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101.
102.
Robust branch-cut-and-price for the Capacitated Minimum Spanning Tree problem over a large extended formulation 总被引:1,自引:0,他引:1
Eduardo Uchoa Ricardo Fukasawa Jens Lysgaard Artur Pessoa Marcus Poggi de Aragão Diogo Andrade 《Mathematical Programming》2008,112(2):443-472
This paper presents a robust branch-cut-and-price algorithm for the Capacitated Minimum Spanning Tree Problem (CMST). The
variables are associated to q-arbs, a structure that arises from a relaxation of the capacitated prize-collecting arborescence problem in order to make
it solvable in pseudo-polynomial time. Traditional inequalities over the arc formulation, like Capacity Cuts, are also used.
Moreover, a novel feature is introduced in such kind of algorithms: powerful new cuts expressed over a very large set of variables
are added, without increasing the complexity of the pricing subproblem or the size of the LPs that are actually solved. Computational
results on benchmark instances from the OR-Library show very significant improvements over previous algorithms. Several open
instances could be solved to optimality. 相似文献
103.
The aim of this paper is to present the behaviour of the poly(vinyl alcohol) hydrogels [PVA-HG] in sodium and potassium chlorides aqueous solutions, due to their interactions. The tested [PVA-HG]-s have been obtained by repeated freezing and thawing cycles. White, heterogeneous hydrogels have been obtained. These hydrogels exhibit a mechanical active behaviour at their contact with electrolytes aqueous solutions, manifested by important changing in mass, volume and density of the hydrogel samples. These modifications could be explained by water elimination from the hydrogels that initially reached the equilibrium of swelling. The kinetic of the water desorption and the reversibility of this process, have been studied and some of the factors that influence this behaviour have been evidenced. The sensitivity of PVA hydrogels to electrolyte nature and concentration could be used in sensors design and also could explain some aspects of electrolytes diffusion through PVA membranes and targeted drugs delivery. 相似文献
104.
We prove an elementary formula about the average expansion of certain products of 2 by 2 matrices. This permits us to quickly
re-obtain an inequality by M. Herman and a theorem by Dedieu and Shub, both concerning Lyapunov exponents. Indeed, we show
that equality holds in Herman’s result. Finally, we give a result about the growth of the spectral radius of products.
Financial support from Pronex-Dynamical Systems, CNPq 001/2000 and from Faperj is gratefully acknowledged. 相似文献
105.
Artur MichalakMarek Nawrocki 《Indagationes Mathematicae》2002,13(2):185-195
In the paper we describe the Banach envelopes of Hardy spaces of analytic functions of several variables on polydiscs taking values in quasi-Banach spaces. 相似文献
106.
107.
Controlled Light‐Mediated Preparation of Gold Nanoparticles by a Norrish Type I Reaction of Photoactive Polymers 下载免费PDF全文
Florian Mäsing Dr. Artur Mardyukov Carsten Doerenkamp Prof. Dr. Hellmut Eckert Ursula Malkus Harald Nüsse Prof. Dr. Jürgen Klingauf Prof. Dr. Armido Studer 《Angewandte Chemie (International ed. in English)》2015,54(43):12612-12617
Gold nanoparticles (AuNPs) are subjects of broad interest in scientific community due to their promising physicochemical properties. Herein we report the facile and controlled light‐mediated preparation of gold nanoparticles through a Norrish type I reaction of photoactive polymers. These carefully designed polymers act as reagents for the photochemical reduction of gold ions, as well as stabilizers for the in situ generated AuNPs. Manipulating the length and composition of the photoactive polymers allows for control of AuNP size. Nanoparticle diameter can be controlled from 1.5 nm to 9.6 nm. 相似文献
108.
Surface Trapping and STM Observation of Conformational Isomers of a Bis(Terpyridine) Ligand from Metallosupramolecular Grids 下载免费PDF全文
Sujoy Karan Dr. Christian Hamann Dr. Hao Tang Dr. Artur R. Stefankiewicz Prof. Jean‐Marie Lehn Prof. Richard Berndt 《Chemphyschem》2015,16(7):1370-1373
Tetranuclear Co‐grid complexes incorporating bis‐tridentate ligands, namely 4,6‐bis(2,2′‐bipyrid‐6‐yl)‐2‐phenylpyrimidine, were electrosprayed onto a Au(111) substrate under an ultrahigh vacuum. Fragmentation occurs leaving the ligands in four different conformations. Most ligands are found to form H‐bonded dimers. The most abundant conformer of the ligand on the Au surface is an asymmetric form, which has not been observed before. The present results indicate that the fragmentation of coordination compounds during the deposition process, in principle, allows for surface trapping, identification, and investigation of high energy, out‐of‐equilibrium conformations of the ligand molecules at low temperatures, which otherwise would not be observable. 相似文献
109.
Inside Back Cover: Surface Trapping and STM Observation of Conformational Isomers of a Bis(Terpyridine) Ligand from Metallosupramolecular Grids (ChemPhysChem 7/2015) 下载免费PDF全文
110.
Artur Vashurin Vladimir Maizlish Ilya Kuzmin Oleg Petrov Mikhail Razumov Svetlana Pukhovskaya Oleg Golubchikov Oscar Koifman 《Journal of inclusion phenomena and macrocyclic chemistry》2017,87(1-2):37-43
The influence of the size of conjugated π-system on catalytic activity of cobalt complex with β-octaphenylporphyrin and its tetraaza-, tetrabenzo and tetrabenzotetraaza derivatives was studied in present work. It is found that catalytic activity for oxidation of sulfur-containing compounds increases under extension of conjugated macrocycle system according to the following series CoP < CoBP ≤ CoPz < CoPPz ? CoPc. 相似文献