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41.
Diana Caponetti Espedito De Pascale Petr P. Zabreįko 《Rendiconti del Circolo Matematico di Palermo》2000,49(3):545-560
Nondifferentiable operator equations in spaces equipped with aK-norm — map taking values in the cone of an ordered Banach space — are studied. The majorant method is used to derive the convergence of a modified sequence of Newton-Kantorovich approximations. 相似文献
42.
Mbarka Mabrouki Marc Aiguier Jean-Paul Comet Pascale Le Gall Adrien Richard 《Mathematics in Computer Science》2011,5(3):263-288
In the course of understanding biological regulatory networks (BRN), scientists usually start by studying small BRNs that they believe to be of particular importance to represent a biological function, and then, embed them in a larger network. Such a reduction can lead to neglect relevant regulations and to study a network whose properties can be very different from the properties of this network viewed as a part of the whole. In this paper we study, from a logical point of view, on which conditions concerning both networks, properties can be inherited by BRNs from sub-BRNs. We give some conditions on the nature of the network embeddings ensuring that dynamic properties on the embedded sub-BRNs are preserved at the level of the whole BRN. 相似文献
43.
This paper investigates the integration of the employee timetabling and production scheduling problems. At the first level, we manage a classical employee timetabling problem. At the second level, we aim at supplying a feasible production schedule for a set of interruptible tasks with qualification requirements and time-windows. Instead of hierarchically solving these two problems as in the current practice, we try here to integrate them and propose two exact methods to solve the resulting problem. The former is based on a Benders decomposition while the latter relies on a specific decomposition and a cut generation process. The relevance of these different approaches is discussed here through experimental results. 相似文献
44.
A new optimization-based numerical method is proposed for the solution to diffusion problems with sign-changing conductivity coefficients. In contrast to existing approaches, our method does not rely on the discretization of a stabilized equation, and the convergence of the scheme can be proved without any symmetry assumption on the mesh near the interface where the conductivity sign changes. 相似文献
45.
F. Chitry S. Pellet-Rostaing A. Guy J. Foos M. Lemaire 《Journal of Radioanalytical and Nuclear Chemistry》2002,251(1):155-157
The separation of Am(III) from a mixture of lanthanides(III) was performed in aqueous medium by nanofiltration combined with a complexation step using a DTPA derivative as selective complexing agent. 相似文献
46.
Denis Veynante Benoît Fiorina Pascale Domingo Luc Vervisch 《Combustion Theory and Modelling》2013,17(6):1055-1088
Detailed chemical mechanisms have to be incorporated in turbulent combustion modelling to predict flame propagation, ignition, extinction or pollutant formation. Unfortunately, hundreds of species and thousands of elementary reactions are involved in hydrocarbon chemical schemes and cannot be handled in practical simulations, because of the related computational costs and the need to model the complexity of their interaction with turbulent motions. Detailed chemistry may be handled using look-up tables, where chemical parameters such as reaction rates and/or species mass fractions are determined from a reduced set of coordinates, progress variables or mixture fractions, as proposed in ILDM, FPI or FGM methods. Nevertheless, these tables may require large computer memory spaces and non-negligible access times. This issue becomes of crucial importance when running on massively parallel computers: to implement these databases in shared memories would induce a large number of data exchanges, reducing the overall code performance; on the other hand duplicating databases in every local processor memory may become impossible either for large databases or small local memories. This work proposes to take advantage of the self-similar behaviour of turbulent premixed flames to reduce the size of these chemical databases, specifically when running on massively parallel machines, under the FPI (Flame Prolongation of ILDM) framework. Several approaches to reduce the database are investigated and discussed both in terms of memory requirements and access times. A very good compromise is obtained for methane–air turbulent premixed flames, where the size of the database is decreased by a factor of 1000, while the access time is reduced by about 60%. 相似文献
47.
Dr. Jordan Donat Mr. Patrick Dubourdeaux Dr. Martin Clémancey Dr. Julia Rendon Clara Gervasoni Mr. Morgan Barbier Jessica Barilone Dr. Jacques Pécaut Prof. Dr. Serge Gambarelli Prof. Dr. Pascale Maldivi Prof. Dr. Jean-Marc Latour 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(70):e202201875
Nitrene transfer reactions have emerged as one of the most powerful and versatile ways to insert an amine function to various kinds of hydrocarbon substrates. However, the mechanisms of nitrene generation have not been studied in depth albeit their formation is taken for granted in most cases without definitive evidence of their occurrence. In the present work, we compare the generation of tosylimido iron species and NTs transfer from FeII and FeIII precursors where the metal is embedded in a tetracarbene macrocycle. Catalytic nitrene transfer to reference substrates (thioanisole, styrene, ethylbenzene and cyclohexane) revealed that the same active species was at play, irrespective of the ferrous versus ferric nature of the precursor. Through combination of spectroscopic (UV-visible, Mössbauer), ESI-MS and DFT studies, an FeIV tosylimido species was identified as the catalytically active species and was characterized spectroscopically and computationally. Whereas its formation from the FeII precursor was expected by a two-electron oxidative addition, its formation from an FeIII precursor was unprecedented. Thanks to a combination of spectroscopic (UV-visible, EPR, Hyscore and Mössbauer), ESI-MS and DFT studies, we found that, when starting from the FeIII precursor, an FeIII tosyliodinane adduct was formed and decomposed into an FeV tosylimido species which generated the catalytically active FeIV tosylimide through a comproportionation process with the FeIII precursor. 相似文献
48.
Given a tree each of whose terminal vertices is associated with a given point in a compact metric space, the problem is to optimally associate a point in this space to each nonterminal vertex of the tree. The optimality criterion is the minimization of the sum of the lengths, in the metric space, over all edges of the tree. This note shows how a dynamic programming solution to this problem generalizes a number of previously published algorithms in diverse metric spaces, each of which has direct and significant applications to biological systematics or evolutionary theory. 相似文献
49.
Andrianarivo Irène Rahobinirina Maonja Finaritra Rakotondramanga Alexandra Berlioz-Barbier Estelle Métay Voahangy Ramanandraibe Marc Lemaire 《Tetrahedron letters》2017,58(23):2284-2289
A unique advanced intermediate: 3-Pentadecylcyclohexanone was synthetized from the crude product which contained a mixture of cardanol, cardol and 2-methylcardol, which was hydrogenated onto Pd/C at 80 °C. From this alkylated cyclohexanone: C15 alkylated adipic acid, caprolactam, caprolactone, were synthetized in high yields, such products may have many potentially applications in polymer chemistry. The condensation of the 3-pentadecyl-cyclohexanone and triethylene glycol in oxidative or reductive conditions gave aryl ether and cyclohexyl ether, this may be a way to prepare intermediate for surfactant chemistry. Therefore we show that Cashew Nut Shell Liquid (CNSL) may lead to numerous useful compounds thank to the preparation of a unique advanced intermediate. 相似文献
50.
Gerd Finke Pierre Lemaire Jean-Marie Proth Maurice Queyranne 《European Journal of Operational Research》2009,199(3):702-705
In this paper, we present a new objective function for scheduling on parallel machines: minimizing the number of machines for schedules of minimum length. We study its complexity and we prove the NP-completeness of this problem, even if there is no precedences or for unitary execution times. We propose several polynomial algorithms for various particular cases. 相似文献