Approximate damped oscillatory solutions for compound KdV-Burgers equation and their error estimates

In this paper,we focus on studying approximate solutions of damped oscillatory solutions of the compound KdV-Burgers equation and their error estimates.We employ the theory of planar dynamical systems to study traveling wave solutions of the compound KdV-Burgers equation.We obtain some global phase portraits under different parameter conditions as well as the existence of bounded traveling wave solutions.Furthermore,we investigate the relations between the behavior of bounded traveling wave solutions and the dissipation coefficient r of the equation.We obtain two critical values of r,and find that a bounded traveling wave appears as a kink profile solitary wave if |r| is greater than or equal to some critical value,while it appears as a damped oscillatory wave if |r| is less than some critical value.By means of analysis and the undetermined coefficients method,we find that the compound KdV-Burgers equation only has three kinds of bell profile solitary wave solutions without dissipation.Based on the above discussions and according to the evolution relations of orbits in the global phase portraits,we obtain all approximate damped oscillatory solutions by using the undetermined coefficients method.Finally,using the homogenization principle,we establish the integral equations reflecting the relations between exact solutions and approximate solutions of damped oscillatory solutions.Moreover,we also give the error estimates for these approximate solutions.     

求解非线性方程重根的平方收敛迭代法

研究了具有重根的非线性方程的迭代方法,对基于动力系统的新牛顿类方法作了修改,改进方法仍保持了牛顿方法的二阶收敛性.数值实验结果验证了方法的有效性.     

带扩散项单种群模型的精确能控性

本文研究了一类单种群生态模型的精确能控性问题.利用线性化系统的Carleman估计和Kakutani不动点定理,证明了该模型稳态解的局部能控性.它反应了外部控制在种群演变过程中的影响作用.     

扩展Jury判据

本文给出了实系数多项式有一对或两对模长等于1的共轭复根,其余所有根的模长都小于1的代数判据．该判据的形式与Jury判据类似,其作用等同于Jury判据在判断一个多项式的所有根的模长是否都小于1时所起的作用．     

疯狂动力系统的一些性质

针对纤维映射为旋转的疯狂动力系统,比较系统的研究了它们的回复性、混合性、混沌性等基本的动力学性质.     

一类改进的非线性种群系统的最优控制

研究某一类改进的关于年龄结构的非线性种群系统的最优控制问题.首先利用常用的极小化序列方法证明最优控制问题的最优解存在;其次定义原系统对应的共轭系统,借助于法锥定义,得到最优解所要满足的必要条件.     

Random attractors of boussinesq equations with multiplicative noise

We study the random dynamical system （RDS） generated by the Benald flow problem with multiplicative noise and prove the existence of a compact random attractor for such RDS.     

微生物间歇发酵非线性动力系统的性质及最优控制

本文针对微生物间歇发酵制取1，3-丙二醇非线性动力系统，以产物1，3-丙二醇的生产强度最大为目标泛函，建立了最优控制模型．用不可微优化理论与方法证明了模型最优解的存在性．论述了最优性函数与一阶最优性条件的等价性．     

具最终状态观测的种群扩散系统最优生育率控制的非线性问题

讨论了一类与年龄相关的时变种群扩散系统最优生育率控制的非线性问题,证明了最优生育率控制的存在性,并给出了控制为最优的必要条件及其由偏微分方程组和变分不等式组成的最优性组.这些结果可为时变种群扩散系统最优控制问题的实际研究提供理论基础.     

一类半线性时变种群系统的最优捕获控制

讨论了年龄相关的半线性时变种群系统的最优捕获控制问题.根据微积分方程及泛函分析的知识证明了最优捕获控制的存在性,得到了捕获控制为最优的必要条件.