Study of ICP-induced In doping and the properties of GaN-based LED wafers and devices

GaN材料属于第三代半导体材料，具有宽的直接带隙以及优异的物理和化学性质，是制作发光器件和光伏器件的理想材料。在信息显示领域，GaN基高亮度蓝、绿发光二极管可以用于户外大屏幕全色显示以及交通信号灯等方面；在照明领域，GaN基白光LED可以用于背光源、路灯和景观照明以及通用照明等。GaN基器件的研究已经取得巨大进展，但是在器件的制备过程中仍存在一些问题，如GaN材料的p型欧姆接触问题则是限制GaN器件发展的主要因素之一。有两方面的原因阻碍低阻p-GaN欧姆接触的实现：一方面是难以生长高空穴浓度的p-GaN材料；另一方面是缺乏合适的接触金属材料。目前用于提高p-GaN材料空穴浓度的方法主要有热退火...GaN-based wide-band gap semiconductors belong to the third generation of semiconductor materials, which are the ideal materials of emitting devices and photovoltaic devices because of their excellent physical and chemical properties. In the field of information display, GaN-based high-brightness blue and green light emitting diodes (LEDs) can be used in outdoor large screen display and traffic lig...学位：工学硕士院系专业：信息科学与技术学院_光学工程学号：2312012115289

Research on the PID Controller with Incomplete Derivation of Three-ax is Dispensing Machine System

中文摘要: 设计不完全微分P ID控制器,利用MATLAB工具箱进行点胶机的三轴平台的稳定性仿真。仿真结果表明,利用该方法所整定的控制系统具有良好的性能,其运行过程中的鲁棒性,抗干扰能力得到了很好的实现。英文摘要：Abstract: The PD controller with incomplete derivation is designed in this paper. The stability of three－ax is dispensing machine is simulated by using the MATLAB toolbox. Simulation results show that the tuning control system has good performance. It realizes robustness and disturbance attenuation in the running process.福建省自然科学基金(A0510002

Reduced-order Observer-based H_∞ Controller Design for Descriptor Systems

本文研究基于Luenberger观测器的广义系统降阶H∞控制器的设计问题,并且该观测器是关于干扰解耦的。首先是提出了广义系统H∞状态反馈控制问题的一个充要条件,并利用线性矩阵不等式方法求解出广义系统的H∞状态反馈增益。然后对该H∞状态反馈增益进行渐进降阶观测,基于广义Sylvester矩阵方程的显式通解的参数化设计方法,实现了广义系统的降阶H∞控制。本文最主要的工作是给出了相应的广义线性系统降阶H∞控制器的设计算法。在文章的最后给出了一个例子,用来说明降阶算法的有效性。This paper presents the design of a robust reduced-order Luenberger observer-based H∞ controller for the descriptor system.This observer is with disturbance decoupling.A necessary and sufficient condition for the H∞ state-feedback control problem of descriptor systems is established.Based on the parametric design approach for generalized Sylvester matrix equations,a reduced-order H∞ controller for descriptor systems is obtained.One major contribution of the present work is that a design algorithm for constructing the reduced-order H∞ controller is presented.An illustrative example is also given.福建省自然科学基金(A0510002)资助;; 厦门大学985二期信息创新平台项目资助;; 福建省新世纪优秀人才支持计划资

基于矫正广义走廊的电动倾转旋翼机模态转换

研究了基于矫正广义走廊和在线增益调度方法的电动倾转旋翼机模态转换控制问题。针对传统配平方法导致模态转换过程中时变动态特征被忽略的不足,提出一种新的两步法配平策略,即矫正配平工作点,并获得矫正广义走廊,以减小系统实际运行状态与配平工作点的偏离程度,进而改善增益调度方法的控制效果。传统增益调度方法控制器设计工作量较大,针对该问题设计了在线增益调度算法,有效避免了拟合过程。对某小型电动倾转旋翼无人机(UAV)的仿真表明,基于所提方法使得倾转旋翼机平稳、快速地完成模态转换过程;实验数据进一步表明,矫正后广义走廊相比于矫正前可将对过渡走廊的平均跟踪误差显著减小。国家自然科学基金(61673325,61374037)~

NMR Studies on Interactions between Diperoxovanadate Complex and 3-Substituted Pyridines

为探讨有机配体上取代基团对反应平衡的影响,在模拟生理条件下(0.15mol/LNaCl溶液),应用多核(1H、13C和51V)多维(DOSY)以及变温NMR技术研究双过氧钒配合物[OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(简写为dpV)与3-取代吡啶的相互作用,并首次报道了一些物种的NMR化学位移.dpV与有机配体的反应性从强到弱的顺序为:吡啶>烟酸根>烟酸甲酰胺≈烟酸甲酯,这说明吡啶环上取代基影响反应平衡.竞争配位导致一系列新的6配位的过氧钒物种生成.密度泛函计算结果合理地解释了实验结果,并表明溶剂化效应在反应中起重要作用.To understand the substituting group effects of organic ligands on the reaction equilibrium, the interactions between a diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)]- (abbr. dpV) and a series of 3-substituted pyridines in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, DOSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. Some direct NMR data were given for the first time. The reactivity among the 3-substituted pyridines towards dpV takes the order of pyridine>nicotinate>N-methyl nicotinamide≈ methyl nicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O2)2L]n- (L=3-substituted pyridines, n=1 or 2). The results of density func-tional calculations provided a reasonable explanation of the relative reactivity of the 3-substituted pyridines. Solvation effects play an important role in these reactions.国家自然科学基金(Nos.20772027,20803020);; 973子课题(No.2003CB716005);; 湖南省自然科学基金(No.06JJ30004);; 中国博士后科学基金(No.20070410805);; 湖南省教育厅青年项目(No.06B028);; 固体表面物理化学国家重点实验室资助项目;; 湖南科技大学博士基金(No.E-55107)资助项

NMR Studies on Interactions between Diperoxovanadate and Imidazole-like Ligands

为探讨咪唑环上取代基团对反应平衡的影响,在模拟生理条件(0.15 mol·L~(-1)NaCl溶液)下,应用多核(~1H、~(13)C和~(51)V)、扩散排序谱(DOSY)以及变温NMR等谱学技术研究双过氧钒配合物NH_4[OV(O_2)_2{2-(2'-Pyri-dine)- [midazole}]·4H_2O(简写为bpV(Imi-Py))和咪唑类配体(咪唑、2-甲基-咪唑、4-甲基-咪唑和组氨酸)的相互作用,其从强到弱的顺序为咪唑≈4-甲基-咪唑>2-甲基-咪唑>组氨酸.研究结果表明,咪唑环上取代基团空间位阻对反应平衡产生较大影响,同时竞争配位的结果导致新的6配位过氧物种[OV(O_2)_2L]~-(L为咪唑类配体)的生成,当配体为4-甲基-咪唑和组氨酸时,生成的则是一对异构体.To understand the substituting effects of imidazole ring on the reaction equilibrium,the interactions between diperoxovanadate complex NH_4[OV(O_2)_2{2-(2'-Pyridine)-Imidazole}]·4H_2O (abbr.bpV(Imi-Py)) and a series of imidazole-like ligands (imidazole,2-methyl-imidazole,4-methyl-imidazole,and histidine) in solution were explored using multinuclear (~1H,~(13)C,and ~(51)V) magnetic resonance,diffusion ordered spectroscopy (DOSY),and variable temperature NMR in 0.15 mol·L~(-1) NaCl ionic medium for mimicking the physiological conditions.The experimental results indicated that the activities of bpV(Imi-Py) and organic ligands were as follows:imidazole≈4-methyl-imidazole>2-methyl- imidazole>histidine.The stedc effect of the organic ligands affects the reaction equilibrium.At the same time,new six- coordinated peroxovanadate species [OV(O_2)_2L]-(L=imidazole-like ligands) were formed due to the competitive coordination between 2-(2'-pyridyl)-imidazole and the imidazole-like ligands.When the ligand was 4-methyl- imidazole or histidine,a pair of isomers was formed.国家自然科学基金(20772027);; 973子课题(2003CB716005);; 湖南省自然科学基金(06JJ30004);; 中国博士后科学基金(20070410805);; 湖南省教育厅青年项目(068028);; 卫生部(福建省)卫生教育联合攻关计划(3502220051027);; 厦门市重大疾病攻关研究基金(Wkj2005-2-019);; 固体表面物理化学国家重点实验室开放基金和湖南科技大学博士基金(E55107)资

H_∞State Feedback Control for Linear Singular Systems With Time-delay in State

首先利用线性矩阵不等式(LMI)方法,给出线性广义时滞系统稳定的一个充分条件;然后讨论广义时滞系统的H_∞状态反馈控制,给出控制器存在的充分条件,同时给出控制器的设计.控制器可由矩阵不等式解得。Using the method of linear marx inequality(LMI),H_∞state feedback control problem for linear singular systems with time-delay in state is discussed.A sufficient condition which guarantees the asymptotical stability of the closed-loop system is given.Furthermore,one sufficient condition for the existence of an H_∞state feedback controller is shown.The controller can be obtained via solving matrix inequality

利用ICP进行In掺杂对GaN基LED材料性能的影响

本文主要介绍一种新型的改善gA n材料P型欧姆接触特性的方法,即采用电子束蒸发技术在In gAn层上沉积一层ITO薄膜,然后通过感应耦合等离子体技术(ICP)对ITO进行轰击。通过XPS测试分析可知,ICP轰击ITO过程中,ITO中的In原子扩散至P-gA n层。通过在P-gA n上方制作欧姆接触并进行I-V测试,结果表明In掺杂后样品P型欧姆接触特性得到改善

An Empirical Study on Market Development,Enterpriser Political Characteristic and Political Connection of Chinese Private Enterprises

以市场化环境及企业家政治特征的视角,分析我国民营企业建立政治关联的动机。研究发现,我国各地区的市场化进程等制度环境深刻影响民营企业政治关联的建立。市场化程度越低、政府对市场和企业干预程度越高、非国有经济发展程度越低、金融业市场化程度越低和法律保护环境越弱的地区,民营企业政治关联的程度越高。研究还发现,政治关联型企业家控制的企业,其政治关联的程度也较高。This paper analyzes Chinese private enterprises incentive of establishing political connection from the aspects of institutional background and the enterprisers' political characteristics.Empirical study finds that institutional background like the process of China's market transition greatly affects the establishment of private enterprises' political connection.In a less developed market with less legal protection,a high government interference degree and a poor non-state economy will lead to a high degree of political connection of private enterprises.Meanwhile,research also finds that enterprises owned by enterprisers of political connection type have a higher degree of political connection.国家自然科学基金资助青年项目(70802011);福建省社会科学基金资助项目(2009B2018

顺磁-上转换发光复合纳米粒子及其制备方法和应用

本发明公开了一种顺磁-上转换发光复合纳米粒子及其制备方法和应用，其制备方法包括：将具有顺磁性的纳米粒子或者用于制备具有顺磁性的纳米粒子的原料与具有上转换发光性质的纳米粒子或者用于制备具有上转换发光性质的纳米粒子的原料通过反应复合，制得顺磁-上转换发光复合纳米粒子。该方法所制备的顺磁-上转换发光复合纳米粒子是一种具有MRI造影和上转换发光双重性质的复合纳米材料，其中的顺磁纳米粒子组分具有T1或T2加权的MRI造影功能，可用作磁共振成像造影剂和光动力治疗的纳米材料