定义方程

With the support of a major research grant of Zhejiang Province (No. 001101027) and the Plan of Promoting Education of Excellence of Zhejiang University in the 21st Century, this dissertation is devoted to address the above problems and fabricate an L-band EDFA with low cost, high performance and technological innovation.First the mechanism of an erbium doped fiber amplifier is introduced. Various theoretical models based on classical rate propagation equations are summarized and compared for their applications. We use a modified numerical model based on the Giles model, which agrees with the experimental results well. This serves as the theoretical base for the whole thesis and will be used to optimize the characteristics of EDFAs. A novel method based on a map of noise figure and gain is proposed to analyze efficiently the dependence of the noise figure and gain for EDFAs on the EDF length and the pump power. The characteristics of various EDFAs are studied and compared.Secondly, some important parameters are introduced to describe the characteristics of EDFAs. The methods and the experimental setups for measuring the gain and noise figure of an EDFA are emphasized. We introduce how to measure the characteristics of each component of an EDFA, especially the gain and absorption coefficient of an erbium doped fiber.Thirdly, four types of simple and novel L-band EDFA structures with low noise, high gain and low gain ripple are proposed to satisfy the requirement of a DWDM system. They can be classified into two categories. In the first category, a single ASE pumping is served asa secondary pump. This category includes the following three types. Type: a new construction using a fiber Bragg grating in an unpumped EDF section at the input side. Type: a new structure of L-Band EDFA with two-stage pumps, which utilizes the forward ASE as a second pump.

本论文本着科技创新、服务于生产实践的精神，以设计价格低廉，性能优越、结构合理简单的L-band EDFA为目标，依托浙江省科技厅重大科学基金资助项目(001101027)和浙江大学振兴教育计划资助的全光网络的搭建—《光通信技术》课程实验建设项目，展开了如下工作：首先，介绍了掺铒光纤放大器的工作原理，归纳总结了基于速率方程基础的EDFA的各种理论模型，分析比较了各个模型的特点和适用场合，最终选择完善的Giles理论模型作为本论文分析设计EDFA的理论基础；针对实际实验条件提出了修正的EDFA模型的数值计算方法；创新地提出了增益—噪声系数全局分析法，直观有效地分析了EDFA的增益和噪声系数与掺铒光纤长度和泵浦功率的依赖关系，并对各种EDFA的性能作了全面的比较；第二，介绍了掺铒光纤放大器特性参数的定义与测量方法，重点介绍了噪声系数和增益系数的测量方法及实验装置；介绍了组成掺铒光纤放大器各组件的特性测量方法，重点介绍了测量掺铒光纤参数的方法和实验装置；第三，针对WDM系统对L-band EDFA谱平坦、低噪声、高增益的要求，我们创新地提出了四种不同的L-band EDFA结构，按设计思路可以分为两大类：一类是基于单抽运二级泵浦法，这一类包括在未泵浦掺铒光纤的输入端插入一根布拉格光纤光栅的两段L-band的EDFA的新结构；基于前向ASE光作为二级泵浦源推动下一级EDF工作的泵浦分配、两段级联L-band的EDFA的新结构；基于单根光纤光栅、泵浦分配、两段级联的EDFA；另一类则是基于同时应用前后向C-band ASE作二级泵浦源的双抽运法，如基于前后向ASE光作为二级泵浦源的三段级联L-band的EDFA的新结构。

The solutions give not only pore water pressure, pore air pressure and vertical displacement of subsoil, but also initial settlement and consolidation settlement.

从控制方程同时解出了竖向位移、孔隙水压力和孔隙气压力；不仅给出了固结沉降，还给出了瞬时沉降；定义了能综合反映地基特性的固结系数和固结度。

In this work,the volume data is encapsulated firstly and its logistic coordinate is defined,then the direction vector and the center of the cutting plane are calculated,the movement route of the plane is solved,specially a new sampling rule in cutting plane is presented.

该方法首先对体数据进行封装并定义逻辑坐标系，接着在逻辑坐标系中计算剖切平面的法向量和中心，求出平面的运动轨迹方程，并提出一种新的剖切面采样准则。

Equation (1a) denes the three cost-revenue objective cri- teria to minimize initial capital cost, minimize annual op- erating cost, and maximize annual income revenue (i.e., minimize 1/annual income revenue) for the oce build- ing.

方程（1A）条定义了三个成本，收入目标光绪特里亚减少初始资金成本，减少每年的运算 erating成本，并最大限度地年收入收入（即，收入减少1/annual收入）为办公构建荷兰国际集团。

Ellipsoid is given followed by the same definition of the standard ellipsoid equation, and the long axis of the ellipsoid volume formula of a ternary quadratic equation that the circumstances under which ellipsoid provides the basis to determine the final conditions in the ellipsoid three-ball, how long, the size of it?

接着同样给出椭球面的定义，椭球面的标准方程，及椭球的三轴长，体积公式，对一个三元二次方程什么情况下表示椭球面提供了判断依据，最后在此条件下椭球的三轴长又如何计算，体积呢？

By discussing evolution equations of internal variable defined on the point set of time and Clausius Duhem inequalities, a criterion for judging satisfaction of consistency condition is proved, which provides a foundation to establish unified constitutive relations,both time dependant and independant.

把内变量演化方程定义在时间的点集上，结合讨论ClausiusDuhem不等式，证明了一致性条件成立的判别准则，为建立时间相关—时间无关统一的本构关系打下了基础

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。