目的采用化学计量学结合灰色关联度—逼近理想解排序(technique for order preference by similarity to an ideal solution,TOPSIS)法模型建立综合评价知母药材质量的方法。方法建立高效液相色谱法(high performance liquid chromatogr...目的采用化学计量学结合灰色关联度—逼近理想解排序(technique for order preference by similarity to an ideal solution,TOPSIS)法模型建立综合评价知母药材质量的方法。方法建立高效液相色谱法(high performance liquid chromatography,HPLC)黄酮特征图谱及水分、总黄酮、总皂苷含量测定方法,采用聚类分析(hierarchical cluster analysis,HCA)、主成分分析(principal component analysis,PCA)和正交偏最小二乘法—判别分析(orthogonal partial least squares-discriminant analysis,OPLS-DA)对不同批次知母样品进行化学计量学分析,利用熵权法结合灰色关联度—TOPSIS构建知母药材质量评价模型。结果建立的知母黄酮特征图谱、含量测定方法稳定、可靠;HCA、PCA和OPLS-DA可将10批知母样品分为2类;灰色关联度—TOPSIS模型综合得分显示,S10号知母样品质量较好,评分靠前。结论所建立的特征图谱结合化学计量学与灰色关联度—TOPSIS分析方法,能客观评价不同批次知母药材质量,为中药质量综合评价与控制的方法学建立提供参考。展开更多
Bismuth tellurite Bi 2TeO 5 is a novel nonlinear crystal with interesting physical properties.The crystal structure belongs to the mm 2 symmetry and can be described as 2 3 1 fluorite type superstructure,derived from ...Bismuth tellurite Bi 2TeO 5 is a novel nonlinear crystal with interesting physical properties.The crystal structure belongs to the mm 2 symmetry and can be described as 2 3 1 fluorite type superstructure,derived from a hypothetically ordered totally oxidized Bi 2TeO 6 structure.The lattice contains 17% open oxygen positions and cation coordination sites between 5 and 8.The material,therefore is an excellent host for several dopants with segregation coefficients close to unity.The most interesting feature of the crystal is a long living(years)photorefractive signal that developed in the four wave mixing process without specific fixing.This feature enables the application of the crystal as hologram recording material. Single crystals of Bi 2TeO 5 can be grown by the Czochralski method.One of the key problem of the growth process is the control of the stoichiometry of the crystals.The high vapor pressure of TeO 2 at the melting point results in the nonstoichiometric evaporation of the melt and by altering the initial Bi 2O 3/TeO 2 creates continuously shifted melt composition.Between 550℃ and 700℃ the oxidation state of Bi 2TeO 5 may be modified,since the fully oxidized Bi 2TeO 6 compound is thermodynamically stable in this range.Crystals grown from the melt at 906℃,depending on the post growth period(annealing and cooling down processes)might be partly or fully oxidized.展开更多
文摘目的采用化学计量学结合灰色关联度—逼近理想解排序(technique for order preference by similarity to an ideal solution,TOPSIS)法模型建立综合评价知母药材质量的方法。方法建立高效液相色谱法(high performance liquid chromatography,HPLC)黄酮特征图谱及水分、总黄酮、总皂苷含量测定方法,采用聚类分析(hierarchical cluster analysis,HCA)、主成分分析(principal component analysis,PCA)和正交偏最小二乘法—判别分析(orthogonal partial least squares-discriminant analysis,OPLS-DA)对不同批次知母样品进行化学计量学分析,利用熵权法结合灰色关联度—TOPSIS构建知母药材质量评价模型。结果建立的知母黄酮特征图谱、含量测定方法稳定、可靠;HCA、PCA和OPLS-DA可将10批知母样品分为2类;灰色关联度—TOPSIS模型综合得分显示,S10号知母样品质量较好,评分靠前。结论所建立的特征图谱结合化学计量学与灰色关联度—TOPSIS分析方法,能客观评价不同批次知母药材质量,为中药质量综合评价与控制的方法学建立提供参考。
文摘Bismuth tellurite Bi 2TeO 5 is a novel nonlinear crystal with interesting physical properties.The crystal structure belongs to the mm 2 symmetry and can be described as 2 3 1 fluorite type superstructure,derived from a hypothetically ordered totally oxidized Bi 2TeO 6 structure.The lattice contains 17% open oxygen positions and cation coordination sites between 5 and 8.The material,therefore is an excellent host for several dopants with segregation coefficients close to unity.The most interesting feature of the crystal is a long living(years)photorefractive signal that developed in the four wave mixing process without specific fixing.This feature enables the application of the crystal as hologram recording material. Single crystals of Bi 2TeO 5 can be grown by the Czochralski method.One of the key problem of the growth process is the control of the stoichiometry of the crystals.The high vapor pressure of TeO 2 at the melting point results in the nonstoichiometric evaporation of the melt and by altering the initial Bi 2O 3/TeO 2 creates continuously shifted melt composition.Between 550℃ and 700℃ the oxidation state of Bi 2TeO 5 may be modified,since the fully oxidized Bi 2TeO 6 compound is thermodynamically stable in this range.Crystals grown from the melt at 906℃,depending on the post growth period(annealing and cooling down processes)might be partly or fully oxidized.
