查询词典 Bessel function

Moreover, the quasi-analytical expressions of the relative concentrations at the mobile region and the immobile region are deduced respectively by using Bessel equation, Bessel function and the method of Laplace transform under the initial concentration zero and the first or second boundary condition of a semi-infinite one-dimensional space.

并分别在初始浓度为零，半无限一维空间内第一类边界条件和第二类边界条件下，利用Bessel方程、Bessel函数和Laplace变换法推导出了可动区和不动区溶质相对浓度的准解析表达式。

The calculating concrete example showed that the difference of results between perturbation method and Bessel function method are relatively.

实例计算证明，摄动法计算的结果与Bessel函数法计算的结果相差较小。

This dissertation has also developed an algorithm for computing Bessel function of high order, which improves the efficiency of the FMM greatly.

同时论文还提出了高阶Bessel函数一个快速算法，这个算法的提出大大提高了FMM的计算效率。论文分析了MEI方法和其它吸收边界条件的思想。

A straight line may be drawn approximately through the innermost maxima of each Bessel function and the origin.

一条直线可以得出大约通过内心极大每个Bessel函数和原产地。

In chapter 1, firstly, by using classical analysis methods, such as the introduction of Bessel function and semigroup theory, we transform the pseudo-parabolic equation into an abstract operator equation and achieve the existence and uniqueness of the local solution.

在第一章中，利用经典的分析方法，引入Bessel势函数，将伪抛物型方程转化为抽象算子方程，首先，利用算子半群理论，论证了局部解的存在唯一性。

According to the Navier-Stokes' equations and using themethod of Bessel function of imaginary argument,a system of foimulas is obxained.

从基本的Navier－Stokes方程出发，进行线性化之后采用虚宗量Bessel函数的方法求解，得出了一组描述血管振荡状态下发展流动的速度分布、压力分布公式。

Within this framework we develop a theoretical approach to interpret photoelectron angular distributions in terms of a generalized phase Bessel function which can determine the principal features of the distribution and its variation with laser frequency and intensity.

文章作者及其合作者发展了光电子角分布的处理方法，利用复合相位Bessel函数来表征光电子的跃迁几率幅，将光电子的角分布与复合相位Bessel函数直接联系起来。

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。

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。

For narrow-band signals, three uniform linear arrays, whose grating lobes are not overlapped by setting the angles between the arrays and the same pointing of main-lobes, are used and then multiplication of three patterns is operated to reduce the grating lobes of large-spaced array, which makes the array operate in broad band. For wideband or ultra-wideband signals, array pattern in the whole frequecy band is identical by designing the frequency-dependent weighting coefficients based on the Bessel function, and therefore grating lobes in high frequency parts are suppressed.

对于窄带接收信号，利用三个相交的大间距均匀线阵，通过设置它们之间的角度和主瓣指向相同使各自的栅瓣位置错开，然后把三个方向图相乘从而抑制大间距阵列栅瓣，因而适用于宽频带工作；对于宽带接收信号，利用Bessel函数设计与频率有关的加权系数，产生整个信号带宽内恒定的方向图，从而抑制了高频部分的栅瓣。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。