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First, this paper deals with lagrangean heuristics for the 0-1 bidimensional knapsack problem. A projected subgradient algorithm is performed for solving a lagrangean dual of the problem, to improve the convergence of the classical subgradient algorithm. Secondly, a local search is introduced to improve the lower bound on the value of the biknapsack produced by lagrangean heuristics. Thirdly, a variable fixing phase is embedded in the process. Finally, the sequence of 0-1 one-dimensional knapsack instances obtained from the algorithm are solved by using reoptimization techniques in order to reduce the total computational time effort. Computational results are presented. 相似文献
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Remarks on the asymptotic behavior of scalar auxiliary variable (SAV) schemes for gradient-like flows 下载免费PDF全文
Anass Bouchriti Morgan Pierre Nour Eddine Alaa 《Journal of Applied Analysis & Computation》2020,10(5):2198-2219
We introduce a time semi-discretization of a damped wave equation by a SAV scheme with second order accuracy. The energy dissipation law is shown to hold without any restriction on the time step. We prove that any sequence generated by the scheme converges to a steady state (up to a subsequence). We notice that the steady state equation associated to the SAV scheme is a modified version of the steady state equation associated to the damped wave equation. We show that a similar result holds for a SAV fully discrete version of the Cahn-Hilliard equation and we compare numerically the two steady state equations. 相似文献
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Majdoub Mohammed Essamlali Younes Amadine Othmane Ganetri Ikram Hafnaoui Anass Khouloud Mehdi Zahouily Mohamed 《Cellulose (London, England)》2021,28(12):7717-7734
Cellulose - A novel, environmentally friendly and simple method for chemical functionalization of microcrystalline cellulose (MCC) to produce organophilic cellulose nanocrystals (CNC-ODA) is herein... 相似文献
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N. Benayad A. Dakhama A. Klümper J. Zittartz 《Zeitschrift für Physik B Condensed Matter》1996,101(4):623-630
A theoretical study of a mixed spin-1/2 and spin-3/2 Ising system with independent transverse fields is presented using an effective field method within the framework of a single-site cluster theory. In this approach the effective field equations are derived using a probability distribution method based on the use of generalized van der Waerden identities accounting exactly for the single-site kinematic relations. The effect of the transverse fields on the critical behaviour is studied. The thermal dependence of the longitudinal and transverse components of the magnetization and its higher moments is also studied. 相似文献
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Glycosyl‐Substituted Dicarboxylates as Detergents for the Extraction,Overstabilization, and Crystallization of Membrane Proteins 下载免费PDF全文
Dr. Kim‐Anh Nguyen Dr. Marine Peuchmaur Sandrine Magnard Dr. Romain Haudecoeur Dr. Cédric Boyère Saravanan Mounien Ikram Benammar Veronica Zampieri Dr. Sébastien Igonet Dr. Vincent Chaptal Dr. Anass Jawhari Prof. Ahcène Boumendjel Dr. Pierre Falson 《Angewandte Chemie (International ed. in English)》2018,57(11):2948-2952
To tackle the problems associated with membrane protein (MP) instability in detergent solutions, we designed a series of glycosyl‐substituted dicarboxylate detergents (DCODs) in which we optimized the polar head to clamp the membrane domain by including, on one side, two carboxyl groups that form salt bridges with basic residues abundant at the membrane–cytoplasm interface of MPs and, on the other side, a sugar to form hydrogen bonds. Upon extraction, the DCODs 8 b , 8 c , and 9 b preserved the ATPase function of BmrA, an ATP‐binding cassette pump, much more efficiently than reference or recently designed detergents. The DCODs 8 a , 8 b , 8 f , 9 a , and 9 b induced thermal shifts of 20 to 29 °C for BmrA and of 13 to 21 °C for the native version of the G‐protein‐coupled adenosine receptor A2AR. Compounds 8 f and 8 g improved the diffraction resolution of BmrA crystals from 6 to 4 Å. DCODs are therefore considered to be promising and powerful tools for the structural biology of MPs. 相似文献
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Znabet A Blanken S Janssen E de Kanter FJ Helliwell M Turner NJ Ruijter E Orru RV 《Organic & biomolecular chemistry》2012,10(5):941-944
An efficient combination of MAO-N-catalyzed desymmetrization of cyclic meso-amines with Ugi-Smiles multicomponent chemistry produced optically pure N-aryl proline amides. This method represents the first report of a fully asymmetric Ugi-Smiles process. 相似文献
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Within a real-space renormalization group framework we study the three-dimensional semi-infinite mixed spin Ising model (spins =1/2 andS=1). The bilinear (K
s
) and the biquadratic (L
S
) interactions on the surface might be different from the bulk onesK
B
andL
B
. The parameter space is four dimensional. We find 26 fixed points describing a large variety of critical behaviour. The effect ofL
B
andL
S
on the surface transition is investigated.Supported by the agreement of cooperation between the DFGW. Germany and the CNR-Maroc 相似文献