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41.
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Guido Barone Giuseppina Castronuouvo Vittorio Elia Maria Teresa Tosto 《Journal of solution chemistry》1986,15(2):199-210
The excess enthalpies of twelve ternary aqueous solutions of alcohols or monosaccharides containing thiourea have been determined by flow microcalorimetry at 25°C. The coefficients of the virial expansion of the excess enthalpies are compared with those reported in the literature for the same ternary solutions containing urea in place of thiourea. The cross-interaction coefficients are positive for the thiourea-alcohol systems and depend on the length and branching of the alkyl chain of the alcohols. On the other hand, they are negative for the thiourea-monosaccharide systems. Thus, thiourea, as urea, can be used as a probe to reveal differences in the behavior of families of solutes characterized by the same functional groups. The results can be interpreted in terms of the relative stabilities of hydration cospheres of hydrophobic or hydrophilic solutes toward a chaotropic agent such as thiourea.Presented at the sixth Italian meeting on Calorimetry and Thermal Analysis (AICAT) held in Naples, December 4–7, 1984. 相似文献
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Frank Roschangar Jianxiu Liu Marine Dufour Vittorio Farina Azad Hossain Heewon Lee Richard Varsolona Pierre Beaulieu Chris H. Senanayake 《Tetrahedron letters》2008,49(2):363-366
A regioselective Larock approach to 3-substituted-2-pyridin-2-ylindoles from 2-alkynylpyridines and 2-iodoanilines is described herein. The unexpectedly high regioselectivity can be rationalized by a combination of steric, coordinative and electronic effects. 相似文献
47.
A variable neighborhood search for the capacitated arc routing problem with intermediate facilities 总被引:2,自引:0,他引:2
Michael Polacek Karl F. Doerner Richard F. Hartl Vittorio Maniezzo 《Journal of Heuristics》2008,14(5):405-423
The capacitated arc routing problem (CARP) focuses on servicing edges of an undirected network graph. A wide spectrum of applications
like mail delivery, waste collection or street maintenance outlines the relevance of this problem. A realistic variant of
the CARP arises from the need of intermediate facilities (IFs) to load up or unload the service vehicle and from tour length
restrictions. The proposed Variable Neighborhood Search (VNS) is a simple and robust solution technique which tackles the
basic problem as well as its extensions. The VNS shows excellent results on four different benchmark sets. Particularly, for
all 120 instances the best known solution could be found and in 71 cases a new best solution was achieved. 相似文献
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It has been shown recently that the orbit space for the (Sobolev extended) gauge group action admits a stratification into Hilbert manifolds. Here it is shown that these manifolds carry a natural weak Riemannian structure defined by a metric that corresponds to the kinetic part of the Lagrangian considered in heuristic Yang-Mills theories. 相似文献
50.
Giancarlo Masci Marco Diociaiuti Vittorio Crescenzi 《Journal of polymer science. Part A, Polymer chemistry》2008,46(14):4830-4842
Thermosensitive anionic block copolymers of sodium 2‐acrylamido‐2‐methylpropanesulfonate (AMPS) and N‐isopropylacrylamide (NIPAAM) with different block lengths were prepared by atom transfer radical polymerization (ATRP). Controlled polymerization was achieved by using ethyl 2‐chloropropionate (ECP) as initiator and CuCl/CuCl2/tris(2‐dimethylaminoethyl)amine (Me6TREN) catalytic system in DMF:water 50:50 (v/v) mixtures at 20 °C. Blocks lengths ranging from 36 to 98 repeating units were obtained. The association properties in aqueous solutions at different NaCl ionic strengths were studied as a function of temperature and polymer concentration by dynamic light scattering, fluorescence spectroscopy, and energy‐filtered transmission electron microscopy. The block copolymers with a higher pNIPAAM/pAMPS ratio formed spherical core‐shell type micelles independently of the ionic strength. The block copolymers with lower pNIPAAM/pAMPS ratio formed core‐shell type micelles at high ionic strength. Larger particles were observed at low ionic strength, which could be due to the formation of vesicles or compound micelles/micellar clusters. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4830–4842, 2008 相似文献