo Ogawa Takayuki Otsu 《Journal of polymer science. Part A, Polymer chemistry》1986,24(7):1519-1528
Poly[acryloyl-L-valine (ALV)] microspheres containing peroxy ester groups were prepared by radical copolymerization of ALV with a small amount of di-tert-butyl peroxyfumarate. When the microspheres were irradiated in the presence of second vinyl monomers, long-lived propagating radicals of the second monomers were formed in the microspheres by the reaction of microsphere polymer radicals with the monomers. The presence of a minute quantity of ethyl alcohol served to soften the microspheres and made the polymer radicals more mobile in the microspheres. As a result, sharper ESR spectra of the propagating radicals were observed although their lifetimes became shorter. This microsphere method also yielded easily the stable propagating radicals of a-methylstyrene and 1,1-diphenylethylene which have no homopolymerizability in usual radical polymerization. When N-n-propyldimethacroylamide and N,N′-dimethyl-N,N′-dimethacroylhydrazine, which undergo cyclopolymerization, were used as second monomer, uncyclized polymer radicals were only observed. Some discussions were given on the propagation mechanism of the cyclopolymerization. 相似文献