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31.
32.
Njoki PN Jacob A Khan B Luo J Zhong CJ 《The journal of physical chemistry. B》2006,110(45):22503-22509
The understanding of how the formation of metal nanoparticles in aqueous solutions is influenced by the presence of presynthesized nanoparticles is important for precise control over size, shape, and composition of nanoparticles. New insights into the catalytic mechanism of Pt nanoparticles are gained by studying the formation of gold nanoparticles from the reduction of AuCl(4)(-) in aqueous solution in the presence of presynthesized Pt nanoparticles as a model system. The measurement of changes of the surface plasmon resonance band of gold nanoparticles, along with TEM analysis of particle size and morphology, provided an important means for assessing the reaction kinetics. The reductive mediation of Pt-H species on the Pt nanocrystal surface is believed to play an important role in the Pt-catalyzed formation of gold nanoparticles. This important physical insight is evidenced by comparison of the rates of the Pt-catalyzed formation of gold nanoparticles in the presence and in the absence of hydrogen (H(2)), which adsorb dissociatively on a Pt nanocrystal surface forming Pt-H species. Pt-H effectively mediates the reduction of AuCl(4)(-) toward the formation of gold nanoparticles. Implications of the findings to the controllability over size, composition, and morphology of metal nanoparticles in the aqueous synthesis environment are also discussed. 相似文献
33.
Wex B Kaafarani BR Danilov EO Neckers DC 《The journal of physical chemistry. A》2006,110(51):13754-13758
Six aromatic compounds with embedded thiophenes differing in the number of rings (2-5) and thiophene orientation along the long axis of the molecule (syn, anti) were investigated. Photophysical properties, steady-state absorption, fluorescence, phosphorescence, lifetimes, quantum yields, and a comprehensive time-resolved spectroscopic analysis (femtosecond and nanosecond transient absorption spectroscopy) have been studied as a function of molecular structure. 相似文献
34.
A Lanczos potential for an arbitrary Petrov type D vacuum spacetimes, using the compacted spin coefficient formalism (or GHP-formalism),
has been obtained; which in turn leads to a solution of Weyl-Lanczos equations. 相似文献
35.
A loopless graph on n vertices in which vertices are connected at least by a and at most by b edges is called a(a,b,n)-graph. A(b,b,n)-graph is called(b,n)-graph and is denoted by K_n~b(it is a complete graph), its complement by K_n~b. A non increasing sequence π =(d_1,…,d_n) of nonnegative integers is said to be(a,b,n) graphic if it is realizable by an(a,b,n)-graph. We say a simple graphic sequence π=(d_1,…,d_n) is potentially K_4-K_2∪K_2-graphic if it has a a realization containing an K_4-K_2∪K_2 as a subgraph where K_4 is a complete graph on four vertices and K_2∪K_2 is a set of independent edges. In this paper, we find the smallest degree sum such that every n-term graphical sequence contains K_4-K_2∪K_2 as subgraph. 相似文献
36.
The aim of this article is to investigate the autotopism group of a semifield of order p 4, p is an odd prime, admitting a four-group of automorphisms E? Z 2 × Z 2 acting freely on A. 相似文献
37.
Hayat T. Ahmed Bilal Abbasi F. M. Alsaedi A. 《Journal of Thermal Analysis and Calorimetry》2019,137(4):1359-1367
This paper reports numerical study for peristalsis of Carreau–Yasuda nanofluid in a symmetric channel. Constant magnetic field is applied. Modified Darcy’s law and nonlinear thermal radiation effects are considered. Viscous dissipation and Ohmic heating effects are also present. Long wavelength and small Reynolds number are considered. Resulting nonlinear problems are solved numerically. Graphical illustrations depict that temperature increases for larger Hartmann number and it decays for thermophoresis parameter.
相似文献38.
Nonlinear Dynamics - This work presents some experimental results for resonant nonlinear response of hyperelastic plates for 1:2 internal resonance. Previously developed topology optimization... 相似文献
39.
Journal of Russian Laser Research - We design a miniaturized and highly-sensitive biosensor based on a photonic-crystal aslant cavity (AC) to detect protein concentrations. The AC has seven ring... 相似文献
40.
Sh. Bilal 《Differential Equations》2014,50(2):147-161
We consider the properties of the positiveness, fractional power, boundedness, and separation of the singular Sturm-Liouville operator in a weighted space depending on the behavior of its coefficients. We derive necessary and sufficient conditions for its positiveness, trace class property, boundedness, and separation. 相似文献