高性能ZnV Sb系压敏电阻陶瓷的制备

在传统工艺基础上,对V2O5/Sb2O3混合粉体先进行热处理,然后以热处理产物为主要掺杂剂,在950℃合成了显微结构均匀、相对密度98%以上、α大于50的ZnVSb系多元压敏电阻陶瓷材料。并研究了V2O5/Sb2O3预合成粉含量对材料显微结构和性能的影响。结果表明:V2O5/Sb2O3预合成粉含量升高,增大了晶界受主态密度,提高了材料的晶界势垒,使材料在压敏电压升高的同时,非线性系数得到改善。     

三角形谱啁啾光纤光栅在光栅传感系统中的应用

利用三角形谱啁啾光纤布拉格光栅（T-CFBG）的反射和时延特性,提出了一种新的基于相位检测的FBG解调方案。该方案由光强来确定传感器光栅反射波长的相位延迟角范围,由相位检测来确定在该范围的相位延迟角大小,两者结合给卅传感光栅的反射波长,因此具有更高精度和更大波长检测范围。实验制作了宽带宽具有三角形反射谱的T-CFBG,并对其用于传感解调予以了模拟分析。     

光学和电子束曝光系统之间的匹配与混合光刻技术

介绍如何实现光学和电子束曝光系统之间的匹配和混合光刻的技术，包括：(1）光学曝光系统与电子束曝光系统的匹配技术；(2）投影光刻和JBX-5000LS混合曝光技术；(3）接触式光刻机和JBX-5000LS混合曝光技术；(4）大小束流混合曝光技术或大小光阑混合曝光技术；(5）电子束与光学曝光系统混合光刻对准标记制作技术. 该技术已成功地应用于纳米器件和集成电路的研制工作，实现了20nm线条曝光，研制成功了27nm CMOS器件；进行了50nm单电子器件的演试；并广泛地用于100nm化合物器件和其他微/纳米结构的制造.     

纳米电子器件及其集成

对基于Top-Down加工技术的纳米电子器件如：单电子器件、共振器件、分子电子器件等的研究现状、面临的主要挑战等进行了讨论. 采用CMOS兼容的工艺成功地研制出单电子器件，观察到明显的库仑阻塞效应；在半绝缘GaAs衬底上制作了AlAs/GaAs/In0.1Ga0.9As/GaAs/AlAs双势垒共振隧穿二极管,采用环型集电极和薄势垒结构研制的共振隧穿器件，在室温下测得其峰谷电流比高达13.98，峰电流密度大于89kA/cm2；概述了交叉阵列的分子存储器的研究进展.     

宽带隙ZnMgO的电学特性及其透明薄膜场效应晶体管

首次提出了用六方相晶体结构的宽带隙ZnMgO作为薄膜场效应晶体管（TFT）的沟道层，用立方相ZnMgO纳米晶体薄膜作为栅绝缘层，在实验中用透明的ITO导电玻璃作为衬底，通过连续沉积六方和立方相结构的纳米ZnMgO晶体薄膜，并通过光刻、电极工艺等，研制了透明的ZnO基TFT, TFT的电流开关比达到1E4，场效应迁移率为0.6cm2/(V·s).在偏压2.5MV/cm下漏电流为1E-8A.     

基于BiCMOS技术的高速数字/模拟转换器

基于BiCMOS技术，进行了高速数字/模拟转换器研究. 以并行输入类型，电流工作模式的16位D/A转换器为载体，进行了电路设计、工艺制作和测试. 在±5.0V工作电压下，测试得到转换速率≥30MSPS，建立时间为50ns，增益误差为±8% FSR，积分非线性误差为1/2 LSB，功耗为500mW.     

A new way for multidimensional medical data management: volume of interest (VOI)-based retrieval of medical images with visual and functional features.

The advances in digital medical imaging and storage in integrated databases are resulting in growing demands for efficient image retrieval and management. Content-based image retrieval (CBIR) refers to the retrieval of images from a database, using the visual features derived from the information in the image, and has become an attractive approach to managing large medical image archives. In conventional CBIR systems for medical images, images are often segmented into regions which are used to derive two-dimensional visual features for region-based queries. Although such approach has the advantage of including only relevant regions in the formulation of a query, medical images that are inherently multidimensional can potentially benefit from the multidimensional feature extraction which could open up new opportunities in visual feature extraction and retrieval. In this study, we present a volume of interest (VOI) based content-based retrieval of four-dimensional (three spatial and one temporal) dynamic PET images. By segmenting the images into VOIs consisting of functionally similar voxels (e.g., a tumor structure), multidimensional visual and functional features were extracted and used as region-based query features. A prototype VOI-based functional image retrieval system (VOI-FIRS) has been designed to demonstrate the proposed multidimensional feature extraction and retrieval. Experimental results show that the proposed system allows for the retrieval of related images that constitute similar visual and functional VOI features, and can find potential applications in medical data management, such as to aid in education, diagnosis, and statistical analysis.     

Automated 2-D cephalometric analysis on X-ray images by a model-based approach

Craniofacial landmark localization and anatomical structure tracing on cephalograms are two important ways to obtain the cephalometric analysis. In order to computerize them in parallel, a model-based approach is proposed to locate 262 craniofacial feature points, including 90 landmarks and 172 auxiliary points. In model training, 12 landmarks are selected as reference points and used to divide every training shape to 10 regions according to the anatomical knowledge; principle components analysis is employed to characterize the region shape variations and the statistical grey profile of every feature point. Locating feature points on an input image is a two-stage procedure. First, we identify the reference landmarks by image processing and pattern matching techniques, so that the shape partition is performed on the input image. Then, for each region, its feature points are located by a modified active shape model. All craniofacial anatomical structures can be traced out by connecting the located points with subdivision curves according to the prior knowledge. Users are permitted to modify the results interactively in many different ways. Experimental results show the advantage and reliability of the proposed method.     

Layered Wyner-Ziv video coding.

Following recent theoretical works on successive Wyner-Ziv coding (WZC), we propose a practical layered Wyner-Ziv video coder using the DCT, nested scalar quantization, and irregular LDPC code based Slepian-Wolf coding (or lossless source coding with side information at the decoder). Our main novelty is to use the base layer of a standard scalable video coder (e.g., MPEG-4/H.26L FGS or H.263+) as the decoder side information and perform layered WZC for quality enhancement. Similar to FGS coding, there is no performance difference between layered and monolithic WZC when the enhancement bitstream is generated in our proposed coder. Using an H.26L coded version as the base layer, experiments indicate that WZC gives slightly worse performance than FGS coding when the channel (for both the base and enhancement layers) is noiseless. However, when the channel is noisy, extensive simulations of video transmission over wireless networks conforming to the CDMA2000 1X standard show that H.26L base layer coding plus Wyner-Ziv enhancement layer coding are more robust against channel errors than H.26L FGS coding. These results demonstrate that layered Wyner-Ziv video coding is a promising new technique for video streaming over wireless networks.     

CMOS有源像素传感器特性分析与优化设计

设计了一个三管有源像素和其用开关电容放大器实现的双采样读出电路.该电路被嵌入一64×64像素阵列CMOS图像传感器,在Chartered公司0.35μm工艺线上成功流片.在8μm×8μm像素尺寸下实现了57%的填充因子.测得可见光响应灵敏度为0.8V/(lux·s),动态范围为50dB.理论分析和实验结果表明随着工艺尺寸缩小,像素尺寸减小会使光响应灵敏度降低.在深亚微米工艺条件下,较深的n阱/p衬底结光电二极管可以提供合理的填充因子和光响应灵敏度.