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81.
Eric R. MacamAuthor VitaeBryan M. BlackburnAuthor Vitae Eric D. WachsmanAuthor Vitae 《Sensors and actuators. B, Chemical》2011,158(1):304-312
The intent of this work is to look at the effects of varying the La2CuO4 electrode area and the asymmetry between the sensing and counter electrode in a solid state potentiometric sensor with respect to NOx sensitivity. NO2 sensitivity was observed at 500-600 °C with a maximum sensitivity of ∼22 mV/decade [NO2] observed at 500 °C for the sensor with a La2CuO4 electrode area of ∼30 mm2. The relationship between NO2 sensitivity and area is nearly parabolic at 500 °C, decreases linearly with increasing electrode area at 600 °C, and was a mixture of parabolic and linear behavior 550 °C. NO sensitivity varied non-linearly with electrode area with a minima (maximum sensitivity) of ∼−22 mV/decade [NO] at 450 °C for the sensor with a La2CuO4 electrode area of 16 mm2. The behavior at 400 °C was similar to that of 450 °C, but with smaller sensitivities due to a saturation effect. At 500 °C, NO sensitivity decreases linearly with area.We also used electrochemical impedance spectroscopy (EIS) to investigate the electrochemical processes that are affected when the sensing electrode area is changed. Changes in impedance with exposure to NOx were attributed to either changes in La2CuO4 conductivity due to gas adsorption (high frequency impedance) or electrocatalysis occurring at the electrode/electrolyte interface (total electrode impedance). NO2 caused a decrease in high frequency impedance while NO caused an increase. In contrast, NO2 and NO both caused a decrease in the total electrode impedance. The effect of area on both the potentiometric and impedance responses show relationships that can be explained through the mechanistic contributions included in differential electrode equilibria. 相似文献
82.
利用当今主流的组网技术、网络安全技术、主机技术及存储备份技术,结合以应用为导向的设计思想,对某市美术馆计算机信息网络系统进行了方案设计。整个设计采用分功能区模块化的设计方法,具有贯穿整体的集成性、扩展性、兼容性。 相似文献
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数列极限是一类重要的极限,在经济和数学领域中发挥着重要的作用。以举例的方式介绍数列极限在现实生活中的应用,包括几何中计算曲线所围图形的面积.求二次方程的数值解,购房按揭贷款分期还款问题,及连续复利问题。 相似文献
86.
Reprocessing the MODIS Leaf Area Index products for land surface and climate modelling 总被引:3,自引:0,他引:3
Land surface and climate modelling requires continuous and consistent Leaf Area Index (LAI). High spatiotemporal resolution and long-time record data are more in demand nowadays and will continue to be in the future. MODIS LAI products meet these requirements to some degree. However, due to the presence of cloud and seasonal snow cover, the instrument problems and the uncertainties of retrieval algorithm, the current MODIS LAI products are spatially and temporally discontinuous and inconsistent, which limits their application in land surface and climate modelling. To improve the MODIS LAI products on a global scale, we considered the characteristics of the MODIS LAI data and made the best use of quality control (QC) information, and developed an integrated two-step method to derive the improved MODIS LAI products effectively and efficiently on a global scale. First, we used the modified temporal spatial filter (mTSF) method taking advantage of background values and QC information at each pixel to do a simple data assimilation for relatively low quality data. Then we applied the post processing-TIMESAT (A software package to analyze time-series of satellite sensor data) Savitzky-Golay (SG) filter to get the final result. We implemented the method to 10 years of the MODIS Collection 5 LAI data. In comparison with the LAI reference maps and the MODIS LAI data, our results showed that the improved MODIS LAI data are closer to the LAI reference maps in magnitude and also more continuous and consistent in both time-series and spatial domains. In addition, simple statistics were used to evaluate the differences between the MODIS LAI and the improved MODIS LAI. 相似文献
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从管理角度介绍了典型的光纤通道局域网(Fibre Channel Storage Area Network,以下简称FC_SAN)环境,并阐述了管理该环境所面临的问题。同时,提出了一种局域网(Storage Area Network,以下简称SAN)管理体系,该体系分为两层,分别提供面向对象的服务和与实体相关的服务。 相似文献
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本文简要介绍了SW-CMM的产生、基本概念与精髓、用途、评估概况,实施CMM的价值,CMM与CSCMM、ISO9001的比较,以及CMM的学习应用和评估的浅见。 相似文献
90.
ZHU Xue-long 《数字社区&智能家居》2008,(5)
局域网是信息化网络不可分割的重要组成部分,其后台服务优化和安全配置是发挥其功能作用的关键。本文注重从终端客户机上配合服务器着手,综合服务功能的启动选择和安全设置法、组策略法、端口关闭法四个方面详细论述局域网服务优化和安全配置。 相似文献