The global asymptotic behavior of solutions for the equations of large-scale atmospheric motion with the non-stationary external forcing is studied in the infinite-dimensional Hilbert space. Based on the properties of...The global asymptotic behavior of solutions for the equations of large-scale atmospheric motion with the non-stationary external forcing is studied in the infinite-dimensional Hilbert space. Based on the properties of operators of the equations, some energy inequalities and the uniqueness theorem of solutions are obtained. On the assumption that external forces are bounded, the exsitence of the global absorbing set and the atmosphere attractor is proved, and the characteristics of the decay of effect of initial field and the adjustment to the external forcing are revealed. The physical sense of the results is discussed and some ideas about climatic numerical forecast are elucidated.展开更多
Many questions in natural science and engineering can be transformed into nonlinear equations. Newton iteration method is an important technique to one dimensional and multidimensional variables and iteration itself i...Many questions in natural science and engineering can be transformed into nonlinear equations. Newton iteration method is an important technique to one dimensional and multidimensional variables and iteration itself is very sensitive to initial guess point. This sensitive area is the Julia set of nonlinear discrete dynamic system which Newton iteration method forms. The Julia set, which is the boundaries of basins of attractions, displays the intricate fractal structures and chaos phenomena. By constructing repulsion two-cycle point function and making use of inverse image iteration method, a method to find Julia set point was introduced. For the first time, a new method to find all solutions was proposed based on utilizing sensitive fractal areas to locate the Julia set points to find all solutions of the nonlinear questions. The developed technique used an important feature of fractals to preserve shape of basins of attraction on infinitely small scales. The numerical examples in linkage synthesis showed that the method was effective and correct.展开更多
In this paper,we consider solving the topology optimization for steady-state incompressibleNavier-Stokes problems via a new topology optimization method called parameterized level set method,which can maintain a relat...In this paper,we consider solving the topology optimization for steady-state incompressibleNavier-Stokes problems via a new topology optimization method called parameterized level set method,which can maintain a relatively smooth level set function with a local optimality condition.The objective of topology optimization is tond an optimal conguration of theuid and solid materials that minimizes power dissipation under a prescribeduid volume fraction constraint.An articial friction force is added to the Navier-Stokes equations to apply the no-slip boundary condition.Although a great deal of work has been carried out for topology optimization ofuidow in recent years,there are few researches on the topology optimization ofuidow with physical body forces.To simulate theuidow in reality,the constant body force(e.g.,gravity)is considered in this paper.Several 2D numerical examples are presented to discuss the relationships between the proposed method with Reynolds number and initial design,and demonstrate the feasibility and superiority of the proposed method in dealing with unstructuredmesh problems.Three 3D numerical examples demonstrate the proposedmethod is feasible in three-dimensional.展开更多
A method for solving nonlinear polynomial equations is given which avoids theappearance of redundant factors as in the previous characteristic set method developed bythe present author. The new method seems thus to be...A method for solving nonlinear polynomial equations is given which avoids theappearance of redundant factors as in the previous characteristic set method developed bythe present author. The new method seems thus to be of much higher efficiency than theprevious one. It has the further advantage that numerical data may be inserted at willeither at the outset or during the procedure so far removal of factors by divisions may beavoided.展开更多
In this paper we improve the character approach to the multiplier conjecture that we presented after 1992, and thus we have made considerable progress in the case of n = 3n1. We prove that in the case of n = 3n1 Secon...In this paper we improve the character approach to the multiplier conjecture that we presented after 1992, and thus we have made considerable progress in the case of n = 3n1. We prove that in the case of n = 3n1 Second multiplier theorem remains true if the assumption “n1 > λ” is replaced by “(n1, λ) = 1”. Consequentially we prove that if we let D be a (v, k, λ)-difference set in an abelian group G, and n = 3pr for some prime p, (p,v) = 1, then p is a numerical multiplier of D.展开更多
This article is devoted to obtaining sufficient conditions for the completion of pursuit for control systems of fractional order described with divided dynamics. The results are illustrated on model examples of gaming...This article is devoted to obtaining sufficient conditions for the completion of pursuit for control systems of fractional order described with divided dynamics. The results are illustrated on model examples of gaming problems with a simple matrix and separated fractional-order motions.展开更多
For entire or meromorphic function f,a value θ∈[0,2π)is called a Julia limiting direction if there is an unbounded sequence{z_(n)}in the Julia set satisfying limn→∞ arg z_(n)=θ.Our main result is on the entire s...For entire or meromorphic function f,a value θ∈[0,2π)is called a Julia limiting direction if there is an unbounded sequence{z_(n)}in the Julia set satisfying limn→∞ arg z_(n)=θ.Our main result is on the entire solution f of P(z,f)+F(z)f^(s)=0,where P(z,f)is a differential polynomial of f with entire coefficients of growth smaller than that of the entire transcendental F,with the integer s being no more than the minimum degree of all differential monomials in P(z,f). We observe that Julia limiting directions of f partly come from the directions in which F grows quickly.展开更多
In this paper, we introduce a new invariant set Eo={u：ux=f＇（x）F（u）＋ε[g＇（x）-f＇（x）g（x）]F（u）×exp（-∫^u1/F（z）dz）}where f and g are some smooth functions of x, ε is a constant, and F is a smooth...In this paper, we introduce a new invariant set Eo={u：ux=f＇（x）F（u）＋ε[g＇（x）-f＇（x）g（x）]F（u）×exp（-∫^u1/F（z）dz）}where f and g are some smooth functions of x, ε is a constant, and F is a smooth function to be determined. The invariant sets and exact sohltions to nonlinear diffusion equation ut = （ D（u）ux）x ＋ Q（x, u）ux ＋ P（x, u）, are discussed. It is shown that there exist several classes of solutions to the equation that belong to the invariant set Eo.展开更多
基金Work supported by the State Key Reseach Project on Dynamics and Predictive Theory of the Climate
文摘The global asymptotic behavior of solutions for the equations of large-scale atmospheric motion with the non-stationary external forcing is studied in the infinite-dimensional Hilbert space. Based on the properties of operators of the equations, some energy inequalities and the uniqueness theorem of solutions are obtained. On the assumption that external forces are bounded, the exsitence of the global absorbing set and the atmosphere attractor is proved, and the characteristics of the decay of effect of initial field and the adjustment to the external forcing are revealed. The physical sense of the results is discussed and some ideas about climatic numerical forecast are elucidated.
基金Sponsored by the Scientific Research Fund of Ministry Education(Grant No.02108),and the Key Scientific Research Fund of Hunan Provincial Education Depart-ment(Grant No.04A036),and the Grant of the11-th Five-year Plan for Key Construction Disciplines Mechanical Design and Theory of Hunan Province.
文摘Many questions in natural science and engineering can be transformed into nonlinear equations. Newton iteration method is an important technique to one dimensional and multidimensional variables and iteration itself is very sensitive to initial guess point. This sensitive area is the Julia set of nonlinear discrete dynamic system which Newton iteration method forms. The Julia set, which is the boundaries of basins of attractions, displays the intricate fractal structures and chaos phenomena. By constructing repulsion two-cycle point function and making use of inverse image iteration method, a method to find Julia set point was introduced. For the first time, a new method to find all solutions was proposed based on utilizing sensitive fractal areas to locate the Julia set points to find all solutions of the nonlinear questions. The developed technique used an important feature of fractals to preserve shape of basins of attraction on infinitely small scales. The numerical examples in linkage synthesis showed that the method was effective and correct.
基金supported by the National Natural Science Foundation of China (Grant No.12072114)the National Key Research and Development Plan (Grant No.2020YFB1709401)the Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology (2021B1212040003).
文摘In this paper,we consider solving the topology optimization for steady-state incompressibleNavier-Stokes problems via a new topology optimization method called parameterized level set method,which can maintain a relatively smooth level set function with a local optimality condition.The objective of topology optimization is tond an optimal conguration of theuid and solid materials that minimizes power dissipation under a prescribeduid volume fraction constraint.An articial friction force is added to the Navier-Stokes equations to apply the no-slip boundary condition.Although a great deal of work has been carried out for topology optimization ofuidow in recent years,there are few researches on the topology optimization ofuidow with physical body forces.To simulate theuidow in reality,the constant body force(e.g.,gravity)is considered in this paper.Several 2D numerical examples are presented to discuss the relationships between the proposed method with Reynolds number and initial design,and demonstrate the feasibility and superiority of the proposed method in dealing with unstructuredmesh problems.Three 3D numerical examples demonstrate the proposedmethod is feasible in three-dimensional.
基金The present project is partially supported by NSFC Grant JI85312.
文摘A method for solving nonlinear polynomial equations is given which avoids theappearance of redundant factors as in the previous characteristic set method developed bythe present author. The new method seems thus to be of much higher efficiency than theprevious one. It has the further advantage that numerical data may be inserted at willeither at the outset or during the procedure so far removal of factors by divisions may beavoided.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 19831070).
文摘In this paper we improve the character approach to the multiplier conjecture that we presented after 1992, and thus we have made considerable progress in the case of n = 3n1. We prove that in the case of n = 3n1 Second multiplier theorem remains true if the assumption “n1 > λ” is replaced by “(n1, λ) = 1”. Consequentially we prove that if we let D be a (v, k, λ)-difference set in an abelian group G, and n = 3pr for some prime p, (p,v) = 1, then p is a numerical multiplier of D.
文摘This article is devoted to obtaining sufficient conditions for the completion of pursuit for control systems of fractional order described with divided dynamics. The results are illustrated on model examples of gaming problems with a simple matrix and separated fractional-order motions.
基金This work was supported by the National Natural Science Foundation of China(11771090,11901311)Natural Sciences Foundation of Shanghai(17ZR1402900).
文摘For entire or meromorphic function f,a value θ∈[0,2π)is called a Julia limiting direction if there is an unbounded sequence{z_(n)}in the Julia set satisfying limn→∞ arg z_(n)=θ.Our main result is on the entire solution f of P(z,f)+F(z)f^(s)=0,where P(z,f)is a differential polynomial of f with entire coefficients of growth smaller than that of the entire transcendental F,with the integer s being no more than the minimum degree of all differential monomials in P(z,f). We observe that Julia limiting directions of f partly come from the directions in which F grows quickly.
基金National Natural Science Foundation of China under Grant Nos.10472091,10332030,and 10502042the Natural Science Foundation of Shaanxi Province under Grant No.2003A03
文摘In this paper, we introduce a new invariant set Eo={u：ux=f＇（x）F（u）＋ε[g＇（x）-f＇（x）g（x）]F（u）×exp（-∫^u1/F（z）dz）}where f and g are some smooth functions of x, ε is a constant, and F is a smooth function to be determined. The invariant sets and exact sohltions to nonlinear diffusion equation ut = （ D（u）ux）x ＋ Q（x, u）ux ＋ P（x, u）, are discussed. It is shown that there exist several classes of solutions to the equation that belong to the invariant set Eo.
