According to the theory of electromagnetic fields , the large salient synchronous generator with fractional stator slot are calculated and analyzed by the finite element method ( fem ) in this paper . the fourier analysis method is applied to decompose the air gap magnetic density into the basic spatial component and a series of harmonic components and wave shape eigen coefficient of air gap magnetic field are calculated 本文根据电磁场理论，从耦合场的弱耦合角度首先计算了定子具有分数槽绕组的大型水轮发电机的电磁场，采用付立叶谐波分析的方法把气隙磁密分解为空间基波和一系列谐波，进而计算出气隙磁场波形特征系数。
When the applied bias voltage is changed within positive slope regions of u - i curve , the domain boundary between the high and low electric field domains does not moved , and the size of electric field domains regions is also not altered , while the electric field strengths are adjusted 用模拟计算的方法研究了弱耦合掺杂gaaa / alas超晶格在时变电压下的场畴机制和固定偏压下电流自维持振荡。在时变电压下，一定掺杂的超晶格处于稳定的电场畴， u - i曲线呈现锯齿状波形。
The electric field domains and current self - oscillations which result from sequential resonant tunneling between different subbands of the superlattice are very significant phenomena . we have optimized the simulation using matlab software . comparing the processing data , we know that various ode commands solve problems with different difficulties 本论文主要内容包括以下几个方面：运用matlab软件进行模拟计算的算法优化，从比较掺杂弱耦合gaas / alas超晶格模拟计算的过程数据可得，不同的ode命令可求解问题的难度是不同的：针对较低难度问题，即研究固定偏压下超晶格纵向输运的求解问题( du / dt = 0 ) ，一般首选ode45 。
Accordingly , using graph theory and operating experience abroad for reference , it firstly brings forward a new method of voltage rectification which based on pilot bus with voltage control area in view of the weak coupling among every vca ( voltage control area ) , using decomposing method of multi critical value , it realizes the eliminating vinculum of every vca . and then , the rectification starts by pilot bus voltage of every vca . so the resolution of whole power net is diverted into calculating smaller sub - net 由于各个电压控制区之间无功电压的弱耦合性，利用多阀值分解的分区算法，实现区域间的解耦，然后根据各个子网络的主导节点的电压进行校正，从而把求解整个网络的问题转化为求解各个小的子网络，降低了网络维数，减少了无功设备控制动作次数，提高了校正成功率，缩短了计算时间。
In the beginning , the development history and the current development of the technique of fiber detection are introduced briefly . then , discussed in detail are strong coupling theory concerning the fbt coupler and the weak coupling theory concerning the hf acid etching and the side - polishing coupler . from the analysis of fiber coupling equations , the solution of the equation and the formula of the coupling coefficient are derived 本文首先概述了光纤窃听技术的发展历程和现状,有针对性地分析了关于光纤窃听技术中的光纤耦合问题,并详细介绍了用于熔融拉锥耦合器的强耦合理论和用于氢氟酸腐蚀与边研磨光纤耦合器的弱耦合理论;分析了耦合模方程,得出了耦合模方程的形式解,推导出耦合系数的计算公式。
Based on the coupled mode theory , the reflect spectrum of ofbg is derived . the influenced of grating length , coupling coefficient and chirp coefficient to the maxium reflectivity and reflection bandwidth of ofbg are discussed in details . we find that under weak couple conditions ( the couple coefficient k < 1 ) , the reflect spectrum of an ofbg approximately has a characteristic of sa2 ( x ) shape , which matched to the power spectrum of an optical communication signal 本文在利用耦合模理论对均匀及线性啁啾变迹光纤光栅( ofbg ： opticalfiberbragggrating )的反射谱进行分析的基础上，发现弱耦合条件下(耦合系数1 ) ，均匀ofbg的反射谱具有类似与sa ~ 2 ( x )函数的分布特性，从而创新提出利用ofbg对光纤通信系统中光放大器的ase噪声进行匹配光滤波的设想。
Since the concept of superlattice was proposed , vertical transport in superlattice has been investigated widely . the electric field domains and current self - oscillations which result from sequential resonant tunneling between different subbands of the superlattice are very significant phenomena . such kind of oscillation can be uesd to make tunable microwave oscillaors . in this thesis , low temperature transport problem , especially the formation of field domain and the condition of current self - oscillations in doped gaas / alas superlattice with weak coupling are investigated thoroughly and also by combining the macroscopic model with the microscopic one . , the voltage - current characteristic and the current oscillation are simulated . the calculated result is nearly consistent with the experimental data 由超晶格中子能级之间的顺序多阱共振隧穿引起的电场畴及电流自维持振荡现象是其中的一个非常有意义的分支，该现象可用来制作电压调谐微波振荡器。本论文对弱耦合掺杂gaaa alas超晶格中的纵向输运特别是针对低温下的场畴的形成和固定偏压下电流自维持振荡产生的条件进行了深入的探讨，并结合宏观模型和微观模型对超晶格在时变电压作用下的电压-电流特性以及固定偏压作用下的电流特性进行了模拟计算。
