共查询到20条相似文献,搜索用时 46 毫秒
1.
以单束正交线偏振光为光源,利用角向偏振显示器,采用CCD摄像机进行图像采集,利用Matlab软件进行图像处理,设计了一种由He-Ne激光器、角向偏振显示器组成的偏振光偏振方向显示系统,并研究了其角度特性.实验结果表明:系统在起偏器的起偏角分别为0°、90°、180°、270°、360°时,角向偏振显示器偏振显示角度的测量准确度分别为0.480°、0.168°、0.528°、0.421°、0.340°,测量精确度分别为0.208°、0.576°、0.660°、0.603°、0.466°,测量数据拟合曲线的线性相关系数为0.999.结合1/4波片,检偏器和分光比为50:50的分束器,构建了椭圆偏振光测量系统,完成了椭圆偏振光测量实验,椭圆率为0.198. 相似文献
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A Novel Method to Calculate the Initial Phase Difference between the Two Fibre Arms of Laser Homodyne Iuterferometer
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We suggest a novel method to calculate the initial phase difference between two fibre arms of a laser homodyne interferometer. Put the two fibre arms in a temperature controller, whose short term stability is 0.02° C (measured in an hour), then measure the interference photocurrent and the photocurrents from the two fibre arms at a fixed temperature. With these three photocurrents we can calculate the value of the initial phase difference. We set up a simple laser homodyne interferometer to test the theory. The experimental results are repeatable and the measurement precision is about 0.04°. It is theoretically and experimentally proven that this method is potentially easy and practical. 相似文献
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R. Michaels 《Hyperfine Interactions》2011,201(1-3):25-29
The Lead Radius Experiment PREX will run in Spring of 2010. The experiment measures the parity-violating asymmetry in the elastic scattering of polarized electrons from a lead nucleus at an energy of 1.05 GeV and a scattering angle of 5°. The Z 0 boson couples mainly to neutrons, and provides a clean measurement of R n with a projected experimental precision of ±1%. The measurement is a fundamental test of nuclear theory and pins down the density-dependence of the symmetry energy of neutron rich nuclear matter which has impacts on neutron star structure, heavy ion collisions, and atomic parity violation experiments. Recent developments in the experiment are described. 相似文献
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超宽带(UWB)冲激雷达目标探测中时域天线阵列波束延时控制扫描是通过天线阵列单元间精确的延时控制实现的。在介绍UWB时域波束延时控制扫描原理的基础上,研制了用于UWB天线时域波束扫描的延时控制器,其延时步进为50 ps,延时精度可达10 ps。利用该延时控制器对单元间距42 cm的4单元UWB天线阵列H面方向进行了单元间延时控制波束扫描测量,扫描步进角度小于2°。结果显示,在0°,10°,20°和30°扫描时,实际扫描角度分别为-0.5°,10.5°,20°和29.5°,与理论计算值之间误差小于1°。 相似文献
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介绍了电光采样法测量电子束束团长度的实验原理和装置,理论分析并模拟计算了被测电子束团库仑场分布、ZnTe晶体的电光效应与束团电场的关系,并利用琼斯矩阵法分析了探测光通过电光晶体时在束团电场作用下的偏振变化、测量信号与束团长度的关系等。分析表明:测量中应使束团库仑场垂直于ZnTe的[001]方向,探测光偏振方向与ZnTe晶体y″轴成45°或者135°夹角,1/4波片快轴与探测光偏振方向夹角应取45°,这时平衡探测器输出信号与束团库仑场Eb成正比。1/4波片的作用是将电光晶体的工作点从非线性段移到线性段,平衡探测的作用是简化信号与Eb的关系,并提高信噪比。为实际测量应用提供参考。 相似文献
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The paper describes the determination of melting pressure of mercury around 0°C using the volume method at the National Physical
Laboratory. Also described are the details of the experimental set-up and the estimation of the uncertainty in the measurement
of pressure. The equilibrium pressure in the flat region of the melting curve over which bulk transformation occurs, is established
by increasing/decreasing the pressure. The scatter in the obtained data for equilibrium pressures is within the limit of experimental
uncertainty of the measurement of pressure. The average observed value for the melting pressure of mercury at 0·002°C is 756·93±0·25
MPa agreeing well with the reported value of Dadsonet al [1] and Molinaret al [2a, b]. 相似文献
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《中国物理 B》2021,30(10):106801-106801
A theoretical model based on energy conversation is constructed to characterize the contracting behavior of the nonconductive droplet actuated by the dielectric effect in an immiscible dielectric liquid. To verify the theory, COMSOL is employed to simulate the evolution of the droplet based on dielectrowetting, and a measurement platform is established to monitor the change process of the droplet profile. The contact angle and the height of the droplet increase linearly up to 48° and 2.03 mm respectively when U ranges from 55 V to 160 V, while the droplet remained stationary when U 55 V.The relative experimental results coincide with the prediction of theory and the simulation analysis. 相似文献
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The differential absorption method with the conventional CO2 laser is discussed for the detection and monitoring of ozone in ambient atmosphere. By using the P(14) line in the (00°1 to 02°0) and the R(16) line in the (00°1 to 10°0) band, the measurement of ozone was made in a field. As an experimental result, the minimum detectable concentration of 0.15 ppm was obtained with the system, and the concentration of 0.2 ppm was measured in a photo-chemical smog. 相似文献
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A method is proposed for an experimental determination of the equilibrium condensate fraction in He4II which relies only on measurement of the liquid structure factor as a function of temperature. Existing data at 0.79°K and 1.4°K indicate the value to be about 10%. 相似文献
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Some years ago we developed an automatized reflectometric method to measure the surface azimuthal anchoring energy of nematic
liquid crystals on an optically isotropic substrate. This method provides a high accuracy and sensitivity but requires the
use of wedge glass plates and a sufficiently high anisotropy of the intensity reflectivity coefficients. This latter condition
restricts greatly the number of possible substrates that can be investigated with this technique. Here we develop a new reflectometric
method which offers comparable or better accuracy and sensitivity but does not require wedge plates and high anisotropy of
the reflectivity coefficients. The method is fully automated and provides a direct measurement of the azimuthal director angle.
The experimental procedure exploits the dependence of the reflectivity tensor on the surface director orientation. The measurement
of the azimuthal angle does not require any knowledge of the optical parameters of the nematic material and of the optically
isotropic substrate, and provides an absolute accuracy better than 0.2° in the whole range 0-360° and a sensitivity better than 0.1°. This reflectometric method can be also used with weakly anisotropic substrates as well as thin rubbed polymeric layers.
In this latter case, the effective uncertainty in the measurement of the director azimuthal angle depends on the substrate
anisotropy. A simple and direct experimental procedure to estimate this uncertainty is proposed.
Received 8 January 2002 and Received in final form 27 February 2003 / Published online: 15 April 2003
RID="a"
ID="a"e-mail: faetti@df.unipi.it 相似文献
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针对捷联惯导温度补偿的研究,设计了一种用铂电阻Pt1000作温度敏感器, ADS1148为信号调理和A/D转换的高精度双通道数字测温系统。采用高性能集成芯片、双恒流源式三线式配线法、比例输出结构和RC低通滤波器的设计,有效的简化了电路,增加了系统的抗干扰能力并减小了硬件误差;主控芯片采用MSP430单片机实现与ADS1148的通信和对上位机输出与温度数据相对应的16位数字量。试验结果表明该系统在捷联惯导温度补偿研究中所用的-40°C到60°C的温度范围内达到了0.002°C的分辨率。 相似文献
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《Heat Recovery Systems and CHP》1992,12(2):113-121
A method has been developed for the combined measurement of thermal conductivity and diffusivity. The proposed method is based on an extension of the transient probe theory. The developed technique, the differential sensor method, is then used here for the measurement of thermal conductivity and diffusivity of glycerin, dry and moist porous materials in the temperature range of –20 to 80°C. Calculations have been doneby IBM PC/XT using a data fitting program. The effect of water content and temperature on the thermophysical properties has been elucidated in frozen as well as unfrozen states. The experimental results of thermal conductivity and diffusivity obtained by the differential sensor method have been compared with the results of other methods. 相似文献
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A simple ab initio pair function model is used to determine the equilibrium bond angle in the water molecule. The calculated equilibrium bond angle is 104·27° compared with an experimental value of 104·45°. Quantitative support is obtained for the qualitative valence shell electron pair repulsion theory of directed valence. 相似文献
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In this paper, a new optical material application and a heterodyne interferometer are proposed for measuring small angles. In the proposed interferometer, the optical material is a (1 0 0) silicon wafer applied to compose a new architecture of small angle sensor. The small angle measurement used the phase difference which is dependent on the incident angle at the silicon wafer surface to deduce the angular variation. The proposed architecture is simple and uses the common path method to compare test and reference signals; thus, small angles can be easily and accurately measured by estimating the phase difference. The experimental results demonstrate the feasibility of this method. The angular resolution and sensitivity levels superior to 7 × 10?5° (1.3 × 10?6 rad) and 150 (deg/deg), respectively, were attainable in a dynamic range of 0.45°. 相似文献
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根据菲涅尔全内反射相变理论,给出了双菱体λ/4消色差器的结构设计、性能分析和测量方法.由有效通光孔径和光线追迹设计出BK7玻璃在波长532 nm时相位延迟λ/4的双菱体的结构,用作532 nm至1 064 nm波长范围的标准λ/4相位延迟器.理论分析了入射角变化和波长变化对双菱体相位延迟的影响,当入射角变化限制在±4.3°以内时,其影响得到补偿;波长从532 nm到1 064 nm产生的误差为-0.65°.采用椭偏法中的消光技术,分别实测了双菱体在532 nm和1 064 nm波长下的相位延迟为:90.08±0.14°和88.99±0.1°,可知两不同波长产生的相位延迟误差为-1.09°. 相似文献
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A Raghava Rao SS Ramana Reddy K Premchand K L Narasimham K Parthasaradhi V Lakshminarayana 《Pramana》1982,18(3):271-278
The values of incoherent scattering functions are determined experimentally for 145 keV gamma rays in elements Au, Ag and
Y at scattering angles 40°, 70° and 100°, using a x-ray gamma coincidence technique. The corresponding theoretical values
are obtained from the tabulations of Hubbellet al, and computed from the models of Jauch and Rohrlich and Shimizuet al. A comparison between the theoretical and experimental results showed that the non-relativistic approach adopted in the theory
of Shimizuet al is inapplicable to the present cases. A gross agreement is noticed between the present experimental results and the other
theoretical values. 相似文献