查询词典 equation of variation

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。

Applying energy variation principle, we give equation s defining parameters in flexural function, stability equation , frequency equation , and general formulae of minimum critical force and minimum eigenfrequency as well.

应用能量变分原理，给出了确定挠曲函数中待定参数的方程，以及稳定性方程和频率方程，给出了求最小临界力和最小固有频率的一般公式。

A new conception of power per unit impedance is defined and the basic equation to express the variation of load voltage magnitude with the variation of its dynamic equivalent impedance and that of power per unit impedance is derived.

定义了单位阻抗功率的新概念，推导了电压幅值随其等值阻抗和单位阻抗功率变化而变化的基本方程式。

In this article, with pointing out that the result of the current calculation model is deficient in the similarity, it has deduced the numerical regulation of the variation of the elements including q ,γ andτ in the steam-water distribution matrix equation when the terminal temperature difference exits in the heater via the power balance equation, and combining with the power equation and boiler absorbed heat equation, the precise calculation model for the impact of heater terminal temperature difference on heat economy of unit is then derived.

指出现有计算模型结果具有近似性的不足，本文通过加热器能量平衡方程推导出加热器有端差时汽水分布方程中q 、γ和τ元素数值的变化规律，然后结合功率方程和吸热量方程得到加热器端差对机组热经济性影响的精确计算模型。

Firstly, the three-dimension boundary question and its corresponding variation question concerning the point-source electrical field on a 3-D structure are presented. Secondly, the finite element method is used to solve the variational equation. The study area is divided into many tetrahedral elements. Then, we interpolate with a tri-linear function in each element. So, the variational equation is converted into a linear equation system. Finally, taking into account saving of time, we make use of symmetric successive overrelaxation preconditioned conjugate gradient algorithm to solve large linear system, and obtain the potential value of each node, resulting in the calculation of the apparent resistivity values on the ground surface.

首先给出了三维构造中点源电场的边值问题以及相应的变分问题；然后利用有限单元法求解变分问题，采用四面体单元对研究区域进行剖分，在单元中进行三线性函数插值，将变分方程化为线性代数方程组；最后，考虑到节约计算时间，利用对称超松弛预条件共轭梯度迭代算法求解大型线性方程组，得到了各节点的电位值，进而计算出地表的视电阻率。

The main contents include the ray phenomenon and its generation conditions; the deduction and physical illumination of wave action conservation equation and wave number conservation equation; ray theory for sinusoidal waves; Fermat's principle; the variation of amplitude in the case of straight and parallel depth contours and circular depth contours; the amplitude near the caustics; wave trapping; deduction of mild-slope equation and the relevant numerical solution methods.

讲授折射现象及其发生的条件；波作用守恒方程和波数守恒方程的推导及物理解释；稳恒正弦波的控制方程及射线方程；费马原理；利用射线方程研究等深线是平行直线和圆周线时波振幅的变化，特别是焦散线附近波高的变化以及由此而产生的波的俘获；缓坡方程的推导及有关的数值求解方法。

Second,the variation of artificial earthquake wave in time domain is acquired from the variation of object response spectrum.The above-mentioned equation groups are proved to be non-linear,which can be solved by classical method.

我们将证明上述代数方程组是一非线性方程组，因而方程组的求解和收敛准则可以使用非线性方程组的经典解法。

The degree of water temperature lag during water discharge from the Three-Gorges Reservoir was calculated by use of the thermal equilibrium equation of the reservoir,and the influences of water temperature variation in the reservoir on the procreation of Chinese sturgeons were studied.

分析了三峡库区相关水文站建库前后的水温变化规律，利用水库热量平衡方程计算了三峡水库下泄水温的&滞温&和&滞冷&幅度，并对下泄水温变化对坝下中华鲟繁殖的影响进行了研究。

The inclination of the ecliptic results in the contribution of another sine wave variation with an amplitude of 9.87 minutes and a period of a half year to the equation of time.

黄道倾角的结果导致另一个半年为周期的正弦波变动效应，使均时差在半年的震荡达到9.87分钟。

In this paper, the control factors of anaerobic digestion are discussed based on the summarization of present research literatures. The mechanism of the effect of pH and Eh on anaerobic digestion is analyzed with microbiology and biochemistry theory. The equation describing the effect of pH variation on Gibbs free energy variationΔGis derived using Nernst equation, and the specific control conditions in engineering are summed up according to the present research achievements.

在总结已有文献的基础上，讨论厌氧消化过程的控制因素，并利用微生物学和生物化学理论分析了pH值和Eh对厌氧消化过程影响的机理；利用Nernst方程推导出了描述pH值变化对吉布斯自由能变化ΔG的影响的方程式；并结合已有的研究成果，总结了实际工程中的具体控制条件。

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。