二次函数

The growth dynamics of leaf length on stem and tiller could be described with a logistic model, leaf width with conic equation, and leaf shape with exponential function and quadratic equation. The effects of nitrogen and water conditions on leaf growth were quantified by the effective values of leaf nitrogen concentration and water content.

模型采用Logistic方程描述了水稻主茎及分蘖叶片随生长度日的动态伸长过程；利用二次曲线描述了叶宽随GDD的动态变化过程；分别用幂函数和一元二次方程描述了叶形的动态变化过程；另外，以叶片氮素和水分因子分别描述了不同水氮水平对叶片形态建成过程的定量影响。

Then using Positive definite quadratic theory to prove a sufficient condition of Multivariate function's extreme value problem and show some examples about it.

而后利用正定二次型理论，证明了多元函数条件极值的一个充分条件，并给出了其应用的例子。

With the theory of quadratic form, this essay gives out another way to solve the extremum problems of multi-variable functions.

文章以二次型理论为依据，提出了解决多元函数极值问题的另一种方法。

In view of trust region algorithm has good global convergence for solving non-linear quadratic programming problem,the effective elastic module s damage factor and the damage distribution function is introduced by FEM updating .

鉴于信赖域算法在求解非线性二次规划问题中具有良好的全局收敛特性，同时结合有限元模型修正技术，引入有效弹性模量损伤因子和损伤分布函数的概念，在Matlab编程环境下调用ANSYS有限元程序中的APDL语言进行桥梁空间结构的有限元建模，利用信赖域算法调整局部单元的参数，通过连续损伤分布插值多项式拟合连续区段各单元的损伤分布曲线，进而实现了对连续梁桥的动力损伤识别。

The functional by variational calculus leads to a set of elliptic partial differential equations,in particular,Poisson equations,which is possibly solved by numerical methods.

利用变分法可以从这个二次误差指标函数导出一组椭圆形偏微分方程泊松方程，这类方程有相当成熟的数值解法。

In this course we shall develop theoretical methods suitable for the description of the many-body phenomena, such as Hamiltonian second-quantized operator formalism, Greens functions, path integral, functional integral, and the quantum kinetic equation.

在本课程中，我们将会建立一种适合描述多体问题的理论方法，诸如哈密顿二次量子化算子形式、格林函数、路径积分、泛函积分和量子动力方程等。

Now the triangular mesh model simplification algorithm based on edge collapse is very complex.Combining Garland's quadric error metrics algorithm and Hoppe's progressive mesh algorithm,a new algorithm for triangular mesh dynamic model simplification based on cost function is proposed in this paper.

目前基于边折叠的三角网格模型简化算法边折叠计算复杂，没有有效进行动态简化，结合Garland的二次误差度量算法和Hoppe的累进网格算法，提出了基于代价函数的三角网格模型动态简化算法。

The 3 order Yeoh constitutive model is used to describe the mechanical behavior of carbon-filled rubbers, the aging deterioration rule of carbon-filled rubber is discussed by thermal aging test, and an incomplete quadratic polynomial model is established by Response Surface method, which can describe the variation of performance with aging time and temperature of aged rubber.

用响应函数法建立了橡胶性能随老化时间、温度变化的二次不完全多项式模型，定量描述了材料热老化性能的变质规律。

In the modelling of frequency domain, a method to solve quadratic transfer function in non-Gaussian input is studied.

在频域建模中，研究了非高斯输入信号下系统二次传递函数的求解方法。

The integral calculus of Bernhard Riema of the function .

2齐次 函数的二重积分。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。