将连续变化的碰撞能量与串联质谱相结合,建立了能量分辨质谱(Energy-resolved mass spectrometry,ERMS)分析方法用以区分和检测人参皂苷同分异构体20(S)-Rf和Rg_(1).ERMS将子离子与母离子强度的比值定义为强度分数(Intensity fraction,I...将连续变化的碰撞能量与串联质谱相结合,建立了能量分辨质谱(Energy-resolved mass spectrometry,ERMS)分析方法用以区分和检测人参皂苷同分异构体20(S)-Rf和Rg_(1).ERMS将子离子与母离子强度的比值定义为强度分数(Intensity fraction,IF),两个子离子强度的比值定义为强度比(Intensity ratio,IR),并通过IF和IR分别对连续变化的碰撞能量作图建立特征碎片离子的IF和IR曲线.虽然20(S)-Rf和Rg_(1)的串联质谱图无明显差异,但是多元统计分析结果显示其特征碎片离子[M-Glc-H]-,[M-2Glc-H]-和[M-2Glc-C_(6)H_(12)-H]-的IF和IR曲线差异显著,有明显的区分边界,可以直接区分20(S)-Rf和Rg_(1).进一步利用ERMS实时分析了原人参三醇型皂苷生物转化产物中20(S)-Rf和Rg_(1)的相对摩尔含量.结果表明,ERMS不需液相色谱分离即可实现20(S)-Rf和Rg_(1)的快速区分和相对含量检测.展开更多
This paper identifies the shortcomings of variance and semi-variance methods in investment risk measurement and introduces a new model,namely RR-ER (relative risk and excess revenue) model,which takes account of the r...This paper identifies the shortcomings of variance and semi-variance methods in investment risk measurement and introduces a new model,namely RR-ER (relative risk and excess revenue) model,which takes account of the revenue over expectation problem.Properties of RR-ER model and the consistency between RR-ER model and traditional risk measure model with regard to continuous random variables are discussed.Case analysis is presented to prove the practicality and efficiency of this new method.展开更多
The efficiency of any organizations at manufacturing sector or service sector, profit making or non-profit making, is most important factor for survival and growth of the organization. The Data Envelopment Analysis （...The efficiency of any organizations at manufacturing sector or service sector, profit making or non-profit making, is most important factor for survival and growth of the organization. The Data Envelopment Analysis （DEA） technique is one of the most popular and effective tool to measure relative efficiency hence is appropriate to make comparison among similar organizations with multiple output and input. This study performs frontier analysis and measures the relative efficiency of Nepalese commercial banks using DEA approach with two output and two input variables.展开更多
文摘将连续变化的碰撞能量与串联质谱相结合,建立了能量分辨质谱(Energy-resolved mass spectrometry,ERMS)分析方法用以区分和检测人参皂苷同分异构体20(S)-Rf和Rg_(1).ERMS将子离子与母离子强度的比值定义为强度分数(Intensity fraction,IF),两个子离子强度的比值定义为强度比(Intensity ratio,IR),并通过IF和IR分别对连续变化的碰撞能量作图建立特征碎片离子的IF和IR曲线.虽然20(S)-Rf和Rg_(1)的串联质谱图无明显差异,但是多元统计分析结果显示其特征碎片离子[M-Glc-H]-,[M-2Glc-H]-和[M-2Glc-C_(6)H_(12)-H]-的IF和IR曲线差异显著,有明显的区分边界,可以直接区分20(S)-Rf和Rg_(1).进一步利用ERMS实时分析了原人参三醇型皂苷生物转化产物中20(S)-Rf和Rg_(1)的相对摩尔含量.结果表明,ERMS不需液相色谱分离即可实现20(S)-Rf和Rg_(1)的快速区分和相对含量检测.
文摘This paper identifies the shortcomings of variance and semi-variance methods in investment risk measurement and introduces a new model,namely RR-ER (relative risk and excess revenue) model,which takes account of the revenue over expectation problem.Properties of RR-ER model and the consistency between RR-ER model and traditional risk measure model with regard to continuous random variables are discussed.Case analysis is presented to prove the practicality and efficiency of this new method.
文摘The efficiency of any organizations at manufacturing sector or service sector, profit making or non-profit making, is most important factor for survival and growth of the organization. The Data Envelopment Analysis （DEA） technique is one of the most popular and effective tool to measure relative efficiency hence is appropriate to make comparison among similar organizations with multiple output and input. This study performs frontier analysis and measures the relative efficiency of Nepalese commercial banks using DEA approach with two output and two input variables.
