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51.
Photovoltage mechanism for room light conversion of citrate stabilized silver nanocrystal seeds to large nanoprisms 总被引:2,自引:0,他引:2
Wu X Redmond PL Liu H Chen Y Steigerwald M Brus L 《Journal of the American Chemical Society》2008,130(29):9500-9506
We investigate the photoconversion of aqueous 8 nm Ag nanocrystal seeds into 70 nm single crystal plate nanoprisms. The process relies on the excitation of Ag surface plasmons. The process requires dioxygen, and the transformation rate is first-order in seed concentration. Although citrate is necessary for the conversion, and is consumed, the transformation rate is independent of citrate concentration. We propose a mechanism that accounts for these features by coupling the oxidative etching of the seed and the subsequent photoreduction of aqueous Ag(+). The reduced Ag deposits onto a Ag prism of specific size that has a cathodic photovoltage resulting from plasmon "hot hole" citrate photo-oxidation. This photovoltage mechanism also explains recent experimental results involving single and dual wavelength irradiation and the core/shell synthesis of Ag layers on Au seeds. 相似文献
52.
Cationic cyclocholamides; toroidal facial amphiphiles with potential for anion transport 总被引:1,自引:0,他引:1
Whitmarsh SD Redmond AP Sgarlata V Davis AP 《Chemical communications (Cambridge, England)》2008,(31):3669-3671
Cholic acid has been transformed into cyclotrimeric and cyclotetrameric toroidal amphiphiles with inward-directed ammonium substituents; the cyclotrimer effects the transport of chloride anions across vesicle bilayer membranes. 相似文献
53.
Biancardo M Bignozzi C Doyle H Redmond G 《Chemical communications (Cambridge, England)》2005,(31):3918-3920
A molecular photonic logic gate is demonstrated by integrating electrical (potential) and chemical (ionic) switching functions into molecules attached at an externally addressable semiconductor substrate. 相似文献
54.
Don Redmond 《Mathematische Annalen》1976,224(3):247-268
55.
D. McDonnell B. Redmond L. J. Crane 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2013,64(5):1599-1607
This paper first examines the mass transfer from a vertical flat surface of a soluble material due to natural convection. A perturbation term is then introduced into the stream function to model the introduction of a constant counterflow. The effect this counterflow has on both the overall mass transfer and the overall velocity profile is studied in detail. 相似文献
56.
Shane P. Redmond 《Discrete Mathematics》2007,307(21):2449-2452
This note provides some minor corrections to the article “On zero-divisor graphs of small finite commutative rings”. 相似文献
57.
Maria Hepel Lumbini Indee Dela-Moss Haley Redmond 《Journal of Solid State Electrochemistry》2014,18(5):1251-1260
The interactions of various types of cations with the tungsten trioxide lattice have been investigated to evaluate possible intercalation of these cations and the occurrence of lattice polarization leading to the near-surface structural lattice damage. The interactions of cations, such as the large monovalent cations (K+, Et4N+, CtMe3N+ cations), transition metal dications (Ni2+), heavy metal ions (Cd2+), and representative lanthanides (La3+) and actinides (Th4+), in competition with intercalation of H+ ions have been investigated using pulse-nanogravimetric technique. The effects of these cations in electrochromic processes of WO3 proceeding during cathodic reduction have been assessed. For all of the metal ions studied, a large increase in the apparent mass uptake (up to eightfold) in comparison to pure H+ ion ingress was observed upon the film coloration induced by a cathodic potential pulse. The experiments indicate that the apparent mass gains, although large, are insufficient to confirm predominant contribution of metal ions in the ion transport along the channels in WO3 lattice. The lower decoloration rate in the case of Ni2+ ions, in comparison to H+ and other transition metal cations (Cd2+), has been attributed to a slow dissociation of Ni2+ ions from lattice-bound oxygen atoms. For et4N+ cation, which is too large to enter channels in WO3, a dissociative reduction of the WO3 and severe lattice damage was observed. Among the metal ions investigated, only K+ ions have been found to cause a dissociative reduction of WO3 and near-surface lattice damage. Strong lattice polarization effects and irreversible binding have been found for La3+ and Th4+ cations. 相似文献
58.
Reflection of plane waves from the boundary of a pre-stressed compressible elastic half-space 总被引:2,自引:0,他引:2
The effect of pre-stress on the propagation and reflection ofplane waves in an incompressible isotropic elastic half-spacehas been examined recently by the authors (Ogden & Sotiropoulos,1997). In the present paper the corresponding analysis for compressiblematerials is detailed. In the two-dimensional context consideredfor incompressible materials the (homogeneous) plane waves werenecessarily shear waves. By contrast, in the compressible contextpure shear waves can propagate only in specific directions inthe considered principal plane and, in a general direction,a quasi-shear wave may be accompanied by a quasi-longitudinalwave, as is the case in the anisotropic linear theory. The dependenceof the (in-plane) slowness section on the pre-stress (and finitedeformation) and on the choice of constitutive law is elucidated.This information is used to determine the reflection coefficientsfor reflection of either a (quasi-) shear wave or a (quasi-)longitudinal wave from the boundary of the half-space and tocharacterize the different cases which arise depending on thegeometry of the slowness section. The theoretical results are illustrated by numerical calculationsfor the range of possible types of behaviour with referenceforms of strain-energy function and different states of finitedeformation and to the question of stability of the half-space. 相似文献
59.
Kyne SH Percy JM Pullin RD Redmond JM Wilson PG 《Organic & biomolecular chemistry》2011,9(24):8328-8339
Difluoroalkenylzinc reagents prepared from 1-(2'-methoxy-ethoxymethoxy)-2,2,2-trifluoroethane and 1-(N,N-diethylcarbamoyloxy)-2,2,2-trifluoroethane at ice bath temperatures underwent Negishi coupling with a range of aryl halides in a convenient one pot procedure. While significant differences between the enol acetal and carbamate reagents were revealed, the Negishi protocol compared very favourably with alternative coupling procedures in terms of overall yields from trifluoroethanol. 相似文献
60.
Redmond SM Creedon KJ Kansky JE Augst SJ Missaggia LJ Connors MK Huang RK Chann B Fan TY Turner GW Sanchez-Rubio A 《Optics letters》2011,36(6):999-1001
We have demonstrated active coherent beam combination (CBC) of up to 218 semiconductor amplifiers with 38.5?W cw output using up to eleven one-dimensional 21-element individually addressable diode amplifier arrays operating at 960?nm. The amplifier array elements are slab-coupled-optical-waveguide semiconductor amplifiers (SCOWAs) set up in a master-oscillator-power-amplifier configuration. Diffractive optical elements divide the master-oscillator beam to seed multiple arrays of SCOWAs. A SCOWA was phase actuated by adjusting the drive current to each element and controlled using a stochastic-parallel-gradient-descent (SPGD) algorithm for the active CBC. The SPGD is a hill-climbing algorithm that maximizes on-axis intensity in the far field, providing phase locking without needing a reference beam. 相似文献