排序方式: 共有91条查询结果,搜索用时 10 毫秒
61.
3-Deazacanthin-4-one and nine analogues, including the 8-aza analogue, were prepared rapidly and in high yields from 8-iodoquinolones and 2-chloro(het)arylboronic acids. The strategy involves construction of the central B ring via concomitant Pd-catalyzed Suzuki-Miyaura CC and Cu-catalyzed Buchwald-Hartwig CN coupling reactions. 相似文献
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We show that thin film star-shaped macromolecules exhibit significant differences in their average vitrification behavior, in both magnitude and thickness dependence, from their linear analogs. This behavior is dictated by a combination of their functionality and arm length. Additionally, the glass transition temperature at the free surface of a star-shaped molecule film may be higher than that of the interior, in contrast to their linear analogs where the opposite is true. These findings have implications for other properties, due largely to the origins, entropic, of this behavior. 相似文献
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An electric-field-assisted method to produce diffractive optical devices is demonstrated. A uniform film of liquid UV curable resin was produced as a drying ring from an organic solvent. Dielectrophoresis forces maintained the stability of the thin film and also imprinted a periodic corrugation deformation of pitch 20 μm on the film surface. Continuous in situ voltage-controlled adjustment of the optical diffraction pattern was carried out simultaneously with UV curing. A fully cured solid phase grating was produced with the particular voltage-selected tailored optical property that the zero transmitted order was suppressed for laser light at 633 nm. 相似文献
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Ioannis Emmanouil 《K-Theory》1996,10(2):197-214
In this paper, we introduce a Z-graded variant of the periodic cyclic homology of associative algebras which generalizes the infinitesimal cohomology of affine algebras in characteristic 0 and show that it satisfies the Künneth formula (i.e. it commutes with the formation of tensor products). We also show that the Künneth formula in periodic cyclic homology holds only under the presence of certain finiteness conditions. 相似文献
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Emmanouil Milakis 《Advances in Mathematics》2008,217(3):1301-1312
We study the regularity of the solution to a fully nonlinear version of the thin obstacle problem. In particular we prove that the solution is C1,α for some small α>0. This extends a result of Luis Caffarelli of 1979. Our proof relies on new estimates up to the boundary for fully nonlinear equations with Neumann boundary data, developed recently by the authors. 相似文献
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Emmanouil E. Zachariadis Christos D. Tarantilis Chris T. Kiranoudis 《European Journal of Operational Research》2013
This article introduces and solves a new rich routing problem integrated with practical operational constraints. The problem examined calls for the determination of the optimal routes for a vehicle fleet to satisfy a mix of two different request types. Firstly, vehicles must transport three-dimensional, rectangular and stackable boxes from a depot to a set of predetermined customers. In addition, vehicles must also transfer products between pairs of pick-up and delivery locations. Service of both request types is subject to hard time window constraints. In addition, feasible palletization patterns must be identified for the transported products. A practical application of the problem arises in the transportation systems of chain stores, where vehicles replenish the retail points by delivering products stored at a central depot, while they are also responsible for transferring stock between pairs of the retailer network. To solve this very complex combinatorial optimization problem, our major objective was to develop an efficient methodology whose required computational effort is kept within reasonable limits. To this end, we propose a local search-based framework for optimizing vehicle routes, in which feasible loading arrangements are identified via a simple-structured packing heuristic. The algorithmic framework is enhanced with various memory components which store and retrieve useful information gathered through the search process, in order to avoid any duplicate unnecessary calculations. The proposed solution approach is assessed on newly introduced benchmark instances. 相似文献
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A full-vector finite-element beam propagation method in 3-D is introduced for the simulation of light propagation in liquid
crystal (LC) devices. The three electric field components are expressed in terms of mixed finite elements, providing the correct
enforcement of boundary conditions. Moreover, the optical dielectric tensor of the medium can have all its nine elements nonzero,
thus allowing the LC director to have an arbitrary orientation. A photonic crystal fiber with a LC infiltrated core and a
homeotropic to multi-domain cell are analyzed. Comparison with other existing simulation techniques is provided, in order
to validate the accuracy of the proposed method. 相似文献