浅谈全息图的复制

简要介绍了将原全息图再现和接触复制法两种全息图复制的原理与方法.进一步采用接触复制法的方法,利用激光作为光源进行了全息图的复制实验研究.实验结果表明复制的全息图再现像图像比较清晰,层次分明.     

全息光栅复制技术的研究

介绍全息光栅的复制原理和复制工艺,并运用复制工艺新技术生产全息光栅。与全息照相法相比,具有成本低、合格率高等优点。     

骨胶无底层照相复制镀铬工艺

<正> 照相法制取分划板是利用光化学反应的原理。目前许多厂采用虫胶无底层照相复制镀铬法和聚乙烯醇无底层照相复制镀铬法。这种方法对感光胶的配制要求比较高,而且操作时曝光时间的长短、光线强弱、距离远近对显影都     

PMMA光盘基片光致聚合反应复制法工艺研究

本文通过测量ＰＭＭＡ基片在光致聚合反应法复制过程中的形变和收缩应力，由此对其产生的机理作了一定的理论分析。通过在凝胶化后施加一定的压力能够减小形变和收缩应力。本文不仅描述了采用二阶段加压法工艺复制的ＣＤ唱片，还描述了用ＳＥＭ观察复制信息的微观形貌。     

光学加工方法综述

光学加工方法可以分为两大类:1.常用光学零件传统加工法;2.光学复制方法,即用一个复制模复制出许许多多相同零件的加工方法。本文对这两类加工方法中的各种加工工艺进行了介绍,并论述了这些加工方法中的基本不同点。     

金属铜纳米孔洞阵列膜制备方法研究

以多孔阳极氧化铝膜(anodic aluminum oxide，AAO)为模板，用真空蒸镀法复制了金属铜的纳米孔洞阵列膜，SEM结果表明，制备得到的金属铜纳米孔洞阵列膜形貌与AAO膜一致.此方法简单易行，能大规模生产，为纳米膜的工业化复制提供了一种新的工艺，为纳米线、纳米管等纳米阵列材料的合成与组装提供了有利的条件. 关键词： AAO模板 真空蒸镀 金属铜纳米孔洞阵列膜 纳米复制     

复制法制造光学零件

复制法制造光学零件是美国在复制光栅的基础上于七十年代中期发展起来的新工艺。它不但为非球面和其它特殊形状的光学零件成批生产创造了条件,而且给光学设计带来许多灵活性。这种新工艺首先由美国国防部门应用于军事和空间技术的某些特殊光学零件的制造(例如人造卫星望远镜系统、空中情报收集及照相系统的光学零件),目前已推广到民用市场(例如研究所的某些分析仪器、照相机系统、投影仪系统及信息处理系统中的光学零件)。美国已建立一个专门复制光学零件的公司,并有六个光学公司增设了光学零件的复制车间。图1以非球面反射镜为例说明了光学零件     

对一些特定密着网屏作色调相减处理的方法

本文提出了分析几种特殊的密着网屏网目模式及其所复制的半色调图象的一种基本方法,对于网目呈直线、正方形、圆以及同心圆等形状,并且它们的透过率随空间线性变化的网屏,我们得到了能最逼真地复制图象色调的一组最佳参数。根据这组参数,我们可以设计密着网屏,选择高反差胶片及其曝光和冲洗条件,从而达到最逼真地复制图象之目的。此外,考虑到其它实用因素,我们也将线性网屏与包括正弦形、指数形、对数形等非线性透过率网目的网屏进行了比较。     

TiO2微图纹结构的制作

用软刻蚀技术中具有代表性的方法———微模塑法和转移微模塑法 ,在普通光学玻璃表面成功制备出TiO2 微阵列结构 .首先 ,以钛酸四丁酯为前驱物 ,通过溶胶 凝胶法合成出TiO2 溶胶 ,然后用表面带有微图纹的有机硅橡胶PDMS作为弹性印章分别对所制得的TiO2 溶胶进行微模塑及转移微模塑加工 ,在 70℃下溶胶凝胶 ,进而让凝胶材料在 5 5 0℃下焙烧 2h得到TiO2 微结构 .用光学显微镜对所得到的微结构进行了显微观察 ,显微照片显示 ,微模塑法和转移微模塑法在制备材料微结构方面复制精细度和重复率都比较令人满意 .同时 ,还初步探讨了影响最终图纹复制效果的凝胶温度、外加压力及模板等因素     

利用自相关方法实现光脉冲时间延迟精确测量

为了满足在高精度波分复用/时分复用光采样系统中,采样光脉冲时间抖动低于100 fs的要求,开发了一套基于自相关法测量时间延迟的系统。通过光纤耦合器连接一路参考光路将光脉冲在时域上进行"复制",并使初始光脉冲和"复制"光脉冲相关,得到参考光路和被测光路的精确光程差,进而固定参考光路并接入不同被测光路从而得到多路被测光路之间相对延时。实验结果表明,利用自相关法测量脉冲时间间隔精度优于50 fs,满足波分复用/时分复用光采样系统研究需要。     

三维非结构网格自动生成

采用各向异性平面非结构网格生成技术对曲面的参数平面进行三角剖分,从而得到曲面的非结构网格,作为三维非结构网格的边界网格.应用推进面法生成网格内点,增量法将生成的内点逐点插入现有网格进行网格细化,得到三维计算域的Delaunay非结构网格.讨论了非结构网格质量优化方法.给出几个算例说明方法的应用.     

溃坝流的光滑粒子法模拟

用光滑粒子法模拟几种情况的溃坝流动,对坝外无水和有水的情况进行二维模拟,对坝外有立柱的情况进行三维模拟.流动控制方程采用雷诺平均方程模拟溃坝流动的湍流效应,采用混合长度形式的涡粘模式对控制方程进行封闭,推导其相应的光滑粒子形式的方程.模拟结果表明,数值模拟的流动特征与实验结果符合得非常好,说明发展的光滑粒子法有效.     

Scaled DFT Force Constants and Vibrational Spectrum of Cyclopropylamine

Abstract

The molecular structure and harmonic vibrational frequencies of cyclopropylamine have been calculated using the B3LYP density functional method with the 6‐31G(2d,2p) basis set. The scaled DFT force field gives very good reproduction of the experimental vibrational frequencies. Several of the vibrational fundamental modes assigned previously are reassigned on the basis of the B3LYP/6‐31G(2d,2p) method and the scaled force field calculations. The optimized scaling factors were used to scale the B3LYP/6‐31G(2d,2p) force field of cyclopropane and cyclopropylamine (–ND₂) molecules.     

Evolutionary dynamics of imatinib-treated leukemic cells by stochastic approach

The evolutionary dynamics of a system of cancerous cells in a model of chronic myeloid leukemia (CML) is investigated by a statistical approach. Cancer progression is explored by applying a Monte Carlo method to simulate the stochastic behavior of cell reproduction and death in a population of blood cells which can experience genetic mutations. In CML front line therapy is represented by the tyrosine kinase inhibitor imatinib which strongly affects the reproduction of leukemic cells only. In this work, we analyze the effects of a targeted therapy on the evolutionary dynamics of normal, first-mutant and cancerous cell populations. Several scenarios of the evolutionary dynamics of imatinib-treated leukemic cells are described as a consequence of the efficacy of the different modelled therapies. We show how the patient response to the therapy changes when a high value of the mutation rate from healthy to cancerous cells is present. Our results are in agreement with clinical observations. Unfortunately, development of resistance to imatinib is observed in a fraction of patients, whose blood cells are characterized by an increasing number of genetic alterations. We find that the occurrence of resistance to the therapy can be related to a progressive increase of deleterious mutations.      

多点择优推进阵面法生成曲面三角形网格

在现有曲面非结构网格生成法的基础上,提出了一种新的曲面网格生成法——多点择优推进阵面法.它可在曲面上直接进行三角形网格划分,克服了映射法的网格变形问题,并且可以在网格生成结束后,对曲面网格直接进行Laplace格点松弛光顺.该方法使用简单,不受曲面块类型的限制,且网格质量高,可以为三维非结构网格生成提供高质量的初始阵面,并给出了若干个算例.     

Color reproduction from desktop display to projector based on visual matching

We present a novel method of color reproduction from desktop displays to projectors via visual assessment. The model is based on visual matching nine color patches between a display and a projector. The effects of the method to improve color reproduction are tested for 30 samples by visual and color difference evaluations. The expeirmental results of visual evaluation show that the color reproduction is improved by 87.5%. The maximum, minimum, and average color differences between the displayed colors and the projected ones before and after correction are 28.94, 4.35, 16.78, 16.51, 0.64, and 3.51 △Eab^＊ units respectively, which are consistent with the results of visual evaluation.     

Anomalous biennial oscillations in a Fisher equation with a discretized verhulst term

The dynamics of a biological population governed by a modified Fisher equation is studied by means of Monte Carlo simulations. Reproduction of the population occurs at discrete times, while transport caused by diffusion and conduction takes place on shorter time scales. The discrete reproduction, modeled with a set of coupled logistic maps, exhibits phenomena which are not evident in the usual continuum version of the Fisher equation. Several mechanisms for biennial oscillations of the total population are investigated. One of these shows an ordered coupling between random diffusive motion and the chaotic attractor of the logistic map.     

Spectral Based Color Correction Technique Compatible with Standard RGB System

A spectral turn method is presented as a spectral based color correction method compatible with the standard RGB system by applying the idea of a multi-spectral method. The multi-spectral based color reproduction technique has been proposed for providing independent color of device and viewing conditions. However, it is difficult to replace the RGB devices with high cost multi-spectral devices since the latter have advanced only to the laboratory level. In the proposed method, the standard RGB values are converted into spectral information, then returned to RGB values for different viewing conditions. This process provides more accurate reproduction than the conventional forward process of the color reproduction. An experiment of psychophysical color matching was performed to evaluate the technique. The mixed chromatic adaptation model was applied to the method in the experiment, and the results showed the effectiveness of the proposed method.     

混响环境下目标声场稀疏分解多域声场重放方法

对于封闭空间内的声场重放,传统的多点声压匹配方法 (Cov-PM)依据在目标声场测得的声压直接使用最小二乘来计算扬声器权重。然而这种方法要求较多的目标声场采样点以实现足够的精度。对于一类特殊的声场景,也就是目标声场是由少量声源辐射产生时,提出一种对目标声场稀疏分解的方法来进行混响环境下多域声场重放以降低对目标声场采样数量的要求。该文给出基于目标声场等效源稀疏分解多域重放方法(Sparse-ESM)理论推导,通过数值计算以及实验测试两种方式对比所提方法与最小二乘等效源分解方法以及Cov-PM的声场重放性能。数值结果表明,在600 Hz以上的频段,Sparse-ESM方法的重放误差性能提升明显。实验结果也得出了与数值计算相同的结论。同时,还通过数值计算和实验测试两种方法证明了当目标声场声源方向波动时,Sparse-ESM仍然可以保持与其余两类方法相近的声对比度,并且实现较高的亮区重放精度。     

计算机控制光学表面成形法初值的确定

介绍了计算机控制光学表面成形法的原理,分析了几种非球面度的测量方法,研究了非球面度的不同计算方法对采用计算机控制光学表面成形法加工非球面的影响。从光学零件加工的角度对计算机控制光学表面成形法初值的确定进行了探讨。