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201.
Pedro Velez-Herrera 《Journal of fluorine chemistry》2009,130(6):573-5575
A novel method for the synthesis of highly fluorinated benzoxazines in a high yield derived form a α,ω-diamine-polyfluoroalkane and α,ω-dianiline-polyfluoroalkane is described. The synthetic method increases the yield by 20% and reduces the reaction time by 90% in comparison to the currently known method, allowing synthesis of large quantity of highly fluorinated diamines. The diamines are used as the precursors for benzoxazine compounds. The diamines and benzoxazines are obtained in high yield and purity. The structures are characterized by nuclear resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FT-IR). 相似文献
202.
Pedro Ricardo López-Bautista Gabriel Daniel Villa-Salvador 《Israel Journal of Mathematics》2000,116(1):345-365
LetL/K be a finite Galoisp-extension of algebraic function fields of one variable over an algebraically closed fieldk of characteristicp, with Galois groupG=Gal(L/K). The space Ώ
L
s
(0) of semisimple holomorphic differentials ofL is thek-vector space of holomorphic differentials which are fixed by the Cartier operator. We obtain the isomorphism classes and
multiplicities of the summands in a Krull-Schmidt decomposition of thek[G]-module Ώ
L
s
(0) into a direct sum of indecomposablek[G]-modules.
Partially supported by CONACyT, project No. 25063-E. 相似文献
203.
Fernando Dures Patrícia M. A. Silva Pedro Novais Isabel Amorim Luís Gales Ctia I. C. Esteves Samuel Guieu Hassan Bousbaa Madalena Pinto Emília Sousa 《Molecules (Basel, Switzerland)》2021,26(11)
Thioxanthones are bioisosteres of the naturally occurring xanthones. They have been described for multiple activities, including antitumor. As such, the synthesis of a library of thioxanthones was pursued, but unexpectedly, four tetracyclic thioxanthenes with a quinazoline–chromene scaffold were obtained. These compounds were studied for their human tumor cell growth inhibition activity, in the cell lines A375-C5, MCF-7 and NCI-H460. Photophysical studies were also performed. Two of the compounds displayed GI50 values below 10 µM for the three tested cell lines, and structure–activity relationship studies were established. Three compounds presented similar wavelengths of absorption and emission, characteristic of dyes with a push-pull character. The structures of two compounds were elucidated by X-ray crystallography. Two tetracyclic thioxanthenes emerged as hit compounds. One of the two compounds accumulated intracellularly as a bright fluorescent dye in the green channel, as analyzed by both fluorescence microscopy and flow cytometry, making it a promising theranostic cancer drug candidate. 相似文献
204.
David Ruiz Carlos Torralba Jesús Puchades Marco Iván Olivé Calzada Verónica Pomar Susana Polo Pedro Llovera Vicente Fuster Francisco Magraner 《Journal of Electrostatics》2009,67(2-3):496-500
Nowadays the electrical activity measured in tall objects has been widely characterized, but the collected data of lightning rods installed in buildings do not amount to enough to obtain reliable statistics. The measures stored at relatively few points are not representative of the different types of installations. Furthermore, the protection model applied for lightning air terminal installations is based on theoretical models. This paper describes the design of a micro-station to measure some lightning parameters in real lightning air terminal installations correlated to the nature of emplacement instead of triggering lightning or choosing points with a high number of lightning impacts. 相似文献
205.
We provide necessary and sufficient conditions for the existence of T-periodic solutions of a system of second-order ordinary differential equations that models the motion of two or three collinear charged particles of the same sign. 相似文献
206.
Victoria Hernández-Mederos Pedro L. del Ángel Jorge Estrada-Sarlabous 《Numerical Algorithms》2008,48(1-3):29-47
In this paper we propose an advancing front method for generating an isotropic triangular mesh on a regular parametric surface. Starting from a point on the surface, the method computes a set of points in the intersection curve between the surface and the sphere centered at that point with a prescribed radius. From this set we select the vertices of a cell composed by triangles approximately equilateral. The mesh grows repeating the described computation with boundary vertices of the cell as starting points. Compared to methods proposed by other authors, the current method may be considered as an improvement, since it is more efficient and flexible. Furthermore, the resulting mesh is closer to being isotropic. Additionally, we obtain a sufficient condition ensuring that a surface triangulation is of Delaunay type. 相似文献
207.
Arantza Estévez-Fernández Peter Borm Pedro Calleja Herbert Hamers 《Annals of Operations Research》2008,158(1):189-203
Two classes of one machine sequencing situations are considered in which each job corresponds to exactly one player but a
player may have more than one job to be processed, so called RP(repeated player) sequencing situations. In max-RP sequencing
situations it is assumed that each player’s cost function is linear with respect to the maximum completion time of his jobs,
whereas in min-RP sequencing situations the cost functions are linear with respect to the minimum completion times. For both
classes, following explicit procedures to go from the initial processing order to an optimal order for the coalition of all
players, equal gain splitting rules are defined. It is shown that these rules lead to core elements of the associated RP sequencing
games. Moreover, it is seen that min-RP sequencing games are convex.
We thank two referees for their valuable suggestions for improvement.
Financial support for P. Calleja has been given by the Ministerio de Educación y Ciencia and FEDER under grant SEJ2005-02443/ECON,
and by the Generalitat de Catalunya through a BE grant from AGAUR and grant 2005SGR00984. 相似文献
208.
Heizir F. De Castro Regina Y. Moriya Pedro C. Oliveira Cleide M. F. Soares 《Applied biochemistry and biotechnology》1999,79(1-3):817-826
The feasibility of using mixtures of C4 and C5 chain-length aliphatic alcohols from fusel oil as the bulk organic media for lipase-mediated synthesis of laurate esters was assessed. Reaction mixtures consisted of lauric acid, lipase, solvent (if added), and appropriate amount of fusel oil (previously dehydrated with inorganic salts and molecular sieves). The influence of the reaction conditions such as substrate concentrations and temperature were investigated. Increased molar ratio of acyl donor to acyl acceptor allowed the esterification to proceed with no need for solvent addition. 相似文献
209.
210.
The main purpose of this paper is to perform a sensitivity analysis where we quantify and analyse the effects on the mean of the profit on an Income Protection policy and two risk measures of changing the values of the transition intensities. All the calculations carried out are based on a multiple state model for Income Protection proposed in Continuous Mortality Investigation Committee (Continuous Mortality Investigation Reports 1991; 12 ). Within this model, we derive a formula for the mean of the profit, which enables to evaluate it more efficiently. In order to calculate the two risk measures we use the numerical algorithms for the calculation of the moments of the profit proposed by Waters (Insurance: Mathematics and Economics 1990; 9 :101–113). We carry out the sensitivity analysis considering two different situations: in the first situation, we update the premium rates used to calculate the moments of the profit, according to the changes in the values of the transition intensities; in the second one, we do not update the premium rates. Both analyses are of practical interest to insurance companies selling Income Protection policies. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献