双棱镜干涉中虚光源的测量方法对实验的影响简

采用两种不同的方法分别测量了双光束干涉法中两个虚光源之间的距离,并对两种方法对实验结果的误差影响进行了比较分析,分析表明两种方法各有优劣,分别适合不同类型的学生。     

非零位检测凸非球面反射镜的研究

在简要总结各种检测凸非球面方法优缺点的基础上,提出了利用部分补偿法和子孔径拼接干涉检测凸非球面的新方法。分别研究和分析了这两种非零位检测非球面方法的基本原理和基础理论;设计并制作了部分补偿器件,并对其系统误差进行了标定;开发了综合优化和误差均化的子孔径拼接算法;设计并研制了两种方法都适用的检测装置。并结合实例对一口径为130 mm的碳化硅凸非球面分别进行了部分补偿检测和子孔径拼接测量,这两种方法测量所得的全口径面形分布是一致的,其PV值和RMS值的偏差仅为0.010 和 0.002 (=0.632 8 m)。从而提供了两种非零位补偿测试凸非球面的手段。     

透明体的光学定量测量

综述了使用光学方法测量透明体的方法。介绍了两种常用的光学方法——相衬法和微分干涉相衬法。在 2 0世纪 80年代 ,一般认为相衬法和微分干涉相衬法只适用于定性观察而不能实现定量测量 ,主要是因为在其成像原理中的非线性因素的影响。但是对于微分干涉相衬法 ,最近国内外出现了几种定量测量的方法 ,本文对这几种方法进行了总结和比较。     

电寻址空间光调制器“黑栅”效应的消除方法

提出了两种消除电寻址空间光调制器由于低开口率所引起的"黑栅"效应的方法:利用衍射微透镜阵列的方法和利用纯相位型光束整形器件阵列的方法.分析了这两种方法的基本原理,给出了微透镜阵列和光束整形器件阵列的设计思想,并比较了这两种方法的异同点.采用杨一顾相位恢复算法得到了光束整形结果.理论分析及仿真计算表明:这种方法均能有效地消除电寻址空间光调制器相邻象素之间的黑带.     

等离子体诊断中的Abel逆变换

本文描述了两种最常用的Abel逆变换方法,并用这两种方法对不同类型的分布曲线在计算机上进行了模拟计算;研究了输入数据的随机误差、诊断设备的系统误差以及采样点的数目等对Ab-el逆变换精度的影响,同时对这两种方法进行了比较。     

全光网络的攻击与检测方法研究

全光网络是未来信息网的核心。人们在对其优越性能进行研究的同时发现它存在安全上的隐患。针对全光网络普遍采用的物理结构,分析了全光网络的主要攻击类型和检测方法,提出了两种新的检测方法,并与传统检测方法进行了比较。     

激光推进冲量耦合系数测量方法比较

 针对测量冲量耦合系数的水平导轨法和冲击摆法,分别进行了误差计算和实验研究。计算结果表明:水平导轨测量法的相对误差（4.6%）略小于冲击摆测量法的相对误差（6.1%）,其中位移参数和最大摆角的测量精度对于相对误差的影响最大。实验结果表明:两种方法的测量结果基本一致,冲量耦合系数均随着入射脉冲能量的增大而增大,且两组数据相差在6%以内,在入射脉冲能量为3~14 J时,冲量耦合系数最高可达260 N·MW^-1。     

Bending and acoustic waves in a water-filled box studied by pulsed TV holography and LDV

Pulsed TV holography and laser Doppler vibrometry (LDV) are non-destructive and non-contacting methods useful in the testing of mechanical properties in a wall separating two media. This paper presents comparative studies of transient, propagating bending waves in an impact-loaded thin aluminium wall of a box, and acoustic waves generated in the water inside the box using the two mentioned methods. Besides being evaluated and compared, the results were used to investigate qualities of the methods for the specific applications. The measured wave propagations obtained from the two methods are consistent regarding both amplitude and phase. Further, transient pressure fields in the water have been computed from the pulsed TV holography measurements. Since none of the two methods are capable of providing both temporal and spatial information simultaneously, they complement each other.     

Das Größenspektrum des natürlichen atmosphärischen Aerosols

The size distribution of natural occuring aerosol particles with a radius between 10^?5 and 10^?6cm was measured simultaneously by two different methods: Firstly the measurement of the current, caused by the natural distribution of electric charges on the particles, which move along the axis of a cylindrical condenser; secondly the distribution of thoron decay products on the size spectrum of the aerosol. The both methods have their maximum sensitivity in different regions of the size spectrum. The distributions obtained with the two methods are in rather good agreement. The small deviation of the two spectra is ascribed to systematic differences of the measuring methods.     

两种不同前处理方法测定山茶油中的痕量铜

采用湿法消解和萃取法两种不同的前处理方法,石墨炉原子吸收光谱法测定山茶油中精炼油和毛油中痕量的铜,结果表明:两种方法有较好的一致性,湿法消解在精密度上要优于萃取法,萃取法较湿法消解耗时短,试剂消耗少。两种方法的回收率在82.5%—114.5%之间,湿法消解的检出限为0.0134μg/g,萃取法的检出限为0.0160μg/g。     

Self-consistent field method and non-self-consistent field method for calculating the positron lifetime

Many methods are used to calculate the positron lifetime,these methods could be divided into two main types.The first method is atomic superposition approximation method and the second one is the so called energy band calculation method.They are also known as the non-self-consistent field method and self-consistent field method respectively.In this paper,we first introduce the two basic methods and then,we take Si as an example and give our calculation results,these results coincide with our latest experimental results,finally,we discuss the advantages and disadvantages of the two methods.     

线阵CCD相机细分采样成像的像质研究

从理论上推导了线阵CCD相机间歇细分采样和连续细分采样成像所得到的光电图像调制度和调制传递函数公式,并讨论了这两种采样方法对提高动态成像调制传递函数的不同效果,分析比较了它们的特点和工程应用的可能性.     

高温超导滤波器两种刻蚀方法的研究

在高温超导滤波器的制备过程中,针对所使用的高温超导薄膜的特点,采用了两种刻蚀方法——湿化学刻蚀法和离子束刻蚀法,设计对比了两种刻蚀的制作流程及其优缺点,并用两种方法分别制备了高温超导滤波器,对微波特性做了对比分析。得出离子束刻蚀对超导薄膜的性能影响要小一些,用此方法制备的高温超导滤波器具有更好的微波特性。     

First and second fluctuation-dissipation-theorem in electromagnetic fluctuation theory

In electromagnetic fluctuation theory two methods are frequently used: (i) linear response theory and fluctuation-dissipation-theorem, (ii) Langevin-theory. In this note the two methods are compared. The equivalence of both methods is shown. An extension of the second method to describe dynamical processes (radiative heat transfer) in inhomogeneous systems cannot be justified rigorously.     

Speckle intensity mean value dependence on the number of scatterers

The number of scatterers contributing to the speckle amplitude can be determined by the spot size of the incident light or by the amplitude point spread function of the optical system. The speckle intensity mean value measurement results with two methods of choosing the number of scatterers applied are presented. The values of the rms phase deviation and correlation length obtained from two methods agree well. The properties of both methods are discussed. The possibilities for the roughness measurement are suggested.     

动力破碎的几何统计和分形方法

 介绍了物体动力破碎后碎块大小分布的二种统计方法，一为应用Grady和Kipp推广证明的Mott公式，另一为分形。文中证明了二者的一致性，并从前者导得了后者，并解释了它们的物理实质。     

Regularizing a vortex sheet near a separation point

Current methods for computing vortex sheet separation use a regularization parameter which is discontinuous from the body to the vortex sheet. We propose two methods for reducing the errors associated with the discontinuity and improving convergence with respect to the regularization parameter. The “velocity smoothing” method is the simpler of the two, and removes the discontinuity in regularization from one of the two equations where it occurs. The “tapered smoothing” method removes the discontinuity from both equations. In a model problem, both methods are found to converge much more rapidly (with exponents 3/2 and 2 versus 1/2 for the standard method) as the regularization parameter tends to zero. Unsteady algorithms are proposed for evolving the free sheet using the two methods, and are tested in a benchmark problem. Accuracy is significantly improved for similar computational expense.     

Scattering of gaussian beam by a ferrite cylinder

The scattering of a Gaussian beam by a ferrite cylinder is analyzed using two methods. The spatial pictures in the amplitude of the total Gaussian beam near the cylinder resulting from the two methods are both clarified and compared. The scattering by a ferrite cylinder coating a dielectric sleeve is also presented.     

弹道跟踪数据处理方法研究

测量多弹道要求对飞行弹丸进行跟踪,利用卡耳曼滤波方法和最小二来外推方法都能达到跟踪滤波的目的.本文分别推导出用这两种方法滤波的方程,并通过仿真对二者的效果进行比较.     

Measurement of textile materials thermal properties

The determination of thermal properties of textile materials is difficult and subject to errors. Here we used two experimental methods. A PhotoPyroElectric method (Front PPE configuration with a modulated heat flow imposed on the surface of the sensor) and a commercial device (Alambeta) based the hot plate method. Two theorical approaches for the latter device were used. We tested the two methods on different textile materials (cotton, modal, wool and spacer). We observe good agreement between thermal conductivities measured with the two methods.