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91.
Luís Santos Pascal Martin Jalal Ghilane Pierre-Camille Lacaze Hyacinthe Randriamahazaka Luisa Maria Abrantes Jean-Christophe Lacroix 《Electrochemistry communications》2010,12(7):872-875
The electrodeposition of poly(3,4-ethylenedioxythiophene) (PEDOT) films from aqueous surfactant solution through a two-dimensional poly(styrene) (PS) template onto indium tin oxide (ITO) substrate has been investigated. The polymer grows in the interstitial spaces of the self-assembled PS spheres which were subsequently removed by dissolution in tetrahydrofuran (THF). Surface characterization by scanning electron microscopy (SEM) and atomic force microscopy (AFM) reveals that two-dimensional nanoporous honeycomb PEDOT structures can easily be obtained by using PS spheres of different sizes. Gold electrodeposition onto the nanostructured PEDOT electrode was investigated and SEM images show preferential formation of nanoparticles (NP) on the wall and the rim of the PEDOT film but metal clusters inside the pores are also observed. 相似文献
92.
Wenjun Tang Dr. Andrew G. Capacci Xudong Wei Dr. Wenjie Li Dr. Andre White Dr. Nitinchandra D. Patel Jolaine Savoie Joe J. Gao Sonia Rodriguez Dr. Bo Qu Dr. Nizar Haddad Dr. Bruce Z. Lu Dr. Dhileepkumar Krishnamurthy Dr. Nathan K. Yee Dr. Chris H. Senanayake Dr. 《Angewandte Chemie (International ed. in English)》2010,49(34):5879-5883
93.
94.
Ekaterina P. Nesterenko Pavel N. Nesterenko Damian Connolly Flavie Lacroix Brett Paull 《Journal of chromatography. A》2010,1217(14):2138-2146
A new method for the fixation of polymethacrylate monoliths within titanium tubing of up to 0.8 mm I.D. for use as a chromatographic column under elevated temperatures and pressures is described. The preparation of butyl methacrylate–ethylene dimethacrylate-based monolithic stationary phases with desired porous structures was achieved within titanium tubing with pre-oxidised internal walls. The oxidised titanium surface was subsequently silanised with 3-trimethoxysilylpropyl methacrylate resulting in tight bonding of butyl methacrylate porous monolith to the internal walls, providing stationary phase stability at column temperatures up to 110 °C and at operating column pressure drops of >28 MPa. The titanium housed monoliths exhibited a uniform and dense porous structure, which provided peak efficiencies of up to 59,000 theoretical plates per meter when evaluated for the separation of small molecules in reversed-phase mode, under optimal conditions (achieved at 15 μL/min and temperature of 110 °C for naphthalene with a retention factor, k = 0.58). The developed column was applied to the reversed-phase isocratic separation of a text mixture of pesticides. 相似文献
95.
By varying the absorption coefficient and width of an intralipid-India ink solution in a quasi-one-dimensional experiment, we investigate the transition between the ballistic and the diffusive regimes. The medium's attenuation coefficient changes abruptly between two different values within a single mean free path. This problem is analyzed both experimentally and theoretically, and it is demonstrated that the transition location depends on the scattering coefficient as well as on the measuring solid angle. 相似文献
96.
Andre L. Barbieri G.F. de Arruda Francisco A. Rodrigues Odemir M. Bruno Luciano da Fontoura Costa 《Physica A》2011,390(3):512-518
An entropy-based image segmentation approach is introduced and applied to color images obtained from Google Earth. Segmentation refers to the process of partitioning a digital image in order to locate different objects and regions of interest. The application to satellite images paves the way to automated monitoring of ecological catastrophes, urban growth, agricultural activity, maritime pollution, climate changing and general surveillance. Regions representing aquatic, rural and urban areas are identified and the accuracy of the proposed segmentation methodology is evaluated. The comparison with gray level images revealed that the color information is fundamental to obtain an accurate segmentation. 相似文献
97.
David Bergman Andre A. Cire Willem-Jan van Hoeve Tallys Yunes 《Journal of Heuristics》2014,20(2):211-234
In this paper we introduce a new method for generating heuristic solutions to binary optimization problems. We develop a technique based on binary decision diagrams. We use these structures to provide an under-approximation to the set of feasible solutions. We show that the proposed algorithm delivers comparable solutions to a state-of-the-art general-purpose optimization solver on randomly generated set covering and set packing problems. 相似文献
98.
Y. Lacroix 《Israel Journal of Mathematics》2002,132(1):253-263
LetG denote the set of decreasingG: ℝ→ℝ withGэ1 on ]−∞,0], and ƒ
0
∞
G(t)dt⩽1. LetX be a compact metric space, andT: X→X a continuous map. Let μ denone aT-invariant ergodic probability measure onX, and assume (X, T, μ) to be aperiodic. LetU⊂X be such that μ(U)>0. Let τ
U
(x)=inf{k⩾1:T
k
xεU}, and defineG
U
(t)=1/u(U)u({xεU:u(U)τU(x)>t),tεℝ We prove that for μ-a.e.x∈X, there exists a sequence (U
n
)
n≥1
of neighbourhoods ofx such that {x}=∩
n
U
n
, and for anyG ∈G, there exists a subsequence (n
k
)
k≥1
withG
U
n
k
↑U weakly.
We also construct a uniquely ergodic Toeplitz flowO(x
∞,S, μ), the orbit closure of a Toeplitz sequencex
∞, such that the above conclusion still holds, with moreover the requirement that eachU
n
be a cylinder set.
In memory of Anzelm Iwanik 相似文献
99.
100.
Abstact We describe a numerical method devised to calculate the lower-order modes of optical waveguides with two-dimensional transverse index profiles. This method is based on finite-difference approximation of the scalar wave equation and the minimization of the error in the field shape of a mode. The field correction method can be applied to waveguides with large index steps and generates the mode's scalar propagation constant and its field. To test the field correction method, it is applied to a three-layer optical fibre and the results are compared with exact solutions. The error in the calculations of the modal effective indices is found to be of the order of 10-6. Example mode calculations are given for fused couplers and rib waveguides. 相似文献