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A Quasilinear System Related with the Asymptotic Equation of the Nematic Liquid Crystal’s Director Field

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Chinese Annals of Mathematics,Series B 2021年第2期42卷 163-172页

作者： João-Paulo DIAS Departamento de Matemática and CMAFcIo Faculdade de Ciências da Universidade de LisboaCampo GrandeEdificio C61749-016 LisboaPortugal

In this paper, the author studies the local existence of strong solutions and their possible blow-up in time for a quasilinear system describing the interaction of a short wave induced by an electron field with a long wave representing an extension of the motion of the director field in a nematic liquid crystal’s asymptotic model introduced in[Saxton, R. A., Dynamic instability of the liquid crystal director. In: Current Progress in Hyperbolic Systems(Lindquist, W. B., ed.), Contemp. Math., Vol.100, Amer. ***., Providence, RI, 1989, pp.325–330] and [Hunter, J. K. and Saxton, R. A., Dynamics of director fields, SIAM J. Appl. Math., 51, 1991, 1498–1521] and studied in [Hunter, J. *** Zheng, Y., on a nonlinear hyperbolic variational equation I, Arch. Rat. Mech. Anal.,129, 1995, 305–353], [Hunter, J. K. and Zheng, Y., on a nonlinear hyperbolic variational equation II, Arch. Rat. Mech. Anal., 129, 1995, 355–383] and in [Zhang, P. and Zheng,Y., on oscillation of an asymptotic equation of a nonlinear variational wave equation,Asymptotic Anal., 18, 1998, 307–327] and, more recently, in [Bressan, A., Zhang, P. and Zheng, Y., Asymptotic variational wave equations, Arch. Rat. Mech. Anal., 183, 2007,163–185].

关键词： Benney system Conservation law Schrödinger equation Nematic liquid crystal Director field

Stability analysis of a time-delayed Van der Pol–Helmholtz–Duffing oscillator in fractal space with a non-perturbative approach

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Communications in Theoretical Physics 2024年第4期76卷 22-31页

作者： Yusry o El-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The time-delayed fractal Van der Pol–Helmholtz–Duffing(VPHD)oscillator is the subject of this paper,which explores its mechanisms and highlights its stability *** time-delayed technologies are currently garnering significant attention,the focus of this research remains crucially relevant.A non-perturbative approach is employed to refine and set the stage for the system under *** innovative methodologies introduced yield an equivalent linear differential equation,mirroring the inherent nonlinearities of the ***,the incorporation of quadratic nonlinearity into the frequency formula represents a cutting-edge *** analytical solution's validity is corroborated using a numerical *** conditions are ascertained through the residual Galerkin ***,it is observed that the delay parameter,in the context of the fractal system,reverses its stabilizing influence,impacting both the amplitude of delayed velocity and the *** analytical solution's precision is underscored by its close alignment with numerical ***,the study reveals that fractal characteristics emulate damping *** its applicability across diverse nonlinear dynamical systems,this non-perturbative approach emerges as a promising avenue for future research.

关键词： Van der Pol-Helmholtz-Duffing oscillator fractal space time-delay non-perturbative approach stability analysis El-Dib's frequency formula

Montology manifesto:echoes towards a transdisciplinary science of mountains

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Journal of Mountain Science 2020年第10期17卷 2512-2527页

作者： Fausto o.SARMIENTo Neotropical Montology Collaboratory Department of GeographyUniversity of GeorgiaAthensGeorgia30602USA

Mountains as archetype frame some metageographies of the vertical *** metaphors,thus,have remained as key guidance in developing not only animistic belief systems and religious cults,but also military strategies,economic potential,and scientific *** paper seeks to explain the need to integrate western knowledge,where mountains became known via natural history’s mechanistic explanations,with other *** scientists therein developed linear approaches that required exploration,experimentation,and pragmatic interpretation of generalizable mountain *** is known,however,about other civilizations’more encompassing cognition due to heuristic explanations of mountain *** knowledge holders therein developed approaches that required familiarization,observation,and romantic meditation about situated mountain *** a multimethod approach of human geography that includes onomastics,geocritical discourse analysis,political ecology,and critical biogeography,the author posits that there is a paradigmatic shift of geographic fad,when even"nature"is thought of as a"social construct"in the socioecological *** these tendencies of either Cartesian or Spinozan dogmas about scientific objectives,methods and implications,mountains continue to elicit geographical *** author thus concludes that integrating narratives of mountain studies with geocritical analyses of political ecology that allow for transgressivity and referentialilty of mountain cognition can be done with transdisciplinary ***,henceforth,couples dialectic thinking with the trifecta of spatiality,complexity and historicity in highlighting mountain microrefugia for biocultural *** of montological approaches will bring mountain scientists to a new level,where the application of local ecological knowledge and cutting-edge technological instrumentation could render sustainable mountain communities,in dy

关键词： Montology Geocriticism Biocultural Heritage Transdisciplinarity Mountain cognition Mountainscape

An efficient approach to solving fractional Van der Pol-Duffing jerk oscillator

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Communications in Theoretical Physics 2022年第10期74卷 50-59页

作者： Yusry o El-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The motive behind the current work is to perform the solution of the Van der Pol–Duffing jerk oscillator,involving fractional-order by the simplest *** effective procedure has been introduced for executing the fractional-order by utilizing a new method without the perturbative *** approach depends on converting the fractional nonlinear oscillator to a linear oscillator with an integer order.A detailed solving process is given for the obtained oscillator with the traditional system.

关键词： Van der Pol oscillator Duffing jerk oscillator fractional oscillator non-perturbative approach numerical simulation

Federalism and Euro-Regions in Europe： What Have We Learned From Twenty-Five Years of Cross-Border Cooperation in the Euro-region of Galicia-North Portugal？

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International Relations and Diplomacy 2016年第4期4卷 261-278页

作者： Argimiro Rojo Salgado Enrique Jose varela Alvarez University of Vigo Pontevedra Spain

The present paper is focused on the analysis of the European building processes from the historical perspective of federalism （from ethnic federalism to current federalism） applied to the current framework of Europeanization and cross-border cooperation in Europe. With the objective of reviewing some of its processes and impacts, an analysis structure has been set, being the main purpose to extract conclusions on the long Europeanization process undertaken by the EU institutions. one of these recent processes reached the consolidation of Euroregions as cross-border cooperation institutions within the framework of multilevel governance. For the main purpose of the paper, the following questions are raised： How has contributed the perspective of federalism to the building of cross-border institutions, namely Euroregions？ After three decades of implementation of the formal cooperation in Europe through institutions as the Euroregions, can it be confirmed that the Eurnregions are consolidated as an institutional benchmark within the cross-border cooperation in Europe （CBC-E）？ In order to answer these questions, a review of the historic perspective of ethnic federalism applied to the classical models of formal cooperation is undertaken. From this historical revision, the development of the Euroregion within the EU will be analyzed. Finally, the present paper is focused on the case study of the cross-border space that are the Autonomous Region of Galician and the Regiao Norte de Portugal, as well as its most important cooperative institution, the Euro-region Galicia-North Portugal.

关键词： European integration ethnic federalism cross-border cooperation Euro-regions Galicia-North Portugal

Differential degradation of crude oil (Bonny Light) by four Pseudomonas strains

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Journal of Environmental Sciences 2009年第2期21卷 243-248页

作者： oluwafemi S.obayori Sunday A.Adebusoye Adams o.Adewale Ganiyu o.oyetibo odunola o.oluyemi Rashid A.Amokun Matthew o.Ilori Department of Microbiology Lagos State University Department of Botany and Microbiology University of Lagos

Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials. All the isolates were identified as species of Pseudomonas. Pseudomonas putida P 11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P. aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene. Pseudomonas putida WL2 and P. aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11. All the strains grew logarithmically with 1-2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence. Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period. BB3 on the other hand degraded only 46% within 6 d. Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks （including aliphatics and aromatics） in the hydrocarbon mixture.

关键词： biodegradation crude oil hydrocarbons pollution Pseudomonas strains

Effect of Ceo_2 and Al_2o_3 on the activity of Pd/Co_3o_4/cordierite catalyst in the three-way catalysis reactions(Co/No/C_nH_m)

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Journal of Environmental Sciences 2012年第7期24卷 1327-1333页

作者： Sergiy o.Soloviev Pavlo I.Kyriienko Nataliia o.Popovych L.V.Pisarzhevsk Institute of Physical Chemistry National Academy of Sciences of Ukraine

The present article studies the effect of Ceo2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of No, Co, CnHm. The catalysts were characterized by temperature programmed reduction with hydrogen, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It is shown that the effect of Ceo2 on the properties of Pd/C03 o4/cordierite catalyst depends on preparation method. The catalyst obtained by co-deposition of cerium and cobalt oxides has higher activity in Co oxidation （Co ＋ 02 and Co ＋ No） and total hexane oxidation （C6H14 ＋ 02）. Such phenomenon is probably caused by more than stoichiometric amount of formed oxygen vacancies, an increase in both mobility of surface oxygen and dispersity of components in the catalytic composition. It is demonstrated that Ceo2 addition promotes the So2 resistance of Pd/C03 o4/cordierite. The second support decreases the activity of Pd/Co3oa/cordierite catalyst in the reactions of Co and C6H14 with oxygen because of CoA1204 formation.

关键词： metal-oxide catalysts structured catalysts effect of Ceo2 and A1203 Co No CnH,. conversion

A risk assessment system for alien plant bio-invasion in Xiamen,China

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Journal of Environmental Sciences 2008年第8期20卷 989-997页

作者： Desmond K.o'TooLE Department of Biology and Chemistry City University of Hong Kong83 Tat Chee AveKowloonHong Kong SAR 999077China

Bio-invasion has caused serious ecosystem damage and enormous economic losses in China,and it has been the greatest factor to island bio-diversity ***,as an important seaport with a relatively high conservation value,is particularly vulnerable to bio-invasion for its typical island ecosystem as well as frequent human-made *** a result of field surveys,literature review, and consultation with experts,a list of 67 alien plants identified as major invaders(12 species)and emerging invade...

关键词： bio-invasion invasive species alien plants risk assessment

Effective simulation of flexible lateral boundaries in two-and three-dimensional DEM simulations

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Particuology 2008年第6期6卷 483-500页

作者： Geraldine Cheung Catherine o'Sullivan Department of Civil and Environmental Engineering Imperial College London

Discrete element method （DEM） models to simulate laboratory element tests play an important role in advancing our understanding of the mechanics of granular material response, including bonded or cemented, particulate materials. Comparisons of the macro-scale response observed in a real physical test and a ＂virtual＂ DEM-simulated test can calibrate or validate DEM models. The detailed, particle scale information provided in the DEM simulation can then be used to develop our understanding of the material behaviour. It is important to accurately model the physical test boundary conditions in these DEM simulations. This paper specifically considers triaxial tests as these tests are commonly used in soil mechanics. In a triaxial test, the test specimen of granular material is enclosed within a flexible latex membrane that allows the material to deform freely during testing, while maintaining a specified stress condition. Triaxial tests can only be realistically simulated in 3D DEM codes, however analogue, 2D, biaxial DEM simulations are also often considered as it is easier to visualize particle interactions in two dimensions. This paper describes algorithms to simulate the lateral boundary conditions imposed by the latex membrane used in physical triaxial tests in both 2D and 3D DEM simulations. The importance of carefully considering the lateral boundary conditions in DEM simulations is illustrated by considering a 2D biaxial test on a specimen of frictional unbonded disks and a 3D triaxial test on a bonded （cemented） specimen of spheres. The comparisons indicate that the lateral boundary conditions have a more significant influence on the local, particle-scale response in comparison with the overall macro-scale observations.

关键词： Triaxial testing Discrete element simulations Boundary conditions