查询词典 second boundary value problem

On one hand, the grain boundaries are the sites of microcrack nucleation, microcracks first occur at grain boundary zone, whose propagation type depends on lamellar orientation of both side of grain boundary.

一方面，微裂纹首先萌发于晶界区，其扩展方式取决于晶界两侧片层的取向。

Boundary representation, involves actually drawing the boundary of the model so that it appears on the display of a graphics terminal.

界限表示法，介入实际上得出模型的界限，以便它在图形终端的显示出现。

Boundary features are the boundary lines of a group of points distributed on a fitting feature.

边界特徵之萃取理论是利用拟合特徵所给予之资讯，找出属於边界之点云资料，再由这些边界点云资料计算出边界特徵。

The total transmission ratio, the relationship between basic transmission ratio and closed transmission ratio and their influences on efficiency were studied on the H typed closed epicyclic train, and the expression of boundary region of basic transmission ratio under conditions of satisfying the allowable efficiency was gained and the boundary curve was drawn.

研究了H封闭式周转轮系总传动比、基础传动比与封闭传动比之间的关系及其对效率的影响，得到了在满足许用效率的条件下基础传动比边界区域表达式，绘出了边界曲线。

The improved e-N method can also yield results well agree with those obtained by DNS.4 The transition prediction for boundary layers on cones with different key parameters such as angle of attack, cone half angle and the Mach number of the coming flow, have been made, to show the reliability of the modified e-N method.5 For the calculation of base flow, boundary layer equations can be used in the case of small angle of attack.

但是它要依赖于对初始扰动的正确预估，这显然又取决于更多飞行数据的积累和分析。e-N方法的转捩预测结果与直接数值模拟得到的结果也吻合较好。4通过对不同来流攻角、不同半锥角和不同马赫数的三维圆锥边界层的转捩位置进行预测，证实了改进的e-N方法对于三维边界层转捩预测是可靠的。5对于基本流的计算，边界层方程可以用于小攻角的情况，其计算量远远小于直接数值模拟，但背风面的剖面不可靠。

According to the studied results at present, the studied objects are mainly thin plate and beam about sound radiation mode, a method computed sound radiation mode of complex structure is presented in this dissertation, according to the results of the previous two chapter, a theoretical method to solve acoustical radiation mode and acoustical radiation efficiency of complex structure by boundary element method and acoustical radiation theory is posed, the acoustical radiation power is expressed as a Hermitian quadratic form, while the radiation modes is determined by general eigenvalue decomposing, and then the radiation efficiency is computed via the orthodoxy of radiation modes with regard to impedance matrix and average velocity matrix; lastly, the validity of the method is proved by pulsating sphere and radiating cube with analytical results. According to results of the form three chapter, the structure sound radiation sensitivity is studied in detail, the sound radiation power of structure can be expressed as positive Hermitian quadratic form, the sound radiation sensitivity can be expressed as two parts by partial differential with respect to design variable, which are sensitivity of boundary velocity and impedance matrix, combined with the theory of FEM and BEM, the structure sound radiation can be translated to the analysis of structure dynamic sensitivity and impedance matrix sensitivity. The theory posted in this dissertation is tested by the FEM software ANSYS and the software AAS programmed by author.

在前几章的基础上，通过结构声辐射的模态理论对结构的声辐射的机理进行了深入地探讨，针对目前声辐射模态的研究对象主要是简单的板和梁类结构，提出了一种计算复杂结构声辐射模态的方法，利用前两章研究所得的结论，将边界元方法与广义特征值的理论结合起来研究了复杂结构的声辐射模态与声辐射效率，先将结构的声辐射功率表示为一个正定的厄米特二(来源：ABb7C论文0909网www.abclunwen.com)次型，运用广义特征值分解求解了复杂结构的声辐射模态，然后利用声辐射模态关于阻抗矩阵与均方速度耦合矩阵的正交性，求解了复杂结构的声辐射效率，最后用具有解析解的脉动球与辐射立方体验证了该方法的有效性。

However the lower order traditional absorbing boundary conditions are only effective for the incident waves with smaller incident angles. A fourth-order absorbing boundary condition equation based on Higden's ABC is deduced in this thesis, and a new algorithm is presented to automatically select the Higden's parameters.

本文基于Higdon提出的吸收边界条件方法，推导出四阶吸收边界条件方程，并提出了一种新的吸收边界条件角度参数的自动选择方法，使该吸收边界条件能够吸收全角度(0～90度)入射波。

By using them, we can discuss the theory of holomorphic functions on domains: the characterization of zeros sets of holomorphic functions on the boundary, the characterization of A infinity interpolation sets on the boundary, etc.

对于复椭球和广义复椭球，我们给出了其全纯支撑函数的估计，构造了边界上的拟距离，并用这些结果来研究域上的解析函数论：边界上解析函数零点集的刻划，A无穷插值集的刻划等。

Based on wave propagating in three directions of elastic foundation, vibrating displacement could be assumed to be in three forms along three directions. Hooke's law and theory of waves were adopted to deduce the formula of coupled viscous boundary. The coupled viscous boundary could be applied in finite element method.

根据波在地基的3个方向都可以进行传播的特点，假定了地基中质点沿3个方向的振动表达式，通过胡克定律和波动理论，推导了弹性地基中三维动力问题的耦合粘性边界的公式。

Numerical experiments show that because Navier-Stokes equations at highReynolds number are a hyperbolic system,the boundary conditions are appli-cable to prescribe their boundary problems.

数值实验表明，在高Reynolds数下，由于Navier-Stokes方程呈现出很强的双曲型方程的性质，上述经过某些线性化处理得到的无反射边界条件是可以用来指定其边界值问题的。

"Second Life is remarkably easy to work with, and is very popular,"

"第二次生命是显着容易的工作，并且很受欢迎，"

For example, we usually assume that materials are homogeneous and isotropic and free of internal defects or flaws.

为了得到适合有限元分析的模型，我们必须经过如图2所示的简化步骤。