面内微位移测量的散斑相位涡旋相关方法研究

提出了用散斑相位涡旋相关方法测量面内微位移。 首先利用拉盖尔-高斯变换, 将光强灰度图的实值信号I(x,y)变为复光强信号(x,y),获得涡 旋分布矩阵;然后,以涡旋 核结构参数的偏心率e作为特征因子进行相关运算;最终实现面内微位移的测量。在相同计 算机配置下,对毛玻璃的面内位移进行了测量,结果显示,散斑相位涡旋相关法的平均计算 时间为35.4ms,传统数字散斑相关法(DSCM)的平均计 算时间为376.7ms,而两者的相对误差均小于5%,这与数值模拟结果 相符。实验结果与数值 模拟结果表明,散斑相位涡旋相关方法可准确测量面内微位移,与传统DSCM相比,在保持相 同测量精度的前提下,计算效率至少提高了1个数量级。     

数字图像相关法散斑图质量评价方法

为了研究数字图像相关方法中散斑图质量的有效评价问题, 采用散斑图质量表征参量——平均灰度2阶导数对散斑图质量进行了有效评价。通过分析图像插值误差与图像灰度信息分布形式之间关系, 指出散斑图平均灰度2阶导数与散斑图灰度信息分布形式之间的关系; 为了验证该散斑图质量表征参量的有效性, 利用傅里叶变换对散斑图进行平移实验, 通过Newton-Raphson(N-R)方法对平移前后的散斑图进行亚像素位移计算, 由位移计算结果可知, 具有低的平均灰度2阶导数的散斑图对应小的位移测量误差。结果表明, 平均灰度2阶导数在散斑图质量评价中具有一定的有效性; 在实际应用中, 应结合散斑图平均灰度2阶导数和平均灰度梯度对散斑图质量进行综合有效的评价。该研究为高质量散斑图的制备与选取提供了参考。     

数字散斑的边缘相关测量法

利用数字激光散斑图像测量物体的形变和微小位移是一种新兴的非接触测量方法,为提高测量速度,通过对数字散斑相关测量方法(DSCM)和激光散斑图像的特点进行研究,提出一种针对数字散斑图像的边缘相关测量法(DSMC)。该方法把移动前后的激光散斑图像像素在单方向上求和,使整幅图像的能量集中在边缘上,然后使用边缘上所形成的一维数列,通过插值和相关的方法求解激光散斑图像的位移。而激光散斑图像的位移可以反映出物体的位移或形变。理论和实验证明了该算法可行,可以大大节省数字散斑相关测量中数据处理的时间而不影响计算精度,因为此算法的运算精度主要取决于插值点的个数和散斑图像自身的综合误差。     

基于数字散斑的弯管残余应力测量系统的误差分析

针对基于数字散斑相关法(DSCM)的残余应力测量系统,分析了影响系统精度的主要误差因素,并根据各个误差因素的形成原理,提出了减少或去除误差的方法。通过实验数据的对比,验证了误差因素对测量系统的影响,同时验证了所给出的减少误差的方法的可行性,为基于数字散斑相关法的测量系统的误差分析提供了有益的参考。     

数字散斑三维重建中散斑特性分析

详细介绍了基于数字散斑相关技术的三维重建方法,包括双目立体视觉基本原理以及散斑三维重建基本流程。重点分析了整像素对应点查找方法以及基于牛顿-拉弗逊迭代的亚像素插值算法,实现了散斑亚像素级三维重建。针对数字散斑相关计算模型,分析了影响相关系数的因素,并围绕相关系数计算和亚像素同名点插值精度两方面重点分析了二值随机散斑和灰度随机散斑的三维重建效果。通过设计不同尺寸颗粒的散斑图案和采用不同大小的相关计算窗口,分别对平面陶瓷板和陶瓷标准球进行了三维重建精度分析。实验结果表明,二值散斑能获得更高的重建精度。     

基于数字散斑相关的封装热机械耦合效应测量

利用数字散斑相关方法(DSCM),对COB封装结构在热循环状态下的表面热机械耦合效应进行了测量.利用CCD摄像机采集封装芯片在不同温度场中的散斑图像,对比采集到的图像,获取封装芯片在温度场作用下的面内变形.根据三角法测量技术原理,将离面位移的测量转化为面内位移的测量,从而获得了芯片受热后的翘曲形变和弹性应变分布.将实验测量与有限元模拟以及理论计算的结果进行了对比,3种结果吻合得比较好,表明了实验方法的有效性和可行性.     

基于微粒子群优化算法的数字散斑图像相关方法

为了能够通过一步搜索同时得到数字散斑图像中所测点的整像素和亚像素位移信息,采用灰度插值的方法构造了亚像素子区,改进了基于微粒子群算法的数字图像散斑相关方法。对含有平移信息的模拟散斑图和具有应变的模拟散斑图进行相关计算,验证了该方法的适用性;在对具有微小面内位移转动的试件进行测量时,比较了整像素的微粒子群算法和不同量级的灰度插值下的亚像素微粒子群算法。结果表明,基于微粒子群算法的亚像素数字散斑图像相关方法在测量小位移方面具有一定的优越性。     

基于梯度法的数字散斑图像相关亚像素搜索算法

数字散斑图像相关法是对全场位移和应变进行测量的十分有用的无损检测技术.设计精确的亚像素搜索算法是提高测量精度的关键问题.研究了数字散斑图像相关技术的基本原理,在梯度法的基础上,提出了一种基于梯度法的变步长的亚像素搜索算法并应用到相关搜索中,通过对模拟散斑图的位移分析证明了该算法的可靠性和稳定性,并对刚体平移实验进行了测...     

亚像素数字散斑相关测量的曲面拟合法研究

研究了亚像素数字散斑相关测量中整像素搜索窗口、拟合窗口、散斑尺寸等因素对曲面拟合法测量精度的影响.采用二元二次多项式曲面拟合方法,利用计算机生成的模拟散斑图像,对水平位移分别为0.1,0.3,0.5,0.7,0.9pixel的图像进行了研究.结果表明,最佳搜索窗口为31×31～51×51 pixels,最佳拟合窗口为3×3 pixels,散斑图的平均散斑尺寸为2 pixel时,能较容易地实现相对误差小于5%的目标.而在高斯噪声免疫力方面,0.9 pixel以上的位移具有较强的免疫力.在散斑相关测量精度要求不是很高(＞1 μm)的情况下,曲面拟合法是一种非常适合的方法.     

基于分形插值的频域散斑相关法面内位移测量

针对传统频域数字散斑相关法在测量物体面内位移测量精度较低的问题,提出一种基于分形插值的频域数字散斑相关法。该方法在频域数字散斑相关法的基础上,引入Hanning窗函数对图像进行滤波处理,克服了图像边缘效应对最终位移值的影响;同时利用散斑图像的子区域与整幅图像在结构形态和灰度特征的自相似性,采用分形插值的方法进行亚像素插值,进而能精确定位相关点,得到更精确的亚像素位移值。实验结果表明:该方法保持了频域散斑相关法的测量速度,且将测量的绝对误差降低在0.01~0.03 pixel以内,并进一步通过刚体平移实验测试了算法的可靠性。     

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.