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81.
Goos-H?nchen (GH) and Imbert-Fedorov (IF) shifts are diffractive corrections to geometric optics that have been extensively studied for a Gaussian beam that is reflected or transmitted by a dielectric interface. Propagating in free space before and after reflection or transmission, such a Gaussian beam spreads due to diffraction. We address here the question of how the GH and IF shifts behave for a "nondiffracting" Bessel beam. 相似文献
82.
William Aiello S.Raj Rajagopalan Ramarathnam Venkatesan 《Journal of Algorithms in Cognition, Informatics and Logic》1998,29(2):358-389
We present a construction for a family of pseudo-random generators that are very fast in practice, yet possess provable statistical and cryptographic unpredictability properties. Such generators are useful for simulations, randomized algorithms, and cryptography.Our starting point is a slow but high quality generator whose use can be mostly confined to a preprocessing step. We give a method of stretching its outputs that yields a faster generator. The fast generator offers smooth memory–time–security trade-offs and also has many desired properties that are provable. The slow generator can be based on strong one-way permutations or block ciphers. Our implementation based on the block cipher DES is faster than popular generators. 相似文献
83.
84.
Crispini A Aiello I La Deda M De Franco I Amati M Lelj F Ghedini M 《Dalton transactions (Cambridge, England : 2003)》2006,(43):5124-5134
This paper reports the synthesis, characterization, photophysical and structural properties of the homologous series of good emitting pentacoordinated GaQ'2L complexes 1-3, where Q' is 2-methyl-quinolin-8-olate and L is a phenolate substituted in para position with respect to the oxygen donor atom. A combined approach between the experimental structural analysis (i.e. the molecular fragments involved in intermolecular pi-pi interactions) and the computational study (i.e. the nature of the molecular orbitals residing therein) is discussed in order to compare the charge transport aptitude of complexes 1-3, in relation to the facing of their LUMO/LUMO, HOMO/HOMO and HOMO/LUMO arising from the molecular packing. The different phenolate ligands significantly change the packing characteristics of 1-3, with indirect effects on the electron hopping kinetics responsible for conduction in amorphous thin films. The observed preference for pyridyl-pyridyl stacking proves a faster electron conduction in comparison to hole conduction in the three complexes studied. 相似文献
85.
We present a theoretical study of multimode scattering of light by optically random media, using the Mueller-Stokes formalism which permits us to encode all the polarization properties of the scattering medium in a real 4 x 4 matrix. From this matrix two relevant parameters can be extracted: the depolarizing power D(M) and the polarization entropy E(M) of the scattering medium. By studying the relation between E(M) and D(M), we find that all scattering media must satisfy some universal constraints. These constraints apply to both classical and quantum scattering processes. The results obtained here may be especially relevant for quantum communication applications, where depolarization is synonymous with decoherence. 相似文献
86.
Aiello A Carbonelli S Esposito G Fattorusso E Iuvone T Menna M 《Organic letters》2001,3(19):2941-2944
A unique cytotoxic metabolite, turbinamide (1), has been isolated from the marine tunicate Sidnyum turbinatum through a bioassay-guided approach. Its structure has been elucidated by an extensive spectroscopic analysis. Turbinamide demonstrated a strong and selective cytotoxic effect against neuronal cells rather than immune system cells. Structure: see text. 相似文献
87.
The time behavior of the 3000 Å luminescence signals of KCl: Tl crystals is complex. Three different components can be resolved in the temperature range investigated (80–340K). These results that are typical for the Ax emission of phosphors like Kl:Tl+ and KCl:Pb2+, cannot be explained with the available theoretical models for KCl:Tl system. 相似文献
88.
89.
Covalently assembled resorcin[4]arenes and molecular tweezers: a chiral recognition rationale by NMR
Gloria Uccello Barretta Federica Balzano Federica Aiello Francesca Nardelli Alessia Ciogli Andrea Calcaterra 《Supramolecular chemistry》2016,28(7-8):647-655
Chiral diamides and tetramidic resorcin[4]arenes deriving from (R,R)-1,2-diaminocyclohexane and (S,S)-1,2-diphenylethylendiamine, and a valine containing resorcin[4]arene have been compared by NMR in the enantiodiscrimination of mandelic acid. The relevance of cooperation between side arms and external surface of resorcin[4]arene core has been ascertained. 相似文献
90.
Girolamo Cirrincione Anna Maria Almerico Patrizia Diana Paola Barraja Francesco Mingoia Stefania Grimaudo Gaetano Dattolo Enrico Aiello 《Journal of heterocyclic chemistry》1996,33(1):161-168
The behaviour of 2- and 3-aminopyrroles towards protonation is similar. In dimethyl sulphoxide/trifluoroacetic acid they are protonated at the exocyclic nitrogen, whereas in pure trifluoroacetic acid, protonation at the 5- and/or 3-position of the ring takes place. 相似文献