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41.
Giovanni Amelino-Camelia Leonardo Barcaroli Niccoló Loret 《International Journal of Theoretical Physics》2012,51(11):3359-3375
We investigate some aspects of relativistic classical theories with “relative locality”, in which pairs of events established to be coincident by nearby observers may be described as non-coincident by distant observers. While previous studies focused mainly on the case of longitudinal relative locality, where the effect occurs along the direction connecting the distant observer to the events, we here focus on transverse relative locality, in which instead the effect is found in a direction orthogonal to the one connecting the distant observer to the events. Our findings suggest that, at least for theories of free particles, transverse relative locality is as significant as longitudinal relative locality both conceptually and quantitatively. And we observe that “dual gravity lensing” can be viewed as one of two components of transverse relative locality. We also speculate about a type of spacetime noncommutativity for which transverse relative locality could be particularly significant. 相似文献
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Pier G. Desideri Luciano Lepri Roberto Udisti Leonardo Checchini Massimo Del Bubba Renato Cini 《International journal of environmental analytical chemistry》2013,93(3-4):331-351
Abstract Organic compounds extractable with n-hexane were identified and quantitatively determined in pack, surface and deep snow samples taken at different depths and collected at several altitudes above sea level from Antarctica during the 1993/94 Italian expedition. The comparison between the composition of organic compounds in snow and the ones in pack and sea-water samples pointed out that the three matrices substantially contain the same biogenic and anthropogenic organic compounds. The contribution of marine aerosol to organic content in the snow is confirmed by the enrichment ratios calculated for the more representative classes of identified compounds (n-alkanes, phthalates and low molecular weight alkylbenzenes). The changes in the composition of organic compounds in snow as the altitude increases seem to depend on the dimensional spectrum of the aerosol. Thus, smallest particles, richest in surfactant material, reach the highest altitudes. 相似文献
44.
Journal of High Energy Physics - For the homogeneous configuration given by the long string limit of the folded string with a spin in AdS 3 and a spin and a winding number in S 1, we solve the... 相似文献
45.
Guillaume Erbland Dr. Seifallah Abid Yohan Gisbert Nathalie Saffon-Merceron Yuichiro Hashimoto Leonardo Andreoni Théo Guérin Dr. Claire Kammerer Prof. Dr. Gwénaël Rapenne 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(71):16328-16339
The design and synthesis of two families of molecular-gear prototypes is reported, with the aim of assembling them into trains of gears on a surface and ultimately achieving controlled intermolecular gearing motion. These piano-stool ruthenium complexes incorporate a hydrotris(indazolyl)borate moiety as tripodal rotation axle and a pentaarylcyclopentadienyl ligand as star-shaped cogwheel, equipped with five teeth ranging from pseudo-1D aryl groups to large planar 2D paddles. A divergent synthetic approach was followed, starting from a pentakis(p-bromophenyl)cyclopentadienyl ruthenium(II) complex as key precursor or from its iodinated counterpart, obtained by copper-catalyzed aromatic Br/I exchange. Subsequent fivefold cross-coupling reactions with various partners allowed high structural diversity to be reached and yielded molecular-gear prototypes with aryl-, carbazole-, BODIPY- and porphyrin-derived teeth of increasing size and length. 相似文献
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Fabio Mazzotti Leonardo Di Donna Hicham Benabdelkamel Bartolo Gabriele Anna Napoli Giovanni Sindona 《Journal of mass spectrometry : JMS》2010,45(4):358-363
Pterostilbene (trans‐3,5‐dimethoxy‐4‐hydroxystilbene) is an active component found in several plant species, exhibiting important pharmacological properties. A new and reliable method of assaying this phyto compound in various matrices is presented; the assay is based on (1) the selectivity of liquid chromatography (LC) hyphenated with electrospray ionisation (ESI), (2) the specificity of a two‐step mass spectrometric analysis (MS/MS) and (3) the accuracy of the isotope dilution method. The labelled analogue may be conveniently synthesised in a few steps. The sensitivity of the method is confirmed by the very low limit of detection (LOD) and limit of quantitation (LOQ) values achieved in the assay of pterostilbene in two distinct fortified matrices, and is further supported by the observed accuracy values. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Marco Bellagamba Luigi Bencivenni Lorenzo Gontrani Leonardo Guidoni Claudia Sadun 《Structural chemistry》2013,24(3):933-943
In this work, we report a multitechnique (energy-dispersive X-ray diffraction, computational methods, and FTIR spectroscopy) study of the tautomeric equilibrium of 1,2,3-triazole, one of the few small nitrogen-containing eterocycles liquid at room temperature. The T-2H form (C 2v symmetry) is found to be strongly favored in gas and solid phases, whereas the neat liquid gives diffraction patterns that can be interpreted satisfactorily with the structure functions calculated from some molecular dynamics results for both T-2H and T-1H tautomers, although the T-2H form gives a slightly better agreement. 相似文献
50.
Leonardo M. da Costa Stanislav R. Stoyanov Raimundo N. Damasceno José Walkimar de M. Carneiro 《International journal of quantum chemistry》2013,113(24):2621-2628
Density Functional Theory (UB3LYP/6‐311++G(d,p)) calculations of the affinity of the pentaaqua nickel(II) complex for a set of phosphoryl [O?P(H)(CH3)(PhR)], imino [HN?C(CH3)(PhR)], thiocarbonyl [S?C(CH3)(PhR)] and carbonyl [O?C(CH3)(PhR)] ligands were performed, where R?NH2, OCH3, OH, CH3, H, Cl, CN, and NO2 is a substituent at the para‐position of a phenyl ring.The affinity of the pentaaqua nickel(II) complex for these ligands was analized and quantified in terms of interaction enthalpy (ΔH), Gibbs free energy (ΔG298), geometric and electronic parameters of the resultant octahedral complexes. The ΔH and ΔG298 results show that the ligand coordination strength increases in the following order: carbonyl < thiocarbonyl < imino < phosphoryl. This coordination strength order is also observed in the analysis of the metal‐ligand distances and charges on the ligand atom that interacts with the Ni(II) cation. The electronic character of the substituent R is the main parameter that affects the strength of the metal‐ligand coordination. Ligands containing electron‐donating groups (NH2, OCH3, OH) have more exothermic ΔH and ΔG298 than ligands with electron‐withdrawing groups (Cl, CN, NO2). The metal‐ligand interaction decomposed by means of the energy decomposition analysis (EDA) method shows that the electronic character of the ligand modulates all the components of the metal‐ligand interaction. The absolute softness of the free ligands is correlated with the covalent contribution to the instantaneous interaction energy calculated using the EDA method. © 2013 Wiley Periodicals, Inc. 相似文献