Exponentially weighted moving average-based procedure with adaptive thresholding for monitoring nonlinear profiles: Monitoring of plasma etch process in semiconductor manufacturing

Recently, there are many situations where the quality of a process is characterized by a relationship of functional data (or profiles) such as time series and image data. Such data have been used for detecting out-of-process and quality improvement in many engineering applications such as semiconductor manufacturing, automobile manufacturing, and nano-machining systems. The functional data contain high dimensionality, high feature correlation, non-stationality, and large amount of noise. Due to such characteristics, most classic statistical process control (SPC) may not perform on-line monitoring satisfactorily on functional data. In addition, local shift monitoring with functional data is more significant than the detection of global shifting patterns. In this paper, wavelet-based exponentially weighted moving average (EWMA) test statistic with adaptive thresholding method, which extracts several significant coefficients from original functional data in the wavelet domain and monitors out-of-control events, is proposed. Instead of monitoring global shifting, the local shifting in functional data is of major significance in our study. Throughout this study, we use a spectroscopy in monitoring of plasma etching process from semiconductor manufacturing to illustrate the implementation of the proposed approach. Experiment studies show that the proposed approach quickly detects smaller local shifts compared with the well-known methods.     

深圳市液化天然气与混合动力巴士排放试验研究

利用高精度的移动排放测试仪,对液化天然气巴士和混合动力巴士进行城市典型道路工况下的排放测试,对比分析车辆的排放特征。试验结果表明:液化天然气车较之混合动力车的一氧化碳排放有较大下降,氧化氮排放较为接近,而碳氢化合物排放远高于混合动力巴士;总体而言,LNG车三种污染排放因子随着车速的增加而不断减少,但三种污染物排放速率却随着车速和加速度的变化增减不一;混合动力车因其纯电动起步模式和加速时采用电机辅助驱动,使得其三种污染物在15~20 km/h排放达到最佳,在加速度为0时一氧化碳和碳氢化合物排放达到最大值,而氧化氮在加速度0.5 m/s2附近达到最大。     

混凝土试件的声发射特性试验研究

声发射技术是近年发展起来的一种动态无损检测方法,可用于材料性能评价和结构损伤检测。通过研究混凝土芯样试件在不同压力条件下产生的声发射计数和声信号强度,以及重复荷载作用下的凯塞效应,可以了解混凝土材料的声发射特性,为研究混凝土材料的损伤规律、断裂机理提供基础资料,并为利用声发射技术动态监测大坝混凝土裂缝的形成和扩展的可行性提供佐证。     

An integrated new product development framework – an application on green and low-carbon products

Companies need to be innovative to survive in today's competitive market; thus, new product development (NPD) has become very important. This research constructs an integrated NPD framework for developing new products. In stage one, customer attributes (CAs) and engineering characteristics (ECs) for developing products are collected, and fuzzy interpretive structural modelling (FISM) is applied to understand the relationships among these critical factors. Based on quality function deployment (QFD), a house of quality is then built, and fuzzy analytic network process (FANP) is adopted to calculate the relative importance of ECs. In stage two, fuzzy failure mode and effects analysis (FFMEA) is applied to understand the potential failures of the ECs and to determine the importance of ECs with respect to risk control. In stage three, a goal programming (GP) model is constructed to consider the outcome from the FANP-QFD, FFMEA and other objectives, in order to select the most important ECs. Due to pollution and global warming, environmental protection has become an important topic. With both governments and consumers developing environmental consciousness, successful green and low-carbon NPD provides an important competitive advantage, enabling the survival or renewal of firms. The proposed framework is implemented in a panel manufacturing firm for designing a green and low-carbon product.     

基于TC1766的混合动力汽车整车控制器的开发

开发了一种并联式混合动力汽车的整车控制器,以英飞凌32位单片机TC1766为微控制器,阐述了各个功能模块的硬件实现以及系统电磁兼容设计,在排放实验室进行了车载整车功能和性能试验.试验表明开发的整车控制器具备良好的控制品质,可满足混合动力汽车的动力、经济和环保要求.     

基于西门子S7-300的锅炉厂自动化改造

新世纪国家对于锅炉厂的节能减排工程大力扶持.本文针对某烟厂的锅炉厂房整体改造,在不影响生产的前提下完成整体锅炉及自动化的改造.并通过改造前后具体设备的使用性能等,完成对于节能减排的目标.     

NiO电极中YSZ添加量对NOx传感器气敏性能的影响

以钇稳氧化锆(简称YSZ,Yttria-Stabilized Zirco nia)为固体电解质,添加不同摩尔比例YSZ的NiO+YSZ混合体为敏感电极材料,通过丝网印刷技术制备了相应的混合电势型NOx传感器.采用XRD和SEM手段对NiO混合物进行了物理性能分析,利用电势和阻抗测量设备对传感器样品的输出电势(EMF)和交流阻抗等电学参数随NO浓度的变化进行了研究.结果显示:NiO+YSZ的混合体中,物相独立,没有新相产生;在相同NO检测环境下,敏感电极中YSZ所占摩尔比例为20mol%时传感器的响应电势最大且在0.O1 Hz～100 kHz范围内的阻抗谱最小,SEM也显示此时具有很好的TPB.     

Harnstoffhydrolyse für die selektive katalytische Reduktion von NOx: Vergleich der Flüssig‐ und Gasphasenzersetzung

In order to reduce the NO_x concentration in car exhausts usually the selective catalytic reduction with ammonia is used. However, to avoid the transport of ammonia in vehicles urea is applied as NH₃ precursor. Controlled urea decomposition before the injection into the exhaust gas system itself may be accomplished by the use of a separate reactor. Urea decomposition to ammonia in the liquid phase under pressure in a heated reactor was compared to its decomposition in the gas phase. In the liquid phase, higher conversion rates relative to the reactor volume were realized than in the gas phase. Catalysts which showed high activity in the gas phase influenced the decomposition in the liquid phase only slightly.     

A comparative numerical study of hybrid-stabilized argon–water electric arc

The paper presents numerical simulations of the discharge and the near-outlet regions of the hybrid-stabilized argon–water electric arc. Two different numerical methods for solving the set of conservative equations for the continuity, momentum and energy have been applied. The major difference between the results using the two methods occurs in the temperature distribution in arc fringes within the discharge chamber. This fact influences the potential drop, overpressure, reabsorption of radiation and arc efficiency. It is shown that the radial profiles of temperature at the exit nozzle are less influenced by different temperature distribution within the discharge chamber. Comparison with chosen experimental temperature profiles shows very good agreement.     

Zwitterionic diaminodicyanoquinodimethanes with enhanced blue-green emission in the solid state

Diaminodicyanoquinodimethane molecules which show strong solid state emission in the blue-green region are developed. The new materials are structurally characterized; extended supramolecular assemblies mediated by H-bond interactions are observed in the crystal lattice. Spectroscopic studies including life-time and fluorescence quantum yield measurements in the solution and solid states are carried out. Emission in the solid state is ∼400 times stronger than that in solution; this can be attributed to the inhibition of the excited state geometry relaxation to a non-radiative state, in the solid. Impact of the molecular structure in the crystals on the solid state light emission is discussed. Semiempirical computational studies provide useful insight into the various structural and spectroscopic features of the new materials. The present observations serve as a pointer to further design strategies for realizing novel blue photoluminescent molecular materials based on the diaminodicyanoquinodimethane framework.