查询词典 delta function

The D'Alembert formulation is used to avoid the problems of the Dirac delta function.

原因在於波动方程式的基本解总是存在著脉冲函数。

Based on the BISQ model, we studied the elastic wave speed in two-phase porous isotropic media and its relation with Biot-flow and squirt-flow. The Green function is obtained for a point load in the two-phase porous isotropic media using the decomposition of the field potencial and the properties of Delta function. The expression and effects of squirt-flow in BISQ-Green function are discussed.

以BISQ模型的波传播方程为基础，研究了弹性波在孔隙各向同性介质中的传播速度及与流体的Biot流动和喷射流动力学机制的关系，进一步利用场势分解和δ函数的性质，给出了同时受Biot流动和喷射流动两种动力学机制作用下，两相介质波场位移在集中力作用下的Green函数，并讨论了喷射流动在Green函数中的表现形式和作用。

In calculation, the delta function is chosen as the basis and perfect convergence to the FMM results is achieved.

在计算中，选用δ函数作基函数，达到相当好的收敛性。

Delta function is a deliberately defined mathematical tool for analysis, which is devoted particularly to illustrating of the physical model of points distribution, and which is widely applied to analyze the high concentration of quality and energy on one point in space or in time in physics.

δ函数是人为定义出来的一种分析工具，正因为它在数学上的简单性，才导致了它在物理上被广泛应用于研究质量、能量在空间或时间上高度集中的各种物理现象。

By solving the Schrodinger equation and using the boundary conditions of delta function, We can get the Buttiker scattering Matrix.

通过解薛定谔方程求得自旋空间的波函数，再由边界条件确定波函数的振幅，进而求出散射矩阵。

A new approximation function based on the coupling of radial basis functions and polynomial basis functions is obtained, which has the property of Delta function.

径向基函数和多项式基函数耦合可以构造具有插值特性的近似函数。

The system point spread function is designed to be similar to the Dirac delta function. The experimental results and the theoretical calculation of the PSF are in accordance. The experiments on absorbers embedded in the intralipid solution with concentration of 1% and depth of 1.7 cm are implemented.

用菲涅耳波带板扫描全息成像系统进行了成像实验，得到了嵌埋在浓度为1%、深度为1.7 cm的脂肪乳剂中的吸收体清晰的再现像，吸收体为直径0.4 mm的金属丝和内径为6.0 mm的金属环，另外，也得到了直径为2.5 mm的黑塑料球的再现像。

In modeling heavy tails,we focus on multivariate t distributions and derive the moment generating function of the quadratic approximation.Then we use Fourier transform,Chebychev's Inequality and numerical technique inversion to approximate VaR value of portfolio,compared with Cornish-Fisher Expansions normal model and Delta-Normal model.

在推导出多个外汇期权的投资组合的二次近拟的矩母函数表达式基础上，本文使用傅里叶变换、切比雪夫不等式、数值转换计算求出投资组合的VaR的值，并和基于多元正态分布Cornish-Fisher模型以及基于Delta-正态模型计算所得的VaR值了进行比较。

Firstly, based on the generalized function,φ-mapping topological current are rigorously proved to be of delta-function form δ and can be labelled by the nodal indices of the vector field, namely by Hopf indices and Brouwer degrees of this vector field, which reveals the inner relationships between our theory and the topology of vector bundle.

论文首先以广函数为基础严格证明了，φ-映射拓扑流具有δ函数形式，并且可以向量场的零点指标表征，即以其Hopf数和Brouwer度拓扑量子化，从而揭示了它与向量丛的拓扑学之间的内在联系。

Firstly,based on the generalized function,φ-mapping topological currentare rigorously proved to be of delta-function formδand can be labelledby the nodal indices of the vector field,namely by Hopf indices and Brouwerdegrees of this vector field,which reveals the inner relationships between ourtheory and the topology of vector bundle.A singular divergence theorem isalso presented.

论文首先以广函数为基础严格证明了，φ-映射拓扑流具有δ函数形式，并且可以向量场的零点指标表征，即以其Hopf数和Brouwer度拓扑量子化，从而揭示了它与向量丛的拓扑学之间的内在联系。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。