用于原子干涉仪的光学锁相环系统

研制了一种用于原子干涉仪的外差式光学锁相环系统,实现了两台外腔半导体激光器频率和相位的同步,锁相后的激光拍频线宽低于1 Hz,10 MHz积分带宽内的残余相位噪音为0.002 rad2,频偏1~100 kHz范围内的相位噪音达到-100 dBc/Hz。研究了闭环相位噪音对原子干涉仪的影响,当自由演化时间为200 ms、拉曼π脉冲时间为30 μs、单次循环时间为1 s时,锁相后相位噪音对重力测量灵敏度的贡献为10μGal?Hz-1/2     

阿伦方差公式的扩充

阿伦方差是评定振荡器频率随机波动的一个特征值。有人对阿伦方差的引出、推证、表达及其发展已作比较系统的论述。本文对频域参数α作进一步扩充,从而推得一组阿伦方差表达式。     

原子吸收分光光度计的低灵敏度问题

本文分析了原子吸收分光光度计灵敏度低的起因 ,并介绍了相应对策。     

由相位噪声间接测量阿伦方差的研究

振荡器的频率稳定度在时域一般用阿伦方差表征,在频域一般用相位噪声谱密度函数表征,两者存在一定的数学转换关系,即可以由频域测量的相位噪声谱密度函数转换为时域的阿伦方差.t<0.1 ms时短期频率稳定度的时域测量非常困难.利用两者之间的转换关系对振荡器的时域稳定度进行了间接测量,并用实测数据进行了验证.     

如何改善火焰法原子吸收分光光度计的灵敏度

火焰法原子吸收分光光度计灵敏度低是检定中经常碰到一个问题。本文介绍了通过调整喷雾器，提高雾化质量，以及调整灯电流、空心阴极灯位置、狭缝宽度、光束与燃烧的相对位置，吸喷量等方法，达到改善仪器灵敏度的目的。     

基于阿伦方差的微机电陀螺误差建模及其粒子滤波

基于Allan方差对微机电陀螺的随机漂移误差进行分析和建模,并通过粒子滤波提高了微机电陀螺的零偏稳定性.实验结果表明,这种方法比较简单而切实可行,可以明显提高微机电陀螺仪的零偏稳定性.     

医用原子吸收光谱仪灵敏度的测量不确定度评定

目的:为制定JJF (川) 163-2020《原子吸收多元素分析仪(医用)校准规范》,必须对医用原子吸收光谱仪的灵敏度评定测量不确定度。方法:建立了医用原子吸收光谱仪灵敏度的测量模型,建立了校准方法,分析了不确定度的来源,并分别评定了火焰原子化器和石墨炉原子化器的铜,锌,钙,镁,铁,钾,钠,铅和镉的不确定度。结果:铁元素的不确定度U=0. 004,其它元素的U=0. 003,k=2。结论:为医用原子吸收光谱仪评定灵敏度的测量不确定度,可以为编制医用原子吸收光谱仪的校准规范提供技术支持,并有着重要意义。     

工程化原子重力仪综述

基于冷原子干涉原理的绝对重力加速度测量装置具有灵敏度高、可长期测量等优点,在基础物理研究以及资源勘探、惯性导航等领域具有十分重要的意义,是公认的下一代绝对重力仪.本文描述了原子干涉重力测量的原理,总结了硬件系统组成和性能要求,指出了限制测量精度和工程化应用的主要因素,并综述了原子重力仪工程化发展的现状和趋势.     

双平板剪切干涉仪及其干涉图的数值分析

一种用于光学器件及光学成像系统波面差及像质检验的横向剪切干涉仪及其干涉图的数值分析方法,在平行平板横向剪切干涉原理的基础上,分析讨论了改进后的双剪切干涉仪的工作方式及优越性,在对其干涉图的数值分析方法,利用Ｚernike圆正交多项式作为基底函数,对被测光学系统的剪切干涉图进行波面的二维最小二乘拟合,以期重构原始波面,得到被测光学系统的波面差函数,进而不得系统的光学传递函数（ＯＴＦ）,对一组标准镜头进行的测试分析表测量的不确定度＜０．０５。     

光纤非本征法布里-玻罗传感器兰姆波检测灵敏度分析

基于兰姆波的结构工况检测技术在评估复合材料和金属结构的安全性和耐久性方面发挥着重要的作用。作为对传统的压电换能器（PZT）的一种很好的替代,光纤传感器在传感方面的应用正被广泛地挖掘出来,包括兰姆波检测。本文从理论上建立了超声兰姆波作用下光纤非本征法布里．玻罗（EFPI）传感器参数与其输出性能之间的关系。数值结果显示了传感器的性能与其相对于声源的方向角以及传感器的计量长度与超声波长的比值相关。所得出的结论对于EFPI传感器精确地探测兰姆波提供了理论依据。     

Universal properties of kernel functions for probabilistic sensitivity analysis

Development of probabilistic sensitivities is frequently considered an essential component of a probabilistic analysis and often critical towards understanding the physical mechanisms underlying failure and modifying the design to mitigate and manage risk. One useful sensitivity is the partial derivative of the probability-of-failure and/or the system response with respect to the parameters of the independent input random variables. Calculation of these partial derivatives has been established in terms of an expected value operation (sometimes called the score function or likelihood ratio method). The partial derivatives can be computed with typically insignificant additional computational cost given the failure samples and kernel functions — which are the partial derivatives of the log of the probability density function (PDF) with respect to the parameters of the distribution. The formulation is general such that any sampling method can be used for the computation such as Monte Carlo, importance sampling, Latin hypercube, etc. In this paper, useful universal properties of the kernel functions that must be satisfied for all two parameter independent distributions are derived. These properties are then used to develop distribution-free analytical expressions of the partial derivatives of the response moments (mean and standard deviation) with respect to the PDF parameters for linear and quadratic response functions. These universal properties can be used to facilitate development and verification of the required kernel functions and to develop an improved understanding of the model for design considerations.     

不确定条件下复合材料结构的全局灵敏度分析

基于不确定条件下结构的全局灵敏度分析理论,研究了输入变量的不确定性对复合材料结构输出响应量方差和失效概率的影响。考虑材料力学性能、铺设角、铺层厚度及加载载荷的不确定性,利用基于方差和基于失效概率的全局灵敏度分析方法,对复合材料结构输出位移和强度比的不确定性来源进行分析,得到输入变量的全局灵敏度排序结果。对复合材料工字梁结构进行算例分析,验证了所得排序结果的有效性,为工程实际中复合材料结构稳定性优化设计提供了一定的指导。     

Polarization phase shifting cyclic interferometer for surface profilometry of non-birefringent phase samples

A rectangular path cyclic interferometer has the unique property that the counter-propagating wavefronts travelling in the interferometer arms are folded with respect to each other in the plane of the interferometer although the two wavefronts finally emerge from the interferometer unfolded. A phase disturbance introduced in one lateral half of the interferometer arm is therefore manifested in complementary lateral halves of the observed interference pattern. This phenomenon is utilized to evaluate the surface profile of a reflecting sample placed on one of the interferometer mirrors. The sample phase is retrieved using polarization phase shifting. Experimental results showing three-dimensional surface morphology of a small scale integrated circuitry directly etched on silicon are presented.     

马赫-曾德尔干涉仪对大气后向散射的谱分析

论证了马赫-曾德尔干涉仪对532 nm/354.7 nm大气后向散射的频谱分析性能。马赫-曾德尔干涉仪接收激光大气后向散射回波,通过测量双臂光路、正交偏振、四通道结构形成的干涉相位差和干涉对比度,计算大气的多普勒频移,以及大气气溶胶后向散射与气体分子后向散射的比值;发射脉冲激光器及其倍频器可以直接工作在多纵模状态下,大气的后向散射的频谱分析器可以不必与发射光中心频率锁定;给出同时探测大气的后向散射比分布廓线及大气风速的分析方法。马赫-曾德尔干涉仪作为大气后向散射的频谱分析器,若应用于高光谱分辨率激光雷达中,将成为一个性能优秀、前景广阔的大气分析装置。     

Global sensitivity analysis for calculating the contribution of genetic parameters to the variance of crop model prediction

Dynamic models are often used to predict the effects of farmers’ practices on crop yield, crop quality, and environment. These models usually include many parameters that must be estimated from experimental data before practical use. Parameter estimation is a difficult problem especially when some of the parameters vary across genotypes. These genetic parameters may be estimated from plant breeding experiments but this is very costly and requires a lot of experimental work. Moreover, some of the genetic parameters may account for only a very small part of the output variance and, so, do not deserve an accurate determination. This paper shows how methods of global sensitivity analysis can be used to evaluate the contributions of the genetic parameters to the variance of model prediction. Two methods are applied to a complex crop model for estimating the sensitivity indices associated to 13 genetic parameters. The results show that only five genetic parameters have a significant effect on crop yield and grain quality.     

The use of the Allan transformation to analyze the maximum performance of voltage standards and comparators

The problems involved when using the Allan transformation to investigate precision comparators and standards of dc voltage are considered. An approach to determining the parameters is proposed, which enables the maximum performance of the measuring instruments used to be estimated. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 49–52, June, 2006.     

考虑多分量气动导纳的抖振响应敏感性

对于类流线型箱梁桥梁断面,采用抖振频域分析方法和气动弹性节段模型测振风洞试验,初步验证了互谱法识别的多分量气动导纳函数结果的正确性和工程适用性。结合可靠度理论敏感性算法,系统评价了来流风速参数、模型参数、静风力系数、导纳函数和颤振导数等对于二维节段模型抖振响应的贡献率分布关系,更正了工程应用中采用单一分量导纳函数假定带来的对抖振气动力表达式认识上偏差。