炭黑/硅橡胶导电复合材料力敏元件温度响应试验研究

利用炭黑/硅橡胶导电复合材料制作了大变形力敏传感元件,对其温度荷载下的电阻响应进行了试验研究,并根据其导电机理对温敏特性进行了深入分析.试验发现制作的大变形力敏传感元件具有正温度系数特性,电阻随温度的升高而增大;温度稳定时,具有电阻弛豫现象.硅橡胶基体随温度变化体积发生变化是造成复合材料温度敏感性的主要原因;同时,温度变化也会影响电子跃迁能力,进而影响到复合材料温度响应.橡胶基体的粘弹性以及试样具有一定厚度的尺寸效应是导致其温度响应滞后性的主要原因.     

大变形力敏传感元件温度响应试验研究

利用炭黑/硅橡胶导电复合材料制作了大变形力敏传感元件,对其温度荷载下的电阻响应进行了试验研究,并根据其导电机理对温敏特性进行了深入分析。试验发现制作的大变形力敏传感元件具有正温度系数特性,电阻随温度的升高而增大;温度稳定时,具有电阻弛豫现象。硅橡胶基体随温度变化体积发生变化是造成复合材料温度敏感性的主要原因;同时,温度变化也会影响电子跃迁能力,进而影响到复合材料温度响应。橡胶基体的粘弹性以及试样具有一定厚度的尺寸效应是导致其温度响应滞后性的主要原因。     

导电橡胶力敏传感器研究进展

介绍了导电橡胶力敏传感器的应用前景,分析了导电橡胶传感器的基本特性。通过对该传感器敏感单元制备过程的研究,指出了影响复合材料导电性能的主要因素包括填料类型、填充量、基体材料性能以及制备工艺等。通过对导电橡胶传感器压阻特性的研究,阐述了导电橡胶复合材料的导电机理。描述了该传感器的结构设计从检测简单的单向压力到检测三维力的发展过程。表述了制约导电橡胶力敏传感器的发展中的主要因素,并对未来研究方向提出了展望。     

炭黑/纳米Al2O3填充柔性压敏导电硅胶体系的研究

基于柔性触觉传感器中用到的压敏导电硅橡胶,研究添加纳米Al2O3对导电硅橡胶电特性的影响.从理论上研究纳米Al2O3改性的微观和宏观机理,并通过实验对添加不同量纳米Al2O3的压敏导电硅橡胶导电性、室温下的导电稳定性、压阻特性进行比较分析.实验结果表明:在炭黑浓度恒定的压敏导电硅橡胶中适量添加纳米Al2O3,可有效提高复合材料的导电性,稳定性,增大复合材料的压力敏感范围.     

用于机器人皮肤的柔性多功能触觉传感器设计与实验

为实现智能机器人皮肤对三维力和温度的检测,设计并制作了一种柔性多功能触觉传感器.基于碳黑-硅橡胶显著的压阻效应设计了四电极对称结构的三维力传感器,基于碳纤维-PDMS(聚二甲硅氧烷)显著的温度敏感效应设计了叉指电极结构的温度传感器,分析了检测三维力和温度的工作原理.针对两种导电复合材料存在的力学/温度敏感特性交叉干扰问...     

罗丹明6G/PMMA复合材料荧光的温度传感特性

罗丹明6G/PMMA(R6G/PMMA)荧光复合材料在室温附近表现出良好的温度传感特性.通过在20℃~60℃温度范围内测试不同配比的R6G/PMMA复合材料的荧光发射光谱,对荧光光强It、谱峰位置λp以及新型荧光特征参数"谱带重心"λB等材料荧光特性的分析表明:①对于不同组分配比的材料,荧光强度均随温度升高而猝灭,光强的温度敏感规律呈线性;②以质量比R6G:PMMA=1:5的复合材料为代表,实验系统作温度传感应用,以谱带重心波长为传感信号的温度传感方程为λB=581.9+0.065T,拟合优度(R2)为0.98,系统的分辨力为1 ℃,以30 ℃测试数据作参考的相对灵敏度为3.3%/℃,精度远远优于谱峰位置作温度传感信号;③荧光复合材料的R6G:PMMA质量比变化基本不影响谱带重心为温度传感信号的灵敏度.本文分析了实验观察到的温敏荧光现象的成因,对基于R6G/PMMA荧光复合材料的新型温度传感器在电磁干扰环境、生物体温监测、大气环境温度监测等方面的应用作出了明确预期.     

新型有机/无机触压传感器材料的制备及性能的研究

以硅橡胶做为基体,通过掺杂导电碳黑和Al2O3纳米粉制成了富有弹性、导电性好、稳定性优良的复合材料,找出了材料导电性突变时碳黑掺杂的体积分数为38%;并对碳黑体积分率不同时的复合材料进行了压阻特性的测量,发现随着材料中碳黑体积分率的增加,材料的弹性变差;进一步利用超声波分散技术将Al2O3纳米粉分散到材料当中,发现纳米粉的加入改善了材料的导电性能和弹性性能.文章最后计算了材料的压阻灵敏度,发现所制备材料的压阻灵敏度可达1.5 Ω/Pa.     

V2O3—PE复合物在140℃空气中氧化对PTC效应的影响

本文研究了氧化对V_2O_3-聚乙烯(PE)复合物PTC材料电性能稳定性的影响,发现由于复合材料中的PE发生氧化反应,会导致PE的体积效应减弱,从而使复合材料的PTC效应随氧化时间的增加而逐渐减弱直至消失.导电粒子V_2O_3的氧化则是导致室温电阻率升高的主要原因.     

用直、交流方法分析高分子电阻型湿敏元件的敏感机理

利用接枝共聚反应合成了具有良好湿敏特性的功能高分子材料,用该材料制作了特性良好的电阻型湿度传感器。利用瞬时直流极性反转法研究了该元件在不同的温度环境中的导电粒子;利用复阻抗分析进一步分析了元件在不同的湿度环境中的导电类型和等效电路。     

碳纳米管/PDMS复合材料柔性阵列压力传感器制备与实验

以碳纳米管（CNTs）作为导电填料,聚二甲基硅氧烷（PDMS）为基体材料,采用溶液法制备出CNTs/PDMS导电复合材料。研究了碳纳米管浓度对复合材料的电学特性和压阻特性的影响规律,得到碳纳米管在PDMS中的渗滤区域。通过复合材料的压力灵敏度优化碳纳米管浓度。以制备的复合材料为敏感材料,FPCB工艺加工的柔性基板为电极,设计制备了一种简单结构和工艺的柔性阵列压力传感器。用零电势法设计了阵列电阻读出电路与LabVIEW实现的上位机配合,实现信号读取和显示。最后通过一个应用实例表明,该柔性阵列压力传感器及信号处理系统可以实现压力分布与大小的实时监测,可为柔性阵列压力传感器设计与制备提供参考。     

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.