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291.
Hiromitsu Kozuka Shinsuke Takenaka Hiroshi Tokita Toshihiro Hirano Yugo Higashi Takao Hamatani 《Journal of Sol-Gel Science and Technology》2003,26(1-3):681-686
Residual stress was evaluated by measuring the substrate curvature for alkoxide-derived silica and titania films deposited on silica glass substrates. The residual stress was tensile, increasing with increasing heat-treatment temperature. The stress in fired films was affected greatly by water/alkoxide ratio and chelating agents in starting solutions. Secondly, in situ observation was made on cracking of gel films subjected to heat-treatment. Silica and titania gel films deposited on silicon wafers were cracked in the heating-up stage at temperatures of 100°–400°C, depending on the film thickness and heating rate. Larger thickness and lower heating rates were found to lower the cracking onset temperature. Finally, organic polymers with amide groups were demonstrated to increase the uncracking critical thickness. The polymers include polyvinylpyrrolidone and polyvinylacetamide, allowing single layer ceramic coating films over 1 m in thickness to be formed without cracking. 相似文献
292.
293.
Kishimoto Mizuki Izawa Hironori Saimoto Hiroyuki Ifuku Shinsuke 《Cellulose (London, England)》2022,29(5):2829-2837
Cellulose - Blue, red and yellow chitin nanofibers were obtained using reactive dyes. Since the chitin nanofibers and the dye are covalently bonded, they are resistant to hot water and detergents.... 相似文献
294.
An exhaustive analysis of metabolites in hair samples has been performed for the first time using ultra performance liquid chromatography with electrospray ionization time-of-flight mass spectrometry (UPLC-ESI-TOF-MS). The hair samples were collected from spontaneously hypertensive model rats (SHR/Izm), stroke-prone SHR (SHRSP/Izm) and Wistar Kyoto (WKY/Izm) rats, and were analyzed by UPLC-ESI-TOF-MS; a multivariate statistical analysis method, such as the principal component analysis (PCA), was then used for screening the biomarkers. From the samples derived from the group of SHRSP/Izm at weeks 10, 18, 26 and 34, we successfully detected a potential biomarker of stroke, which existed at much higher concentrations as compared with that in the other groups. However, a significant difference could not be found at weeks less than 7 before the rats were subjected to stroke and hypertension. In addition, the present method was applicable to screening not only the disease markers, but also the markers related to aging. The method utilizing hair samples is expected to be quite useful for screening biomarkers of many other diseases, and not limited to stroke and hypertension. 相似文献
295.
The [3 + 2 + 2] cocyclization of ethyl cyclopropylideneacetate (1a) and various alkynes proceeded smoothly in the presence of Ni(cod)2-PPh3. The cycloheptadiene derivatives were synthesized in highly selective manners. The unique reactivity of 1a was essential for the progress of the reaction. The observed regioselectivity of the product formation and the mechanism of the reaction are discussed. 相似文献
296.
297.
Although organotins are notorious man-made organometallic species introduced into the aquatic environment, no investigation had been concerned with contamination of higher trophic animals such as marine mammals until the last few years. Our recent work demonstrated the detection of butyltin compounds (BTCs), including mono- (MBT), di-(DBT), and tri-butyltin (TBT) in marine mammals. This paper reviews BTC contamination in higher trophic animals, based on our recent publications. Analysis for BTCs showed significant accumulation in tissues and organs of three finless porpoises ( Neophocaena phocaenoides ) collected from Japanese coastal waters. More than 10 μg of butyltin ions per gram on a wet weight basis were detected in the liver of a porpoise collected in the semi-closed sea. Distribution of BTCs in the tissues and organs of the porpoises showed a similar pattern to several other marine mammal species: higher concentrations in liver and kidney, and lower in muscle and blubber. In addition, tissues and organs from two water birds and one sea turtle species were also analyzed for BTCs, and their concentrations and compositions were compared among the species. The results showed that the distribution of these contaminants extends widely, not only to marine mammals but also to other higher trophic species. On the other hand, the composition of the BTCs exhibited a specific profile in each species. The ratios of hepatic concentrations of DBT or MBT to TBT for marine mammals were relatively lower than those of water birds and the sea turtle, indicating that metabolism and excretion of TBT may be less efficient in the mammalian species. © 1997 by John Wiley & Sons, Ltd. 相似文献
298.
Let G be a graph of order n, and n = Σki=1 ai be a partition of n with ai ≥ 2. In this article we show that if the minimum degree of G is at least 3k−2, then for any distinct k vertices v1,…, vk of G, the vertex set V(G) can be decomposed into k disjoint subsets A1,…, Ak so that |Ai| = ai,viisAi is an element of Ai and “the subgraph induced by Ai contains no isolated vertices” for all i, 1 ≥ i ≥ k. Here, the bound on the minimum degree is sharp. © 1997 John Wiley & Sons, Inc. 相似文献
299.
Masaru Kitagawa Shinsuke Takegami Yutaka Tokiwa 《Macromolecular rapid communications》1998,19(3):155-158
To develop a new synthetic polymer containing sugar branches, radical polymerization of the reducing vinyl sugar ester 6-O-vinyladipoyl-D -glucose ( 1 ) was performed in an organic solvent or in water. The polymers obtained with several azoinitiators in dimethylformamide (DMF) showed comparatively low average molecular weight (M̄n ≈ 4500). In contrast, the use of a redox initiator (FeSO4 and H2O2) in water gave polymers of higher average molecular weight (M̄n ≈ 33000) in higher yield (90%), followed by crosslinking at high conversions. 相似文献
300.
Kuno Takuma Nakamura Toshiteru Matsuda Takahiro Onoe Shinsuke Seo Yoshiho Ouchi Satoshi 《Optical Review》2021,28(6):716-722
Optical Review - For ultra-compact near-eye display, waveguides provide a small form factor because they are thin shape plate, but projectors are too large due to the imaging sources, which results... 相似文献