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81.
Harada A Enomoto K Takahide Y Kimata M Yakabe T Kodama K Satsukawa H Kurita N Tsuchiya S Terashima T Uji S 《Physical review letters》2011,107(7):077002
We report the first observation of a single-vortex flow in a mesoscopic superconductor. A flow of a single vortex is successfully controlled by an rf current superimposed on a dc current, evidence of which is provided by voltage steps in current-voltage (I-V) characteristics. Irrespective of the number of vortices confined to the disk, we unambiguously observe that when a single vortex inside the disk is driven out of the disk, another vortex enters the disk similarly to two balls colliding in billiards: only one vortex passes through the Al disk at the same time in mesoscopic systems. 相似文献
82.
Takahide Nishiyama Fumihiro Endo Hiroko Eguchi Tatsuro Nakagama Nobuko Seino Masaki Shinoda Takuya Shimosaka Toshiyuki Hobo Katsumi Uchiyama 《Analytical sciences》2007,23(4):389-393
An ultra-micro sample injector for gas chromatography (GC) was developed. An ink-jet microchip, originally used for industrial recorder, was modified at the edge near to an orifice, and fixed into the GC. In order to evaluate the characteristics of this injector, a sample injector and a thermal conductive detector (TCD) were connected directly, while water was used as the test sample. The volume of the droplet, the interval time and the back-pressure to the ink-jet microchip were investigated. Within the range of 1 - 5 nL volume injected sample, the TCD response according to the amount of the sample volume (the volume of one droplet from the ink-jet microchip was about 1 nL) was obtained. A good reproducibility of the peak area was obtained to be about 1.0% of the RSD value. In order to compare the injection method of the ink-jet chip with that using a micro-syringe, the method using the ink-jet chip could introduce 1/1000 of the amount of the sample and gave reproducible results. 相似文献
83.
[reaction: see text] Substitution at nitrogen by alpha,beta-unsaturated acyl radicals took place accompanied by elimination of an alpha-phenethyl radical. This reaction led to the development of a new carbonylative annulation method for five- to seven-membered ring lactams. 相似文献
84.
Ruthenium catalyzes a carbonylative [3+2+1] cycloaddition, using silylacetylenes, alpha,beta-unsaturated ketones, and CO as the starting materials, providing the new method for the synthesis of tetrasubstituted alpha-pyrones. In this reaction, the carbonyl group and alpha-carbon of vinyl ketones are incorporated as a three-atom assembling unit. [reaction: see text]. 相似文献
85.
Lemière G Gandon V Cariou K Fukuyama T Dhimane AL Fensterbank L Malacria M 《Organic letters》2007,9(11):2207-2209
We have developed an expedient method for the synthesis of polycyclic compounds from propargyl acetates or vinyl allenes involving up to three Au(I)-catalyzed elemental steps: 3,3-rearrangement, metalla-Nazarov reaction, and electrophilic cyclopropanation. The reaction proceeds under very mild conditions and in short times. The mechanism has been studied by DFT computations. 相似文献
86.
The effect of heterogeneous solvent systems on sonochemical reactions: accelerated degradation of alkyl thiols in emulsion 总被引:1,自引:0,他引:1
Sonochemical reactions of alkyl and aryl thiols in water–organic mixed solvent systems were kinetically investigated. The reaction in the liquid–liquid interface apparently depends on the polarities, surface activities, vapor pressures and hydrophobicities of organic solvents and thiols. Interestingly, the rate jump in sonochemical disappearance of alkyl thiols was observed under emulsified conditions. 相似文献
87.
Dr. Akira Fusano Shuhei Sumino Satoshi Nishitani Takaya Inouye Keisuke Morimoto Dr. Takahide Fukuyama Prof. Ilhyong Ryu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(30):9415-9422
The atom‐transfer carbonylation reaction of various alkyl iodides thereby leading to carboxylic acid esters was effectively accelerated by the addition of transition‐metal catalysts under photoirradiation conditions. By using a combined Pd/hν reaction system, vicinal C‐functionalization of alkenes was attained in which α‐substituted iodoalkanes, alkenes, carbon monoxide, and alcohols were coupled to give functionalized esters. When alkenyl alcohols were used as acceptor alkenes, three‐component coupling reactions, which were accompanied by intramolecular esterification, proceeded to give lactones. Pd‐dimer complex [Pd2(CNMe)6][PF6]2, which is known to undergo homolysis under photoirradiation conditions, worked quite well as a catalyst in these three‐ or four‐component coupling reactions. In this metal/radical hybrid system, both Pd radicals and acyl radicals are key players and a stereochemical study confirmed the carbonylation step proceeded through a radical carbonylation mechanism. 相似文献
88.
Kimura T Harada H Ando T Fujita M Levêque JM Luche JL 《Chemical communications (Cambridge, England)》2002,(11):1174-1175
Among the sonolysis products of acetic acid, oxidizing intermediates can play a direct role in reactions run in this solvent, illustrating the fact that organic sonochemistry can originate in organic solvents as aqueous sonochemistry can in water. 相似文献
89.
The samarium(II) iodide mediated reaction of N,N-dibenzyl-protected (S)-alpha-amino aldehydes with (1S,2R)-N-methylephedrinyl acrylate gave the (4R,1'S)-gamma-(aminoalkyl)-gamma-butyrolactones in good yields with high diastereoselectivities (up to 80% de); (4R,1'S)-gamma-amino-(2-phenylethyl)-gamma-butyrolactone (6a), which should be a potent precursor for gamma-secretase inhibitors, was obtained with high de value. 相似文献
90.
Iodination of unactivated aliphatic hydrocarbons with iodoform (CHI3) and solid NaOH were greatly accelerated under ultrasonic irradiation. The mechanism of the sonochemical acceleration was studied. 相似文献