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281.
Orgiu E Masillamani AM Vogel JO Treossi E Kiersnowski A Kastler M Pisula W Dötz F Palermo V Samorì P 《Chemical communications (Cambridge, England)》2012,48(10):1562-1564
An enhancement in charge transport capacity in a poly(3-hexylthiophene) (P3HT) semicrystalline film, up to field-effect mobilities approaching 0.1 cm(2) V(-1) s(-1), has been achieved by co-deposition with a small molecule, i.e. 5,5'-bis(4-n-hexylphenyl)-2,2'-bithiophene (dH-PTTP), forming highly ordered crystals bridging large polymeric domains. 相似文献
282.
We address the exact resolution of a Mixed Integer Non Linear Programming model where resources can be activated in order to satisfy a demand (a covering constraint) while minimizing total cost. For each resource, there is a fixed activation cost and a variable cost, expressed by means of latency functions. We prove that this problem is ${\mathcal {N} \mathcal {P}}$ -hard even for linear latency functions. A branch and bound algorithm is devised, having two important features. First, a dual bound (equal to that obtained by continuous relaxation) can be computed very efficiently at each node of the enumeration tree. Second, to break symmetries resulting in improved efficiency, the branching scheme is n-ary (instead of binary). These features lead to a successful comparison against two popular commercial and open-source solvers, CPLEX and Bonmin. 相似文献
283.
Mativetsky JM Treossi E Orgiu E Melucci M Veronese GP Samorì P Palermo V 《Journal of the American Chemical Society》2010,132(40):14130-14136
Conductive atomic force microscopy (C-AFM) has been used to correlate the detailed structural and electrical characteristics of graphene derived from graphene oxide. Uniform large currents were measured over areas exceeding tens of micrometers in few-layer films, supporting the use of graphene as a transparent electrode material. Moreover, defects such as electrical discontinuities were easily detected. Multilayer films were found to have a higher conductivity per layer than single layers. It is also shown that a local AFM-tip-induced electrochemical reduction process can be used to pattern conductive pathways on otherwise-insulating graphene oxide. Transistors with micrometer-scale tip-reduced graphene channels that featured ambipolar transport and an 8 order of magnitude increase in current density upon reduction were successfully fabricated. 相似文献
284.
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286.
Motivated by some questions in continuum mechanics and analysis in metric spaces, we give an intrinsic characterization of sequentially weak lower semicontinuous functionals defined on Sobolev maps with values into manifolds without embedding the target into Euclidean spaces. 相似文献
287.
288.
Cavaliere E Artiglia L Barcaro G Rizzi GA Bondino F Fortunelli A Gavioli L Granozzi G 《Physical chemistry chemical physics : PCCP》2011,13(38):17171-17176
We present experimental and theoretical evidence of sequential redox processes and structural transformations occurring by increasing temperature in a metal/oxide/metal system obtained via deposition of Fe atoms onto a z'-TiO(1.25)/Pt(111) ultrathin film in UHV. The initial reduction of the z'-TiO(x) phase by Fe at room temperature is followed by Fe diffusion and partial penetration into the substrate at intermediate temperatures. This triggers the formation of a bi-component material in which mixed FeO/TiO(2) nanoislands coexist on a h-TiO(1.14) ultrathin film, notably restructured (from rectangular to hexagonal) and reduced (from Ti : O = 1 : 1.25 to 1 : 1.14) with respect to the original TiO(1.25) phase. Further heating recovers the pristine z'-TiO(x) phase while Fe completely dissolves into the substrate. 相似文献
289.
Cammarata A Emanuele A Martorana A Duca D 《The journal of physical chemistry. A》2011,115(9):1676-1685
Quantum chemical calculations have been carried out to simulate Y-doped BaCeO(3) derivatives. Hartree-Fock energy functional was used to study octahedral site environments embedded in a Pmcn orthorhombic framework, showing local arrangement characterized by Ce-O-Ce, Ce-O-Y, and Y-O-Y (Z-O-Ξ) configurations and including or not hydrogen close to the moieties encompassing those configurations. The latter are, in fact, representative of - and, in our modeling approach, were treated as - local arrangements that could be found in Y:BaCeO(3)-doped materials. The geometrical optimizations performed on the structural models and a detailed orbital analysis of these systems allowed us to confirm and deepen new interpretations, concerning experimental findings already reported in the literature. In particular, the bimodal distribution characterizing the Y-O first coordination shell, found by EXAFS analysis, could be attributed to a local clustering of Y atoms showing characteristic Y-O-Y arrangements. Moreover, the local charge analysis, characterizing the models containing or not hydrogen atoms, showed that the moving protons are able to dynamically change the properties of their near environment, in any case, leaving unaltered the global protonic conduction features of the material, irrespective of the kind of cation in a given Z-O-Ξ moiety. 相似文献
290.
Melucci M Zambianchi M Favaretto L Palermo V Treossi E Montalti M Bonacchi S Cavallini M 《Chemical communications (Cambridge, England)》2011,47(6):1689-1691
We present a new strategy to realize self-assembled monolayers (SAMs) on quartz and silicon with a multicolour fluorescence pattern starting from a single, proton sensitive oligothiophene dye exposed at a defined pH. Fine tuning of the SAMs emission color over the entire visible range, including white, is demonstrated. Finally, integration of SAMs in patterned thin layer cells (TLCs) is exploited to demonstrate cation sensing potential in real devices. 相似文献