某型机载武器投放轨迹姿态测量方法研究

某型机载武器飞行试验中,由于测试用摄像机安装位置的特殊性,导致摄像机视场交会区域较小,无法采用常规影像交会测量的方法获取武器投放过程的轨迹、姿态运动参数,针对该问题,设计了一套适用于近距离、大倾角条件下的机载武器投放试验影像测试方案。通过设计90°和120°弯折光路的特殊弯管镜头,转换摄像机安装位置,解决武器投放影像获取问题,通过建立大倾角多摄像机联合计算模型,实现了武器投放轨迹、姿态的测量。实验室仿真实验结果表明,采用该方案轨迹最大测量误差不大于2 cm,满足飞行试验精度要求。     

基于图像的空中加油软管平衡拖曳位置测量方法

针对飞行条件下加油软管平衡拖曳位置的获取难题,设计了一套基于图像的空中加油软管平衡拖曳位置测量方法。通过在加油机上加装多路高清影像测量系统获取空中加油过程软管的运动图像,并对多像机同步采集、大景深像机标定、无参考点加油锥套识别与跟踪等关键技术进行研究,实现了加油软管平衡拖曳位置的精确测量。仿真实验结果表明,采用该方案测量精度优于5 cm,满足飞行试验精度要求。     

用毛细管成像法测量液相扩散系数——等折射率薄层测量方法

本文提出了一种测量液相扩散系数的新方法. 该方法用透明毛细管构成液相扩散池, 利用毛细管成像法特有的折射率空间分辨测量能力, 通过直接观察和记录扩散介质的等折射率薄层在毛细管中的移动规律, 基于扩散过程遵循的Fick第二定律计算出液相扩散系数. 在25 ℃下研究了丙三醇和纯水间的扩散过程, 扩散系数的测量值与全息干涉法的文献报道值之间的相对误差为4.47%, 论文同时分析了折射率测量精度和毛细管管壁黏滞力对扩散系数的影响. 用毛细管成像法测量液相扩散系数具有样品需要量少、测量速度快、系统稳定性好的特点, 为快速测定微量样品的扩散系数提供了一种有效的新方法. 关键词： 扩散系数 液体折射率 毛细管成像法     

微波铁氧体的介电常数和磁导率的测量

本文利用反射式谐振腔,通过测量放入样品前后谐振腔反射系数的变化,确定介电常数虚部ε″和磁导率虚部μ″。研究了样品形状和放在谐振腔不同位置对介电常数和磁导率测量的影响。测量系统有较高的灵敏度。通过提高谐振腔的品质因数和使谐振腔接近临界耦合,并适当减小谐振腔的体积,使系统测量损耗角正切达到10^-5数量级并不困难。     

超声波声速测量方法的探讨

介绍一种测量空气中超声波声速的新方法--改变频率干涉法（也叫改变频率驻波法）.并对实验数据、测量精度进行了分析.     

用偏光干涉法动态测量扭曲向列型液晶指向矢

提出一种基于双折射晶体劈的偏振态实时测量方法,并将该方法用于扭曲向列型液晶透射光的偏振态分析,实现了液晶分子平均指向矢的动态测量.利用基于晶体劈的偏光干涉法将待测光的偏振参量编码为两组干涉条纹,通过对干涉条纹定位实现偏振态的实时测量;再根据液晶指向矢的倾角、扭转角与透射光偏振态之间的关系,推算出液晶分子平均指向矢的动态信息.本实验测量液晶指向矢的速度为每秒5次,液晶平均指向矢的倾角、扭转角的测量准确度达到0.2°.本文研究为液晶分子平均指向矢的动态测量提供了一种有效途径.     

“干涉逼近法”测量液体折射率

提出了一种高精度测量液体折射率的新方法一“干涉逼近法”.这种方法可以在测量过程中监视被测液体温度不均匀性给测量带来的误差.由于受温度测量的限制,其测量液体折射率的不确定度在1×10~(-6)到4×10~(-5)(2σ)之间,具体值取决于液体折射率的温度系数.     

Multidimensionally resolved pore size distributions

A novel method of determining median pore size and pore size distributions as a function of spatial position inside a porous sample is described. Pore sizes have been measured with 1-, 2- and 3-dimensional spatial resolution, using NMR cryoporometry in conjunction with magnetic resonance imaging techniques. The method is suitable for pore diameters in the range of 30 Å to over 2000 Å pore diameter, and is based on the technique of freezing a liquid in the pores and measuring the melting temperature by nuclear magnetic resonance. Since the melting point is depressed for crystals of small size, the melting point depression gives a measurement of pore size.     

Level structure of 22Mg: implications for the 21Na(p,gamma)22Mg astrophysical reaction rate and for the 22Mg Mass

The level structure of (22)Mg has been studied with high-sensitivity gamma-ray spectroscopy techniques. A complete level scheme is derived incorporating all subthreshold states and all levels in the energy region relevant for novae burning. The excitation energy of the most important astrophysical resonance is measured with improved accuracy and found to differ from previous values. Combining the present result with a recent resonance energy measurement of this state leads to a derived (22)Mg mass excess of -400.5(13) keV.     

正交振幅正关联正交位相反关联光束的贝尔态直接测量

提出了一种新的EPR光束关联度直接测量的方法.这种方法可以不用本地光直接测量具有正交振幅正关联、正交位相反关联特性的EPR光束的关联度.然后提出了在这种测量方法基础之上的量子密集编码实验方案.     

Compensating for pulse imperfections in REDOR

Rotational-echo double resonance (REDOR) is a magic-angle spinning technique for measuring heteronuclear dipolar couplings. Rotor-synchronized pi pulses recouple the dipolar interaction. The accuracy of a REDOR determination of distance or orientation depends totally on the quality of the dephased (recoupled) and full-echo spectra. We present a scheme for measuring and compensating for the effects of pulse imperfections in REDOR experiments. No assumptions are made about the quality of the pi pulses, and no pulses are added or taken away in implementing the compensation for incomplete REDOR dephasing by imperfect pi pulses.     

Real-time dual-wavelength digital holographic microscopy based on polarizing separation

We report on a manifold advanced dual-wavelength digital holographic microscopy (DHM) configuration with a real-time measurement capability. The proposed configuration based on a polarizing separation scheme can be used for microscopic imaging polarimetry as well as dual wavelength digital holographic microscopy. In this paper, we show the feasibility of the proposed scheme by conducting the dual wavelength DHM experiments on a sample with a step height of 1.34 μm nominally. An averaging technique is treated and three-dimensional (3D) topographic measurements are presented. The results obtained by the proposed polarization separation based single shot DHM approach shows it can provide a real time solution for measuring 3D profile information of small objects with excellent accuracy.     

电机补偿式焦度仪镜片参数的计算

针对目前市场上测量眼镜片相关参数全自动焦度仪测量范围小、测量精度较差等问题,研制了基于电机补偿原理的焦度仪。该焦度仪采用步进电机带动分划板做线性运动对分划板的位置进行补偿,通过改变焦度仪光学系统的物像关系来提高焦度仪的测量精度,扩大它的测量范围。测量时放入待测镜片,待整个调节过程结束后,电器部件会将每个接收到的图像进行分析计算后取平均值,得到待测镜片的各项参数。利用本样机对一些典型镜片进行了测量,结果显示所有镜片的误差范围均在±0.02 m-1内,表明本文研制的焦度仪完全符合国家计量检定规程的计量检定要求。     

高精度V棱镜折射仪光机结构设计

针对传统V棱镜折射仪采用光学度盘,目视对准方式无法满足现代光学玻璃生产线以及高精度折射率测量的需求。提出一种新型的高精度基于CCD 机器视觉对准的V棱镜折射仪的总体设计方案,并对准直光管、传动机构、锁紧和微调机构以及轴角编码测角机构等主要组成部分进行了光机结构设计。在考虑空气折射率影响因素的修正公式的基础上,分析了仪器的检测误差。实验结果表明:其折射率检测精度可达 310-6,满足了高精度V棱镜折射仪的技术指标要求。     

A mixed method for measuring low-frequency acoustic properties of macromolecular materials

A mixed method for measuring low-frequency acoustic properties of macromolecular materials is presented. The dynamic mechanical parameters of materials are first measured by using Dynamic Mechanical Thermal Apparatus(DMTA) at low frequencies, usually less than 100 Hz; then based on the Principles of Time-Temperature Superposition (TTS), these parameters are extended to the frequency range that acousticians are concerned about, usually from hundreds to thousands of hertz; finally the extended dynamic mechanical parameters are transformed into acoustic parameters with the help of acoustic measurement and inverse analysis. To test the feasibility and accuracy, we measure a kind of rubber sample in DMTA and acquire the basic acoustic parameters of the sample by using this method. While applying the basic parameters to calculating characteristics of the sample in acoustic pipe, a reasonable agreement of sound absorption coefficients is obtained between the calculations and measurements in the acoustic pipe.     

Ultrasonic interferometry for the measurement of shear velocity and attenuation in viscoelastic solids

A method for the measurement of the shear properties of solid viscoelastic materials is presented. The viscoelastic material is cut into a cylindrical sample which is clamped between two rods. The transmission and reflection coefficient spectra of the fundamental torsional mode through the sample are measured by means of two pairs of piezoelectric transducers placed at the free ends of the rod-sample-rod system. Such spectra exhibit maxima and minima which occur approximately at the resonance frequencies of the free viscoelastic cylinder. Therefore, the shear velocity can be obtained by measuring the frequency interval between two consecutive maxima or minima. The shear attenuation is derived by best fitting the analytical expression of the reflection and transmission coefficients to the experimental spectra. The test is very quick to set up as the sample is simply clamped between the two rods.     

微光像增强器积分灵敏度单次测量误差分析

为了提高批量微光像增强器性能参数的测试速度,通常采信单次测试数据作为测量结果。在该情况下,参数单次测量结果的误差将直接决定性能评价结果的准确性。以微光像增强器积分灵敏度的参数测试为例开展单次测量误差评定,通过对微光像增强器积分灵敏度的测试方法、测量装置、数据计算等误差情况进行综合分析,计算得到的积分灵敏度单次测量最大误差为6.7%;在该基础上,提出了采用更高加工精度光阑、对入射光测量位置进行修正以及阶段性辅助参量重复性测量校对的积分灵敏度单次测量误差控制方案。研究结果对微光像增强器批量化快速测试具有重要的指导意义和参考价值。     

光学材料光学不均匀性绝对测量误差分析

绝对测量技术去除了干涉仪参考面面形误差,可实现光学材料光学不均匀性的高精度测量。对现有主要光学材料光学不均匀性绝对检测技术进行了总结比较,针对像素错位、干涉图分辨率、干涉仪测量重复性、样品厚度以及折射率测量等因素对光学不均匀性绝对检测的影响进行了实验分析。实验结果表明:干涉仪重复性是光学不均匀性测量的主要误差。样品翻转测量法、样品直接透射测量法、平行平板样品测量法3种测量方法均可实现光学不均匀性（RMS）10-8检测精度。     

3D coordinate measurement based on inverse photogrammetry and fringe analysis

A method based on inverse photogrammetry and fringe analysis is presented for 3D coordinate measurement. Measurement system mainly consists of a micro-camera fixed on one end of a measuring rod, a measuring probe on the other end and a liquid crystal display screen for displaying 2D fringe pattern in the measurement. In the measurement process, the probe contacts the surface of the measured object, and the CCD camera captures the stripes image on displays screen. The coordinates of camera principal point in the world coordinate system may be determined by the phase information carried in the fringe pattern. The coordinate relations between the principal point of the camera and the measuring probe can be determined with a least square optimization technique in camera coordinate system. This method has the advantage of large measurement range, good flexibility, and portable, which is suitable for field measurement. A result of our method is compared with that of the Coordinate Measuring Machine (CMM), which shows that the measurement accuracy of this method can meet accuracy requirement of the field measurement in large dimension.     

液体电阻率测量装置的设计与制作

针对液体本身物理性质复杂、电阻率难以测量的问题,本文设计了一种新型液体电阻率测量装置.为有效采集被测对象的信息,对容器结构进行了巧妙设计,创新性地实现了石墨电极与容器一体化,提高了测量精度;利用传感技术采集电压、电流信号并将数据传入单片机,经单片机运算后通过液晶屏实时显示电阻率,具有快捷、准确测量的优点,在教学科研方面有一定实用价值.