基于多角度偏振信息反演海洋上空卷云云顶高度

采用偏振辐射信息反演云顶高度时,为了减小由云层及地表偏振辐射特性变化带来的反演结果不确定度,使用490 nm和865 nm通道多角度偏振信息反演卷云云顶高度.理论分析大气顶偏振特征,给出490 nm与865 nm通道偏振特性差异,说明使用此两通道偏振反射率差反演云顶高度的可行性.假设卷云为一般种类混合模型(General Habit Mixture,GHM),使用倍加累加矢量辐射传输模型计算和分析大气顶490 nm和865 nm通道偏振反射率差对卷云有效粒子半径、光学厚度和云顶压强的敏感性.分析表明,当卷云光学厚度大于3时,偏振反射率差对有效粒子半径和光学厚度的变化不敏感,对云顶压强变化敏感.根据敏感性分析结果选择适当的参数构建偏振反射率差查找表,使用查找表方法反演POLDER3数据的卷云云顶高度,并与POLDER3产品和MODIS产品进行比较.结果表明,与POLDER3的官方算法相比,使用偏振反射率差查找表方法有更宽的散射角适用范围,反演结果与MODIS产品有更好的一致性.     

用于星载太赫兹波被动遥感卷云参数的通道辐射特性及反演影响因素研究

太赫兹波是理论上遥感卷云微物理参数的最佳波段,但星载太赫兹波被动遥感的结果易受到非卷云因素(地表反射率、大气廓线、中低层水云等)的影响.利用辐射传输模式分别模拟计算了地表反射率、大气廓线、中低层水云对大气层顶太赫兹辐射光谱的影响,并基于多重查找表法定量分析了这些因素的变化所造成的反演误差.结果表明:地表反射率对太赫兹辐射光谱的影响主要集中在300 GHz以下,对反演所选取的波段没有影响;实际大气廓线中水汽廓线和温度廓线的改变对反演结果产生影响,当温度廓线的变化在±2 K范围以内,或水汽廓线变化±20%时,对于粒子尺度大于50μm、冰水路径大于10 g/m2的卷云,反演误差均保持在±20%以内;低云(云底高小于2 km)对所选通道的辐射没有影响,中云所产生的误差随着光学厚度和云底高度的增加而增大.     

卷云高度对大气的红外光谱辐射影响的研究

利用通用大气辐射传输软件(CART)计算了不同高度卷云大气红外光谱辐射亮温,着重分析了卷云高度对不同红外波段红外亮温谱、卷云有效尺度以及光学厚度反演的影响。研究发现:对流层顶以下,大气窗口波段的亮温随着卷云高度的变化和大气温度廓线基本一致,790~960 cm-1波段亮温的斜率随卷云高度的增加而变大。亮温差BTD[900~1 231 cm-1]对薄卷云和小的有效尺度随卷云高度的变化较明显。对于厚卷云,亮温差BTD[900~1 559 cm-1]随卷云高度的变化基本上不依赖于卷云有效尺度和光学厚度。在卷云参数的光学定量遥感中需考虑卷云高度变化的影响。     

基于MODIS参数的卷云光学厚度计算方法

卷云光学厚度是对全球气候、地球辐射收支影响较大的云光学参数之一.在军事、大气科学等领域对卷云光学参数的求解算法有广泛的应用需求.应用中分辨率成像光谱仪(MODIS)数据求解卷云参数的算法,多采用卫星多通道数据,数据处理过程较为复杂.为解决这一问题,利用RT3模型结合MODIS云参数,模拟计算卷云反射率,建立卷云光学厚度查找表,设计简单算法,实现了卷云光学厚度的有效反演.对比卷云光学厚度反演结果和MODIS实际测得的数据,可得两者相关性达到0.97,验证了此算法下卷云光学厚度反演的可靠性.选取MODIS不同时间段的数据,分析了卷云光学厚度在不同时间、空间范围的变化情况,平均误差小于0.16,进一步验证了基于RT3模型的查找表反演卷云光学厚度的有效性.研究结果有助于实现全球范围内卷云光学特性的简单有效反演.     

基于MODIS云参数的卷云反射率计算研究

卷云反射率是天气、气候和地球能量平衡研究中关注的重要参数。卷云反射率的快速算法在遥感反演卷云特性参数中具有重要应用。依据卷云反射率随卷云光学厚度、有效尺度、太阳天顶角、观测天顶角、相对方位角等参数的变化,利用离散坐标法（Discrete Ordinate Radiative Transfer method,DISORT）计算卷云反射率,预先建立卷云反射率随相关参数变化的快速查找表,以此建立了卷云反射率的快速算法。将MODIS卫星探测的卷云光学厚度、太阳天顶角、观测天顶角、相对方位角等因素作为输入参数,计算得到了卷云反射率,比较了计算的卷云反射率和MODIS实际测量的卷云反射率值,相关系数达到0.94,平均偏差小于18.5%,说明了卷云快速算法计算合理可行。     

1.064μm波长卷云反射率的模拟研究

为了给激光测距、激光对大气的探测等实际工程应用提供理论依据,采用逐线积分方法计算大气分子吸收,结合离散纵标法,并耦合卷云的单次散射特性,对由实心六棱柱状冰晶粒子组成的卷云在波长为1.064μm时的散射特性和辐射特性进行了理论分析,得到了该波长上激光在卷云中传输时的反射率随入射光源的位置、观测器的位置以及卷云参量(云光学厚度、粒子尺度等)的关系。结果表明,卷云在1.064μm附近对激光的主要影响是散射,吸收在消光中占了很小的部分;其次,卷云的散射明显改变了光辐射的空间分布,散射的方向变化主要由卷云的散射相函数以及光线入射角度和观测角度决定。这一结果对实际工程应用(比如激光测距、激光对大气的探测等)是有帮助的。     

激光雷达和毫米波雷达的卷云微物理特性的联合反演方法

联合激光雷达和毫米波雷达对卷云观测可以得到更全面的卷云特性信息,是卷云观测的一种发展趋势。使用美国大气辐射观测(Atmospheric Radiation Measurement,ARM)计划中卷云观测数据,将激光雷达和毫米波雷达反演的云边界信息相结合,得到更为准确的卷云边界信息。提出卷云微物理特性的激光雷达和毫米波雷达联合反演算法,该联合反演算法能在激光雷达不能穿透或毫米波不能识别卷云的情况下,反演出整个卷云的冰水含量、光学厚度。使用联合反演算法对一次卷云过程进行反演,其中激光不能穿透的区域冰水路径含量反演精度提高24%,毫米波雷达无法识别的区域冰水路径含量反演精度提高48%。在正确反演冰水含量的基础上,利用冰水含量、粒径分布与光学厚度的关系得到卷云过程的光学厚度,克服了由于卷云对激光雷达强衰减导致的光学厚度观测的困难。     

1.315 μm波长冰晶粒子辐射特性的模拟研究

利用逐线积分法(LBL)计算得到了大气分子红外吸收信息,结合不同形状冰晶粒子的单次散射特性,通过离散纵标法(DISORT),模拟计算了由实心六棱柱状冰晶粒子组成的卷云在波长为1.315μm时的散射特性和辐射特性,定性分析了激光在卷云中传输时的衰减和散射规律与入射光的位置、卷云光学厚度、冰晶粒子有效尺度等参数的关系。与晴天大气相比较,卷云的散射明显改变了光辐射的空间分布,被其他传感器探测到的可能性增大,其结果对于激光测距、激光探测等有关工程设计方面有非常重要的参考价值。     

紫外波段大气背景与目标特性研究

基于太阳紫外辐射在大气中散射模式理论,对紫外波段大气传输与背景变化进行了分析.分析了紫外辐射在不同波段与高度下,大气水平与垂直两个方向的传输特性.分析了不同波段的大气背景变化,以及不同季节、地理位置、地表反射率和气溶胶类型对大气背景的影响.     

中国典型地区大气光学特性及其应用

大气的光学性质决定了大气辐射平衡;各种先进光电技术的应用场景绝大部分都位于地球大气层内或通过大气路径,相关光电系统的功能受到大气光学特性不同程度的影响.大气光学特性(包括地表的光学特性和天空背景辐射特性)是光波在大气中传播和大气辐射传输研究必需的基础物理性质,在气象、气候和天文观测等基础和应用研究以及自适应光学技术、自由空间光通讯等光电工程应用中具有十分重要的作用.中国的自然环境十分复杂,相应的大气光学特性不能简单的套用国际上其它地区的模式.应进行中国大气光学特性的区域划分,在各个典型地区进行大气光学特性的系统测量和数据分析,对有关大量气象和大气光学特性观测资料进行分析研究,获得各典型地区大气光学特性的统计特征,建立可用于辐射大气传输、光波大气传播研究、光电系统分析与设计等的我国各个典型地区的大气光学特性的统计平均模式,研制光辐射大气传输及其光电应用软件包.     

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。     

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.     

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.     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

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.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.