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Radicals and Kothe’s Conjecture for Skew PBW Extensions

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Communications in Mathematics and Statistics 2021年第2期9卷 119-138页

作者： armando Reyes Hector Suarez Departamento de Matematicas Universidad Nacional de ColombiaSede BogotaColombia Escuela de Matemáticas y Estadística Universidad Pedagogica y Tecnológica de ColombiaSede TunjaColombia

The aim of this paper is to investigate different radicals(Wedderburn radical,lower nil radical,Levitzky radical,upper nil radical,the set of all nilpotent elements,the sum of all nil left ideals)of the noncommutative rings known as skew Poincare–Birkhoff–Witt *** characterize minimal prime ideals of these rings and prove that the Kothe’s conjecture holds for these ***,we establish the transfer of several ring-theoretical properties(reduced,symmetric,reversible,2-primal)from the coefficients ring of a skew PBW extension to the extension itself.

关键词： Armendariz rings Kothe’s conjecture Skew PBW extensions

Second Order Multigrid Methods for Elliptic Problems with Discontinuous Coefficients on an Arbitrary Interface, I: One Dimensional Problems

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Numerical Mathematics(Theory,Methods and Applications) 2012年第1期5卷 19-42页

作者： armando Coco Giovanni Russo Dipartimento di Matematica e Informatica Universitàdi CataniaViale Andrea Doria695125CataniaItaly

In this paper we present a one dimensional second order accurate method to solve Elliptic equations with discontinuous coefficients on an arbitrary *** order accuracy for the first derivative is obtained as *** method is based on the Ghost Fluid Method,making use of ghost points on which the value is defined by suitable interface *** multi-domain formulation is adopted,where the problem is split in two sub-problems and interface conditions will be enforced to close the *** conditions are relaxed together with the internal equations(following the approach proposed in[10]in the case of smooth coefficients),leading to an iterative method on all the set of grid values(inside points and ghost points).A multigrid approach with a suitable definition of the restriction operator is *** restriction of the defect is performed separately for both sub-problems,providing a convergence factor close to the one measured in the case of smooth coefficient and independent on the magnitude of the jump in the *** tests will confirm the second order *** the method is proposed in one dimension,the extension in higher dimension is currently underway[12]and it will be carried out by combining the discretization of[10]with the multigrid approach of[11]for Elliptic problems with non-eliminated boundary conditions in arbitrary domain.

关键词： Elliptic equation discontinuous coefficient second order accuracy multigrid arbitrary interface jump conditions

A Study in the Variation of G

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Journal of High Energy Physics, Gravitation and Cosmology 2022年第3期8卷 558-578页

作者： armando Vega-Colon Jeffery A. Secrest Department of Physics and Astronomy Armstrong Campus Georgia Southern University Savannah USA

There are indications that the Newtonian gravitational constant may not be a constant but may vary with respect to some other physical parameter. Various possible characterizations of Newton’s gravitational parameter as a function of the cosmic scale parameter are proposed and studied within the framework of classical Newtonian cosmology. A number of toy cosmologies with varying Newtonian gravitational parameters are developed and analyzed. The numerical solutions to the temporal evolution of the universe from the Friedmann equation are examined and discussed as well as kinematic observables. Finally, other avenues of research are addressed.

关键词： Newton’s Gravitation Constant Cosmology Fundamental Constants

EBSD Investigation on Effect of Cooling Rate on Microstructure and Transformation Textures of High Strength Hot-rolled Steel Plates

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Journal of Iron and Steel Research(International) 2016年第3期23卷 261-269页

作者： Nancy M.LOPEZ GRANADOS armando SALINAS RODRIGUEZ Department of Metallurgical Engineering and Materials Science Center of Research and Advanced StudiesCINVESTAV-Unidad Saltillo

The effect of cooling rate on the microstructure and transformation textures of high strength hot-rolled steels was *** treated samples subjected to different cooling conditions were characterized by optical and scanning electron microscopes using orientation imaging microscopy（OIM）.The experimental results demonstrate that there is a significant effect of cooling rate on microstructures and textures resulting from phase *** cooling rates lead to the appearance of the cube（001）[010],rotated cube（001）[110]/（001）[110],Goss（110）[001]and rotated Goss（110）[110]*** contrast,textures developed at rapid cooling rates are preferably of Cu（112）[111],Br（110）[112],transformed Cu（113）[110]and transformed Br（332）[113]/（112）[131].These texture changes are attributed to the selective character of the phase *** OIM technique was used to have a better understanding of the formation of phases and their relationship between microstructure and processing *** volume fraction of micro-constituents resulting from phase transformation such as bainite,martensite and different types of ferrite,can be measured satisfactorily by this technique correlating image quality of EBSD patterns to specific phases.

关键词： orientation imaging microscopy texture phase transformation microstructure steel

Dynamics of lossless polarization attraction

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Photonics Research 2015年第5期3卷 229-233页

作者： Matteo Barozzi armando Vannucci Dipartimento di Ingegneria Dell’Informazione Università degli Studi di Parma

We study a nonlinear lossless polarizer(NLP), a fiber-based device able to control the polarization of an optical signal while preserving its energy. The NLP exploits the lossless polarization attraction(LPA) generated by the Kerr interactions between the signal and a fully polarized continuous wave(CW) pump. By employing a copropagating pump, we show that the effectiveness of LPA depends on the joint action of the Kerr nonlinearity and the mutual delay between signal and pump. We find the optimal pump wavelength placement and demonstrate that true LPA occurs only within a limited range of delay values. Thus, we explain why the copropagating NLP is more flexible and power efficient compared with the traditional counterpropagating NLP.

关键词： SOP DOP NLP LPA

Effect of Different Reinforcing Fillers on Properties,Interfacial Compatibility and Weatherability of Wood-plastic Composites

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Journal of Bionic Engineering 2019年第2期16卷 337-353页

作者： Xiaoqian Wang Zhiming Yu armando G.McDonald MOE Key Laboratory of Wooden Material Science and Application Beijing Forestry UniversityQinghua East Road No.35Beijing 100083China Renewable Materials Program Department of ForestRangelandand Fire SciencesUniversity of Idaho875 Perimeter Drive MS 1133MoscowIdaho 83844-1133USA

Utilization of biochar in plastic based blends offers a sustainable way to renewable materials as well as value-added use of wood *** investigate the interfacial compatibility and weatherability properties of biochar composites,four types of Wood-Plastic Composites(WPC)were prepared by an extrusion *** mechanical properties,water absorptions,thermal and viscoelastic properties,and rheological behavior of the composites were also *** decolorizing carbon(NA)composite melts showed the higher modulus and viscosity,indicating better melt *** NA composites performed the best in tensile properties(strength of 2&6 MPa and modulus of 3.4 GPa)and had strong interfacial interaction between particles and the *** degree of HDPE crystallinity in the biochar and carbon composites decreased relative to Douglas-fir(DF)composites,while the thermal properties of the composites improved compared with DF *** the water resistance,the DF composites displayed the highest water absorption(3.7%)and thickness swell(2.9%).During accelerated weathering tests,longer exposure time increased the color change and lightness,especially for DF *** and biochar composites resulted in improved *** study opens up a pathway to utilize effectively the renewable biochar as reinforcing filler in WPC in outdoor applications.

关键词： biochar interfacial compatibility accelerated weathering wood-plastic composites

Addition of Urban Waste to Semiarid Degraded Soil:Long-term Effect

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Pedosphere 2007年第5期17卷 557-567页

作者： F.bastida J.L.MORENO C.GARC■A T.HERNNDEZ Department of Soil and Water Conservation Centro de Edafologia y Biologia Aplicada del Segura (CEBAS-CSIC) Campus Universitario de Espinardo30100 EspinardoMurcia (Spain).

The addition of municipal solid wastes (MSW) is considered as a possible strategy for soil rehabilitation in southeast *** objective of this study was to evaluate the long-term (17 years) effect of five doses of MSW addition on the microbiological,biochemical,and physical properties of semiarid *** values of several parameters that serve as indicators of general microbiological activity,such as,basal respiration,adenosine triphosphate (ATP) or dehydrogenase activity;microbial population size (microbial biomass C),and extracellular hydrolase activity related to macronutrient cycles,such as,urease,β-glucosidase,and N-α-benzoyl-L-argininamide protease,were observed in the amended *** highest MSW doses showed the highest values in these hydrolase *** incorporation of municipal waste resulted in a more dense development of the plant cover,50% greater in higher doses than in the control treatment,which generated a substantial increase in several C *** organic carbon reached 12 g kg^(-1) soil with the highest MSW doses, compared to 4.30 g kg^(-1) soil in the control *** physical properties of the soil were also improved,showing greater percentage of stable aggregates and water holding *** correlation coefficients between C fractions and parameters related to microbial activity and aggregate stability were *** these improvements were greater in the soils receiving the highest doses of organic amendment,the increases were not proportional to the amount added,demonstrating the existence of a threshold,above which an increase in the amount of organic matter added is not reflected in an increase in the soil's physical,biochemical,and microbiological ***,the addition of municipal solid wastes proved its suitability for improving soil quality,thereby indicating the potential of such an amendment,to prevent desertification in Mediterranean areas such as those studied.

关键词：半干旱退化土酶活力长期效应微生物量城市固体废物

Simulation of Bipolar Charge Transport in Graphene by Using a Discontinuous Galerkin Method

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Communications in Computational Physics 2019年第6期26卷 114-134页

作者： armando Majorana Giovanni Nastasi Vittorio Romano Department of Mathematics and Computer Science Universita degli Studi di Cataniaviale Andrea Doria 695125 CataniaItaly

Charge transport in suspended monolayer graphene is simulated by a numerical deterministic approach,based on a discontinuous Galerkin(DG)method,for solving the semiclassical Boltzmann equation for *** the conduction and valence bands are included and the interband scatterings are taken into *** use of a Direct Simulation Monte Carlo(DSMC)approach,which properly describes the interband scatterings,is computationally very expensive because the va-lence band is very populated and a huge number of particles is *** the choice of simulating holes instead of electrons does not overcome the problem because there is a certain degree of ambiguity in the generation and recombination terms of electron-hole ***,direct solutions of the Boltzmann equations with a DSMC neglect the interband scatterings on the basis of physical *** DG approach does not suffer from the previous drawbacks and requires a reasonable computing *** the present paper the importance of the interband scatterings is accurately evaluated for several values of the Fermi energy,addressing the issue related to the validity of neglecting the generation-recombination *** is found out that the inclusion of the interband scatterings produces huge variations in the average values,as the current,with zero Fermi energy while,as expected,the effect of the interband scattering becomes negligible by increasing the absolute value of the Fermi energy.

关键词： Graphene bipolar charge transport discontinuous Galerkin method

Helicobacter Pylori Infection and Lung Cancer： New Insights and Future Challenges

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中国肺癌杂志 2018年第9期21卷 658-662页

作者： Ileana GONZALEZ Paulina ARAYA armando ROJAS Biomedical Research Laboratories Medicine Faculty Catholic University of Maule Talca Chile

Helicobacter pylori(H. pylori) is the causative agent of chronic gastritis and peptic ulcer diseases and is an important risk factor for the development functional dyspepsia, peptic ulceration, gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma. H. pylori has very high rates of infection in human populations, and it is estimated that over 50% of the world population is infected. Recently, certain extra-gastric manifestations, linked to H. pylori infection, have been widely investigated. Noteworthy, a growing body of evidences supports an association between H. pylori infection with lung cancer. The present review intend to highlight not only the most recent evidences supporting this association, but also some missed points, which must be considered to validate this emerging association.

关键词：幽门螺杆菌慢性胃炎治疗方法临床分析