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排序方式: 共有238条查询结果,搜索用时 20 毫秒
31.
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Jialei Du Prof. Zuofeng Chen Dr. Shengrong Ye Prof. Benjamin J. Wiley Prof. Thomas J. Meyer 《Angewandte Chemie (International ed. in English)》2015,54(7):2073-2078
Copper metal is in theory a viable oxidative electrocatalyst based on surface oxidation to CuIII and/or CuIV, but its use in water oxidation has been impeded by anodic corrosion. The in situ formation of an efficient interfacial oxygen‐evolving Cu catalyst from CuII in concentrated carbonate solutions is presented. The catalyst necessitates use of dissolved CuII and accesses the higher oxidation states prior to decompostion to form an active surface film, which is limited by solution conditions. This observation and restriction led to the exploration of ways to use surface‐protected Cu metal as a robust electrocatalyst for water oxidation. Formation of a compact film of CuO on Cu surface prevents anodic corrosion and results in sustained catalytic water oxidation. The Cu/CuO surface stabilization was also applied to Cu nanowire films, which are transparent and flexible electrocatalysts for water oxidation and are an attractive alternative to ITO‐supported catalysts for photoelectrochemical applications. 相似文献
33.
Panzner MJ Bilinovich SM Youngs WJ Leeper TC 《Chemical communications (Cambridge, England)》2011,47(46):12479-12481
The X-ray crystal structure, NMR binding studies, and enzyme activity of silver(I) metallated hen egg white lysozyme are presented. Primary bonding of silver is observed through His15 with secondary bonding interactions coming from nearby Arg14 and Asp87. A covalently bound nitrate completes a four coordinate binding pocket. 相似文献
34.
The diffusion of110Ag in Cu2O has been measured by a serial-sectioning technique as a function of temperature (700–1132°C) and oxygen partial pressure (6 × 10?6 ?8 × 10?2 atm). The data are fit to the defect model for Cu2O developed by the authors in the preceding paper. Silver ions have a larger impurity-vacancy binding free energy and/or a larger jump frequency for the singly charged cation vacancies relative to that for the neutral cation vacancies. The activation enthalpies for the diffusion of copper and silver ions in Cu2O are nearly equal, but the absolute value of D1Ag is about three times larger than D1Cu even though the silver ion is 31% larger than the copper ion. 相似文献
35.
The absorption band edge of single-crystal orthorhombic GeS has been measured in all three polarizations at 4.2, 77 and 300°K. Strong excitonic absorption is observed for E ∥ a, and the transitions in this direction are identified as direct-allowed. Transitions in the E ∥ b and E ∥ c polarizations are tentatively identified as direct forbidden and direct allowed, respectively, with values for Eg similar to those found for E ∥ a. Evidence for the partially two-dimen?ional character of GeS is discussed. 相似文献
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Graft distribution functions have been derived from random grafting statistics. Among the functions, the weight fraction of ungrafted backbone chains, the molecular weight distribution of the ungrafted backbone chains and the GPC apparent molecular weight distribution of the graft copolymer have been found to agree with experimental values determined for a graft copolymer system in which grafting was expected to be random. The other functions, which are not directly measurable, are therefore probably also correct. In analytical work the entire set of graft distribution functions may be computed for a graft copolymer system from the following experimental data: (1) molecular weight distribution of the starting backbone chains; (2) the chemical composition of the mixture of the graft copolymer and ungrafted backbone; (3) the graft side-chain molecular weight distribution, which may be assumed to be identical to that of the ungrafted homopolymer separable from the reaction mixture. 相似文献
39.
Nuclear spin-lattice relaxation-time measurements of 51V in A-15-phase V0.75-xGa0.25+x have been made in both well-annealed and neutron-irradiated samples. A tight-binding analysis of the results indicates a strong correlation of Tc with the density of states at the Fermi level in the δ-subbands. 相似文献
40.
Xiong Y Chen J Wiley B Xia Y Aloni S Yin Y 《Journal of the American Chemical Society》2005,127(20):7332-7333
Uniform cubooctahedral nanoparticles of Pd were synthesized using a modified polyol process. Like the silver system, the Pd nanoparticles underwent dissolution due to oxidative etching by Cl-/O2. In the early stage of etching, the twinned particles in a sample were selectively removed to leave behind uniform, single-crystal cubooctahedra. If the etching was allowed to continue, the single-crystal cubooctahedra were also attacked and partially dissolved. Understanding the role of oxidative etching is critical to the achievement of both uniform shape and size. 相似文献