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41.
Photoelectrochemical decomposition of water on nanocrystalline BiVO4 film electrodes under visible light 总被引:1,自引:0,他引:1
Sayama K Nomura A Zou Z Abe R Abe Y Arakawa H 《Chemical communications (Cambridge, England)》2003,(23):2908-2909
The nanocrystalline BiVO4 film electrode on conducting glass showed an excellent efficiency (IPCE = 29% at 420 nm) for the decomposition of water under visible light. 相似文献
42.
Takahiro Gunji Takayoshi Tozune Hironori Kaburaki Kouji Arimitsu Yoshimoto Abe 《Journal of polymer science. Part A, Polymer chemistry》2013,51(22):4732-4741
Polymethyl(alkoxy)siloxane copolymers, poly(MTES‐co‐TEOS), and poly(MTMS‐co‐TMOS), are prepared by acid‐catalyzed controlled hydrolytic co‐polycondensation of methyl(trialkoxy)silane MeSi(OR)3 (R = Et (MTES) and Me (MTMS)) and tetra‐alkoxysilane Si(OR)4 (R = Et (TEOS) and Me (TMOS)), respectively. The products are purified by fractional precipitation to provide polymethyl(alkoxy)siloxane copolymers with molecular weight 1000–10,000 (poly(MTES‐co‐TEOS)) or 1700–100,000 (poly(MTMS‐co‐TMOS)) that are stable to self‐condensation. These polymers are soluble in common organic solvents except for hexane, and form flexible and transparent free‐standing films with a tensile strength of 4.0–10.0 MPa. The structure of the polymethyl(alkoxy)siloxane copolymers is thought to be a random or a block co‐polymer. They are found to provide coating films with an adhesive strength up to 10, a refractive index of 1.36–1.40, and a dielectric constant of 3.5–3.6. The products also show better weathering stability than polyethoxysiloxane due to the hydrolytic polycondensation of TEOS. Field emission‐scanning electron micrography analysis reveals that coating films are composed of a micro‐phase separated structure. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4732–4741 相似文献
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45.
Megumi Kubo Takashi Kikukawa Seiji Miyauchi Akiteru Seki Masakatsu Kamiya Tomoyasu Aizawa Keiichi Kawano Naoki Kamo Makoto Demura 《Photochemistry and photobiology》2009,85(2):547-555
Halorhodopsin (HR) acts as a light‐driven chloride pump which transports a chloride ion from the extracellular (EC) to the cytoplasmic space during a photocycle reaction that includes some photointermediates initiated by illumination. To understand the chloride uptake mechanisms, we focused on a basic residue Arg123 of HR from Natronomonas pharaonis (NpHR), which is the only basic residue located in the EC half ion channel. By the measurements of the visible absorption spectra in the dark and the light‐induced inward current through the membrane, it was shown that the chloride binding and transport ability of NpHR completely disappeared by the change of arginine to glutamine. From flashphotolysis analysis, the photocycle of R123Q differed from that of wildtype NpHR completely. The response of the R123H mutant depended on pH. These facts imply that the positive charge at position 123 is essential for chloride binding in the ground state and for the chloride uptake under illumination. On the basis of the molecular structures of HR and the anion‐transportable mutants of bacteriorhodopsin, the effects of the positive charge and the conformational change of the Arg123 side chain as well as the chloride‐pumping mechanism are discussed. 相似文献
46.
Yuko Okamoto Toshimasa Tanaka Hironori Kokubo 《Journal of computer-aided molecular design》2010,24(8):699-712
We performed replica-exchange molecular dynamics (REMD) simulations of six ligands to examine the dependency of their free
energy landscapes on charge parameters and solvent models. Six different charge parameter sets for each ligand were first
generated by RESP and AM1-BCC methods using three different conformations independently. RESP charges showed some conformational
dependency. On the other hand, AM1-BCC charges did not show conformational dependency and well reproduced the overall trend
of RESP charges. The free energy landscapes obtained from the REMD simulations of ligands in vacuum, Generalized-Born (GB),
and TIP3P solutions were then analyzed. We found that even small charge differences can produce qualitatively different landscapes
in vacuum condition, but the differences tend to be much smaller under GB and TIP3P conditions. The simulations in the GB
model well reproduced the landscapes in the TIP3P model using only a fraction of the computational cost. The protein-bound
ligand conformations were rarely the global minimum states, but similar conformations were found to exist in aqueous solution
without proteins in regions close to the global minimum, local minimum or intermediate states. 相似文献
47.
Non-extractable photoinitiators based on thiol-functionalized benzophenones and thioxanthones 总被引:1,自引:0,他引:1
Hironori Matsushima Qin Li Masamitsu Shirai Charles E. Hoyle 《European Polymer Journal》2010,46(6):1278-1287
Non-extractable photoinitiators could be advantageous for use in biological, electronic, and food packaging applications. Therefore, thioxanthone and benzophenone derivatives were synthesized from 1,6-hexane dithiol and chlorinated benzophenone or thioxanthone. The efficiency of thiol-functionalized photoinitiators in combination with amine co-initiators was compared to benzophenone and isopropylthioxanthone with amine co-initiators, and the cleavage of photoinitiator 2,2-dimethoxy-1,2-diphenylethan-1-one in acrylic resins. The reaction kinetics were analyzed using photo-differential scanning calorimetry and real-time FTIR. Coating physical properties were evaluated by pendulum and pencil hardness, steel-wool scratch and mandrel bend tests. The non-extractable photoinitiators had higher absorbance than their benzophenone or isopropylthioxanthone counterparts due to the sulfide substitution on the phenyl ring, and the free thiol groups reacted with the acrylate by either an amine catalyzed Michael addition or a free-radical chain process. The combination of thiol-functionalized photoinitiators with secondary amines provides an efficient photoinitiator system that is locked into the photopolymerized network and cannot be extracted with typical solvents. 相似文献
48.
Hironori Tohmyoh M. A. Salam Akanda Masumi Saka 《Applied Physics A: Materials Science & Processing》2011,103(2):285-291
A mechanical testing methodology for determination of elastic-plastic properties of very thin metallic wires using small-span
bending under lateral load is described. Sufficient strain is locally developed in the tested section of wire by unsymmetrical
bending with two opposite probes where one end of the wire is fixed on a substrate with rigid joint by Joule heat welding.
From the load-displacement relationships obtained experimentally, Young’s modulus is determined by analytical formulation.
Moreover, yield stress and hardening modulus of the wire are identified using an optimization strategy with finite-element
analyses. The thin Pt wires with a nominal diameter of about 625 nm are examined by the testing scheme and the wires are found
to have higher yield stress compared to bulk Pt. 相似文献
49.
This paper proposes a method of structuring public policy by incorporating reciprocal expectation analysis. The proposed method is characterized by three components: identification of the problem structure perceived by stakeholders using cognitive maps, policy structuring analysis with a value–driver matrix and a reciprocal expectation matrix, and feasibility analysis of agreements among the stakeholders. The three types of relationship among stakeholders are derived from the feasibility analysis, which are “Dosho-imu”, “Isho-imu”, and “Domu”. Three tests of feasibility to reach the agreement are then proposed: “information-sharing test”, “bargaining test”, and “reframing test”. A case study is presented, applying the method to strategic transportation planning in the Kanto region of Japan. Finally, the potential functions of the proposed method in practice are discussed. 相似文献
50.
Hironori FukumotoTomoyuki Esumi Jun IshiharaSusumi Hatakeyama 《Tetrahedron letters》2003,44(44):8047-8049
The first total synthesis of (±)-erythravine was achieved in thirteen steps from 3,4-dimethoxyphenethylamine using ring closing dienyne metathesis as the key step. 相似文献