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Luminescence Characteristics of LaAlO<sub>3</sub>:Eu<sup>3+</sup>Obtained by Modified Pechini’s Method

Open Journal of Synthesis Theory and Applications 2017年第1期6卷 1-12页

作者： Alfredo Morales Hernández Mayra A. de León Alfaro Antonio Barrera Villatoro Ciro Falcony Teodoro Rivera Montalvo juan zarate medina Instituto de Investigaciones en Metalurgia y Materiales Universidad Michoacana de San Nicolás de Hidalgo Morelia México Instituto Politécnico Nacional Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada Ciudad de México México Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Ciudad de México México

The aim of the present work was to investigate the luminescent properties of europium-doped lanthanum aluminate (LaAlO3) powder prepared by Modified Pechini (MP) method. Samples were prepared at different Eu3+ concentrations and calcined at 1600°C. Structural and morphology characterizations were obtained by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). Luminescent properties were analyzed by photoluminescence (PL) and thermoluminescent phenomena. The XRD pattern shows pure lanthanum aluminate oxide LaAlO3 with a rhombohedral structure. Photoluminescence studies of the powders was related to 4f → 4f(5D0 → 7Fi) (i = 1, 2, 3, 4) transitions of Eu3+ ion, the most intense emission of Eu3+ in LaAlO3 was registered for the transition 5D0 → 7F1, for 5% of Eu3+. The recorded TL glow curves of excited samples showed a main TL peak, the main peak appeared its maximum as a function of excitation energy. The investigation demonstrates that polycrystalline LaAlO3:Eu3+ powders calcined at 1600°C have interesting luminescent characteristics.

关键词： Modified Pechini Method LaAlO3:Eu3+ Photoluminescence Thermoluminescence

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A coupled fluid FEM-DEM technique for predicting blasting operations in tunnels

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Underground Space 2018年第4期3卷 310-316页

作者： Francisco zarate Jose M.Gonzalez juan Miquel Rainald Lohner Eugenio Onate Centre Internacional de Metodes Numerics en Enginyeria(CIMNE) Spain Universitat Politecnica de Catalunya(UPC) Gran Capitan s/nCampus Nord08034 BarcelonaSpain George Mason University USA1

We present recent developments in the coupling of the finite element method(FEM)and the discrete element method(DEM)for the analysis of rock blasting operations in *** coupled FEM-DEM technique has been proven to be an efficient procedure for pre-dicting the multiple fractures of rock induced by the loads generated in *** coupled FEM-DEM procedure is applied in tunnel construction,as well as to gas pressure blasting pyrotechnics to break rocks for the excavation of the tunnel *** the latter case,the effect of gas explosion is modeled by solving the equations of gas dynamics in the analysis domain using *** effect of gas forces in the underlying rock mass is modeled via an embedded fluid-structure interaction *** efficiency of the coupled FEM-DEM tech-nique is demonstrated in several examples of fracture tests and rock blasting problems related to tunnel *** examples pre-sented indicate that the combination of the DEM with simple three-node linear triangular elements(for two-dimensional problems)captures the onset of fractures and their evolution accurately,accounting for the penetration of gas in the failure domain(zarate&Onate,2015;zarate,Cornejo,&Onate,2018).

关键词： Discrete elements Finite elements Fracture mechanics FEM-DEM Gas dynamics

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Commercially Important Marine Mollusks for Human Consumption in Acapulco,Mexico

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Natural Resources 2012年第1期3卷 11-17页

作者： Rafael Flores-Garza Sergio Garcia-Ibanez Pedro Flores-Rodriguez Carmina Torreblanca-Ramirez Lizeth Galeana-Rebolledo Arcadio Valdes-Gonzalez Arquimedes Suastegui-zarate juan Violante-Gonzalez Unidad Academica de Ecologia Marina Universidad Autonoma de GuerreroAcapulcoMexico Facultad de Ciencias Biologicas Universidad Autonoma de Nuevo LeonCiudad UniversitariaSan Nicolas de los GarzaMexico

Acapulco, offers for international tourism a variety of mollusks that are delightful to the palate and a source of economic revenue for its residents;however there are no studies on the species consumed. Furthermore, data from the State agencies responsible for registration of these products are unclear. This work is aimed to develop an inventory of Gastropoda, Bivalvia and Polyplacophora marketed as food, to gain knowledge on the species native to Acapulco and the introduced ones. The places that sell shellfish were interviewed from 2008 to 2011 in order to determine the geographical origin of their products being offered. We identified 42 species: 15 species of gastropods are captured locally and three are introduced. On Bivalvia, seven species are caught locally and 16 are introduced. There are Bivalvia species caught locally;however, their capture is now unaffordable. It is likely that this situation is due to overfishing and/or the transmission of diseases or parasites caused by the introduction of foreign living organisms to Acapulco. Within the list of species caught locally, there are some listed as of subject protection;all of these organisms are exploited in Acapulco without control. The wealth of marine mollusks for human consumption in Acapulco is very high. The capture does not satisfy local market demand and the amount of introduced species is very high. It is necessary to make a diagnostic analysis of mollusk fishing industry in the state of Guerrero, also implement a management program, including the sanitary measures and control of introduced species, as they arrive alive and stay alive in the waters of Acapulco. A significant number of native species that have aquaculture potential should be studied for commercial culture practice as well as to conduct studies on their biology on those species that are considered over-exploited and allow recovery of the species in its habitat.

关键词： Mollusks Commercial Consumption Human Acapulco México

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Congenitally Corrected Transposition of the Great Arteries: Conduction Anomalies: A Case Report

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World Journal of Cardiovascular Diseases 2021年第9期11卷 439-444页

作者： Jose Antonio Luna-Alvarez-Amezquita Javier Ivan Armenta-Moreno Joaquin Berarducci Jorge Luis Bermudez-Gonzalez Jose Luis Siller-Nava Edson Alberto Escandón-Villalobos Nilda Espinola-Zavaleta Roberto Cano-zarate juan Ignacio Straface Department of Nuclear Cardiology National Institute of Cardiology Ignacio Chavez Mexico City Mexico Department of Echocardiography ABC Medical Center I.A.P. Mexico City Mexico Department of Magnetic Resonance National Institute of Cardiology Ignacio Chavez Mexico City Mexico

Introduction: Congenitally corrected transposition of the great arteries (CCTGA) is a rare heart disease that encompasses an atrioventricular and ventriculoarterial discordance and accounts for less than 1 percent of congenital heart diseases. Objective: To present an atypical case of a man with complex congenital heart disease and conduction anomalies. Case Presentation: This is a case of a 34-year-old patient who came to the hospital with 1 week of dyspnea on exertion and episodes of lipothymia. The patient was referred to our hospital after an electrocardiogram from his primary care with evidence of blocked atrial fibrillation. During the initial evaluation blocked atrial fibrillation was confirmed with a rescue ventricular rate of 38 bpm. A magnetic resonance confirmed the presence of the atrioventricular and ventriculoarterial discordance, the aorta had a left anterior position, perimembranous ventricular septal defect with a right to left shunt, biventricular systolic dysfunction, moderate tricuspid, and mitral regurgitation, interventricular septal intramyocardial and biatrial fibrosis, left atrial dilation, and dilation of the pulmonary artery. After pacemaker placement, the patient has an improvement in his clinical symptoms and quality of life. Conclusions: Cardiac arrhythmias are CCTGA’s leading cause of death, mostly ventricular tachycardia, and atrial fibrillation. Right bundle branch block is a previously unreported and potentially very rare presentati

关键词： Congenital Heart Disease Congenitally Corrected Transposition of the Great Arteries Cardiac Magnetic Resonance Echocardiography Arrhythmia

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