双全

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。

Adopts the all- air and natural ventilation system for the opening north wall;the floating floor and isolation table to isolate machine vibration,the sounds insulation materials between two walls to insulate noises in the plant;the air conditioning system separately for the audience area and sports area,the fan-coil unit and floor heating system only for the sports area to adapt the use after the Olympic Games,the natural ventil...

针对1层两个比赛厅北墙敞开的特点，采用全空气空调系统、排风从敞开空间自然排出方案；针对空调机房距4个比赛厅仅一墙或一板之隔的特点，空调机隔振采用浮筑楼板加减振台板、隔声采用双墙中间夹隔声材料层的方案；针对奥运会后观众区改作他用、运动区继续作集训使用的特点，观众区和运动区各有一套空调系统，运动区另设风机盘管和地板供暖；针对步枪、手枪射击时产生弹药味的特点，采用吊顶设通风格栅、高窗设电动开启的自然通风方案。

The Wheely King is great for the show-and-go crowd - fat chrome wheels hold 5.4 all-terrain Mud Thrasher monster truck tyres, and the Twin Vertical Plate chassis features a super cool chrome-plated tube design that looks just like the real monster trucks you've enjoyed watching!

该wheely国王是伟大的为显示和去人群-发铬车轮举行5 。4全地形泥t hrasher怪物卡车轮胎，双垂直板底盘的特点一个超级酷镀铬管的设计，看起来只是像真正的怪物卡车您所享有的收看！

A Layer 2 LAN switch is operationally similar to a multiport bridge but has a much higher capacity and supports many new features, such as full-duplex operation.

局域网交换机是一种第二层的业务相近，但有更高多端大桥容量并支持了许多新的特点，如全双工操作。

The 458 Italia is equipped with the seven-speed dual-clutch transmission which increases performance whilst providing very smooth shifts even at full throttle.

意大利的458配备了7速双离合器变速箱的性能，同时增加了提供非常平滑的转变，即使在全油门。

Arbitrated loop is a shared, 100 MBps (200 MBps full duplex) architecture.

仲裁环路是一种共享的100 MBps（全双工200 MBps）体系结构。

A wild, wicked slip she was---but she had the bonniest eye, and sweetest smile, and lightest foot in the parish; and, after all, I believe she meant no harm; for when once she made you cry in good earnest, it seldom happened that she would not keep you company and oblige you to be quiet that you might comfort her.

她是个又野又坏的小东西；可是她又有一双动人的眉眼，有最甜蜜的笑容和最轻灵的脚步，在全教区中再找不出第二个能跟她相比的。再说，我相信她的心眼儿到底是不坏的；她一旦把你当真弄得哭出来，她很少不陪你一起哭闹的，让你不得不止住了哭反而去安慰她。

Hydrostatic all-drum travel drive by the hydraulic motors at dual-gears infinitely variable speed. The two drums transmissions are intercrossed for more reasonable weight distribution, realizing higher compaction quality in operation.

行走传动系统：静液压全轮行走由液压高压柱塞马达驱动，二档无级变速；双钢轮采用交叉配置实现驱动，质量分布更为合理，保证了整机在工作过程中达到更高压实质量。

METHODS Acute incomplete ischemia was induced by ligaturing bilateral carotid arterise and cutting heads in mice, the survival time and asthmatic time were observed; the coagulation timewas measured by sheet glass method,and the blood viscosity was also assayed; the platelet aggregation induced by collagen were studied by turbdimetry in vitro.

采用结扎小鼠双侧颈总动脉造成急性不完全性脑缺血模型，观察平均存活时间；另取小鼠断颅后测定断颅喘息时间；采用玻片法，观察胡芦巴总皂苷对凝血时间的影响；采用比浊法；观察其对体外血小板聚集率的影响，并测定全血粘度。

INTERVENTIONS: Cerebral ischemic model was induced by occluding both common carotid arteries for 15 minutes.

干预：双侧颈总动脉夹闭15 min诱发全脑缺血模型，24 h后取脑组织。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。