一种基于新型数据预测方法的MICA仿真研究

在多元统计过程监控中,为解决因未知过程数据统计分布而产生误报漏报的现象,提出一种结合多向独立元分析法(MICA)和广义相关系数(GCC)数据预测的综合方法,进行在线监控过程的仿真。MICA分析方法能有效分解各变量的关联关系,且不需考虑建模数据是否符合正态分布,用此方法计算的独立元变量能更好地描述过程的变化规律。为提高预报未来过程故障的能力,提出用广义相关系数法进行数据预测:确定与运行轨迹相似的监控模型库中的轨迹,并使其相应部分承接于运行轨迹之后。现场采集聚氯乙烯聚合过程的数据进行仿真,仿真结果显示:对于在线监控和在线故障诊断方面,这种新型预测方法优于其它传统处理预测问题的方法。

用于工业过程监测的无线传感器网络路由协议研究

微电子、无线通信、自动控制和人工智能等领域的技术进步，推动了无线传感器网络的发展。无线传感器网络改变了人与自然的交互方式，是二十一世纪最具影响的IT技术之一，在军事、环境、医疗、家庭、工业和其它领域有广阔的应用前景。 路由协议是目前传感器网络研究的重要内容，协议设计与网络应用密切相关。在工业无线监测应用中，路由协议设计的主要目标是提高可靠性和降低节点能耗；而传统网络路由协议设计的首要任务是提供高质量的数据服务。这些不同导致传统网络的路由协议不能直接应用于工业过程监测网络。论文针对工业无线监测应用的需求和特点展开研究工作，主要包括以下几方面内容。 论述了工业无线传感器网络路由协议设计所面临的挑战性问题，系统地总结了已有研究成果与不足，具体分析了在工业过程监测环境下无线传感器网络的特点和路由需要重点解决的问题。 分析了工业过程监测应用对传感器网络的路由需求，并实地测试了工厂车间环境下的信道质量。 针对这些工业应用的实际需求，提出了在减少协议开销、降低协议能耗的同时提高数据传输可靠性的路由机制，以满足不同现场设备对数据路由的需求。 针对工业过程监测网络中的上行数据量大且具有周期性的特点，提出了一种基于链路质量估计的逐跳多径路由协议。该协议使数据在每一跳的转发过程中都有多条路径可以使用，在提高转发成功率的同时避免了端到端多路径机制带来的大量开销。 针对工业过程监测应用中下行数据量少且具有非周期性的特点，提出了基于分布式编址算法的主动路由协议。该协议中，传感器节点分配到下行地址之后就可以计算出下一跳转发地址，从而避免了采用基于广播转发的方式，大大减少了路由开销。同时，单播转发的下行数据不会引发“广播风暴”，减轻了对网络中周期性上行数据转发的影响。 针对手持设备所具有的移动性、数据量少和通信不频繁的特点，设计了面向移动设备的低开销按需路由协议。该协议只在手持设备有远程连接需求的时候才建立主路由，然后按需延长，避免手持设备每移动一次就要重新进行路由发现。此外，在路由发现环节利用了已经建立好的主动路由，通过单播方式转发路由发现报文，不但大幅减少了协议开销，同时也保证了所选路由的高质量。 为了测试本文提供的路由协议在工厂车间内的实际效果，构建了一个工作在2.4GHz上的验证系统。该验证系统以网络层的可靠性机制为基础，通过在链路层采用TDMA机制、FDMA机制和在传输层重传等机制的配合，达到了较高的报文传输可靠性，证明本文提出的路由协议能够满足工业过程监测应用的需要。

Monitoring A Micromechanical Process In Macroscale Carbon Nanotube Films And Fibers

The evaluation of mechanical properties of carbon nanotube (CNT) fibers is inherently difficult. Here, Raman scattering-a generic methodology independent of mechanical measurements-is used to determine the interbundle strength and microscopic failure process for various CNT macroarchitectures. Raman data are used to predict the moduli of CNT films and fibers, and to illustrate the influences of the twisting geometries on the fibers' mechanical performances.

Rapid automated in-situ monitoring of total dissolved iron and total dissolved manganese in underground water by reverse-flow injection with chemiluminescence detection during the process of water treatment

Measurement of iron and manganese is very important in evaluating the quality of natural waters. We have constructed an automated Fe(II), total dissolved iron(TDI), Mn(II), and total dissolved manganese(TDM) analysis system for the quality control of underground drinking water by reverse flow injection analysis and chemiluminescence detection(rFIA-CL), The method is based on the measurement of the metal-catalyzed light emission from luminol oxidation by potassium periodate. The typical signal is a narrow peak, in which the height is proportional to light emitted and hence to the concentration of metal ions. The detection limits were 3 x 10(-6) mu g ml(-1) for Fe(II) and the linear range extents up to 1.0 x 10(-4) and 5 x 10(-6) mu g ml(-1) for Mn(II) cover a linear range to 1.0 x 10(-4) mu g ml(-1). This method was used for automated in-situ monitoring of total dissolved iron and total dissolved in underground water during water treatment. (C) 1997 Elsevier Science B.V.

Biosensors for fermentation process control

Two biosensors for fermentation process control have been introduced, which were developed in our lab recently. One is an enzyme electrode-based on-line monitoring system for glutamate fermentation process control and the other is an H+-ISFET-based ENFET for penicillin G fermentation process control.

Biosensors for fermentation process control

Two biosensors for fermentation process control have been introduced, which were developed in our lab recently. One is an enzyme electrode-based on-line monitoring system for glutamate fermentation process control and the other is an H+-ISFET-based ENFET for penicillin G fermentation process control.

Monitoring catalytic degradation of dye molecules on silver-coated ZnO nanowire arrays by surface-enhanced Raman spectroscopy

Catalytic degradation of organic dye molecules has attracted extensive attention due to their high toxicity to water resources. In this paper, we propose a novel method for the fabrication of uniform silver-coated ZnO nanowire arrays. The degradation of typical dye molecule rhodamine 6G (R6G), as an example, is investigated in the presence of the as-prepared silver-coated ZnO nanowire arrays. The experimental results show that such composite nanostructures exhibit high catalytic activity, and the reaction follows pseudo-first-order kinetics. Furthermore, these nanowire arrays are desirable SERS substrates for monitoring the catalytic degradation of dye molecules. Compared with traditional UV-visible spectroscopy, SERS technology can reflect more truly the catalytic degradation process occurring on the surface of the catalysts.

Rapid optimization of process conditions for cultivation of transgenic Laminaria japonica gametophyte cells in a stirred-tank bioreactor

Batch cultivation for transgenic kelp gametophyte cells was investigated in an online controlled 5 L stirred-tank photo-bioreactor to rapidly optimize the process conditions by monitoring the rate of increase of pH. The transgenic kelp gametophytes with heterologous gene encoding hepatitis B surface antigen (HBsAg) could rapidly grow in the bioreactor. Optimal temperature and agitation rate for bioreactor cultivation of gametophytes were 15 degrees C and 200 rpm. Optimal incident light intensities depended on the initial cell densities. (c) 2006 Elsevier B.V. All fights reserved.

Monitoring microbial populations of sulfate-reducing bacteria using an impedimetric immunosensor based on agglutination assay

An impedimetric immunosensor was fabricated for rapid and non-labeled detection of sulfate-reducing bacteria, Desulforibrio caledoiensis (SRB) by immobilizing lectin-Concanavalin A using an agglutination assay. The immobilization of lectin was conducted using amine coupling on the surface of a gold (Au) electrode assembled with 11-Mercaptounclecanoic acid. Electrochemical impedance spectroscopy (EIS) was used to verify the stepwise assembly of the sensor system. The work conditions of the impedimetric immunosensor, such as pH of the buffer solutions and the incubation time of lectin, were optimized. Faradic impedance spectra for charge transfer for the redox probe Fe(CN)(6)(3-/4-) were measured to determine SRB concentrations. The diameter of the Nyquist diagram that is equal to the charge-transfer resistance (RI) increased with increasing SRB concentration. A linear relationship between R-ct and SRB concentration was obtained in SRB concentration range of 1.8 to 1.8 x 10(7) cfu/ml. The variation of the SRB population during the growth process was also monitored using the impedimetric immunosensor. This approach has great potential for simple, low-cost. and time-saving monitoring of microbial populations. (C) 2009 Elsevier B.V. All rights reserved.

Monitoring and simulation of water, heat,and CO2 fluxes in terrestrial ecosystems based on the APEIS-FLUX system

The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, monitor, and assess environmental disasters, degradation, and their impacts in the Asia-Pacific region. The system primarily employs data from the moderate resolution imaging spectrometer (MODIS) sensor on the Earth Observation System- (EOS-) Terra/Aqua satellite,as well as those from ground observations at five sites in different ecological systems in China. From the preliminary data analysis on both annual and daily variations of water, heat and CO2 fluxes, we can confirm that this system basically has been working well. The results show that both latent flux and CO2 flux are much greater in the crop field than those in the grassland and the saline desert, whereas the sensible heat flux shows the opposite trend. Different data products from MODIS have very different correspondence, e.g. MODIS-derived land surface temperature has a close correlation with measured ones, but LAI and NPP are quite different from ground measurements, which suggests that the algorithms used to process MODIS data need to be revised by using the local dataset. We are now using the APEIS-FLUX data to develop an integrated model, which can simulate the regional water,heat, and carbon fluxes. Finally, we are expected to use this model to develop more precise high-order MODIS products in Asia-Pacific region.