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991.
Noriyuki Hara Shuichi Nakamura Yasuhiro Funahashi Norio Shibata 《Advanced Synthesis \u0026amp; Catalysis》2011,353(16):2976-2980
The organocatalytic enantioselective decarboxylative addition of malonic acids half thioesters to isatins using a squaramide catalyst afforded the products with high enantioselectivity. These products are key intermediates in the synthesis of 3‐substituted 3‐hydroxy‐2‐oxindole derivatives. The first enantioselective synthesis of (−)‐flustraminol B has been accomplished. 相似文献
992.
Jyomoto T Azuma M Islam NN Fujinami R Takao T Ogawa T Tabuchi M Igarashi K Kato J Ooshima H 《Journal of Bioscience and Bioengineering》2006,102(3):193-197
The enzyme that catalyzes N-acyl linkage between myristic acid and the NH(2)-terminal glycine residue of the octapeptide Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg-NH(2) in aqueous solution without ATP and coenzyme A was found in Pseudomonas aeruginosa. The enzyme was purified from cell-free crude extract using DEAE-Cellulose, Sephadex G-200, CM-Sephadex C-50, and hydroxyapatite column chromatographies, and then purified approximately 1900-fold with about 1.5% recovery of enzyme activity from the crude extract. Finally, the purified enzyme showed a main band on SDS polyacrylamide gel electrophoresis after staining with Coomassie Brilliant Blue. The band corresponded to a molecular mass of approximately 60 kDa. The K(m)s of the purified enzyme for the substrate myristic acid and the octapeptide were 0.36 and 2.6 mM, respectively. When myristoyl-CoA instead of myristic acid was used as the substrate for the enzyme reaction, myristoyl octapeptide could be synthesized as observed in the case of myristic acid. The K(m) of myristoyl-CoA was 0.17 mM. 相似文献
993.
We present experimental results verifying the optical robustness of a 1 x 1 multimode interference (MMI) device that is directly butt coupled with optical fibers at 70 degrees C for 1050 h and discuss the gradual increase of polarization dependent loss. Based on this structure, an electro-optic (EO) MMI waveguide device that can control the output optical power by using an electrode structure located directly on top of the multimode is presented. As a proof of principle, we demonstrate the switching operation of the EO-MMI device using commercially available chromophore as the active EO material. 相似文献
994.
Mitamura K Imae T Mouri E Torikai N Matsuoka H Nakamura T 《Journal of nanoscience and nanotechnology》2006,6(1):36-42
Hybrid Langmuir and Langmuir-Blodgett monolayers of a perfluorooctadecanoic acid mixed with a rigid block copolymer, poly(3,5-bis(3,5-bis(benzyloxy)benzyloxy)benzyl methacrylate-randommethacrylic acid)-block-poly(2-perfluorooctylethyl acrylate), which is composed of benzyloxy dendron side chains and perfluorinated side chains, were prepared and characterized by surface pressure-surface area isotherms, atomic force microscopic images and neutron and X-ray reflectometries. The two-dimensionally phase-separated structures of monolayer films and their morphologies with plateau and terrace were confirmed. The monolayers were separated into a dendron layer, a perfluorinated layer, and a carboxyl layer. The layer formation is originated not only in the intermolecular interaction between a perfluorooctadecanoic acid and a block copolymer but also in the geometry of the molecules. Especially, the amphiphilicity of perfluorinated surfactant plays a role to the ordered array of the block copolymers. 相似文献
995.
Yamada A Koizumi H Nishimura S Sonoyama N Kanno R Yonemura M Nakamura T Kobayashi Y 《Nature materials》2006,5(5):357-360
The rechargeable lithium-ion cell is an advanced energy-storage system. However, high cost, safety hazards, and chemical instability prohibit its use in large-scale applications. An alternative cathode material, LiFePO(4), solves these problems, but has a kinetic problem involving strong electron/hole localization. One reason for this is believed to be the limited carrier density in the fixed monovalent Fe(3+)PO(4)/LiFe(2+)PO(4) two-phase electrode reaction in LixFePO4. Here, we provide experimental evidence that LixFePO4, at room temperature, can be described as a mixture of the Fe(3+)/Fe(2+) mixed-valent intermediate LialphaFePO4 and Li1-betaFePO4 phases. Using powder neutron diffraction, the site occupancy numbers for lithium in each phase were refined to be alpha=0.05 and 1-beta=0.89. The corresponding solid solution ranges outside the miscibility gap (0相似文献
996.
Katsuhiro Narasaki Shoji Tsunematsu Kiyomi Ootsuka Kenichi Kanao Akinobu Okabayashi Kazuhisa Mitsuda Hiroshi Murakami Takao Nakagawa Kenichi Kikuchi Ryota Sato Hiroyuki Sugita Youichi Sato Masahide Murakami Masanori Kobayashi 《低温学》2012,52(4-6):188-195
This report describes the results and operating status of ground lifetime testing and achievements on orbit of coolers for space use. Ground lifetime tests of coolers of three types were conducted to demonstrate their long life and reliability. Three single-stage Stirling coolers were tested for 89,016, 71,871 and 68,273 h from 1998, a two-stage Stirling cooler was tested for 72,906 h, and a 4-K class cooler with a two-stage Stirling cooler and a Joule–Thomson cooler was tested for over 2.5 years. After lifetime tests were completed, a few coolers were investigated to determine the cause of the cooling performance degradation. Additionally, the filled gas of the coolers was analyzed. These coolers have shown good results on orbit. Three single-stage Stirling coolers were carried on the X-ray astronomical satellite “SUZAKU” (launched in July 2005), Japanese lunar polar orbiter “KAGUYA” (launched in September 2007), and the Japanese Venus Climate Orbiter “AKATSUKI” (launched in June 2010). Two units of a two-stage Stirling cooler were carried on the infrared astronomical satellite “AKARI” launched in February 2006. A 4-K class cooler was carried on the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) aboard the Japanese Experiment Module (JEM) of the International Space Station (ISS). SMILES was launched in September 2009. 相似文献
997.
Nobuyuki?ShirakawaEmail author Takao?Furukawa Minoru?Nomura Kumi?Okuwada 《Scientometrics》2012,91(3):895-910
This study analysed the technical and publication activities of the Institute of Electrical and Electronics Engineering (IEEE),
the most influential academic publisher in engineering. We first constructed an original comprehensive database of periodicals
(journal and magazine) and conference proceedings published by the IEEE between 1980 and 2008, which comprised approximately
0.36 million periodical articles and 1.14 million conference articles. We analysed the transitions in technical innovations
from two perspectives: trends within (1) individual countries and (2) specialized fields represented in IEEE societies. The
number of published periodical articles increased fourfold between 1980 and 2008, while that of published conference articles
increased nearly 20-fold in the same period. In particular, the number of conference articles published by China increased
dramatically from 2002, exceeding even the number published by the US in 2008. The IEEE has increasingly shifted away from
its US-centred origins to literally becoming the ‘electrical and electronics association of the world’. The proportion of
articles published by authors in North America, Europe and East Asia has increasingly balanced, thus leading to the formation
of a tri-polar structure of IEEE technological activities. This comprehensive analysis of IEEE publications over a period
of almost 30 years revealed that with the emergence of more active international competition, ‘glocalisation’ is occurring
among publications and research activities of the IEEE. Consequently, quantitative analysis revealed structural changes in
global competition and technological transition characterized by five phases. 相似文献
998.
A lithium-encapsulated fullerenol Li@C60(OH)18, as an example of a polar solvent-soluble endohedral fullerene derivative, has been synthesized and fully characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, UV spectroscopy, electron spin resonance (ESR) spectroscopy, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), elemental analysis, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the particle size was determined using the induced grating (IG) method, and scanning probe microscopy. The encapsulated Li+ was clearly detected by 7Li NMR at very high field in the range −15 to −19 ppm, an intermediate lithium-encapsulated fullerenol was detected by MALDI-TOF-MS, and the molar ratio of lithium-encapsulated fullerenol to empty fullerenol was quantitatively determined to be 12:88 by ICP-AES. The solid-state ESR and particle size measurements using the IG method showed the characteristic anionic behavior with no external counter cations, in what can be called a “cation-encapsulated anion nanoparticle”, revealing the drastic differences between its properties and those of empty C60(OH)16. 相似文献
999.
Xiuzhong Shen Ryota Matsui Kaichiro Mishima Hideo Nakamura 《Nuclear Engineering and Design》2010,240(12):3991-4000
In view of practical importance of the drift flux model for two-phase flow analysis in general, and in the analysis of nuclear reactor transients and accidents in particular, the distribution parameter, and the drift velocity have been studied for two-phase flow in a vertical large diameter pipe. In this, study, local measurements were performed on flow parameters, such as void fraction, gas velocity and, liquid velocity in a vertical upward air–water two-phase flow in a pipe of 200 mm inner diameter and, 25 m in height by using the local sensor techniques such as hot-film probes, optical multi-sensor, probes and differential pressure gauges. Two-phase flow regimes in a vertical large diameter pipe, were classified into bubbly, churn and slug flows according to the visual observation. The values of the, distribution parameter and the mean drift velocity were determined directly by their definition using experiment data of the local flow parameters in a two-phase flow in a large diameter pipe. Various existing drift flux correlations were compared with the present experimental results and experimental data obtained by other researchers. A detailed discussion on the problems of these correlations was presented in this paper. 相似文献
1000.
Nigel Jollands Paul Waide Mark Ellis Takao Onoda Jens Laustsen Kanako Tanaka Philippine de T’Serclaes Ingrid Barnsley Rick Bradley Alan Meier 《Energy Policy》2010
The imperative to pursue energy efficiency improvements is clearly on the political agenda at all levels of governments. This paper explores the lessons from past attempts at galvanising international efforts to expand energy efficiency activities through the use of international-level recommendations. Drawing on these lessons, the paper outlines the IEA response to the call for policy advice on energy efficiency through the G8 Gleneagles Plan of Action. Specifically, the paper outlines a ‘necessary conditions’ framework that was used to develop a set of energy efficiency policy priorities and describes the subsequent recommendations presented to the G8 in Hokkaido–Toyako Summit in 2008. The recommendations cover 25 fields of action in seven priority areas: buildings, appliances, lighting, transport, industry, energy utilities and cross-sectoral issues. Together, the suite of recommendations sets out an ambitious road map for global energy efficiency improvement. If implemented globally without delay, they could save around 8.2 GtCO2/yr or 96 EJ/yr by 2030. This is equivalent to roughly twice the current total EU energy-related CO2 emissions. 相似文献