级数的和

The product rule and chain rule, the notion of higher derivatives, Taylor series, and analytical were introduced by Isaac Newton in an idiosyncratic notation which he used to solve problems of mathematical physics .

该产品的规则和链的规则，概念，更高的衍生物，泰勒级数，并分析介绍了牛顿的特殊符号，他用来解决问题的数学物理。在他的出版物，牛顿改写他的想法，以适应数学习语的时间，取代的计算几何无穷小的等价论点被认为是无可指责的。

After a power spectrum is constructed, empirical wavelet coefficients are used to detect the jump points in the function to obtain the strong consistent estimator of the position and number of the frequencies. Numerical simulations show this method is reliable.

根据它们的协方差函数可以表示为一个Fourier级数，而其Fourier系数可通过协方差函数的逆变换得到的特性，我们对于零均值的近周期相关序列构造了类似于周期图的函数，并构造其经验小波系数，利用频率处于此函数的尖点的特性，以及此性质在经验小波系数中的反映，来确定频率的个数和位置，所有的估计量都是强相合的，此外，数值模拟的结果表明，我们的方法是有效的。

Since the multiple scattering should be considered, the scattering problem of many-cylinders is more complicated than single cylinder. By using scattering matrix method to solve the scattering problem of many-cylinders, first we have to express the incident fieldand scattered field by special function（for example, Bessel function and Hankel function）under cylindrical coordinate, then use the addition theorem of special function to get a linear system of equations to relate the incident field coefficients and scattered field coefficients. The incident and scattered field coefficients for every cylinder can be solved from the linear equations by matching electromagnetic boundary condition pointwisely.

单颗圆柱散射体的散射场解析解很早就被解出，而多个圆柱阵列的散射场问题因为涉及到入射光在圆柱与圆柱间的多重散射，故散射行为较单颗圆柱的散射复杂，因此圆柱阵列的多重散射问题需要利用加法定理来处理；散射矩阵法的主要精神即是先用圆柱座标下的特殊函数对平面波和圆柱散射体的内外域电磁场做无穷级数展开，再藉由特殊函数的加法定理将所有圆柱散射体的展开中心移到同一个展开中心，最后可以得到一组连结整个散射系统的入射电磁场系数及散射电磁场系数的线性方程组，将该组线性方程配合电磁场在散射体边界的连续条件，便可分别求出圆柱阵列中各个圆柱体的内部电磁场与外部散射场，再利用线性叠加原理即可求得整个圆柱系统的全域电磁场分布。

Secondly, method of Taylor series is used to approximate the slow manifold and the O approximation of the slow manifold is given; slow dynamics such as saddle node bifurcation which has been proven to be the same as that for the full system is analyzed; at the same time, fast dynamics including bifurcation conditions and domain of attractor of the stable equilibrium are also analyzed; the attracting region which consists of the stable manifold of the unstable equilibrium and stable equilibrium is given; we found that when the inner flux decay increases, the domain of attractor is enlarged.

首先，给出了电力系统SMIB模型的时间尺度分解，得到标准的奇异摄动模型；其次，利用幂级数方法，给出了慢流形的O近似M〓，分析了在慢流形M〓上的慢动态，得到了慢子系统的鞍结分支值，并证明此分支值与原系统的鞍结分支值相同；分析了快子系统的平衡点和全局分支的存在条件，给出由不稳定平衡点的稳定流形与稳定平衡点形成的吸引域；并研究内部电压对稳定域的影响，发现稳定域随内部电压增加而扩大；最后给出整个系统的稳定平衡点的近似吸引域。

So, in this paper, a circular cavity witha large radius is used to replace the straight boundary of thehalf space, then the half space problem can be changed tothe scattering problem of two circular cavities to the steadyincident P-wave . Having the aid of the mature cylinderfunction theory, the general solutions of the wave functionscan be given, and an infinite linear algebraic equations ofthe unknown coefficients in the wave functions can be gottenwith the boundary conditions and the Fourier complex seriesexpansion technology, the infinite linear algebraic equationscan be approximately solved by the finite trunction withsatisfying some definite precision, at the basis of thissolution of the equation, the variations and the lay-outs ofthe DSCF at the circular cavity boundary vs. the differentincident angles, the different embedded depths of thecircular cavity as well as the different dimensionless wavenumber of the incident P-wave.

为此，本文采用一个半径很大的圆孔来代替半空间的直边界，将该半空间问题转化为一无限大空间中两个圆孔对稳态P波的共同散射问题，借助于成熟的柱函数理论，通过写出问题波函数的一般形式解，利用问题的边界条件，并采用复数傅立叶级数展开技术将其化为一个仅包含问题波函数中未知系数的一无穷线性代数方程组，在满足一定计算精度的前提下，通过有限项截断进行近似求解，进而讨论了圆孔边界处的动应力集中系数随不同入射角、不同的圆孔掩埋深度、入射波的不同无量纲波数以及介质的泊松比变化和分布情况。

This design according to distributing the rational principle this time, adopt the way of testing many times, design Model YZ18 vibration road roller transmission progression of gearbox, assign every gear wheel of teeth count rationally, calculate every gear wheel and design the necessary parameter, and adopt the way of calculating according to the job requirements, design transmission gear wheel, axle and bearing at all levels of this gearbox ,etc., carry on the intensity to check to some important spare parts at the same time, so as to ensure the practicability originally designed.

本次设计根据分配合理的原则，采用多次试验的方法，设计了YZ18型振动压路机变速箱的传动级数，合理分配各齿轮的齿数，计算出了各齿轮设计所需的参数，并根据工作要求采用计算的方法，设计出了该变速箱的各级传动齿轮、轴和轴承等，同时对某些重要零部件进行了强度校核，以确保本设计的实用性。

Finally, the wave equation of the electromagnetic field of this kind damper isderived from the Maxwells equation. The magnetic flux density at the boundary isassumed to be harmonic, so the analytical result of the wave equation is solved. When therotor rotates, eddy currents flowing inside the conducting material field are caused. Thetangential force acting on the rotor because of the action between eddy currents andmagnetic field is produced. The tangential force causes a retardation torque, which leadsto the increase of power and heating effects.

最后，应用Ahrens的电磁轴承简化模型，从Maxwell方程出发推导了应用于本文所述的被动式电磁阻尼器的波动方程，并用傅立叶级数把矩形磁场展开的谐变磁场作为磁场的边界条件，通过求解波动方程得到磁场的解析解，从而计算了阻尼器对转子的电磁力和由涡流引起的切向力产生的阻尼器附加功耗。

I'm gonna go pack my regular, long bathing suit.

我要去打包我那不起眼的超长泳裤

Random number generators are used in many areas, with the improvement of the computational ability of the computer.

随着计算机计算能力的不断提高，随机数发生器在许多领域有了更加广泛的应用。