镍铬薄膜电阻的制备热处理分析

在采用磁控溅射方法制作用于集成电路的镍铬薄膜电阻过程中,发现在对薄膜热处理日寸薄膜的电阻特性发生了有规律的变化,这种变化不是单纯的线形增大或减小.针对这种现象,我们经过分析认为,由于金属薄膜的电阻率不同于块金属的电阻率,已不是定值,它与金属膜厚有着一定的关系,而热处理所产生的凝聚效应、氧化效应和稳态效应对不同厚度的薄膜电阻率的影响程度是不一样的,因此电阻经处理后的变化值最终表现出不同的变化趋势.这一现象的发现对我们今后在集成电路镍铬合金薄膜电阻的设计优化方面具有较高的参考意义.     

NiCr薄膜微加热器在低温环境下的电学特性研究

设计了一种适用于深低温环境的微型加热器。使用AC磁控溅射技术将NiCr(80/20 at.%)合金沉积到SiO2/Si基底上,并采用微加工工艺实现薄膜图形化,作为加热器的加热元件。研究了NiCr薄膜的电学性能和晶体结构与退火条件之间的关系。实验表明:在450℃氮气环境下退火30min,可以获得深低温性能优良的NiCr加热器。该加热器在20K时的电阻温度系数(TCR)为80.80×10-6/K。X射线衍射(XRD)分析显示NiCr薄膜在450℃氮气环境下退火后,薄膜的结晶度增大,因此,退火条件对薄膜的电阻率和电阻温度系数有较大的影响。     

离子束溅射薄膜压力传感器的力学特性

用数学建模的方法将相同结构参数的离子束溅射薄膜压力传感器和粘贴式应变计压力传感器动态特性做比较,二者在瞬态特性上基本相同。但在宽脉冲方波气压激励下,所用溅射薄膜压力传感器出现响应失真现象。对问题的产生原因和机理进行分析,认为问题的产生原因可能在于方波压力上升沿导致的被测气体温度变化。     

非晶态薄膜压力传感器的研究

本文介绍的是文献[1]的第二轮研制工作,包括:①用射频溅射非晶态NiSiB薄膜应变片的制备新工艺;②敏感弹性元件的设计;③薄膜压力传感器的构造与性能。 虽然,NiCrMe合金、Ta_2N合金等性能较好且已有应用,但是,我们仍采用非晶态的NiSiB的合金。原因在:它的电阻变值与所受应变值间线性关系范围宽,最大静态应变可达10~(-2);应变灵敏系数为2～3;电阻温度系数在210℃以下仅(0～6)×10~(-6)K~(-1);电阻率达153μΩ·cm;耐腐蚀、顺磁性,所以它是一种较为理想的薄膜应变片材料。     

离子束溅射薄膜压力传感器的动态特性

用数学建模的方法将相同结构参数的离子束溅射薄膜压力传感器和粘贴式应变计压力传感器动态特性做比较 ,二者在瞬态特性上基本相同。但在宽脉冲方波气压激励下 ,所用溅射薄膜压力传感器出现响应失真现象。对问题的产生原因和机理进行分析 ,认为问题的产生原因可能在于方波压力上升沿导致的被测气体温度变化。     

基于SOI的硅微谐振式压力传感器芯片制作

采用SOI硅片,基于MEMS技术,设计并加工了一种新型三明治结构的硅微谐振式压力传感器,根据传感器敏感单元的结构设计,制定了相应的制备工艺步骤,并且针对湿法深刻蚀过程中谐振子的刻蚀保护等问题,提出了一种基于氮化硅、氧化硅和氮化硅三层薄膜的保护工艺,实验表明,在采用三层薄膜保护工艺下进行湿法刻蚀10 h后,谐振子被完全释放,三层薄膜保护工艺对要求采用湿法刻蚀镂空释放可动结构具有较高的实用价值。最后对加工完成的谐振式压力传感器进行了初步的性能测试,结果表明,在标准大气压力下谐振子的固有频率为9.932 kHz,品质因数为34。     

二氧化锡薄膜气敏传感器对常见室内污染气体的 电阻2温度特性及机理分析

采用无机试剂(SnCl2·2H2O)为原料,用溶胶-凝胶提拉法制备了二氧化锡薄膜及相应的气敏传感器,并研究了二氧化锡薄膜气敏传感器在常见室内污染气体气氛中的电阻-温度变化关系.结果发现不同气氛下电阻-温度特性各不相同,由此可以获得被测气体的相关信息.本文还用分子轨道计算软件对四种室内污染气体的分子轨道进行了计算,并根据分子轨道能级的相对位置定性解释了二氧化锡薄膜气敏传感器在不同气氛中的电阻-温度曲线.通过对甲醛、苯、甲苯、二甲苯四种气体电阻-温度曲线的测试可以确定被测气体的种类.     

基于弹性膜片的薄膜溅射式拉力传感器研究

介绍了一种基于弹性膜片结构的拉力传感器,敏感元件薄膜电阻应变栅采用离子束溅射、光刻技术与弹性体结合成一体。文中给出了传感器的基本结构及零点补偿和信号转接电路,介绍了薄膜电桥的制备过程,并对弹性体进行了仿真与分析。实验结果显示,该传感器在满量程范围内能满足设计要求,其额定载荷为850 N,灵敏度优于0.01377 mV/N。且其安全过载系数约为6.62,为同类拉力传感器的2~3倍。对传感器的标定表明,该传感器的综合误差不大于额定输出的0.013%。     

康铜薄膜电阻应变传感器的制作

在应变元件与应变膜之间允许直接形成一体的场合下,把应变电阻元件沉积在接受应变的弹性元件上,将使应变传递性能大大改善,这是不言而喻的.但需解决应变电阻膜与接受应变的金属弹性片间的绝缘层问题.本文介绍作者研制的康铜薄膜电阻应变传感器的制造工艺和测试结果,证实了采用双层介质膜是解决绝缘隔离这一技术难点的良好途径.     

200MHz高传输效率薄膜变压器的设计与制备

实现了一种新型的基于硅IC工艺的微波铁氧体集成薄膜变压器.铁氧体薄膜采用射频磁控溅射法制备,SEM观察了SiO2层上铁氧体膜的表面形貌,表明薄膜容易开裂;能谱仪对薄膜成分的分析表明铁氧体薄膜与SiO2层和Al膜附着性差.通过溅射工艺参数及增加热处理等工艺初步解决了以上存在的薄膜制备工艺与IC工艺之间的兼容性问题.采用标准硅基IC工艺设计和制备了这种新型结构的薄膜变压器,对一组薄膜变压器样品的实验参数在20～210 MHz的频率范围内作了测试.测试结果表明:对于设计的匝数比为1的薄膜变压器,在90～210 MHz的频率范围内能获得最高为79%的变压比和良好的波形传输能力.     

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.     

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.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate