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Bounded and Unbounded Solutions of the SD Oscillator at Resonance
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作者 Bian Jingke Liu Jie 《数学理论与应用》 2024年第4期45-69,共25页
In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f... In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f(x)≠0,the system is non-Hamiltonian,so we have to introduce some reversibility assumptions to apply a suitable twist theorem,for reversible maps with small twist.Moreover,when the nonnegative parameterαdecreases to 0,the system becomes discontinuous.In this case,we need to introduce some suitable transformations to overcome the lack of regularity.We will prove that for any nonnegative parameterα,when p(t)is an odd periodic function satisfying∣∣∫2π0p(t)sintdift∣∣<4,all the solutions are bounded;when p(t)satisfies∣∣∫2π0p(t)sintdift∣∣>4,the SD oscillator has unbounded solutions,and when p(t)satisfies∣∣∫_(0)^(2π)p(t)sintdift∣∣≥4+|F|_(∞),all the solutions are unbounded. 展开更多
关键词 SD oscillator Reversible system bounded solution Unbounded solution
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Kangfuxin solution alleviates esophageal stenosis after endoscopic submucosal dissection:A natural ingredient strategy
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作者 Xin Zhou Dan Ma +7 位作者 Yi-Xiang He Jing Jin Hong-Lian Wang Yun-Feng Wang Fan Yang Jian-Qin Liu Jie Chen Zhi Li 《World Journal of Gastroenterology》 SCIE CAS 2025年第1期110-125,共16页
BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.... BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway. 展开更多
关键词 Kangfuxin solution Natural component Endoscopic submucosal dissection Esophagus stricture Fibrosis
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Normalized Solutions of Nonlinear Choquard Equations with Nonconstant Potential
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作者 LI Nan XU Liping 《应用数学》 北大核心 2025年第1期14-29,共16页
In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with ... In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with prescribed 2-norm has some normalized solutions by introducing variational methods. 展开更多
关键词 Nonlinear Choquard equation Potential function Variational method Normalized solution
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The Exact Limits and Improved Decay Estimates for All Order Derivatives of the Global Weak Solutions of n-Dimensional Incompressible Navier-Stokes Equations
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作者 Ling-hai ZHANG 《Acta Mathematicae Applicatae Sinica》 2025年第1期27-83,共57页
We couple together existing ideas,existing results,special structure and novel ideas to accomplish the exact limits and improved decay estimates with sharp rates for all order derivatives of the global weak solutions ... We couple together existing ideas,existing results,special structure and novel ideas to accomplish the exact limits and improved decay estimates with sharp rates for all order derivatives of the global weak solutions of the Cauchy problem for an n-dimensional incompressible Navier-Stokes equations.We also use the global smooth solution of the corresponding heat equation to approximate the global weak solutions of the incompressible Navier-Stokes equations. 展开更多
关键词 the incompressible Navier-Stokes equations global smooth solution global weak solutions local smooth solutions all order derivatives special structure novel ideas primary decay estimates with sharp rates exact limits improved decay estimates with sharp rates influence on numerical simulations
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Riemann-Hilbert Problem and Multiple High-order Poles Solutions of the Focusing mKdV Equation with Nonzero Boundary Conditions
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作者 Zi-yi WANG Shou-fu TIAN Jin-jie YANG 《Acta Mathematicae Applicatae Sinica》 2025年第1期234-251,共18页
The focusing modified Korteweg-de Vries(mKdV)equation with multiple high-order poles under the nonzero boundary conditions is first investigated via developing a Riemann-Hilbert(RH)approach.We begin with the asymptoti... The focusing modified Korteweg-de Vries(mKdV)equation with multiple high-order poles under the nonzero boundary conditions is first investigated via developing a Riemann-Hilbert(RH)approach.We begin with the asymptotic property,symmetry and analyticity of the Jost solutions,and successfully construct the RH problem of the focusing mKdV equation.We solve the RH problem when 1/S_(11)(k)has a single highorder pole and multiple high-order poles.Furthermore,we derive the soliton solutions of the focusing mKdV equation which corresponding with a single high-order pole and multiple high-order poles,respectively.Finally,the dynamics of one-and two-soliton solutions are graphically discussed. 展开更多
关键词 Riemann-Hilbert approach focusing mKdV equation nonzero boundary conditions multiple high-order poles soliton solutions
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THE BASIC THEORY OF SOLUTIONS OF FUNCTIONAL DIFFERENTIAL EQUATIONS WITH BOUNDED DELAY IN THE SPACE OF INTEGRABLE FUNCTIONS
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作者 刘永清 李远清 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 1997年第7期67-73,共7页
在可积函数空间中讨论有界滞量泛函微分方程,建立其解的基本理论,包括解的存在性,唯一性及延展性。
关键词 有界滞量的泛函微分方程 存在性 唯一性 延展性 可积函数空间
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Wave packet solutions in a bounded equatorial ocean and its interannual and decadal variabilities 被引量:3
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作者 Dongling Zhang Juan Zhu +1 位作者 Xu Lu Ming Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第3期45-59,共15页
Linearized shallow water perturbation equations with approximation in an equatorial β plane are used to obtain the analytical solution of wave packet anomalies in the upper bounded equatorial ocean. The main results ... Linearized shallow water perturbation equations with approximation in an equatorial β plane are used to obtain the analytical solution of wave packet anomalies in the upper bounded equatorial ocean. The main results are as follows. The wave packet is a superposition of eastward travelling Kelvin waves and westward travelling Rossby waves with the slowest speed, and satisfies the boundary conditions of eastern and western coasts, respectively.The decay coefficient of this solution to the north and south sides of the equator is inversely proportional only to the phase velocity of Kelvin waves in the upper water. The oscillation frequency of the wave packet, which is also the natural frequency of the ocean, is proportional to its mode number and the phase velocity of Kelvin waves and is inversely proportional to the length of the equatorial ocean in the east-west direction. The flow anomalies of the wave packet of Mode 1 most of the time appear as zonal flows with the same direction. They reach the maximum at the center of the equatorial ocean and decay rapidly away from the equator, manifested as equatorially trapped waves. The flow anomalies of the wave packet of Mode 2 appear as the zonal flows with the same direction most of the time in half of the ocean, and are always 0 at the center of the entire ocean which indicates stagnation, while decaying away from the equator with the same speed as that of Mode 1. The spatial structure and oscillation period of the wave packet solution of Mode 1 and Mode 2 are consistent with the changing periods of the surface spatial field and time coefficient of the first and second modes of complex empirical orthogonal function(EOF)analysis of flow anomalies in the actual equatorial ocean. This indicates that the solution does exist in the real ocean, and that El Ni?o-Southern Oscillation(ENSO) and Indian Ocean dipole(IOD) are both related to Mode 2.After considering the Indonesian throughflow, we can obtain the length of bounded equatorial ocean by taking the sum of that of the tropical Indian Ocean and the tropical Pacific Ocean, thus this wave packet can also explain the decadal variability(about 20 a) of the equatorial Pacific and Indian Oceans. 展开更多
关键词 bounded EQUATORIAL OCEAN WAVE packet solutionS DECADAL variability Kelvin WAVE Rossby WAVE
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Continuous Dependence of Bounded Φ-variation Solutions on Parameter for a Class of Discontinuous Systems 被引量:2
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作者 马学敏 李宝麟 林长伟 《Chinese Quarterly Journal of Mathematics》 2015年第4期610-619,共10页
The functions of bounded φ-variation are development and generalization of bounded variation functions in the usual sense.Henstock-Kurzweil integral is a very useful tool for some discontinuous systems. In this paper... The functions of bounded φ-variation are development and generalization of bounded variation functions in the usual sense.Henstock-Kurzweil integral is a very useful tool for some discontinuous systems. In this paper, by using Henstock-Kurzweil integral, we establish theorems of continuous dependence of bounded D-variation solutions on parameter for a class of discontinuous systems on the base of D-function. These results are essential generalizations of continuous dependence of bounded variation solutions on parameter for the systems. 展开更多
关键词 discontinuous systems Henstock-Kurzweil integral bounded Φ-variation solution continuous dependence
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Continuous Dependence of Bounded Φ-Variation Solutions on Parameters for Kurzweil Equations 被引量:3
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作者 李宝麟 吴从炘 《Northeastern Mathematical Journal》 CSCD 2005年第4期421-430,共10页
The continuous dependence of bounded Φ-variation solutions on parameters for Kurzweil equations are established by using the functions of bounded Φ- variation that were introduced by Musielak-Orlice. These results a... The continuous dependence of bounded Φ-variation solutions on parameters for Kurzweil equations are established by using the functions of bounded Φ- variation that were introduced by Musielak-Orlice. These results are essential generalizations of continuous dependence of bounded variation solutions on parameters for Kurzweil equations. 展开更多
关键词 Kurzweil equation bounded Φ-variation solution continuous dependence on parameter
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GLOBALLY BOUNDED IN-TIME SOLUTIONS TO A PARABOLIC-ELLIPTIC SYSTEM MODELLING CHEMOTAXIS 被引量:3
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作者 钟新华 江松 《Acta Mathematica Scientia》 SCIE CSCD 2007年第2期421-429,共9页
In this article, the globally bounded in-time pointwise estimate of solutions to the simplified Keller-Segel system modelling chemotaxis are derived. Moreover, a local existence theorem is obtained.
关键词 Keller-Segel system CHEMOTAXIS globally bounded
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Vertex solution theorem for the upper and lower bounds on the dynamic response of structures with uncertain-but-bounded parameters 被引量:4
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作者 Zhiping Qiu Xiaojun Wang Institute of Solid Mechanics, Beihang University, 100083 Beijing, China 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第3期367-379,共13页
The aim of this paper is to evaluate the effects of uncertain-but-bounded parameters on the dynamic response of structures. By combining the interval mathematics and the finite element analysis, the mass matrix, dampi... The aim of this paper is to evaluate the effects of uncertain-but-bounded parameters on the dynamic response of structures. By combining the interval mathematics and the finite element analysis, the mass matrix, damping matrix, stiffness matrix and the external loads are represented as interval matrices and vector. With the help of the optimization theory, we present the vertex solution theorem for determining both the exact upper bounds or maximum values and the exact lower bounds or minimum values of the dynamic response of structures, in which these parameters reach their extreme values on the boundary of the interval mass, damping, stiffness matrices and the interval extemal loads vector. Three examples are used to illustrate the computational aspects of the presented vertex solution theorem. 展开更多
关键词 Dynamic response Vertex solution theorem Uncertain-but-bounded parameters
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Globally Bounded Solutions in A Chemotaxis Model of Quasilinear Parabolic Type 被引量:1
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作者 LIU Bing-chen DONG Meng-zhen 《Chinese Quarterly Journal of Mathematics》 2019年第3期274-282,共9页
In this paper,we consider a quasilinear parabolic-parabolic chemotaxis model with nonlinear diffusivity,aggregation and logistic damping source:■where k1 epu≤D(u) or k1 up≤D(u);k2 equ≤S(u)≤k3 equ;g(u)≤a-... In this paper,we consider a quasilinear parabolic-parabolic chemotaxis model with nonlinear diffusivity,aggregation and logistic damping source:■where k1 epu≤D(u) or k1 up≤D(u);k2 equ≤S(u)≤k3 equ;g(u)≤a-beku.It is proved that,if q <k-1 or q=k-1 and b> b0 for some constant b0> 0,then there exists a unique classical solution which is globally bounded.The results show the effect of the aggregation and the logistic damping source on the existence of globally bounded solutions. 展开更多
关键词 CHEMOTAXIS Nonlinear DIFFUSIVITY AGGREGATION LOGISTIC Type Damping Globally bounded solution
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Analytical solutions for constant-rate test in bounded confined aquifers with non-Darcian effect 被引量:2
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作者 Yi-jie Zong Li-hua Chen +4 位作者 Jian-jun Liu Yue-hui Liu Yong-xin Xu Fu-wan Gan Liang Xiao 《Journal of Groundwater Science and Engineering》 2022年第4期311-321,共11页
This paper proposes a simplified analytical solution considering non-Darcian and wellbore storage effect to investigate the pumping flow in a confined aquifer with barrier and recharge boundaries.The mathematical mode... This paper proposes a simplified analytical solution considering non-Darcian and wellbore storage effect to investigate the pumping flow in a confined aquifer with barrier and recharge boundaries.The mathematical modelling for the pumping-induced flow in aquifers with different boundaries is developed by employing image-well theory with the superposition principle,of which the non-Darcian effect is characterized by Izbash’s equation.The solutions are derived by Boltzmann and dimensionless transformations.Then,the non-Darcian effect and wellbore storage are especially investigated according to the proposed solution.The results show that the aquifer boundaries have non-negligible effects on pumping,and ignoring the wellbore storage can lead to an over-estimation of the drawdown in the first 10 minutes of pumping.The higher the degree of non-Darcian,the smaller the drawdown. 展开更多
关键词 Non-Darcian effect bounded aquifer Wellbore storage Izbash’s equation Analytical solution
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FORMULA OF GLOBAL SMOOTH SOLUTION FOR NON-HOMOGENEOUS M-D CONSERVATION LAW WITH UNBOUNDED INITIAL VALUE 被引量:1
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作者 曹高伟 胡凯 杨小舟 《Acta Mathematica Scientia》 SCIE CSCD 2015年第2期508-526,共19页
In this article, we prove the existence and obtain the expression of its solution formula of global smooth solution for non-homogeneous multi-dimensional(m-D) conservation law with unbounded initial value; our metho... In this article, we prove the existence and obtain the expression of its solution formula of global smooth solution for non-homogeneous multi-dimensional(m-D) conservation law with unbounded initial value; our methods are new and essentially different with the situation of bounded initial value. 展开更多
关键词 solution formula non-homogeneous m-D conservation laws global smooth solution global implicit function
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ON SOLUTIONS OF BACKWARD STOCHASTIC DIFFERENTIAL EQUATIONS WITH JUMPS,WITH UNBOUNDED STOPPING TIMES AS TERMINAL AND WITH NON-LIPSCHITZ COEFFICIENTS,AND PROBABILISTIC INTERPRETATION OF QUASI-LINEAR ELLIPTIC TYPE INTEGRO-DIFFERENTIAL EQUATIO 被引量:1
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作者 司徒荣 王越平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第6期659-672,共14页
The existence and uniqueness of solutions to backward stochastic differential equations with jumps and with unbounded stopping time as terminal under the non_Lipschitz condition are obtained. The convergence of soluti... The existence and uniqueness of solutions to backward stochastic differential equations with jumps and with unbounded stopping time as terminal under the non_Lipschitz condition are obtained. The convergence of solutions and the continuous dependence of solutions on parameters are also derived. Then the probabilistic interpretation of solutions to some kinds of quasi_linear elliptic type integro_differential equations is obtained. 展开更多
关键词 backward stochastic differential equations(BSDEs) with jumps unbounded stopping time adapted solutions convergence of solutions quasi_linear elliptic equations integro_differential operators.
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BOUNDEDNESS PROPERTIES OF SOLUTIONS OF DOUBLY NONLINEAR PARABOLIC EQUATIONS 被引量:1
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作者 梁学信 《Acta Mathematica Scientia》 SCIE CSCD 1994年第S1期110-117,共8页
Consider a doubly nonlinear parabolic equation and prove the boundedness of its generalized solutions.
关键词 Doubly nonlinear perabelic equation Generalized solution Local and global boundedness.
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MULTIPLE POSITIVE SOLUTIONS OF INHOMOGENEOUS SEMILINEAR ELLIPTIC EQUATIONS IN UNBOUNDED DOMAINS IN R^2 被引量:1
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作者 曹道珉 《Acta Mathematica Scientia》 SCIE CSCD 1994年第3期297-312,共16页
In this paper,we consider the existence of multiple positive solutions of the following inhomepeneous semilinear elliptic equation where λ> 0.ed and ω is a bounded smooth open set in R2,h(x)∈ L 2(Ω),h(x) 0.f(t)... In this paper,we consider the existence of multiple positive solutions of the following inhomepeneous semilinear elliptic equation where λ> 0.ed and ω is a bounded smooth open set in R2,h(x)∈ L 2(Ω),h(x) 0.f(t)∈ C1([0.+∝)) satisfies f(0) =f'(0)=0.fn(t) exists and fn(t)> 0.0<f(t) <Cexp(at) for some constants C,α> 0.0 <u <2 and t∈(0.+c),f(t)<0tf'(t) for someθ ∈(0,1). By looking for the local miaimum of the corresponding energy functional we tain the first minimum positive solution and by applying mountain pass lemma around the ndboum positive solution we prove the following result: 展开更多
关键词 has.at least two positive solutions if λ∈(0 λ).whereλ>0 is someconstant and(P)λ hasno positive solution if λ>λ
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BOUNDED TRAVELING WAVE SOLUTIONS OF VARIANT BOUSSINESQ EQUATION WITH A DISSIPATION TERM AND DISSIPATION EFFECT
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作者 张卫国 刘强 +1 位作者 李正明 李想 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期941-959,共19页
This article studies bounded traveling wave solutions of variant Boussinesq equation with a dissipation term and dissipation effect on them. Firstly, we make qualitative analysis to the bounded traveling wave solution... This article studies bounded traveling wave solutions of variant Boussinesq equation with a dissipation term and dissipation effect on them. Firstly, we make qualitative analysis to the bounded traveling wave solutions for the above equation by the theory and method of planar dynamical systems, and obtain their existent conditions, number, and general shape. Secondly, we investigate the dissipation effect on the shape evolution of bounded traveling wave solutions. We find out a critical value r^* which can characterize the scale of dissipation effect, and prove that the bounded traveling wave solutions appear as kink profile waves if |r|≥ r^*; while they appear as damped oscillatory waves if |r| 〈 r^*. We also obtain kink profile solitary wave solutions with and without dissipation effect. On the basis of the above discussion, we sensibly design the structure of the approximate damped oscillatory solutions according to the orbits evolution relation corresponding to the component u(ξ) in the global phase portraits, and then obtain the approximate solutions (u(ξ), H(ξ)). Furthermore, by using homogenization principle, we give their error estimates by establishing the integral equation which reflects the relation between exact and approximate solutions. Finally, we discuss the dissipation effect on the amplitude, frequency, and energy decay of the bounded traveling wave solutions. 展开更多
关键词 Variant Boussinesq equation with dissipation term shape analysis bounded traveling wave solution error estimate dissipation effect
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Boundedness of Solutions for Elliptic Variational Inequalities
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作者 Ye Ruifen(Department of Mathematics, Guangzhou Teachers’ College, 510400) 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第1期56-62,共7页
The boundedness is proved under more general structural conditions to solutions of elliptic variational inequalities and a priori estimates are obtained to maximum modulus of solutions for some special cases.
关键词 elliptic variational inequality generalized solution bounded solution:maximum modulus priori estimate
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Global Bounded Solutions for the Keller-Segel Chemotaxis System with Singular Sensitivity
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作者 Khalid Ahmed Abbakar Omer Khalil +3 位作者 Alhussein Mohamed Bechir Mahamat Abdoulaye Ali Abeer Alhadi 《Applied Mathematics》 2020年第10期985-990,共6页
In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="&q... In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="" />(0.1)<br /> <p> is considered in a bounded domain with smooth boundary, Ω &#8834;R<sup><i>n</i></sup> (<i>n</i> ≥ 1), where <i>d</i><sub>1</sub> > 0, <i>d</i><sub>2</sub> > 0 with parameter <i>χ</i> ∈ R. When <i>d</i><sub>1</sub> = <i>d</i><sub>2</sub> + <i>χ</i>, satisfying for all initial data 0 ≤ <i>n</i><sub>0</sub> ∈ <i>C</i><sup>0</sup><img src="Edit_4898c7a9-f047-4856-b9ad-8d42ecf262a2.bmp" alt="" /> and 0 < <i>v</i><sub>0</sub>∈ <i>W</i><sup>1,∞</sup> (Ω), we prove that the problem possesses a unique global classical solution which is uniformly bounded in Ω × (0, ∞). </p> 展开更多
关键词 Keller-Segel System CHEMOTAXIS Global bounded solution Singular Sensitivity
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