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101.
We study the excitation of axial quasi-normal modes of deformed non-rotating black holes by test particles and we compare the associated gravitational wave signal with that expected in general relativity from a Schwarzschild black hole. Deviations from standard predictions are quantified by an effective deformation parameter, which takes into account deviations from both the Schwarzschild metric and the Einstein equations. We show that, at least in the case of non-rotating black holes, it is possible to test the metric around the compact object, in the sense that the measurement of the gravitational wave spectrum can constrain possible deviations from the Schwarzschild solution. 相似文献
102.
Z. Halász Cosimo Binda und P. E. Alessandri 《Fresenius' Journal of Analytical Chemistry》1904,43(5):329-330
Ohne Zusammenfassung 相似文献
103.
Roberto Grisorio Claudia Piliego Pinalysa Cosma Paola Fini Piero Mastrorilli Giuseppe Gigli Gian Paolo Suranna Cosimo Francesco Nobile 《Journal of polymer science. Part A, Polymer chemistry》2009,47(8):2093-2104
The synthesis of new random poly(arylene‐vinylene)s containing the electron withdrawing 3,7‐dibenzothiophene‐5,5‐dioxide unit was achieved by the Suzuki–Heck cascade polymerization reaction. The properties of poly[9,9‐bis(2‐ethylhexyl)‐2,7‐fluorenylene‐vinylene‐co‐3,7‐dibenzothiophene‐5,5‐dioxide‐vinylene] (50/50 mol/mol, P1 ) and poly[1,4‐bis(2‐ethylhexyloxy)‐2,5‐phenylene‐vinylene‐co‐3,7‐dibenzothiophene‐5,5‐dioxide‐vinylene] (50/50 mol/mol, P2 ) were compared with those of terpolymers obtained by combining the fluorene, dibenzothiophene, and 1,4‐bis(2‐ethylexyloxy)benzene in 20/40/40 ( P3 ), 50/25/25 ( P4 ), and 80/10/10 ( P5 ) molar ratios. The polymers were characterized by 1H NMR and IR, whereas their thermal properties were investigated by TGA and DSC. Polymers P1–5 are blue–green emitters in solution (λem between 481 and 521 nm) whereas a profound red shift observed in the solid state is emission (λem from 578 to 608 nm) that can be attributed both to the charge transfer stabilization exerted by the polar medium and to intermolecular interactions occurring in the solid state. Cyclic voltammetry permitted the evaluation of the ionization potentials and also revealed a quasi‐reversible behavior in the reduction scans for the polymers ( P1–4 ) containing the higher amounts of 3,7‐dibenzothiophene‐5,5‐dioxide units. Electroluminescent devices with both ITO/PEDOT‐PSS/ P1–5 /Ca/Al (Type I) and ITO/PEDOT‐PSS/ P1–5 /Alq3/Ca/Al (Type II) configuration were fabricated showing a yellow to yellow–green emission. In the case of P4 , a luminance of 1835 cd/m2 and an efficiency of 0.25 cd/A at 14 V were obtained for the Type II devices. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2093–2104, 2009 相似文献
104.
Alessandro Pezzella Veronica Ambrogi Marianna Arzillo Alessandra Napolitano Cosimo Carfagna Marco D’Ischia 《Photochemistry and photobiology》2010,86(3):533-537
The determinants of the broadband absorption spectrum of eumelanins are still largely unknown. Herein we report a novel approach to investigate eumelanin chromophore which is based on the biomimetic oxidation of the key monomer precursor, 5,6-dihydroxyindole (DHI, 1 ), with peroxidase/hydrogen peroxide in phosphate buffer, pH 7, containing 1–5% polyvinylalcohol (PVA, 27 000 Da). This approach relies on the discovery that as low as 1% PVA can prevent precipitation of the growing melanin polymer thus allowing investigation of the chromophoric phases accompanying oxidation of DHI without confounding scattering effects. Spectrophotometric monitoring showed the initial development of a band around 530 nm persisting for about 1 h before gradually changing into the typical broadband spectrum of eumelanin. Reductive treatment caused a significant absorbance decrease in the visible region without affecting an absorption band around 320 nm. Initial product analysis indicated an altered formation ratio of 2,4′-biindolyl ( 2 ) and 2,7′-biindolyl ( 3 ) relative to control experiments. Overall, these results demonstrate for the first time that the development in solution of visible chromophores since the early oligomer stages is independent of strong aggregation/precipitation phenomena. 相似文献
105.
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107.
Cosimo Cardellicchio Maria Annunziata M. Capozzi Francesco Naso 《Tetrahedron: Asymmetry》2010,21(5):507-517
The multicomponent reaction between 2-naphthol, aryl aldehydes and ammonia or amines yields aminobenzylnaphthols in a process known as the Betti reaction, which was first uncovered at the beginning of the 20th century. The aminobenzylnaphthols could be easily resolved into their enantiomers. After a long silence, the results of our research a decade ago on this useful reaction and on the chiral materials produced has stimulated further work in a number of other laboratories. As a result, novel applications of the Betti reaction to produce new chiral aminobenzylnaphthols were reported together with the evaluation of these chiral bases in asymmetric synthesis. Herein, we present a selection of the relevant studies on this topic. 相似文献
108.
Giuseppe Romanazzi Piero Mastrorilli Ahlam Sibaouih Timo Repo Gian Paolo Suranna Cosimo Francesco Nobile 《Tetrahedron》2009,65(47):9833-355
A series of soluble quaterthiophenes (4Ta-g) bearing ester groups in the α,ω-terminal positions separated from the quaterthiophene core by ethylene (4Ta-c), vinylene (4Td-f) or ethynylene (4Tg) spacers was synthesized by means of a Pd-catalyzed homocoupling of bithiophenes proceeding via C-H bond activation. The synthetic approach gave satisfying yields of 4Ta-f but resulted in only 3% yield of 4Tg due to the competitive hydrofluorination of the triple bond. The quaterthiophenes 4Ta-g were characterized by NMR, FTIR, UV-vis, PL spectroscopies, HRMS, TGA and CV. Thin-films of 4Ta-g were deposited either by spin-coating or by thermal evaporation on Si/SiO2 for the fabrication of top-contact OTFTs. The devices prepared using 4Ta-c bearing the ester functional group separated from the quaterthiophene core by an ethylene spacer showed average hole field-effect mobility up to 2.7×10−3 cm2 V−1 s−1 and up to 6×10−3 cm2 V−1 s−1 for solution processed and for thermally evaporated OTFTs, respectively. The remarkably high solubility of 4Ta-c, along with their respectable performances in OTFTs render these molecules promising for practical applications as active layers in chemically-sensitive devices. 相似文献
109.
Benzyl p-bromophenyl sulfoxide 1 was obtained on a multigram scale and in an enantiomerically pure form by an enantioselective catalytic oxidation, using tert-butyl hydroperoxide in the presence of chiral titanium complexes. Some mechanistic and stereochemical features of interest were studied in this process. Compound 1 was then subjected to two different substitution reactions with Grignard reagents, which caused two sequentially stereocontrolled carbon-for-carbon displacements, leading to chiral nonracemic dialkyl sulfoxides. 相似文献
110.