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31.
Noboru Yoshikawa Guoqiang XieZiping Cao Dmitri V. Louzguine 《Journal of the European Ceramic Society》2012,32(2):419-424
An Fe3O4 powder compact was irradiated with a 2.45 GHz microwave single-mode applicator at the magnetic field maximum position. Selectively heated regions (hot spot region) having several hundred micrometers to millimeter scale were formed. They exhibited metallic color. The SEM/EDX observations showed no appreciable difference in the compositions between the hot spot regions and the matrix. However, micro-XRD revealed that the hot spot region had a larger fraction of FeO than the matrix did, although the major consisting phase was Fe3O4 with a little Fe2O3. TEM observations indicated that the observed hot spot regions comprise these oxide phases separated in nano-sized grains, which agrees with our previous report. The larger fraction of FeO phase and flat surface might be related with the metallic color of the hot spot region. Their formation mechanisms and phase constitution were discussed. 相似文献
32.
本文建立了新的卧式振动沸腾床旧砂冷却系统的数学模型,并进行了计算机数字模拟。通过模拟,研究了几个工艺参数对旧砂冷却的影响,并应用能耗指数E和冷却效率η对工厂中使用的旧砂冷却装置进行了评价。 相似文献
33.
Nguyen Chi Trung Ngo Hironari Sugiyama Buddhika Amila Kumara Sodige Juan Paulo Wiff Satoru Yamanaka Yoonho Kim Tsuneo Suzuki Masaaki Baba Masatoshi Takeda Noboru Yamada Koichi Niihara Tadachika Nakayama 《Journal of the American Ceramic Society》2023,106(1):201-212
The energy-harvesting ability of the lead-free ferroelectric Ba(Zr,Ti)O3 was investigated and greatly enhanced using the Kim novel electrothermodynamic cycle for low-temperature application. Ba(Zr,Ti)O3 was synthesized with a Zr:Ti ratio of 10:90 (BZT10) by hot-press sintering, which exhibited a mix relaxor-ferroelectric behavior. For power generation using the Kim cycle with low and high temperatures of TL = 25°C, TH = 120°C, the most optimized temperature pattern occurred for a heating time of 12.5 s and a cooling time of 22.5 s. Under these conditions, the electric field increased during the novel isodisplacement process, and the displacement variation in the isoelectric step reached the highest value and maximized the BZT10 cycle loop area. Applying these conditions while lowering TL to 20°C, an energy density ND = 504 mJ/cm3 was achieved. This value is the highest obtained energy density in a practical test for lead-free ferroelectric bulk material in the BaTiO3 family. 相似文献
34.
Shoji Iwabuchi Prof. Dr. Shin-ichiro M. Nomura Prof. Dr. Yusuke Sato 《Chembiochem : a European journal of chemical biology》2023,24(4):e202200568
Purification of functional DNA nanostructures is an essential step in achieving intended functions because misfolded structures and the remaining free DNA strands in a solution can interact and affect their behavior. However, due to hydrophobicity-mediated aggregation, it is difficult to purify DNA nanostructures modified with hydrophobic molecules by conventional methods. Herein, we report the purification of cholesterol-modified DNA nanostructures by using a novel surfactant-assisted gel extraction. The addition of sodium cholate (SC) to the sample solution before structure folding prevented aggregation; this was confirmed by gel electrophoresis. We also found that adding sodium dodecyl sulfate (SDS) to the sample inhibited structural folding. The cholesterol-modified DNA nanostructures prepared with SC were successfully purified by gel extraction, and their ability to bind to the lipid membrane surfaces was maintained. This method will facilitate the purification of DNA nanostructures modified with hydrophobic molecules and expand their applicability in the construction of artificial cell-like systems. 相似文献
35.
Strain-induced ordering of microdomain structures in cross-linked polystyrene-block-polybutadiene-block-polystyrene (SBS) triblock copolymers was examined by the small-angle X-ray scattering technique. To stretch the SBS samples at elevated temperature above the glass transition temperature of polystyrene, polybutadiene blocks were chemically cross-linked in the disordered state. The initial morphology was disorder-like or bicontinuous due to incompletion of microphase separation in the presence of the chemical cross-links. When the cross-linked SBS samples were mechanically stretched at 130 °C and were further annealed for 24 h under a stretched state, the random domain structures ordered gradually and lamellar-like regularity was finally attained. It was found that the ordering proceeded more for the case of the higher strain. 相似文献
36.
Takashi Hayakawa Hideo Orita Masao Shimizu Katsuomi Takehira Arnfinn G. Andersen Kiyoshi Nomura Yusuke Ujihira 《Catalysis Letters》1992,16(4):359-371
The catalytic activity of LaCoO3–-based mixed oxides for the oxidative coupling of methane has been tested by TPR and cyclic reaction. Characterization has been done by XRD, TGA and Mössbauer spectrometry. It is likely that the perovskite-crystal structure containing hypervalent metal ions has an important role and that unique structural oxygen species in the perovskite contribute to the partial oxidation of methane. 相似文献
37.
Hidetaka Yoshikawa Katsuya Fukuyama Yoichiro Nakahara Takehisa Konishi Nobuyuki Ichikuni Yasuko Yoshikawa Noboru Akuzawa Yoichi Takahashi Keiko Nishikawa 《Carbon》2003,41(15):2931-2938
The structure of bromine residue compounds was investigated by X-ray absorption fine structure (XAFS) in order to interpret where and how bromine is present in carbons with different degrees of graphitization. The residue compounds can be classified into three groups, as obtained from X-ray absorption near edge structure (XANES) spectra and the values of the intramolecular distance rBr–Br determined by extended X-ray absorption fine structure (EXAFS). In Group I, prepared from the host carbons heat treated at temperatures higher than 1900 °C, bromine exists in the interlayer space of graphite in the form of Br2 molecules with interaction of the π electrons of graphite. In Group III, from carbon heat treated at 1000 °C, most of the bromine probably reacts with carbon atoms having a dangling bond or functional groups. For Group II, where the host carbons are heat treated at intermediate temperatures, it is likely that bromine exists in undeveloped defects with a unique electronic state. 相似文献
38.
Nomura SM Tsumoto K Hamada T Akiyoshi K Nakatani Y Yoshikawa K 《Chembiochem : a European journal of chemical biology》2003,4(11):1172-1175
Functional protein synthesis was observed in cell-sized lipid vesicles following encapsulation of a gene-expression system. Expression of rsGFP (red-shifted green fluorescent protein) within individual vesicles was observed by fluorescence microscopy. Interestingly, at the early stage of the reaction, the expression efficiency inside the vesicle was remarkably higher than that in the solution outside. The synthesized rsGFP in individual vesicles is safe from attack by proteinase K added to the external aqueous solution. Studies on cell-sized vesicles expressing protein should contribute to a fundamental understanding of certain aspects of living systems and will be useful for practical applications, such as the construction of microreactors. 相似文献
39.
The insect cell-baculovirus expression vector system, widely used for glycoprotein production, is not ideal for pharmaceutical glycoprotein production due to the characteristics of the N-glycans in the expressed products. Insect cells lack several enzymes required for mammalian-type N-glycan synthesis and contain a specific N-acetylglucosaminidase that stunts the growth of chains and a core alpha-1,3-fucosyltransferase that yields potentially allergenic glycoforms. Current knowledge on N-glycan processing in lepidopteran insect cells is summarized, and strategies to develop better glycoprotein expression systems suitable for pharmaceutical glycoprotein production are discussed. 相似文献
40.
Hideto Matsuyama Kentarou Hayashi Taisuke Maki Masaaki Teramoto Noboru Kubota 《应用聚合物科学杂志》2004,93(1):471-474
Microporous high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) hollow fiber membranes were prepared from polyethylene–diisodecyl phthalate solution via thermally induced phase separation. Effect of the polyethylene density on the membrane structure and performance was investigated. The HDPE membrane showed about five times higher water permeability than the LDPE membrane because it had the larger pore and the higher porosity at the outer membrane surface. The formation of the larger pore was owing to both the initial larger structure formed by spinodal decomposition and the suppression of the diluent evaporation from the outer membrane surface due to the higher solution viscosity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 471–474, 2004 相似文献