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91.
Fujiko Iwasaki Hideyuki Nishiyama Noriko Manabe Masanori Yasui Noboru Matsumura 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):429-430
Abstract Novel metal-carbene complexes (4) with a metallapentalene framework have been obtained from hypervalent diazadiselenathiapentalenes (3) by treating with Pt(PPh3)4, Pd(PPh3)4 and RhCl(PPh3)3. X-Ray investigations revealed that the central hypervalent sulfur atom in 3 was substituted by a metal atom to form M-Se bonds in the resultant metallapentalene framework. 相似文献
92.
Hironori Tohmyoh Shoho Ishikawa Mikio Muraoka 《Surface and interface analysis : SIA》2012,44(9):1294-1298
An eddy current microscopy technique to evaluate the electrical conductivity of thin metallic films in a non‐contact manner is reported. A narrow track formed in an approximately 100 nm thick Au film was prepared, and a Co–Cr coated magnetic tip was driven to oscillate above the track both with and without current passing through the track. Despite the absence of current, the electromagnetic interaction between the tip and the stray magnetic field from the track gave rise to a phase delay in the probe. This was due to an eddy current being induced within part of the track. Moreover, measurements of the phase change in the probe oscillation for different metallic films with thicknesses of about 100 nm found this to be proportional to the electrical conductivity of the film. Finally, the electrical conductivity of an Al film was evaluated using the eddy current microscopy technique. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
93.
Noriko Nakagawa Takafumi Yamada Koji Akioka Susumu Okubo Shojiro Kimura Hitoshi Ohta 《International Journal of Infrared and Millimeter Waves》1998,19(2):167-176
New systems for millimeter and submillimeter wave ESR have been developed in Kobe University. In the previous system the pulsed magnetic field was limited up to 17 T in the temperature range from 1.8 to 86 K. Using the new systems, we can measure in the field range up to 30 T in the temperature range from 1.8 K to 4.2 K and from 18 K to room temperature. The resolution of the magnetic field has been also improved in the new ESR system. The details of our new ESR systems are presented. In addition, the measurements of Yb2Cu2O5 using these new systems are presented. 相似文献
94.
Noriko Hirata-Kohno 《Inventiones Mathematicae》1991,104(1):401-433
Dans ce papier, nous donnons des minorations de combinaisons linéaires à coefficients algébriques de logarithmes de points algébriques sur les groupes algébriques commutatifs: soitG un groupe algébrique commutatif connexe défini sur la clôture algébriqueQ de dans , et soitvT
G
() un point de l'espace tangent dont l'image exp
G
(v) par l'exponentielle deG appartient àG(Q). On cherche à minorer la distance du pointv aux hyperplansW deT
G
(), rationnels surQ, qui ne passent pas parv. Cette minoration dépend, entre autres, d'un majorantB de la hauteur usuelle des coefficients d'une forme linéaire définissantW. LorsqueG est un groupe linéaire, il s'agit de minorer une combinaison linéaire de logarithmes de nombres algébriques, et la méthode de A. Baker permet d'obtenir une minoration
相似文献
95.
A synthesis of an advanced ABCDE ring system (24c) having characteristic substituents in both benzene rings of ecteinascidin marine natural products is described based on our model studies. 相似文献
96.
Two new triterpenoid saponins, ardisimamilloside G (1), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-13beta,28-epoxy-16-oxo-oleanan-3beta,30-diol and ardisimamilloside H (2), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-alpha-L-arabinopyranosyl]-3beta-hydroxy-13beta,28-epoxy-16-oxo-oleanan-30-al, were isolated from the roots of Ardisia mamillata HANCE. Structure assignments were established on the basis of spectral data and chemical evidence. 相似文献
97.
Yasuyoshi Miki Noriko Nakamura Hiroko Hachiken Shoji Takemura 《Journal of heterocyclic chemistry》1989,26(6):1739-1745
Treatment of 3-(hydroxymethyl)pyrazolo[1,5-a]pyridines with trifluoroacetic acid in refluxing dichloro-methane led to the formation of bis(pyrazolo[1,5-a]pyrid-3-yl)methanes or bis[(pyrazolo[1,5-a]pyrid-3-yl)]-methyl ethers depending upon the concentration of trifluoroacetic acid. In contrast, similar treatment of 3-(1-hydroxyethyl)pyrazolo[1,5-a]pyridines gave a mixture of 3-vinylpyrazolo[1,5-a]pyridines and 1,3-bis(pyrazolo-[1,5-a]pyrid-3-yl)-1-butenes. 相似文献
98.
Shingo Katayama Noriko Yamada Masanobu Awano 《Journal of Sol-Gel Science and Technology》2004,32(1-3):311-316
The preparation and NO-adsorption/desorption behavior of Li, Ca and Ba silicates were investigated aiming at the application to a NOx-absorbent. Li silicate was prepared by reaction of HSi(OC2H5)3 with aqueous lithium silicate solution (LSS). Ca and Ba silicates were prepared from gels obtained using CH3Si(OC2H5)3, Si(OC2H5)4, HSi(OC2H5)3 and alkaline-earth alkoxides. The surface of these silicates indicated the solid basicity of H0 = 9 and adsorbed the acidic gas of NO. FT-IR spectra of the silicates adsorbing NO showed the absorption peaks in the range of 1300–1600 cm– 1 corresponding to ionic and covalent nitrate NO3–. The complete desorption of adsorbed NO species occurred above 500°C in the Li silicate, above 500°C in the Ca and Ba silicates prepared using CH3Si(OC2H5)3, and above 700°C in the Ba and Ca silicates prepared using Si(OC2H5)4. Regarding the Ca and Ba silicates, the difference in siloxane structure is thought to cause the difference in adsorption state and desorption behavior of NO. 相似文献
99.
Density functional theory calculations were conducted on the title reactions with explicit inclusion of a variety of water molecules. Concerted reaction paths were examined first in the reaction model, ester(H2O)n --> MeCOOH(H2O)(n-1)EtOH, with n = 1-4. Their Gibbs activation energies are much larger than the experimental value, and the concerted paths are unfavorable. Various stepwise paths were investigated, and the ester(H2O)4 reactant gives a likely stepwise path. The n = 4 based reaction models, n = 4 + 5 and n = 4 + 12, were found to have similar proton-relay shapes with good hydrogen-bond directionality. The distinction of either the concerted or the stepwise path is described by the position of only one proton in the "junction" water molecule. 相似文献
100.
Toshiaki Sunazuka Noriko Chikaraishi Masahiko Hayashi Paul A. Sprengeler Satoshi ōmura 《Tetrahedron》2005,61(15):3789-3803
In the current studies, we used the single-crystal X-ray analysis and Kakisawa-Kashman modification of the Mosher NMR method to determine the complete relative and absolute stereochemistries of the (+)-macrosphelides A (+)-1 and B (+)-2. The stereostructure of (+)-2 was determined by chemical comparison with artificial (+)-2 from (+)-1. We also report the convergent total synthesis of (+)-1 and (+)-3, as well as their antipodes, utilizing an asymmetric dihydroxylation for introduction of chirality and Yamaguchi macrocyclization to form the 16-membered trilactone macrolides. 相似文献
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