查询词典 Bragg

Fiber Bragg Grating sensors can work in the area of strong electromagnetic field, high temperature, corruptive and explosive bad conditions, therefore have more applications than other sensors.

光纤光栅传感器可以工作在强电磁场、高温有腐蚀性的以及有爆炸危险性的恶劣环境中，因而比其它传感器有更广阔的应用范围。

FBG sensing technology and its recent progress in applications isintroduced systematically;the coupled-mode theory and the sensing principleof FBG are expatiated and the Bragg formula and reflectivity formula arededuced;the work principle, variety and essential characteristic of PZT areexpatiated in detail, and the configuration of PZT parts of an apparatus issummarized. The mechanism of piezoelectric electrostriction is analyzeddeeply, and the normalized control model is introduced aiming at analyzinghysteresis characteristic, and an electrical polarization intensity control methodbased on the aforementioned model which can effectively reduce the hysteresischaracteristic is discussed.

论文系统地介绍了光纤光栅传感技术及其应用的研究进展状况；详细地阐述了光纤光栅的耦合模理论及光纤布喇格光栅的传感机理；推导出了光纤布喇格光栅的布喇格公式和反射率公式；详细地阐述了压电陶瓷的工作原理、种类和基本特性，总结了压电陶瓷器件的结构形式，深入地分析研究了压电陶瓷逆压电效应及电致伸缩机理，并针对其迟滞特性给出了压电陶瓷归一化控制模型，在此模型基础上采用电极化强度控制方法有效地降低了压电陶瓷的迟滞特性。

This paper details the properties and characteristics of the β-eucryptite glass-ceramics with negative CTE (Coefficient of Thermal Expansion) that have been developed to bond to substrates for compensating the thermal variations in fiber Bragg gratings.

本论文以研发能够应用于光纤布拉格光栅温度补偿的材料为目的，开展了负膨胀β-锂霞石微晶玻璃的制备与表征。

When fiber Bragg grating is pressed by local transverse force, the reflection spectra are independent of the applied length. The wavelength of split point is periodical and linearly proportinal to the applied force. And the reflectivity of split point is approximately hyperbolically tangential versus the applied position.

研究表明，当FBG局部横向受力时，受压长度对反射光谱无影响，反射光谱分裂点的波长与横向作用力呈线性正比关系并具有周期性，分裂点反射率与受力位置的关系为近似双曲正切关系。

Mr. Raymond J. Bragg said proudly,"the excellent hotel comes from the excellent employees, but not the beautiful crystal pendant lamp. The international brand background and advanced management experiences are the belongings of Shangri-La. The most praiseful thing is the company culture crammed with the human culture and this is what a best host should possess."

饭店总经理雷蒙杰先生自豪地表示，&卓越的酒店源自卓越的员工，而非绚丽的水晶吊灯或昂贵的地毯，香格里拉饭店具有国际化的品牌背景和先进管理经验，最值得称道的还是香格里拉充满人文关怀的企业文化，这是成为最佳顾主所必须具备的。&

The properties of grating formation are studied specifically when the writing light beam incidents normally and slantingly, respectively.

分析了Bragg光栅的二阶温度、应变灵敏度和温度-应变交叉灵敏度对测摘要一量结果的影响。

He's been arrested for drunken driving, had hundreds of thousands of dollars stolen from him, and his granddaughter Bragg died of a drug overdose, just months after Tribble's death which triggered another lawsuit against Whittaker.

经过几轮的叫牌，赌注金额会越积越多，最后的赢家将获得所有的赌资。

A single-longitudinal mode fiber laser with fiber saturable absorber is designed. Tunable fiber Bragg grating as the wavelength selector is in the ring cavity with a 2 m-long unpumped erbium-doped fiber.

设计了一种基于光纤饱和吸收效应的环形单纵模光纤激光器结构，以可调谐光纤布拉格光栅作为波长选择器件，与2 m未抽运掺铒光纤一起位于环形腔反射臂上。

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 function of 3dB fiber loop mirror in fine wavelength partition is studied. With this theory, a novel narrow linear band, dual-wavelength switchable Er-doped fiber laser is realized.2. An unpumped Er-doped fiber and broadband fiber Bragg grating with high reflectivity is served as an auto-tracking filter, where the space hole-burning effect appears when the laser signal travels and forms standing wave, thus the generation of multi-longitudinal-mode is suppressed. Then the high birefringence fiber loop mirror is introduced to act as comb-liked wavelength filter.

主要包括：1、发现3dB光纤环镜的精细波长分割作用，并利用这种分割机制，研制成功一种窄线宽、双波长可转换的掺铒光纤激光器。2、利用未受泵浦的掺铒光纤以及宽带高反射率的光纤布喇格光栅做自动跟踪滤波器，当穿行其中的激光信号构成驻波时，出现了空间烧孔效应，从而抑制了多纵模的产生，引入高双折射光纤环镜做梳状波长滤波器。

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。