The rheological properties of high and low density polyethylene(HDPE and LDPE)melts were investigated by using capillary rheometer,and preliminary verification for the half natural converging angle equation of non-New...The rheological properties of high and low density polyethylene(HDPE and LDPE)melts were investigated by using capillary rheometer,and preliminary verification for the half natural converging angle equation of non-Newtonian fluids which was derived in a prerious work was made.The results showed that the natural convergent angles of the sample melts calculated by using the equation were in correspondence with the values reported in the literature under the relevant conditions.展开更多
The paper studies the convergence and the superconvergence of the biquadratic finite element for Poisson＇ problem on anisotropic meshes. By detailed analysis, it shows that the biquadratic finite element is anisotrop...The paper studies the convergence and the superconvergence of the biquadratic finite element for Poisson＇ problem on anisotropic meshes. By detailed analysis, it shows that the biquadratic finite element is anisotropically superconvergent at four Gauss points in the element. Key words：展开更多
This paper presents a new nonmonotone filter line search technique in association with the MBFGS method for solving unconstrained minimization.The filter method,which is traditionally used for constrained nonlinear pr...This paper presents a new nonmonotone filter line search technique in association with the MBFGS method for solving unconstrained minimization.The filter method,which is traditionally used for constrained nonlinear programming(NLP),is extended to solve unconstrained NLP by converting the latter to an equality constrained minimization.The nonmonotone idea is employed to the filter method so that the restoration phrase,a common feature of most filter methods,is not needed.The global convergence and fast local convergence rate of the proposed algorithm are established under some reasonable conditions.The results of numerical experiments indicate that the proposed method is efficient.展开更多
文摘The rheological properties of high and low density polyethylene(HDPE and LDPE)melts were investigated by using capillary rheometer,and preliminary verification for the half natural converging angle equation of non-Newtonian fluids which was derived in a prerious work was made.The results showed that the natural convergent angles of the sample melts calculated by using the equation were in correspondence with the values reported in the literature under the relevant conditions.
基金the Henan Natural Science Foundation(072300410320)the Foundation Study of the Education Department of Henan Province(200510460311)
文摘The paper studies the convergence and the superconvergence of the biquadratic finite element for Poisson＇ problem on anisotropic meshes. By detailed analysis, it shows that the biquadratic finite element is anisotropically superconvergent at four Gauss points in the element. Key words：
基金supported by the National Science Foundation under Grant No.11371253the Science Foundation under Grant No.11C0336 of Provincial Education Department of Hunan
文摘This paper presents a new nonmonotone filter line search technique in association with the MBFGS method for solving unconstrained minimization.The filter method,which is traditionally used for constrained nonlinear programming(NLP),is extended to solve unconstrained NLP by converting the latter to an equality constrained minimization.The nonmonotone idea is employed to the filter method so that the restoration phrase,a common feature of most filter methods,is not needed.The global convergence and fast local convergence rate of the proposed algorithm are established under some reasonable conditions.The results of numerical experiments indicate that the proposed method is efficient.
