脑电信号反馈控制装置的设计

本文研究设计了专用于治疗神经系统脑部疾病的智能化离电信号反馈控制装置。在分析人体脑电信号的基础上，将脑电生物反馈与电磁反馈有机结合，能有效地调节脑神经细胞的电活动。临床研究表明，该装置对神经系统一些脑部疾病有显著疗效。     

数字化动态脑电地形图系统的应用研究

根据当代医学理论及经验，人体大脑发出的微弱电信号直接和人体的某些病症有联系。但是人体头皮电位只有几十微伏，需放大十几万倍才能被记录到。数字化脑电地形图仪实现了对人体头皮信号的采集，通过放大器将电信号放大，并将连续变化的脑电波变成计算机能识别的离散的二进制数值，通过脑电地形图的形式提供脑电波的定量和定性分析。根据对实际项目的研究，描述了脑电地形图系统的工作原理，并提出了一个实现的解决方案。     

基于TGAM模块的脑电信息沟通系统设计与实现

本文设计与实现了一种基于TGAM模块的脑电信息沟通系统。该系统采用美国神念科技的TGAM芯片,基于SSVEP-BCI脑电范式,完成了从脑电信号采集,到脑电信号处理分析,以及脑电信号运用的一整套脑波控制的标准化流程,实现了将脑波"意念"转化为他人可直观解读的个人需求信息或意愿信息的目的。     

3D影片中背景视差过大对人体健康影响的脑电评估研究

通过采集志愿者观看背景视差过大的3D影片前后的脑电数据,来研究该效应对人体健康的影响。实验共选取20例有效样本,利用快速傅里叶变换法(FFT)提取特征波段,计算出各频带的能量和功率,并由此得到功率谱和重心频率。此外还设计问卷定性了解志愿者的疲劳程度。根据主观疲劳问卷和对比看前看后的脑电参数,分析了观看背景视差过大的3D影片后人体脑电信号变化的关系。实验结果表明志愿者看前看后的各项脑电参数出现了改变,并全部主观反映出现疲劳。因此脑电参数结合主观问卷可成为3D影片疲劳评估的参考指标。     

一种基于脑电信号反馈的学习注意力提升训练方法实现

注意力对于学习者来说非常重要,注意力与脑电信号密切相关,注意力可通过训练得以提升。文章提出一种基于移动智能终端应用APP脑电信号反馈的训练系统,训练包含舒尔特方格和算数运算两种方式,训练中可实时查看训练者脑电反馈的注意力状态信息,强化训练效果。实践结果表明,注意力和脑电信号之间存在正向相关性,训练者经过长时间训练其注意力能够得到显著提升,训练还能够提高训练者快速调整其注意力状态的能力。     

通用串行总线脑电信号采集电路设计

脑电信号的准确采集对于研究人脑活动、诊断疾病至关重要.针对脑电信号的特征,设计出使用16路电极提取脑电信号,采用高精度仪用放大器实现三级放大,设计有源双T陷波电路来抑制50 Hz工频干扰,设计光电隔离电路和16住A/D转换电路及USB接口电路.该电路实现了脑电数据的准确采集、高速传输和实时处理,有效解决了传统脑电数据采集系统速度慢,处理功能简单,数据存储量小,连接复杂等缺陷,满足了实际需要.     

面向多动症儿童的脑电控制产品设计

目的:设计一款面向多动症儿童注意力培养的脑电控制玩具产品。方法:儿童对注意力的自我控制能力取决于其大脑神经元细胞网络链接与稳定程度,这个神经元网络链接的稳定经过强化训练可以得到固化。基于脑机交互技术构建儿童思维训练产品,通过检测脑电波数据,来控制玩具产品的运动状态,使孩子的注意力在娱乐的过程中得到提升。结果:基于脑电信号采集和交互控制技术,设计并制作了面向儿童关注力训练的脑电玩具产品,并进行了相关测试实验。结论:本产品达到培养孩子注意力的目的,弱化儿童注意力障碍,减轻生活中因为意力不集中而产生的负面影响。     

基于头皮拉普拉斯脑电电极的高空间分辨率SSVEP信号采集与分析研究

脑电信号（Electroencephalogram,EEG）因其具有时间分辨率高、方便易得等优点被广泛应用。然而脑电信号的空间分辨率较低,导致其应用效果受限。拉普拉斯滤波方法已被证明可提高体表电位的空间分辨率。传统拉普拉斯脑电研究通常利用算子来估计圆盘电极阵列中的拉普拉斯电势。但是圆盘电极间距大,使得该方法估计结果精度较低。针对上述问题,本文设计了一种拉普拉斯脑电电极及其采集方案,分别从仿真实验和人体实验两方面验证了其有效性。仿真结果表明拉普拉斯电极空间分辨率可比传统圆盘电极提高约41.4%。人体实验结果表明大脑左右半球视觉皮层同时产生稳态视觉诱发电位（Steady-state visual evoked potentials, SSVEP）时,拉普拉斯脑电信号可明显分辨出左右半球两个独立的SSVEP源信号,而传统脑电信号无法区分这两个独立脑电源。上述研究结果证明,本文设计的拉普拉斯脑电电极及其采集方案能够有效提升脑电的空间分辨率,有望实现更精确的脑电源定位。     

新型脑电信号放大检测电路的设计

通过对前置放大器等电路结构的精心设计,选用超低噪声的集成运算放大器以及线性光耦合器等新器件,克服了脑电信号采集中常遇到的一些困难,使前置放大器具有较高的共模抑制比,从而能够较好地放大检测出的脑电信号.通过Pspice仿真软件,有助于电路的设计和调试.     

基于小波分析的脑电信号处理

为去除脑电信号采集过程中存在的噪声信号,提出了基于小波阈值去噪的脑电信号去噪。以小波阈值降噪为基础,首先利用db4小波对脑电信号进行5尺度分解,然后采用软、硬阈值与小波重构的算法进行去噪。通过对MIT脑电数据库中的脑电信号进行仿真,结果表明,采用软阈值方法有效去除了噪声,提高了脑电信号的信噪比。     

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.