查询词典 bessel integral

While calculating tensor Green's functions, the algorithm of secondary division is adopted to solve the singular problem. The Gaussian quadrature and continued fraction is adopted to calculate the integral with Bessel function. This method not only can ensure the right calculation of tensor Green's functions but also can get high precision.

求取张量格林函数积分时，采用二次剖分算法解决计算中奇异值问题，对于含有贝塞尔函数的积分项，利用结合连分式展开的高斯求积代替常规的快速汉克尔变换方法，确保了张量格林函数的正确计算并提高了计算精度。

Propagation properties of high-order Bessel-Gaussian beam through a misaligned first-order ABCD system have been studied by using the generalized Huygens-Fresnel diffraction integral and augmented matrix .

使用广义惠更斯-菲涅耳衍射积分和增广矩阵，研究了Bessel-Gaussian光束通过失调一阶ABCD系统的传输特性。

Description of bottle beam and reconstruction of Bessel beam based on diffraction integral theory .

衍射理论对局域空心光束及无衍射光束重建的描述。

The boundary element simulation method for the interaction of oblique linear waves with long prismatic floating ocean structures with arbitrary cross section is investigated by using the second kind modified Bessel function. The singular integral method in a constant or linear element and the open boundary treatment are proposed.

采用第二类变形Bessel函数对斜向线性入射波与任意截面形状的长棱柱型浮式海洋结构物的相互作用问题进行了边界元法模拟，给出了常数元和线性元的奇异积分处理方法以及开边界的处理方式。

On the base of Lord Kelvin point-source solution, the integral of Bessel function, Poisson superimpose formula and boundary element method, we resolve it and obtain the boundary element basic solution.

受求解方法局限性的限制，目前经典渗流力学理论还无法精确求解复杂外边界油藏中生产井层部分射孔问题。

The paper simply introduced the basic principle of surface nuclear magnetic resonance and computed the numerical integral of nuclear magnetic resonance kernel function which contained double Bessel functions using the method of Gauss quadrature and continued fraction expansion, and then discussed influence of conductivity to nuclear magnetic resonance′s signal.

简要介绍了地面核磁共振找水的正演理论方法，采用高斯求积并结合连分式展开的方法对核磁共振核函数中包含双重贝塞尔函数的积分核进行了数值积分，进而计算出精度较高的核函数值，在此基础之上，讨论了导电性对地面核磁共振信号的影响。

First, the physical models associated with dislocations and cracks are respectively converted to mixed boundary value problems in mathematics. Secondly, by using the Fourier transform, a dual integral equation for a crack and an algebraic equation for a dislocation can be derived from the boundary conditions relating with a crack and a dislocation, respectively. Solving these equations, exact analytical solutions can be obtained in terms of Bessel functions in close-form.

先把位错和裂纹的物理模型写成与它们相关的边值问题，然后，利用Fourier变换将这些边值问题化成一个对偶积分方程(对位错而言，得到一个代数方程)，求解此对偶积分方程，可以获得以Bessel函数给出的封闭形式的分析解。

Hankel inversion is calculated by Gauss integration in integral region, which are plotted at the zero points of Bessel function.

Hankel逆变换依据Bessel函数零点划分积分段，采用高斯积分计算。

In this paper, the propagation and focus properties for several modes describing hollow beam are analyzed, and the focus properties for hollow gaussian mode are particularly discussed. Furthermore, a new mode, high-order Bessel-Gauss mode, is put forward to describe hollow beams. The results for high order Bessel-Gauss beams propagating through lens focusing system and free space are derived by terms of Collins integral formula.

本文分析了几种描述空心光束数学模型的传输特性和聚焦特性，着重讨论了描述非中空光束的数学模型的聚焦特性；同时提出了一种描述完全中空的空心光束的新模型――高阶贝赛耳高斯模型，并且运用Collins积分公式，分析了这种新模型的空心光束的传输特性和聚焦特性。

Finally, making use of integral equalities associated with Bessel functions, the explicit expressions for elastic displacement and stress fields induced by these defects can be obtained in terms of elementary functions.

最后，通过一些Bessel函数的积分恒等式，便可给出在这些准晶中由这些缺陷所诱导出的以初等函数的明显表达式表示的弹性位移场和应力场。

No clear conclusions can be made about the predictie alidity of specific measures, they found, except for criteria for the underuse of drugs for cardioascular disease.

除了心血管病不合理用药标准外，对于特定评价方法的预测效度没有明确的结论。

The third and last is that almost all of them, being infinite in number, have been impostures, and by idle and crafty brains merely contrived and feigned after the event past.

第三、即最后一点是：几乎所有这些不胜枚举的预言都是欺人之谈，都是在事件过后由无聊而狡猾的脑筋推测与凭空捏造的。