守恒

Af ter applying this result to the conservative gas dy2 namic systems ,the semi2discrete finite difference approximation and the discrete ent ropy couple [Ut , F0j + G1j ] is searched.

关于双曲型守恒方程组ut + f x = 0 ，若存在标量熵对满足熵不等式Ut + Fx ≤0 ，则原方程存在弱解。

Firstly , one energy conservative finite difference scheme for SRLW equation of two levels and two of three levels are proposed in this paper.

所提的格式严格保持了方程原来所具有的守恒律。

Thus, non-negative property is suggested as the criterion of stability. Further, diffusion coefficient is replaced by an artificial one in the finite difference equation to simulate the entropy generation can improve the accuracy of the numerical analysis.

在尽可能满足对流扩散过程数值格式中的输运性或守恒性及稳定性的同时，以扩散熵产仿真为原则的伪扩散系数可有效地提高数值模拟的仿真性，为数值计算中扩散系数的修正提供了一种有效的手段。

The finite difference equation was built by using elemental energy balance of reinforced concrete beam with three surfaces exposing to fire based on the thermal properties of concrete. The influence of the physical or chemical reaction of free or combined water in concrete on the temperature field of concrete was considered by magnifying the specific heat of concrete.

根据三面受火钢筋混凝土梁离散体积单元的能量守恒原理，建立了有限差分平衡方程，在合理确定混凝土热工参数基础上，采用增大混凝土质量热容的方法，考虑混凝土中自由水与结合水的物理化学反应对混凝土温度场的影响。

Since 1950 s, the research of numerical method for hyperbolic conservation laws is one of key research directions in computational mathematics. The finite difference method, specially TVD and ENO schemes, for hyperbolic conservation laws are very successful.

双曲型守恒律方程数值计算方法的研究，是二十世纪五十年代以来，计算数学中的一个重要研究方向。

In this paper, we consider hyperbolic conservation laws, and the following work has been done to the finite volume method on unstructured meshes :In preface , we introduce the backupground of the oringe of the finite volume method, and point out the limitation of the finite difference methods and the finite element methods, and import the finite volume method.

本文主要考虑双曲型守恒律方程，对二维非结构三角形网格有限体积方法作了如下工作：介绍了有限体积方法的产生背景，指出了有限差分方法和有限元方法中的特点，对有限体积方法的产生和发展给出了比较详细的分析。

It is verified that the dynamicequations of free-floating space manipulator systems can be linearlydependent on a group of inertial parameters.

系统动力学分析的结果表明，结合系统动量及动量矩守恒关系得到的系统动力学方程将为系统惯性参数的非线性函数。

Be able to understand the fundamental principles behind the conservation equations and identify the significance of each term in the governing equations.

能了解守恒方程式背后所隐含的基本定律以及确认方程式内各项之重要性。

It's easy to garble that the momentum conservation is law or theorem,in the teaching of the universalitly physics.

动量守恒是定律或是定理，这在普通物理的教科书中，往往会产生混淆。

A third order ENO finite volume method for hyperbolic conservation laws on unstructured triangular mesh is introduced.In order to obtain the third order accuracy on spatial discretization,a weighted quadratic interpolation is constructed on every triangular mesh.Two point Gauss quadrature formula is also used on each edge of every triangular mesh and the third order TVD Runge-Kutta method is used for time discretization.The numerical order of convergence and the numerical result of a mesh 3 wind tunnel with one step are given.

摘 要 基于双曲型守恒律方程，对非结构三角形网格给出了一种ENO(Essentially Nonoscillatory Scheme)型有限体积格式，方法的主要思想是先对每一个三角形单元构造一个加权的二次插值多项式，而在计算交界面的流通量时采用了两点高斯积分公式以保证格式的整体精度，时间离散采用三阶TVD Runge-Kutta方法。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷