有限维的

This thesis contributed to the comprehensive study of the Finite-Difference Time-Domain method and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies. The work includes mainly three parts: the study on the performance of PML absorbing boundary condition applied to pseudo low frequency electromagnetic problems; the validation of the FDTD method with PML absorbing boundary conditions and the corresponding computer software based on the numerical study of the electromagnetic field of an electric dipole antenna, and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies; the development of an improved alternating direction implicit finite-difference time-domain method.

在综合前人工作基础上，本文对时域有限差分法及其在开关电源辐射电磁场数值计算中的应用进行了系统的分析和研究，其核心内容包括：伪低频电磁场数值计算中PML吸收边界条件性能的研究；基于基准问题—电偶极子天线三维辐射电磁场，验证了本文构造的基于PML吸收边界条件的三维FDTD法及其计算软件，并应用于高频开关电源辐射电磁场的数值分析；提出了一种改进的交替方向隐格式时域有限差分法。

The inconsistencies of dimensional reduction and naive dimensional regularization in dealing withChern-Simons-matter theory are analyzed.The consistent dimensional regularization combiningwith higher covariant derivative regularization is adopted to consider Chern-Simons field theorycoupled to complex scalar and spinor field.All the local parts of one-loop two-point functionsand three-point functions are computed.Slavnov-Taylor identity is combined with these explicitcalculation results to give the one-loop local effective action.The finite gauge invariant quantumcorrection is shown and finite wave function renormalization constant for each field is defined.Thelocal part of one-loop three gauge field vertex is especially evaluated and it is verified that thereexists a renormalization choice compatible with BRST symmetry.

然后计算了所有的两点函数和三点函数单圈修正的定域部分，利用S-T恒等式给出了单圈定域有效作用量，定义了场的重正化常数，发现物质场和规范场都存在有限的规范不变的量子修正，并讨论了这些有限的规范不变的量子修正的物理意义，进而通过考察单圈三规范场顶角，表明存在与BRST对称性相容的重正化选择。5、在背景场方法的框架下，选择高阶协变导数正规化与维数正规化的杂化正规化方案计算了背景场两点函数的两圈量子修正，结果表明，标志紫外发散的极点项恰好抵消；进一步利用背景场方法中明显的规范对称性，证明背景场三点函数的两圈图贡献也是有限的。

The coordinate transformation and numerical integration was executed on the discretized tetrahedral elements based on which the 3-D MT vector-finite element method was implemented. A whole computation framework for 3-D vector-finite element method with unstructured mesh was given. Based on this some typical models were tested which has demonstrated that our algorithm could distinctively avoid problems caused by the fake solution and both the accuracy and efficiency were enhanced which made our algorithm has a bright future for further application.3. According to theory of Sobolev vector space and the discretization of Helmholtz space, the error estimate which was suitable for 3-D MT vector-finite element modeling was deduced by which the procedure of adaptive technique was guaranteed.4. Based on the fully unstructured tetrahedralization and optical strategy, the 3-D magnetotelluric h-adaptive vector-finite element method was presented through combining the error estimate. With this work, the accuracy and creditableness for 3-D MT complicatedly modeling was guaranteed.5. The 3-D magnetotelluric h-adaptive vector-finite element algorithm with unstructured mesh was implemented.

针对非结构化的四面体单元，采用坐标变换和数值积分方法，实现了MT三维矢量有限单元分析，建立起基于非结构化网格的三维MT矢量有限元计算流程，并对典型模型和国际标准电磁模型进行了数值模拟，结果对比和分析表明，基于非结构化网格的三维MT矢量有限元不仅消除了节点型有限元的伪解，而且具有很高的计算精度和速度，有广阔的应用前景。3、根据Sobolev函数的向量空间和Hemlholtz空间的分解，推导出基于残差的三维大地电磁矢量有限元后验误差估计公式，为三维大地电磁自适应矢量有限元数值模拟的实现奠定了基础。4、在完全非结构化四面体单元剖分及优化基础上，结合三维大地电磁矢量有限元后验误差估计公式，提出了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算策略，保证了对复杂大地电磁模型数值计算的精度和可靠性。5、实现了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算流程，对典型模型和国际标准电磁模型进行了数值模拟。

On the other hand, Let M~n be an z-dimensional complete noncompactoriented submanifold with finite total curvature in an-dimensional simplyconnected space form F~ of constant curvature c. In this thesis, we provethat if M satisfies one of the following: n≥3, c=0 and integral from n=M H~n＜∞;n≥5, c=-1 and H＜1-2/n~(1/2); n≥3, c=1 and H is bounded, where Hdenotes the mean curvature of M. then the dimension of the space of L~2 harmonic1-forms on M is finite.

本文还证明：若具常曲率c的完备单连通空间型F~中具有有限全曲率的n维完备非紧可定向子流形M满足下面条件之一：n≥3，c=0且integral from n=M H~n＜∞；n≥5，c=-1且H＜1-2/n~(1/2；n≥3，c=1且H有界的，则M上L~2调和1-形式空间的维数是有限的，这里H为M的平均曲率。

Using finite difference time domain method, the electromagnetic field distribution of THz wave is simulated in a THz 2D PC splitter and by plane wave expansion method the dispersion relation and defect modes are achieved in a THz rotated PC waveguide.5. A woodpile three-dimensional (3D) PC with face-centered-tetragonal symmetry is one of the most popular 3D PCs because of its favorable band gap characteristics. Based on the woodpile fct lattice structure, we propose a novel woodpile THz lattice structure with comparatively decreased symmetry, better band gap properties and easy fabrication by varying some structure parameters.

计算结果为利用非线性光学差频方法产生THz辐射源的实验研究提供了深入和全面的理论基础；四、利用平面波展开法，通过改变二维THz光子晶体的结构参数，对二维THz光子晶体完全带隙进行了优化，分析出两种适合工作在THz波段的二维光子晶体结构；采用时域有限差分法和平面波展开法，计算出THz波在二维光子晶体"T"型分束波导，45度旋转波导中传输的电磁场分布以及缺陷模；五、Woodpile面心立方四角结构是三维光子晶体中被研究最广泛的结构之一。

Numerical dispersion characteristic and impedance relationship of three dimensional perfectly matched layers are analyzed under finite difference approximation in this paper, respectively, which show that numerical dispersion relationship of PML is different from that of the FDTD equations and the impedance of homogeneous PML medium is the same as that of free space.

本文分别分析了有限差分近似下三维理想匹配层的数值色散特性和阻抗关系，分析表明，理想匹配层的数值色散关系有别于时域有限差分方程的数值色散关系；有限差分近似下，均匀理想匹配层媒质的阻抗和自由空间的阻抗相同。

In the paper, river and the downstream area of dike are regarded as a whole system, and hydraulic model of coupling 1-D river and gradual dike-break is established, therein the Preissmann implicit difference scheme is applied to Main River, and the FVM is applied to the breach and polder. On the basis of FVM and unstructured grids, TVD ?

本文将河道与堤坝下游区域视为一个整体，对于单一河道采用Preissmann四点隐式差分格式计算，对于溃口及圩区采用有限体积法，建立了一维河道与堤坝渐溃耦联的水力模型，也是一维、二维耦合的水流模型。

Let M~n(n≥3)be an n-dimensional complete noncompact oriented submanifold in an-dimensional Euclidean space R~.

他们还进一步证明：若M具有有限指标，则M上L~2调和1-形式空间的维数是有限的，且M仅有有限个端[35]。

Through the hypersingular integral equations of 3-d crack perpendicular to the interface given in the preceding, the principles of finite-part integrals and of limit are further made use of to pick the hypersingular integral equations of 3-d crack terminating at the interface On the basis of the equations, starting strictly from 3-d theory of elasticity, stress singularities of intersection-line near the front edge of the 3-d crack terminating at the interface are analyzed by virtue of dominant-part analysis of 2-d hypersingular integrals.

根据前面所得到的与界面垂直的单片裂纹超奇异积分方程，进一步运用有限部积分原理和极限理论，推导出了与界面垂直相抵的三维平片裂纹的超奇异积分方程。在此基础上，严格从三维理论出发，使用二维超奇异积分的主部分析方法，对与界面垂直相抵的三维平片裂纹前沿交线上的应力奇性指数进行了分析。

This paper reviews and summarizes the progress in this field as follows: the mathematical model and the difficulty of the analytical solutions is introduced; discusses the latest progress of the numerical solutions is discussed; the finite difference method, the Godunov method, the Boltzmann method, and the KFVS method of one-dimensional dam-break problem are introduced; the TVD method, the discontinuous finite element method, the finite volume method and characteristic method of two-dimensional dam-break problem are discussed; the applicability, the advantage and the disadvantage of each method are analyzed; and the progress in the numerical calculations of flow of fluid with free surface are presented.

回顾和总结了国内外对溃坝水流演进问题的研究进展：介绍了溃坝水流的数学模型及解析解法存在的困难，进而讨论了数值解法的最新进展；论述了求解溃坝水流一维问题的有限差分法、近似黎曼解的Godunov格式法、Boltzmann法、KFVS法和二维问题的TVD格式法、间断有限元法、有限体积法、特征线法，并分析了各种方法的适用范围和优缺点，及讨论了限制函数的使用；介绍了利用自由水面追踪方法计算溃坝水流的研究进展，并根据目前存在的不足和实际工程的需要，提出了进一步研究的方向和发展趋势。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。