查询词典 chemical fiber

This paper presents a temperature testing technique based on fiber-optic transmission and the principle of optical fiber, the coupling between the optical fiber and photoelectrical probe, linear solution of temperature sensitive components.

提出了一种基于光纤传输的温度测试技术，重点介绍了光纤测温原理、光纤耦合和温敏元件的线性处理技术，并分析了表面发射方式的光纤耦合传输特性。

A long period fiber grating is a band rejection fiber device with periodical retractive index modulation formed along the axis of the fiber core.

长周期光纤光栅是在光纤纤芯中沿轴向形成折射率周期性调制的带阻型光纤器件。

Wide angle X-ray diffractometer was used to investigate the formation of crystal structure of Lyocell fiber and the difference of crystal structures between never dried Lyocell fiber and rewet Lyocell fiber.

利用广角X-衍射分析技术，对从未干燥过的初生Lyocell纤维结晶结构的形成过程进行了研究，并与已干燥过的重新湿润的Lyocell纤维的结晶结构进行了对比。

Shoe of limit of use constant letter undertakes the limit erupts training basically is flesh fiber medium fast flesh fiber enlists campaign, sarcous is offerred can means is given priority to with metabolizing without oxygen, after the crus after training group sarcous exterior moves locally, fast flesh fiber adds thick, scale to increase; Muscle systole is more fast and consequently strong.

使用恒信极限鞋进行极限爆发练习主要是肌纤维中的快肌纤维参与运动，肌肉的供能方式以无氧代谢为主，练习后小腿后群肌肉的外观位置上移，快肌纤维增粗、比例增大；因而肌肉收缩更加快速有力。

It is shown that the surface of carbon fiber displays a high propens ity to nucleate PP crystallization. The nuclei density at the surface of carbon fiber is much higher than that in the bulk area, and the resulting radial growth produces a type of transcrystalline structure, and the characteristic temperature of crystallization increases with carbon fiber concentration.

碳纤维表面对聚丙烯结晶过程具有明显的促进作用，纤维表面成核密度轻高，结晶生长成为横穿结晶，结晶特征温度随碳纤维加入而有不同程度的升高。

To meet the needs, a novel low-noise fiber laser with compound cavity structure is designed. The stable single-mode operation is realized by using a transient self-written fiber grating, produced by the effect of saturable absorption within a section of unpumped erbium-doped fiber, as narrow band filter for mode selecting and linewidth squeezing. Through optical path modification, the spectral signal-to-noise ratio is better than 62 dB.

激光器采用复合腔结构，以掺铒光纤作为工作物质，通过在未被抽运的掺铒光纤中形成的瞬态自写入光纤光栅的窄带滤波特性进行选模和压窄线宽，产生稳定的单频激光输出；经过光路改进，激光输出光谱信噪比优于62 dB；利用光电负反馈电路，弛豫振荡峰下降了约25 dB，低频段强度噪声也大为改善，有效地抑制了光源的强度噪声。

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。

To realize single longitudinal-mode of the fiber laser, a ring configuration is devised. The single longitudinal-mode operation is realized by using a fiber Bragg grating as wavelength-selective element and a unpumped 2m-loog erbium-doped fiber which can produce stading-wave saturation effects in the cavity, Its tunable wavelength range is 42 nm, the output power is more than 3.5 dBm and the stability is less than ±0.005 dB.

为了实现光纤激光的单纵模，提出了一种环形腔结构，采用可调谐光纤Bragg光栅作为波长选择器件，与2m未抽运掺Er光纤产生驻波饱和效应，在1.55m波长处形成42nm激光输出，输出功率大于3.5dBm，功率稳定性优于士0.005dB。

Spatial holeburning caused by ununiform widening of erbiumdoped fiber barricades the fully gaincontrolled amplification of laser with single wavelength. A novel configuration of automatic gainclamped optical erbiumdoped fiber amplifier is presented, and a high-birefringence fiber Bragg grating is used to generate pumping lasers, peaks of which are written at 1549.3 nm and 1549.83 nm with a wavelength spacing of 0.53 nm.

掺铒光纤非均匀展宽引起的空间烧孔现象导致单波长激光并不能完全控制放大器增益，提出了一种新颖的自动增益控制掺铒光纤放大器的结构：即采用高双折射光纤布拉格光栅产生抽运光，其写制光栅的波峰对应的波长分别为1549.3 nm和1549.83 nm，波长间隔为0.53 nm。

Fiber grating coupler has good wavelength selection characteristic of optical fiber grating as well as multiport advantage of fiber coupler. These features make it easy to realize allfiber optical add/drop multiplex.

光纤光栅耦合器具有光纤光栅良好的波长选择特性和光纤耦合器的多端口特点，易于实现全光纤的光波分插复用。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48