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j.urnal of Applied Mathematics and Physics 2015年第9期3卷 1168-1177页

作者： enrique j. chicurel-uziel Francisco A. Godínez Instituto de Ingeniería Universidad Nacional Autónoma de México México D.F. México

The representation of the Dirac delta, obtained by differentiating the parametric equation of the unit step with a riser, is used to solve two examples referring to problems of a different physical nature, each with the product of two deltas as a forcing function. Each problem was solved by an entirely different procedure. In comparison with non-parametric solutions, the present solutions are both more accurate and truer representations of the physics involved.

关键词： Dirac Delta Partial Differential Equations Parametric Representation

Parametric Dirac Delta to Simplify the Solution of Linear and Nonlinear Problems with an Impulsive Forcing Function

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j.urnal of Applied Mathematics and Physics 2013年第7期1卷 16-25页

作者： enrique j. chicurel-uziel Francisco A. Godínez-Roj.no Instituto de Ingeniería Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de México México D.F. México

The Laplace transform is a very useful tool for the solution of problems involving an impulsive excitation, usually represented by the Dirac delta, but it does not work in nonlinear problems. In contrast with this, the parametric representation of the Dirac delta presented here works both in linear and nonlinear problems. Furthermore, the parametric representation converts the differential equation of a problem with an impulsive excitation into two equations: the first equation referring to the impulse instant (absent in the conventional solution) and the second equation referring to post-impulse time. The impulse instant equation contains fewer terms than the original equation and the impulse is represented by a constant, j.st as in the Laplace transform, the post-impulse equation is homogeneous. Thus, the solution of the parametric equations is considerably simpler than the solution of the original equation. The parametric solution, involving the equations of both the dependent and independent variables in terms of the parameter, is readily reconverted into the usual equation in terms of the dependent and independent variables only. This parametric representation may be taught at an earlier stage because the principle on which it is based is easily visualized geometrically and because it is only necessary to have a knowledge of elementary calculus to understand it and use it.

关键词： Dirac Delta Parametric Representation Nonlinear Differential Equations Impulsive Problems

Flavor violating Higgs signals in the Texturized Two-Higgs Doublet Model (THDM-Tx)

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Chinese Physics C 2016年第12期40卷 22-36页

作者： M. A. Arroyo-Urefna j. Lorenzo Diaz-Cruz enrique Diaz j.vier A. Orduz-Ducuara Facultad de Ciencias Fisico-Matematicas Benemerita Universidad Autonoma de Puebla C.P. 72570 Puebla Pue. Mexico.

Flavor violating Higgs signals, such as the top FCNC decay t→ch0 and the LFV Higgs decay h0→τμ, have been studied at the LHC. These signals can arise within the general Two-Higgs Doublet Model （THDM）, where each Higgs doublet couples to all fermion types through Yukawa matrices Yf 1 and Y f2 . The Yukawa matrices can be assumed to have the same form or they could have different structures. In this paper we study the case when both Yf1 and Y f2 have completely different forms, but in such a way that they complement to produce a specific hermitian mass matrix. We find that for specific four-zero textures, the flavor violating Higgs couplings depend only on the free parameters tan β, γf and the fermion masses. We use the current bounds on the low energy processes to derive constraints on the heavy Higgs boson mass, tanβand γf Then, we use these constraints to evaluate the LFV Higgs decays, which reach branching ratios that could be tested at the LHC.

关键词： THDM LFV textures

Caving performance through the integration of microseismic activity and numerical modeling at DOZ-PT Freeport,Indonesia

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International j.urnal of Minerals,Metallurgy and Materials 2009年第1期16卷 1-6页

作者： Rubio enrique Napitupulu Daulat Mining Engineering Department Universidad de Chile Geotechnical Engineering Department PT Freeport IndonesiaTembagapuraIndonesia

This article describes an undergoing research at PT Freeport, Indonesia, in which the main goal is to use the microseismic information recorded as a result of mining to analyze cave propagation and stress performance on the actual production and fixed infrastructure. At the moment, several numerical experiments have been conducted to correlate the mining activity with the microseismic events using the data collected during year 2005 and 2006. As a result of the preliminary analysis a micro- and a macrocracking envelop were proposed on the basis of computation of stress behavior at the location of the events. Stresses have been computed using standard elastic continuous boundary element models. The correlation between the average source radius and the stress performance has provided a method to propose a macrocracking criterion. Several techniques have been tested to nucleate the microseismic activity around different geological features. This last attempt was aimed to look at potential overstresses induced over the undercut and extraction level drifts. A method was devised to integrate the microseismicity into a 3-dimensional ride distribution model. This model has shown to be very effective to quantify the overstress induced as a result of computing volumetric microseismicity density. The volumetric microseismic model showed to induce overstress up to 10 MPa over a period of two months. The future work will concentrate on the calibration of the integrated model with actual damage observations made at the current mining infrastructure.

关键词： microseism underground mining block caving stress distribution microcrack criterion

The Category of Humanity: Language as a Reflection of the Opposition between the Natural Sphere and the Human Sphere

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Language and Semiotic Studies 2019年第2期5卷 37-52页

作者： enrique j.Vercher García University of Granada

The article analyses the way in which human languages classify reality into two large categories: the natural sphere and the human sphere. Thus, a given language will use the resources of its different linguistic levels(phonetic-phonological, morphological, syntactic, and lexical) to configure the references of reality and classify them based on what the speaker considers as belonging to the sphere of human society or the sphere of nature, outwith the human community. The same obj.ct, animal, phenomenon, or event may be treated(and evaluated) differently depending on whether the speakers of a given language consider it as belonging to the human sphere or the natural sphere.

关键词： linguistics cognitive linguistics linguistic anthropology linguoculturology natural languages linguistic categories human/non-human

Effect of an electron gas on a neutron-rich nuclear pasta

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Nuclear Science and Techniques 2015年第2期26卷 75-82页

作者： j.rge Alberto Lopez enrique Ramirez-Homs Department of Physics University of Texas at El Paso

We studied the role that electron gas has on the formation of nuclear structures at subsaturation densities and low temperatures(T<1 Me V).Using a classical molecular dynamics model we studied isospin symmetric and as... 详细信息

We studied the role that electron gas has on the formation of nuclear structures at subsaturation densities and low temperatures(Tj.cts,reduces the isospin content,and modifies the nucleon average displacement,but does not affect the inter-nucleon distance in *** nuclear structures are also found to change shapes by different degrees depending on their isospin content,temperature and density.

关键词：电子气体分子动力学模型面食中子相互作用强度核结构同位旋平均位移

Single droplet drying of detergents:Experimentation and modelling

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Particuology 2021年第5期19卷 35-47页

作者： Borj. Hernandez Rosa Mondragon Mark A.Pintoa Leonor Hernandez j.enrique j.lia j.an Carlos j.rque Sergio Chiva Mariano Martin Newcastle Innovation Centre Procter&Gamble R&DNewcastle upon TyneUK Departamento de Ingenieria Quimica y Textil.Universidad de Salamanca SalamancaSpain Departamento de Ingenieria Mecanica y Construccion Universitat Jaume ICastellon de la PlanaSpain Instituto de Tecnologia Ceramica Universitat Jaume ICastellon de la PlanaSpain

This study evaluates the single droplet drying(SDD)of *** data are used to validate a theoretical multistage *** experiments are carried out in an acoustic levitator analysing six different detergent formulations at 393 *** work is completed by developing a model based on conservation *** model is composed of the three stages observed in the drying *** the first stage,an external surface drying stage occurs until the surface is saturated and the crust is *** the next stage,the drying rate is governed by diffusion through the *** the same time,the particle heats up until boiling conditions are achieved in the core of the *** this point,the third stage *** the final stage,the droplet core is in boiling conditions which are governed by the pressure drop through the crust and the concentration of *** model has been evaluated for the different formulations being flexible to predict the drying of different mixtures with good accuracy.

关键词： Drying Single droplet Acoustic levitator Detergents

Local hardening and asymmetric twin growth by twin-twin interactions in a Mg alloy

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j.urnal of Magnesium and Alloys 2023年第1期11卷 176-191页

作者： Krishna Yaddanapudi Mariyappan Arul Kumar j.axiang Wang Xin Wang Timothy j.Rupert enrique j.Lavernia j.lie M.Schoenung Irene j.Beyerlein Subhash Mahaj.n Department of Materials Science and Engineering University of CaliforniaDavisCA 95616USA Materials Science and Technology Division Los Alamos National LaboratoryLos AlamosNM 87545USA Department of Mechanical Engineering Materials DepartmentUniversity of CaliforniaSanta BarbaraCA 93106USA Department of Materials Science and Engineering University of CaliforniaIrvineUSA Materials Department University of CaliforniaSanta BarbaraCA 93106USA

In this study,the role of twin-twin interactions on the distributions of local defects(e.g.,dislocations)and stress fields in a magnesium alloy is investigated.A co-zone(1012)-(1012)tensile twin j.nction in a deformed Mg-3wt.%Y alloy is analyzed using transmission electron microscopy(TEM).The results show that the morphology of the impinging(1012)twin is asymmetric,and the non-interacting boundary of the recipient(1012)twin is *** analysis of TEM images reveals that type-II pyramidal[1213](1212)dislocations concentrate in the vicinity of the twin-twin j.nction *** samedislocations are also observed inside the interacting twin domains along with a few ***dislocations emanating from the impinging(1012)twin boundary have edge character and are extended with faults parallel to the basal *** contrast,thedislocations connected to the recipient(1012)twin are predominantly screw orientation and ***-viscoplastic fast Fourier transform based crystal plasticity calculations are performed to rationalize the observed twin morphology and local dislocation *** model calculations suggest that the local stress fields generated at the j.nction site where the two twins meet are responsible for the experimentally observed concentration of*** calculated stress fields are asymmetric with respect to the j.nction site,explaining the observed asymmetric morphology of the impinging ***,these findings show strong effects of twin-twin interactions on the distribution of dislocations as well as the evolution of the twinned microstructure and as such,can help advance understanding of twinning in Mg alloys and their effect on mechanical behavior.

关键词： Tensile twins Twin-twin intersections Mg alloys Crystal plasticity TEM

Surfactant Assisted Dispersion and Adhesion Behavior of Carbon Nanotubes on Cu—Zr and Cu—Zr—Al Amorphous Powders

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j.urnal of Materials Science & Technology 2014年第9期30卷 847-853页

作者： j.nathan Nguyen Haiming Wen Zhihui Zhang Frank Yaghmaie enrique Lavernia Department of Chemical Engineering and Materials Science University of California at DavisDavis CA 95616 USA Northern California Nanotechnology Center University of California at DavisDavis CA 95616 USA

Carbon nanotubes （CNTs） were dispersed in gas atomized Cu47.5Zr47.5Al5 （CZA） and CusoZrso （CZ） amorphous powders, in an effort to elucidate the mechanisms of adhesion of CNTs onto amorphous metallic powders. CNTs were homogenously dispersed in water using a zwitterionic （ZW） surfactant. Then CZA and CZ powders were submersed in the ZW-CNTsuspensions with varying amounts of dwell time in an ultrasonic bath. The ZW-CNT- metal powder suspensions were dried, and CNT-metal composite powders were obtained after decomposition of the surfactant by calcination. Zeta potential measurements on ZW-CNT-metal powder suspensions and scanning electron microscopy investigation into the CNT-metal composite powders both indicated an ideal dwell time, for a specific alloy composition, of metallic powders in ZW-CNT suspension to achieve optimal adhesion of CNTs onto amorphous metallic powder surfaces. The results are rationalized on the basis of hydrolysis of metal ions into suspension creating a net positive charge on the metallic powder surfaces, and the interaction between the charged powder surfaces and the charged hydrophilic head groups of ZW, which has the other end attached to CNTs.

关键词： Metallic powders Carbon nanotubes Dispersion Surfactant Hydrolysis

Rapid on-site evaluation of endoscopic-ultrasound-guided fine-needle aspiration diagnosis of pancreatic masses

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World j.urnal of Gastroenterology 2014年第28期20卷 9451-9457页

作者： j.lio Iglesias-Garcia j.se Lario-Noia Ihab Abdulkader j.enrique Domínguez-Muoz Department of Gastroenterology and Hepatology Foundation for Research in Digestive DiseasesUniversity Hospital of Santiago de Compostela Department of Pathology University Hospital of Santiago de Compostela

Endoscopic ultrasound (EUS) has become an essential tool for the study of pancreatic diseases. Specifically, EUS plays a pivotal role evaluating patients with a known or suspected pancreatic mass. In this setting, differential diagnosis remains a clinical challenge. EUS-guided fine-needle aspiration (FNA) and fine-needle biopsy (FNB) have been proven to be safe and useful tools in this setting. EUS-guided FNA and FNB, by obtaining cytological and/or histological samples, are able to diagnose pancreatic lesions with high sensitivity and specificity. In this context, several methodological features, trying to increase the diagnostic yield of EUS-guided FNA and FNB, have been evaluated. In this review, we focus on the role of rapid on-site evaluation (ROSE). From data reported in the literature, ROSE may increase diagnostic yield of EUS-FNA specimens by 10%-30%, and thus, diagnostic accuracy. However, we should point out that many recent studies have reported adequacy rates of > 90% without ROSE, indicating that, perhaps, at high-volume centers, ROSE may not be indispensable to achieve excellent results. The use of ROSE can be considered important during the learning curve of EUS-FNA, and also in hospital with diagnostic accuracy rates < 90%.

关键词： Endoscopic-ultrasound-guided fine-needle aspiration Rapid on-site evaluation Solid pancreatic tumors Diagnostic accuracy