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101.
Shigenobu Hayashi Fumiyuki Hoshi Takefumi Ishikura Motoo Yumura Satoshi Ohshima 《Carbon》2003,41(15):3047-3056
13C NMR spectra and spin-lattice relaxation times were measured for single-wall carbon nanotubes with 99.9 and 50.0% 13C enrichments and natural abundance (1.1% 13C) prepared by catalytic decomposition of CH4. The 13C isotropic shift is about 116 ppm from tetramethylsilane, being estimated from magic-angle-spinning (MAS) spectra. The value does not depend on the degree of the 13C enrichment. The 13C MAS NMR spectra show two additional small peaks at 171 and 152 ppm, which are ascribed to carbon species at defects or edges. The line widths of the main isotropic peak in MAS spectra are about 30 ppm, the origin of which is mostly chemical shift dispersion, reflecting a distribution of diameter and helicity. The line width in the 13C static spectra originates from chemical shift dispersion, chemical shift anisotropy and dipole–dipole interactions between 13C spins as well as between 13C and 1H spins at defects or edges. 1H NMR spectra confirm the presence of H-containing species. The 13C spin-lattice relaxation is dominated presumably by interaction with magnetic impurities. 相似文献
102.
Masaru Hoshi Takanori Saitoh Chikako Yoshioka Akon Higuchi Tsutomu Nakagawa 《应用聚合物科学杂志》1999,74(4):983-994
The separation of a chlorinated hydrocarbon from a dilute aqueous solution through a crosslinked acrylate copolymer–porous substrate composite membrane by pervaporation was investigated. Poly(n‐butyl acrylate‐co‐acrylic acid) and poly(n‐butyl acrylate‐co‐2‐hydroxyethyl acrylate) were synthesized and composite membranes were prepared, which were made from the crosslinked polymer and a porous substrate. Pervaporation measurement was carried out for a dilute aqueous solution of 1,1,2‐trichloroethane at 25°C and under a vacuum on the permeate side (below 10 mmHg). The separation factor, overall flux, 1,1,2‐trichloroethane concentration in the membrane, and the degree of swelling decreased with increase in the acrylic acid or 2‐hydroxyethyl acrylate content of the acrylate copolymer. The influence of the crosslinking agent content on the pervaporation performance was small, and the separation factor and the overall flux showed a convex curve. The structure of the crosslinking agent had no effect on the separation. The influence of the pore size of the substrate and the thickness of the polymer layer on the separation of 1,1,2‐trichloroethane was observed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 983–994, 1999 相似文献
103.
Michio Kobayashi Yoshio Maeda Toshihiko Hoshi Jun Okubo Yoshie Tanizaki 《Coloration Technology》1989,105(10):362-368
Electronic absorption spectra of methylene blue layers adsorbed on glass plates have been measured. Higher aggregates of this dye, up to the tetramer, are shown to exist by an analysis of the aggregate spectra on the basis of a three-dimensional PPP calculation and a diagrammatic exciton-splitting model. A shoulder, located around the monomer peak, observed in the spectrum of the adsorbed methylene blue layer is tentatively assigned to the tetramer. The observed spectral behaviour on aggregation is reproduced by the PPP calculation in which a sandwich type structure is assumed for the aggregates. The band splitting patterns in the methylene blue aggregates are explained diagrammatically in terms of the interactions of the transition moments of the monomer sub-units in an aggregate. 相似文献
104.
Tetsuhiro Obana Kazuya Takahata Shinji Hamaguchi Nagato Yanagi Toshiyuki Mito Shinsaku Imagawa Kaname Kizu Katsuhiko Tsuchiya Ryo Hoshi Kiyoshi Yoshida 《Fusion Engineering and Design》2009,84(7-11):1442-1445
The superconductor test facility at the National Institute for Fusion Science (NIFS) was upgraded to test cable-in-conduit (CIC) conductors for the JT-60SA equilibrium field (EF) coil. Supercritical helium (SHe) lines were assembled with transfer tubes and a heat exchanger. The CIC conductor was covered with a thermal insulation vessel, filled with gas helium at atmospheric pressure. The temperature of the conductor was varied using a film heater attached to an inlet pipe. Critical current (Ic) and current sharing temperature (Tcs) measurements of the prototype CIC conductor were carried out successfully in the upgraded test facility. During the measurements, the conductor temperature was precisely controlled. 相似文献
105.
Motoi Tamura Chigusa Hoshi Sachiko Hori 《International journal of molecular sciences》2013,14(12):23993-24007
This study examined the effects of xylitol on mouse intestinal microbiota and urinary isoflavonoids. Xylitol is classified as a sugar alcohol and used as a food additive. The intestinal microbiota seems to play an important role in isoflavone metabolism. Xylitol feeding appears to affect the gut microbiota. We hypothesized that dietary xylitol changes intestinal microbiota and, therefore, the metabolism of isoflavonoids in mice. Male mice were randomly divided into two groups: those fed a 0.05% daidzein with 5% xylitol diet (XD group) and those fed a 0.05% daidzein-containing control diet (CD group) for 28 days. Plasma total cholesterol concentrations were significantly lower in the XD group than in the CD group (p < 0.05). Urinary amounts of equol were significantly higher in the XD group than in the CD group (p < 0.05). The fecal lipid contents (% dry weight) were significantly greater in the XD group than in the CD group (p < 0.01). The cecal microbiota differed between the two dietary groups. The occupation ratios of Bacteroides were significantly greater in the CD than in the XD group (p < 0.05). This study suggests that xylitol has the potential to affect the metabolism of daidzein by altering the metabolic activity of the intestinal microbiota and/or gut environment. Given that equol affects bone health, dietary xylitol plus isoflavonoids may exert a favorable effect on bone health. 相似文献
106.
A novel polymer blend comprising polyethylene (PE) and poly(vinyl acetate) (PVAc) with a biocompatible surface was developed for fabricating medical devices. This blend was obtained by a new synthetic method using supercritical carbon dioxide fluid. Further, the acetyl group on the surface of this blend was converted to the hydroxyl group following the phosphorylcholine (PC) group. Surface analysis of the blend with attenuated total reflection Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and dynamic contact angle measurement revealed that the PC groups were located on the surface. Biocompatibility was evaluated by the adsorption of the bovine serum albumin and bovine plasma fibrinogen on the sheet surface. The hydrophilicity of the blend depended on the surface chemical structure introduced by surface reactions. Plasma protein adsorption decreased with the surface hydrophilicity. The PC groups were highly effective in reducing protein adsorption. We conclude that our process is a promising procedure for synthesizing new polymer materials including biomaterials. 相似文献
107.
Friction damper has been found successful to prevent high frequency chatter occurring at more than 10,000Hz, and causing problem of reduced tool life in fine boring operation. The new damper is characterized by simple structure that consists of an additional mass attached to the main vibrating structure with small piece of permanent magnet. The principle is straightforward in which Coulomb and viscous frictions dissipate vibration energy at the interface between the damper and main vibrating structure. The damper needs no tuning, and is effective at high frequency. The paper first introduces a typical design of the friction damper with experimental proof by cutting tests of its effectiveness in eliminating the high frequency chatter in fine boring, and assuring normal tool life of the cutting edge. Theoretical and experimental analyses are introduced for understanding the fundamental principle and characteristics of the new damper. The new damper is effective for boring tools, which vibrate at frequency more than 5,000Hz. 相似文献
108.
A Ohkado M Hachida H Furukawa H Lu N Hanayama H Hoshi H Koyanagi 《Canadian Metallurgical Quarterly》1998,65(4):1083-1086
BACKGROUND: The number of homograft donors is limited and the once-thawed homograft may be unsuitable for the recipient and obliged to be wasted. The purpose of this study was to investigate the possibility of recryopreserving and using the once-thawed homograft for another patient. METHODS: Canine aortic valve leaflets were frozen to -80 degrees C by a programmed freezer, stored in liquid nitrogen, and thawed after 1 week. A subgroup of leaflets was left at 4 degrees C for 15 minutes, re-cryopreserved, and thawed after 1 week. Pathologic and flow cytometric evaluations were performed. RESULTS: After thawing, by pathology, alignment of the fibers was acceptably maintained but the membrane and cytoplasm of the fibroblast were damaged. These findings were not significantly aggravated even after rethawing. By flow cytometry, fibroblast viability was 90.7%+/-1.7% immediately after thawing, 87.6%+/-1.0% after thawing for 15 minutes at 4 degrees C, 63.7%+/-2.7% during refreezing at 0 degrees C, and 39.4%+/-4.3% after rethawing. CONCLUSIONS: From the standpoint of fibroblast viability, it is not possible to recryopreserve the once-cryopreserved and thawed aortic valve homograft. 相似文献
109.
H Toyama K Hoshi T Kobayashi K Hashimoto H Suzuki S Matsukawa Y Hashimoto 《Canadian Metallurgical Quarterly》1997,46(11):1503-1507
An 81-year-old man underwent percutaneous transluminal gallbladder drainage. As the drain was accidentally removed six days later, he received cholecystectomy. After the operation, he developed hypotension, hypoxemia and ST level depression on ECG. He received artificial ventilation and cathecholamines. His chest CT showed marked pulmonary edema, and total protein of the edema-fluid was 3.3 g.dl-1. These findings suggested permeability pulmonary edema. He received postural drainage of the edema-fluid, and the pulmonary oxygenation was gradually improved. He was weaned from artificial ventilation on the 6th ICU day and discharged the next day. 相似文献
110.
Keimei Oh Tadashi Matsumoto Ayumi Yamagami Tomoki Hoshi Takeshi Nakano Yuko Yoshizawa 《International journal of molecular sciences》2015,16(8):17273-17288
The plant steroid hormone brassinosteroids (BRs) are important signal mediators that regulate broad aspects of plant growth and development. With the discovery of brassinoazole (Brz), the first specific inhibitor of BR biosynthesis, several triazole-type BR biosynthesis inhibitors have been developed. In this article, we report that fenarimol (FM), a pyrimidine-type fungicide, exhibits potent inhibitory activity against BR biosynthesis. FM induces dwarfism and the open cotyledon phenotype of Arabidopsis seedlings in the dark. The IC50 value for FM to inhibit stem elongation of Arabidopsis seedlings grown in the dark was approximately 1.8 ± 0.2 μM. FM-induced dwarfism of Arabidopsis seedlings could be restored by brassinolide (BL) but not by gibberellin (GA). Assessment of the target site of FM in BR biosynthesis by feeding BR biosynthesis intermediates indicated that FM interferes with the side chain hydroxylation of BR biosynthesis from campestanol to teasterone. Determination of the binding affinity of FM to purified recombinant CYP90D1 indicated that FM induced a typical type II binding spectrum with a Kd value of approximately 0.79 μM. Quantitative real-time PCR analysis of the expression level of the BR responsive gene in Arabidopsis seedlings indicated that FM induces the BR deficiency in Arabidopsis. 相似文献