查询词典 dirichlet boundary condition

Both the Dirichlet boundary conditions and the Neumann boundary condition are considered.

分Dirichlet和Neumann两种边值条件进行了讨论。

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 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。

In Chapter 3, The existence of a bounded global attactor for Olmstead model with homogeneous Dirichlet boundary condition is proved under some condition on the parameters.

第三章讨论了带齐次Dirichlet边界条件的Olmstead模型的有界吸引区域的存在性。

Finally, we give some examples.In Chapter 3, The existence of a bounded global attactor for Olmstead model with homogeneous Dirichlet boundary condition is proved under some condition on the parameters.

本章分四个部分，第一部分是对问题的概述；第二部分讨论了扩散系数对具有无穷时滞的一维竞争扩散系统的空间一致定态解的稳定性的影响，将扩散系数d作为分支参数，我们证明了从d_0处当d

Through the photographic technology of fisheye lens and achieved the space image of cotton canopy structure distributing at different condition, and setupped cotton canopy structure base after image analysis. The experiment results indicated that the adaptability of different varieties to plant density is different, reasonable plant density is benefit to the raise of varieties product, and Xinluzao10 is better at high density（225000plant/ hm2） condition and Xinluzao12 is better at mid-high density（150000 plant / hm2） condition. For different nitrogen, Xinluzao10 is better at right nitrogen application amount（600 kg/ hm2） condition and Xinluzao12 is better at mid-high amount（900kg/ hm2）condition. For different irrigation, Xinluzao6 and Xinluzao12 is better at limited drip irrigation amount（1500 m3/ hm2） condition and Xinluzao8 Xinluzao13 is better at right drip irrigation amount（3000 m3/hm2） condition.

利用鱼眼镜头照相技术获取了不同处理棉花冠层分布空间图象，对图像进行处理分析，建立了棉花冠层图像库及分析诊断指标，研究结果表明，不同品种对种植密度适应性不同，合理的配置种植密度有利于品种的产量潜力的挖掘，高密（225000plant/ hm2）条件下选择新陆早10号、中高密（150000 plant / hm2）条件下选择新陆早12号栽培种植较为适宜；对于不同氮肥用量，适量氮肥用量（600 kg/ hm2）条件下选择新陆早10号、中高氮肥用量（900kg/ hm2）条件下选择新陆早12号较为适宜；对于不同灌水量，限量滴灌（1500 m3/ hm2）条件下选择新陆早6号、12号种植较适宜，适量滴灌（3000m3/hm2）条件下选择新陆早8号、13号种植较适宜。

Firstly, the existence and uniqueness of the solution for neutral stochastic functional differential equations with infinite delay under the uniformly Lipschitz condition, linear grown condition and contractive condition can be directly derived; And the moment estimate of the solution and the estimate for error between the approximate solution and the accurate solution can be both given; If the uniformly Lipschitz condition is replaced by the local Lipschitz condition, the existence and uniqueness theorem can be gained; Meanwhile, the existence and uniqueness of the global solution in the interval 0,+∞ can also be obtained; Secondly, L~p-exponential estimate of the solution for neutral stochastic functional differential equations with infinite delay can be studied; At length, the theorem of the local solution about neutral stochastic functional differential equations with infinite delay only under the local Lipschitz condition and the contractive condition can be established.

首先，在一致Lipschitz条件，线性增长条件和压缩性条件下，直接得到了具无限时滞中立型随机泛函微分方程解的存在惟一性，并给出了解的矩估计，近似解与精确解之间的误差估计；将一致Lipschitz条件替换为局部Lipschitz条件，也得到了具无限时滞中立型随机泛函微分方程解的存在惟—性，同时，也给出了在整个区间0，+∞上具无限时滞中立型随机泛函微分方程解的存在惟一性定理；其次，也讨论了具无限时滞中立型随机泛函微分方程解的L~p指数估计；最后，在局部Lipschitz条件和压缩性条件下，建立了具无限时滞中立型随机泛函微分方程局部解的存在惟一性定理。

The structure of analytic solution space is obtained and general form of the analytic solution is presented by means of Dirichlet Series. The convergence of Dirichlet Series solution is discussed.

根据比例延迟微分方程的性质，我们构造了Dirichlet级数形式的解析解，证明了Dirichlet级数形式解的收敛性，获得了保证方程解析解渐近稳定的充分条件。

Looking to bounce back from defeat against Cesena last weekend, the Calabrian boss will be sticking to his tried and tested 4-3-3, with Lopez and Sedivic joined up front in Giampaolo's absence by either Nanni or Plasmati.

鉴于上周末对切塞纳的比赛中反败为胜，这支南方球队将会更坚持其一贯而有效的4-3-3阵型，洛佩斯和塞德维奇将取代受伤缺席的詹保罗，和纳尼或者帕斯马蒂中的一个搭档锋线。

Meanwhile, their exposure to the more freewheeling ways of the West broadened dramatically.

另外，西方较自由的生活方式对年轻人的影响增大。