非线性微分方程正解的不存在性

本文研究了非线性微分方程正解不存在性     

一类非线性分数微分方程正解的存在唯一性

通过构造上、下控制函数,结合上、下解方法及不动点理论,研究了一类非线性项不具任何单调性的分数微分方程,获得了其正解存在性及唯一性的充分条件,推广了已有的一些结果.     

一类非线性常微分方程边值问题正解的存在唯一性

一类非线性常微分方程边值问题正解的存在唯一性赵增勤（曲阜师范大学数学系，曲阜２７３１６５）文献［１］对非线性两点边值问题解的存在性与唯一性的研究情况及其方法进行了系统而全面的总结。另外关于这方面的研究可参见［２－５］．但在实际应用中有时正解是重要的。...     

一类非线性方程正解的存在唯一性

本文证明了形如Ａ＝Ｂ＋Ｃ的算子，其中Ｂ为线性算子，Ｃ为ψ－凹算子不动点的存在唯一及迭代收敛性，并将所获结果就用于常微分方程，偏微分方程和各人分方程得到了新的结论。     

一类非线性差分方程正解的不存在性

本文研究一类非线性差分方程及其对偶方程,给出了方程不存在正解的充分条件,所得结论改进了[1]的结果。     

一类非线性微分方程的存在唯一性

在有界区域上研究了一类非线性微分方程解的存在唯一性。     

一类退化椭圆方程组正解的存在性和唯一性

In this paper we study a class of degenerate nonlinear elliptic systems with homogeneous Dirichlet boundary conditions by the monotone iteration method. The existence and uniqueness of the positive solution of such a system are proved. In particular conditions which ensure that the iteration process converges to the unique solution are given.     

三阶非线性边值问题的正解存在性与唯一性

研究了一类含参数的非线性三阶边值问题,利用不动点指数理论并结合Green函数估计,在适当条件下证明了其正解的存在性与唯一性.     

Volterra型积分微分方程非线性边值问题解的存在性和唯一性

本文利用上下解方法得到了带Ｖｏｌｔｅｒｒａ型积分算子的非线性边值问题，ｕ＾ｎ＝ｆ（ｔ，ｕ，ｕ′，Ｔｕ），ａ１ｕ（０）－ａ２ｕ′（０）＝Ａ，ｂ１ｕ（１）＋ｂ２ｕ′（１）＝Ｂ解的存在性和唯一性。     

黎曼流形上一类非线性抛物方程的Hamilton 梯度估计

本文我们得到了黎曼流形上一类非线性抛物方程的局部Hamilton梯度估计. 利用这个局部估计,我们得到了一个Harnack型不等式和一个Liouville型定理.     

The First Initial Boundary Value Problem for Parabolic Hessian Equations on Riemannian Manifolds

For a class of elliptic Hessian operators, one type of corresponding parabolic Hessian equations is studied on Riemannian manifolds. uniqueness of the admissible solution to the first initial boundary the equations are shown. The existence and value problem for     

紧致黎曼流形上一类非线性热方程的梯度估计

In this paper,we study gradient estimates for the nonlinear heat equation ut-△u =au log u,on compact Riemannian manifold with or without boundary.We get a Hamilton type gradient estimate for the positi...     

Second Order Estimates for Non-Concave Hessian Type Elliptic Equations on Riemannian Manifolds

In this paper, we derive second order estimates for a class of non-concave Hessian type elliptic equations on Riemannian manifolds. By applying a new method for $C^2$ estimates, we can weaken some conditions, which works for some non-concave equations. Gradient estimates are also obtained.     

Riemann流形上的抛物型Monge-Ampère方程

This paper deals with a class of parabolic Monge-Ampère equation on Riemannian manifolds. The existence and uniqueness of the solution to the first initial-boundary value problem for the equation are established.     

一阶完全非线性常微分方程的周期粘性解

本文在适当的自然结构条件下证明了完全非线性常微分方程F(t,u(t),u′(t))=0的周期粘性解的存在唯一性.     

关于黎曼流形上的一个扩散方程的一些梯度估计

我们给出关于黎曼流形上的扩散方程θtu=Δu-▽φ·▽u（这里φ是一个C^2函数）的一些梯度估计。这推广了R.Hamilton和Qi S.Zhang关于热方程的一些梯度估计。     

Boundary Value Problems for the Stationary Schrodinger Equation on Riemannian Manifolds

We suggest a new approach to the statement of boundary value problems for elliptic partial differential equations on arbitrary Riemannian manifolds which is based on the consideration of equivalence classes of functions on a manifold. Using this approach, we establish some interrelation between the solvability of boundary value problems and solvability of exterior boundary problems for the stationary Schrodinger equation. Also we prove the comparison and uniqueness theorems for solutions to boundary value problems in this statement and obtain sufficient conditions for solvability of boundary value problems when the coefficient in the Schrodinger equation is changed.     

The Yamabe Problem and Applications on Noncompact Complete Riemannian Manifolds

We let (M,g) be a noncompact complete Riemannian manifold of dimension n 3 whose scalar curvature S(x) is positive for all x in M. With an assumption on the Ricci curvature and scalar curvature at infinity, we study the behavior of solutions of the Yamabe equation on –u+[(n–2)/(4(n–1))]Su=qu ^{(n+2)/(n–2)} on (M,g). This study finds restrictions on the existence of an injective conformal immersion of (M,g) into any compact Riemannian n -manifold. We also show the existence of a complete conformal metric with constant positive scalar curvature on (M,g) with some conditions at infinity.