Preparation and characterization of sputtered Cu films containing insoluble Nb

Copper films containing various amounts of insoluble Nb (up to 24.7 at.%) were prepared by r.f. magnetron sputtering. The crystallography and microstructure of the films were investigated for as-deposited and annealed Cu(Nb) thin films. Cu(Nb) thin films are found to consist of non-equilibrium supersaturated solid solution of Nb in Cu with a nanocrystalline microstructure. X-ray diffraction and scanning electron microscope analyses revealed a reduction in the grain sizes of the films with increasing Nb content in the films leading to a grain refinement. The electrical resistivity of as-deposited and annealed Cu(Nb) thin films is found to be low for an Nb content 2.7 at.%. Significant drops in the resistivity were observed for the high Nb contents after annealing at 530 °C which may be due to grain growth and formation of Nb-bearing phase in the film. Microhardness of the films was found to increase with the Nb concentration due to the combined effects of grain refinement and the solute strengthening of Nb.     

Hemocompatibility of lanthanum oxide films fabricated by dual plasma deposition

Lanthanum oxide films were fabricated using dual plasma deposition. X-ray photoelectron spectroscopy (XPS) showed that La existed in the + 3 oxidation state. X-ray diffraction (XRD) revealed a (101) oriented hexagonal structure. Blood platelet adhesion tests and endothelial cell cultures were used to evaluate the hemocompatibility of the as-deposited films. Scanning electron microscopy (SEM) and optical microscopy were employed to evaluate the surface morphology of the blood platelets and endothelial cells on the films. The results showed that the number of adhered, aggregated and morphologically changed platelets was reduced compared to that observed on low-temperature isotropic carbon (LTIC). Endothelial cells culture tests indicated good adhesion and proliferation of human umbilical vein endothelial (HUVE) cells in vitro. Our study suggests that lanthanum oxide films are potential blood-contacting biomedical materials.     

Optoelectronic and microwave transmission characteristics of indium solder bumps for low-temperature flip-chip applications

This paper describes low-temperature flip-chip bonding for both optical interconnect and microwave applications. Vertical-cavity surface-emitting laser (VCSEL) arrays were flip-chip bonded onto a fused silica substrate to investigate the optoelectronic characteristics. To achieve low-temperature flip-chip bonding, indium solder bumps were used, which had a low melting temperature of 156.7/spl deg/C. The current-voltage (I-V) and light-current (L-I) characteristics of the flip-chip bonded VCSEL arrays were improved by Ag coating on the indium bump. The I-V and L-I curves indicate that optical and electrical performances of Ag-coated indium bumps are superior to those of uncoated indium solder bumps. The microwave characteristics of the solder bumps were investigated by using a flip-chip-bonded coplanar waveguide (CPW) structure and by measuring the scattering parameter with an on-wafer probe station for the frequency range up to 40 GHz. The indium solder bumps, either with or without the Ag coating, provided good microwave characteristics and retained the original characteristic of the CPW signal lines without degradation of the insertion and return losses by the solder bumps.     

Tunable Optical Notch Filter Realized by Shifting the Photonic Bandgap in a Silicon Photonic Crystal Line-Defect Waveguide

A tunable optical notch filter was realized by thermally shifting the TM-like (the light's electric field perpendicular to the substrate) bandgap of a silicon photonic crystal slab W1 line-defect waveguide with silica cladding. This device is compact-its footprint is 340times16 mum², excluding the electrode pads. The 3-dB bandwidth of the device was about 5 nm, and the extinction ratio at the center wavelength was as high as 40 dB. A maximum center wavelength shift of 17.9 nm was attained at a heating power of 0.7W, with a tuning efficiency of 25.5 nm/W. The tuning response time was less than 100 mus     

基于图像核心库的SAR图像处理平台的开发模式

设计了一个基于二维矩阵类的图像核心库，巧妙地将图像处理的各个流程进行了封装，实现界面与图像核心过程分离的面向对象的开发模式，然后在算法模式设计上引入动态插件式DLL的技术，通过设计统一形式的DLL算法模块和算法接口，借助独特的文本解析机制使得仅仅更新一个hii文本文件就可以动态地将算法加入平台，实现预期算法与平台分离的目标。     

序言

众所周知，于2000年初发布的IEC61158现场总线国际标准，由于包含了八种类型的总线技术，而宣告多种并存的局面已经形成。这对于各现场总线组织来说，无疑是一个皆大欢喜的结果。然而，对于广大的中国仪器仪表制造企业、用户而言，却意味着将面临新一轮的挑战：中国的现场总线技术和产业该如何发展？记得2000年初，科技部高新司的一位领导曾向我提出：能否用以太网来做现场总线？     

基金会现场总线功能块实例化的原理和实现

基金会现场总线FF是一种专为工业控制应用设计，并得到国际主要自动设备供应商支持的现场总线技术。功能块是FF最具有特色的技术之一，在FF智能仪表等设备的开发及应用中占有非常重要的地位。功能块的实例化是指用户通过组态软件使设备的硬件资源得到充分合理的利用，它是通过现场总线报文规范FMS的Write服务，对功能块应用进程的动作对象写入参数来实现的。功能块的实例化操作已成功得到应用。     

人工自然环境故障-安全控制系统研究

人工自然环境通过调节温度、湿度、光照度等参数,模拟各种自然环境。为提高产品的安全等级,本文提出了一种新的设计方案,在采用分级控制及硬件冗余结构的基础上,对关键电路采取了故障-安全保障措施,提高了系统安全性;针对温湿度之间存在较强耦合,控制精度难于提高的问题,提出了一种新的控制算法,即采用模糊自整定PID算法实现温度控制,采用模糊前馈-PID反馈复合算法实现湿度控制。结果表明,本文提出的控制算法有效地改善了系统控制品质。     

基于Nios的DDS高精度信号源实现

直接数字频率合成器DDS具有极高的分辨率、频率转换速度快、相位噪声低等优点。以ALTERA公司的CPU软核Nios为基础,利用QuartusⅡ软件和SopcBuilder,采用两级DDS和动态分频法,提高了信号源的精度。采用双口ROM可以很方便的同时输出两路具有一定相位差的信号,而且频率幅度可调。另外着重介绍了怎样用Matlab产生波形幅度数据以及最后的仿真验证。