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81.
Given a graph G, the Shortest Capacitated Paths Problem (SCPP) consists of determining a set of paths of least total length, linking given pairs of vertices in G, and satisfying capacity constraints on the arcs of G.We formulate the SCPP as a 0-1 linear program and study two Lagrangian relaxations for getting lower bounds on the optimal value. We then propose two heuristic methods. The first one is based on a greedy approach, while the second one is an adaptation of the tabu search meta-heuristic.  相似文献   
82.
Methodology and Computing in Applied Probability - We derive rigorously the fractional counterpart of the Feynman–Kac equation for a transport problem with trapping events characterized by...  相似文献   
83.
Let (Xk)kZ be a linear process with values in a separable Hilbert space H given by Xk=j=0(j+1)?Nεk?j for each kZ, where N:HH is a bounded, linear normal operator and (εk)kZ is a sequence of independent, identically distributed H-valued random variables with Eε0=0 and E6ε062<. We investigate the central and the functional central limit theorem for (Xk)kZ when the series of operator norms j=06(j+1)?N6op diverges. Furthermore, we show that the limit process in case of the functional central limit theorem generates an operator self-similar process.  相似文献   
84.
    
A new family of macro(bi)cyclic ligands has been designed and synthesized, with the goal of developing lanthanide labels suitable for time-resolved luminescence-based biological applications. They are constructed from diamide ( 3 ) or tetralactam ( 4 ) complexing moieties associated with an intracyclic 2,2′-bipyridine chromophore and two exocyclic carboxylic groups. The luminescence properties of their Eu3+ complexes were studied in aqueous solution. In this medium, noticeable enhancements in the lifetime and quantum yield were observed, in comparison with those of other bipyridine-based ligands considered interesting as luminescent labels. The effects of coordinated water molecules, LMCT states, and ligand triplet state energy on the nonradiative deactivation processes to the ground state were examined. According to these results and in view of the stability of these complexes in aqueous solutions, the [Eu( 3 )]+ complex may be considered as a promising luminescent bioprobe.  相似文献   
85.
    
Current methods for quantitative determination of chlormequat residues in food crops are characterized by rather low recoveries and the need for derivatization (in case of gas chromatography, GC), or by high capital investment (in case of liquid chromatography–mass spectrometry, LC–MS). We propose a cation-exchange chromatography method for the analysis of chlormequat in pears. The method is based on extraction of the target compound with 40 mM HCl, followed by centrifugation and filtration. The filtrate is directly injected into an ion chromatograph equipped with a commercially available cation-exchange column and a suppressed conductivity detection system. While the limit of detection (LOD) (0.5 mg/kg) may not be small enough to allow dietary analysis, the method meets all validation requirements and is an alternative for the existing GC and LC–MS methods in quality control.  相似文献   
86.
The electronic and transport properties of Mg(2)Si are calculated using the density-functional and semi-classical Boltzmann transport theories. A detailed comparison of the efficiency of the Perdew, Burke, and Ernzerhof (PBE) and the modified Becke-Johnson (m-BJ) exchange potentials on the prediction of these properties is presented. We show that the m-BJ potential is able to predict the Mg(2)Si thermoelectric properties with better agreement with the experimental data than the PBE potential. These findings are correlated with a small modification of the valence orbitals of the materials and the opening of the gap.  相似文献   
87.
We review the past and present theoretical and experimental situations relating to wave-particle dualism. New tests aimed at enlightening the individual behavior as awave, then as aparticle, of asingle quantum mechanical system in the same experimental run are presented. The related epistemological, philosophical, and historical backgrounds are presented in a twofold exposition taking into account thepositivistic standard Copenhagen interpretation as well as therealist de Broglian point of view.  相似文献   
88.
Fused salt-water systems extending from pure fused salt to pure water have been less studied than dilute aqueous solutions, despite their practical and theoretical importance. Even fewer studies have been made regarding the influence of the temperature upon transport properties. The present publication brings new interesting information on the viscous flow properties of the following two fused nitrate-water systems containing monovalent and divalent cations: AgNO3–TINO3–M(NO3)2–H2O where M=Ca or Cd, with the TINO3 and M(NO3)2 mole fractions in the anhydrous salt fixed at 0.436 and 0.100, respectively. The parameters in the Arrhenius, Eyring, Batschinski and the Abraham and Abraham equations are found to be well correlated with the properties of the components of the melts. The temperature effect allows a discussion to be made in terms of structural features such as holes and free volumes.  相似文献   
89.
The MeOH extract of the stem barks of Drypetes tessmanniana (Euphorbiaceae) afforded two new triterpene derivatives characterized as 3beta-O-(E)-3,5-dihydroxycinnamoyl-11-oxo-olean-12-ene and 3beta,6alpha-dihydroxylup-20(29)-ene together with seven known compounds. Their structures were established on the basis of spectral analysis.  相似文献   
90.
The interest of combining the use of carbohydrates as synthons and the use of water as the reaction medium is emphasized by briefly reviewing some examples of contributions in this field achieved in our Lyon and Orsay laboratories.  相似文献   
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