基于黑磷烯/氧化石墨烯双介质层的柔性电容式压力传感器

设计并制备了由黑磷烯/氧化石墨烯双层材料为介质层的电容式柔性压力传感器,该传感器结构以ITO为电容上下极板,PET为柔性基底,并对该传感器进行了系统的性能测试与分析。着重研究了该传感器在不同压力量程内的灵敏度,进而分析了其温度漂移特性。测试结果表明,以黑磷烯/氧化石墨烯薄膜为双介质层的电容式柔性压力传感器在0～3.12 kPa压力量程内灵敏度可达到1.60 kPa^-1。同时,对该传感器和以氧化石墨烯薄膜为单介质层的传感器进行了弯曲应变性能的对照实验,可知具有双介质层的传感器结构能够显著提高传感器的输出特性。     

柔性温度压力仿生皮肤的模块化设计与实现

为实现电子仿生皮肤的模块化设计,以石墨烯纳米片制备薄膜温敏传感器,同时,以炭黑/硅橡胶复合材料为弹性电介质、有机硅导电银胶为柔性上极板设计电容式力敏传感器,在此基础上,以聚酰亚胺为柔性基体,提出一种可用作智能机器人仿生皮肤的全柔性温度/压力触觉传感器,并设计成具有可拼接特点的模块化阵列结构.介绍柔性温度/压力触觉传感器的结构设计、检测机理以及信号采集与处理系统.通过温度、压力及温度/压力复合感知实验表明,该柔性温度/压力复合式触觉传感阵列及信号提取系统可实现触觉感知功能,为可穿戴式人工皮肤的研究提供了一种设计方案.     

基于石墨烯压阻效应的宽量程MEMS压力传感器设计

针对传统悬浮式石墨烯压力传感器存在量程小、体积大、非线性度高等问题,设计了一种膜—岛结构的宽量程石墨烯MEMS压力传感器.使用COMSOL有限元仿真软件和噪声分析法对弹性膜片及石墨烯敏感单元尺寸进行优化设计.结果表明:在0～25 MPa范围,传感器最大应变为0.314％,固有频率高达1.3534 MHz;采用TSV垂直...     

柔性膜挤压式压力传感器的研制

本文研制了一种可以测量两平行平面间挤压力的柔性膜式挤压力传感器,总厚度在2.5 mm～4.0 mm的范围.传感器由柔性超弹性材料、硬质材料片及电阻应变片组成.通过在受压膜中局部产生拉应变的方法实现了用电阻应变片测量挤压力的目的.传感器既拥有超弹性材料的柔性特点,同时继承了电阻应变片使用方便,技术成熟稳定、输入输出线性好、零频响以及性能稳定等优点.传感器可在周边约束和周边自由两种方式下工作.通过不同的标定方法,对传感器在周边约束和周边自由两种的性能进行了分析,进而提出了正确使用传感器的方法.该传感器除了挤压力测量外,结构略作改进后可以扩展到其他力学量的测量.以实例的方式给出测量微压力和指尖按压力的两种拓展型传感器的结构,示意性地展示了传感器对于手指接触力以及脉搏跳动的测量.     

基于电容-电阻转换原理的柔性压力传感器

目前,基于碳基纳米材料的柔性压力传感器凭借着其便携性、柔韧性、生物相容性和低成本等特点,在智能医疗、人机交互和智能机器人等领域有着广泛的应用前景,但如何使其在具有较大量程范围的同时保持较高灵敏度,仍是一个严峻的挑战。提出一种基于氧化石墨烯/碳纳米管（Graphene Oxide/Carbon Nanotube, GO/CNT）复合敏感层的柔性压力传感器,同时以热塑性聚氨酯弹性体（Thermoplastic Polyurethanes, TPU）多孔海绵作为传感器骨架。该GO/CNT@TPU柔性压力传感器的量程范围为0～60 kPa,基于电容-电阻转换原理,当受到较小压力（0～5 kPa）时,传感器以电阻感知为主,灵敏度为0.05777 kPa^-1;当受到较大压力（5～60 kPa）时,传感器以电容感知为主,灵敏度为0.33213 kPa^-1。从而有效地实现了传感器的在宽量程内的高灵敏度检测。     

柔性应变织物传感器研究进展

传感器是智能纺织品的重要组成部分.柔性智能传感器具有柔韧性好,可自由弯曲的特性,可使服装在获得智能化的同时保持其原有的舒适性能.以织物为基础的柔性应变传感器能够最大限度地实现与服装的无缝整合,在智能纺织品领域具有很高的应用价值.主要介绍了柔性应变织物传感器的不同制备方法及其应变传感特性.     

Ａｇ ＮＷｓ/ ＭＸｅｎｅ 柔性织物应变传感器的制备及性能研究

柔性应变传感器在柔性可穿戴电子器件中占有重要地位。以氨纶-丙纶弹性织物为柔性基底, 通过浸没涂覆法,以一维银纳米线(Ag NWs)和二维MXene两种导电材料共同作用制备出柔性应变传感器。随后对其进行基本形貌表征、力学性能以及电学性能的分析。结果表明,该应变传感器不仅具有较小的电阻值（~150 Ω/cm）和较高的耐久性（＞500次拉伸循环）,而且通过将该传感器贴合于咽喉部测得的电阻信号显示,该传感器对4个不同单词的发音具有一定的区分度和较好的重复性。因此,表明该应变传感器具有对简单语音进行识别的潜能。     

基于 ＧＮＰｓ/ ＰＤＭＳ 复合薄膜的柔性压阻传感器制备及性能研究

目前柔性压力传感器已被用于众多领域,其中压阻薄膜是柔性压力传感器的核心。本文将石墨烯纳米片（GNPs）与聚二甲基硅氧烷（PDMS）复合,通过倒模的方法制备压阻薄膜,经测试,GNPs浓度为8%时,材料具有较好的性能。以此为基础,制备了压敏结构间距为1.2 mm,直径大小为1.0 mm的GNPs/PDMS基压阻传感器,经测试,所制备的传感器加载响应为340 ms,卸载响应速度为260 ms,并具有较好的稳定性,同时,基于该压阻式柔性压力传感器实现了人体手腕关节处压力信号的测试。     

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.     

柔性压力传感器温度漂移补偿结构设计

温度补偿是对微传感器的性能进行优化与稳定的必要技术方案。提出了一种适用于柔性压力传感器的温度漂移补偿方法及结构,选用高热膨胀系数的聚二甲基硅氧烷(PDMS)与硅橡胶(EcoFlex)作为柔性衬底,结合基底表面微结构设计进行温度补偿。由测试结果分析,未补偿前传感器的TCR系数为-0.57%/K,在EcoFlex、PDMS、表面具有微结构的EcoFlex、以及表面具有微结构的PDMS四种基底上TCR系数分别为-0.42%/K,-0.37%/K,-0.24%/K,-0.22%/K,可知温度漂移得到有效补偿。本研究方法为柔性压阻式传感器的温漂性能优化提供了有益的借鉴作用。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.