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101.
New nonlinear compounds containing 1,4‐diaryl‐[1,2,3]‐triazole were prepared using a straightforward and efficient method for the regioselective synthesis of [1,2,3]‐triazoles. The methodology consists of a Cu(I)‐catalyzed 1,3‐dipolar cycloaddition of aryl azides to terminal arylacetylenes (click reaction). All compounds exhibited liquid‐crystalline profile. 相似文献
102.
Giovanni Capobianco Dajana Conte Ida Del Prete 《Journal of Computational and Applied Mathematics》2009
Non-stationary discrete time waveform relaxation methods for Abel systems of Volterra integral equations using fractional linear multistep formulae are introduced. Fully parallel discrete waveform relaxation methods having an optimal convergence rate are constructed. A significant expression of the error is proved, which allows us to estimate the number of iterations needed to satisfy a prescribed tolerance and allows us to identify the problems where the optimal methods offer the best performance. The numerical experiments confirm the theoretical expectations. 相似文献
103.
I. Pallecchi L. Pellegrino E. Bellingeri A.S. Siri D. Marré G.C. Gazzadi 《Journal of magnetism and magnetic materials》2008
In this work we analyse systematically how morphological and magnetotransport properties of manganite thin films are affected by the damage induced by focused ion beam (FIB) irradiation. We irradiate different areas of the same sample with doses ranging from 5×1012 to 3×1017 ions/cm2 and we find that the film becomes swollen for doses up to 1016 ions/cm2 and is eventually eroded by ion milling for further irradiation. On the other hand, transport properties are much more sensitive to FIB irradiation: the metal–insulator transition temperature is found to decrease monotonically with increasing doses up to 1.8×1013 ions/cm2. At doses higher than 5.6×1013 ions/cm2 the metallic state is completely suppressed and likely, also ferromagnetism. 相似文献
104.
R. Conte 《Physics letters. A》2008,372(13):2269-2270
The Bianchi IX cosmological model in vacuum can be represented by several six-dimensional dynamical systems. In one of them we present a new closed form solution expressed by a third Painlevé function. 相似文献
105.
Elena Piacenza Delia Francesca Chillura Martino Luciano Cinquanta Pellegrino Conte Paolo Lo Meo 《Magnetic resonance in chemistry : MRC》2022,60(3):369-385
A set of commercial milk and Sicilian cheeses was analysed by a combination of fast field cycling (FFC) nuclear magnetic resonance (NMR) relaxometry and chemometrics. The NMR dispersion (NMRD) curves were successfully analysed with a mathematical model applied on Parmigiano–Reggiano (PR) cheese. Regression parameters were led back to the molecular components of cheeses (water trapped in casein micelles, proteins and fats) and milk samples (water belonging to hydration shells around dispersed colloidal particles of different sizes and bulk water). The application of chemometric analysis on relaxometric data enabled differentiating milk from cheeses and revealing differences within the two sample groups of either cheeses or milk samples. Marked differences among cheeses were evidenced by statistical analysis of the sole quadrupolar peaks parameters, suggesting that these contain information on the nature of the milk used during cheese production. Hence, combination of FFC NMR and chemometrics represents a powerful tool to investigate alterations in dairy products. 相似文献
106.
Elio Conte 《Advances in Applied Clifford Algebras》2000,10(2):298-299
107.
108.
109.
Michele R. Chierotti Dr. Luca Ferrero Dr. Nadia Garino Dr. Roberto Gobetto Prof. Luca Pellegrino Dr. Dario Braga Prof. Fabrizia Grepioni Prof. Lucia Maini Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(14):4347-4358
Five new polymorphs and one hydrated form of 2‐thiobarbituric acid have been isolated and characterised by solid‐state methods. In both the crystalline form II and in the hydrate form, the 2‐thiobarbituric molecules are present in the enol form, whereas only the keto isomer is present in crystalline forms I (reported in 1967 by Calas and Martinex), III , V and VI . In form IV , on the other hand, a 50:50 ordered mixture of enol/keto molecules is present. All new forms have been characterised by single‐crystal X‐ray diffraction, 1D and 2D (1H, 13C, and 15N) solid‐state NMR spectroscopy, Raman spectroscopy and X‐ray powder diffraction at variable temperature. It has been possible to induce keto–enol conversion between the forms by mechanical methods. The role of hydrogen‐bond interactions in determining the relative stability of the polymorphs and as a driving force in the conversions has been ascertained. To the best of the authors’ knowledge, the 2‐thiobarbituric family of crystal forms represents the richest collection of examples of tautomeric polymorphism so far reported in the literature. 相似文献
110.
Alena Průšová Pellegrino Conte Jiří Kučerík Giuseppe Alonzo 《Analytical and bioanalytical chemistry》2010,397(7):3023-3028
Fast field cycling (FFC) NMR relaxometry has been used to study the conformational properties of aqueous solutions of hyaluronan
(HYA) at three concentrations in the range 10 to 25 mg mL–1. Results revealed that, irrespective of the solution concentration, three different hydration layers surround hyaluronan.
The inner layer consists of water molecules strongly retained in the proximity of the HYA surface. Because of their strong
interactions with HYA, water molecules in this inner hydration layer are subject to very slow dynamics and have the largest
correlation times. The other two hydration layers are made of water molecules which are located progressively further from
the HYA surface. As a result, decreasing correlation times caused by faster molecular motion were measured. The NMRD profiles
obtained by FFC-NMR relaxometry also showed peaks attributable to 1H–14N quadrupole interactions. Changes in intensity and position of the quadrupolar peaks in the NMRD profiles suggested that
with increasing concentration the amido group is progressively involved in the formation of weak and transient intramolecular
water bridging adjacent hyaluronan chains. In this work, FFC-NMR was used for the first time to obtain deeper insight into
HYA–water interactions and proved itself a powerful and promising tool in hyaluronan chemistry. 相似文献