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羧酸类化合物pKa的定量构效关系研究 总被引：1，自引：0，他引：1
对38种有机一元羧酸的电拓扑状态指数(En)及价分子连接性指数(mxv)进行了计算,建立了有机羧酸pKa与拓扑指数的数学模型。最佳七元回归模型为:pKa=6.276 2.395E8-0.470E39-0.171E38 10.102E6-0.732E40-0.189E17 1.8524xv其R=0.967,s=0.3005,优于文献研究结果。通过Jackknife法检验该模型具有总体稳健性。结果表明,电拓扑指数和价分子连接性指数能够较好表征分子结构特征,能有效揭示影响羧酸pKa的本质因素。 相似文献
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Stephen Hackney 《文物保护研究》2016,61(1):55-69
Acid-detector (A-D) strips were originally developed to assess the deterioration of acetate film stock, but they can also be used more generally within enclosures to detect volatile acidic pollution. A hand-held reflectance spectrophotometer was used to record the colour of individual strips in order to make consistent and reproducible readings. Calibration was carried out using the yellow-blue axis b*(D65) value in the CIELAB1976 system to measure the colour of A-D strips suspended in enclosed containers over solutions of acetic acid in combinations with glycerol to control the relative humidity (RH). A-D strips were found to be sensitive to changes in high RH (60–90%) but affected little by changes in lower RH or temperatures in the museum display and storage range. A-D strips can be used to establish the presence of volatile acids, record the indication of acid vapour concentration, explore conditions within a container, and to find sources of volatile acidity. They respond very quickly and several can be placed around an object. They therefore show promise for measuring slowly changing conditions, such as seasonal changes and the gradual accumulation of acidity in poorly ventilated containers and spaces. A-D strips proved useful in assessing air quality in storage and display enclosures. Examples and test results are presented. Well-sealed plywood transit frames and storage cases were found to be most polluted with volatile acids. Storage rooms with air filtration systems but filled with wooden objects had significantly reduced air quality. 相似文献
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