纳米多层膜的电性能及表面形貌

用热蒸发沉积和自然氧化法制备纳米量级的Al／Al2O3及Cr／Cr2O3薄膜和多层膜．本文采用三点法测定了常温、低温下的U—I特性，发现常温、低温下纳米量级的Al／Al2O3及Cr／Cr2O3薄膜具有类似负阻的特性。SEM检测表明，薄膜表面均匀，薄膜的厚度和称重法所得的厚度基本相符．AFM和STM观察表明薄膜表面存在着岛状结构，表面粗糙度在纳米尺度范围内。     

不同底层(Ag, Ti, Cu, Pt)对[Fe/Pt]n多层膜磁性的影响

利用磁控溅射的方法, 在热玻璃基片上制备了[Fe/Pt]n多层膜, 经不同温度真空热处理后, 得到L10有序结构的FePt薄膜(L10-FePt).实验结果表明 [Fe/Pt]n多层膜结构可使FePt薄膜的有序化温度由500 ℃降到350 ℃, 350 ℃退火20 min后其平行膜面矫顽力可达到421.8 kA·m-1.同时以Ag, Ti, Cu和Pt做底层, 利用[Fe/Pt]n多层膜结构制备了FePt薄膜, 磁性和X射线衍射结果表明 与[Fe/Pt]n多层膜相比, 四种底层均没有进一步降低FePt薄膜的有序化温度, 其中Ag做底层对[Fe/Pt]n多层膜退火后的平行膜面矫顽力影响较小, 但能够提高其垂直磁各向异性;其他底层均会降低[Fe/Pt]n多层膜在高温退火时的平行膜面矫顽力, 且对其垂直磁各向异性无改善作用.     

Approximate Feedback Linearisation Using Multilayer Neural Networks

In this paper we introduce the approximate feedback linearisation using multilayer feedforward neural networks. We propose to approximate a basis of the one-dimensional codistribution of an affine nonlinear system with the derivative of a multilayer neural network [6] and form a change of coordinates with n multilayer neural networks [5]. In this paper we will prove that the transformation can define a local diffeomorphism, with which a local stabilising feedback law can be designed for a kind of non-linearisable nonlinear systems.     

Development of a system for measurement of permeability of aroma compounds through multilayer polymer films by coupling dynamic vapour sorption with purge‐and‐trap/fast gas chromatography

A system for measurement of permeability of aroma compounds through laminated polymer films was constructed by combining dynamic vapour sorption (DVS) with purge‐and‐trap/fast gas chromatography (P&T–fGC). Data validation was achieved by measuring the permeability of limonene across an HDPE film (film C) and comparing the permeation data with the literature values. The general applicability of this system, as well as its potential for simultaneous measurement of permeability of multiple aroma compounds, was demonstrated by measuring the permeability of limonene and ethyl butyrate as single permeants or as co‐permeants under different environmental conditions (at 25°C, 30°C or 35°C and 0% or 75% RH) through three different multilayer polymer films (film A, HDPE/EVOH/HDPE/HDPE; film B, HDPE/nylon/HDPE/HDPE; film C, HDPE/HDPE). The results showed that the aroma barrier performance of plastic films was determined by the polymer composition and was affected by various factors, such as temperature and the presence of other co‐permeants. Simplicity, speed and accuracy were some of the attractive features of this system, which indicates its potential as a useful tool that could be applied in the food industry for screening or selection of appropriate packaging materials for specific applications. Copyright © 2004 John Wiley & Sons, Ltd.     

网络控制论的多层多重视点模型体系研究

建模分析是网络控制论中重要的分析方法,传统的模型不能全面地描述并分析网络控制论系统中的复杂问题。首先提出了多层多重视点模型体系;然后从网络控制论系统模型的分类、多层多重视点模型体系和建模的一般步骤3个方面,详细阐述了网络控制论的多层多重视点模型体系;通过实例表明:多层多重视点模型体系具有全局性、清晰性和主动性的特点,是分析网络控制论系统的一种有效方法。     

X射线超反射镜设计

阐述了一种新的X射线超反射镜的设计方法,它是基于经验理论公式的解析设计方法和基于计算机的数值优化设计方法相结合的产物。利用前者提供比较好的初始膜系,再利用后者对该初始膜系进行优化处理,从而获得比较好的设计结果,并大大减少了计算时间。讨论了实际制作出的多层膜存在的表面粗糙度及膜层材料间的相互扩散对多层膜反射性能的影响,并给出了模拟计算的结果。依据上述方法,在比较大的掠入射角情况下,设计出了具有较宽反射带宽的W/CX射线超反射镜。     

基于Web数据库动态访问技术的Java实现

对基于Ｂｒｏｗｓｅｒ／Ｓｅｒｖｅｒ模式下的Ｉｎｔｒａｎｅｔ网的几种Ｗｅｂ动态访问技术进行了分析,讨论了这几种技术的优缺点,详细论述了ＪａｖａＳｅｒｖｌｅｔ、Ｊａｖａ、Ａｐｐｌｅｔ与ＪＤＢＣ相结合的技术,并就这一方案进行了改进,使用了一我层体系工将将其应用实际的Ｉｎｔｒａｎｅｔ的Ｗｅｂ开发实践中去。     

集成学习算法的研究与应用

集成学习算法的思想就是集成多个学习器,并组合它们的预测结果,以形成最终的结论。典型的学习模型组合方法有投票法,专家混合方法,堆叠泛化法与级联法,但这些方法的性能都有待进一步提高。提出了一种新颖的集成学习算法--增强的集成学习算法（ReinforcedEnsemble）。ReinforcedEnsemble集成算法由两大部分组成：ReinforcedEnsemble特征提取算法与ReinforcedEnsemble基分类器。通过实验,将ReinforcedEnsemble算法与其他集成学习算法进行了性能比较。实验结果表明,所提出的算法在多项指标上均达到最优。     

多层陶瓷电容器的技术现状及未来发展趋势

重点介绍了片式多层陶瓷电容器(MLCC)的技术现状,综述了多层陶瓷电容器(MLCC)的小型化、高容量、贱金属化及环保化的发展趋势。     

基于IAPF与多层Morphin搜索树的移动机器人路径规划

针对传统人工势场法(artificial potential field,APF)的易出现振荡、死区、局部极小值等缺陷。提出一种结合机器人位置、速度、加速度及障碍物位置等信息的改进人工势场法(improved artificial potential field,IAPF)。利用Morphin算法计算效率高、易结合全局路径规划算法的优点,提出一种多层Morphin搜索树算法。首先,利用改进人工势场法完成路径的全局规划,在此基础上在障碍物附近用多层Morphin搜索树算法进行路径规划。利用MATLAB仿真测试表明,所提出的改进人工势场法与多层Morphin搜索树的混合算法,在移动机器人自主路径规划中,能有效缩短路径长度,提高到达目标点的效率,高效完成路径规划。