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Journal of Pharmaceutical Analysis 2019年第1期9卷 62-69页

作者： Verónica Arancibia Johisner Penagos-Llanos Edgar Nagles Olimpo García-Beltrán John J.Hurtado Pontificia Universidad Católica de Chile Facultad de Química facultad de ciencias naturales y matemáticas Universidad de Ibagué departamento de Química Universidad de los Andes

This study presents for the first time a new composite of carbon paste(CP), single-walled carbon nanotubes(SWCNTs) and Nd2 O3(NdOX). This versatile composite(NdOX-SWCNT/CPE) was applied to the oxidation of paracetamol(PCM). The newly formed surface was characterized by scanning electron microscopy(SEM), electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV). The results showed greater conductivity and a higher surface area for the composite than those of the carbon paste alone. Moreover, the anodic peak currents for PCM increased from 1.6 to 3.6 m A with CPE and NdOXSWCNT/CPE, indicating an increase of nearly 51.0% for the anodic peak current. On the other hand, the anodic peak potentials shifted from 0.67 to 0.57 V. The detection limits were 0.05 mmol/L with NdOXSWCNT/CPE and 0.50 mmol/L with SWCNT/CPE. The relative standard deviations(RSDs) were 1.5%(n=7). The accuracy and interference of the methods were evaluated with a urine chemistry control spiked with known quantities of PCM, uric acid, dopamine, ascorbic acid, caffeine, acetylsalicylic acid,tartrazine, sunset yellow, allure red, rutin, morin and metal ions. Finally, the novelty and usefulness of the composite were evaluated to quantify PCM in pharmaceutical dosage forms such as tablets, powders and syrups for children.

关键词： Paracetamol Neodymium(Ⅲ) Oxide Single-walled carbon nanotubes Pharmaceutical dosage

Mechanical response to axial strain in WS2 nanotubes

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Progress in Natural Science:Materials International 2021年第6期31卷 898-903页

作者： S.Mejía-Rosales S.A.Sandoval-Salazar A.Soria-Sánchez J.D.Vázquez-Palafox Centro de Investigación en ciencias Físico-matemáticas (CICFIM) Facultad de Ciencias Físico-Matemáticas Universidad Autónoma de Nuevo León facultad de ciencias Físico-matem aticas Universidad Aut onoma de Nuevo León facultad de ciencias Físico-matemáticas Universidad Autónoma de Nuevo León

In order to take advantage of inorganic nanotubes for their use with pragmatic purposes, characterization of their mechanical properties becomes a relevant issue. In the present study, a series of results on the mechanical properties of WS2nanotubes of several diameters and two main lattice orientations was obtained by the implementation of molecular dynamics simulations using an interatomic potential of the Stillinger-Weber kind. A young’s modulus for nanotubes of H polytype close to 170 GPa was obtained in accordance with experimental results, and of ≈ 130 GPa for nanotubes of the T polytype, with almost no dependance on the diameter of the nanotube. The tensile strength was as large as 20 GPa(H armchair nanotubes, close to the value obtained in experiments), and the strain at the point of rupture reached values close to 0.24. The effect of several kinds of defects on the mechanical properties was investigated, and the results showed that when the defects consisted in the absence of a whole WS2unit, the tensile strength and point of rupture dropped considerably, and the fracture became more brittle than in pristine nanotubes. The dependence of the mechanical properties on temperature was also investigated.

关键词： Tungsten disulfide nanotubes young's modulus Stillinger-weber Molecular dynamics

Ligand effects on the structure and vibrational properties of the thiolated Au18 cluster

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Progress in Natural Science:Materials International 2016年第5期26卷 510-515页

作者： Alfredo Tlahuice-Flores CICFIM-facultad de ciencias Físico-matemáticas Universidad Autónoma de Nuevo León

Most of the studies devoted to thiolated gold clusters suppose that their core and Au-S framework do not suffer from distortion independently of the protecting ligands（-SR） and it is assumed as correct to simplify the ligand as SCH3. In this work is delivered a systematic study of the structure and vibrational properties（IR and Raman）of the Au18（SR）14cluster. The pursued goal is to understand the dependency of the displayed vibrational properties of the thiolated Au18cluster with the ligands type. A set of six ligands was considered during calculations of the vibrational properties based on density functional theory（DFT） and in its dispersioncorrected approach（DFT-D）.

关键词： Gold cluster Ligand effects Structure Vibration Au18(SR)14 density functional theory

A generalization of the half-normal distribution

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Applied Mathematics(A Journal of Chinese Universities) 2016年第4期31卷 409-424页

作者： yolanda M. Gomez Ignacio Vidal departamento de matemáticas facultad de ciencias universidad de católica del norte Antofagasta Chile instituto de matemática y física universidad de talca Chile

In this paper we introduce an extension of the half-normal distribution in order to model a great variety of non-negative data. Its hazard rate function can be decreasing or increasing, depending on its parameters. Some properties of this new distribution are presented. For example, we give a general expression for the moments and a stochastic representation. Also, the cumulative distribution function, the hazard rate function, the survival function and the quantile function can be easily evaluated. Maximum likelihood estimators can be computed by using numerical procedures. Finally, a real-life dataset has been presented to illustrate its applicability.

关键词： half-normal distribution generalized half-normal distribution maximum likelihood estimate

Contrasting levels of genotype by environment interaction for life history and morphological traits in invasive populations of Zaprionus indianus(Diptera:Drosophilidae)

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Insect Science 2020年第5期27卷 1090-1100页

作者： Nicolas J.Lavagnino Marcos Imberti Victoria E.Ortizj Nicolas Flaibani Juan Jose Fanara Laboratorio de Evolucion Departamento de EcologiaGenetica y EvolucidnFacultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresArgentina IEGEBA-CONICET Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresArgentina

It has been demonstrated that phenotypic plasticity and genotype by envi-ronment interaction are important for coping with new and heterogeneous environments during *** indianus Gupta(Diptera:Drosophilidae)is an Afrotropical invasive fly species introduced to the South American continent in *** species is generalist and polyphagous,since it develops and feeds in several different fruit *** characteristics of *** suggest that phenotypic plasticity and genotype by environment interaction may be important in this species invasion *** this sense,our aim was to investigate the role of genetic variation for phenotypic plasticity(geno-type by environment interaction)in *** invasion of the South American ***,we quantified quantitative genetic variation and genotype by environment in-teractions of morphological and life history traits in different developmental environments,that is,host *** was done in different populations in the invasive range of ***-anus in *** showed that *** populations have considerable amounts of quantitative genetic ***,genotype by environment interactions was detected for the different traits analyzed in response to the different developmental ***,the amounts and patterns of these parameters differed between *** interpreled these results as the existence of diferences in evolutionary potential be-tween populations that have an important role in the short-and long-term success of the *** invasion process.

关键词： biological invasion genotype by env ironment interaction invaded range life history traits morphological traits Zaprionus indianus

Automorphism Groups of Pseudo-real Riemann Surfaces of Low Genus

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Acta Mathematica Sinica,English Series 2014年第1期30卷 11-22页

作者： Emilio BUJALANCE Antonio F.COSTA departamento de matemáticas Fundamentales Facultad de CienciasUNEDSenda del rey928040 MadridSpain

A pseudo-real Riemann surface admits anticonformal automorphisms but no anticonformal *** obtain the classifcation of actions and groups of automorphisms of pseudo-real Riemann surfaces of genera 2,3 and *** instance the automorphism group of a pseudo-real Riemann surface of genus 4 is eitherC4orC8or the Fro¨benius group of order 20,and in the case ofC4there are exactly two possible topological *** MK P R,g be the set of surfaces in the moduli space MK g corresponding to pseudo-real Riemann *** obtain the equisymmetric stratifcation of MK P R,g for generag=2,3,4,and as a consequence we have that MK P R,gis connected forg=2,3 but MK P R,4has three connected components.

关键词： Riemann surface automorphism anticonformal automorphism moduli space

Fountain-Gould Left Orders for Associative Pairs

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Acta Mathematica Sinica,English Series 2006年第3期22卷 641-652页

作者： José A.ANQUELA Teresa CORTS Miguel GóMEZ LOZANO Mercedes SILES MOLINA departamento de matemáticas Universidad de Oviedo departamentode lgebra Geometríay TopologíaFacultad de CienciasUniversidad de MálagaCampus de Teatinos29071 MálagaSpain

In this paper, we introduce a notion of weak Fountain-Gould left order for associative pairs and give a Goldie-like theory of associative pairs which are weak Fountain Gould left orders in semiprime pairs coinciding w... 详细信息

关键词： Fountain-Gould left order Associtive pair Goldie theory

Variation of Parameters Formula and Gronwall Inequality for Differential Equations with a General Piecewise Constant Argument

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Acta Mathematicae Applicatae Sinica 2011年第4期27卷 561-568页

作者： Kuo-Shou CHIU Manuel PINTO departamento de matemótica Facultad de Ciencias BósicasUniversidad Metropolitana de Ciencias de la EducacinJ.P.Alessandri 774SantiagoChile departamento de matemóticas Facultad de CienciasUniversidad de ChileCasilla 653SantiagoChile

A variation of parameters formula and Gronwall type integral inequality are proved for a differential equation involving general piecewise alternately advanced and retarded argument.

关键词： variation of parameters formula Gronwall integral inequality alternately advanced and retarded argument

A Note on Extreme Points in Dual Spaces

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Acta Mathematica Sinica,English Series 2013年第3期29卷 471-476页

作者： Juan Francisco MENA-JURADO Juan Carlos NAVARRO-PASCUAL departamento de Análisis matemático Facultad de Ciencias Universidad de Granada departamento de lgebra y Análisis matemático Universidad de Almería

Given a normed space X it can be easily proven that every extreme point in Bx＊, the unit ball of X＊, is the restriction of an extreme point in Bx Our purpose is to study when the restrictions of extreme points in B... 详细信息

关键词： Extreme point Ll-predual M-ideal

Inequalities for the Extended Best Polynomial Approximation Operator in Orlicz Spaces

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Acta Mathematica Sinica,English Series 2019年第2期35卷 185-203页

作者： Sonia ACINAS Sergio FAVIER Felipe ZO departamento de matemática Facultad de Ciencias y Exactas NaturalesUniversidad Nacional de La Pampa Instituto de matemática Aplicada San Luis IMASLUniversidad Nacional de San Luis and CONICET departamento de matemática Universidad Nacional de San Luis

In this paper we pursue the study of the best approximation operator extended from L~Φ to L~φ, where φ denotes the derivative of the function Φ. We get pointwise convergence for the coefficients of the extended best approximation polynomials for a wide class of function f, closely related to the Calder′on–Zygmund class t_m^p(x) which had been introduced in 1961. We also obtain weak and strong type inequalities for a maximal operator related to the extended best polynomial approximation and a norm convergence result for the coefficients is derived. In most of these results, we have to consider Matuszewska–Orlicz indices for the function φ.

关键词： Orlicz spaces extended best polynomial approximation pointwise and norm convergence weak and strong type inequalities Orlicz indices