Sixteen indole derivatives have been computed at B3LYP/6-31 IG^＊＊ level using density functional theory （DFF）. Based on linear solvation energy theory, the structural parameters were employed to present correlatio...Sixteen indole derivatives have been computed at B3LYP/6-31 IG^＊＊ level using density functional theory （DFF）. Based on linear solvation energy theory, the structural parameters were employed to present correlation between the parameters of chromatograph capacity factor （CCF） and molecular structural parameters. As a result, the correlation equation of the reversed phased high performance liquid chromatograph capacity factor to the intercept lgk＇w and slope S of CCF were obtained, from which the correlation coefficients of lgk＇w to the structural parameters are r^2 = 0.9596 and q^2 = 0.9262. While the correlation coefficients of the parameter S r^2 q^2 with structures are = 0.9750 and = 0.9252. Moreover, the effect of water as solvent on the present two models was also considered using SCRF method, and the result shows that the predicting capacity of correlation equation of lgkw＇ increases, while that of the model for S decreases slightly. Both two correlation equations achieved in this work are more advantageous than those using theoretical descriptors from molecular connectivity indices.展开更多
The chroma difference(DC) and lightness difference (DL) of 288 jadeite-jades with fine texture and even green color have been analyzed based on color difference formula CIE LAB in the uniform color space CIE 1976 L^~*...The chroma difference(DC) and lightness difference (DL) of 288 jadeite-jades with fine texture and even green color have been analyzed based on color difference formula CIE LAB in the uniform color space CIE 1976 L^~*a^~*b^~* to evaluate their contribution to the color appearance and color difference(DE).The analysis of lightness(L^~*), chroma(C^~*) and hue-angle(h_o) show that the vivid yellowish green color occurs when L^~*∈5.29-59.2,展开更多
The present paper covers the actional mechanism of trifluoroacetic acid for the separation of biopolymers investigated by using the parameters of stoichiometric displacement model for retention(SDM-R) in reversed-phas...The present paper covers the actional mechanism of trifluoroacetic acid for the separation of biopolymers investigated by using the parameters of stoichiometric displacement model for retention(SDM-R) in reversed-phase liquid chromatography. It was found that the trifluoroacetic acid(TFA) may participate in, or stimulate the association among displacing agent molecules in mobile phase, and decrease the affinity of both the associate molecules of the displacing agent and the TFA-protein ion-pairing. The former dominates over the separation selectivity of biopolymers as the concentration of TFA is lower than a given value, and the two contrary functions partly offset to each other and the latter dominates as its concentration is greater than the given value.展开更多
土遗址夯筑支顶加固外观多以目测评价协调性,受观测者主观影响较大.因此,量化评价已成为土遗址加固效果评价的关键问题,其中色度是重要的量化指标.为有效提高夯筑支顶体表面色度检测的准确性与科学性,通过检测不同颜色比例混合土试样的...土遗址夯筑支顶加固外观多以目测评价协调性,受观测者主观影响较大.因此,量化评价已成为土遗址加固效果评价的关键问题,其中色度是重要的量化指标.为有效提高夯筑支顶体表面色度检测的准确性与科学性,通过检测不同颜色比例混合土试样的色度,确定人体能认别土体色差ΔE的极限为3.62~4.08,提出了色度差界限ΔE=4为土遗址夯筑支顶体色差质量控制临界值.通过现场测试发现,露天光线、边缘漏光、测试点凸凹不平均影响测试结果;光照环境与边缘漏光影响极小,当检测位置凹陷深度大于5 mm、面积大于50 mm 2时,色度检测将出现较大偏差.为此本研究提出了夯土遗址色度检测的限定条件,为土遗址规范化保护提供理论和技术支撑.展开更多
基金This work was supported by the National Basic Research Program of China (2003CB415002) and the China Postdoctoral Science Foundation (No. 2003033486) and the Natural Science Research Fund of University in Jiangsu (04KJB150149)
文摘Sixteen indole derivatives have been computed at B3LYP/6-31 IG^＊＊ level using density functional theory （DFF）. Based on linear solvation energy theory, the structural parameters were employed to present correlation between the parameters of chromatograph capacity factor （CCF） and molecular structural parameters. As a result, the correlation equation of the reversed phased high performance liquid chromatograph capacity factor to the intercept lgk＇w and slope S of CCF were obtained, from which the correlation coefficients of lgk＇w to the structural parameters are r^2 = 0.9596 and q^2 = 0.9262. While the correlation coefficients of the parameter S r^2 q^2 with structures are = 0.9750 and = 0.9252. Moreover, the effect of water as solvent on the present two models was also considered using SCRF method, and the result shows that the predicting capacity of correlation equation of lgkw＇ increases, while that of the model for S decreases slightly. Both two correlation equations achieved in this work are more advantageous than those using theoretical descriptors from molecular connectivity indices.
文摘The chroma difference(DC) and lightness difference (DL) of 288 jadeite-jades with fine texture and even green color have been analyzed based on color difference formula CIE LAB in the uniform color space CIE 1976 L^~*a^~*b^~* to evaluate their contribution to the color appearance and color difference(DE).The analysis of lightness(L^~*), chroma(C^~*) and hue-angle(h_o) show that the vivid yellowish green color occurs when L^~*∈5.29-59.2,
基金Supported by the National Natrual Science Foundation of China
文摘The present paper covers the actional mechanism of trifluoroacetic acid for the separation of biopolymers investigated by using the parameters of stoichiometric displacement model for retention(SDM-R) in reversed-phase liquid chromatography. It was found that the trifluoroacetic acid(TFA) may participate in, or stimulate the association among displacing agent molecules in mobile phase, and decrease the affinity of both the associate molecules of the displacing agent and the TFA-protein ion-pairing. The former dominates over the separation selectivity of biopolymers as the concentration of TFA is lower than a given value, and the two contrary functions partly offset to each other and the latter dominates as its concentration is greater than the given value.
文摘土遗址夯筑支顶加固外观多以目测评价协调性,受观测者主观影响较大.因此,量化评价已成为土遗址加固效果评价的关键问题,其中色度是重要的量化指标.为有效提高夯筑支顶体表面色度检测的准确性与科学性,通过检测不同颜色比例混合土试样的色度,确定人体能认别土体色差ΔE的极限为3.62~4.08,提出了色度差界限ΔE=4为土遗址夯筑支顶体色差质量控制临界值.通过现场测试发现,露天光线、边缘漏光、测试点凸凹不平均影响测试结果;光照环境与边缘漏光影响极小,当检测位置凹陷深度大于5 mm、面积大于50 mm 2时,色度检测将出现较大偏差.为此本研究提出了夯土遗址色度检测的限定条件,为土遗址规范化保护提供理论和技术支撑.
