条件方程

It is concluded that the nonclassical symmetries of the nonlinear partial differential equations can be derived by using the compatibility between the original equation and the invariant surface condition.

由此，得到了利用不变条件及初始方程的相容性也可求得非线性偏微分方程的非古典对称的决定方程的重要结论。

As for nonhomogeneous equation, the method of integrating coupling pressure and momentum equation is adopted.

对于非齐次方程采用了压力耦合和动量方程联立求解的方法，算出的结果和解齐次方程在同样的初值和边界条件下，相差不大。

The main results and novelties of the paper are as follows:Firstly, we study the existence of nontrivial solution for the following nonlinear equations with singular pontential By using variational methods and critical point theory, we construct linking type critical value of this kind of singular elliptic equations, with the properties of the eigenvalue, we estimate the critical value and prove the local condition holds to show the existence of the nontrivial solution.

论文的创新点及主要结果如下：首先研究有界区域上具有奇异位势的非线性方程的非平凡解的存在性，运用变分方法与临界点理论，构造这一类奇异椭圆方程的环绕型临界值，并由特征值的性质给出临界值的估计，同时证明局部条件成立，最终证明方程非平凡解的存在性。

The existence of global weak solution for a class of generalized Ginzburg-Landau equations with an inhomogeneous boundary condition was studied. Some integral indentities of smooth solution of inhomogeneous initial boundary value problem of Ginzburg-Landau equations were deduced, by which a priori estimates of the square norm on boundary of normal derivative and the square norm of partial derivatives were obtained.

研究具非线性边界条件的一类广义Ginzburg＿Landau方程解的整体存在性·推导了Ginzburg＿Landau方程的非齐次初边值问题光滑解的几个积分恒等式，由此得到了解的法向导数在边界上的平方模以及解的平方模和导数的平方模估计；通过逼近技巧、先验估计和取极限方法证明了Ginzburg＿Landau方程的非齐次初边值问题整体弱解的存在性

Through creating a differential equation whose oscillation is equivalent to the impulsive equation, or considering the relation between impulsive points and delay, we get some sufficient conditions for the oscillation of the equation.

第二章讨论了二阶自共轭脉冲微分方程，通过建立与之振动性等价的微分方程，或考虑脉冲点与时滞间的关系，我们得出方程振动的一些充分条件。

Finally we consider the half-linear neutral delay dynamic equation A comparison result for the oscillation between the equation and a first order delay dynamical inequality is established.

在本章最后，考虑半线性中立型时滞动力方程建立了方程的振动性与一个一阶时滞动力不等式振动性的比较结果，在此基础上，给出了方程所有解振动的几个充分条件。

The algorithm has following properties: Although the merit function has the form of least squares of a system of overdetermined equations, in the Newton equation of our algorithm, only the coefficient matrix of the system of overdetermined equations is used instead of its product as in Guass-Newton method for solving the least squares problems. That is, our Newton method is more like that for the system of nonlinear equations rather than that for LSPs. The global convergence is obtained for VLCP with vertical block P_0 + R_0 matrix; The local quadratic convergence rate is proved under the condition that the solution is BD-regular; Although there is only a Newton equation in our algorithm, the finite convergence property can be shown if matrix is vertical block P— matrix (without the hypotheses of strict complementarity).

该算法具有下列特点：所构造的价值函数虽然具有超定方程组的最小二乘问题的形式，但在基此建立的Newton算法中，其Newton方程的形式更象非线性方程组的Newton法中的Newton方程，仅利用了超定方程组的系数矩阵本身的信息，避免了一般最小二乘问题的Guass-Newton法中必须计算系数矩阵的乘积的工作量；对竖块P_0+R_0矩阵的垂直线性互补问题，算法具有全局收敛性；在解是BD-正则条件下，证明了算法的局部二次收敛性；虽然算法只含一个Newton方程，但对竖块P-矩阵垂直线性互补问题，算法具有有限步收敛性。

This article bases on the knowledge of ordinary differential equation, mathematical and physical equations and equation of reactive pervasion. It researches the blow-up critical exponents of heat conduction type which is parabolic equations with nonlinear boundary constraints.

本篇论文以常微分方程与数学物理方程，反应扩散方程的知识为理论基础，讨论了热传导问题的临界指数问题，该问题是一个带齐次边界条件的非线性抛物型问题。

Chapter 2, we investigate the existence of multiple positive solutions of the neutral partial difference equations on the base of the existed results of partial difference and difference equations, and obtain some sufficient conditions for the existence of multiple positive solutions.

第二章，基于已有的偏差分方程和差分方程的结果，我们研究了高阶非线性中立型偏差分方程多正解的存在性问题，建立了判断多正解存在的充分条件，对前人的结果进行推广。

Therefore,it is necessary to research diffusion equation for suspended sediment because it describes the sediment move process in the water body.The equation is a various coefficients second-order linear partial differential equa-tion,such equation under complex boundary condition is very difficult to get its analytical solution,while its numerical solution relative analytical solution is more easier and has the obvious superiority:simple,the computation convenience.but to get a kind of difference format which is good accuracy and stability is not easy.

泥沙扩散方程实际上是一个变系数的二阶线性偏微分方程，这样的方程在各种复杂边界条件下求解是十分困难的，求它的解析解在数学上存在着难以克服的障碍，无法求出其精确解，因此常用数值方法求它的近似解，相比较而言，数值方法有着明显的优势：即简单灵活、计算方便快捷，但要寻找一种精度高、稳定性好、计算方便的差分格式也并非易事。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。