Search results for "nimi"
showing 10 items of 596 documents
CCDC 835276: Experimental Crystal Structure Determination
2015
Related Article: Rodolphe Kinghat, Gérard Schmitt, Kabula Ciamala, Abderrahim Khatyr, Michael Knorr, Sandrine Jacquot-Rousseau, Yoann Rousselin, Marek M. Kubicki|2016|Comptes Rendus Chimie|19|320|doi:10.1016/j.crci.2015.09.017
Efficient Synthesis and X-ray Structure of [1,2,4]Triazolo[4,3-a]pyridines via Oxidative Cyclization Using N-Chlorosuccinimide (NCS)
2021
Triazolopyridines are a family of compounds that, owing to their biological activity, have many pharmaceutical applications. In this study, 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine and 6-bromo-3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine were synthesized by using the chlorinated agent NCS for hydrazones under very mild conditions. The characterization of these compounds was achieved by 1H NMR, 13C NMR, FTIR, MS and X-ray diffraction. The compound 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine was crystallized in the monoclinic space group P 21/c with a = 15.1413(12), b = 6.9179(4), c = 13.0938(8) Å, β = 105.102(6)°, V = 1324.16(16)Å3, Z = 4, and R = 0.0337. Also compound 6-bro…
Orthogonal functionalisation of upconverting NaYF4 nanocrystals.
2013
A simple and straightforward method for the orthogonal functionalisation of upconverting NaYF4 nanocrystals (UCNCs)-doped withYb(3+) and Er(3+)-based on N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide (EDC/NHS) selective reactions between two dyes and two different reactive groups present at the periphery of the upconverting nanocrystals is reported. Organic-soluble UCNCs of 10 and 50 nm in size are encapsulated efficiently in a 1:1 mixture of two commercial 3000 Da poly(ethylene glycol) derivatives with two different reactive groups (amino and carboxylic groups). The water-dispersible UCNCs are non-cytotoxic, stable in the physiological environment, and present free ami…
El sentido alusivo de singularis en el discurso ciceroniano pro Sulla
2012
Después de haber propuesto que el uso frecuente de singularis en las Verrinas está en buena parte motivado por la alusión aprina que suscitan los nombres parlantes de Verres y de su principal colaborador Apronius, se nos ha opuesto el reparo de que el uso relativo de ese adjetivo es superior en el Pro Sulla. Pues bien, hecho el oportuno análisis, comprobamos que dos de los seis empleos de singularis en este discurso apuntan el mismo valor alusivo. Y los motivos son paralelos: Sulla facilita la conexión con el término genérico del cerdo doméstico o salvaje (sus, suis) y la conducta predatoria del personaje justifi ca la alusión, como en el caso de las Verrinas
A DFT study of the domino reactions between imidazole NHC, ketenimines and DMAD or MP acetylene derivatives yielding spiro-pyrroles
2014
Abstract The domino reactions of imidazole carbene 9, ketenimine 10 and DMAD 5 or MP 7 to yield the formal [3+2] cycloadducts 12 or 14 have been investigated using DFT methods at the B3LYP/6-31G* level. These domino reactions are initialized by the nucleophilic attack of imidazole 9 on ketenimine 10 to yield the zwitterionic intermediate 11. The second reaction is a formal [3+2] cycloaddition (32CA) reaction between the zwitterionic intermediate 11 and acetylene carboxylates DMAD 5 or MP 7 yielding spiro-pyrroles 12 and 14. These formal 32CA reactions are initialized by the nucleophilic attack of the N3 nitrogen of intermediate 11 on the most electrophilic centres of these acetylene derivat…
Nonlinear concave-convex problems with indefinite weight
2021
We consider a parametric nonlinear Robin problem driven by the p-Laplacian and with a reaction having the competing effects of two terms. One is a parametric (Formula presented.) -sublinear term (concave nonlinearity) and the other is a (Formula presented.) -superlinear term (convex nonlinearity). We assume that the weight of the concave term is indefinite (that is, sign-changing). Using the Nehari method, we show that for all small values of the parameter (Formula presented.), the problem has at least two positive solutions and also we provide information about their regularity.
The energy minimization problem for two-level dissipative quantum systems
2010
In this article, we study the energy minimization problem of dissipative two-level quantum systems whose dynamics is governed by the Kossakowski–Lindblad equations. In the first part, we classify the extremal curve solutions of the Pontryagin maximum principle. The optimality properties are analyzed using the concept of conjugate points and the Hamilton–Jacobi–Bellman equation. This analysis completed by numerical simulations based on adapted algorithms allows a computation of the optimal control law whose robustness with respect to the initial conditions and dissipative parameters is also detailed. In the final section, an application in nuclear magnetic resonance is presented.
Las obras que nunca se acaban. El mantenimiento de los castillos en la Valencia Medieval: sus protagonistas y sus materiales
2003
A partir del estudio de los cuadernos de cuentas de distintas obras llevadas a cabo en los castillos valencianos a lo largo de los siglos XIV y XV, el objeto del presente artículo es analizar la organización de esas campañas de mantenimiento. De esta manera, se observa en primer lugar la mano de obra, desde los maestros al concurso de personal sin cualificar, en su mayoría jóvenes de la localidad y en algunos casos también mujeres; más tarde se estudian las áreas de abastecimiento de materiales y las estrategias para obtenerlos; y por último se hace un repaso a las obras emprendidas, que sin duda ayudará a comprender la forma y función de estas fortalezas, así como las debilidades de las té…
Dalla Word Sense Disambiguation alla sintassi: il problema dell'articolo partitivo in italiano
2017
Out of context, a sequence of Italian such as dei professori 'of.the teachers' is ambiguous: it can either mean some teachers (e.g. Dei professori intervennero 'Some teachers attended') or carry the value of a Saxon genitive (e.g. i libri dei professori 'the teachers' books'). The part of speech to which dei professori belongs cannot be identified: dei could be a partitive article in a noun phrase or a preposition in a prepositional phrase. This key difference raises a problem in the area of Word Sense Disambiguation. Despite its relevance for NLP, this case of homonymy has so far been disregarded in the literature. The paper distinguishes the functions of grammar morphemes such as dei and …
On the optimal design of multi-stage cascaded transistor amplifiers with noise, gain and mismatch constraints
2007
The problem of evaluating the optimal performances of cascaded, unbalanced, multi-stage transistor amplifiers is addressed. In particular, a theoretically rigorous approach is proposed for the determination of a family of Optimal Design Curves (ODC's) which express the best noise-gain tradeoff that can be achieved - at each frequency and device operating condition - when a simultaneous constraint on amplifier input VSWR is accounted for. Such curves can be used as a more meaningful starting point in practical amplifier design in place of the approximate calculations so far employed for target performance or optimization goals determination.