用光声光谱法研究环氧树脂固化

本文报导用近红外光声光谱技术研究环氧树脂加聚酰胺的固化的实验结果,分析表明,位于2.39μm和2.54μm的组频吸收峰可作为特征峰来描述固化过程,同时也表明,光声光谱技术是研究高聚物固化的一种简便迅速手段.     

氩激光激发自体荧光诊断口腔癌的适用性研究

用一种快速检测活体组织荧光光谱的技术,分析人口腔的恶性肿瘤、癌前病变、良性疾患和各种正常组织的氩激光激发自体荧光光谱,讨论以卟啉峰为特征诊断恶性肿瘤时,某些假阳性、假阴性病例产生的原因和鉴别的方法。     

激光诱导化学气相沉积纳米硅的红外光谱

对激光化学气相沉积纳米硅的红外光谱进行了研究，结合红外光声光谱考察了退火处理对其红外光谱吸收峰位置的影响，对纳米硅的红外吸收峰进行了标识和讨论。     

人体食道和乳腺组织的时间分辨光谱研究

实验研究了在514nm波长激发下人体食道和乳腺组织，包括正常组织和癌变组织的时间分辨光谱。由时间分辨光谱拟合求得的特征峰荧光寿命结果表明：食道正常组织和鳞癌组织的荧光寿命分别为2.09ns和1.71ns，乳腺正常组织和腺癌组织的荧光寿命分别为2.05ns和1.43ns。正常组织的荧光寿命都大于癌变组织的荧光寿命，它们之间存在明显差异，这一方法将有助于结合稳态荧光光谱应用于早期癌变组织的精确诊断。     

基于拉曼光谱的鼻咽癌与正常鼻咽细胞株的分类研究

高空间分辨率的共聚焦显微拉曼光谱技术从分子水平上提供了生物分子成分和结构的指纹性信息。以鼻咽癌细胞株C666-1、CNE2和正常鼻咽细胞株NP69为对象,利用拉曼光谱探索和分析癌细胞株与正常细胞株之间的差别。结果表明:谱峰比I1449/I1657(1.10)可以准确地将鼻咽癌与正常鼻咽细胞株分成两组,这一结论与相关支气管癌组织的报道结果一致;此外,采用主成分分析方法说明3种细胞株的拉曼光谱之间存在统计学差异,并以线性判别分析方法对其进行统计划分,灵敏度和特异性分别达到90%和100%。这些结论可以为拉曼光谱技术用于NPC的临床诊断提供依据,并有可能为鼻咽癌的早期诊断提供有益参考。     

紫光LED激发孟加拉红诊断早期口腔肿瘤

采用405 nm发光二极管(LED)作为激发光源,选用孟加拉红(RB)作为光敏剂,可对早期口腔肿瘤进行诊断.正常的口腔黏膜不会被孟加拉红染色,而当口腔产生癌前病变或者生成肿瘤时,孟加拉红就会将病变部位染色.通过光谱测量可知,被染色病变部位的特征荧光光谱波长范围为570～600 nm,而正常口腔组织的特征荧光光谱中心波长约在480 nm.当癌前病变发展成恶性肿瘤之后,其特征荧光光谱发生改变,在630 am和690 nm处各有一个典型的卟啉峰.以此为依据并结合光致荧光技术,采用荧光比例法,可以对口腔癌前病变进行诊断,灵敏度和特异性分别可达到95%和92.5%.这种无创、快速、早期的诊断方法,可以显著提高口腔癌患者的存活率.     

乳腺疾病患者血清的紫外吸收谱分析

测量了不同乳腺疾病患者血清的紫外吸收谱。人血清的紫外吸收谱约在230nm附近有一极强的吸收峰，在279nm有一较强的吸收峰，该吸收峰为蛋白质芳香族氨基酸的特征，在253nm有吸收谷。分析表明，不同乳腺疾病患者血清的紫外吸收谱有差异。血清紫外吸收谱的279nm吸收峰位及1279／1253的差异，反映了样品中芳香族氨基酸的成分及含量的差异；有无414nm吸收峰的差异主要反映了样品是否有溶血发生。这些光谱差异对于乳腺疾病光谱诊断的研究具有参考价值，为应用光谱技术进行血清检测，诊断疾病寻求简便的方法和途径。     

激光诱导击穿光谱谱峰元素自动识别方法研究

激光诱导击穿光谱(LIBS)中通常含有丰富的元素特征谱峰,谱峰的准确识别是利用LIBS技术进行元素定性、定量分析的前提和基础。针对传统谱峰元素识别方法准确率偏低、可靠性不足的缺点,提出了一种元素谱峰自动识别的新方法。该方法首先利用Voigt函数对实验光谱进行拟合,以克服谱峰重叠和噪声干扰;通过滤波处理后提取拟合谱峰的中心波长、光强、半峰全宽和谱峰质心作为谱峰特征参数向量,并将待识别光谱的谱峰特征参数向量与美国国家标准与技术研究院(NIST)标准谱线数据库中的元素谱线进行相似性分析,从而实现谱峰元素的自动识别。分别利用NIST标准数据库和茶叶样品LIBS光谱数据进行实验研究,验证了该方法在LIBS谱峰元素识别上的有效性。     

冻害胁迫小麦的图谱特征解析研究

冻害是造成中国农业生产重大损失的气象灾害之一, 对国内粮食安全生产造成严重威胁。利用图像处理技术提取冻害前后小麦的覆盖度特征, 用高光谱技术研究冻害前后小麦的光谱变化特征并确定遥感诊断的敏感波段。研究结果表明: 可见光波段的绿、红光可用于诊断冻害胁迫, 尤其在绿峰与红谷位置表现明显;近红外波段是判断冻害胁迫的敏感区间。综上, 光谱分析结合图像处理技术用于田间小麦冻害特征区间提取是可行的。     

癌细胞的激光荧光光谱特性研究

研究用于癌症诊断与治疗的光敏剂血卟啉(hematoporphyrin derivative,HPD)对人体癌细胞与正常细胞的亲和性,采用超短脉冲激光光谱技术和皮秒时间相关单光子计数系统,测量经血卟啉培养的活体癌细胞与正常细胞的荧光光谱,观测到癌细胞样品在645nm处具有特有的光谱谱峰;测量不同浓度血卟啉荧光光谱,观测到随着血卟啉浓度的逐渐增大,在645nm处出现的光谱峰也随之显著增强。对荧光光谱的二阶导数光谱进行分析,发现癌细胞与浓度2×10-1mg/ml血卟啉的二阶导数光谱图形状相似,说明在癌细胞内部血卟啉浓度增大了约2个数量级。测量数据表明癌细胞对血卟啉有很强的亲和性,同时还得到了亲和性的量化值。测量结果确认了荧光光谱技术诊断与治疗癌症的可行性,并对化疗注射光敏剂药液浓度的计量提供参考。     

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.     

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 sub-pixel 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.     

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.     

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。     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.