建立紫外-可见-短波近红外漫反射光谱结合化学计量学测定白芷中二氧化硫残留量的方法。利用紫外-可见-短波近红外漫反射光谱技术并结合化学计量学建模预测二氧化硫残留量。偏最小二乘回归法(PLSR)建模优于支持向量回归法(SVR); Random F...建立紫外-可见-短波近红外漫反射光谱结合化学计量学测定白芷中二氧化硫残留量的方法。利用紫外-可见-短波近红外漫反射光谱技术并结合化学计量学建模预测二氧化硫残留量。偏最小二乘回归法(PLSR)建模优于支持向量回归法(SVR); Random Frog波段选择结合Auto-scaling预处理后PLS建模后预测效果最佳,校正集R^2为0. 99,交叉验证集R^2为0. 94,预测集R^2为0. 96。紫外-可见-短波近红外漫反射光谱结合化学计量学可以实现二氧化硫残留量的快速检测,为中药饮片的质量评价及监管提供一种技术手段。展开更多
Molecular structure of PdH2 and YH2 and their thermodynamic functions(H,S,G) at different temperature had been calculated using density functional theory B3LYP method,and the standard formed thermodynamic functions(Δ...Molecular structure of PdH2 and YH2 and their thermodynamic functions(H,S,G) at different temperature had been calculated using density functional theory B3LYP method,and the standard formed thermodynamic functions(ΔH°,ΔS°,ΔG°) for PdH2 and YH2 molecules had also been calculated by thermodynamic method.The results showed that PdH2 and YH2 molecules have thermodynamic stability below 598 K and 698 K,respeetively.展开更多
文摘Molecular structure of PdH2 and YH2 and their thermodynamic functions(H,S,G) at different temperature had been calculated using density functional theory B3LYP method,and the standard formed thermodynamic functions(ΔH°,ΔS°,ΔG°) for PdH2 and YH2 molecules had also been calculated by thermodynamic method.The results showed that PdH2 and YH2 molecules have thermodynamic stability below 598 K and 698 K,respeetively.
