查询词典 fredholm alternative

To obtain the unknown intermediate vector function needs to solve a Fredholm integral equation of the first kind, the solution of which can only be determined with a difference of a vector proportional to the normal of the boundary and its integration on the boundary must zero.

可是要求出该积分表达式中待定的边界上的向量密度函数要导致求解第一类Fredholm 积分方程。

According to the space domain iteration method of the Fredholm integral equation of the first kind, the wave number domain iteration formula is deduced for calculating the wave spectrum of the potential field on a lower horizontal plane.

根据第一类Fredholm积分方程的空间域迭代解法，推导出计算向下延拓水平面上位场波谱的波数域迭代公式。

By use of the method of integral equation, the second kind Fredholm's integral equation was deduced to solve the interaction factors of pile-pile, pile-soil and soil-soil. Using the principle of superposition, the piled raft foundation was calculated. The validity of the proposed method was verified through comparison with solutions obtained using other methods by existing theories of elasticity.

采用积分方程法推导出求解桩－桩、桩－土和土－土间相互作用系数所需要的第二类Fredholm积分方程，利用叠加原理对桩筏基础进行计算分析，通过与常规弹性理论方法计算结果的比较验证了本文方法的正确性。

Based on the Biot s two-phase theory for fluid-saturated porous media, considering the inertia force of the solid and the liquid, and the coupling function between the solid and the liquid, and the compressibility of the liquid in allusion to the character of the nearly saturated soils. The dynamic governing differential equations are solved by Hankel transform. Then, considering the boundary condition, the dual integral equations of vertical vibration are established which are reduced to Fredholm integral equation of the second kind.

本文基于Biot两相介质动力固结理论，针对准饱和土地基的特点，考虑了流体的可压缩性，土体和流体的惯性及水土之间的耦合作用，运用Hankel变换技术求解动力控制方程，然后按混合边值条件建立起对偶积分方程，并将其化为易于数值计算的第二类Fredholm积分方程，分别研究了准饱和土半空间地基、上覆单相弹性层的准饱和土地基和准饱和粘弹性地基上刚性基础的竖向振动特性。

Finally, based on the fundamental solutions of Biots consolidation of transversely isotropic saturated multi-layered soils, the Fredholm integral equation of second kind for the interaction between transversely isotropic saturated multi-layered soils and rectangular piles is established, the relevant numerical analysis is also carried out.

最后，基于横观各向同性层状饱和地基Biot固结问题的基本解答，建立了横观各向同性层状饱和地基与方形单桩、群桩共同作用问题的第二类Fredholm积分方程，并进行了数值分析与计算；通过将矩形刚性基础基底划分成若干个大小相等的矩形网格，用矩形均布荷载表示网格的基底反力，并利用已获得的横观各向同性层状饱和地基Biot固结问题的基本解来求解每个矩形网格的柔度系数，然后根据刚性基础与层状饱和地基的接触条件和其本身的静力平衡条件，求解分析了横观各向同性层状饱和地基与刚性矩形板的共同作用问题。

The topics include the spectral theorem, the functional calculus and the Fredholm index.

主题包括谱定理，功能演算和弗雷德霍尔姆指数。

The axially symmetric torsion of rigid circular shaft of varying diameter embedded in an elastic half space is studied by line-loaded integral equation method, where the problem is formulated by distributions of fictitions fundamental loads PRCHS (point ring couple in half space) along the axis of symmetry in interval of the shaft and is reduced to a one-dimensional and non-singular Fredholm integral equation of the first kind and is easily solved numerically.

弹性半空间；本文用线载荷积分方程法研究嵌在弹性半空间的刚性变直径圆轴的轴对称扭转。利用将"半空间的点环力偶"这一虚的基本载荷沿对称轴的圆轴区间中分布就能使本问题归结为一个一维的非奇异的Ferdholm第一种积分方程，且很易用数值求解。文中给出刚性圆锥，圆柱，圆锥柱嵌在弹性半空间的扭转的数值计算的例并和他人的已知结果相比较。

A relative Szego projection is defined in the space of small deformations of 3-d CR structures of finite type, which is Fredholm. We also prove an index theorem, in whose proof we actually have the asymptotic expansion of the Szego kernel.

在三维有限型的CR结构的小形变空间上定义了相对Szego投影算子，并证明了相对Szego投影算子是Fredholm算子和相应的指标定理。

Green quasifunction method is applied to Poisson's equations. Fredholm integral equations of the second kind are obtained. Irregularity of the kernel of integral equations is overcome by choosing a suitable form of the normalized boundary equation.

应用准格林函数方法，可将Poison方程化为第二类Fredholm积分方程，通过边界方程的适当选择，积分方程核的奇异性被克服了。

In the second chapter, modefied Taylor\'s expansion method is studied for solving Fredholm-Volterra integral equations, several illustative examples are given to show the efficiency of the proposed method. More over, by simple algebra, the modified Taylor\'s expansion can also be used to solve integral equations with weakly singular kernel, and the corresponding accuracy is dramatically promoted.

第二章重点讨论了应用Taylor展开方法解Fredholm-Volterra积分方程，通过数值例子，表明了该方法的简单有效性，特别应用于具有弱奇异核积分方程获得了更高精度的解。

The United Kingdom has pledged to provide technical assistance to the peacekeeping effort in Darfur, including airlifting supplies and equipment to assist the African peacekeepers.

英国承诺为达佛的維和努力提供技术帮助，包括提供非洲的維和部队空运补給和裝备。

Results: The level of ET-1mRNA in placental villus was significantly higher in pre-eclamptic women than that in control group.

结果：妊高征组患者胎盘绒毛组织ET-1 mRNA的表达较正常妊娠组明显增高。