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61.
Francesco Aliotta 《Journal of Molecular Structure》1991,250(2-4):291-304
A number of spectroscopic investigations are reported on aqueous solutions of CdCl2 and molten Ca(NO3)2·4H2)0 and its mixture with KNO3. The Raman probe gives evidence of the existence of two different local structures in the solutions of CdCl2: one is dominated by the solvent, the other by the solute. A competition between them exists whose equilibrium changes with concentration. Hypersonic and ultrasonic velocity data and hypersonic absorption results on the same system, as a function of concentration and of temperature, give evidence of a structural relaxation connected to the local variation of the structural arrangement induced by the solute. Extended X-ray absorption fine structure (EXAFS) measurements on Ca(NO3)2·4H2O and its mixture with KNO3 reveal an inner shell of water complexation for the Ca2+ and K+ ions that produces a close-packed structure in which hydration forces are mainly responsible for the local arrangement. Mandelstamm-Brillouin scattering results give evidence for a relaxation phenomenon to which both structural and shear mechanisms contribute. The mean relaxation time τr, and the relaxation modulus Mr show a non-Arrhenius behaviour, supporting the idea that our systems can be regarded as fragile liquids. 相似文献
62.
PI3Kα controls several cellular processes and its aberrant signalling is implicated in tumorigenesis. One of its hotspot mutations, E545K, increases PI3Kα lipid kinase activity, but its mode of action is only partially understood. Here, we perform biased and unbiased molecular dynamics simulations of PI3Kα and uncover, for the first time, the free energy landscape of the E545K PI3Kα mutant. We reveal the mechanism by which E545K leads to PI3Kα activation in atomic-level detail, which is considerably more complex than previously thought.The mechanism by which the cancer-causing E545K mutation may lead to PI3Kα activation is described in atomic-level detail. 相似文献
63.
The apparent molar volumes V of KCl, BaCl2, K2SO4, LaCl3, Co(en)3Cl3 [Tris(ethylenediamine)cobalt(III) chloride], K3Co(CN)6, K3Fe(CN)6, K4Fe(CN)6, and Ba3[Co(CN)6]2 have been determined at 25°C in both light and heavy water. The V values in D2O are systematically lower and increase more rapidly with salt concentration than the V in H2O. The volume of transfer from H2O to D2O as well as the partial molar volume at infinite dilution in both solvents have also been calculated. These results together with literature values for other electrolytes were used to estimate both of these quantities for D2O solutions of individual ions. The predictions of ion hydration models and ion-ion interactions are compared with experimental observations. 相似文献
64.
The reaction of some primary amines with the methyl 2-[(α-oxobenzyl)-(α-bromo)methyl]phenylacetate ( 5 ) afforded the isoquinolinones 7a-d , which in turn were hydrogenated to 10a-d . The synthesis of these compounds was designed on the basis of a potential depressant and antiinflammatory activity found in other structurally related compounds. 相似文献
65.
A convenient route to new 3-quinolinonyl-pyrazoles and isoxazoles is described through cyclization of 3-[(E)-3-(dimethylamino)-2-propenoyl]-4-hydroxy-1-methyl-2(1H)-quinolinone. The phototoxicity as well as the cytotoxic activities of the title compounds are evaluated against leukemia- and adenocarcinoma-derived cell lines in comparison to the normal human keratinocytes. 相似文献
66.
Carlo Bruno Eleonora Ussano Gianni Barucca Davide Vanossi Giovanni Valenti Edward A. Jackson Andrea Goldoni Lucio Litti Simona Fermani Luca Pasquali Moreno Meneghetti Claudio Fontanesi Lawrence T. Scott Francesco Paolucci Massimo Marcaccio 《Chemical science》2021,12(23):8048
The presence of non-hexagonal rings in the honeycomb carbon arrangement of graphene produces rippled graphene layers with valuable chemical and physical properties. In principle, a bottom-up approach to introducing distortion from planarity of a graphene sheet can be achieved by careful insertion of curved polyaromatic hydrocarbons during the growth of the lattice. Corannulene, the archetype of such non-planar polyaromatic hydrocarbons, can act as an ideal wrinkling motif in 2D carbon nanostructures. Herein we report an electrochemical bottom-up method to obtain egg-box shaped nanographene structures through a polycondensation of corannulene that produces a new conducting layered material. Characterization of this new polymeric material by electrochemistry, spectroscopy, electron microscopy (SEM and TEM), scanning probe microscopy, and laser desorption-ionization time of flight mass spectrometry provides strong evidence that the anodic polymerization of corannulene, combined with electrochemically induced oxidative cyclodehydrogenations (Scholl reactions), leads to polycorannulene with a wavy graphene-like structure.A bottom-up synthesis of wavy graphene structures obtained through an anodic polymerization process, combined with an electrochemically triggered oxidative cyclodehydrogenation, of the bowl-shaped polyaromatic hydrocarbon corannulene. 相似文献
67.
Giovannelli Tommaso Liuzzi Giampaolo Lucidi Stefano Rinaldi Francesco 《Computational Optimization and Applications》2022,82(2):293-327
Computational Optimization and Applications - In this paper, mixed-integer nonsmooth constrained optimization problems are considered, where objective/constraint functions are available only as the... 相似文献
68.
Francesco Cubadda 《Russian Chemical Bulletin》1995,44(2):388-390
Information Congresses, Conferences, Symposia, Workshops, and Seminars in the Field of Chemical Sciences held with Participation of the Russian Academy of Sciences
The XXXV International IUPAC Symposium on macromolecular chemistry (MACROACRON-94) 相似文献69.
70.
The three-component ionic microemulsion system consisting of AOT/water/decane shows an unusual phase behavior in the vicinity
of room temperature. The phase diagram in the temperature-volume fraction (of the dispersed phase) plane exhibits a lower
consolute critical point at about 40 degrees centigrades and 10% volume fraction. A percolation line, starting from the vicinity
of the critical point, cuts across the plane, extending to high volume fraction side at progressively lower temperatures.
In this paper we review the evidence that allows to interpret the phase behavior of our system in terms of interacting spherical
droplets. We also investigate the dynamics of droplets, below and approaching the critical point by dynamic light scattering.
The first cumulant and time evolution of the droplet density correlation function can be quantitatively calculated by assuming
the existence of polydispersed fractal clusters formed by the microemulsion droplets due to attraction. The relaxation phenomena
observed in an extensive set of measurements of electrical conductivity and permittivity close to percolation is also reviewed
and interpreted through the same cluster-forming mechanism, which reproduces the most relevant features of the frequency-dependent
complex dielectric constant of this system.
Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994. 相似文献