声表面波气体传感器化学敏感膜研究进展

化学吸附敏感膜是声表面波(SAW)气体传感器的关键组成部分.本文介绍膜材料对化学蒸气的吸附原理及SAW传感器响应的理论计算方法;对敏感膜材料的研究现状作了综述,包括有机聚合物、超分子化合物、无机物膜材料、分子液晶以及生物分子;展望了膜材料的发展前景.     

FTIR光谱法在气态环境污染事故应急监测中的应用

介绍了傅立叶变换红外光谱点式和开放光程式两种监测方法在气态环境污染事故应急监测中的应用，对两种方法的应用效果作了比较。     

便携式色谱质谱联用仪在水质应急监测中的运用

本文建立便携式色质联用仪快速测定水中挥发性有机物的方法,该方法适用于突发性环境污染事故中水质挥发性有机污染物的应急监测。     

生物传感器在环境监测和发酵工业中的应用

生物传感器技术是一项迅猛发展的高新技术，近年来已成为科学界的研究热点之一。本文简述了生物传感器的工作原理、分类，回顾了其在环境监测和发酵工业中的应用，并对其发展前景作了预测及展望。     

GasID的基本原理及其在环境应急监测中的应用

介绍了GasID便携式气体分析仪工作的基本原理-傅立叶红外技术以及在环境应急监测中应用的特点,并与其他应急监测仪器进行性能比较分析.     

Neural,fuzzy and neuro-fuzzy approach for concentration estimation of volatile organic compounds by surface acoustic wave sensor array

Present study evaluates application of adaptive neuro-fuzzy inference system (ANFIS) for concentration estimation of volatile organic compounds (VOCs) by analyzing response matrix of polymer-functionalized surface acoustic wave (SAW) sensor array. The performance of ANFIS is compared with that of subtractive clustering based fuzzy inference system (SC-FIS) and backpropagation artificial neural network (BP-ANN). For analysis, the raw SAW sensor array data is preprocessed by logarithmic scaling followed by dimensional autoscaling and the feature extraction by principal component analysis (PCA). For concentration prediction, the extracted feature vectors were fed as input to the three methods (ANFIS, SC-FIS and BP-ANN) independently. The performance of the three methods were evaluated on the basis of root mean square error (RMSE) and correlation value involving actual and estimated values of concentration. Five sets of SAW sensor array responses are analyzed. The analysis includes both experimental and synthetic (sensor model generated) data sets. It is found that the ANFIS has the least value of RMSE and highest value of correlation compared to SC-FIS and BP-ANN. This signifies the relative superiority of ANFIS method.     

傅立叶变换红外光谱及其图像技术在生物医学中的应用

本文介绍傅立叶变换红外光谱分析技术在蛋白质、核酸、细菌和药物等领域中的应用和红外图像技术在生物细胞、组织的成分及化学结构分析等中的应用。     

油气水三相流产出剖面光纤持气率计响应规律的实验研究

为进一步研究油气水三相流产出剖面测井中光纤持气率计在高含水情况下的响应规律,在大庆油田多相流实验装置上进行了动态实验研究。实验结果表明,当油的流量一定,高含水的情况下,气量在5~10m3/d变化时测量持气率值与实际持气率值之间误差变化较大。气量大于10m3/d时误差变化较小,说明该仪器适合测量气量在10m3/d以上的混合流体。此结果对光纤持气率计的进一步优化设计提供了实验依据。     

电站锅炉对流烟道烟温声学监测技术关键

针对电站锅炉过热器、再热器超温问题,拟采用声学测温对流烟道烟气侧温度进行实时在线监测。搭建管阵列实验台,在实验室环境下研究管阵列对声波传播的影响。在锅炉现场环境下,利用人孔安装声学测点,对锅炉热态时对流烟道烟气温度进行监测,验证声学方法的可行性。结果表明,声波信号大部分可以透过管阵列传播过来。在管阵列环境下,声波飞渡时间可以由广义互相关时间延迟估计获得。声学法可以用来进行对流烟道内实际烟气温度的测量。     

Effect of fuzzy C means technique in failure mode discrimination of glass/epoxy laminates using acoustic emission monitoring

Acoustic emission is one of the powerful techniques that can be used for in situ structural health monitoring of composite laminates. One of the main issues of AE is to characterize the different damage mechanisms from the detected AE signals. Unsupervised Pattern recognition has been one of the techniques used for the identification of a specific failure mode in composites from Acoustic emission data. Cross ply composite laminate of size 300 × 300 mm is fabricated using Vacuum bag molding. ASTM D3039 Standard tensile specimens are cut from the laminate and these specimens are subjected to uni axial tensile test under Acoustic Emission monitoring. Fast Fourier transform analysis (FFT) and Short Time Fast Fourier Transform (STFFT) analysis are performed on the Wave forms of the AE hit data obtained during the conduct of tensile test to characterize the failure modes in crossply specimens. Fast Fourier Transform enabled calculating the frequency content of each damage mechanism. In this paper Fuzzy C Mean clustering is performed for the AE parameters obtained from the test and the efficiency of this technique is being investigated using FFT AND STFFT analysis.