一类3涡卷混沌吸引子产生与同步的研究

提出利用符号函数产生3涡卷混沌吸引子的方法,进行基本的混沌动力学分析,给出最大李雅普诺夫指数、功率谱、庞加莱映射,并基于李雅普诺夫稳定性理论,研究了两个3涡卷混沌吸引子的单向耦合同步的问题,给出3涡卷混沌吸引子产生及其同步的数值模拟结果.     

简并光学参量振荡器的同步研究

通过计算简并光学参量振荡器系统的李雅普诺夫指数,证明了该系统存在混沌和超混沌吸引子,即简并光学参量振荡器是混沌系统,并得到了系统处于混沌状态时的参数取值范围.进一步,利用反馈技术实现了简并光学参量振荡器的混沌同步和周期同步,给出了反馈控制的具体形式并进行了仿真计算,理论结果与数值仿真结果一致.     

一种混沌系统的控制方法

系统的李雅普诺夫指数可用作判断系统是否混沌的依据，通过改变系统李雅普诺夫指数改变系统的运动状态，达到控制混沌系统的目的，理论分析和仿真实验结果均表明，该控制策略是有效的，可以实现系统的快速稳定。     

一个新的混沌模型及其硬件实现

该文提出了一个新的非线性动力学系统模型并对其进行了仿真研究,结果表明此模型具有正的李雅普诺夫指数,表现出时域伪随机性和连续的频谱,因而此模型是一个混沌发生器。由于它的线性子系统的条件李雅普诺夫指数均为负,因而是可同步子系统,能够用于混沌保密通信。该文还给出了此模型的两种分段线性电路实现方法。     

注入激光系统的混沌与超混沌行为

通过对一个注入激光系统的分岔图、李雅普诺夫（Lyapunov）指数谱、功率谱和相轨道的数值计算与分析，得到了系统出现不动点、极限环、混沌、超混沌的参数区间。为进一步研究该系统在混沌和起混沌状态下的统计性质奠定了基础。     

对一个新的平方混沌类的研究

该文提出一个新的平方混沌类,计算了混沌类的李雅普诺夫指数,并对混沌类中结构III所表现出的环面破裂产生混沌和倍周期分岔产生混沌的现象进行了初步的研究,在同一个系统中可以观察到环面破裂和倍周期分岔两种不同的通向混沌的路线,这尚属首次报道。     

取样鉴相数字合成器环中的混沌动力学行为

分析和研究取样鉴相数字合成器环中的混沌动力学行为,根据Ushio与Hira等人的方法,从理论上证明了当系统参数满足一定条件时,系统会出现分岔现象,并具体计算出系统在各个不动点处的Hopf分岔集、系统的李雅普诺夫指数以及豪斯道夫维数。通过对系统进行计算机模拟,观察到系统的奇异吸引子,奇异吸引子的自相似性,系统在混沌状态下对初始条件的灵敏依赖性,进一步证实了三角形取样鉴相数字合成器环中存在混沌现象。     

非线性RLC串联电路中混沌现象的研究

通过回顾混沌现象的历史研究,介绍了混沌的Li-Yoke定义及其特征;分析了非线性RLC串联电路的电路方程和参数.并利用梅利尼科夫(Melnikov)方法推断出非线性RLC串联电路中存在的混沌现象.最后通过计算机模拟结果证实了该方法的有效性.指出采用数值方法求得的李雅普诺夫(Lyapunov)指数存在正指数,这更加说明非线性RLC串联电路中存在着混沌现象.     

一类混沌系统的动态输出反馈控制

为了对一类混沌系统实施控制,提出了利碍新的控制器来控制混沌系统。以往的混沌控制方法只针对个别特殊的混沌系统,而利用动态输出反馈的方法能控制一类混沌系统,这方面的工作以前也曾有过。利用李雅普诺夫稳定理论,结合线性矩阵不等式优化方法,分析了系统的稳定性。数值仿真也表明了所提出的控制策略的有效性。     

基于Matlab的控制系统稳定性判定

介绍了控制系统稳定性的概念;论述了在经典控制理论中常用的代数稳定判据、根轨迹法、Bode图在判定控制系统稳定性中的联系和区别;也介绍了在现代控制理论中李雅普诺夫理论在控制系统稳定性判定中的应用.提出了用Matlab软件对代数稳定判据、根轨迹法、Bode图、李雅普诺夫理论进行控制系统稳定性判定的方法.对于各种稳定性判定方法简单明了地提出他们的概念,对代数稳定判据、根轨迹法、Bode图、李雅普诺夫理论等的应用具体化,给出相关例子、程序和相应几何图形.论述了根据Matlab计算结果来判定稳定性的方法.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.