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83.
Giovanni Dantoni 《Annali di Matematica Pura ed Applicata》1945,24(1):177-194
Sunto Si determinano le varietà algebriche di irregolarità superficialeq, contenenti involuzioni {C di irregolarità superficiale π di curve di genereq−π, e si caratterizzano le varietàV
n con un gruppo picardiano ∞p (p<n) di trasformazioni birazionali in sè. 相似文献
84.
Gianfranco Denti Scolastica Serroni Giovanni Sindona Nicola Uccella 《Journal of the American Society for Mass Spectrometry》1993,4(4):306-311
Fast-atom bombardment (FAB) mass spectrometry in the negative ionization mode enables the sputtering into the gas phase of the ruthenium complexes [Ru(2,2′-bipyridine[bpy])2(2,5-bis) (pyrydil)pyrazine[dpp])](PF6)2; [Ru(bpy)2,(2,3dpp)](PF6)2;[Ru(bpy)2,(2,3-dpp-Me)]( PF6)3; and [Ru(bpy)2(?-2,3-dpp)]2 RuCl2(PF6)4 as intact radical anions. These data, combined with those avaiiable from the positive FAB spectra allow a full characterization of the analytes. 相似文献
85.
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
86.
Bruzzone S Malvaldi M Arrighini GP Guidotti C 《The journal of physical chemistry. B》2005,109(9):3807-3812
Progress in near-field optical spectroscopy research on metal nanoparticles demands a better understanding of the role of particle-particle and tip-sample interactions. In this perspective, we investigate theoretically, at a very moderate level of sophistication, the optical behavior of simple silver nanoparticle aggregates, in terms of a formalism involving a multipolar expansion of the fields involved, along with a simplified model for the optical behavior of nanostructures previously developed. In particular, the tip-sample interaction is taken into account roughly, treating the tip as an additional, single particle, characterized by proper dielectric behavior. 相似文献
87.
Quochi F Cordella F Mura A Bongiovanni G Balzer F Rubahn HG 《The journal of physical chemistry. B》2005,109(46):21690-21693
One-dimensional light amplification in individual p-sexiphenyl nanofibers is investigated. The influence of fiber morphology on light propagation properties is studied via optical and atomic force microscopy. Isolated nanofibers are shown to yield low-threshold random laser emission in the deep blue. Model calculations of coherent light propagation in one-dimensional random media qualitatively reproduce the experimental results. Implications for photonic nanosensors are briefly discussed. 相似文献
88.
Valeria Romanucci Armando Zarrelli Annalisa Guaragna Cinzia Di Marino Giovanni Di Fabio 《Tetrahedron letters》2017,58(12):1227-1229
New phosphorylating reagents 1 and 2 were prepared in three steps from 4-hydroxybenzaldehyde. They showed good efficiency in the solid phase synthesis of 5′-phosphate monoester nucleosides. End-phosphate DNA sequence synthesis demonstrated the efficiency of the new reagents (1 and 2) according to the general procedure of automated DNA synthesis. The oxidation of P(III) to P(V) and the removal of benzyl protecting groups were achieved in a single step by treatment with a 0.02 M I2/pyridine/H2O solution. Due to this one-pot treatment, it is possible to use the phosphorylating reagents (1 and 2) for the synthesis of base-sensitive ODNs. The reagents 1 and 2 are unique among phosphorylating reagents. 相似文献
89.
The renewal of the urban waterfronts has become a major focus of attention for politicians and decision makers in the city’s management programs. The recognition of the patterns that define the waterfronts’ identity is essential to select new strategies of intervention for the environmental recovery. In order to create adequate environments for everyday life within a sustainable development, new links between human senses, human perception and design need to be created. Within this wide approach, the landscape and the soundscape play a significant role and can become a key driving force in the implementation of the changes. New techniques have to be tested to identify the sonic and visual parameters capable to explain the specificity of a waterfront. With this purpose, an artificial neural network (ANN) was developed, and the relative importance of the input variables was evaluated. The collected database was also analysed by multiple linear regression (MLR) to compare the outcomes of both models. The urban waterfront of Naples (Italy) was chosen as case study. The results obtained show that the performance of the neural network is better than the one of the linear regression (rANN = 0.949, rMLR = 0.639). The interpretation of the relative importance method is also quite satisfactory in the ANN. 相似文献
90.