中心二次曲线

Experimental accuracy and repetition of FBG temperature sensitivity and compensation were discussed.have selected several materials which has bigger coefficient of expansion to do packaging components, have made many temperature experiments, there have not flaws, such as aging, crackle, absciss layer, packaging materials have good temperature sensitivity and compatibility with optical fiber;have designed the simple and practical packaging components, have performed a serials of experiments about accuracy and repetition of FBG wave-length, have obtained the first step conclusion;have analyzed the result and made comparison between the result of different experiment, have summarized the best packaging effect and several rules to reduce mistskes.

本文所做的主要工作包括以下几个内容：一、选取了常见的热膨胀系数大的材料制作封装元件，经过多次一80℃到80℃反复测试，封装元件没有出现老化开裂、封装裂纹、空洞、离层等缺陷，封装材料具有良好的温敏稳定性及复用性，与光纤相容性较好；二、对光纤光栅进行简单、实用的封装处理，就封装效果的优劣性、波长测量的准确度、重复性和封装时产生的波长损失等方面进行了一系列的实验，得出了初步的结论；三、对温敏和温度补偿式封装的实验数据进行了详细的分析和对比，从数字上对温变过程中光纤光栅中心波长的改变及温变曲线进行了定量的分析，在大量实验数据分析结果的基础上，总结出哪种材料封装效果更好，以及如何有效的减小实验误差。

According to the characteristic of the data processing, a interferogram regrouping error correction algorithm is designed, and devise a method to correct the sampling position error of the central dark fringe.

通过对其数据处理流程特点的分析，设计了一种归一化算法，对由干涉图重组时产生的误差进行了校正，并对在数据采集过程中干涉图的中心暗纹位置的采样误差进行了二次曲线拟合校正。

Do some research to find the name of this conic and the how the words vertices, foci, centre and directrix relate to this shape.

做些搜索去找出这个二次曲线的名称以及顶点，焦点，中心点以及准线是怎样与这个图形有关的？

In chapter 3,we dig out two families of invariant quartic curves of a quadratic system.

第五章讨论向量场具有对称中心的二次系统，利用系统的不变双曲线及不变四次曲线，我们确定了一个对应极限环（1.1）分布的二维参数区域，其边界的构成为如下几种常见的极限环分枝：霍夫分析，庞加莱分枝，同宿分枝和异宿分枝。

By analyzing phases velocity profiles and resistance lawv resulted from gas slug in the pipe center,the condition that the secondary flow occurs,phases velocity profiles,formula of drag reduction and a curve of drag reduction have been obtained.

以流体力学基本方程为基础，通过对气体在管道中心形成段塞流的相速度分布和阻力规律分析，得到了二次流发生的条件、各相流体速度分布、减阻率关系式以及减阻率曲线。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。