基于QCM的湿度传感器等效电路模型研究

基于石英晶体微天平(QCM)的湿度传感器是一种以石英晶体为核心元件的新型高灵敏度传感器.根据气相中晶体振荡电路的起振和稳定条件,对晶体表面敏感薄膜吸附水分时等效电路参数的变化进行建模,得到了一种新型的基于QCM的湿度传感器等效电路模型.通过电路仿真软件PSPICE对模型进行仿真,并搭建QCM湿度传感器实验测量平台,结果验证了基于QCM的湿度传感器等效电路模型的有效性和正确性,对QCM湿度传感器的振荡电路的进一步设计和优化具有指导意义.     

基于蛋白质修饰的纳米金探针的石英晶体微天平分析

用蛋白质修饰的金纳米颗粒作为探针,采用树枝状放大途径,结合石英晶体微天平(QCM)技术对人免疫球蛋白G(IgG)进行检测.通过在QCM的金电极表面组装一层蛋白A将羊抗人IgG抗体固定于传感界面用以捕获分析物IgG.利用纳米金标记的抗体和由金标抗体及金标蛋白A构成的免疫复合物分别作为一级放大标记物和二级放大标记物,可以显著放大抗原-抗体的识别信号.用QCM对金标抗体和胶体金免疫复合物的放大过程进行了连续监测.对金标抗体的稀释倍数和复合物的组成进行了优化.一级放大和二级放大的频率信号与人IgG浓度在10.9μg/L～10.9 mg/L范围内呈良好的线性关系,经过二级放大后,用QCM可检测低至3.5 μg/L的IgG.     

基于Silicate-1型分子筛修饰的QCM类神经毒气传感器

主要研究Silicate-1型纳米分子筛对类神经毒气有机气体甲基磷酸二甲酯(DMMP)的敏感特性,并结合高灵敏度的石英谐振天平(QCM)研制了DMMP气体传感器.采用Silicate-1型纳米分子筛作为敏感膜材料分别对不同浓度的DMMP气体进行检测.QCM传感器随着气体浓度的增加,响应时间增加,气体吸附量增加;当DMM...     

QCM 气体传感器的优化设计及应用研究

本文主要介绍了一种新型的石英谐振气体传感器 QCM(Quartz Crystal Microbalance) .它具有灵敏度高、稳定性好、抗干扰能力强等特点 ,可用于多种领域 ,本文主要根据计算化学方法 ,研究其对呼吸气体的响应特性 .此外 ,采用电化学方法制备传感器敏感膜 ,设计了相应的测量系统 .从实验结果可看出这一传感器对呼吸气体的响应结果是令人满意的 ,具有实际应用前景     

基于分子筛薄膜探测神经类毒气的传感器研究

采用ZSM-5分子筛材料对神经类毒剂沙林的相似物甲基磷酸二甲脂(DMMP)气体进行了测试。分子筛材料因为具有选择性吸附分子的能力常被用来作为气体敏感材料,但因为其神经类气体极性较强,被吸附后难于解吸附,因此,分子筛材料很少用于检测神经类气体。利用合成的ZSM-5纳米分子筛作为吸附神经类气体DMMP的敏感材料,将其涂布在2个石英晶体微天平(QCM)上进行差频测试,以减小外界的干扰,并提出了用交变电场进行极性分子解吸附的新方法。DMMP气体的探测最小体积分数达到1×10-6,响应时间和解吸附时间分别小于20 s和90 s。     

声纹识别技术及其应用前景分析

声纹识别,是生物识别技术的一种,也称为说话人识别,包括说话人辨认和说话人确认两类,可以广泛应用于国家安全、刑侦、电话银行、智能门禁及娱乐增值等领域.本文在调研国内外研究现状基础上,对其技术发展和应用前景进行了展望.     

基于PVDF膜的QCM对DMMP的气敏特性研究

神经性毒剂是化学战剂的重要分支.为了检测神经性毒剂模拟剂甲基膦酸二甲酯(DMMP),使用毛细管在压电石英晶体(QCM)的电极上滴涂上不同质量的聚偏氟乙烯(PVDF)溶液,干燥后作为敏感膜.室温下测试QCM对不同浓度的DMMP的响应情况,发现QCM的频率变化与气体浓度有着良好的线性关系.该实验结果表明,PVDF可以作为检测DMMP的很好的敏感材料.     

一种QCM信号在线采集系统的实现

石英晶体微天平(QCM)信号采集系统的设计质量是影响其测量精度的重要因素。提出了一种QCM信号在线采集系统的实现方案,给出了系统的结构框图,并对系统电路进行了详细的分析。     

基于有限元分析QCM电极尺寸的优化设计

提出了一种优化石英晶体微天平(Quartz Crystal Microbalance,简称QCM)结构、抑制寄生振动模的设计方法.用Ansys9.0有限元软件直接对QCM进行三维有限元分析,从而避免了一般解析和半解析中对控制方程的简化.首先通过对QCM谐振频率收敛性的分析,验证了有限元计算的正确性;然后分析了不同电极尺寸对QCM振动及能陷情况的影响,并找到了较佳的电极尺寸;最后针对不同电极尺寸的QCM进行了液体测量实验,实验结果验证了基于有限元分析QCM电极尺寸设计方法的有效性.     

氯气传感器的研究

环境中痕量氯气可以对人们造成很大伤害,用化学传感器对其进行实时原位监测十分必要.用于检测氯气的传感器有固体电解质、半导体和光纤等类型,该文就其近年来的研究现状做一综述.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.