Therefore , the three fundamentals required to obtain high precise measurements are : 1 ) frequency stability and frequency difference stability of the double - frequency laser source as well as the stable equivalent length of bore ; 2 ) the measuring beam and the reference beam are placed very co - axially ; 3 ) capability of recording the sub - division of the period of phase change and a reversible counter system 因而干涉仪系统达到高精度的基础是：频率及频差稳定的双频激光源、稳定的等效腔长；测量光与参考光合光后有很高同轴度的光路结构；能可靠记录相位差变化周期数的细分及可逆计数系统三部分。
At the same time , through reviewing the principle of residence design in passing time and the family ' s period change in our country , the thesis will bring up one kind of residence space which can fit the stem family . from the thesis , we hope it can cause everyone ' s consider with the stem family ' s living space , and can lead the residence design of the family rightly 同时，通过回顾和借鉴以往对于套型设计中的设计原则和家庭变化周期，提出一种适合我国现阶段主干家庭的住宅设计，从而希望引起各方面对于这类家庭的重视，以此能有效正确的引导设计市场对主干家庭住宅空间的合理设计。
There is a period of soil contents range from ten to twenty five days over the humid discussed area in summer , and the period is not obvious at the discussed zone of close oasis desert area in summer and winter . ( 2 ) soil temperature exits several periodic variations of different depths ranging from six to twenty four days in heihe region , and nine to thirty days in gaize and shiquanhe region . it also shows that gradient of soil temperature affects on the soil content movement more greatly in summer . ( 3 ) the land surface temperature of yangtze river lower region is retrieved from noaa - ahvrr data ( 2 )根据土壤温湿资料，采用功率谱分析、 pca分析等方法，分析了两种典型下垫面土壤温度的时空分布特征及其对土壤水分运动的影响，发现研究区土壤温度除日和年变化周期外还存在6 30天的不同周期；下垫面的非均匀性及其季节变化及温度梯度变化对土壤水分运动有很大影响，冬季温度梯度变化对土壤含水量影响大于夏季温度梯度对上壤含水量变化的影响，且温度梯度与水分运动方向相反。
It is showed that the heat transport crossing the equator has the similar magnitude and the same period of one year , compared with that of 10 n in arabian sea . by contrast , the heat transport across 10 n in bay of bengal has a much smaller value with a prominent semiannual period ; there are tight relationship between integrated zonal wind stress in one latitude of the indian ocean north of 7 n and the total heat transport across that latitude , as well as the total net surface heat flux north of that latitude . the maximum correlation coefficient is less than - 0 . 5 结果表明越赤道和越10on阿拉伯海的热输送量大小具有可比性，且有相同的年循环特征，而10on孟加拉湾纬度的经向热输送较小，且具有半年变化周期;俨s以北印度洋任一纬度上的纬向风应力异常与此纬度上的经向热输送异常以及此纬度以北印度洋总的海面净热通量异常有很好的相关关系，相关系数最大可达一0 . 5以上。
