查询词典 finite difference approximation

In Chapter 3, by using the technique of finite dimensional approximation of Seiberg-Wittentheory, the equivariant K-theory and some other methods, we study the problem of topologicalrestriction when there are smooth groups acting on Spin 4-manifolds such as the alternatinggroup A_5, cyclic group Z_6 and symmetric group S_3 with actions of odd type, consequently weimprove Furutas 10/8 theorem under the condition of group actions.

第三章运用Seiberg-Witten理论的有限维逼近技巧和等变K-理论等工具，研究了Spin 4-流形X上分别存在光滑交错群A_5、循环群Z_6和奇型三阶对称群S_3作用时，X的拓扑限制问题，在群作用下改进了Furuta的10／8定理。

The boundary value problem for first-order differential equations with a parameter refers to the finite solution condition of equation which includes unknown quantity and its first-order derivative that not only relies on interval value but also relies on the parameter of the equation,which is always settled by fixed point theory or successive approximation method.

含一个参数的一阶微分方程边值问题是指：含有未知量及它的一阶导数的方程的定解条件不仅依赖于在区间端点的取值，而且依赖于方程中的参数。通常它用不动点定理或逐步逼近法来解决。

The mechanism of the least squares approximation that MFNN with finite nodes carried out on a given discrete point set is made, which, for the first time, results in an important theorem.

分析了有限规模多层前向网络用于离散点集上的最小二乘逼近的机理，首次给出了一个有关的定理。

Element-free Galerkin Method is a effective method for solving partial differential equations with the help of shape functions coming from moving least squares approximation. It is well-suited to problems involving large deformation and crack propagation etc on which Finite Element Method can not be used easily. But EFGM is computationally expensive and it is hard to impose the essential boundary condition. Coupling the EFGM and FEM can fetch up the defect of EFGM and improve the efficiency highly.

无网格伽辽金法是基于移动最小二乘法的一种用来求解偏微分方程非常有效的方法，在处理诸如高度大变形、裂纹动态扩展等有限元法较难解决的问题时有其独特的优势，但是存在处理边界条件复杂，计算量大的不足，将无网格法同有限元耦合可以解决这些缺点，极大的提高计算效率。

This thesis is concerned with metric Diophantine approximation for formal Laurent series over a finite base field.

我们将在本论文中探讨有限体下正规Laurent级数上的Diophantine逼近。

The finite summation of real Fourier series approximation of a time pusle.

时间脉冲的实部傅立叶级数接近的有限和。

Aapproximation of Fourier inverse integral using Fourier transform approximation for amplitude of harmonics in a finite Fourier series summation.

富氏级数中之谐波成份以富氏转换近似并以有限级数和近似富氏逆转换。

Taking advantage of gauge transformation and dipolar approximation, we qualitatively derive rotating Bose-Hubbard model.Then finite temperature phase boundary between superfluid phase and normal state in rotating Bose-Hubbard model is analytically derived by studying the stability of normal state in rotating bosonic optical lattice.We also analytically prove that as the function of rotation angular velocity the oscillation of critical hopping matrix directly follows the upper boundary of Hofstadter butterfly.

4通过做一个规范变换和偶极近似，定性地推导了旋转Bose-Hubbard模型，并且通过研究正常态不动点的稳定性推广了旋转Bose-Hubbard模型的零温相图到有限温度的情形；另外根据系统有效的能带宽度与旋转速度的关系(Hofstadter蝴蝶)，得到了系统的临界跃迁矩阵随旋转速度的改变展示谐振行为的结论。

With the idea of finite approximation, we study a new solution method for the satellite altimetry problem. Our result shows that if the continental part of the earth is sphere cap, then the solution of satellite altimetry problem can be transformed into a linear system of equations with variants of the coefficients of spherical harmonic series. We prove that the linear system of equations is separated about the orders of spherical harmonic series.

研究了球界面下卫星测高问题的解法，利用有限逼近方法得到了下列结论：若陆地部分是球冠，则卫星测高问题的解可以转换成关于球谐级数位系数的线性方程组，并且位系数的阶和次是以分离形式出现的，从而确保该解法具有实用意义。

In order to reasonably depict four basic problems with friction, one Coulomb friction new form in first Kirchhoff stress is proposed to deal with finite deformation problems, other Coulomb friction form in incremental mode to elastoplastic flow theory; Hilbert function spaces concerning elastoplastical problems with friction are established, so it makes all operations and calculations in the treatise standardized within the scope of reasonably topologic structure; In view of functional extremum, the equivalence between generalized variational inequalities principles in elastoplasticity with friction and corresponding basic problems are testified by inducing Lagrangian multipliers, so it provides a rationally theoretical basis for numerical methods in elastoplasticity with friction; From the viewpoint of variational inequality, the theory of generalized variational inequalities in elasticity and elastoplasticity with frictional constraint is studied, and the uniqueness and existence of the solution of FEM is proofed under the proposed conditions of stress compatibility, and them FEM approximation and a discrete solution are discussed; Based on the principles of generalized variational inequalities in elastoplasticity with friction, direct generalized variational inequalities methods is pretended, which is a natural generalization and development of direct variational methods; Using generalized variational inequalities methods, some examples in metal forming including plane deformation, upset and extrusion are analyzed and the results prove that all the theories and methods in the paper are right, feasible, accurate and advanced.

主要内容有：为了合理地描述金属塑性成形中摩擦约束弹性、弹塑性基本问题，提出和研究了有限变形下以Kirchhoff第一应力表示的Coulomb摩擦定律形式和弹塑性流动理论下以增量形式表示的Coulomb摩擦定律表示形式；系统建立了摩擦约束弹塑性问题的Hilbert函数空间，使本文规范在一个具有合理的代数拓扑结构内进行一切操作和运算；利用Lagrange乘子，从泛函极值的角度系统地阐述和论证了一系列摩擦约束弹性、弹塑性广义变分不等原理与相应的实际问题之间的等价性，它为处理摩擦约束的弹塑性力学数值方法提供了合理的理论基础；从变分不等式的角度出发，阐述了对应于摩擦约束弹性、弹塑性问题的广义变分不等式理论，首次提出了在应力相容性条件下，它的有限元解具有存在唯一性，进而讨论了其有限元近似及离散解法；基于摩擦约束弹塑性广义变分不等式原理，首次提出了直接广义变分不等式方法，这一方法是直接变分法的合理推广和发展；利用直接广义变分不等式方法对金属压力加工中的平面变形问题、镦粗、挤压等塑性成形问题进行了分析计算，验证了该理论和数值算法的正确性、实用性、精确性和优越性。

He has to relate with three women in the movie, and yet remain implicitly faithful to the unseen Lucinda.

让克劳德布里亚里成功地饰演试验了一个难度很大的角色：和三个女人打交道，但还要底下对观众未曾谋面的卢馨达保持忠诚。

The experiment was conducted to study effects of inulin on the growth performance, indices of immune organs and serum immunoglobulin of laying chicklings as well as the performance of inulin which replaced the antibiotics in diets by adding 0.2%, 0.4% and 0.8% of inulin, respectively.

试验旨在通过在蛋用雏鸡日粮中添加0.2%、0.4%和0.8%的菊粉，研究菊粉对蛋雏鸡生长性能、免疫器官指数和血清免疫球蛋白的影响，以及菊粉替代抗生素对蛋雏鸡的应用效果。