Beating of the oscillations in the magnetocapacitance of a MODFET with Rasba spin–orbit interaction

The effect of Rasba spin–orbit interaction (SOI) on the magnetocapacitance of the 2DEG in a MODFET is investigated. We present calculations on the density of states (DOS) of the 2DEG in a MODFET under the influence of both Rasba SOI and weak two-dimensional periodic modulation. Adopting a Gaussian broadening of magnetic-field-dependent width, we present a simple expression for the DOS, valid for the relevant weak magnetic fields and modulation strengths. In the presence of Rasba SOI and for weak potential modulation strengths, a typical beating pattern of the magnetocapacitance oscillations is observed in the low magnetic filed range. A simple relation that predicts the positions of nodes in the beating patterns is obtained. The interplay between the SOI and the periodic potential modulation is discussed.     

基于蒙特卡罗模拟的光纤浊度传感器

在后向散射式浊度测量方法的基础上,采用光纤传感技术,设计了一种Y形光纤束探头结构的浊度传感器,并在光纤束探头前端配置平面镜作为光反射配合目标。根据朗伯比尔定律通过实验研究了消光系数与浊度的线性关系,基于蒙特卡罗法建立了待测液中的光子散射模型,模拟不同检测情形下的传感器接收光强,优化得到光纤束到平面镜的最佳距离。标定接收光强与消光系数的关系曲线用于测量。此法简单高效,能检测消光系数低至0.059cm-1的水质,平面镜的有效使用将传感器灵敏度提高10倍以上。此传感器可用于便携式检测,结合空分和时分复用技术可实现在线监测。     

新型大功率毫米波螺旋线行波管高频系统研究

该文探讨了CVD金刚石材料在宽带毫米波螺旋线行波管中的应用,研究了两类非杆状新型CVD金刚石夹持的螺旋线高频结构,利用MAFIA分析了它们的色散特性、耦合阻抗和衰减常数,与传统的矩形BeO夹持杆和矩形CVD夹持杆高频结构进行了对比,最后将这两类新型高频结构替代国内某毫米波行波管(26-40GHz)中的矩形BeO夹持杆螺旋线高频结构,利用宽带大功率行波管CAD集成环境中的注波互作用模块分析了其大信号工作特性。结果表明,分立CVD金刚石夹持高频系统兼顾了超宽带和大功率,同时由于金刚石直接和螺旋线及金属翼片大面积接触,该结构还具有极好的散热能力,是一种有重要应用前景的高频结构。     

分布式文件交互系统节点身份认证方案

基于分布式云存储系统利用椭圆曲线和散列函数等内容,提出了一种云环境下的双向身份认证方案,实现双向认证过程。新方案的优点在于产生对通信双方公正的会话密钥,同时设计了2种不同类型的认证: 本地网内认证和跨网络认证。最后对该方案进行了安全性和性能分析,证明了本方案具有很强的安全性,能够保护用户的隐私性和抗抵赖性,且具有较低的计算量。该方案满足云存储在通信环境中的需求。     

Human–robot interaction based on gesture and movement recognition

Human–robot interaction (HRI) has become a research hotspot in computer vision and robotics due to its wide application in human–computer interaction (HCI) domain. Based on the explored algorithms of gesture recognition and limb movement recognition in somatosensory interaction, an HRI model of a robotic arm is proposed for robot arm manipulation. More specifically, 3D SSD architecture is used for the location and identification of gesture and arm movement. Then, DTW template matching algorithm is adopted to trace the dynamic gestures. The interactive scenarios and interactive modes are designed for experiment and implementation. Virtual interactive experimental results have demonstrated the usefulness of our method.     

面向残障人士的基于眼动交互的绘画系统

本文建立了一个面向严重肢体残障人士的眼动交互绘画系统.为此,首先给出了眼动数据的预处理与分析方法;为减弱米达斯(Midas)接触问题对眼动行为判别的影响,提出了基于时域约束的注视点聚类算法,可提取出注视点判断用户当前的视点中心,并据此进一步判断用户眼睛行为;针对眼动原始数据中的噪声影响,设计了窗口长度自适应的视点信号平滑处理方法,可减弱视点抖动产生的噪声,实现自由绘画较为平稳的绘画轨迹.在此基础上,设计并实现了基于ASL眼动仪的眼动交互式绘画系统.     

基于B/S模式的高校学生互动信息平台

主要介绍了一个基于ASP.NET开发B/S模式的高校学生互动信息平台的设计与实现过程,包括系统需求分析和系统的功能设计、数据库设计以及主要ASP.NET页面的设计,重点阐述了用户登录模块及用户信息管理模块的实现。     

Chemisorption sensing and analysis using silicon cantilever sensor based on n-type metal-oxide-semiconductor transistor

This paper presents a silicon cantilever sensor based on n-type metal-oxide-semiconductor transistor for chemical sensing and analysis using the chemisorption-induced surface stress sensing principle. The cantilever is along the 〈1 0 0〉 crystal orientation of the (1 0 0) silicon, and the transistor channel is parallel to as well as located at the rear part of the cantilever to obtain high stress sensitivity. The gold film deposited on the bottom surfaces of cantilevers is chemically functionalized with a self-assembled monolayer of 4-mercaptobenzoic acid via the Au-SH covalent bonding. The vapor phase chemical sensing experiments with acetone, ethanol, nitroethane and water vapor as targets are performed. The observed response differentiation implies that the molecular interaction mechanisms between different chemical molecules are different.     

Recent fluid–structure interaction modeling challenges in IC encapsulation – A review

The rapid development of computing software has facilitated multifarious research in integrated circuit (IC) packaging. Complicated and complex processes can be visualized via simulation modeling with this software. The applications of aided software enhance the fundamental physicochemical understanding and visualization of the IC encapsulation process. In this article, fluid–structure interaction (FSI) during IC encapsulation through computer-aided simulation is reviewed based on the amount of substantial work conducted from the past decades to the present. FSI phenomena in various IC encapsulations, such as wire sweep, paddle shift, lead frame deformation, IC chip, and through-silicon via (TSV) deformation, is considered in the review. The significance and challenges of FSI analysis are also highlighted in this article.     

Influence of some factors on the aerodynamic behavior of long-span suspension bridges

As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed (including the vertical and horizontal variations) all increase consequently, which may have unnegligible influence on the aerostatic and aerodynamic behavior of long-span suspension bridges. In this paper, the models of aerostatic and aerodynamic forces are established, in which the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed are both considered. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic and aerodynamic behavior of the bridge are investigated analytically. The results show that the aerostatic behavior is significantly influenced by these factors, but for the aerodynamic stability, it is greatly influenced by the nonlinear wind-structure interaction and the horizontal variation of wind speed, and the other factors have no influence on it.