查询词典 positive linear operator

This paper is devoted to solving linear saddle point problems, Specifically, We consider nonsymmetric systems, written as usual in block form, where the upper left block is an invertible linear operator with positive definite symmetric part. Such saddle point problems arise, for example, in certain finite element and finite difference discretizations of NavierStokes equations, Oseen equations, and mixed finite element discretization of second order convection-diffusion problems.

中文题名求解鞍点问题的迭代方法副题名外文题名论文作者冯丽红导师曹志浩教授学科专业计算数学研究领域\研究方向学位级别博士学位授予单位复旦大学学位授予日期2002 论文页码总数87页关键词鞍点问题迭代方法网格离散线性方程组馆藏号BSLW /2003 /O241 /15 论文针对鞍点问题的求解分析了一些典型的快速算法。

What most documents on asymptotically linear operator equations discussed are the existence of positive solutions.

到目前为止，作者只见到过对偏微分方程的变号解的讨论（见[15]，[16]），有关变号解的抽象结果还很少见。

We know that asymptotically linear operator equations have negative solutions and sign-changing solutions besides positive solutions, in this chapter, we obtain the existence of this three kind of solutions in Banach space, and we can know the concrete place of these solutions.

第三章的目的就在于借助于不动点指数理论利用一致正条件讨论非线性算子方程变号解的存在性，同时研究了变号解与一对正负解之间的关系，在一定条件下我们证明了：若算子方程x=Ax存在一个变号解，则它的正解和负解必定成对出现。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。