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991.
992.
Jean-Pierre Majoral Anne-Marie Caminade Regis Laurent Cedric-Olivier Turrin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1481-1484
The properties and applications of phosphorus-containing dendritic macromolecules in various fields, including material science and biology, are reported. 相似文献
993.
Jean-Jacques Strodiot Jean-Pierre Crouzeix Jacques A. Ferland Van Hien Nguyen 《Journal of Global Optimization》2008,42(1):121-138
In this paper, we present several new implementable methods for solving a generalized fractional program with convex data.
They are Dinkelbach-type methods where a prox-regularization term is added to avoid the numerical difficulties arising when
the solution of the problem is not unique. In these methods, at each iteration a regularized parametric problem is solved
inexactly to obtain an approximation of the optimal value of the problem. Since the parametric problem is nonsmooth and convex,
we propose to solve it by using a classical bundle method where the parameter is updated after each ‘serious step’. We mainly
study two kinds of such steps, and we prove the convergence and the rate of convergence of each of the corresponding methods.
Finally, we present some numerical experience to illustrate the behavior of the proposed algorithms, and we discuss the practical
efficiency of each one.
相似文献
994.
Marie-Laure Dano Jean-Pierre Bourque 《International Journal of Solids and Structures》2009,46(6):1305-1316
This paper presents a method to predict the through-thickness moisture content distribution and associated induced deformations of paper and cardboard sheets as they are subjected to relative humidity changes. The transient moisture diffusion problem is solved using a “natural” analytic approach that has previously been applied for solving transient heat conduction in multi-layer solids. The deformation behaviour of the sheet during the moisture diffusion process is predicted using a semi-analytical approach based on a Rayleigh–Ritz minimization of the total potential energy. Geometrically nonlinear effects are taken into account. Curvatures of the originally flat sheet are predicted as a function of time, as are the shapes of the sheet for steady-state condition. As multiple solutions exist, stability is studied. The developed model was used to study the deformation behaviour of one paper and two cardboard sheets. Comparisons with finite-element results demonstrate that the developed model provides accurate results. The displacements obtained for steady-state conditions are within +6%. Comparisons with previous steady-state analyses reveal important differences in the shape of one cardboard sheet. This suggests that the moisture diffusion process may influence the configuration assumed by the sheet at steady-state equilibrium. Hence, it may be necessary to take the moisture diffusion into account in the analysis to accurately predict the hygro-mechanical behaviour of paper or cardboard sheets. 相似文献
995.
Marie-Agnés Lacour Anne-Marie Caminade Marc Taillefer Jean-Pierre Majoral 《Tetrahedron letters》2009,50(34):4870-4873
Synthesis of unprecedented phosphorus dendrimers from generations 1 to 3 capped with functionalized phosphonium units bearing both P-C and P-N bonds is reported. 相似文献
996.
Fabien Remondiere Barbara Malič Marija Kosec Jean-Pierre Mercurio 《Journal of Sol-Gel Science and Technology》2008,46(2):117-125
Na0.5Bi0.5TiO3 (NBT) thin films were fabricated by a chemical solution deposition (CSD) method. A route involving the reaction between sodium
and bismuth acetates and titanium n-butoxide was used to synthesise the different precursor solutions. The thermal decomposition and crystallization pathways
of different modified precursors have been studied by thermal analysis and X-ray diffraction techniques. As a consequence
of the modification of the precursor solutions and their different thermal behaviour, the nucleation of the stable perovskite
phase happens at different temperatures depending on each case but is found to be at temperatures as low as 500 °C. For the
thin film processing, the drying and pyrolysis temperatures were chosen according to the thermogravimetric data to minimize
the strain resulting from the shrinkage of the film during the elimination of solvents and organic ligands. The crystallization
process was studied and the experimental results are discussed in terms of structural, microstructural and electrical features
investigated by field-emission scanning electron microscopy, atomic force microscopy in tapping and piezo-force modes and
X-ray diffraction. 相似文献
997.
Harmonic vibrational analysis for fully optimized Cs and C2v structures of C60O has been performed with AM1 quantum-chemical method. The vibrational frequencies, their (partial) symmetry classification and IR intensities are reported, and their relationships to observations discussed. 相似文献
998.
Many difficulties of interpretation met by contemporary researchers attempting to recast or generalize Dirac's, Proca's, or Maxwell's theories using biquaternions or Clifford numbers have been encountered long ago by a number of physicists including Lanczos, Proca, and Einstien. In the modern approach initiated by Gürsey, these difficulties are solved by recognizing that most generalizations lead to theories describing superpositions of particles of different intrinsic spin and isospin, so that the correct interpretation emerges from the requirement of full Poincaré covariance, including space and time reversal, as well as reversion and gauge invariance. For instance, the doubling of the number of solutions implied by the simplest generalization of Dirac's equation (i.e., Lanczos's equation) can be interpreted as isospin. In this approach, biquaternions and Clifford numbers become powerful opportunities to formulate the Standard Model of elementary particles, as well as many of its possible generalizations, in very elegant and compact ways. 相似文献
999.
We give a numerical criterion for a badly conditioned zero of a system of analytic equations to be part of a cluster of two zeros.
1000.