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921.
Masato Imai Tadahiko Kubota Atsushi Miyazawa Masahiro Aoki Haruna Mori Yuta Komaki Kenji Yoshino 《Crystal Research and Technology》2023,58(3):2200203
Depositions are conducted on monolayer porous membrane at 50 °C by spray pyrolysis using methylaluminoxanes diluted with N-methylpyrrolidone. The solution penetrates the film during spraying and the ultra-thin layers are deposited on the side wall of internal pores. It is suggested that these layers are fine polycrystalline of Al2O3. In the obtained film, most of the pores are exposed on the surface and there is no increase in film thickness. Further, the ionic conductivity is the same as that of the received film, and the thermal stability is improved. This method can be an effective technique for improving the function of the separator used in the lithium-ion batteries. 相似文献
922.
Mizuki Takahashi;Yuki Yamanaka;Shiori Ii;Ayaka Shima;Soma Inaba;Kosei Kubota;Yuta Hattori;Tetsuya Takeuchi;Motoaki Iwaya;Satoshi Kamiyama; 《physica status solidi b》2024,261(11):2400009
For realizing room-temperature continuous-wave operation in core–shell GaN nanowire-based semiconductor lasers, certain device characteristics are required, namely, a low threshold current and low operating voltage. To reduce the operating voltage and inject current into the m-plane multiquantum shell (MQS) active region, a new structure with a tunnel junction and embedded n-GaN is proposed. One of the problems in this proposed device architecture is the high resistance at the tunnel junction layer due to hydrogen passivation in the insufficiently activated p-GaN shell. In situ activation annealing and suppression of re-passivation during subsequent growth are necessary to reduce the operating voltage. Herein, the time and temperature dependence of in situ activation annealing in a reactor to lower the resistance of tunnel junction layers grown on nanowires with nonpolar m-planes is investigated. Subsequent n+-GaN growth is implemented at 550 °C. As a result, the turn-on voltage is observed to be dependent on the activation annealing time and temperature. The lowest turn-on voltage is ≈5.4 V at an activation annealing time of 30 min and activation annealing temperature of 800 °C. 相似文献
923.
Yuto Katsuyama Dr. Yuta Nakayasu Dr. Hiroaki Kobayashi Yasuto Goto Prof. Itaru Honma Prof. Masaru Watanabe 《ChemSusChem》2020,13(21):5762-5768
Hard carbon (HC) is the most promising candidate for sodium-ion battery anode materials. Several material properties such as intensity ratio of the Raman spectrum, lateral size of HC crystallite (La), and interlayer distance (d002) have been discussed as factors affecting anode performance. However, these factors do not reflect the bulk property of the Na+ intercalation reaction directly, since Raman analysis has high surface sensitivity and La and d002 provide only one-dimensional crystalline information. Herein, it was proposed that the crystallite interlayer area (Ai) defined using La, d002, and stacking height (Lc) governs Na+ intercalation behavior of various HCs. It was revealed that various wood-derived HCs exhibited the similar total capacity of approximately 250 mAh g−1, whereas the Na+ intercalation capacity (Ci) was proportional to Ai with the correlation coefficient of R2=0.94. The evaluation factor of Ai was also adaptable to previous reports and strongly correlated with their Ci, indicating that Ai is more widely adaptable than the conventional evaluation methods. 相似文献
924.
925.
Shi Guo Yuta Nishina Alberto Bianco Ccilia Mnard‐Moyon 《Angewandte Chemie (International ed. in English)》2020,59(4):1542-1547
A method for the double functionalization of graphene oxide (GO) under mild alkaline conditions has been developed. Two functional groups were covalently linked to GO in two steps: the first group was attached by an epoxide ring‐opening reaction and the second, bearing an amine function, was covalently conjugated to benzoquinone attached to the GO. The doubly functionalized GO was characterized by several techniques, confirming the sequential covalent modification of the GO surface with two different functional groups. This method is straightforward and the reaction conditions are mild, allowing preservation of the structure and properties of GO. This strategy could be exploited to prepare multifunctional GO conjugates with potential applications in many fields ranging from materials science to biomedicine. 相似文献
926.
The effect of the surface modification of a fluorine-doped tin oxide (FTO) electrode with an Sb-containing mixed metal oxide on the oxidative production of H2O2 from H2O was investigated. The initial faradaic efficiency for H2O2 production (FE(H2O2)) reached 98 % when CuSb2Ox/FTO was used as the anode, as a consequence of the suppression of O2 generation via four-electron oxidation of H2O. InSbOx modification of FTO resulted in a suppression of the oxidative decomposition of H2O2 to O2. The double-layer composite electrode InSbOx/CuSb2Ox/FTO indicated the advantageous traits of both Sb-containing mixed metal oxides, and this composite electrode showed superior FE(H2O2), current-potential dependence, and stability to other electrodes such as CuSb2Ox/FTO, InSbOx/FTO, and Al2O3/BiVO4/FTO. 相似文献
927.
Hisaaki Takeshima Kotaro Satoh Masami Kamigaito 《Journal of polymer science. Part A, Polymer chemistry》2020,58(1):91-100
A series of bio-based vinylphenols or hydroxystyrenes is prepared by simple decarboxylation of various naturally occurring cinnamic acids such as o-, m-, and p-coumaric; caffeic; ferulic; and sinapinic acids, which possess hydroxy groups and other substituents at different positions on the aromatic ring. After protection of the phenolic moieties with trialkylsilyl groups, reversible addition–fragmentation chain-transfer polymerization is accomplished with cumyl dithiobenzoate to afford various bio-based hydroxyl-protected polystyrenes with controlled molecular weights and narrow molecular weight distributions. Subsequent deprotection of the silyl groups under mild conditions results in a series of well-defined functionalized polystyrenes possessing different numbers (mono-, di-, tri-) of hydroxy groups at different positions (o, m, p). The obtained functionalized polystyrenes show unique thermal properties depending on the substituents, and those with phenol and catechol groups serve as reducing agents for silver ions. © 2019 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 91–100 相似文献
928.
Yuta Watanabe Dr. Yohei Haketa Dr. Kazuto Nakamura Shunsuke Kaname Dr. Nobuhiro Yasuda Prof. Hiromitsu Maeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(30):6767-6772
The introduction of arylethynyl moieties at the pyrrole α- and β-positions of dipyrrolyldiketone BF2 complexes as anion-responsive π-electronic molecules was investigated. The arylethynyl-substituted derivatives formed a variety of anion complexes with planar [1+1]- and interlocked [2+1]-type structures in solution and in the solid state. The derivatives with long alkyl chains in the introduced arylethynyl groups also formed mesophases in the form of ion pairs of the anion complexes and a counter cation. The geometries of the constituent anion complexes affected the packing modes of the dimension-controlled assemblies. 相似文献
929.
Prof. Chihiro Kachi-Terajima Tasuku Eiba Rikako Ishii Prof. Hitoshi Miyasaka Yuta Kodama Prof. Toshiaki Saito 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22232-22237
Spin ice is an exotic type of magnetism displayed by bulk rare-earth pyrochlore oxides. We discovered a spin ice-like magnetic relaxation of [{Mn(saltmen)}4{Mn(CN)6}](ClO4)⋅13 H2O (saltmen2−=N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminate)). This magnetic system can be considered as a two-dimensional network of MnIII salen-type single-molecule magnets (SMMs) in which each SMM unit (ST=4) has two orthogonally oriented axial anisotropies and is connected ferromagnetically through the [Mn(CN)6]3− unit (S=1). This work illustrates that a two-dimensional SMM network with competition between the ferromagnetic interaction and local noncollinear magnetic anisotropies on SMMs is a new type of magnetic system exhibiting slow relaxation of magnetization with a Davidson-Cole-type broad distribution of the relaxation time. 相似文献
930.
Yuta Shiina Dr. Yuto Kage Prof. Dr. Ko Furukawa Dr. Heng Wang Prof. Dr. Hirofumi Yoshikawa Prof. Dr. Hiroyuki Furuta Prof. Dr. Nagao Kobayashi Prof. Dr. Soji Shimizu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(50):22910-22918
Orientational control of functional molecules is essential to create complex functionalities as seen in nature; however, such artificial systems have remained challenge. Herein, we have succeeded in controlling rotational isomerism of μ-oxo silicon phthalocyanine (SiPc) oligomers to achieve an external-stimuli-responsive orientational ordering using intermolecular interactions of tetrathiafulvalene (TTF). In this system, three modes of orientations, free rotation, eclipsed conformation, and staggered conformation, were interconverted in response to the oxidation states of TTF, which varied interactions from association due to formation of mixed-valence TTF dimer to dissociation due to electrostatic repulsion between TTF dications. Furthermore, a stable performance of oligomers as a cathode material in a Li-ion battery proved that the one-dimensionally stacked, rotatable structure of SiPc oligomers is useful to control the orientation of functional molecules toward molecular electronics. 相似文献