Taking the mean - field model of a nonlinear resonator filled with two - level atomic medium as an example , we use spatial fourier filter techniques to select optical pattern , and first introduce the discrete random filter method which proved to be flexible and effective for the system having rotary invariability 首次提出了离散随机滤波方法，得到了丰富的斑图结构，证明此法可以灵活有效地对斑图进行选择和控制。通过对注入泵浦光调制也实现了对这一系统斑图的选择。
But it has limitations such as inconsistency between strength and theological properties , the problem of volume invariability and the properties of resistance of sulfate erosion especially for concrete in excess of 70mpa . it is an difficulty for both the concrete industry and building industry to ensure the concrete in excess of 70mpa with good theological behavior , ease of transport , volume soundness and durability after hardened 高强混凝土在促进整个建筑业的进步方面功不可没,但是随着应用的混凝土等级的提高,特别是对于70mpa以上的混凝土已暴露出自身的一些缺陷,如混凝土强度与流变性能之间的矛盾,体积稳定性问题,抗硫酸盐类侵蚀性能力的下降等。要使70mpa以上的混凝土具有良好的流变性能,能轻易地泵送,并在硬化后有良好的体积稳定性和耐久性,是国内外混凝土和建筑施工业面临的一项技术难题。
The third party system is a very important system in the administrative litigation law . it is very significant for clarifying the facts of some cases , ensuring fair judgments , avoiding conflicting judgments , safeguarding the invariability of the law , saving judicatory resources , realizing litigation economy 第三人制度是行政诉讼法上的一项重要制度,它对于澄清案件真相、确保裁判公正,避免矛盾裁判、维护法的安定性,节约司法资源、实现诉讼经济具有十分重大的意义。
Two big changes have taken place in the united states " international trade field since 1980 ' s . one of above big changes took place in the field of economic theory . the traditional theory of international trade , which is based on perfect competition and invariability of scale return , can no longer justify many economic novelties 本文以美国20世纪80年代开始实施的战略性出口贸易政策为研究对象,从对战略性出口贸易政策理论的分析入手,对其理论的两个层次,即“利润转移”理论和“外部经济”理论给予阐述和说明,并给予模型和数量方面的分析。
Secondly , basing on the theory of on - off gain of small signal , the raman gain coefficient for frequency shift between 0 . 5 and 20 thz of standard sigle mode optical fiber is measured by pump - probe method through a super luminescent diode ( sld ) as a broadband small signal probe source . thirdly , numerical simulation analysis of gain characteristic of raman fiber amplifier for c band wdm signal light is made according to the raman gain coefficient of the fiber measured before through target and four rank runge - kutta method . at the invariability of wavelength and maximum power of each of two pumps , schematic of powers of two pumps for best flatness on c band wdm optical gain was found out , at the same time , the factors of resulting in gain saturation is analyzed , too 本文首先应用经典的电磁理论对拉曼光纤放大器的工作机制进行了分析，然后，根据小信号理论推导出的开关增益求出了光纤拉曼增益系数的表达式，采用泵浦-探测波的方法，利用超辐射激光二极管( superluminescentdiode简称sld )作为探测光源，测量了所用标准单模光纤频移为0 . 5 - 20thz的拉曼增益系数，之后根据所测得的光纤的拉曼增益系数谱对应用该类光纤构成的放大c波段wdm光信号的拉曼光纤放大器的增益特性采用打靶法和四阶龙格- - -库塔进行了数值计算，在给定了两个泵浦光源的波长和最大功率后，找出了反向泵浦情况下使c波段wdm光源增益最平坦的两个泵浦的各自最佳功率，同时也分析了导致信号光饱和的原因。
Abstract : on the basis of two elementary postulates of the theory of relativity and inferring process of lorentz transformation on time and space , the present paper deals with the general phase invariability of electromagnetic waves , which clearly reveals the inner link between the phase invariability of electromagnetic waves and elecmentary postulates of the theory of relativity as well as lorentz transformation on time and space 文摘:根据相对论的两条基本原理和时空洛仑兹变换的推导思路，论证了普遍的电磁波相位不变性.清楚地揭示出电磁波的相位不变性和相对论的基本原理及时空洛仑兹变换的内在联系
Due to the uniqueness and invariability of fingerprints , the automated fingerprint identification is becoming an attractive alternative to the traditional identification methods . these years , afis is applied more and more aspects in our daily life with the development of computer technology , the appearance of cheap fingerprint sensors and effective algorithms 近年来,计算机技术的飞速发展、低价位指纹采集仪的出现以及高可靠算法的实现,更使得自动指纹识别技术越来越多的进入到人们的生活和工作中,自动指纹识别系统的研究和开发正在成为国内外学术界和商业界的热点。
