查询词典 difference equation

Based on the continuity equation of groundwater and the normal velocity formula of free surface, taking element e as a subdomain R in the seepage flow domain R, according to variation principle, the finite element equation of seepage field can be obtained.

由地下水的连续方程和自由面的法向流速公式，把单元e作为渗流求解区域R上的一个子域ΔR，根据变分原理，得到岩土体渗流场有限元方程。

The equation of continuity is then used to further get a 2-order elliptical equation satisfied by sea surface elevation, and the unpenetrable condition at the shore wall of semi-closed sea area is also derived by means of tidal level.

然后利用连续性方程进一步得到了海面升高即潮位所满足的二阶椭圆型方程，进而导出了以潮位形式给出的半封闭海区岸壁不可穿透条件。

Furthermore, the energy density equation and the equation of heat conduction were compared.

在此基础上，考虑边界的反射作用，推导了有限大板的能量密度控制方程，得到了能量密度的近似解，并通过位移解得出了能量密度和声强的解析解。

The effects of three components of energy density on total energy density were analyzed. Furthermore, the energy density equation and the equation of heat conduction were compared.

根据小阻尼假设，推导了无限大板在简谐激励作用下能量密度的控制方程，建立了能量密度和声强之间的关系，得出了远场解的表达式。

Then the basic fundamental and method of the computation of thermal load of the heated parts of internal-combustion engine are elaborated, the deflective differential equation of heat conduction, basic equation and boundary condition of the theory of thermo elasticity and numerical computation by FEA are introduced.

接着阐述了求解内燃机受热零部件热负荷的基本原理和方法，介绍了热传导的偏微分方程、热弹性理论的基本方程和边界条件确定的原则以及用有限元法进行的数值求解。

According to axisymmetric unsteady heat conduction equation of orthogonal aniso tropic material and boundary conditions,the equilibrium equation of a system of finite elements is deduced with triangular element of high accuracy,and programs are designed.

根据均匀正交各向异性材料轴对称热传导方程及其边界条件，利用变分法及欧拉理论，选取 6 节点的高精度三角形单元类型，推导了一般轴对称非定常热传导有限元基本方程。并编制了相应的计算程序。

Many high-rise buildings can be simplied into variable cross-section cantilever beam, which equation of free vibration is variable coefficient differential equation of higher order and there is no general solving process for which in mathematics.

对这类方程，数学上没有提供一般的解法。本文采用的级数解法可求出任何变系数的四阶微分方程，在给定边界条件下的解。

Utilize auxiliary plane to solve the following problem: the point of intersection of lines, equation of the straight line, equation of the plane and the distance between lines in different planes.

利用构造辅助平面方法求：直线与直线交点；平面方程；直线方程；异面直线间距离。

The way of working out the problem of taking two line segments as the root of an equation is to link up monodic quadratic equation directly with geometry and establish the connection between them.

以两线段长为一元二次方程的根的问题的解法，是把一元二次方程与几何问题直接挂钩，沟通了几何与二次方程之间的联系。

The way of working out the problem of taking two l segments as the root of an equation is to link up monodic quadratic equation directly with geometry and establish the connection between them.

以两线段长为一元二次方程的根的问题的解法，是把一元二次方程与几何问题直接挂钩，沟通了几何与二次方程之间的联系。

Objective:To compare the response control and attention of Schizophrenic patients with that of the healthy controls by Integrated Visual and Auditorycontinuous performance test. To quantitate the impairment of cognitive function in patients, and to explore the relationship between cognitive function and the severity of the disorder.

目的：探讨精神分裂症病人在IVA持续操作测试中的反应控制能力、注意力等，并与健康人进行比较，从而量化精神分裂症病人的认知功能损害，并进一步探讨其认知功能与疾病严重程度的关系。

Main effective factors including subcooling degree, mechanical vibration, gas hydrate reformation, environment temperature, noncondensing gas and surfactant are analyzed.

指出过冷度、机械振动、重复生成水合物、环境温度、不凝性气体、添加剂是影响气体水合物生成的主要因素，还对R152a水合物的放冷进行了实验研究。