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排序方式: 共有629条查询结果,搜索用时 15 毫秒
1.
The influence of different referencing methods on the accuracy of δ13C value measurement of ethanol fuel by gas chromatography/combustion/isotope ratio mass spectrometry
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2.
Donato Pocar Pasqualina Trimarco Gabriella Bombieri 《Journal of heterocyclic chemistry》1998,35(3):687-692
Pyrolysis of 4-aryl-5-amino-v-triazolines affords, generally, amidines and/or benzanilides. Pyrolysis of 4-aryl-5-morpholino-v-triazolines 6 , together with the expected amidines 7 and/or aryanilides 8 , produced the morpholinopyrroles 9 . The reaction mechanism of this unusual transformation is discussed. Influence of solvent dipole moment in pyrrole formation is suggested. Pyrrole 9a [i.e. 2-(3-morpholin-4-yl-2,4-pyrrol-1-yl)-benzonitrile] has been fully characterized and its molecular structure has been determined by X-ray diffraction analysis. 相似文献
3.
M. A. Macrì C. Del Gratta L. Di Donato S. Di Luzio G. L. Romani S. Della Penna A. Pasquarelli 《Il Nuovo Cimento D》1994,16(5):425-432
Summary A preliminary study is here reported on a new potential marker for biomagnetic measurements. The marker consists of superparamagnetic
polymer microspheres which were detected in the presence of external steady magnetic fields by means of an r.f.-SQUID magnetometer.
The particles were prepared in samples differing in the concentration value and immersed in a homogeneous magnetic field of
variable intensity. A simple model was taken into account for the distribution of the microspheres in the samples, so that
the theoretical values were compared to the marker field values measured by the biomagnetic sensor. The overall sensitivity
of the experimental apparatus and the minimum concentration value of the marker were then estimated. 相似文献
4.
We consider the Abelian gauge theory related to the interaction between the solitary waves of the nonlinear Klein-Gordon equation
and the electromagnetic field. We analyze the existence of electromagnetostatic solutions and, in particular, of vortices.
Dedicated to the memory of Professor Aldo Cossu 相似文献
5.
Giancarlo Marconi Sandra Monti Francesco Manoli Stefano Ottani 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):279-282
The Induced Circular Dichroism of the complex formed by inclusion of Licochalcone-A (a powerful antimalarian of natural origin)
and β-cyclodextrin was measured and calculated. The association constant was determined by titration experiments of ICD and
fluorescence. The lowest energy conformations of the complex were obtained through docking procedures and their Circular Dichroism
was evaluated within the Tinoco framework. The geometry of the complex was found to be consistent with the main experimental
features. 相似文献
6.
The periodic unfolding method was introduced in 2002 by D. Cioranescu et al. for the study of classical periodic homogenization. In this Note, we extend this method to perforated domains introducing also a boundary unfolding operator. As an application, we study the homogenization of some elliptic problems with Robin condition on the boundary of the holes. To cite this article: D. Cioranescu et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
7.
Alessandro D' Aprano Dorina Ines Donato Antonio Carrubba Doctor in Chemistry thesis of A. Carrubba 《Journal of solution chemistry》1983,12(3):209-220
Conductance measurements are reported for LiPi, NaPi, KPi, RbPi, CsPi, Bu4NPi, Bu4NBr, Bu4NClO4, Bu4NNO3, and Bu4NBBu4 at 25°C in -butyrolactone-sulfolane mixtures. In these mixtures of solvents that are practically homomorphous, isodielectic and with comparable dipole moments, the ion pair association and ionic mobilities of large ions conform to the expectations of the primitive model. Electrolytes containing lithium or sodium ions show anomalies indicating that other factors besides shape, dipole moment, and polarizability of the solvent molecules are involved in the association and transport processes of these ions. 相似文献
8.
Guido Galliani Diego Monti Giovanna Speranza Paolo Manitto 《Tetrahedron letters》1984,25(52):6037-6040
Bilin-1,19(21H,24H)-diones interact with O2·- in DMSO giving rise to adducts showing charge-transfer character. This reaction can be reversed by addition of O2·- consuming compounds. The O2·-biliverdin dimethyl ester adduct collapses partially to 10-oxobilirubin dimethyl ester when treated with thiourea and 2-mercaptoethanol. 相似文献
9.
Giancarlo Marconi Sandra Monti Francesco Manoli Alessandra DegliEsposti Andrea Guerrini 《Helvetica chimica acta》2004,87(9):2368-2377
The circular dichroism (CD) spectra of the powerful antimalarian active principle artemisinin (ART; 1 ) from Artemisia annua, and of epiartemisinin (EPI, 2), its C(7) epimer, were studied in solution in the presence and absence of β‐cyclodextrin (β‐cd). A significant inversion of sign in the region of the second electronic transition was detected. The rotational strengths were successfully calculated within the time‐dependent density functional theory (DFT), which enabled us to establish a correlation between the molecular recognition and the biological acitivities of the two isomers. 相似文献
10.
A. D'Aprano I. D. Donato F. Pinio V. Turco Liveri 《Journal of solution chemistry》1989,18(10):949-955
A calorimetric method to evaluate, at the same time, the distribution constant and the standard enthalpy of transfer of a solute partitioned between organic phase and reversed micelles is proposed. The method was applied to the partition of methanol, 1-propanol and 1-pentanol between n-heptane and AOT reversed micelles containing water at 25°C. The results show that the distribution constant decreases as the alcohol alkyl chain length increases and that the solubilization site can change as the water content of reversed AOT micelles increases. In particular, at sufficiently high water content, methanol seems to be preferably solubilized in the aqueous pseudophase whereas 1-pentanol prefers always the palisade layer as site of solubilization.In part from Doctor in Biology thesis of F. Pinio, University of Palermo, Italy. 相似文献