目标不同

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。

It analysises six constraints which influence the development of production and twelve subfactors velated to six constraints,and,in three hierarchical level,using Analytical Hierarchy process,it calculates these on a DJS-130 computer,obtains weights to the general goal.

首先，根据问题的性质和要达到的总目标，将问题分解成为不同的元素，按元素间的关系，建立层次结构；在每一层次中，按某一准则进行判断和比较，形成判断矩阵，通过计算矩阵的特征值，得出该元素对于准则的权重。

Based on an investigation of a certain waterhead region for pollution of organic chemicals, like oils and benzene, heath risk assessment of drinking water in the region was performed using the MMSOILS model, a multimedia exposure assessment model, with Benzene as a target contaminant.

以某水源地油和苯等有机污染调查为依据，利用多介质暴露评价模型，以苯为评价的目标污染物，分析烯烃厂不同分区的土壤苯污染对A地区造成的饮用地下水健康风险。

This work will help the application of the BIOLOG method and improve understanding of the functions of microorganisms in ecosystems.

通过对不同方法应用目标和原理的分析论述了各自优缺点，对微生物研究中基于BIOLOG方法数据分析的选择应用提供参考。

Entrust main body to set out from what differ, research analysed the premise condition that carriage representative exists, put forward to carry acting enterprise to reduce the direction of management cost and development goal, with period the existence that is carriage representative enterprise and development provide academic basis.

从不同的委托主体出发，研究分析了运输代理存在的前提条件，提出了运输代理企业降低经营管理成本的方向和发展目标，以期为运输代理企业的存在和发展提供理论依据。

Although teachers from different academic backgrounds do not have significant improvements towards teaching goals and activities, they have differences in availing instructional representation.

不同学科背景的教师对教学目标与教学活动的诠释并没有明显的趋向，但在教学表徵的使用上却存有差异性。

For England, Beckham scored in three separate World Cups and captained his country for six years, playing 94 times and scoring 17 international goals.

在英格兰，贝克汉姆分在三个不同的世界杯，并带领他的国家，为6年来，发挥着94倍，取得了17项国际目标。

"Chess:a board game for two players, each beginning with 16 pieces of six kinds that are moved according to individual rules, with the objective of checkmating the opposing king."

国际象棋：一种两人参加的棋盘游戏，每人最初执16枚棋子，其中分为六种，每种按不同规则移动，目标为将死对手的国王。

In the process of writing,on the principle of reasonable,well-documented and well-knowing,the author provides its service goals and tries to further defined its special functions for amplifying the company"s management systems and operating mechanisms. The author also ports out the anything of the operating responsibly of the supreme administer should belong to the external auditing. The pattern of internal auditing should be choused or built on the basis of the actual situation. It can"t copy the actions of the foreign countries me chaniclly. The selective patterns for the different kinds of enterprises are introduced as well.

从国有企业扩大经营规模后内部控制，内部管理现实需要的立场出发，提出企业内部审计内向服务目标，试图明确，内部审计对企业机制健全和企业健康营运维护的特殊作用；特别指出对国有企业最高管理当局经武汉理工大学硕士学位论文营责任的审计应归之于外部审计；企业内部审计模式的选择与建立，不可生搬硬套国外作法，需要根据实际情况或是参考改造，或是摸索新建，并介绍了不同类型可供企业参考。

With our simulator five independent targets and land clutters can be simultaneously real-time simulated.

本模拟器可以同时对五个不同运动轨迹的目标和地杂波进行实时模拟。

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。