查询词典 second boundary condition

Coordinate sequence method is made up of the instruct information of polygon boundary x, y coordinate. It is the easiest polygon vector encoding method. The file structure of this method is easy, but because of the polygon boundary has stored two times, it will produce data redundancy, moreover, short of neighbor threshold information; Tree index encoding method make all the boundary points digitizing, store the coordinate sequence, connect the point index to boundary line, and then connect the line index to other polygons, so as to the tree index structure has came into being. It eliminates neighbor polygons boundary data redundancy problems; Topology structure encoding method is a method which by setting up a complete topology relationship structure, resolve the neighbor threshold and island information process problem. However, it makes arithmetic more complicated and makes database bigger.

坐标序列法是由多边形边界的x，y坐标对集合及说明信息组成，是最简单的一种多边形矢量编码法，文件结构简单，但多边形边界被存储两次产生数据冗余，而且缺少邻域信息；树状索引编码法是将所有边界点进行数字化，顺序存储坐标对，由点索引与边界线号相联系，以线索引与各多边形相联系，形成树状索引结构，消除了相邻多边形边界数据冗余问题；拓扑结构编码法是通过建立一个完整的拓扑关系结构，彻底解决邻域和岛状信息处理问题的方法，但增加了算法的复杂性和数据库的大小。

The main creating aspects are finding and clarify such a fundamental physical process that the grain boundaries emit vacancies under compressive stress to induce solute non-equilibrium grain boundary dilution and absorb vacancies under tensile stress to induce non-equilibrium grain boundary segregation, formulizing the structural equations and the composition equations in force equilibrium in grain bounary region to describe this physical processes and the kinetic equations for non-equilibrium grain boundary segregation under tensile stress, calculating the modulus in grain boundary region from the expermental data of grain bounday segregation using the structure and coposition equations and calculating the diffusion coefficients of vacancy-solute atom complexes using the kinetic equation simulating the experimental results of grain boundary segregation.

本项目的主要创新点是，发现并阐明了弹性应力场作用下空位与晶界交互作用的基本物理过程：在张应力作用下，晶界会吸收空位，引起溶质非平衡晶界偏聚；压应力作用下，晶界会发射空位，引起非平衡晶界贫化。建立了描述此物理过程的晶界区力学平衡的结构方程和成分方程；？建立了张应力引起的非平衡晶界偏聚动力学方程？；用晶界区力学平衡的结构方程和成分方程？，首次通过实验测量计算出多晶材料晶界区的弹性模量；通过建立的动力学方程模拟实验结果，首次获得溶质原子－空位形成的复合体的扩散系数。

Compared with the known results,the nonlinearity is allowed to change sign and is involved with the first-order derivative explicitly.In particular,the boundary condition includes the Dirichlet boundary condition and Robin boundary condition.

与现有工作相比，我们所考虑的动力方程不但非线性项可变号，而且包含一阶导数项，所考虑的边值条件更具一般性，比如可以包含Dirichlet及Robin边值条件等。

Chapter 3 emphasizes on the case that the considered systems contain not only impulse but also time delay. We mainly investigate impulsive parabolic systems with time delay and neutral impulsive parabolic systems. Section 3.1 discusses the oscillation of impulsive parabolic systems with time delay under Robin boundary condition and obtains some useful criteria via first order impulsive differential inequalities with time delay. Section 3.2 studies the oscillation of neutral impulsive parabolic systems under Neumann boundary condition and Robin boundary condition, respectively, and obtains some sufficient conditions for oscillation and strong oscillation via first order neutral impulsive differential inequalities.

第三章针对于"脉冲"与"时滞"共存的复杂情形，仍采用反证法讨论了含时滞的脉冲偏微分系统的振动理论，具体研究了脉冲时滞抛物系统和中立型脉冲时滞抛物系统。3.1节考虑了脉冲时滞抛物系统的振动理论，借助于一阶脉冲时滞微分不等式的解的性质，得到了满足Robin边界条件的脉冲时滞抛物系统的若干振动准则；3.2节考虑了中立型脉冲时滞抛物系统的振动理论，借助于一阶中立型脉冲时滞微分不等式的解的性质，分别给出了满足Neumann边界条件和Robin边界条件的中立型脉冲时滞抛物系统的若干振动和强振动准则。

This method allows for a more accurate processing of boundary condition on the semiconductor layer in XLPE cable of stator winding than the standard finite element, so that the interlaminated issue of boundary condition on interface can be avoided. A general algorithm is applied to deal with both the Dirichlet and the periodic boundary condition in 2D or 3D magnetic field problem.

提出了用有限元法计算磁场问题时周期性边界条件和第一类边界条件的统一处理方法，利用该方法在不改变代数方程组阶数、保持系数矩阵性质不变和带宽基本不变的条件下，使两种强加边界条件能同时处理，简化了程序编制，并与寻址方法相结合，提高了计算速度。

Based on varying process of generator terminal parameters after excitation fault, shortages of excitation protective principle of static stability boundary and asynchronous impedance boundary are analyzed. It proposed that excitation fault research relates to large-disturbance stability. Because dynamic power-angle character of generator after excitation fault is non-sinusoidal, there are differences between dynamic power-angle character and static state power-angle character. So it isn't ideal to protective operation result based on small-disturbance stability and static stability boundary criterion. At the same time, it proposed that asynchronous boundary impedance criterion is a constant reactive power circle moving adown j Xd′. It can ensure complete loss-of-excitation generator measuring impedance enter into the circle, but can't ensure the other condition measuring impedance including impossible losing synchronism enter. So loss-of-excitation protection would be maloperation when system voltage drops short and recovers or generator rejects load.③Based on stability principle, it puts forward setting conditions and calculation method of generator loss-of-excitation protection by direct measuring power-angle.

以励磁故障后发电机端的相关参数的变化为基础，通过对以静稳定边界和异步阻抗边界作判据的两类三种现行励磁保护在原理上存在的缺陷分析，发现：励磁故障是一个大干扰稳定性问题，励磁故障后的发电机的动态功角特性与静态功角特性有很大的差异，已远非正弦曲线，因此基于小干扰稳定性原理、以静稳定边界作判据的保护必然动作不理想；异步边界阻抗判据是一个下移j Xd′的等无功阻抗圆，它可以保证完全失磁后的发电机测量阻抗能进入该阻抗圆，但不能保证完全失磁之外的其它状态不会进入该阻抗圆，因此在系统电压短时下降或发电机突然甩负荷等情况下可能启动该保护使之误动。

The results show that the absorbing effect of low-order Higdon absorbing boundary condition is undesirable and relatively strong boundary reflection exists in wave field snapshot and analog recording; the effect of traditional and improved PML absorbing boundary conditions are similar, which can effectively absorb and attenuate the boundary reflections from any angle.

结果表明，低阶Higdon吸收边界条件吸收效果较差，在波场快照和模拟记录中存在较强的边界反射；改进的PML吸收边界条件与传统的PML吸收边界条件效果相当，均能有效地吸收衰减任意角度的边界反射波。

Two problems were solved in numerical calculation, one was that a term of 1/r in Maxwell was divergence in cylindrical center where r=0, another was that the value of optical field at cylindrical center was difficult to decided when the cylindrical center set as a boundary condition in Maxwell equation, So the values of optical field need just calculate from cylindrical center to cylindrical boundary, comparing from cylindrical boundary to cylindrical boundary, near upon half CPU time and RAM saved.

计算中解决了在圆柱中心线上Maxwell方程存在发散项1/r以及用圆柱中心线作为边界条件时，中心线上光场值难确定的问题，因而光场只需从圆柱中心计算到圆柱边界，和以圆柱的两条边做为边界条件比较，节省了将近一半的计算时间和计算机存储空间。

The author compares the effects of Dirichlet boundary condition and attenuation one on artificial boundary with that on transmitting boundary, so does the absorption effects, the author also demonstrates the advantage of transmitting boundary.

文中还就刚性边界条件、衰减边界条件对人工边界的影响及吸收效果与透射边界作了对比，验证了透射边界的优越性。

The establishment principles of traditional and improved PML absorbing boundary condition were described. Through numerical simulation, the absorbing effect of improved and traditional PML absorbing boundary and low-order Higdon absorbing boundary on boundary reflection was discussed.

阐述了传统和改进的PML吸收边界条件的构建原理，通过数值模拟讨论了改进和传统的PML吸收边界以及低阶Higdon吸收边界对边界反射的吸收效果。

Liapunov—Schmidt method is one of the most important method in the bifurcation theory.

Liapunov—Schmidt方法是分叉理论的最重要方法之一。

Be courteous -- even when people are most discourteous to you .

要有礼貌──即使当別人对你最不礼貌的时候。