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排序方式: 共有1164条查询结果,搜索用时 15 毫秒
91.
Kyung-Cho Kim Hiroaki Fukubara Hisashi Yamawaki Tetsuya Saito 《Journal of Mechanical Science and Technology》2001,15(1):52-60
In this paper, as a new measurement method to estimate the change of material condition, the simplified ultrasonic CT system,
which uses the information of three directions, that is, 90°, + 45° and −45° about inspection plane is proposed. Use of simplified
CT system has two merits: Firstly, the measurement time is very short compared with general CT. Secondly, it can detect sensitively
small defect in vertical or slant direction about inspection plane because the obtained image is CT image calculated from
three directions. From these merits, this method can be considered as an effective method to evaluate material conditions.
The basic performance of the proposed method was confirmed through several specimens with several simple defects. In order
to confirm the applicability of actual NDT, several kinds of welded specimens are investigated. The result showed that the
CT image obtained had good agreement with actual defect of specimens. 相似文献
92.
93.
Glow-discharge-hydrogenated amorphous silicon (a-Si : H) was found to be oxidized in the following two ways after exposing to air at room temperature; first, thin oxide films grew uniformly on the a-Si : H, slowly with increase of exposure time; secondly, oxide with a columnar morphology grew rapidly with the increase of exposure time and the cross section of the columnar oxide was small. Mechanical stress caused by the differences of the thermal expansion coefficient and the crystallographical structure between the a-Si : H and substrates was relieved with the increase in the amount of the columnar oxide. 相似文献
94.
Gabsoo Do Tetsuya Araki Yeonghwan Bae Ko Ishikura Yasuyuki Sagara 《Drying Technology》2015,33(13):1614-1620
A novel technique was developed to recognize ice crystals in biological materials and to analyze their three-dimensional morphology using a Cryogenic Micro-Slicer Spectral Imaging System with a micro-slicer unit and a near-infrared spectral imaging unit. Consecutive cross-sections of a frozen sample were exposed by the multi-slicing operations with a minimum thickness of 1 µm, and their images were taken by the imaging unit. Spectroscopic analysis using a near-infrared spectrum meter showed an absorption peak at 1460 nm for pure water. Based on the observations of the absorption band of ice crystals in the wavelength range of 1450–1570 nm and its peak at 1495 nm, a commodity-type bandpass filter with a central wavelength of 1500 nm was adopted to identify ice crystals in near-infrared images. The absorption peak of water exhibited a tendency to move toward longer wavelengths with decreasing sample temperature from 25 °C to ?15 °C. The filtered images of ice crystals in frozen samples were darker than the other components at the peak wavelength of ice crystals. The three-dimensional reconstructed morphology of ice crystals revealed that they were formed along the direction of heat transfer while freezing. The proposed method provides a novel tool to investigate the effects of freezing conditions on the size, morphology and distribution of ice crystals. 相似文献
95.
Liposome‐Based in Vitro Evolution of Aminoacyl‐tRNA Synthetase for Enhanced Pyrrolysine Derivative Incorporation 下载免费PDF全文
Dr. Atsuko Uyeda Dr. Takayoshi Watanabe Dr. Yasuhiko Kato Prof. Hajime Watanabe Prof. Tetsuya Yomo Prof. Takahiro Hohsaka Dr. Tomoaki Matsuura 《Chembiochem : a European journal of chemical biology》2015,16(12):1797-1802
Methanosarcina species pyrrolysyl‐tRNA synthetase (PylRS) attaches Pyl to its cognate amber suppressor tRNA. The introduction of two mutations (Y384F and Y306A) into PylRS was previously shown to generate a mutant, designated LysZ‐RS, that was able to attach N‐benzyloxycarbonyl‐L ‐lysine (LysZ) to its cognate tRNA. Despite the potential of LysZ derivatives, further LysZ‐RS engineering has not been performed; consequently, we aimed to generate LysZ‐RS mutants with improved LysZ incorporation activity through in vitro directed evolution. Using a liposome‐based in vitro compartmentalization (IVC) approach, we screened a randomly mutagenized gene library of LysZ‐RS and obtained a mutant that showed increased LysZ incorporation activity both in vitro and in vivo. The ease and high flexibility of liposome‐based IVC should enable the evolution of not only LysZ‐RS that can attach various LysZ derivatives but also of other enzymes involved in protein translation. 相似文献
96.
Hamidreza Esmaielpour Vincent R. Whiteside Jinfeng Tang Sangeetha Vijeyaragunathan Tetsuya D. Mishima Shayne Cairns Michael B. Santos Bin Wang Ian R. Sellers 《Progress in Photovoltaics: Research and Applications》2016,24(5):591-599
InAs/AlAsxSb1 − x quantum wells are investigated for their potential as hot carrier solar cells. Continuous wave power and temperature‐dependent photoluminescence indicate a transition in the dominant hot carrier relaxation process from conventional phonon‐mediated carrier relaxation below 90 K to a regime where inhibited radiative recombination dominates the hot carrier relaxation at elevated temperatures. At temperatures below 90 K, photoluminescence measurements are consistent with type‐I quantum wells that exhibit hole localization associated with alloy/interface fluctuations. At elevated temperatures, hole delocalization reveals the true type‐II band alignment, where it is observed that inhibited radiative recombination due to the spatial separation of the charge carriers dominates hot carrier relaxation. This decoupling of phonon‐mediated relaxation results in robust hot carriers at higher temperatures, even at lower excitation powers. These results indicate type‐II quantum wells offer potential as practical hot carrier systems. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
97.
A new synthesis route for elastic polyurethane‐imides (EPUIs) has been established by a method involving the use of urea. Various EPUIs were synthesized from polyurethane‐urea, which was prepared from 4,4′‐diphenylmethane diisocyanate (MDI), polyoxytetramethylene glycol (PTMG) and 4,4′‐diphenylmethanediamine (MDA), and pyromellitic dianhydride in N‐methyl‐2‐pyrrolidone (NMP). Flexible films were cast from these solutions that had different inherent viscosities. Imidization of the EPUI films was completed at 200°C for 4 h in vacuo. The EPUIs were determined by FTIR, 1H NMR, and 13C NMR spectra. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
98.
Daisuke Kosemura Maki Hattori Tetsuya Yoshida Toshikazu Mizukoshi Atsushi Ogura 《Journal of Electronic Materials》2010,39(6):694-699
Defects and stress gradually accumulate throughout various Si large-scale integration fabrication processes. It is essential
to monitor defects and stress carefully to suppress their unintentional introduction. In this study, we measured the stress
and crystal quality in shallow trench isolation (STI) samples by ultraviolet (UV)-Raman spectroscopy with an extremely high-resolution
wavenumber to evaluate the effect of post-annealing on the recovery of Si crystals. The variations of crystal quality in 200-mm
wafers with STI structures gradually decreased after post-annealing for 4 h, 6 h, and 8 h; however, there was no substantial
difference in the values of full-width at half-maximum of the Raman spectra. Precise measurements of variations of stress
and crystal quality were successfully performed by UV-Raman spectroscopy with a high-resolution wavenumber, which enabled
us to evaluate the STI process accurately. 相似文献
99.
100.
Tetsuya Shishido Tomoyuki Kitano Kentaro Teramura Tsunehiro Tanaka 《Topics in Catalysis》2010,53(7-10):672-677
Nb2O5/Al2O3 catalysts calcined at high temperatures exhibited the Brønsted acid property. A monolayer of niobic acid-like compound, which has distorted octahedral symmetry, was stabilized over 16 wt% Nb2O5/Al2O3 catalyst calcined at 1,173 K. The two-dimensional Nb–O–Nb network of stabilized niobic acid-like compound probably accounts for the generation of Brønsted acid. 相似文献