元表的键值称为事件；值（换而言之就是函数）称为元方法。
The keys of the metatable are called events; the values (in other words, the functions) are called metamethods.
换而言之，当约束使用新的(x 1,x2)对时，x2的变化不会引起目标函数值的变化。
In other words, a change in x2 won't change the objective function's value, given that the constraint holds for the new (x1, x2) pair.
用特定系数法、换元法、配方法探求二元二次函数的极值公式。
The extremal formula of binary quadratic functions is studied by using method of undetermined coefficients, substitution method and method of completing the square.
如你所愿了，你可以建立一个函数，然后运行一下试试了。换种说法就是，在调用之前一定要先把函数定义好。
As you might expect, you have to create a function before you can run it. In other words, the function definition has to run before the function gets called.
以损失数作为目标函数来表征该热力学过程的不可逆程度，分析了管道内对流换热过程中的损。
The exergy loss number is used in this paper as the objective function to indicate the irreversibility of the thermodynamic process.
研究了空气流动速度、肋片排列方式以及几何尺寸对散热器综合换热性能的影响，并且以最小化F为目标函数优化了散热器。
The influence of air velocity, heat sink configuration and dimension on the heat transfer performance is studied. Minimum F is considered as objective function to optimize the heat sink.
仿真结果表明换极后的球谐函数计算扰动引力能够满足精度要求，且在计算中弹道方程的解算速度也有很大的提高。
The result of simulation indicates that this method not only satisfies the precision but also enables us to enhance the calculation speed of the trajectory equations.
文中运用了一种改进的球谐函数法，即换极法，大大简化了勒让德函数的递推计算，并进行了换极前后被动段扰动引力的仿真计算。
In this paper the improved method, also named transformation of the polar, is used to predigest the iterative calculation, and the simulation calculation has been progressed.
接着对直流无刷电机的基本组成环节、基本工作原理、运行特性和传递函数作了详细的介绍，分析了直流无刷电机的换相过程和PWM信号的分配情况。
Followed, it analyses the course of changing phase and distributing of PWM signal. Based on these facts, we present the sensor solution for BLDC motor, design the hardware system and software system.
通过对实际车辆单元换道轨迹的观测与换道执行时间的统计分析，建立了车辆换道转角与车速的函数关系。
By analyzing the track of vehicle's lane changing and the span of lane changing, we establish the relation between velocity and Angle of lane changing.
通过在积分换元、微分方程求解、多（一）元复合函数求全微分、偏导数及高阶偏导数中的应用举例，论述了一阶微分的形式不变性在微积分学中的作用不应被忽略。
Based on the theory of differential geometry and geodesy, the second order differential equation and the first differential relationship are derived on the regional earth ellipsoid in this paper.
通过在积分换元、微分方程求解、多（一）元复合函数求全微分、偏导数及高阶偏导数中的应用举例，论述了一阶微分的形式不变性在微积分学中的作用不应被忽略。
Based on the theory of differential geometry and geodesy, the second order differential equation and the first differential relationship are derived on the regional earth ellipsoid in this paper.
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