数字散斑干涉测量流体温度场中的图象处理方法

本文介绍了一种适用于数字散斑干涉测量流体温度场的计算机图象处理方法，主要介绍了以傅立叶变换为基础的低通滤波法在去除散斑图象噪声中的应用，从而提高了散斑干涉图的信噪比，获得了与光学干涉相似的干涉图象。将此法运用于酒精灯火焰散斑干涉图的后续处理上，取得了较好的效果，具有较高的运行效率。     

流体温度场测量中的电子散斑干涉技术

电子散斑干涉是一种利用全电子记录和计算机图象处理系统替代传统照相干版进行测量的先进技术。本文在简要介绍其应用于流体温度场测量的理论与实验的基础上,着重描述了如何通过调整光学系统参数配置来获取最佳质量原始干涉图象的途径,并给出对比分析结果。     

基于双频光栅的微分干涉相衬方法

针对传统微分干涉相衬技术对双折射性物体成像会有伪像的问题,用双频闪耀光栅取代传统微分干涉相衬的分光元件诺曼斯基棱镜,设计了一种微分干涉相衬方法.对双频闪耀光栅设计,模拟入射平面波通过它之后的光强分布,结果表明它能产生两束剪切角很小的光.用双频光栅微分干涉相衬方法对纯相位样品模拟成像,仿真结果和物体的相位轮廓一致.分析了...     

微流体衍射相位显微成像及其在寄生虫测量中的应用

本文提出了一种将衍射相位显微技术与微流体芯片相结合的方法对水源性寄生虫进行定量测量。结合干涉技术与光学显微镜搭建了衍射相位显微成像系统,实现对寄生虫的高灵敏度实时测量。基于光刻工艺,设计和制作了U型捕获结构双层微流体芯片,实现高通量的单个寄生虫捕获。将与聚二甲基硅氧烷(PDMS)折射率相同的聚蔗糖水溶液通入微腔,消除U型捕获结构边缘衍射在相位成像时产生的显著干扰噪声。利用不同直径的标准聚苯乙烯微球验证了该系统的准确性,最大相位值误差不超过3%。采用上述系统测量了100个贾第鞭毛虫包囊和100个隐孢子虫卵囊,然后从干涉图中重构出两虫的相位图。通过对定量相位图的分析得出两虫的形态学参数与定量的光体积差分布,定量的数据为了解其生理特性提供了依据。微流体衍射相位显微成像系统结构简单,稳定性好,测量精度高,在对单个微生物进行实时监测和无标记定量研究方面具有巨大的潜力。     

正交双频光栅CCD系统剪切干涉测量二维温度场

以半导体激光器为光源，利用正交双频光栅（ＯＤＦＧ）ＣＣＤ系统剪切干涉对带平板边界的半圆柱体热源的二维温度场进行实时诊断，分析剪切干涉图时，用柱函数系作为拟合基底，给出二维自然对流温度场的定量分布。     

用外差偏振干涉法测量保偏光纤双折射率

提出一种基于半导体激光调频外差干涉原理的保偏光纤双折射率的测量方法，即通过测量由保偏光纤构成的偏振干涉仪输出的外差信号的频率，求得保偏光纤的相对双折射率，此方法具有较高的分辨率和潜在的高精度，以及系统结构简单，无运动部件和非破坏测量等优点。     

光干涉法测量微机械零件变形的研究

介绍了用光干涉法测量微加速度计零件变形的研究。将准直单色光投射入由一玻璃片和被测件之间形成的空气楔中，被测件表面和玻璃片底面反射的光发生干涉，由面阵CCD接收。用快速傅立叶变换（FFT）图像处理方法得到被测微悬臂梁的三维形变图。该方法可对微小器件的微位移作分辨办为10nm的测量，并直观的显示测量结果。     

温度误差修正与微分膨胀系数

提出一种更切合实际的温度误差补偿和修正方法：采用微分膨胀系数代替平均膨胀系数。同时介绍了微分膨胀系数的测量方法及其测量不确定度。     

相移干涉显微镜中移相误差分析

本文具体分析了影响移相误差的多种因素，比较了在不同移相术中移相误差量对检测精度的影响，从而论证了五步移相术的合理性和利用压电陶瓷微位移传感器的现有定位精度实现０．１ｎｍ级检测精度的可行性。文中还给出了有关的数值计算结果和测试结果，并就有关问题进行了讨论。     

激光全息干涉层析技术测量温度场的探讨

本文介绍了一种激光全息干涉层析技术来测量温度场的方法，具体包括光学质量、数学重建及可视化处理三个方面，并给出了应用实例，对该研究的实际应用给予了验证，结果良好。     

Errors in the DTA and DSC measurement of crystallization interface temperature

Calculations of crystallization kinetics from amorphous specimens by the DTA and DSC type one thermocouple measurement may be somewhat erroneous when performed by conventional techniques. This error arises due to a temperature difference between the measured and the actual interface temperature. The magnitude of this difference depending on where the thermocouple is placed is proportional to the crystal growth rate, heat of fusion and is inversely proportional to the thermal conductivity of the sample and the heat transfer coefficient. It is possible to describe a dimensionless term that estimates the magnitude of this error for various materials.     

Errors of temperature measurement with multiband infrared systems

A model of the errors of temperature measurement with multiband systems was developed. Calculations of these errors for some measurement conditions and systems were carried out. It was shown that multiband systems are capable of producing accurate results of noncontact temperature measurement only in a limited number of applications and that to have small internal errors, they must be designed and built with much greater care than in the case of typical single-band systems.     

干扰吸收峰影响下TDLAS温度测量方法研究

固体飞秒激光器以其体积小、成本低、使用寿命长、稳定性高、技术较为成熟等特点,受到市场的广泛青睐。重复频率是飞秒激光器的一个重要参数,在实际应用中,高重复频率能带来高效率、高精度等诸多重要优势。本文介绍了SESAM锁模、KLM锁模、高次谐波锁模等常用的GHz固体飞秒激光器锁模技术及发展情况,阐述了GHz飞秒光源在激光加工、距离测量、光谱测量等应用场景中突出的性能优势,并对GHz重复频率固体飞秒激光技术的发展方向进行了预测,为推动GHz重复频率固体激光器技术的完善与提升提供借鉴。     

Errors in dynamic force measurement

Loadcells for materials testing machines are calibrated statically by comparison with a transfer standard, traceable to the National Physical Laboratory. There is evidence to suggest that, under certain conditions, this static calibration may be insufficient for dynamic testing. The possibility of an error being generated by the inertia of the mass between the loadcell and the specimen is discussed and the results of experiments to measure this error are presented. For the case chosen it is shown that the inertia error may be predicted by calculation. Errors may also arise from the method of dynamic force measurement. The conventional DVM and the analogue peak hold voltmeter are widely used but are subject to errors in a practical machine situation due to their method of operation. Bandwidth limitations are also illustrated for a number of instruments with different sampling rates. A better, although more expensive and complicated solution is to digitise the signal and to use some form of spectral analysis such as the Fast Fourier Transform or the Cross Correlation Integral. The theory for the latter is presented and its merits discussed.     

Errors in film refractive-index determinations from interference fringes

An analysis of interference fringes (channel spectra) in transmission or reflection spectroscopy of optical films can provide an accurate method for determining the refractive index or thickness of the film. If the index is changing and the common equation n = 1/(2tΔv) determined from the positions of two adjacent maxima in the interference pattern is employed, the resulting refractive index does not lie between the correct values at the frequencies of the two maxima as intuitively expected but well outside this range. This error can be large and is not restricted to the previously discussed case of an index with a linear dependence on wavelength.     

基于双热电偶的瞬态流体温度测试方法研究

针对目前航空发动机空气系统瞬态温度测试频响的需求,提出一种基于双热电偶的瞬态流体温度测试方法。该方法利用两个结点大小相同但材料不同的热电偶测量流体同一空间点的温度,并基于集总参数法反推出流体真实温度,并给出考虑误差的后处理算法。基于固体导热数值计算,验证此方法的可行性及相关后处理方法的可用性。采用双热电偶装置,对管道流动温度变化进行测量,基于微细热电偶的测量结果标定两支热电偶的物性参数比,应用后处理程序实现流体温度的反推。试验结果表明:标定段的反推流体温度平均测量误差率为0.52%,校验段的反推流体温度平均测量误差率为1.6%,反推流体温度的响应速度与微细热电偶响应速度相当。