用于低温环境的铂电阻温度微传感器

目前,铂电阻温度传感器主要应用于73 K(-200℃)以上环境的温度检测。设计了可用于10 K(-263℃)～200 K(-73℃)低温区的铂电阻温度微传感器。铂电阻温度微传感器采用对称的折回型结构,这种结构有效地降低了交流感抗的影响。传感器的敏感薄膜是一层采用磁控直流溅射沉积厚度为200 nm的铂薄膜。采用QD PPMS仪器测试传感器的电阻与温度的变化关系,得出传感器的电阻温度系数(TCR):研制的温度传感器的电阻温度系数在温度高于30K(-243℃)时可达到9980×10-6/K,同时在低于30K(-243℃)的深低温区域TCR也可达到3730×10-6/K。     

NiCrAlY薄膜应变计的研制

采用射频磁控溅射法在Ni基高温合金拉伸件上制备NiCrAlY薄膜应变计。研究了热稳定处理对NiCrAlY薄膜结构、表面形貌的影响,并且测试了NiCrAlY薄膜应变计的电学与应变性能。结果表明：热稳定处理后 NiCrAlY 薄膜应变计由于在表面形成了一层 Al2 O3膜,具有抗高温氧化的特性,在室温～800℃范围内,应变计电阻同温度呈线性变化,电阻温度系数（ TCR）约为290×10－6/℃,室温下的应变计系数（ GF）为2.1。     

一代新型温度传感器

本文讨论了铂薄膜温度传感器的设计、制造工艺、膜料与衬底及封装材料的关系。报道了研制成的薄膜铂电阻性能全面符合IEC751标准。     

高Tc 超导薄膜热敏红外探测器 的物理特性和工艺研究

本文对以高T_C超导薄膜为探测元的热敏红外探测器进行了理论分析和模拟设计.对影响器件性能的关键因素——热导G和电阻温度系数α,作了深入的理论分析,得到器件结构参数的最佳设计.在此基础上开展了相关的工艺研究:YSZ缓冲层和YBCO超导薄膜的制备;硅基片的微机械加工技术及YBCO膜的激光刻蚀技术.     

一步法制备的ZnO-硼硅酸铅锌玻璃压敏电阻电性能研究

以四足状纳米ZnO粉末为原料,以制备硼酸铅锌玻璃的氧化物替代硼酸铅锌玻璃直接进行共烧结,制备出了ZnO-硼硅酸铅锌玻璃压敏电阻,并对其电性能进行了研究.研究结果表明:最佳添加量为13.0 wt%～17.4 wt%.当添加量在13.0 wt%～17.4 wt%时,在900～1 170℃温度范围,烧结温度对压敏电阻的漏电流IL和非线性系数α的影响很小.含13.0 wt%添加剂的样品,其最大非线性系数α和最小漏电流IL分别为38.7和1.7 μA.烧结温度的降低主要源自于纳米ZnO粉末和添加了硼酸铅锌玻璃"形成"氧化物.     

薄膜铜电阻温度传感器

<正> 本文研制的薄膜铜电阻温度传感器具有如下性能:测温范围:-50～+150℃,最大非线性度<0.5％,电阻温度系数4150±20ppm℃~(-1),响应时间<0.5s。 制备薄膜铜电阻温度传感器的工艺流程如下:抛光硅片(p型或n型)清洗→热氧化→     

中国微米纳米-微纳结构对电容式柔性压力传感器性能影响的研究

设计制备出三明治结构的电容式柔性压力传感器,并对其性能进行研究.该传感器以银纳米线为电极材料,聚二甲基硅氧烷(PDMS)为柔性衬底,同时采用毛面玻璃和光面玻璃分别作为柔性衬底的制备模板,制备出微纳结构和平面结构的PDMS薄膜.然后采用喷涂法制备AgNWs/PDMS复合电极,以另外一层PDMS为介电层,将两电极面对面封装,得到电容式柔性压力传感器,最后系统研究了传感器的电极微纳结构对器件性能的影响.本文研究表明,具有微纳结构的AgNWs/PDMS复合薄膜传感器的灵敏度为1.0 kPa-1,而平面结构的AgNWs/PDMS复合薄膜传感器的灵敏度为0.6 kPa-1,由此可知具有微纳结构的柔性衬底能够显著提高器件的灵敏度.     

中国微米纳米-PdCr薄膜电阻应变计研制及其高温应变敏感性能研究

在航空航天以及核电领域中,准确测量高温部件的应变、疲劳等结构参数十分重要,对满足高温应用环境的高温应变计需求非常迫切.在镍基合金基底上研制了PdCr薄膜电阻应变计,依次在基片上沉积NiCrAlY作为过渡层来增强附着性,沉积YSZ/Al2O3作为复合绝缘层满足绝缘性需求,溅射PdCr合金作为应变敏感层,并采用金属掩模对PdCr敏感层进行图形化,最后沉积Al2O3薄膜层作为高温保护层,并对PdCr薄膜应变计的应变敏感系数(GF)以及高温环境下的表观应变、漂移应变等性能进行了表征.结果表明,不同温度下PdCr薄膜应变计的电阻值随应变呈良好的线性关系;在常温下,其应变敏感系数为1.40;在800 ℃时,应变计的表观应变系数127 με/℃.应变计的电阻值随时间线性减小,导致的漂移应变约为1 800 με/hr,应变敏感系数为1.41.同时,对制备的PdCr薄膜应变计进行了可靠性评估和寿命评估.结果表明,其重复性测量误差约为5.71%,工作寿命超过10 h.     

MEMS铂薄膜温度传感器的电阻温度系数研究

采用MEMS工艺在硅衬底上制备了铂电阻薄膜温度传感器,在500℃、600℃、700℃和800℃四个温度点下对铂电阻样品进行了热处理,对样品在退火前后的电阻值进行了测试和对比分析,对800℃的退火样品的阻温特性进行了多次测量,其在零摄氏度的电阻温度系数可达3150×10-6/K。另外还对退火后的铂电阻样品阻温特性进行了多次升温降温测试,其升温曲线和降温曲线基本重合,表明退火处理可以明显的改善铂薄膜温度传感器的稳定性和重复性。     

自标定薄膜温度传感器的研制与标定

由于尺寸小,使用常规热电偶静态标定方法标定薄膜热电偶时,在标定过程与使用过程中,传感器和补偿导线上的温度梯度分布不一致,使薄膜热电偶的热电势也不同,影响其测温准确性。为解决这一问题,设计了集薄膜金—铂热电偶和薄膜铂电阻器于一体的自标定薄膜温度传感器及其标定系统,使用电子印刷法制备传感器,采用激光加热技术模拟其使用时的温度分布,通过有限元仿真分析其温度分布规律,基于温度外推实现薄膜热电偶静态特性自标定。结果显示,传感器中的薄膜热电偶在室温到300℃内的塞贝克系数为5. 3～7. 6μV/℃。     

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.