太赫兹超表面计算全息

全息术是一种三维成像技术,它已经被应用于多种实际场景。随着计算机科学与技术的迅猛发展,计算全息由于其方便和灵活的特性,已经成为一种广泛应用的全息成像方法。本文回顾了我们近期基于超表面的太赫兹计算全息研究进展。其中,作为全息板的超表面展示出了超越传统光学器件的独特性能。首先,利用超表面实现了对于全息板每个像素的相位振幅同时且独立的调控,进而实现了高质量全息成像。这种新的电磁波操控能力也带来了新的全息成像效果,如利用介质超表面实现了全息像沿传播方向上的连续变化。其次,对超表面在不同偏振态下的响应进行设计,分别实现了线偏振态与频率复用、圆偏振态复用、以及基于表面波的偏振复用超表面全息术。此外,本文提出了依赖于温度变化而主动可控的超表面全息术,为今后计算全息术的设计与实现提供了新的方案,也推动了超表面在实际应用方面的发展。     

ASSM-Ⅱ型声学悬浮泥沙观测系统

本文介绍了一种新型的水文观测设备－“ＡＳＳＭ－Ⅱ型声学悬浮泥沙观测系统”，它可认自动，连续和长时间地实时观测水中悬浮泥沙深度分布和动态变化过程，文中介绍了工作原理框图，技术参数，性能特点及海上现场观测结果。     

基于体全息技术的WDM器件

利用体全息技术制作波分复用器件是一种新方法。本文介绍了此种方法的基本原理和器件的基本性能，并报道了国外对该项技术的研究进展。     

平面近场测试系统在天线测试和诊断中的应用

介绍了天线近场测量的基本原理和HD-1型平面近场测试系统,并对近场测量在实际天线测试中的应用情况、发展方向和应用前景等作了简单的描述。     

复杂目标近场电磁散射的可视化计算方法

首次介绍了复杂目标近场散射计算的可视化方法。采用非均匀有理Ｂ样条曲面（ＮＵＲＢＳ）精确构造任意形状散射体，结合几何体近场透视变换和Ｚ－Ｂｕｆｆｅｒ技术实现了基于Ｗｉｎｄｏｗｓ平台的近场散射计算。提出广义雷达散射截面的概念并给出的若干算例。该方法充分利用了计算机３Ｄ图形设备的几何运算能力，运算速度快，严谨高，可扩展性好。     

三维漫射体真彩色合成似狭缝彩虹全息术

采用合成似狭缝彩虹全息术记录三维漫射体真彩色彩虹全息图，用单波长激光逆光路再现。在记录过程中，不同波长的参考光具有不同的入射角，从而使透镜孔径的有效利用率达到最高，并给出了理论分析和实验结果．     

离轴数字全息记录条件的研究

用振幅全息和菲涅耳衍射理论,分析离轴数字全息记录系统结构参数对数字全息再现的影响,并进行相应的实验验证。理论分析和实验研究结果都表明,如果记录物体和CCD的尺寸固定,记录物体和CCD之间的记录距离将直接影响数字全息再现像的分离状况和系统的分辨率,在保证再现像分离的前提下,缩短物体和CCD之间的距离将有利于数字全息再现像分辨率的提高。     

Design and application of functional absorbers

This paper gives an overview of the research at Institute of Acoustics, Tongji University, on functional absorbers and experience acquired in practical applications over the past three decades. Experiments and analysis of the absorption characteristics of three different geometrical forms of functional absorbers, i.e., panels, cubes and tubes, were conducted with different arrangements. The resulting esthetical effects are illustrated with pictures. Several non-fiber materials are used to compose functional absorbers with advantages both in acoustic properties and in architectural features. Cost effectiveness analysis is also given in order to provide design guidelines.     

Acoustic study of nano-crystal embedded PbO-P2O5 glass

Nano-crystal embedded PbO-P₂O₅ glass has been prepared and characterized by XRD and TEM measurements. The ultrasonic velocity and attenuation measured within the temperature range 80–300 K show significant structure and interesting feature with the presence of nano-crystalline region. The glass samples were prepared by melt-quench method and nano-crystals of different sizes were produced by heat treatment of the glasses for different durations of heating. All the processes were carried out at or above glass transition temperature. A theoretical model that takes account of the effects of thermally activated relaxation, anharmonicity as well as microscopic elastic inhomogeneities arising out of fluctuations has been successfully applied to interpret the variation of ultrasonic velocity and attenuation data. An interesting outcome of this application has been to propose a method for the determination of the size of nano-crystals from the ultrasonic attenuation data.     

像全息的水下应用

基于开发海洋事业的需要，对如何拍摄好水中物体的全息图进行了详细的理论分析，并利用像全息的方法成功拍摄到了一系列富有工艺美感的水下物体的全息图。针对拍摄的全息图进行了细致的定性、定量分析，最后对仪器开发和应用前景作了初步的探讨。