一类四阶半正边值问题正解的存在性

运用锥上的不动点定理,讨论四阶常微分方程边值问题y(4)(t)-λf(t,y(t),y″(t))=0 t∈(0,1) y(0)=y(1)=0 ay″(ξ1)-by’’’(ξ1)=0 cy″(ξ2)+dy’’’(ξ2)=0正解的存在性,其中:0≤ξ1<ξ2≤1,f∈C([0,1]×[0,+∞)×(-∞,0],R).     

一类三阶三点边值问题正解的存在性

研究具有非齐次三点边界条件的三阶三点边值问题u^m＋a（t）f（u（t））=0,t∈（0,1）,u（0）=u＇（0）=0,u＇（1）-αu＇（η）=λ正解的存在性,其中0〈α〈1,0〈η〈1,f：[0,＋∞）→[0,＋∞）连续,a：[0,1]→[0,＋∞）连续,λ〉0为参数.主要利用Schauder不动点定理给出了上述三阶三点边值问题存在正解的充分条件.     

微分学中值定理的证明及其在应用中应注意的问题

通过构造辅助函数简化了微分中值定理的证明,并通过构造2个例子指出应用微分中值定理时应注意的问题：（1）定理只指出了中间值的存在,并未具体给出求中间值的方法;（2）中间值既依赖于函数本身,且与端点a、b有关。它们之间的依赖关系是相当复杂的;（3）当区间端点连续变化时,相应的中间值并不一定连续变化．     

A INTERESTING SEQUENCE OF REAL NUMBER AND THEIR PROPERTIES

The yandongkai' s 2-stories "v' shape sequence of natural number is generalized to 2-stories and n-stories "v" shape sequence of real number,and some very interesting properties are given.x     

Optimality Conditions and Lagrange Duality for a Class of Vector Extremum Problems

A sufficient and necessary optimality conditions is established for vector extremum problems with set constraint by applying the alternative theorem under generalized subconvexlike maps in orderd locally-convex Hausdorff spaces. Then, several optimality conditions are obtained for differentiable vector extremum problems with set constraint by applying the sufficient and necessary optimality conditions and the properties of the twice G-differentiable functions. And finally, the vector-valued Lagrange duality is obtained for the vector extremum problems.     

A Method of Solving the Structural Fuzzy Finite Element Equilibrium Equations

Based on resolution of interval numbers and fuzzy resolution theorem,we develop a method of solving the structural fuzzy finite element equilibrium equations. A lot of calculations and analyses show,the method presented in this paper is correct and feasible.     

Existence of Periodic Solutions for Reaction-diffusion Systems with Time Delays

Periodic solutions of reaction-diffusion systems with time delays are investigated. The upper and lower control function of nonmonotone reaction term is constructed. It is showed that the function satisfies a global Lipschitz condition and quasimonotone. A sort of effective method of studying differential equation with nonmonotone reaction term is gained. It is shown that periodic solutions of this system exist when reaction-term is not monotone and the boundary value system has a pair of coupled to-upper and lower solutions.     

函数构造法在微分中值定理证题中的应用

在运用微分中值定理证题中．函数构造法是证题中最常用的方法之一．对一些教学中经常要用到的函数构造方法及思想进行归纳和探讨．     

关于微分中值定理的几何推广

通过曲线段自身的几何性质研究了微分中值定理的几何表示 ,把中值定理的几何意义推广到空间曲线段 ,并由此推理得几个常见的中值定理形式及其推广形式。