微分的

Thismethod adopted affine transformation model and a Lie derivative-based analytical algorithm.We introduced the process and characters in extracting information of biological visionsystem, studied the feasibility of the generalized Gabor function used as receptive fieldfunction in extracting information and analyzed affine transformation group and Liederivatives. Finally, we deduced the mathematical denotation for Lie derivatives, i.e. theinfinitesimal generator of the geometric distortion in affine transformation.

对生物视觉信息提取的过程及特点进行了介绍，其中主要研究了广义Gabor函数作为感受野函数提取初级视觉信息的可行性；对仿射变换作为外界图像信息在视觉成像系统上的投影模型的原理进行了初步讨论；对Lie变换群微分算子用于提取仿射变换不变量的分析方法作了剖析，并推导了该方法中关键部分——仿射变换Lie微分算子的具体表达式，也就是几何变形无限小微分算子的计算表达式，使下一步编程实现该方法成为可能。

At first,the cobweb model in a differential equation's form is established under the condition of continuous time.

首先，在连续时间的条件下，建立了蛛网模型的微分方程形式；其次，通过分析微分方程模型平衡点的稳定性，得到了蛛网模型稳定的条件；最后给出与微分方程模型相应的经济解释和具体应用。

The minimal surface have been extensively employed in many areas such as architecture, material science, aviation, ship manufacture, biology and crystallogeny and so on. In this paper we have some element works on minimal surface from the point view of CAGD It is well-known that there does not exist any other quadratic minimal surface except for the plane.

以肥皂膜问题为物理背景的极小曲面问题或者Plateau问题—寻找以给定空间曲线为边界的面积极小的曲面，从18世纪提出到现在一直是微分几何和偏微分方程理论的重要课题，微分几何领域已经有了极其丰富的极小曲面理论。

Differential equations of tile first order in the finite discrete function are established, the solutions of which have very simpler structure.

引入了有限离散函数的微分与积分新概念，它具有与连续函数微分和积分相类似的性质，由它建立的一阶微分方程的解有较简单的代数结构。

Content: By learning this course, students should grasp the elementary solution of first order differential equation, the structure theory of linear differential equation or system of linear differential equations and the solution of constant coefficient differential equation or system of constant coefficient differential equations.

主要内容：通过对本课程学习，使学生掌握一阶微分方程的初等解法、线性微分方程的结构理论和常系数方程的解法，对微分方程初值问题的一些基础理论有一定的了解，对

In this paper, based on nonlinear stochastic differential equation for phase noise analysis approach is proposed.

文中从描述振荡器的非线性微分方程出发，提出将噪声作为非线性微分方程的一项，通过建立随机非线性微分方程来分析振荡器的相位噪声，为振荡器的相位噪声提出了一种新的分析方法。

This leads to a parabolic partial differential equation for price of bond.

假设利率变化的模型是由随机微分方程给出的，则可以用推倒Black－Scholes方程的方法来推出债券价格满足的偏微分方程，得到一个抛物型的偏微分方程。

Based on the existence condition of the solution for singular ordinary differential systems,the existence condition of the solution of the degenerate neutral differential system as well as the general solution are obtained by defining the solvable matrix pair and fundamental solution and using Laplace transformation.

讨论了对于退化矩阵E不是方阵情形的一般退化中立型微分系统的解，基于退化的常微分系统解的存在性条件，通过定义可解阵对和基础解以及利用拉普拉斯变换，给出了一般退化中立型微分系统解的存在性条件以及通解表达式。

It is found that both the total and differential cross sections increase with the increasing of screening interaction, and especially for energies below 10 keV/u, the cross sections are one to two magnitudes larger than those in the unscreened case.

研究发现，碰撞电离总截面随等离子屏蔽的增加而增大，特别是在10 keV/u以下的低能区电离截面有量级的增加。对随能量变化的一阶微分截面，在低能碰撞过程中，屏蔽作用增加，微分截面呈量级增加，高能碰撞微分截面呈倍数增加。

Scientists' attention is paid to the discription of the self-adjoint boundary condi-tions of singular differential operators during 50 years recently.

对称微分算子理论中自共轭域的描述，是微分算子理论中的基础问题之一，常型的问题在五十年代已得到解决，五十余年来人们更多的注意力放在奇型微分算子自共轭边界条件的描述上。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。