目的通过测定白芷传统饮片中总香豆素、欧前胡素、异欧前胡素的含量,了解其在治疗白癜风中的作用和用量。方法采用紫外-可见分光光度法测定白芷总香豆素的含量,采用高效液相色谱法同时测定欧前胡素、异欧前胡素含量,XB-C18分析柱(4.6 mm...目的通过测定白芷传统饮片中总香豆素、欧前胡素、异欧前胡素的含量,了解其在治疗白癜风中的作用和用量。方法采用紫外-可见分光光度法测定白芷总香豆素的含量,采用高效液相色谱法同时测定欧前胡素、异欧前胡素含量,XB-C18分析柱(4.6 mm×250 mm,5μm),流动相组成为甲醇和水(70:30),流速1 m L·min-1,检测波长300 nm,流速1.0 m L·min-1。结果欧前胡素、异欧前胡素在范围内线性良好。结论本法简便、快速、准确,可用于白芷中欧前胡素与异欧前胡素的含量测定,为白芷在治疗白癜风中的作用和用量提供参考依据。展开更多
This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 1...This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 10^-6 cm^2/W induced by thermo-optical effect is obtained. It indicates that the sample has excellent optical non- linear properties. The physical mechanism of the great nonlinear optical effect is analysed and the optical conjugate characteristic is also discussed with degenerate four-wave-mixing. The phase conjugate wave diffracted from the formative refractive index grating in the sample is acquired and its equivalent reflectivity reaches about 22%. On this basis, the reflective wave phase-conjugated mirror system was designed, and the image aberration experienced in propagation in the storage experiment is corrected by using the system.展开更多
文摘目的通过测定白芷传统饮片中总香豆素、欧前胡素、异欧前胡素的含量,了解其在治疗白癜风中的作用和用量。方法采用紫外-可见分光光度法测定白芷总香豆素的含量,采用高效液相色谱法同时测定欧前胡素、异欧前胡素含量,XB-C18分析柱(4.6 mm×250 mm,5μm),流动相组成为甲醇和水(70:30),流速1 m L·min-1,检测波长300 nm,流速1.0 m L·min-1。结果欧前胡素、异欧前胡素在范围内线性良好。结论本法简便、快速、准确,可用于白芷中欧前胡素与异欧前胡素的含量测定,为白芷在治疗白癜风中的作用和用量提供参考依据。
基金Project supported by the National Natural Science Foundation of China （Grant Nos 19834030 and 50533010）.
文摘This paper reports that the nonlinear refractive index of a novel organic optical storage film doped azodiphenylamine polymer is measured by using the Z-scan technique. The nonlinear refractive index up to 3.7× 10^-6 cm^2/W induced by thermo-optical effect is obtained. It indicates that the sample has excellent optical non- linear properties. The physical mechanism of the great nonlinear optical effect is analysed and the optical conjugate characteristic is also discussed with degenerate four-wave-mixing. The phase conjugate wave diffracted from the formative refractive index grating in the sample is acquired and its equivalent reflectivity reaches about 22%. On this basis, the reflective wave phase-conjugated mirror system was designed, and the image aberration experienced in propagation in the storage experiment is corrected by using the system.
文摘以芒草为原料,用Na OH/H_2O_2溶液体系预处理制备芒草纤维,在冰醋酸环境下,以浓硫酸为催化剂与醋酸酐酯化制备芒草醋酸纤维素。优化了预处理条件:温度、时间、次数和酯化条件:催化剂量、温度、时间、醋酸酐量,最佳条件下制备出的芒草纤维的纤维素、半纤维素和木质素的质量分数分别为75.3%、17.3%、5.1%,制备出芒草醋酸纤维素的取代度DS=2.8,特性黏度[η]=1.24 d L/g,达到美国联邦贸易委员会指南认定的三醋酸纤维素标准。利用扫描电镜(SEM)和热分析(TG、DSC)对制得样品进行表征。结果表明,可以利用Na OH/H_2O_2水溶液体系预处理芒草原料制备芒草纤维,并进一步酯化制备出高取代度的醋酸纤维素。
