In this paper,we consider the 3D magnetic Bénard problem.More precisely,we prove that the large solutions are stable under certain conditions.And we obtain the equivalent condition with respect to this stability ...In this paper,we consider the 3D magnetic Bénard problem.More precisely,we prove that the large solutions are stable under certain conditions.And we obtain the equivalent condition with respect to this stability condition.Finally,we also establish the stability of 2 D magnetic Bénard problem under 3D perturbations.展开更多
The special structure in some coupled equations makes it possible to drop partial smallness assumption of the initial data to gain the global well-posedness.In this paper,we study the Cauchy problem for generalized De...The special structure in some coupled equations makes it possible to drop partial smallness assumption of the initial data to gain the global well-posedness.In this paper,we study the Cauchy problem for generalized Debye-Hückel system in Fourier-Besov spaces.Under more generalized index range,we obtain the global solution with small initial data and local solution with arbitrary initial.Besides,by constructing some weighted function,we prove that the global well-posedness still holds under the small assumption of the charge of initial data.Thus we show that although the initial densities and the hole in electrolytes are large,the equation is still global well-posedness.展开更多
We consider the global well-posedness of strong solutions to the Cauchy problem of compressible barotropic Navier-Stokes equations in R^(2). By exploiting the global-in-time estimate to the two-dimensional(2D for shor...We consider the global well-posedness of strong solutions to the Cauchy problem of compressible barotropic Navier-Stokes equations in R^(2). By exploiting the global-in-time estimate to the two-dimensional(2D for short) classical incompressible Navier-Stokes equations and using techniques developed in(SIAM J Math Anal, 2020, 52(2): 1806–1843), we derive the global existence of solutions provided that the initial data satisfies some smallness condition. In particular, the initial velocity with some arbitrary Besov norm of potential part Pu_0 and large high oscillation are allowed in our results. Moreover, we also construct an example with the initial data involving such a smallness condition, but with a norm that is arbitrarily large.展开更多
We study positive solutions to the fractional semi-linear elliptic equation(−∆)σu=K(x)u n+2σn−2σin B2\{0}with an isolated singularity at the origin,where K is a positive function on B2,the punctured ball B2\{0}⊂Rn ...We study positive solutions to the fractional semi-linear elliptic equation(−∆)σu=K(x)u n+2σn−2σin B2\{0}with an isolated singularity at the origin,where K is a positive function on B2,the punctured ball B2\{0}⊂Rn with n>2,σ∈(0,1),and(−∆)σis the fractional Laplacian.In lower dimensions,we show that for any K∈C1(B2),a positive solution u always satisfies that u(x)6 C|x|−(n−2σ)/2 near the origin.In contrast,we construct positive functions K∈C1(B2)in higher dimensions such that a positive solution u could be arbitrarily large near the origin.In particular,these results also apply to the prescribed boundary mean curvature equations on B n+1.展开更多
In this paper, we derive the global existence of smooth solutions of the 3D incompressible Euler equations with damping for a class of large initial data, whose Sobolev norms H8 can be arbitrarily large for any s ≥0...In this paper, we derive the global existence of smooth solutions of the 3D incompressible Euler equations with damping for a class of large initial data, whose Sobolev norms H8 can be arbitrarily large for any s ≥0. The approach is through studying the quantity representing the difference between the vortieity and velocity. And also, we construct a family of large solutions for MHD equations with damping.展开更多
This paper is concerned with the boundary behavior of strictly convex large solutions to the Monge–Ampère equation det D^2u(x) = b(x)f(u(x)), u >0, x∈Ω, where Ω is a strictly convex and bounded smooth doma...This paper is concerned with the boundary behavior of strictly convex large solutions to the Monge–Ampère equation det D^2u(x) = b(x)f(u(x)), u >0, x∈Ω, where Ω is a strictly convex and bounded smooth domain in R^N with N ≥ 2, f is normalized regularly varying at infinity with the critical index N and has a lower term, and b∈C~∞(Ω) is positive in Ω, but may be appropriate singular on the boundary.展开更多
This paper is concerned with exact boundary behavior of large solutions to semilinear elliptic equations △u=b(x)f(u)(C0+|▽u|q),x∈Ω,where Ω is a bounded domain with a smooth boundary in RN,C0≥0,q E [0,2),b∈Cloc...This paper is concerned with exact boundary behavior of large solutions to semilinear elliptic equations △u=b(x)f(u)(C0+|▽u|q),x∈Ω,where Ω is a bounded domain with a smooth boundary in RN,C0≥0,q E [0,2),b∈Clocα(Ω) is positive in but may be vanishing or appropriately singular on the boundary,f∈C[0,∞),f(0)=0,and f is strictly increasing on [0,∞)(or f∈C(R),f(s)> 0,■s∈R,f is strictly increasing on R).We show unified boundary behavior of such solutions to the problem under a new structure condition on f.展开更多
By using Karamata regular variation theory and upper and lower solution method,we investigate the existence and the global asymptotic behavior of large solutions to a class of semilinear elliptic equations with nonlin...By using Karamata regular variation theory and upper and lower solution method,we investigate the existence and the global asymptotic behavior of large solutions to a class of semilinear elliptic equations with nonlinear convection terms.In our study,the weight and nonlinearity are controlled by some regularly varying functions or rapid functions,which is very different from the conditions of previous contexts.Our results largely extend the previous works,and prove that the nonlinear convection terms do not affect the global asymptotic behavior of classical solutions when the index of the convection terms change in a certain range.展开更多
This paper is concerned with strictly k-convex large solutions to Hessian equations Sk(D2u(x))=b(x)f(u(x)),x∈Ω,whereΩis a strictly(k-1)-convex and bounded smooth domain in Rn,b∈C∞(Ω)is positive inΩ,but may be v...This paper is concerned with strictly k-convex large solutions to Hessian equations Sk(D2u(x))=b(x)f(u(x)),x∈Ω,whereΩis a strictly(k-1)-convex and bounded smooth domain in Rn,b∈C∞(Ω)is positive inΩ,but may be vanishing on the boundary.Under a new structure condition on f at infinity,the author studies the refined boundary behavior of such solutions.The results are obtained in a more general setting than those in[Huang,Y.,Boundary asymptotical behavior of large solutions to Hessian equations,Pacific J.Math.,244,2010,85–98],where f is regularly varying at infinity with index p>k.展开更多
In this note, we consider positive entire large solutions for semilinear elliptic equations Au = p(x)f(u) in R^N with N ≥ 3. More precisely, we are interested in the link between the existence of entire large sol...In this note, we consider positive entire large solutions for semilinear elliptic equations Au = p(x)f(u) in R^N with N ≥ 3. More precisely, we are interested in the link between the existence of entire large solution with the behavior of solution for --△u = p(x) in R^N. Especially for the radial case, we try to give a survey of all possible situations under Keller-Osserman type conditions.展开更多
We consider the problem of whether the equation △u = p(x)f(u) on RN, N ≥ 3, has a positive solution for which lim |x|→∞(x) = ∞ where f is locally Lipschitz continuous, positive, and nondecreasing on (0,o...We consider the problem of whether the equation △u = p(x)f(u) on RN, N ≥ 3, has a positive solution for which lim |x|→∞(x) = ∞ where f is locally Lipschitz continuous, positive, and nondecreasing on (0,oo) and satisfies ∫1∞[F (t)]^- 1/2dt = ∞ where F(t) = ∫0^tf(s)ds. The nonnegative function p is assumed to be asymptotically radial in a certain sense. We show that a sufficient condition to ensure such a solution u exists is that p satisfies ∫0∞ r min|x|=r P (x) dr = ∞. Conversely, we show that a necessary condition for the solution to exist is that p satisfies ∫0∞r1+ε min |x|=rp(x)dr =∞ for all ε〉0.展开更多
We establish the existence, uniqueness and the blow-up rate of the large positive solution of the quasi-linear elliptic problem -△pu=λ(x)u^θ-1-b(x)h(u), in Ω,with boundary condition u = +∞ on δΩ, where ...We establish the existence, uniqueness and the blow-up rate of the large positive solution of the quasi-linear elliptic problem -△pu=λ(x)u^θ-1-b(x)h(u), in Ω,with boundary condition u = +∞ on δΩ, where Ω R^N (N≥2) is a smooth bounded domain, 1 〈 p 〈∞ λ(·) and b(·) are positive weight functions and h(u) ~ uq-1 as u → ∞. Our results extend the previous work [Z. Xie, J. Diff. Equ., 247 (2009), 344-363] from case p = 2, λ is a constant and θ = 2 to case 1 〈 p 〈∞, A is a function and 1 ( 0 〈 θ 〈q 〉 p); and also extends the previous work [Z. Xie, C. Zhao, J. Diff. Equ., 252 (2012), 1776-1788], from case A is a constant and θ = p to case λ is a function and 1 〈 θ 〈 q ( 〉 p). Moreover, we remove the assumption of radial symmetry of the problem and we do not require h(·) is increasing.展开更多
The existence ofpositive radialsolutions ofthe equation - div(|Du|p- 2Du)= f(u) is studied in annular dom ains in Rn,n≥2. Itisproved thatiff(0)≥0, f is somewhere negativein (0,∞), lim u→0+ f′(u)= 0and lim u→...The existence ofpositive radialsolutions ofthe equation - div(|Du|p- 2Du)= f(u) is studied in annular dom ains in Rn,n≥2. Itisproved thatiff(0)≥0, f is somewhere negativein (0,∞), lim u→0+ f′(u)= 0and lim u→∞(f(u)/up- 1)= ∞, then thereisa largepositiveradialsolution on allannuli.Iff(0)< 0 and satisfiescertain condi- tions, then the equation has no radialsolution ifthe annuliare too wide.展开更多
In this paper the semi-analytical analyses of the flexible cantilever tapered functionally graded beam under combined inclined end loading and intermediate loading are studied.In order to derive the fully non-linear e...In this paper the semi-analytical analyses of the flexible cantilever tapered functionally graded beam under combined inclined end loading and intermediate loading are studied.In order to derive the fully non-linear equations governing the non-linear deformation,a curvilinear coordinate system is introduced.A general non-linear second order differential equation that governs the shape of a deflected beam is derived based on the geometric nonlinearities,infinitesimal local displacements and local rotation concepts with remarkable physical properties of functionally graded materials.The solutions obtained from semi-analytical methods are numerically compared with the existing elliptic integral solution for the case of a flexible uniform cantilever functionally graded beam.The effects of taper ratio,inclined end load angle and material property gradient on large deflection of the beam are evaluated.The Adomian decomposition method will be useful toward the design of tapered functionally graded compliant mechanisms driven by smart actuators.展开更多
In this paper, Von Karman's set of nonlinear equations for rectangular plates with large deflection is divided into several sets of linear equations by perturbation method, the dimensionless center deflection bein...In this paper, Von Karman's set of nonlinear equations for rectangular plates with large deflection is divided into several sets of linear equations by perturbation method, the dimensionless center deflection being taken as a perturbation parameter. These sets of linear equations are solved by the spline finite-point (SFP) method and by the spline finite element (SFE) method. The solutions for rectangular plates having any length-to-width ratios under a uniformly distributed load and with various boundary conditions are presented, and the analytical formulas for displacements and deflections are given in the paper. The computer programs are worked out by ourselves. Comparison of the results with those in other papers indicates that the results of this paper are satisfactorily better.展开更多
ZTE Corporation announced that it has completed the Inter-Operability Test (IOT)of its 3GPP R7-basedHSPA+ MIMO solution,conducted in conjunction with mainstream terminal chip platform vendors,in July 2009.
In this paper, we study the existence of positive entire large and bounded radial positive solutions for the following nonlinear system {Sk1(λ(D2u1))+a1(|x|)|△u1|k1=p1(|x|)f1(u2) for x∈RN,Sk2(λ...In this paper, we study the existence of positive entire large and bounded radial positive solutions for the following nonlinear system {Sk1(λ(D2u1))+a1(|x|)|△u1|k1=p1(|x|)f1(u2) for x∈RN,Sk2(λ(D2u2))+a2(|x|)|△u2|k2=p2(|x|)f2(u1) for x∈RN.Here Ski (λ (D2ui)) is the ki-Hessian operator, a1, p1, f1, a2, p2 and f2 are continuous functions.展开更多
In this paper,we consider the periodic solution problems for the systems with unbounded delay,and the existence,uniqueness and stability of the periodic solution are dealt with unitedly.First we establish the suitable...In this paper,we consider the periodic solution problems for the systems with unbounded delay,and the existence,uniqueness and stability of the periodic solution are dealt with unitedly.First we establish the suitable delay-differential inequality,then study seperately the problems of periodic solution for the systems with bounded delay,with unbounded delay and the Volterra integral-dlfferentlal systems with infinite delay by using the character of matrix measure and the asymptotic fixed point theorem of poincaré’s periodic operator in the different phase spaces.A series of simple criteria for the existence,uniqueness and stability of these systems are obtained.展开更多
In this paper,we investigate the initial value problem for the two-dimensiona magneto-micropolar fluid equations with partial viscosity.We prove that global existence of smooth large solutions by the energy method.Fur...In this paper,we investigate the initial value problem for the two-dimensiona magneto-micropolar fluid equations with partial viscosity.We prove that global existence of smooth large solutions by the energy method.Furthermore,with aid of the Fourier splitting methods,optimal time-decay rates of global smooth large solutions are also established.展开更多
基金supported partially by NSFC(11571380,11971497,11871230)Natural Science Foundation of GuangDong Province(2019B151502041)+3 种基金supported partially by NSFC(11126266)Natural Science Foundation of GuangDong Province(2016A030313390)SCAU Fund for High-level University Buildingsupported partially by NSFC(11971496)。
文摘In this paper,we consider the 3D magnetic Bénard problem.More precisely,we prove that the large solutions are stable under certain conditions.And we obtain the equivalent condition with respect to this stability condition.Finally,we also establish the stability of 2 D magnetic Bénard problem under 3D perturbations.
基金Supported by Natural Science Foundation of Jiangsu Province(No.BK20200587)。
文摘The special structure in some coupled equations makes it possible to drop partial smallness assumption of the initial data to gain the global well-posedness.In this paper,we study the Cauchy problem for generalized Debye-Hückel system in Fourier-Besov spaces.Under more generalized index range,we obtain the global solution with small initial data and local solution with arbitrary initial.Besides,by constructing some weighted function,we prove that the global well-posedness still holds under the small assumption of the charge of initial data.Thus we show that although the initial densities and the hole in electrolytes are large,the equation is still global well-posedness.
基金Zhai was partially supported by the Guangdong Provincial Natural Science Foundation (2022A1515011977)the Science and Technology Program of Shenzhen(20200806104726001)+1 种基金Zhong was partially supported by the NNSF of China (11901474, 12071359)the Exceptional Young Talents Project of Chongqing Talent (cstc2021ycjh-bgzxm0153)。
文摘We consider the global well-posedness of strong solutions to the Cauchy problem of compressible barotropic Navier-Stokes equations in R^(2). By exploiting the global-in-time estimate to the two-dimensional(2D for short) classical incompressible Navier-Stokes equations and using techniques developed in(SIAM J Math Anal, 2020, 52(2): 1806–1843), we derive the global existence of solutions provided that the initial data satisfies some smallness condition. In particular, the initial velocity with some arbitrary Besov norm of potential part Pu_0 and large high oscillation are allowed in our results. Moreover, we also construct an example with the initial data involving such a smallness condition, but with a norm that is arbitrarily large.
文摘We study positive solutions to the fractional semi-linear elliptic equation(−∆)σu=K(x)u n+2σn−2σin B2\{0}with an isolated singularity at the origin,where K is a positive function on B2,the punctured ball B2\{0}⊂Rn with n>2,σ∈(0,1),and(−∆)σis the fractional Laplacian.In lower dimensions,we show that for any K∈C1(B2),a positive solution u always satisfies that u(x)6 C|x|−(n−2σ)/2 near the origin.In contrast,we construct positive functions K∈C1(B2)in higher dimensions such that a positive solution u could be arbitrarily large near the origin.In particular,these results also apply to the prescribed boundary mean curvature equations on B n+1.
基金Supported by Key Laboratory of Mathematics for Nonlinear Sciences(Fudan University)Ministry of Education of China,P.R.China,Shanghai Key Laboratory for Contemporary Applied Mathematics+2 种基金School of Mathematical Sciences,Fudan University,P.R.China,NSFC(Grant No.11421061)973 Program(Grant No.2013CB834100)111 project
文摘In this paper, we derive the global existence of smooth solutions of the 3D incompressible Euler equations with damping for a class of large initial data, whose Sobolev norms H8 can be arbitrarily large for any s ≥0. The approach is through studying the quantity representing the difference between the vortieity and velocity. And also, we construct a family of large solutions for MHD equations with damping.
基金supported by NSF of P.R.China(Grant No.11571295)
文摘This paper is concerned with the boundary behavior of strictly convex large solutions to the Monge–Ampère equation det D^2u(x) = b(x)f(u(x)), u >0, x∈Ω, where Ω is a strictly convex and bounded smooth domain in R^N with N ≥ 2, f is normalized regularly varying at infinity with the critical index N and has a lower term, and b∈C~∞(Ω) is positive in Ω, but may be appropriate singular on the boundary.
基金supported by National Natural Science Foundation of China (Grant No. 11571295)
文摘This paper is concerned with exact boundary behavior of large solutions to semilinear elliptic equations △u=b(x)f(u)(C0+|▽u|q),x∈Ω,where Ω is a bounded domain with a smooth boundary in RN,C0≥0,q E [0,2),b∈Clocα(Ω) is positive in but may be vanishing or appropriately singular on the boundary,f∈C[0,∞),f(0)=0,and f is strictly increasing on [0,∞)(or f∈C(R),f(s)> 0,■s∈R,f is strictly increasing on R).We show unified boundary behavior of such solutions to the problem under a new structure condition on f.
基金Supported by Startup Foundation for Docotors of Weifang University(2016BS04)
文摘By using Karamata regular variation theory and upper and lower solution method,we investigate the existence and the global asymptotic behavior of large solutions to a class of semilinear elliptic equations with nonlinear convection terms.In our study,the weight and nonlinearity are controlled by some regularly varying functions or rapid functions,which is very different from the conditions of previous contexts.Our results largely extend the previous works,and prove that the nonlinear convection terms do not affect the global asymptotic behavior of classical solutions when the index of the convection terms change in a certain range.
基金the National Natural Science Foundation of China(No.11571295)RP of Shandong Higher Education Institutions(No.J17KA173)。
文摘This paper is concerned with strictly k-convex large solutions to Hessian equations Sk(D2u(x))=b(x)f(u(x)),x∈Ω,whereΩis a strictly(k-1)-convex and bounded smooth domain in Rn,b∈C∞(Ω)is positive inΩ,but may be vanishing on the boundary.Under a new structure condition on f at infinity,the author studies the refined boundary behavior of such solutions.The results are obtained in a more general setting than those in[Huang,Y.,Boundary asymptotical behavior of large solutions to Hessian equations,Pacific J.Math.,244,2010,85–98],where f is regularly varying at infinity with index p>k.
文摘In this note, we consider positive entire large solutions for semilinear elliptic equations Au = p(x)f(u) in R^N with N ≥ 3. More precisely, we are interested in the link between the existence of entire large solution with the behavior of solution for --△u = p(x) in R^N. Especially for the radial case, we try to give a survey of all possible situations under Keller-Osserman type conditions.
文摘We consider the problem of whether the equation △u = p(x)f(u) on RN, N ≥ 3, has a positive solution for which lim |x|→∞(x) = ∞ where f is locally Lipschitz continuous, positive, and nondecreasing on (0,oo) and satisfies ∫1∞[F (t)]^- 1/2dt = ∞ where F(t) = ∫0^tf(s)ds. The nonnegative function p is assumed to be asymptotically radial in a certain sense. We show that a sufficient condition to ensure such a solution u exists is that p satisfies ∫0∞ r min|x|=r P (x) dr = ∞. Conversely, we show that a necessary condition for the solution to exist is that p satisfies ∫0∞r1+ε min |x|=rp(x)dr =∞ for all ε〉0.
基金Acknowledgments Research is partly supported by the National Science Foundation of China (10701066 & 10971087).
文摘We establish the existence, uniqueness and the blow-up rate of the large positive solution of the quasi-linear elliptic problem -△pu=λ(x)u^θ-1-b(x)h(u), in Ω,with boundary condition u = +∞ on δΩ, where Ω R^N (N≥2) is a smooth bounded domain, 1 〈 p 〈∞ λ(·) and b(·) are positive weight functions and h(u) ~ uq-1 as u → ∞. Our results extend the previous work [Z. Xie, J. Diff. Equ., 247 (2009), 344-363] from case p = 2, λ is a constant and θ = 2 to case 1 〈 p 〈∞, A is a function and 1 ( 0 〈 θ 〈q 〉 p); and also extends the previous work [Z. Xie, C. Zhao, J. Diff. Equ., 252 (2012), 1776-1788], from case A is a constant and θ = p to case λ is a function and 1 〈 θ 〈 q ( 〉 p). Moreover, we remove the assumption of radial symmetry of the problem and we do not require h(·) is increasing.
文摘The existence ofpositive radialsolutions ofthe equation - div(|Du|p- 2Du)= f(u) is studied in annular dom ains in Rn,n≥2. Itisproved thatiff(0)≥0, f is somewhere negativein (0,∞), lim u→0+ f′(u)= 0and lim u→∞(f(u)/up- 1)= ∞, then thereisa largepositiveradialsolution on allannuli.Iff(0)< 0 and satisfiescertain condi- tions, then the equation has no radialsolution ifthe annuliare too wide.
文摘In this paper the semi-analytical analyses of the flexible cantilever tapered functionally graded beam under combined inclined end loading and intermediate loading are studied.In order to derive the fully non-linear equations governing the non-linear deformation,a curvilinear coordinate system is introduced.A general non-linear second order differential equation that governs the shape of a deflected beam is derived based on the geometric nonlinearities,infinitesimal local displacements and local rotation concepts with remarkable physical properties of functionally graded materials.The solutions obtained from semi-analytical methods are numerically compared with the existing elliptic integral solution for the case of a flexible uniform cantilever functionally graded beam.The effects of taper ratio,inclined end load angle and material property gradient on large deflection of the beam are evaluated.The Adomian decomposition method will be useful toward the design of tapered functionally graded compliant mechanisms driven by smart actuators.
文摘In this paper, Von Karman's set of nonlinear equations for rectangular plates with large deflection is divided into several sets of linear equations by perturbation method, the dimensionless center deflection being taken as a perturbation parameter. These sets of linear equations are solved by the spline finite-point (SFP) method and by the spline finite element (SFE) method. The solutions for rectangular plates having any length-to-width ratios under a uniformly distributed load and with various boundary conditions are presented, and the analytical formulas for displacements and deflections are given in the paper. The computer programs are worked out by ourselves. Comparison of the results with those in other papers indicates that the results of this paper are satisfactorily better.
文摘ZTE Corporation announced that it has completed the Inter-Operability Test (IOT)of its 3GPP R7-basedHSPA+ MIMO solution,conducted in conjunction with mainstream terminal chip platform vendors,in July 2009.
文摘In this paper, we study the existence of positive entire large and bounded radial positive solutions for the following nonlinear system {Sk1(λ(D2u1))+a1(|x|)|△u1|k1=p1(|x|)f1(u2) for x∈RN,Sk2(λ(D2u2))+a2(|x|)|△u2|k2=p2(|x|)f2(u1) for x∈RN.Here Ski (λ (D2ui)) is the ki-Hessian operator, a1, p1, f1, a2, p2 and f2 are continuous functions.
文摘In this paper,we consider the periodic solution problems for the systems with unbounded delay,and the existence,uniqueness and stability of the periodic solution are dealt with unitedly.First we establish the suitable delay-differential inequality,then study seperately the problems of periodic solution for the systems with bounded delay,with unbounded delay and the Volterra integral-dlfferentlal systems with infinite delay by using the character of matrix measure and the asymptotic fixed point theorem of poincaré’s periodic operator in the different phase spaces.A series of simple criteria for the existence,uniqueness and stability of these systems are obtained.
基金supported in part by the NNSF of China(Grant No.11871212)the Basic Research Project of Key Scientific Research Project Plan of Universities in Henan Province(Grant No.20ZX002).
文摘In this paper,we investigate the initial value problem for the two-dimensiona magneto-micropolar fluid equations with partial viscosity.We prove that global existence of smooth large solutions by the energy method.Furthermore,with aid of the Fourier splitting methods,optimal time-decay rates of global smooth large solutions are also established.