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1.
《Discrete Mathematics》2022,345(5):112797
If the line graph of a graph G decomposes into Hamiltonian cycles, what is G? We answer this question for decomposition into two cycles.  相似文献   
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A Gautschi time-stepping scheme for optimal control of linear second order systems is proposed and analyzed. Convergence rates are proved and shown to be valid in numerical experiments. The temporal discretization is combined with finite element and spectral based spatial discretizations, which are compared among themselves.  相似文献   
4.
In this paper, the oscillation of a class of nonlinear even order neutral partial functional differential equations with continuous distributed delay is studied. By employing the generalized Riccati transformation and the technique of differential inequalities, some new sufficient conditions are obtained for the oscillation of the partial differential equations under Robin boundary value conditions. The results generalize some of the previous results.  相似文献   
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In this paper, we determine the structure of finite groups with a small number of real-valued irreducible Brauer characters.  相似文献   
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The cobalt substituted polyoxotungstate [Co6(H2O)2(α-B-PW9O34)2(PW6O26)]17− ( Co6 ) displays fast electron transfer (ET) kinetics to photogenerated RuIII(bpy)33+, 4 to 5 orders of magnitude faster than the corresponding ET observed for cobalt oxide nanoparticles. Mechanistic evidence has been acquired indicating that: (i) the one-electron oxidation of Co6 involves Co(II) aquo or Co(II) hydroxo groups (abbreviated as Co6(II) −OH 2 and Co6(II) −OH, respectively, whose speciation in aqueous solution is associated to a pKa of 7.6), and generates a Co(III)−OH moiety ( Co6(III) −OH), as proven by transient absorption spectroscopy; (ii) at pH>pKa, the Co6(II) −OH→RuIII(bpy)33+ ET occurs via bimolecular kinetics, with a rate constant k close to the diffusion limit and dependent on the ionic strength of the medium, consistent with reaction between charged species; (iii) at pH <pKa, the process involves Co6(II) − OH2 → Co6(III)−OH transformation and proceeds via a multiple-site, concerted proton electron transfer (CPET) where water assists the transfer of the proton, as proven by the absence of effect of buffer base concentrations on the rate of the ET and by a H/D kinetic isotope in a range of 1.2–1.4. The reactivity of water is ascribed to its organization on the surface of the polyanionic scaffold through hydrogen bond networking involving the Co(II)−OH2 group.  相似文献   
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Linear vector semi-infinite optimization deals with the simultaneous minimization of finitely many linear scalar functions subject to infinitely many linear constraints. This paper provides characterizations of the weakly efficient, efficient, properly efficient and strongly efficient points in terms of cones involving the data and Karush–Kuhn–Tucker conditions. The latter characterizations rely on different local and global constraint qualifications. The global constraint qualifications are illustrated on a collection of selected applications.  相似文献   
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We study Ginzburg–Landau equations for a complex vector order parameter Ψ=(ψ+,ψ)∈C2Ψ=(ψ+,ψ)C2. We consider symmetric vortex solutions in the plane R2R2, ψ(x)=f±(r)ein±θψ(x)=f±(r)ein±θ, with given degrees n±∈Zn±Z, and prove the existence, uniqueness, and asymptotic behavior of solutions as r→∞r. We also consider the monotonicity properties of solutions, and exhibit parameter ranges in which both vortex profiles f+f+, ff are monotone, as well as parameter regimes where one component is non-monotone. The qualitative results are obtained by means of a sub- and super-solution construction and a comparison theorem for elliptic systems.  相似文献   
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