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201.
202.
Roman Zieba Cdric Desroches Frdric Chaput Marcus Carlsson Bertil Eliasson Cesar Lopes Mikael Lindgren Stephane Parola 《Advanced functional materials》2009,19(2):235-241
The synthesis of trans‐di(arylalkynyl)diphosphine platinum(II) complexes bearing trialkoxysilane groups is described, as well as the preparation of siloxane‐based hybrid materials from organometallic chromophores through a modified sol–gel process. Glass materials prepared from trans‐[P(n–Bu)3]2Pt[(C≡C–p–C6H4–C≡C–p–C6H4–CH2O(CO)NH(CH2)3Si(OC2H5)3]2 generally show spectral transmittance, absorption and luminescence similar to that of solutions reported in the literature. Measurements of optical power limiting for the hybrid glass are carried out, and show broadband nonlinear absorption throughout the whole visible wavelength range with clamping values in the range 0.2–7 µJ at 120 mM chromophore concentration. The sol–gel process using urethane‐propyltriethoxysilane‐functionalized chromophores as precursors appears to be a valid method for formation of robust silicate materials with grafted diarylethynyl Pt(II) complexes for OPL devices. 相似文献
203.
Summary This study documents a decade of mainstream research output by European economics institutions. In contrast to previous European
economics departmental rankings, we investigate the changing pattern of the ranking over two subperiods and a total decade.
The validity of our bibliometric approach is demonstrated by a comparison with gradings of UK economic departments in the
2001 Research Assessment Exercise (RAE). We also provide some explanation of the ranking based on regional factors and institutional
features. Strong evidence for the 'institutional oligopoly' of editors and authors hypothesis is found. However, in a dynamic
context this departmental concentration of authorship and editorial board membership does not represent a 'closed shop'. We
find several departments entering the centre stage of economic mainstream for the first time towards the end of the 1990s. 相似文献
204.
Stéphane Rollier 《变频器世界》2009,(3):37-38
除了诸如《京都协议书》等政治策略所带来的动力和压力之外,多种形式能源不断增长的成本以及"更洁净"动力源的搜寻也在推动着对诸如太阳能等替代能源的关注。许多新设计不断涌现,从而最有效和高效地利用这些能源。这些设计具有当今电子技术的支持,其中包括电流传感器。 相似文献
205.
We explore a dual-network architecture with self-refreshing memory (Ans and Rousset 1997) which overcomes catastrophic forgetting in sequential learning tasks. Its principle is that new knowledge is learned along with an internally generated activity reflecting the network history. What mainly distinguishes this model from others using pseudorehearsal in feedforward multilayer networks is a reverberating process used for generating pseudoitems. This process, which tends to go up to network attractors from random activation, is more suitable for capturing optimally the deep structure of previously learned knowledge than a single feedforward pass of activity. The proposed mechanism for ?transporting memory? without loss of information between two different brain structures could be viewed as a neurobiologically plausible means for consolidation in long-term memory. Knowledge transfer is explored with regard to learning speed, ability to generalize and vulnerability to network damages. We show that transfer is more efficient when two related tasks are sequentially learned than when they are learned concurrently. With a self-refreshing memory network knowledge can be saved for a long time and therefore reused in subsequent acquisitions. 相似文献
206.
Rami Cohen Stephane Bastide David Cahen Jacqueline Libman Abraham Shanzer Yossi Rosenwaks 《Optical Materials》1998,9(1-4):394-400
Control over semiconductor surface energetics can be achieved using different chemisorbed organic molecules with diverse electronic properties. We find evidence of such control over CdTe upon adsorption of dicarboxylic acid derivatives with different substituted phenyl rings. FT-IR measurements show that the dicarboxylic acid derivatives bind as carboxylates to form approximately one monolayer. Such chemisorption modifies both the band bending and the electron affinity (up to 500 and 700 mV, respectively), as measured by contact potential difference WPM Changes in band bending result from a coupling between molecular orbitals and surface states close to the valence band and depend on the withdrawing character of the phenyl substituent. A model is presented to interpret and explain the data. 相似文献
207.
208.
Stephane Marais Yuichi Hirata Dominique Langevin Corinne Chappey Trong Q. Nguyen Michel Metayer 《Materials Research Innovations》2002,6(2):79-88
The transport of water and gases (pure oxygen and carbon dioxide) through poly(ethylene-co-vinyl acetate) (EVA) films of different
VA contents and through a low density polyethylene LDPE (used as reference with 0 wt.% VA), was analysed by permeation and
sorption measurements.
In the case of water, for EVA of 70 wt.% VA, a plasticization effect on the material was observed. For EVA of 19 wt.% VA,
there was no plasticization, while for EVA of 4.5 wt.% VA and for LDPE, the water diffusion coefficient decreases with increasing
water. An empirical law was then found to account for the reduction of the water diffusivity. A negative plasticization effect
was attributed to the formation of water clusters in these rather non polar polymers. This latter result was confirmed by
sorption measurements and infra-red spectroscopy. The increase in water sorption extent with the VA content leads to a steady
increase in the water permeability in the EVA copolymers.
In the case of gas permeation, both for O2 and CO2 and whatever the VA content of the copolymer used, the experimental curves are characterized by a constant diffusion coefficient.
This is confirmed by sorption experiments. In terms of gas permeability, EVA copolymers are characterized by low coefficients
especially for oxygen. In the EVA rubbery copolymers, The O2 solubility coefficient does not increase with the VA content due to the lack of polar interactions, while the CO2 one increases due to the overall interactions between CO2 induced dipoles and the polar the VA carbonyl groups. For these copolymers, the H2O/CO2 and H2O/O2 selectivities are very high. The experimental values of the selectivities indicate that these EVA copolymers appear as good
candidates for applications using high perm-selectivity properties.
Electronic Publication 相似文献
209.
Isabelle A.M. Worms Stephane Dubascoux Jacqueline Traber Vera I. Slaveykova 《Water research》2010,44(1):340-2510
Colloidal organic matter from wastewater treatment plants was characterized and examined with respect to its role in metal distribution by using tangential flow ultrafiltration, liquid chromatography coupled with organic carbon and UV detectors, and an asymmetrical flow field-flow fractionation (AFlFFF) multidetection platform. Results revealed that a humic-like fraction of low aromaticity with an average molar mass ranging from 1600 to 2600 Da was the main colloidal component. High molar mass fractions (HMM), with molar mass ranges between 20 and 200 kDa, were present in lower proportions. Ag, Cd, Cu, Cr, Mn and Zn were found mainly in the dissolved phase (<0.45 μm) and their distribution between colloidal and truly dissolved fractions was strongly influenced by the distribution of dissolved organic carbon. AFlFFF coupled to ICP-MS showed that Ag, Cd, Cu, Cr, Mn and Zn associate to the low molar mass fraction of the colloidal pool, whereas Al, Fe and Pb were equally bound to low and high molar mass fractions. 相似文献
210.