Investigation on the Novel Technology of the Fiber Bragg Gratings and Applications in Optical Fiber Communications and Sensors

光纤光栅已经成为当前最具发展前途，最具代表性的光无源器件之一，在光通信与光传感领域都得到了广泛的应用。D形光纤光栅与基于光纤光栅的法珀结构是其中两种比较新型的技术，它们各自具有独特的性质，可以实际应用在许多场合，因此，研究它们具有重要的理论和实际意义。本文主要的研究工作体现在三个方面：一、光纤光栅波长解调技术及其应用的研究。研究了基于边沿滤波器及可调谐法珀滤波器的两种光栅波长解调技术，实验得到的波长分辨率分别为3.1pm和3pm。并且将这两种解调技术相结合，实际应用于桥梁结构健康监测。二、D形光纤光栅的弯曲敏感特性及其应用的研究。用材料力学理论详细分析了D形光纤光栅的弯曲敏感机理。实验测得其弯...Fiber Bragg gratings have become one of the most promising and representative optical passive devices at present, and have been broadly applied in optical fiber communications and sensors. The D-shaped fiber Bragg grating (D-FBG) and FBG based Fabry-Perot structure are two novel techniques, which can be applied in many areas for their special properties. So it is really important for theory and pr...学位：工学博士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2005140321

基于D型光纤Bragg光栅的加速度传感器

本文介绍了一种新型的基于d型光纤brAgg光栅(d-fbg)测量加速度信号的方案,并对测量系统进行了理论分析和实验测量。该加速度传感器具有尺寸小、质量轻、结构简单、灵敏度高等优点,可用于测量低频振动(0.1Hz数量级)和小幅值的加速度信号。试验数据表明基于该方案的测量灵敏度可达到563.67με/g,最小分辨力为1.15x10-3g

Tunable narrow linewidth fiber laser with two FBG-FPs

基于游标原理,利用一对自由谱宽(fSr)略有不同的光纤布喇格光栅法布里-珀罗腔(fbg-fP)作为模式选择器件,设计了一种新颖的环形腔光纤激光器。从理论和实验上研究了该激光器的特性。通过对可调谐fbg-fP应力调谐,在1552.240~1552.912 nM范围内,以96 PM为平均间距,获得了8个由固定fbg-fP的透射谱所确定的窄线宽稳定激光输出。8个输出波长的平均功率为-17.66 dbM,波动在0.7 db范围内。当泵浦光的功率为95 MW的时候,输出信号的信噪比均大于50 db。实验上每隔1 MIn用光谱分析仪(OSA)对输出光波长自动扫描,记录的输出光波长漂移在数皮米范围内,且功率的波动小于0.1 db。这种可调谐的窄线宽光纤激光器在光纤通信和光纤传感方面有潜在的应用价值。Using a pair of Fiber Bragg grating Fabry-Pérots(FBG-FP)with a little different FSR as its wavelength-selective components,a novel ring laser based on the vernier effect is proposed.We have studied the characteristics of this kind of tunable fiber laser both theoretically and experimentally,and obtained 8 discretely tunable laser wavelengths ranging from 1552.240 nm to 1552.912 nm with an average 96 pm span by pulling the tunable FBG-FP.The output spectrum peak is uniform among different wavelength at-17.66 dBm with a fluctuation of 0.7 dB.When the pump power is 95 mW,the signal-to-noise ratio is better than 50 dB.The output spectrum of the laser is recorded automatically by an optical spectrum analyzer(OSA)once a minute.It is found that the output wavelength drift within a few pico-meter and the fluctuation of the output power is less than 0.1 dB.This kind of fiber ring laser may have potential applications in optical communications and sensors.国家自然科学基金项目(No.61077031/F050208); 福建省教育厅B类科技研究项目(No.JB11097)资

Application of Hierarchical Modeling and Analysis Method in C4ISR System

C4ISR系统是一个规模庞大、层次分明的离散动态系统,文章提出了一种面向C4ISR系统的UML和Petri网结合的建模分析方法。该方法采用从上到下的层次分析方法,用扩展的UML模型对系统组织结构和系统的静态特征进行描述,用扩展的Petri网模型描述和分析系统动态特性,通过相应的规则将Petri网模型转化成状态图和序列图。新方法可以对系统要求进行验证,同时还可以编程实现。最后通过该方法,对一个C4ISR系统进行了建模分析。C4ISR system is a discrete dynamic system with large scale and clearly hierarchy,this paper presents the modeling and analysis method combining UML with Petri net for C4ISR system.This approach adopts a hierarchical analytical method with top-down techniques,describes the whole systemic structure and static property through extended UML model,shows systemic dynamic characteristic using extended Petri net then transforms to the correspondence state diagram and sequence diagram.New methods verify system requirement and easily realize its code.At last the approach is illustrated by its application to C4ISR system.国家“十五”计划基金资助项目(40405010101C

Preparation of Co-YSZ/HAp Nano-composite Coating on Ti Substrate by Electrochemical Method

采用复合电沉积和电泳沉积两步法在钛基体上制备了Co-YSZ/HAp纳米复合涂层,与只采用电泳沉积法在钛基体上制备纳米HAp单一涂层进行了比较研究.采用场发射扫描电镜、X射线衍射和能量散射谱对复合涂层的微观形貌,纳米HAp外层表面形貌,晶相,复合涂层的断面形貌及元素组成分布进行分析研究.通过粘结-拉伸实验测定了涂层与基体的结合强度,结果表明,Co-YSZ/HAp纳米复合涂层与钛基体的结合强度明显高于纳米HAp单一涂层与钛基体的结合强度,说明复合涂层具有更好的力学性能.Co-YSZ/HAp nano-composite coating and nano-HAp single coating were deposited on Ti substrate using the combination of electrocodeposition and electrophoretic deposition, and electrophoretic depositions, respectively. Surface and cross section morphologies of the coatings were observed by scanning electron microscope. Element distribution and crystal phase of the coatings were analyzed by energy dispersive spectrum and X-ray diffraction. The adhesive strength of the coating and Ti substrate was determined by shear strength testing. The results indicate that the adhesive strength of Co-YSZ/HAp nano-composite coating and Ti substrate is higher than that of nano-HAp single coating and Ti substrate. It shows that Co-YSZ as an interlayer reduces the mismatch of the thermal expansion coefficients between HAp and titanium and Co-YSZ/HAp nano-composite coating has better mechanical properties.国家自然科学基金(20573086,200273055);; 福建省自然科学基金(E0210004)资助项

一株高效抑藻放线菌的分离筛选及鉴定

从福建云霄国家红树林自然保护区滩涂沉积物样品中,共分离获得521株纯培养物.通过检测球形棕囊藻(Pha-eocystis globosa)荧光强度计算抑藻率,从521株菌中筛选到27株具有抑藻活性的菌株.在27株抑藻菌中,菌株O3-26对球形棕囊藻具有最高的抑藻率(高达96.71%).菌株O3-26的抑藻谱实验显示,该菌株抑藻活性表现出一定的种属特异性,对硅藻门(Bacillariophyta)的三角褐指藻(Phaeodactylum tricornutum)和中肋骨条藻(Skeletonema costatum)2株测试藻株没有抑制作用,而对绿藻门(Chlorophyta)盐生杜氏藻(Dunaliella salina)和自养小球藻(Chlorella autotrophi-ca)2株藻株具有较强抑藻作用.扫描电镜观察显示,该菌株孢子丝直至螺旋状且孢子表面带刺.生理生化实验显示,该菌株在所得到的大多数培养基上生长良好,在营养琼脂培养基中可以产生水溶性色素;不能在棉子糖作为唯一碳源的培养基上生长.16SrRNA基因相似性分析表明,菌株O3-26属于链霉菌属(Streptomyces),并与灭癌素链霉菌(Streptomycesgancidicus)15412菌株具有最高的同源性(99%).生理生化实验表明,二者之间生理特征存在一定差异.综合形态特征、生理特征以及系统发育分析的结果,鉴定该菌株为灭癌素链霉菌

Preparation of Co-YSZ/HAp nano-composite coating on Ti substrate by electrochemical method

Co-YSZ/HAp nano-composite coating and nano-HAp single coating were deposited on Ti substrate using the combination of electrocodeposition and electrophoretic deposition, and electrophoretic depositions, respectively. Surface and cross section morphologies of the coatings were observed by scanning electron microscope. Element distribution and crystal phase of the coatings were analyzed by energy dispersive spectrum and X-ray diffraction. The adhesive strength of the coating and Ti substrate was determined by shear strength testing. The results indicate that the adhesive strength of Co-YSZ/HAp nano-composite coating and Ti substrate is higher than that of nano-HAp single coating and Ti substrate. It shows that Co-YSZ as an interlayer reduces the mismatch of the thermal expansion coefficients between HAp and titanium and Co-YSZ/HAp nano-composite coating has better mechanical properties

Effects of alkaline-earth strontium on the performance of Co/Al_2O_3 catalyst for methane partial oxidation

联系作者: 余长林( 1974-) ，湖南炎陵人，男，博士，副教授。主要从事纳米催化新材料研究。Tel: 0797-8312334; E-mail: [email protected]。 本文的英文电子版由Elsevier 出版社在ScienceDirect 上出版( http: / /www.sciencedirect． com /science /journal /18725813) 。[中文文摘]以γ-Al2O3为载体,采用共浸渍法制备了Sr-Co/Al2O3系列催化剂,研究了助剂Sr对Co/Al2O3催化剂上甲烷部分氧化(POM)制合成气反应的影响,并利用N2物理吸附、X射线衍射、H2-程序升温还原和热重等技术对催化剂的理化性质进行了表征。结果表明,未添加助剂的Co/Al2O3和800℃焙烧的Sr-Co/Al2O3催化剂在POM反应初期催化活性很低,然而,当添加Sr的质量分数高于2%时,催化剂表现出很好的催化活性和稳定性。焙烧后的新鲜催化剂上主要存在两类Co物种,一类是与载体相互作用较弱、易被H2还原为单质的Co3O4;另一类是与载体相互作用较强、难还原、无催化活性的CoAl2O4尖晶石。在焙烧过程中,Sr易形成Sr4Al14O25,从而削弱Co与Al2O3之间的相互作用,能在一定程度上抑制CoAl2O4物种的形成,提高催化剂的稳定性和活性。未添加Sr的Co/Al2O3在反应时易发生物相改变生成尖晶石,导致催化剂迅速失活;但当焙烧温度达到800℃时,添加有限量的Sr还是无法阻止CoAl2O4的产生。[英文文摘]A series of Sr-Co/Al2O3 catalysts were prepared by co-impregnation method using γ-Al2O3 as the support.The effect of strontium promoter on the catalytic performance of Co/Al2O3 catalyst for partial oxidation of methane(POM) to synthesis gas was studied.The catalysts were characterized by some physicochemical characterizations such as N2 physical adsorption,X-ray diffraction(XRD),H2-temperature programmed reduction(H2-TPR) and thermogravimetry(TG).The results show that both Co/Al2O3 calcined at 700 ℃ and Sr-Co /Al2O3 calcined at 800 ℃ exhibit low activity and deactivate at the initial stage of POM reaction.The addition of above 2% mass fraction of strontium will greatly enhance the activity and stability of Co /Al2O3.Two types of Co species were identified on the fresh calcined catalysts.One is Co3O4 which weakly interacts with Al2O3 (easily reduced by H2) and the other is the spinel CoAl2O4 ( non-catalytic performance) which strongly interacts with the support.During the course of calcination，strontium can react with Al2O3 to form Sr4Al14O25 which will restrain the generation of the CoAl2O4 species and promote the stability and activity of catalysts．Without strontium promoter，CoAl2O4 is easy to be formed over Co /Al2O3 in the POM reaction.However，the formation of CoAl2O4 cannot be avoided with the addition of limited strontium when the calcination temperature is over 800 ℃．国家自然科学基金(21067004,21263005); 厦门大学固体表面物理化学国家重点实验室开放基金(200906);; 江西省自然科学基金(2010-GZH0048); 江西省教育厅科技项目(GJJ12344); 江西省青年科学家培养对象资助(20122BCB23015