“测量单缝衍射的光强分布”实验中值得注意的一个问题

在做普物光学实验——夫朗和费单缝衍射光强分布测量时,一些书主张:感知光强的光电管在移动中“每隔1 mm 取一数据”(光电流值),然后作出光强分布图象,并与理论值比较,……。可是我们知道,单缝衍射的实际或理论花样,其光强分布曲线的极值点——极大值点(主最大和各次最大亮条纹处)和极小值点(各最小暗条纹处)——不可能都恰巧分     

基于两步成像的单缝衍射自动测量

建立基于两步成像的单缝衍射自动测量系统,用CCD连续采集成像于旋转白屏的单缝衍射图像,通过衍射图像的平均消除激光散斑的影响;通过分别对零级和非零级条纹成像,解决CCD动态范围较小的问题;用图像处理方法进行条纹水平矫正、极小值位置自动判读,实现单缝宽度自动测量功能.用此系统进行了单缝衍射条纹光强分布及单缝宽度的自动测量实验,相对偏差在2%以内.     

光的干涉和衍射的Matlab数值模拟

利用Matlab数值模拟杨氏双缝干涉、单缝衍射和光栅衍射的图案和光强分布曲线,并讨论了光的非单色性对干涉条纹的影响.     

激光单缝衍射测量实验的两点改进

分析了目前激光单缝衍射光强分布测量中存在的问题,给出了两点改进的测量方法:一点测量技术上的改进和一点实验仪器上的改进更新。用改进后的实验仪器较好地测量得到各级明条纹的光强分布。实验测量结果与夫琅和费衍射理论模拟结果吻合较好。     

单缝衍射自动测量系统的研究

单缝衍射自动测量系统以单片机AT89S52为控制核心,控制步进电机带动光电池逐点测量衍射条纹光强,再通过串口把测量数据传给计算机处理、显示,减小了人工测量中由于移动光电池,或在读数、计算时出现的误差,达到比传统实验方法更高的精度,并可以节省大量的测量、计算工作量,实现单缝衍射实验的数据采集、计算处理自动化.     

光学实验中应用锁相放大技术的初步探索

使用 WD5光电接收器对“单缝衍射相对光强分布”的测量,得到良好的效果。在高级次衍射条纹的测量中分析了 WD5光电接收器检测的光强比使用传统的测量手段至少提高了3个数量级。实验结果证实了在光学实验中应用锁相放大技术是提高检测灵敏度的有效方法。     

夫琅禾费单缝衍射实验的仿真研究

根据夫琅禾费单缝衍射理论,应用MATLAB软件编程,对衍射过程进行仿真,作出单缝衍射光强分布图形,通过改变光的波长、入射方向、缝宽和焦距,观察到单缝衍射光强分布的变化规律.     

单缝衍射光强分布测试法的研究

单缝衍射光强分布测试法的研究吴银花，王引娣（西北师范大学）单缝衍射光强分布实验中测量误差偏大是较棘手的问题，为此我们做了一些探讨性的研究工作．１误差原因分析１．１实验原理夫琅和费单缝衍射花样在空间某定点Ｐ（图１）的光强分布为：式中ａ为狭缝宽度，Ｉｐ为...     

用光栅式位移传感器测量衍射光强分布

利用光栅式位移传感器测量了不同缝宽的单缝衍射的相对光强．本文介绍了光栅式位移传感器的测量原理、光栅测量系统、实验装置和调试要求．实验结果表明，利用光栅式测量系统产生的叠栅条纹测量位移的精度较高．     

夫琅禾费衍射的光谱特性

基于MATLAB语言,以夫琅禾费衍射为研究对象,数值模拟了夫琅禾费圆孔衍射和单缝衍射光谱特性,通过改变狭缝宽度和入射波的波长,数值模拟得到夫琅禾费单缝衍射的光强变化图和光谱特性图。结果表明,圆孔衍射的光强比单缝衍射的光强曲线在次级明纹的强度更加低,夫琅禾费衍射的结论与实际理论和试验吻合的较好。研究结果为夫琅禾费衍射的研究提供参考。     

Infrared Quantitative Study of Acetylation of Microspheres of Polystyrene

Abstract

Fourier transform infrared spectroscopy has been used to study quantitatively the acetylation of monodisperse polystyrene microspheres with diameters ranging from 7 to 9μm. The CH₂ stretching infrared vibration mode at 2921 cm^?1 was used as the internal intensity standard. The acetylation extent could be easily measured by comparing the relative intensities of the bands of acetyl group (1678, 1415, 1359 cm^?1) or the bands due to the para-substituted benzene ring to the band at 2921 cm^?1 from the calibration curve.     

BSA-SDS-Ag聚合物纳米微粒的制备及其水凝胶性质的研究（Ⅰ）

报道了BSA－SDS－Ag聚合物纳米微粒的制备及水凝胶的性质,用X射线衍射（XRD）、透射电镜（TEM）、傅里叶变换红外（FT－IR）光谱考察了这种聚合物微粒的结构,微粒粒径32nm左右,用UV／Vis光谱及SEM考察了冰凝胶的性,表明Ag^ 离子先与BSA产生化学键合,再学原了Ag粒,进行聚合成网状结构的聚合物。     

Application of the method of X-ray fluorescence analysis for determination of the degree of chlorination of copper phthalocyanin

To whom correspondence should be addressd.     

混合物物态方程的计算

 在采用体积相加原理计算混合物物态方程的基础上,建立了一种物理模型确定混合物温度。根据混合物中各组分温度和压强平衡条件,采用压强-密度迭代方法计算给出混合物物态方程,编制了两种组分的混合物物态方程计算程序。为检验建立的温度模型的合理性及程序的有效性,分析了不同密度、温度状态的氢（H2）和钨（W）组成的混合物状态参量,计算了以下情形及其组合情形的混合物物态方程：H₂和W以不同质量比混合;质量比固定,单组分状态不同;温度区间和密度区间不同。研究表明:实际应用中在建立的混合物温度模型基础上确定的混合物物态方程是合理的。     

傅里叶望远镜外场实验性能改进和结果分析

为了实现对傅里叶望远镜成像系统更接近实际的仿真,改进了外场实验系统结构。采用反射式目标,利用准直扩束镜替代空间滤波器和准直透镜,使用大靶面电荷耦合器件作为监视器。在无大气和包含200m水平大气两种情况下,分别对2.5mm的4种不同空间频谱分布目标进行实验。实验选用9×9,17×17,33×33和65×65傅里叶分量分别进行重构。最高成像角分辨率为3.5″。结果表明含大气与无大气重构结果的Strehl比值相近,从而证明傅里叶望远镜成像系统能够克服下行链路低阶大气扰动的影响。     

Electron microscopy study of aggregation of microclusters of sulphur

A study of aggregation of sulphur particles in colloidal suspension of sulphur in water-methanol mixture using TEM and electron diffraction is reported. From the micrographs the aggregates formed have been found to be random and tenuous indicating a fractal structure. The electron diffraction patterns of the aggregates are used to study the mechanism of diffusion and reaction limited aggregation.     

Optical investigation of dynamics of phenomena of laser-based lithotripsy

Using time-resolved high-speed shadowgraphy, the dynamics of phenomena due to laser-based lithotripsy is studied. Collapsing mechanism of bubble formed therein is investigated. In order to study the mechanism, the optically implemented mathematical morphology is applied. The study of the shape of the plasma and the collapsing region of the bubble of fluid that we are studying can possibly be used for practical application for laser-based lithotripsy.     

Some peculiarities of deep PT-changes of physical properties of rocks

Abstract

Results of petrophysical PT-experiments are discussed. Used is a method of program modeling of experiments. Thermobaric dependence of elastic properties of acid, intermediate and basic rocks as well as elastic wave velocity anisotropy in amphibolites is studied. Deep PT-regimes effect on electrical resistance of dry and water-saturated rocks has been studied. PT-conditions of full loss of the remanent magnetization of volcanites have been established. A number of regional petrophysical lithosphere models has been constructed.     

分子费米共振拉曼光谱强度分析

测量了CCl₄和CS₂分子的Raman光谱。用Bertran理论和群论等相关理论对其光谱强度进行了分析,获得了发生费米共振分子的拉曼光谱强度的特殊规律： (1)发生费米共振的基频和倍频(和频)间发生能量转移,两光谱强度大小相互接近,当发生费米共振的基频和倍频(和频)间距离很小时,两发生费米共振的光谱强度相等(R=1);(2)能出现倍频光谱强度高于其基频光谱强度;(3)也会观测到费米共振光谱,而观测不到参与费米共振的和频中的基频光谱。此研究对化学、材料科学中的分子结构、材料成分等研究中的谱线认证、归属有很好的参考价值。     

Simulation of the contours of spectral lines of closed-ARC radiation

Simulated contours of self-reversed lines of Tl at 535 nm (7²S_1/2−6²P_3/2) and 378 nm (7²S_1/2-6²P_1/2) in alternating-current closed-arc radiation in mercury vapor with an addition of Tll were compared with experimental contours. It is shown that while a single self-reversed contour has many different sets of model parameters that ensure coincidence of experimental and calculated profiles, in the case of operation with a large data file of contours that correspond to different directions of observation along chords perpendicular to the discharge axis, and with different lines that have a common level, such a set of parameters becomes virtually unique. Instantaneous spatial distributions of Hg and Tl atoms in the ground state and of Tl atoms in the 6²P_3/2 state are determined and the parameters of the van der Waals broadening of the 7²S_1/2 level are found. It is shown that a considerable “red” shift of absorption contours in the outer layers of the discharge is observed. The results obtained contradict the presumed existence of local thermodynamic equilibrium in the given discharge. Reported at the Conference “Plasma Physics and Plasma Technologies,” Minsk, September 15–19, 1997 Petrozavodsk State University, 33, Lenin Ave, Petrozavodsk, 185640, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 761–768, September–October, 1998.