域的内部

Based on the covering-domain method, an expression for calculating the interior scattering sound field of an arbitrary-shaped closed thin shell in which there are some scatterers is given theoretically.

应用覆盖域方法从理论上研究了复杂形状封闭薄壳内部存在散射体时的内部散射声场。

Based on the covering-domain method, an expression for calculating the interior scattering sound field of an arbitrary-shaped closed thin shell in which there are some scatterers.

复杂形状；散射声场；散射体；封闭薄球壳；基于覆盖域的思想和方法，本文给出了复杂形状封闭薄壳在内部存在散射体时的内部散射声场计算表达式。

Some curvilinear grid generation examples show that the proposed adjusting factors ideal grids can be formed for simple connected regions and connected regions with complex boundary. The curvilinear grids near boundaries are orthogonal ...

实例检验表明，该调节因子能够对复杂边界的单连通域或多连通域的水域生成理想的曲线网格，即边界处网格正交，内部网格分布能够适应物理量场的变化情形。

The first one is an algorithm with terminal sliding mode equality constraint. The second is a dual-mode control scheme, which enlarge the terminal region. The sliding mode based MPC is implemented while system state is outside of terminal region, and sliding mode variable structure control designed off-line is used once system state arrives in the terminal region.

第一种方法为终端滑模等式约束非线性模型预测控制方法，首先离线设计切换函数使得滑动模态渐近稳定，然后在有限预测时域的基础上对切换函数附加一个终端等式约束；第二种方法为双模控制方案，在终端区外采用模型预测控制，使得系统状态在有限时域内到达终端区内；在终端区内部采用离线设计的滑模变结构控制，使得系统渐近稳定。

The method is finding an interior point in the feasible region, followed by the central path, we can find a approximate optimal solution.

该算法从运输问题可行域的内部出发，沿着中心路径的方向，通过反复迭代寻找运输问题的近似最优解。

Moreover, It's proved that if the initial point is the interior point of hypercube and steplength is confined to (0,1) when carrying out one dimension search following the direction mentioned above in order to generate next point, then any point generated by such iteration is interior point of feasible field.

在求解加辅助项模型的过程，作者找到一个很好的下降方向，并证明了只要初始点在超方体的内部选取，沿着上述的下降方向进行一维搜索时的步长限定在(0，1)范围内，那么迭代点始终保持在可行域内部。

The structure of model changed little with different mesh. In most cases these mesh is geometrically fairly simple.

计算域的边界有固壁边界、计算域开边界、动边界及内部工程边界，对这些边界的处理本文有较详细的讨论。

Secondly, method of Taylor series is used to approximate the slow manifold and the O approximation of the slow manifold is given; slow dynamics such as saddle node bifurcation which has been proven to be the same as that for the full system is analyzed; at the same time, fast dynamics including bifurcation conditions and domain of attractor of the stable equilibrium are also analyzed; the attracting region which consists of the stable manifold of the unstable equilibrium and stable equilibrium is given; we found that when the inner flux decay increases, the domain of attractor is enlarged.

首先，给出了电力系统SMIB模型的时间尺度分解，得到标准的奇异摄动模型；其次，利用幂级数方法，给出了慢流形的O近似M〓，分析了在慢流形M〓上的慢动态，得到了慢子系统的鞍结分支值，并证明此分支值与原系统的鞍结分支值相同；分析了快子系统的平衡点和全局分支的存在条件，给出由不稳定平衡点的稳定流形与稳定平衡点形成的吸引域；并研究内部电压对稳定域的影响，发现稳定域随内部电压增加而扩大；最后给出整个系统的稳定平衡点的近似吸引域。

The following exciting results are revealed: 1 When considering the influence of some nonlinear elements such as hard-limit of exciters, the effects of some devices such as Power System Stabilizer and Static Var Compensator which can introduce positive damping in power system, the reasonability of system parameter values in simulation, the SNB surface and HB surface on the boundary of SSSR will turn close to each other and even coalesce together; 2 Under some conditions, coupling between slow exciters and shunt capacitors will bring negative damping in power system dynamics, which increases the possibility of oscillatory instability. So the power system with mass shunt compensators is easily subjected to the oscillatory instability. In recent years, chaotic phenomena of power system have been reported many times. Some simulation studies even found chaos existing inside the power system SSSR. In this dissertation, chaotic phenomena in power systems are thoroughly studied in order to make clear the relation of chaos and SSSR. The following results are derived: 1 Based on Li-Yorke Theorem and their definition on the chaos, the existence of chaos in power system is verified; 2 Three possible routes of causing chaos in power system are found and deeply investigated. They are route of cascading period doubling, route of directly initial energizing and route of torus bifurcation (or quasi-periodicity). The latter two routes are investigated for the first time in power system stability studies; 3 When the stability conditions of chaos are broken, it is found they can lead to voltage collapse, angle divergence, or voltage collapse with angle divergence simultaneously.

针对在电力系统小扰动稳定区域内可能存在混沌吸引域的有关报道，本文深入研究了电力系统混沌现象的出现途径和与系统失稳模式之间的关系：1利用Li-Yorke定理和Li-Yorke的混沌定义，从理论上证明了电力系统混沌现象的存在性；2发现了电力系统中导致混沌出现的三种可能途径：倍周期分岔导致混沌、初始能量直接激发混沌和经由环面分岔导致混沌，并对后两种新发现的途径进行了较为细致的研究；3发现了混沌极限环破裂导致电压崩溃、角度失稳以及电压崩溃和角度失稳同时出现的现象，其中混沌极限环破裂导致系统角度失稳和电压崩溃及角度失稳同时出现的现象均属首次报道；4证明由微分-代数方程描述的系统模型，其小扰动稳定域的边界只包含HB、SNB和SIB三种分岔界面，在SSSR的内部和边界上，均不可能存在会导致混沌的点，从而将混沌现象排除在小扰动稳定域的研究之外，简化了后者的研究工作。

As for the interior literary phenomenon, a specific structual co-sourse relation was formed by the literature field and social space composed of above-mentioned interllectuals, therefore, when scholoars started to transform the consumption of desire toward Geishas mentioned above into character writing and works, the whole mechanism of literature field can begin to take place.

就内部文学现象而言，由知识份子所组成的文学场域与上述的社会空间形成一种特定的结构性同源关系，是故当文人们开始将上述对艺旦的情欲消费化为文字书写与创作时，整个文学场域的机制便得以开始启动。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。