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AgGaTe2 and AgAlTe2 layers were grown on a-plane sapphire substrates by closed-space sublimation. These compounds replace Cd in CdTe with group I and III elements, and are, hence, expected to be ideal novel candidate materials for solar cells. The grown layers were confirmed to be stoichiometric AgGaTe2 and AgAlTe2 by x-ray diffraction (XRD). The AgAlTe2 layers had strong preference for the (112) orientation. The XRD spectrum of the AgGaTe2 layer was different from that of the AgAlTe2 layer, and strong peaks were observed for (103) and (110) diffraction. The variation in orientations of the grown layers was analyzed in detail by use of XRD pole figures, which revealed that the AgGaTe2 layers had an epitaxial relationship with the a-plane sapphire substrates. 相似文献
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Masahiko Okumura Ayaka Ikado Yasuhiro Saito Hideyuki Aoki Takatoshi Miura Yoshiaki Kawakami 《International Journal of Hydrogen Energy》2012
In-situ and transient visualizations of the packing structure of a hydrogen storage alloy bed are carried out using an X-ray computed tomography (CT) system. The packing structure is clearly observed on the microscale using the CT system. When the alloy bed is subjected to hydrogen absorption–desorption cycles, the pulverization progresses from the lower to the upper regions of the bed. After several hydrogen absorption–desorption cycles, the packing structure in the lower region of the bed changes and the microstructural void decreases slightly. Based on these results, we propose a pulverization mechanism of the packed bed in which the friction between particles affects the pulverization process. 相似文献
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Chikara Tsutsumi Ryouji Watanabe Ayaka Tokumaru Nao Kuwaoka Yuushou Nakayama Takeshi Shiono 《应用聚合物科学杂志》2016,133(39)
Synthetic l ‐lactide random copolymers can be employed as controlled release materials when prepared using supercritical carbon dioxide (scCO2), since they are biodegradable via hydrolysis. To determine the effects of thermal properties on polymer performance following scCO2 processing, three types of poly(l ‐lactide) having different properties were assessed. The Tm of one poly(l ‐lactide) sample (H‐100) was found to be approximately 170 °C over the processing pressure range from 8 to 18 MPa, while a second sample (H‐440) also showed a constant value of approximately 152 °C. In contrast, the poly(l ‐lactide) REVODE exhibited a Tm of 146 °C prior to processing but a higher value of 147 °C following treatment at 8 MPa. Unlike the H‐100 and H‐440, the Tm value of the REVODE tended to decrease with increasing pressure. The Tg values increased greatly under mild conditions of 8 MPa pressure and a temperature of 40 °C. In particular, the Tg values for the H‐440 and REVODE increased by 4 °C and 5 °C, respectively. All Tg values were lowest at 12 MPa and increased with increasing processing pressure, although the effect of processing temperature was minimal. The Χc DSC of the H‐100 was 18% initially but increased to 20% upon scCO2 processing at 40 °C and 14 MPa, and showed further increases at higher processing temperatures. Although the relationship between processing temperature and Χc DSC values for the H‐440 showed the same trend as observed with the H‐100, a different trend was seen for the REVODE. The Χc XRD values obtained from the XRD analyses differed from the values generated by DSC analysis, and showed a maximum degree of crystallinity following processing at 80 °C both with and without scCO2 treatment. ATR FT‐IR analyses identified peaks due to semicrystalline regions in poly(l ‐lactide) samples treated with scCO2, even when applying low temperatures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44006. 相似文献
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Keiichi Miyamoto Ayaka Kawasaki Yuko Nagata Masanori Uraya Hisayoshi Kojima Takanori Ito Takashi Horiuchi Nagisa Asakawa Shinsuke Nomura 《Materials science & engineering. C, Materials for biological applications》2011,31(2):158-165
Immunoglobulin A1 (IgA1) concentration in the plasma of patients with IgA nephropathy (IgAN) as the cause of renal failure is higher than that in the plasma of normal controls. IgA1 with abnormal sugars is considered to deposit in the glomerular mesangium, aggravating nephritis in IgAN. Jacalin is a lectin that recognizes sugars on IgA1. However, its selective-recognition for normal-type (ST type, NeuAc-α(2,3)-Gal-β(1,3)-GalNAc) and abnormal-type (T type, Gal-β(1,3)-GalNAc; Tn type, GalNAc; STn type, NeuAc-α(2,6)-GalNAc) sugars α-O-linked to serine/threonine in IgA1 is weak. Therefore, jacalin cannot be used for recognizing specific sugar types on IgA1. We attempted to develop a new recognition method for specific sugar types on IgA1 by utilizing the multirecognition capability of jacalin. Its binding abilities were regulated by heat denaturation with suitable template sugar (galactose or N-acetylgalactosamine). Further, we successfully prepared denatured-jacalin derivatives, which recognized ST-/T-type sugars on IgA1, by sugar-immobilized affinity chromatography. Enzyme-linked immunosorbent assay of denatured-jacalin derivatives, showed the ratios of abnormal sugars on IgA1 in the plasma of IgAN patients and normal controls to be approximately 60% and 20%, respectively. The results proved that profiling of sugar types in IgAN can successfully be performed by solely using jacalin derivatives. 相似文献
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Shuichi Nakamura Ayaka Toda Masahide Sano Tsubasa Hatanaka Yasuhiro Funahashi 《Advanced Synthesis \u0026amp; Catalysis》2016,358(7):1029-1034
We disclose herein an efficient enantioselective conjugate addition reaction between coumarin‐3‐carboxylic acids and malonic acid half thioesters (MAHTs). The reaction was catalyzed by N‐heteroarenesulfonyl Cinchona alkaloid amides to afford double‐decarboxylative conjugate addition products in good yield with high enantioselectivity. The reaction of various coumarin‐3‐carboxylic acids with MAHTs gave products in high yield with high enantioselectivity.
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Hidemasa Hikawa Ayaka Tada Shoko Kikkawa Isao Azumaya 《Advanced Synthesis \u0026amp; Catalysis》2016,358(3):395-402
We demonstrate the gold(III)‐catalyzed direct substitution of benzylic alcohols in water. These atom economic and environmentally benign protocols afford S‐benzylated products in moderate to excellent yields. In contrast, common Lewis or Brønsted acids as catalyst, and organic solvents such as dichloromethane or toluene were ineffective for the S‐benzylation of mercaptobenzoic acids. Water can be an attractive tool for new transition metal‐catalyzed reactions. A Hammett study for the rate constants with various substituted alcohols shows a good correlation (R2=0.97) between the log(kX/kH) and the σ+ value of the respective substituents. From the slope negative ρ values of 2.35 are obtained, suggesting that there is a build‐up of positive charge in the transition state. Our catalytic system can be performed with the use of only 2 mol% of gold(III) catalyst without any other additives in water, and scaled up to 10 mmol scale (85% isolated yield). Notably, the present method can accomplish the S‐benzylation of unprotected mercaptobenzoic acids, which is chemoselective and leaves the carboxyl group intact. Furthermore, the direct substitution of allylic and propargylic alcohols also proceeded smoothly in good yields.
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Michio Yamada Konomi Tokutomi Ayaka Takehara Yusuke Sakai Yutaka Maeda Tadashi Hasegawa 《Fullerenes, Nanotubes and Carbon Nanostructures》2014,22(1-3):66-74
Tröger's base (TB, 1) and its analogues were synthesized and were subject to the titration experiments to evaluate their ability of supramolecular complexation with C60. Results demonstrate clearly that the fluorene-based TB analogue (2) and the bioctylfluorene-based TB analogue (3) show 1:1 binding with C60 to form the corresponding complexes while TB 1 does not. Titration experiments exhibited that the association constant (Kass) of 3/C60 (48.1 ± 7.9 M ?1) was larger than that of 2/C60 (13.7 ± 1.4 M ?1). The formation of the 1:1 binding complexes 2/C60 and 3/C60 was also confirmed by MALDI-TOF mass spectrometry. Theoretical calculations suggest that 2 and 3 have appropriate cavities to embrace C60. These findings indicate that not only the π/π interaction between the fluorene moieties and the C60 surface but also the CH/π interaction between the octyl groups and the C60 surface serve efficiently in the supramolecular complexation with C60. 相似文献