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51.
Itaru Natori Shizue Natori Hiroyuki Sekikawa Tomoyuki Takahashi Kenji Ogino Kousuke Tsuchiya Hisaya Sato 《Polymer》2010,51(6):1501-3438
The effect of polymer chain structure on the optical and electrical properties are reported for poly(4-diphenylaminostyrene) (PDAS), which was prepared by the living anionic polymerization of 4-diphenylaminostyrene (DAS) with the benzyllithium (BzLi)/N,N,N′,N′-tetramethylethylenediamine (TMEDA) system. The optical properties of PDAS are strongly affected by the stereoregularity of the PDAS polymer chain; intramolecular excimer-forming fluorescence was observed from PDAS with a syndiotactic-rich configuration. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of PDAS were approximately −5.4 and −2.0 eV, respectively, regardless of the polymer chain structure. The hole and electron drift mobilities for PDAS were in the order of 10−4 to 10−5 (cm2/V s) and 10−5 (cm2/V s), respectively, with negative slopes. The distance of each triphenylamino (TPA) group in the polymer chain was a major factor influencing the drift mobility of PDAS. The current-voltage (I-V) characteristics of PDAS were controllable according to the polymer chain structure of PDAS. 相似文献
52.
Several hexaaluminate-related materials were prepared via hydrolysis of alkoxide and powder mixing method for high temperature combustion of CH4 and C3H8, in order to investigate the effect of the concentration of the fuels, O2 and H2O on NOx emission and combustion characteristics. Among the hexaaluminate catalysts, Sr0.8La0.2MnAl11O19− prepared by the alkoxide method exhibited the highest activity for methane combustion and low NOx emission capability. NOx emission at 1500 °C was increased linearly with O2 concentration, whereas water vapor addition decreased NOx emission in CH4 combustion over the Sr0.8La0.2MnAl11O19− catalyst. In the catalytic combustion of C3H8 over the Sr0.8La0.2MnAl11O19− catalyst, the amount of NOx emitted was raised in the temperature range between 1000 and 1500 °C when the C3H8 concentration increased from 1 to 2 vol.%. It was found that NOx emission in this temperature range was reduced effectively by adding water vapor. 相似文献
53.
Dr. Kenichiro Ito Dr. Yoshihiko Matsuda Ayako Mine Kyohei Miyairi Dr. Yoshimi Kikuchi Dr. Atsushi Konishi 《Chembiochem : a European journal of chemical biology》2023,24(2):e202200599
The inhibition of protein-protein interactions (PPIs) is an effective approach for therapy. Owing to their large binding surface areas to target proteins, macrocyclic peptides are suitable molecules for PPI inhibition. In this study, we developed single-chain tandem macrocyclic peptides (STaMPtides) that inhibits the vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2). They were artificially designed to comprise two different VEGFR2-binding macrocyclic peptides linked in tandem by peptide linkers and secreted by Corynebacterium glutamicum. Most potent VEGFR2-inhibitory STaMPtides with length-optimized linkers exhibited >1000 times stronger inhibitory activity than their parental monomeric peptides, possibly due to the avidity effect of heterodimerization. Our approach of using STaMPtides for PPI inhibition may be used to inhibit other extracellular factors, such as growth factors and cytokines. 相似文献
54.
Akane Samizo Makoto Minohara Naoto Kikuchi Kenta Ando Yuta Mazuka Keishi Nishio 《Journal of the American Ceramic Society》2023,106(2):1540-1546
Sn2Nb2−xTaxO7 (x = 0.0–2.0) with pyrochlore structure is a promising material for p-type oxide semiconductors. A systematic study of its Nb/Ta ratio indicated that the hole–generation efficiency of the Nb end (Sn2Nb2O7) was an order of magnitude lower than that of the Ta end (Sn2Ta2O7). Although this occurs due to differences in oxygen-vacancy formation, the origins of the hole–generation efficiencies remain unclear due to limited information on local and global crystal-structure disorders in pyrochlore Sn2Nb2O7 and Sn2Ta2O7. In this study, the crystal structures of Sn2B2O7 (B = Nb, Ta), composed of BO6 octahedra and Sn4O tetrahedra, were investigated using X-ray absorption spectroscopy and X-ray diffraction. A detailed investigation of the local and global crystal structures indicated a larger amount of disorder in the Sn4O tetrahedra in Sn2Nb2O7 compared to Sn2Ta2O7; disorder in the BO6 octahedra occurred only in Sn2Ta2O7. This study indicates that an appropriate selection of the B-site element is vital for suppressing defect and disorder formation in Sn4O tetrahedra and subsequently improving the hole–carrier–generation efficiency. 相似文献
55.
The catalytic dehydro-aromatization reaction over Mo/HZSM-5 catalyst was drastically stabilized by the co-addition of 5.4%
H2 and 1.8% H2O to methane feed at 750 °C, 0.3 MPa and methane space velocity of 3000 mL g−1 h−1, suppressing the coke formation effectively, compared with single hydrogen or steam addition. 相似文献
56.
57.
Chantamanee Poonjarernsilp Noriaki Sano Tawatchai Charinpanitkul Hiroki Mori Takeyuki Kikuchi Hajime Tamon 《Carbon》2011,(14):4920-4927
Single-walled carbon nanohorns (SWCNHs) hybridized with palladium (Pd) nanoparticles were synthesized by a single-step gas-injected arc-in-water method (GI-AIW) with a Pd wire inserted inside the anode hole. In the arc zone, carbon and Pd were vaporized simultaneously, leading to the formation of hybrid material of SWCNHs and Pd nanoparticles due to effective quenching. Based on TEM and CO chemisorption analyses, Pd nanoparticles were found to be embedded inside SWCNH aggregates. The size of Pd nanoparticles, determined by X-ray diffraction, was in the range of 3–6 nm when Pd wires with diameters of 0.1 and 0.3 mm were used. Using a Pd wire with a diameter larger than 0.5 mm results in larger Pd nanoparticles which tend to be exposed to the outer surface of the hybrid material. According to thermogravimetric analyses, the weight fraction of Pd nanoparticles is increased by increasing the Pd wire diameter although the yield of Pd nanoparticles decreased. SWCNHs hybridized with dispersed Pd nanoparticles, synthesized with 0.1 mm Pd wire, exhibited strong anti-oxidation resistance with a highly graphitic structure. 相似文献
58.
Isao Kobayashi Mitsutoshi Nakajima Hiroshi Nabetani Yuji Kikuchi Atsushi Shohno Kazumi Satoh 《Journal of the American Oil Chemists' Society》2001,78(8):797-802
Micron-scale monodisperse oil-in-water (O/W) micropheres (MS) were prepared using a novel microchannel (MC) emulsification
technique. The characteristics of the MS preparation and the O/W-MS prepared were studied. Soybean oil and medium-chain triacyglycerol
(MCT) were used as the disprrsed phase, and physiological saline was used as the continuous phase. Silicon MC with 1 to 3μm-equivalent
channel diameters were employed. A novel MC module was devised to easily recover the O/W-MS prepared. The effects of the channel
shape on the behavior of MS formation, on the MS size, and on the distribution were investigated. An MC with a terrace at
the MC outlet stably yielded micron-scale monodisperse O/W-MS; the MS had diameters of about 5 μm, and their coefficients
of variation were below 9%. Monodisperse food-grade O/W-MS with diameters of about 4 μm could be obtained by using polyglycerol
fatty acid ester as the surfactant. The size and size distribution of the recovered O/W-MS remained almost constant over 60
d, demonstrating their long-term stability. 相似文献
59.
Kumiko Kikuchi Yoko Mizokami Mariko Egawa Hirohisa Yaguchi 《Color research and application》2020,45(2):290-302
In this article, we present an evaluation method for the skin color distribution in the face area. Unlike previous methods that extract a specific area, our method subdivides the entire face into small regions and analyzes detailed, per-frame textures. Our evaluation method for skin color distribution is based on facial feature points and includes segmentation that takes into account the facial skeleton and muscle orientation. The use of facial feature points enables a comparison at relatively equal positions on the face without depending on the shape or size of the individual's face. Our evaluation method is versatile, and as an application, we clarified age-specific features and seasonal variations of facial color distribution. As a result of applying this evaluation method to the facial images of women aged 20 to 78 years, we confirmed that the lightness of the face decreased as age increased. In particular, the decrease in lightness was remarkable in the region along the cheekbone, from the temple to the center of the cheek. Furthermore, we analyzed the seasonal changes of melanin distribution in the face area. This showed that the melanin index increased particularly in the cheekbone area in the summer when the influence of ultraviolet rays became large. Our novel methodology and the data presented in this article will be useful in various fields, such as dermatology, cosmetics, and computer vision. 相似文献
60.
Liquid‐phase sintering of highly Na+ ion conducting Na3Zr2Si2PO12 ceramics using Na3BO3 additive 下载免费PDF全文
Kousuke Noi Kenji Suzuki Naoto Tanibata Akitoshi Hayashi Masahiro Tatsumisago 《Journal of the American Ceramic Society》2018,101(3):1255-1265
Na3Zr2Si2PO12 (NASICON) is a promising material as a solid electrolyte for all‐solid‐state sodium batteries. Nevertheless, one challenge for the application of NASICON in batteries is their high sintering temperature above 1200°C, which can lead to volatilization of light elements and undesirable side reactions with electrode materials at such high temperatures. In this study, liquid‐phase sintering of NASICON with a Na3BO3 (NBO) additive was performed for the first time to lower the NASICON sintering temperature. A dense NASICON‐based ceramic was successfully obtained by sintering at 900°C with 4.8 wt% NBO. This liquid‐phase sintered NASICON ceramic exhibited high total conductivity of ~1 × 10?3 S cm?1 at room temperature and low conduction activation energy of 28 kJ mol?1. Since the room‐temperature conductivity is identical to that of conventional high‐temperature‐sintered NASICON, NBO was demonstrated as a good liquid‐phase sintering additive for NASICON solid electrolyte. In the NASICON with 4.8 wt% NBO ceramic, most of the NASICON grains directly bonded with each other and some submicron sodium borates segregated in particulate form without full penetration to NASICON grain boundaries. This characteristic composite microstructure contributed to the high conductivity of the liquid‐phase sintered NASICON. 相似文献