三层硅加速度敏感芯片BCB键合工艺研究

采用非光敏苯并环丁烯(BCB)进行MEMS压阻式加速度敏感芯片三层结构制作.BCB键合具有工艺温度低、键合表面要求低等特点,适用于芯片的圆片级封装.但是固化过程中BCB粘度随温度升高而下降,流动性变大,在毛细作用的影响下沿着微小间隙流淌,导致可动部件粘连,器件失效.通过控制BCB厚度、增加BCB阻挡槽解决了可动部件粘连问题,制作了三层硅结构的加速度敏感芯片.样品漏率小于1.0×10-10pa.m3/s,键合剪切强度大于20 MPa,能够满足航天、工业、消费电子等各领域的应用需求.     

间接电位法测定铝

用氟离子选择电极作指示电极,间接测定铝的研究已有报道。本文在对铜离子选择电极间接测定铝的一系列条件试验,探索的基础上,建立了适用于铝合金及水样中的高、中、微量铝的测定方法,通过实际样品分析获得满意的结果。方法简便、快速、准确,宜于推广应用。用铜离子选择电极作指示电极,电位滴定,间接测定铝。方法是在室温和严格的 pH条件下,于体系中加入(定量)过量的 EDTA 将铝全部络合,反应如下:(?)(过)EDTA+Al3~+(?)EDTA—Al(|||)然后用标准的铜溶液除去未与铝络合剩余的 EDTA,其反应:     

三层硅加速度敏感芯片BCB键合工艺研究

采用非光敏苯并环丁烯﹙BCB﹚进行MEMS压阻式加速度敏感芯片三层结构制作。BCB键合具有工艺温度低、键合表面要求低等特点,适用于芯片的圆片级封装。但是固化过程中BCB粘度随温度升高而下降,流动性变大,在毛细作用的影响下沿着微小间隙流淌,导致可动部件粘连,器件失效。通过控制BCB厚度、增加BCB阻挡槽解决了可动部件粘连问题,制作了三层硅结构的加速度敏感芯片。样品漏率小于1.0×10 10Pa.m3/s,键合剪切强度大于20 MPa,能够满足航天、工业、消费电子等各领域的应用需求。     

YSZ表面粗糙度对氧传感器性能的影响

借助表面粗糙度测试技术和循环伏安方法,研究了用Pt浆法制备Pt/YSZ电极过程中,YSZ表面粗糙度对其性能的影响。研究表明:Pt/YSZ电极制作时,所用金刚石磨片粒径大小对YSZ表面粗糙度间距参数无明显影响,但YSZ表面粗糙度高度参数则随着金刚石磨片粒径的增大而增大;当所用金刚石磨片粒径为44μm时,电极阴极活性(电位为-0.4 V时)最低,10μm时最高,约为44μm所制电极的2倍,其他电极则介于两者之间。     

接触角滞后对变截面微通道内水银液滴流动特性影响的数值仿真研究

微通道中气-液两相流的流动特性复杂,影响因素众多,表面效应成为了微流体流动的主要影响因素。在表面张力作用下,静态接触角由固相和液相物性决定,而动态接触角和接触角滞后则受表面粗糙度、表面不均匀性、表面污染等很多因素的影响。本文利用FLUENT中的VOF-CSF模型研究了惯性微流体开关中水银微液滴在变截面微通道内两相流的流动特性。通过动态和静态接触角滞后的UDF函数对变截面微通道中内流动特性的影响进行了数值仿真分析。结果表明,接触角滞后对水银微液滴的流动特性有重要影响,接触角滞后性越大,水银液滴越难通过微阀而进入储液槽闭合信号电极。由于水银液滴在加速度作用下接触线运动速度较低,动态接触角对流动特性的影响可以忽略,动态接触角可由静态接触角代替。     

氟离子选择电极固定电位法测定铝的研究

铝与氟生成多级络合物,其平均配位效为(?)=(C_F~-—[F~-])/C_(Al),在一定实验条件下,当[F~-]一定时,(?)为一常数,因而 C_(Al)与 C_F~-呈线性关系。本文用氟离子选择电极作指示电极,在pH=3.8、I=0.5的溶液中,用固定电位标准曲线法实现铝的测定.     

条纹沟槽表面润湿性的试验研究

通过对铝基板及不锈钢基板上条纹沟槽表面接触角的测试,研究了条纹沟槽对材料表面润湿性的影响.试验用条纹沟槽表面采用准LIGA技术制备.该技术以波长为300～400 μm紫外光作为曝光光源,包括显影、表面活化、微电铸和去胶等工艺.接触角的测试采用DSA100接触角测试仪,选用液滴体积为5 μL.试验结果表明,条纹沟槽的存在...     

H2O和O2在Al(111)表面吸附的密度泛函理论研究

采用第一原理密度泛函理论中的广义梯度近似计算方法对H2O和O2分子在Al(111)表面的吸附性质进行了结构、能量和电子分析,系统研究了这2种气体分子在Al(111)表面的吸附行为及其与Al(111)表面的相互作用机理。计算结果表明：H2O分子易在Al(111)表面的top位吸附且构型倾斜时最稳定,整个吸附过程为弱的化学吸附;吸附过程中表面铝原子的电子向H2O分子发生转移,H2O分子自身的构型仅受微扰作用。O2分子在Al(111)表面的吸附倾向于以分子键平行于表面,表面铝原子向O2分子的电荷转移是O2分子解离的驱动力,吸附过程中O2分子易发生解离,解离后的氧原子稳定吸附于fcc位,其次为hcp位,整个吸附过程为强的化学吸附。     

粗糙表面的可控润湿性研究*

本文利用微机械加工技术,通过改变材料表面微观几何结构,研究材料表面微结构对于表观润湿性的影响规律.我们在以前工作的基础上,分别研究了不同设计尺寸的表面微柱阵列结构的亲水表面的表观接触角的变化,研究结果表明,通过改变材料表面的微结构,在亲水的本征表面上,粗糙表面的表观接触角更加符合Wenzel的理论预测.文章也通过在微柱表面利用化学腐蚀方法制作多孔硅结构的方法,形成了具有阶层结构的粗糙表面.具有多孔硅结构和微柱阵列的疏水表面(OTS)上,测得最大接触角是157.18°.     

疏水表面冷凝的可控毛细力微对象操作方法与实验

提出一种疏水表面冷凝的可控毛细力微操作方法,所研制的液滴操作手可实现操作液滴的动态控制,相应地调控液桥毛细力.建立疏水表面冷凝的单液滴生长模型,分析最小液滴半径、过冷度、饱和温度等参数的影响;通过拾取和释放理论模型,讨论微对象的拾取和释放进程;搭建微操作实验系统,实验分析疏水探针端面液滴冷凝及影响毛细力变化的因素.1 mm×1 mm×0.52 mm微型硅片(重力12.1μN)和直径200μm、壁厚4μm薄壁微球(重力5.069 n N)的操作实验验证了该方法的有效性.     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。