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31.
The generalized Stirling numbers introduced recently (Mansour and Schork, 2011 [5], Mansour et al., 2011 [6]) are considered in detail for the particular case corresponding to the meromorphic Weyl algebra. A combinatorial interpretation in terms of perfect matchings is given for these meromorphic Stirling numbers and the connection to Bessel functions is discussed. Furthermore, two related -polynomial identities are derived. 相似文献
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In this paper, we study the two-staged two-dimensional fixed-orientation cutting problem. We investigate the use of the parallel
beam search algorithm for approximately solving the problem. The beam-search can be viewed as a truncated tree-search in which
a subset of generated nodes are investigated. The proposed approach tries to explore some of these nodes in parallel by applying
a master-slave paradigm. The master processor serves to guide the search-resolution by using a best-first search strategy
for selecting the successive sets of nodes, called elite nodes. Whereas each slave processor develops the search tree and
updates the global list of the master processor in an asynchronous manner. Each processor is based on combining a partial
lower bound and a complementary upper bound, obtained by solving a series of bounded knapsack problems. The proposed method
is analyzed computationally on a set of benchmark instances of the literature and their results are compared to those provided
by existing algorithms. Encouraging and new results have been obtained. 相似文献
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H. Toufik S. M. Bouzzine O. Ninis F. Lamchouri M. Aberkane M. Hamidi M. Bouachrine 《Research on Chemical Intermediates》2012,38(7):1375-1388
In this work, we investigate oligopyrroles and derivatives, which serve as models for corresponding polymers. In order to discuss these materials, we carried out DFT calculations and used DFT methods to calculate ground state electronic structures. We are particularly interested in exploring the potential of several substituent groups as electron donors with numerous ties to electronic materials by exploring and comparing the energies of HOMO, LUMO, Gap energies, and structural properties. Results are discussed in comparison with the properties of the doped oligomers. The theoretical ground-state geometry and electronic structure of the studied molecules were obtained by the DFT method at B3LYP level with 6-31G(d) basis set. The opto-electronic properties of these materials were determined by ZINDO/s and TD//B3LYP/6-31G(d) calculations performed on the B3LYP/6-31(d) optimized geometries. The results of this study demonstrate how electronic properties can be tuned by the backbone ring or side group and suggest these compounds as good candidates for opto-electronic applications. 相似文献
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This paper presents an experimental study of flow development and structure on a separated jet burner in reacting and non-reacting
flows. Effects of deflection jets in an aligned configuration of three round jets are emphasized. The idea is based on the
confinement of a central jet of fuel by two side jets of oxygen to improve mixing, to control flame stability, and to reduce
pollutant emissions. The fields of mean velocity and fluctuation intensity were measured using Particle Image Velocimetry.
The deflection of jets has a considerable effect on the dynamic behavior and on the flame characteristics. Results showed
that the deflection of jets favors mixing and accelerates merging and combining of jets to a single one. Measurements in reacting
flow showed a high influence of combustion on dynamic fields. Compared to non-reactive case, in combustion, larger radial
expansion and higher velocity were observed, particularly, above the stabilization point of the flame. 相似文献
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Lazrak Malak Toufik Hamid Bouzzine Si Mohamed Lamchouri Fatima 《Research on Chemical Intermediates》2020,46(8):3961-3978
Research on Chemical Intermediates - In this work, a series of six organic dyes-sensitized solar cells (DSSCs) combining various π-bridges with a fixed donor (triphenylamine) and a fixed... 相似文献
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Benkhedda Mohammed Boufendi Toufik Tayebi Tahar Chamkha Ali J. 《Journal of Thermal Analysis and Calorimetry》2020,139(1):411-426
Journal of Thermal Analysis and Calorimetry - In the present paper, the first and second laws of thermodynamics are utilized to select the optimized position of porous insert to achieve maximum... 相似文献
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Toufik Mansour 《Discrete Applied Mathematics》2007,155(11):1430-1440
Baxter studied a particular class of permutations by considering fixed points of the composite of commuting functions. This class is called Baxter permutations. In this paper we investigate the number of 123-avoiding Baxter permutations of length n that also avoid (or contain a prescribed number of occurrences of) another certain pattern of length k. In several interesting cases the generating function depends only on k and is expressed via the generating function for the Padovan numbers. 相似文献