A New Ant Colony Optimization Algorithm for the Lower Bound of Sum Coloring Problem

We consider an undirected graph G?=?(V, E), the minimum sum coloring problem (MSCP) asks to find a valid vertex coloring of G, using natural numbers (1,2,...), the aim is to minimize the total sum of colors. In this paper we are interested in the elaboration of an approximate solution for the minimum sum coloring problem (MSCP), more exactly we try to give a lower bound for MSCP by looking for a decomposition of the graph based on the metaheuristic of ant colony optimization (ACO). We test different instances to validate our approach.     

Asymptotic normality of a robust kernel estimator of the regression function for functional ergodic data: Case of an unknown scale parameter

Under a nonparametric robust regression model, we consider the problem of estimating the score function ${\psi }_x$ for a fixed x in a functional space and with unknown scale parameter. The principal aim of this work is to establish the asymptotic normality of this estimator for a stationary ergodic process without any use of traditional mixing conditions.     

Molecular docking,ADME/Tox prediction,and in vitro study of the cell growth inhibitory activity of five β-carboline alkaloids

Structural Chemistry - In a continuing effort to find new cytotoxic, antitumor, and less toxic agents from β-carbolines derivatives, using experimental and computational studies, five...     

Photodissociation of bromobenzene, dibromobenzene, and 1,3,5-tribromobenzene

Quantum chemical calculations have been performed on the ground state and several low-lying excited states of bromobenzene, ortho-, meta-, and para-dibromobenzene, and 1,3,5-tribromobenzene using high-level ab initio and hybrid density-functional methods. Experimental observations of ultrafast predissociation in these molecules are clarified from extensive theoretical information about all low-energy potential-energy curves together with symmetry arguments. The intriguing observation that o- and m-dibromobenzene have two ultrafast predissociation channels while bromobenzene, p-dibromobenzene, and 1,3,5-tribromobenzene only have one such channel is explained from the calculated potential-energy curves. These show that the lowering of point-group symmetry from C2v to Cs along the main photodissociation reaction coordinate, which only occurs in o- and m-dibromobenzene, opens up a new predissociation channel. Dynamical quantum simulations based on the calculated potential-energy curves are used to estimate the coupling strength at the intersystem crossing point in bromobenzene.     

Arsirane synthesis by reaction of sulfur ylides with diazaarsoles

N-unsubstituted diazaarsoles 4 undergo an N alkylation by reaction with sulfur ylides. N-substituted diazaarsoles 5 and 9 react with dimethylsulfoxonium ylide to give stable bicyclic arsiranes 11 and 12.     

DFT and TD-DFT calculations on thieno[2,3-b]indole-based compounds for application in organic bulk heterojunction (BHJ) solar cells

Research on Chemical Intermediates - Eight novel organic compounds with donor–π–acceptor (D–π–A) structure were designed for use as donors in organic bulk...     

Efficient Synthesis of Modified Sulfamides and Cyclosulfamides Containing Phosphonate Moieties

Abstract

The synthesis of two new series of functionalized phosphonates is described. A new entry for the synthesis of 5-phosphonoalkyl cyclosulfamides and bis(phosphonoalkyl) sulfamides starting from dihalogeno bis(amino) sulfone has been developed. These compounds have been synthesized in good yields. Triethylphosphite has been used to introduce the phosphonate moiety into sulfamides and cyclosulfamides via Arbuzov reaction.     

Photodissociation of diiodomethane in acetonitrile solution and fragment recombination into iso-diiodomethane studied with ab initio molecular dynamics simulations

Series of hydrates of the most stable glycine-H+/2H2+ in the gas phase are presented at the B3LYP level. The results show that only the amino hydrogens and hydroxyl hydrogens can be monohydrated for the glycine-H+, and the amino hydrogens are preferred. The H6(O4) of glycine-2H2+ is the best site for a water molecule to attach, i.e., the corresponding hydrate is the most stable one among its isomers. Calculations reveal that the binding energies of hydrated hydrogens decrease relative to their counterparts in the isolated glycine-H+/2H2+ complexes and they are positive values and without proton transfer except those of monohydrated glycine-2H2+ complexes with the combination modes of H3O+...(glycine-H+). The complex H3O+...(glycine-H+) is formed by the combination of a H2O molecule and one hydroxyl-site proton of glycine-2H2+, and with the proton transfer to H2O. Here the interaction between the proton of H3O+ and the glycine-H+ mainly depends on an electronic one instead of an initial covalent one of the isolated glycine-2H2+. The generation of the bond between the H3O+ and the glycine-H+ makes the energy of the complex higher than the energy sum of its two separated species (or two reactants of the complex), just like the case of M+...(glycine-H+) bond (M = Li,Na). The observation can explain satisfactorily why the combinations of both a proton and an alkali ion or two alkali ions to a glycine molecule can make the corresponding complex hold reservation energy bond(s), while the combination of two protons and a glycine in our previous work cannot [H. Ai et al., J. Chem. Phys. 117, 7593 (2002)]. For the glycine-2H2+, monohydration at the any site of its amino hydrogens can make the binding strength of any other neighboring proton (hydrogens) stronger relative to its counterpart in the isolated glycine-2H2+. Further hydration, especially at the site of either of hydroxyl hydrogens, would disfavor the reservation energy of the system.     

Courants positifs à supports dans une bande

Let T be a positive current of bidimension $(p,p)$ on ${\mathbb{C}}^n$ with support in a strip. If T is closed, S. Giret has proved that T admits a well defined lifting through a blow up with smooth center. The class of positive closed currents with bidimension $(1,1)$ in the unit bidisc ${\Delta }^2$ and with support in a strip, plays a central role in the study of the dynamics of some holomorphic maps. In this note, we prove some estimates of the trace measure of T when $d{d}^{c}T?0$, we prove in particular that if T is closed, then it is algebraic. We then prove two support theorems; the first one in the case where the degree of T is finite and the second in the case where T is positive closed and with tubular support. The latter result generalizes the case $p=n?1$ proved by M. Blel, S.K. Mimouni and G. Raby, which is also a generalization of the case when T is the current of integration on an hypersurface as proved by M.T. Togni. To cite this article: F. Elkhadhra, S.K. Mimouni, C. R. Acad. Sci. Paris, Ser. I 341 (2005).