一种新型电子标签天线用导电油墨的配制

基于电子标签天线对导电性要求较高的特性,实验以自制Ag作为导电填料。论文采用液相化学还原法,以次磷酸钠为还原剂,还原硝酸银制备纳米银胶。通过控制反应条件(温度、pH值等)、反应物的量(六偏磷酸钠、PVP),制备出粒径分布均匀、分散稳定性优良的纳米银胶。通过向银胶中添加电解质,析出纳米银粉,加上适量的助剂、溶剂和分散剂,制备了水性丙烯酸树脂和水性聚氨酯基导电油墨。分析了影响油墨导电性能的各影响因素。     

基于3-D打印技术的新型微波/毫米波无源波导器件

综述了近年来基于多种3-D打印工艺的微波直至太赫兹频段无源波导器件的发展研究现状,并介绍了作者所在小组研制的多个基于立体光刻3-D打印工艺的滤波器(包括基于新型高Q值单模和双模球形腔体谐振器的X频段带通滤波器以及基于裂缝波导和紧凑片上结构的W频段带通滤波器).这些滤波器射频性能的测量与仿真结果吻合良好.与相同形状的铜制器件相比,采用非金属材料的3-D打印器件的重量减轻了80%以上,并保持了优良的射频性能.     

基于多次滤波技术的单次曝光三维物体数字全息

为了改善数字全息重构像质量以达到可实际利用的目的,首先采用以马赫-曾德尔干涉仪为基础的三维物体全息实验光路,运用单次曝光的方法,记录了真实三维物体的数字全息图。由于对该全息图直接计算得到的重构像,受零级衍射光斑和散斑噪声的影响较大,使得重构像质量难以令人满意。为此采用了一套独特的多重滤波数字图像处理方法,即综合运用小波分析与收缩加权平均滤波对实验获得的数字全息图及其数字重构像进行滤波处理,成功地消除了数字重构像中的零级衍射光斑、减小了散斑噪声的影响,得到逼真的三维物体重构像。实验结果表明,该方法简便、实用,可显著提高三维物体重构像的质量。由于采用单次曝光,无需记录多幅图像,此方法便于在实时图像分析处理等领域中应用。     

汽车发动机连杆激光3-D打印工艺研究

为了研究汽车发动机连杆激光3-D打印制造工艺,采用理论分析和实验验证的方法,建立了连杆3-D数据模型,进行了分层切片处理,通过S型扫描和轮廓偏移扫描,规划两种连杆加工路径。选用铁基合金粉末以及相应的工艺参量,在激光3-D打印系统中进行连杆打印试验。扫描单层轨迹用时4min30s~4min56s,总用时4h20min。结果表明,连杆成形区底部的金相组织主要是柱状晶和树枝晶,中上部是细小的等轴晶,层间致密搭接,形成良好的冶金结合;成形连杆显微硬度为450HV~490HV,屈服强度为754MPa,抗拉强度为1189MPa,延伸率为9%。连杆激光3-D打印成形制坯性能相比于锻造、粉锻制造工艺,减少了工装成本支出并缩短了生产准备工时,其屈服强度、抗拉强度等力学性能超过钢锻连杆,与国外粉锻连杆相比,差别不大,能满足连杆制坯要求。     

基于数字条纹投影的三维形貌测量技术研究与实现

根据投影机和照相机的光学成像原理,借用双Ig测量系统的标定方法搭建了一套测量精度高、标定过程自动化的基于数字条纹的三维形貌测量系统,并采用最新的相位展开技术用较少的条纹图像完成相位展开,通过对人脸石膏像进行测量实验,验证了系统模型和测量方法的正确性。     

Analysis of 3-D metallization structures by a full-wavespectral-domain technique

A full-wave method for the investigation of microstrip and coplanar structures including 3-D metallization structures is presented. The spectral-domain analysis method is used to calculate the S-parameters of unshielded microwave components containing bond-wires and air-bridges. The general formulation and the implementation procedure of the method are described. The application of the theory is given by a comparison of measured and calculated results for a spiral inductor, including an air-bridge     

Spherical harmonics based intrasubject 3-D kidney modeling/registration technique applied on partial information

This paper presents a three-dimensional (3-D) shape reconstruction/intrapatient rigid registration technique used to establish a Nephron-Sparing Surgery preoperative planning. The usual preoperative imaging system is the Spiral CT Urography, which provides successive 3-D acquisitions of complementary information on kidney anatomy. Because the kidney is difficult to demarcate from the liver or from the spleen only limited information on its volume or surface is available. In this paper, we propose a methodology allowing a global kidney spatial representation on a spherical harmonics basis. The spherical harmonics are exploited to recover the kidney 3-D shape and also to perform intrapatient 3-D rigid registration. An evaluation performed on synthetic data showed that this technique presented lower performance then expected for the 3-D shape recovering but exhibited registration results slightly more accurate as the iterative closest point technique with faster computation time.     

光学层析技术测量三维非对称温度场

采用卷积背投影公式实现了位相物体的三维非对称温度场的重建,为光线偏折型测量三维非对称温度场提供了高精度分析和处理实验数据的方法。     

基于ardunio的3D打印控制系统设计

3D打印技术给社会生产生活带来很多便利,但目前市面上销售的3D打印设备造价昂贵,精度难以控制.基于此,设计开发出一款基于ardunio的3D打印控制系统,并进行硬件电路和软件设计,实现硬件各模块的高耦合性.所设计的3D打印控制系统能够实现精度达标、价格低廉、设备小型,具有很好的应用前景.     

基于傅里叶变换去隔行图像的动态3维面形测量

为了解决动态面形测量中隔行扫描CCD相机记录动态物体表面变形条纹图像存在缺陷的问题,提出了傅里叶变换去隔行算法,即把隔行扫描CCD获取动态物体的错位模糊帧图像分成两个单场图像,分别对每一单场图像进行傅里叶变换去隔行处理,再利用条纹分析法重建对应时刻的3维面形。理论分析得出单场傅里叶变换去隔行图像与对应的准确满帧图像相同的结论。结果表明,该方法可以很好地恢复条纹和重建物体,且简单实用,可用于基于空间相位检测、相位测量轮廓术、傅里叶变换轮廓术等条纹分析方法的动态物体3维测量中。     

A novel dimension-reduction technique for the capacitanceextraction of 3-D VLSI interconnects

In this paper, a new capacitance extraction method called the dimension-reduction technique (DRT) is presented for three-dimensional (3-D) very large-scale integration (VLSI) interconnects. The DRT converts a complex 3-D problem into a series of cascading simple two-dimensional (2-D) problems. Each 2-D problem is solved separately, thus we can choose the most efficient method according to the arrangement of conductors. We have used the DRT to extract the capacitance matrix of multilayered and multiconductor crossovers, bends, vias with signal lines, and open-end. The results are in close agreement with those of Ansoft's SPICELINK and the Massachusetts Institute of Technology's (MIT) FastCap, but the computing time and memory size used by the DRT are several (even ten) times less than those used by SPICELINK and FastCap     

A novel technique for the approximation of 3-D antenna radiation patterns

In this paper, a novel technique for the approximation of three-dimensional (3-D) antenna radiation patterns is presented. The proposed method combines the two principal cuts in order to acquire an adequate estimate of the 3-D antenna radiation solid. The absolute error from the theoretical solution is analyzed along with other statistical measures for various types of antenna structures, namely omni-directional and directive arrays. The performance of the method is compared against other existing extrapolation algorithms. The proposed technique exhibits low approximation errors and is easily integrated into 3-D radio propagation planning tools (such as ray-tracing algorithms).     

基于Split-Field FDTD法的近埋地无限长散射体二维算法

提出了一种基于周期结构split-field FDTD法的近埋地无限长散射体二维算法.该方法根据散射体轴向均匀性将三维split-field FDTD法转化为二维算法,减少了内存和计算量,可分析斜入射脉冲波照射下近地、埋地无限长散射体散射问题.为了进一步减小计算量,连接边界上的入射波(地上为原始入射波和反射波的叠加,地下为透射波)采用一维FDTD法引入.吸收边界采用了UPML匹配层,导出了适用于split-field FDTD算法与有耗介质匹配的UPML方程.通过数值算例,验证了此二维算法应用于近埋地无限长散射体问题的有效性和实用性.     

基于条纹跟踪的动态过程三维轮廓术

针对在快变化动态过程三维轮廓术中,成像设备拍摄频率不满足抽样定理,对物体表面动态条纹时间采样不足以及物体表面发生破裂的动态过程,提出一种采用标记条纹进行跟踪的动态过程三维轮廓术,能有效地解决因成像设备时间采样不足和条纹断裂对三维相位展开所带来的影响问题,获得物体正确的动态面形分布,计算机模拟证实了此种方法的正确性。     

基于彩色编码条纹投影的孤立物体三维测量

针对空间分布呈区域状、不连续的孤立物体采用条纹投影与相位分析方法进行三维面形测量时,很难得到可靠的相位展开这一问题,提出了通过先后投影两幅π相移的彩色编码正弦条纹到孤立物体表面,方便快捷地还原对应区域颜色信息,同时利用截断相位分布的阶跃边界获得更准确的分色结果,用以指导相位展开。实验验证了方法的有效性。     

An algorithm for coding video signal based on 3-D wavelet transformation

This paper presents an algorithm for coding video signal based on 3-D wavelet transformation. When the frame order t of a video signal is replaced by order 2, the video signal can be looked as a block in 3-D space. After splitting the block into smaller sub-blocks, imitate the method of 2-D wavelet transformation for images, we can transform the sub-blocks with 3-D wavelet. Most of video signal energy is in the decomposed low-frequency sub-bands. These sub-bands affect the visual quality of the video signal most. Quantizing different sub-bands with different precision and then entropy encoding each sub-band, we can eliminate inter- and intra-frame redundancy of the video signal and compress data. Our simulation experiments show that this algorithm can achieve very good result.     

Interpolation of 3-D binary images based on morphological skeletonization

In this paper, the morphological skeleton interpolation (MSI) algorithm is presented. It is an efficient, shape-based interpolation method used for interpolating slices in a three-dimensional (3-D) binary object. It is based on morphological skeletonization, which is used for two-dimensional (2-D) slice representation. The proposed morphological skeleton matching process provides translation, rotation, and scaling information at the same time. The interpolated slices preserve the shape of the original object slices, when the slices have similar shapes. It can also modify the shape of an object when the successive slices do not have similar shapes. Applications on artificial and real data are also presented.     

A new approach for creating defined geometries by navigated laser ablation based on volumetric 3-D data

This paper describes a new approach for laser bone treatment according to a preoperative plan. The advantages of using laser systems are the free choice of the cutting geometry and the possibility of bone treatment without any severe thermal damage. On the other hand, the control of bone removal depth is difficult. Due to the lack of haptical feedback, it is only possible to control the bone removal visually. In addition, by selecting wrong laser parameters and incorrect handling,the tissue can sustain thermal damage. To solve this problem, an approach of navigated and model-based calculation of depth ablation has been investigated. The focus of this paper was to verify the feasibility of precise and safe laser bone removal by combining navigation information with mathematical and volumetric modeling. For the mathematical modeling, known approaches are used. On the basis of CT data, cavities in a bovine bone were planned with a navigation system. With an optical measurement system, the position of the laser handpiece was calculated relative to the bone. Using a mathematical model, the theoretical cavity depth was calculated for each laser pulse and displayed on the navigation screen. Thereby, the material removal was determined in a volume model. With this information, five cavities were created by the laser using constant energy settings. A final measurement of the cavitiespsila depths showed an error of less than 1 mm.     

基于图形理解的室内建筑三维重建算法

根据室内建筑行业特有的视图表示规则,提出了一种基于理解的室内建筑物三维重建方法。该方法结合室内建筑制图规则、图形识别理解技术和人工智能知识,通过基于特征抽取的识别算法,完成对室内建筑结构图中墙体中线的提取,进而获得整个建筑物墙体的拓扑结构;然后对室内建筑结构图中2种重要的建筑构件:门和窗户进行辨识;最后实现室内建筑物的三维重建。实验结果表明,在少量人机交互的基础上,该方法对实际的建筑图是十分有效的。