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Trudinger–Moser Inequalities on a Closed Riemann Surface with a Symmetric Conical Metric

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2263-2284页

作者： Yu FANG Yun yan yang College of Teacher Education Quzhou UniversityQuzhou 324003P.R.China Department of Mathematics Renmin University of ChinaBeijing 100872P.R.China

This is a continuation of our previous work(*** ***.,20,1295–1324,2020).Let(Σ,g)be a closed Riemann surface,where the metric g has conical singularities at finite *** G is a group whose elements are isometries acting on(Σ,g).Trudinger–Moser inequalities involving G are established via the method of blow-up analysis,and the corresponding extremals are also *** extends previous results of Chen(***.,1990),Iula–Manicini(Nonlinear Anal.,2017),and the authors(2020).

关键词： Trudinger-Moser inequality blow-up analysis conical singularity

A UNIFIED A POSTERIORI ERROR ANALYSIS FOR DISCONTINUOUS GALERKIN APPROXIMATIONS OF REACTIVE TRANSPORT EQUATIONS

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Journal of Computational Mathematics 2006年第3期24卷 425-434页

作者： Ji-ming yang yan-ping Chen Hunan Key Laboratory for Computation and Simulation in Science and Engineering Institute for Computational and Applied Mathematics and School of Mathematics and Computing Science Xiangtan University Xiangtan 4 11105 China

Four primal discontinuous Galerkin methods are applied to solve reactive transport problems, namely, Oden-BabuSka-Baumann DG （OBB-DG）, non-symmetric interior penalty Galerkin （NIPG）, symmetric interior penalty Galerkin （SIPG）, and incomplete interior penalty Galerkin （IIPG）. A unified a posteriori residual-type error estimation is derived explicitly for these methods. From the computed solution and given data, explicit estimators can be computed efficiently and directly, which can be used as error indicators for adaptation. Unlike in the reference [10], we obtain the error estimators in L^2 （L^2） norm by using duality techniques instead of in L^2（H^1） norm.

关键词： A posteriori error estimates Duality techniques Discontinuous Galerkin methods

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Artist yang yan

ChinAfrica 2011年第7期3卷 54-54页

作者： yang yan

How would you describe splashed- ink painting? The painting process is like a volcanic eruption.I usually begin by "splashing" ink washes to define mountains,hills and other landscape elements,and then add finer details such as temples, boats,trees and people in darker ink with quick *** wisdom to have an overall grasp of things and the ability to control the ink-its density and flow,its depth and shallownessis very *** goes far beyond technique.

关键词： Artist yang yan

Conflict between wild boars(Sus scrofa) and farmers:distribution, impacts,and suggestions for management of wild boars in the Three Gorges Reservoir Area

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Journal of Mountain Science 2019年第10期16卷 2404-2416页

作者： LIU Qin yan Kun LU Ya-feng LI Ming yan yang-yang Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu610041China Wanzhou Key Regional Ecology and Environment Monitoring Station WanzhouChongqing404020China College of Earth Sciences Chengdu University of TechnologyChengdu610059China University of Chinese Academy of Sciences Beijing100049China

Economic losses caused by wild boars(Sus scrofa)continue to increase in the Three Gorges Reservoir *** selected 206 farmers in Wuqiaohe Basin as survey respondents using random stratified *** distribution and impacts of wild boars were examined using a questionnaire survey and spatial *** results showed that:(1)The density of farmer settlements is low and most peasants’households are located on the forest *** to large-scale labor migration,a high proportion of farmland(25.85%)has been abandoned and an even higher proportion of farmland(40.48%)has been returned to forest.(2)The probability of wild boar damage to peasant households was 67.96%.Yields of corn and sweet potato decreased by 24.87%and 28.24%,respectively,with a total economic loss of approximately 2,590,100 RMB/yr in the Wuqiaohe ***-five percent of the affected cultivatedlands were located within approximately 150 m of the forest edges.(3)The wild boar damage coefficient was significantly and negatively correlated with the distance between the peasants’household and the forest edge,the density of the settlements,and the area of cultivated *** wild boar damage coefficient shows a significant positive correlation with the area of farmland returned to forest.(4)The damage activity caused by wild boars began to occur7-8 years ago,and the destruction has been more frequently and seriously observed in the last 4-5 years.(5)We make suggestions for wild boar control and management measures including developing a compensation *** compensation standard is related to the land area returning from farmland to forests and the actual cultivated land area.

关键词： Distribution features Economic loss Management Three Gorges Reservoir Area Wild boar

Bifurcations and Chaos in Mira 2 Map

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Acta Mathematicae Applicatae Sinica 2017年第4期33卷 967-978页

作者： Tao JIANG Zhi-yan yang School of Information Beijing Wuzi University Beijing 101149 China

In this paper, Mira 2 map is investigated. The conditions of the existence for fold bifurcation, flip bifurcation and Naimark-Sacker bifurcation are derived by using center manifold theorem and bifurcation theory. And the conditions of the existence for chaos in the sense of Marroto are obtained. Numerical simulation results not only show the consistence with the theoretical analysis but also display complex dynamical behaviors, including period-n orbits, crisis, some chaotic attractors, period-doubling bifurcation to chaos, quasi-period behaviors to chaos, chaos to quasi-period behaviors, bubble and onset of chaos.

关键词： Mira 2 map fold bifurcation flip bifurcation Naimark-Sacker bifurcation chaos in the sense ofMarroto

The Same Distribution of Limit Cycles in a Hamiltonian System with Nine Seven-order Perturbed Terms

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Acta Mathematicae Applicatae Sinica 2008年第1期24卷 167-176页

作者： Tao Jiang Zhi-yan yang School of Information Beijing Wuzi University Beijing 101149 China

Using qualitative analysis and numerical simulation, we investigate the number and distribution of limit cycles for a cubic Hamiltonian system with nine different seven-order perturbed terms. It is showed that these perturbed systems have the same distribution of limit cycles. Furthermore, these systems have 13, 11 and 9 limit cycles for some parameters, respectively. The accurate positions of the 13, 11 and 9 limit cycles are obtained by numerical exploration, respectively. Our results imply that these perturbed systems are equivalent in the sense of distribution of limit cycles. This is useful for studying limit cycles of perturbed systems.

关键词： Limit cycles bifurcation

Determination of Cationic Surfactant by Laser Thermal Lens Spectrometry

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Chinese Chemical Letters 2002年第11期13卷 1107-1110页

作者： Hong Tao yan Ying ZHANG yang yan Department of Chemistry Northwest UniversityXian 710069

A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfonic acid (5-NO2-PAH) and cationic surfactant to form 1:2 ionic association complex in a weakly basic medium (pH 9.44). The determination conditions and the mechanism were discussed. The method has been applied to the analysis of wastewater and moat water samples.

关键词： Determination of cationic surfactant cetylpyridinium bromide (CPB) cetyltri- methyl-ammonium bromide (CTMAB) 1-hydroxy-2-(5-nitro-2-pyridylazo)-8-aminonaphthalene- 3,6-disulfonic acid (5-NO2-PAHA) laser thermal lens spectrometry.

A C^0-WEAK GALERKIN FINITE ELEMENT METHOD FOR THE TWO-DIMENSIONAL NAVIER-STOKES EQUATIONS IN STREAM-FUNCTION FORMULATION

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Journal of Computational Mathematics 2020年第2期38卷 310-336页

作者： Baiju Zhang yan yang Minfu Feng School of Mathematics Sichuan UniversityChengdu 610064China School of Sciences Southwest Petroleum UniversityChengdu 610500China

We propose and analyze a C^0-weak Galerkin(WG)finite element method for the numerical solution of the Navier-Stokes equations governing 2D stationary incompressible *** a st ream-function formulation,the system of Navier-Stokes equations is reduced to a single fourth-order nonlinear partial differential equation and the incompressibility constraint is automatically *** proposed method uses continuous piecewisepolynomial approximations of degree k+2 for the stream-function 0 and discontinuous piecewise-polynomial approximations of degreek+1 for the trace of V-0 on the interelement *** existence of a discrete solution is proved by means of a topological degree argument,while the uniqueness is obtained under a data smallness *** optimal error estimate is obtained in L^2-norm,H^1-norm and brokenH^*** tests are presented to demonstrate the theoretical results.

关键词： Weak Galerkin method Navier-S to kes equations St ream-function formulation.

Long-term optical color behavior of a sample of blazars

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Research in Astronomy and Astrophysics 2018年第12期18卷 67-74页

作者： Xiao-Pan Li Yu-Hui Luo Hai-Tao yang Hai-yan yang Cheng yang yan Cai College of Physics and Information Engineering Zhaotong University College of Photoelectron and Communication Engineering Yunnan Open University

We report on the optical color variability of a sample of 24 blazars, consisting of nine flat spectrum radio quasars(FSRQs) and 15 BL Lacertae objects(BL Lacs), on timescales of years using simultaneous V-and R-band observations observed by the Kanata telescope at Higashi-Hiroshima *** correlations between color indices V-R and magnitudes reveal that 11 BL Lacs and one FSRQ exhibited significant(i.e., r > 0.2 and P < 0.01) bluer-when-brighter(BWB) trend and two FSRQs followed the redder-when-brighter(RWB) tend, indicating a possibility that the BWB chromatic trend is dominant for BL Lacs and the RWB trend is especially found in FSRQs, which has been presented occasionally in different samples of *** superpositions of the red emission component from the Doppler-boosted relativistic jet and the blue component arising from the accretion disk might be a possible interpretation for the long-term color behaviors.

关键词： galaxies:active BL Lacertae objects:general quasars:general methods:statistical