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881.
Thermally Induced Valence Tautomeric Transition in a Two‐Dimensional Fe‐Tetraoxolene Honeycomb Network 下载免费PDF全文
Jian Chen Dr. Yoshihiro Sekine Yuki Komatsumaru Prof. Dr. Shinya Hayami Prof. Dr. Hitoshi Miyasaka 《Angewandte Chemie (International ed. in English)》2018,57(37):12043-12047
A novel tetraoxolene‐bridged Fe two‐dimensional honeycomb layered compound, (NPr4)2[Fe2(Cl2An)3] ?2 (acetone)?H2O ( 1 ), where Cl2Ann?=2,5‐dichloro‐3,6‐dihydroxy‐1,4‐benzoquinonate and NPr4+=tetrapropylammonium cation, has been synthesized. 1 revealed a thermally induced valence tautomeric transition at T1/2=236 K (cooling)/237 K (heating) between Fem+ (m=2 or 3) and Cl2Ann? (n=2 or 3) that induced valence modulations between [FeIIHSFeIIIHS(Cl2An2?)2(Cl2An.3?)]2? at T>T1/2 and [FeIIIHSFeIIIHS(Cl2An2?)(Cl2An.3?)2]2? at T<T1/2. Even in a two‐dimensional network structure, the low‐temperature phase [FeIIIHSFeIIIHS(Cl2An2?)(Cl2An.3?)2]2? valence set can be regarded as a magnetic chain‐knit network, where ferrimagnetic Δ and Λ chains of [FeIIIHS(Cl2An.3?)]∞ are alternately linked by the diamagnetic Cl2An2?. This results in a slow magnetization behavior attributed to the structure acting as a single‐chain magnet at lower temperatures. 相似文献
882.
Easy‐to‐Attach/Detach Solubilizing‐Tag‐Aided Chemical Synthesis of an Aggregative Capsid Protein 下载免费PDF全文
Dr. Shugo Tsuda Dr. Masayoshi Mochizuki Hiroyuki Ishiba Prof. Dr. Kumiko Yoshizawa‐Kumagaye Prof. Dr. Hideki Nishio Prof. Dr. Shinya Oishi Dr. Taku Yoshiya 《Angewandte Chemie (International ed. in English)》2018,57(8):2105-2109
A solubilizing Trt‐K10 tag was developed for the effective chemical preparation of peptides/proteins with low solubility. The Trt‐K10 tag comprises a hydrophilic oligo‐Lys sequence and a trityl anchor, and can be selectively introduced to a side chain thiol of Cys of deprotected peptides/proteins with a trityl alcohol‐type introducing reagent Trt(OH)‐K10 under acidic conditions. Significantly, the ligation product in the reaction mixture of a thiol‐additive‐free native chemical ligation can be modified directly in a one‐pot manner to facilitate the isolation of the product by high‐performance liquid chromatography. Finally, the Trt‐K10 tag can be readily removed with a standard trifluoroacetic acid cocktail. Using this easy‐to‐attach/detach tag‐aided method, a hepatitis B virus capsid protein that is usually difficult to handle was synthesized successfully. 相似文献
883.
884.
Takaaki Taniguchi Hikaru Tateishi Shinnsuke Miyamoto Kazuto Hatakeyama Chikako Ogata Asami Funatsu Shinya Hayami Yuki Makinose Nobuhiro Matsushita Michio Koinuma Yasumichi Matsumoto 《Particle & Particle Systems Characterization》2013,30(12):1063-1070
Graphene oxide (GO) is an attractive freestanding support that can be decorated with ultrathin organic layers for facile and low‐cost fabrication of novel devices with controllable functional properties and microstructures. Here, it is reported that a hybrid material consisting of an ultrathin iron phthalocyanine (FePc) layer self‐assembled on reduced graphene oxide (rGO) exhibits excellent catalytic activity that is superior to that of commercial Pt/C for an oxygen reduction reaction (ORR). During solution processing, the FePc layer is first self‐organized onto GO sheets and then reduced electrochemically to form an FePc/rGO hybrid electrocatalyst. Kinetics studies reveal that the hybrid architecture affords an ultrafast ORR rate caused by a strongly dominant four‐electron process, and the durability of the catalyst shows significant improvement by forming the hybrid structure. Spectroscopic studies suggest that these advantages are afforded by synergistic effects between FePc and rGO, which are enriched by the hybrid structure and the appropriate reduction step. 相似文献
885.
Microstructural changes after several cycles of the thermomechanical treatment consisting of a small deformation by stress-induced martensitic transformation (fcc to hcp) and subsequent reversion to austenite by heating (referred to as 'training') have been studied by atomic force microscopy in Fe-Mn-Si based shape memory alloys. Well-trained samples contain a uniform distribution of thin martensite plates of the same variant, the widths of which decrease with increasing number of the training cycles, and their distribution becomes more uniform. Such microstructural development by training originates mainly from extremely thin plates (about 1 nm thick) of hcp phase that are still retained together with stacking faults in the austenite even after heating far above the reverse transformation temperature. In the reverse transformation on heating, a martensite plate that looks as though it is apparently one plate is, in fact, split into very thin plates, which indicates that the plate actually consists of extremely thin martensite plates and these thin plates are reverse-transformed one after another by reverse movement of the Shockley partial dislocations at their tips. This mode of reverse transformation ensures a perfect shape memory effect. 相似文献
886.
Shinya Honda Takahito Kumagai Kazuya Tomihashi Yoshihiro Narita 《Journal of sound and vibration》2013
The present paper extends the layerwise optimization (LO) procedure to the maximization problem of the fundamental frequencies of sandwich plates with fibrous composites and low stiffness core layers. Frequencies are calculated by the Ritz method based on a refined zigzag theory (RZT). Polynomial functions which satisfy at least geometrical boundary conditions with boundary indexes are employed as displacement functions, and they enable satisfying arbitrary sets of boundary conditions for rectangular plates. Results of the experimental modal analysis validate the accuracy of the present calculations, and a comparison with results of the classical laminated theory (CLPT) and the first order share deformation theory (FSDT) supports the effectiveness of the present method. Optimized results are compared with other typical sets of lay-up configurations and this shows the LO method as suitable means to the optimization problem for sandwich plates. 相似文献
887.
Nishikawa Hiroyuki Maenosono Shinya Yamaguchi Yukio Okubo Tatsuya 《Journal of nanoparticle research》2003,5(1-2):103-110
This paper presents a simulation study for self-assembling process of colloidal particles into two-dimensional arrays due to capillary immersion force. Discrete element method is used to simulate the dynamics of colloidal particles trapped in a thin liquid film. The previous model is improved in the following two points: a modification of the screening effect of capillary immersion force and introduction of periodic boundary condition. Snapshots provided by the simulations agree well with experimental images taken by atomic force microscopy. The self-assembling process is quantified with pair correlation function and coordination number. At lower coverage, colloidal particles rapidly form small clusters that consist of several particles in the early stage. Subsequently, chain-like structures with some branches are mainly generated. On the other hand, at higher coverage, large domains of hexagonal close-packed (HCP) structures are gradually generated. The rate of the growth of HCP domains is much slower than that of the generation of the small clusters and the chain-like structures. 相似文献
888.
Tsuneo Okubo Shinya Kanayama Hiroyuki Ogawa Masato Hibino Keisuke Kimura 《Colloid and polymer science》2004,282(3):230-235
Macroscopic and microscopic dissipative structural patterns formed in the course of drying a deionized aqueous solution of cationic polyelectrolyte, poly(allylamine hydrochloride) on a cover glass have been observed. Drying times range from 40 min at 45 °C to 450 min at 5 °C, and are insensitive to the polymer concentration. Pattern area shrinks toward the center at the low polymer concentrations, and increases as the concentration increases. A macroscopic broad ring pattern, where the polymer accumulates densely, forms in many cases. Beautiful fractal patterns are observed at the microscopic scale. The fractal dimension increases from 1.2 to 1.6 as polymer concentration increases from 10-6 monoM to 10-2 monoM. The relative rates between the water flow at the drying front and the convection flow of water accompanying the movement of polymer are important for the macroscopic and microscopic pattern formation. 相似文献
889.
890.
Kawashima Shuichi Nishibata Shinya Zhu Peicheng 《Communications in Mathematical Physics》2003,240(3):483-500
We investigate the existence and the asymptotic stability of a stationary solution to the initial boundary value problem for the compressible Navier–Stokes equation in a half space. The main concern is to analyze the phenomena that happens when the fluid blows out through the boundary. Thus, it is natural to consider the problem in the Eulerian coordinate. We have obtained the two results for this problem. The first result is concerning the existence of the stationary solution. We present the necessary and sufficient condition which ensures the existence of the stationary solution. Then it is shown that the stationary solution is time asymptotically stable if an initial perturbation is small in the suitable Sobolev space. The second result is proved by using an L2-energy method with the aid of the Poincaré type inequality.The second author's work was supported in part by Grant-in-Aid for Scientific Research (C)(2) 14540200 of the Ministry of Education, Culture, Sports, Science and Technology and the third author's work was supported by JSPS postdoctoral fellowship under P99217. 相似文献