瑞利激光雷达探测大气温度算法分析

介绍了瑞利激光雷达的基本结构，描述了使用瑞利散射激光雷达探测平流层和中间层低部大气温度的数据处理方法，构建同时包含标准大气模式温度信息和实际探测背景噪声的模拟数据，对此模拟数据进行背景扣除、平滑去噪、参考点选取等计算分析，探讨提高温度反演精度的实用算法。并应用此数据处理方法对瑞利激光雷达的实际测量数据进行了计算处理，将计算结果与模式CIRJA86、HALOE卫星数据进行对比分析，反演高度30～45km时误差1—3K，45～65km误差大约在2—5K，65—70km误差〈10K。     

激光雷达光束自动准直系统设计与实现

根据激光雷达原理并结合实际实验经验,设计了一套在计算机程序控制下的激光雷达光束自动准直系统.通过控制激光发射导向镜的位置,使激光在东西和南北方向扫描,对接收到的回波信号分析处理,得到最后方位使收发系统平行.操作过程每次只需10～20 min,精度可达到0.1 mrad.系统应用到大气温度监测中,将测量计算结果与模式CIRA86数据进行对比分析表明,反演高度30～45 km处误差1～3 K,45～65 km处误差2～5 K.     

基于拉曼激光雷达的南京上空大气温度廓线观测

介绍了综合使用瑞利、拉曼、米散射三种技术的激光雷达的基本结构与拉曼散射温度反演原理。对其中的拉曼回波信号进行了背景噪声扣除、滑动平均和小波变换降噪,在此基础上分析了气溶胶对拉曼激光雷达温度廓线反演的影响。利用上述激光雷达信号处理方法对南京上空的温度廓线进行观测,反演了2010年11月19日18时53分至19时35分连续观测的数据。反演的温度廓线表明,观测开始至观测结束,5.5 km处的温度变化为2 K的波动变化;对2010年11月整月的观测数据进行分析处理,得到11月份上中下三旬的平均温度廓线。在10 km高度处,下旬温度比上旬温度低4 K,随着入冬的进程,低空段的大气温度递减率有明显增大的趋势;11月的月平均温度在5~10 km处低于模式值4 K左右,并且两者几乎平行,说明11月份5~10 km各高度温度比模式均低4 K左右。     

瑞利-拉曼散射激光雷达探测大气温度分布

介绍一台用于夜晚探测大气温度分布的L625瑞利-拉曼(Rayleigh-Raman)散射激光雷达。采用Nd：YAG激光器三倍频输出355nm作为发射激光，利用弱光子计数技术检测大气中分子的瑞利散射和N2分子振动拉曼散射回波，分析得到了平流层和对流层中上部大气温度的垂直分布廓线。其观测结果分别与HALOE／UARS卫星和无线电气象探空仪结果进行了对比分析。其中，激光雷达观测的平流层温度与HALOE卫星的结果对比表明，它们在高度25～65km内显示出较好的一致性，20个夜晚的平均温度差别基本上小于2K。激光雷达与无线电气象探空仪探测的对流层温度在高度为5～18km内反映了较为一致的分布趋势，15个夜晚的平均温度差别在6～16．5km高度内小于3K。这些结果表明，L625瑞利-拉曼散射激光雷达观测数据可靠，可用于大气温度分布的常规观测和分析研究。     

瑞利散射激光雷达强光感生噪声修正的新方法及大气温度探测

借助一套全新的地面高精度光电探测器强光感生噪声检测平台,建立了强光感生噪声精细结构扣除模型,同多通道信号接收技术相结合,改进了一台用于中高层大气温度探测的子午工程双波长三通道瑞利散射激光雷达数据的处理方法。处理后数据反演的大气温度廓线与TIMED卫星结果相比较,得到了很好的吻合。在35~85km高度范围内二者反映了较一致的温度分布特征,30~55km温度误差小于±5K,55~75km温度误差小于±10K。     

高光谱分辨率激光雷达测量低层大气温度

基于碘分子滤波器对大气气溶胶散射的强吸收特性,滤除低层大气中气溶胶散射的影响,从而利用分子瑞利后向散射信号强度反演低层大气温度.激光雷达低层大气温度测量结果与探空数据进行了对比,显示出较好的一致性,温度偏差在9 km内不大于3 K.讨论了激光雷达测得的大气温度与探空数据对比结果之间存在的系统偏差和由于参考高度温度初始值引起的激光雷达温度反演结果的变化.     

钠多普勒激光雷达大气参数反演方法

钠多普勒激光雷达以75～110 km大气层中的Na原子为示踪物,由接收到的共振荧光散射回波光子数反演该高度范围内大气温度、风场及钠原子数密度廓线.研究钠激光雷达大气风场和温度反演的方法,分析激光雷达光子计数中的脉冲堆积效应和钠层吸收对反演结果的影响,并提出改正方法.将该方法用于美国伊利诺斯大学激光雷达实测数据的反演,反演结果与该大学的结果相符合,验证了反演方法的正确性.最后对测量数据进行了误差分析,给出噪声光子数引起的误差剖面及实验测量精度.     

白天天空背景光变化特性的理论计算与实验测量

通过理论推导得到了竖直方向上白天天空背景光光强计算公式。根据激光雷达30km处的瑞利数据反演了30km以下的大气透过率,利用反演出的大气透过率和推导的背景光计算公式,计算了天空背景光的白天变化,与实测数据符合较好。同时也说明了白天用FADOT窄带激光雷达探测有限距离大气透过率的可行性。     

探测边界层大气温度的转动喇曼激光雷达

为了研制一种测量边界层大气温度的激光雷达,采用氮气和氧气的转动喇曼谱的强度比反演大气温度垂直分布的方法,对转动喇曼激光雷达系统进行了理论分析与实验研究,取得了边界层内的大气温度数据。结果表明,该激光雷达测量的大气温度在0km~2.5km处与大气模式表现出了较好的一致性,激光能量为100mJ,测量时间约为17min,垂直分辨率为7.5m;2.5km处信号随机起伏引起的统计误差达到1K,可以对边界层内2.5km以下的大气温度进行高精度测量;如果要使测量的高度进一步增加,可以增大激光脉冲的能量或选用口径大的望远镜。这对探测边界层大气温度的转动喇曼激光雷达系统的研制提供了有益的指导。     

利用 IASI资料反演平流层大气温度

红外大气探测干涉分光仪(Infrared Atmospheric Sounding Interferometer, IASI)能够获取平流层的大气温度廓线,而且由其 提取的大气温度扰动信息可用于平流层的重力波特征分析。基于神经网络方法,利用典型 大气廓线库和大气辐射传输模式建立了由IASI反演25～60 km高度范围内的平流层大气温度廓 线的算式,并结合再分析资料对反演结果进行了检验。模拟试验结果表明,平流层大气 温度反演的偏差主要在0 K附近且不超过1 K,均方根误差处在2～6 K之间,且50～5 hPa之间的均方 根误差在3 K以内。对比验证结果表明,本文的平流层大气温度反演与欧洲中期天气预报中心(European Centre for Medium-range Weather Forecasts, ECMWF)的再分析资料在总体上具有可比性,而且反演速度更快,覆盖的区域更完整。     

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.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.