查询词典 modified bessel function

Radial basis function coupled with a polynomial basis function was used as a trail function, and a Heaviside function was used as a test function of the weighted residual method.

这种无网格方法采用径向基函数耦合多项式基函数来近似试函数，采用Heaviside函数作为加权残值法中的权函数。

The Frechet derivative of the cost function is determined via the solution of an adjoint partial differential equation, and the boundary shape is then modified in a direction of descent. This process is repeated until an optimum solution is approached. The advantage is that the cost function variation is independent of the flow field variation, with the result that the gradient of cost function with respect to arbitrary number of design variables can be determined without the need for additional flow-field evaluations. So each design cycle requires the numerical solution of both the flow and the adjoint equations leading to a computational cost roughly equal to the cost of two flow solutions.

虽然他们的研究成果大多数都可以在公开性文献上看到，但是其中一些具体的细节问题的处理方法却没有透露，比如：伴随方程如何离散求解才能减小最终梯度计算中的误差，使得设计过程有效地进行；伴随方程与流动方程的边界条件是不同的，如何合理地处理伴随方程的边界条件，才能推动设计过程朝着设计目标而发展；在减阻问题中目标函数如何定义，求解梯度的具体数学公式如何推导，如何通过数值方法来实现它们等。

The membership function can exactly express the fuzzy satisfaction set by considering the vagueness of satisfaction degree of objectives and introducing the membership function for the fuzzy satisfaction sets of system reliability and system cost. The normal distribution and Cauchy distribution of this membership function is modified according to the fuzzy satisfaction sets. By doing this, the multi-objective optimization problem can be converted to a single-objective optimization problem to be solved.

模型充分考虑到目标满意度的模糊性，通过引入系统可靠度与费用的模糊满意集的隶属函数，并根据它们的模糊满意集对其正态分布、柯西分布进行适当修改，使之能够准确表达通常情况下的这两个目标的模糊满意集，最终，把两目标优化问题转化为常规单目标优化问题求解。

In chapter 3,we study the Zakharov-Kuznetsov-Modified Equal-Width equation by employing the extended Jacobi elliptic function expansion method and obtain some new solutions of Jacobi elliptic function type of the ZK-MEW equation.;Secondly,using sn-cn method,we study K(m,n,1) equation and obtained some new exact solutions when k=s=3,especially obtained abundand solitary solutions and trigonometric function solutions when m→0 and m→1;In chapter 4,Painleve singular analysis was applied to nonlinear PDE with variable coefficients.

第四章将Painleve奇性分析方法应用到带阻尼项的变系数Burgers方程中，并得到了该类Burgers方程具有Painleve性质的条件，给出了该类Burgers方程的Backlund变换，用所得Backlund变换得到了若干精确孤立波解，包括奇异孤立波解，这些解不等同于行波型孤立波解；用齐次平衡法得到了对数型DBM方程的Backlund变换，并获得了DBM方程的各种孤立波解，包括尖峰孤立波解和奇异尖峰孤立波解。

Then, on the basis of Atluri's work, a modified MLPG method is employed, in which the moving least squares approximation is used as a trial function and the Heaviside function is used as a test function of the weighted residual method.

然后基于Atluri等人的工作，采用移动最小二乘近似函数构造试函数，采用Heaviside函数作为加权残值法中的权函数，采用直接插值法施加本质边界条件而不采用罚函数法和拉格朗日乘子法。

In order to fit the terrain condition, this dissertation uses Mathieu function and modified Mathieu function during the process of wave function expansion, also tries two different methods in small elliptical hill and high elliptical hill to overcome the barrier of composite boundary condition.

展开时为了克服混合边界条件带来的影响，在扁平椭圆地形和高陡椭圆地形中分别尝试了现有的两种方法并分析了其中存在的题目。

The aim of this study is to develop a composite of the modified MUSCL and modified bounded downwind scheme with a switching function.

本研究主要的目的是在於发展一种在 modified MUSCL 和 modified bounded downwind scheme 之间转换的混合离散法。

This thesis divides prefaces altogether, introduction,research of the diatomaceous earth, carrying calcining dealing with and purly diatomaceous earth, diatomaceous earth application in modified asphalt , diatomaceous earth among modified pitch modify mechanism probe into function to asphalt and conclusion 6 parts .

本论文共分前言、硅藻土的研究、硅藻土的提纯和煅烧处理、硅藻土在改性沥青中的应用、硅藻土对沥青改性作用的机理探讨和结论六个部分。

In order to simulated the characteristics of dynamic regression of saturated sandy soil under cyclic loading, the relation between the real hysteresis loop and the one indicated by the Masing rule is discussed based on a series of laboratory test, the modified proportion coefficient of hysteresis loop simulated by the Masing rule indicating by the stress history is determined, and then, it is modified by a quadratic function.

为了描述周期荷载作用下饱和砂土的动力衰减特性，试验研究了周期荷载条件下不同剪应变幅值时的实际滞回圈与由曼辛法则确定的滞回圈之间的关系，给出了由应变历史表示的用曼辛法则描述的滞回圈的比例修正系数，进而用二次函数进行了修正。

However, for the collision processes in He target, a large discrepacy between the CTMC results and experimental measurement is found. As is well known, the microcanonical distributions of bounded electrons in CTMC method is quite different from quantal distributions, we modified the initial microcanonical distribution by using eleven different ionization thresholds of electron bounded in target. With modification, we calculated the collisional process of O~(3+) with He, and the total cross sections of all processess are calculated as a function of the incident energies. The agreement with experiments is improved by the modified distributions.

但由于靶电子的微正则分布与量子分布有很大不同，在计算离子与He靶碰撞时发现结果与实验差距很大，我们基于使用多个系统总能量U值，对初始电子的微正则分布进行了优化，使其更接近于量子力学的径向空间分布，然后计算了O~(3+)与氦原子随入射离子能量变化的各种反应过程截面，发现优化极大地提高了计算精度，特别是我们的模型对于描述单电子、双电子丢失过程非常成功。

Bob Eckert has been chairman and chief executive of Mattel for eight years.

美泰董事长兼首席执行官鲍勃·埃克尔特在任已8年。

The outlook for honors and disgraces carries on and surpasses the traditional outlook for honors and disgraces theoretically, and carries on and develops the theory of construction of socialist mora...

社会主义荣辱观的提出在理论上是对传统荣辱观的一次继承和超越，是对社会主义道德建设理论的继承和发展，在实践上有利于形成良好的社会风尚。