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51.
Noguchi M Nakamura M Ohno A Tanaka T Kobayashi A Ishihara M Fujita M Tsuchida A Mizuno M Shoda S 《Chemical communications (Cambridge, England)》2012,48(45):5560-5562
An efficient chemo-enzymatic process for construction of the α-linked disaccharide unit (GlcNAcα1-4Gal) found in gastric mucin has been developed. The process consists of a one-step preparation of a novel triazine type glycosyl donor in water and the subsequent transglycosylation to a galactose derivative catalysed by α-N-acetylglucosaminidase. 相似文献
52.
Tomonari Suzuki 《Journal of Mathematical Analysis and Applications》2003,286(2):453-458
In this paper, using the notion of τ-distance, we prove a generalization of Downing-Kirk's theorem. 相似文献
53.
Hiroki Hotta Qiang Wang Mioko Fukuda Shoichi Aizawa Tomonari Umemura Kazutoshi Sekizawa Kin-ichi Tsunoda 《Analytical sciences》2008,24(6):795-798
The use of electrospray ionization mass spectrometry (ESI-MS) in negative ion mode was investigated as a direct probe for identifying Al species in Al-accumulating hydrangea (Hydrangea macrophylla) samples. Cell sap solutions of hydrangea leaves were purified using Sephadex G-10 liquid chromatography and each fraction was analyzed using ESI-MS and ESI-MS/MS to identify Al species. In hydrangea leaves, a 1:1 Al-citrate complex was found as [AlH(-1)cit](-) (m/z 215), where H(3)cit denotes citric acid. This result is consistent with that of Ma et al. who used (27)Al-NMR. 相似文献
54.
Shouhei Toyoda Yoshifumi Yamaguchi Masataka Hiwatashi Yasuhiko Tomonari Hiroto Murakami Dr. Naotoshi Nakashima Prof. 《化学:亚洲杂志》2007,2(1):145-149
We designed and synthesized 4‐dodecyloxybenzenediazonium tetrafluoroborate ( 1 ), which preferentially reacts with metallic single‐walled carbon nanotubes (SWNTs) by kinetic control. We first determined the suitable experimental conditions for the preferential reaction of 1 with individually dissolved SWNTs by monitoring the decrease in absorbance for the metallic SWNT in the range of 400–650 nm in the absorption spectrum of the SWNTs. The reacted SWNTs were thoroughly rinsed with THF to obtain THF‐insoluble SWNTs. The Raman spectrum of the THF‐insoluble SWNTs showed a strong peak near 180 cm?1, which corresponds to a semiconducting breathing band. The metallic breathing bands (≈220 cm?1) and Breit–Wingner–Fano (BWF) modes (1520 cm?1) corresponding to the metallic SWNTs were much weaker than those of the pristine SWNTs. We also confirmed that metallic peaks in the range of 400–650 nm in the absorption spectrum of THF‐insoluble SWNTs that were individually dissolved in an aqueous micelle of sodium cholate were almost nondetectable. All the results indicate that the THF‐insoluble SWNTs are semiconducting. 相似文献
55.
The influences of water and alkoxide concentrations, as well as the relative humidity upon the macroporous morphology of the titania (TiO2) films have been studied for a sol-gel dip-coating system containing poly(ethylene glycol) (PEG). The distribution of resultant morphology against the withdrawal speed and relative humidity is varied significantly by mainly modifying the polycondensation and phase separation processes during the dipping operation, even by the small change in starting composition of the dipping solution. 相似文献
56.
Tohru Sakakibara Kiyotaka SuzukiAkiko Sakai Miwa ShindoChihiro Nagano Shinya NarumiYasuhiro Kajihara Katsura Mochizuki 《Tetrahedron letters》2003,44(30):5711-5714
Methyl 4,6-O-benzylidene-2,3-dideoxy-3-C-p-tolylsulfonyl-2-C-p-tolylthio-β-d-glucopyranoside and its 5a-carba-dl-analog exit mainly in a non-chair conformation in solutions, but the latter occupies a chair conformation in a solid state. 相似文献
57.
A diastereomeric (epimeric) mixture of ethylmethylphenyltelluronium (1S)-(+)-camphor-10-sulfonate (dia.-1) was optically resolved by fractional recrystallization into the diastereomerically pure isomers (R)(Te)-1 and (S)(Te)-1. The absolute configurations of the isomers were determined by the X-ray crystallographic analysis of (R)(Te)-1. Enantiomerically pure (R)-ethylmethylphenyltelluronium perchlorate, tetrafluoroborate, p-chlorobenzenesulfonate, bornane-10-sulfonate, tetraphenylborate, and picrylsulfonate (R)-2-7 were isolated, respectively, by anion-exchange reactions of diastereomerically pure (R)(Te)-1. The optically active telluronium salts were found to show peculiar optical properties on their specific rotations and circular dichroism spectra in solutions compared with those of the corresponding sulfonium and selenonium salts. On the basis of NMR studies, the behavior on the optical properties of the optically active telluronium salts was found to be caused by a strong solvation in polar solvents. 相似文献
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