应用近红外光谱分析技术（Near infrared spectroscopy，NIRS）和偏最小二乘法（Partial least squares，PLS）建立棉粕中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）定量分析模型，并对模型优化方法进行研究。模型的交叉验证决定系数（R^...应用近红外光谱分析技术（Near infrared spectroscopy，NIRS）和偏最小二乘法（Partial least squares，PLS）建立棉粕中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）定量分析模型，并对模型优化方法进行研究。模型的交叉验证决定系数（R^2ev）分别为0．94和0．95；交叉验证标准差（RMSECV）分别为0．668和0．441；模型外部验证决定系数（R^2val）分别为0．95和0．92；外部验证标准差（RMSEP）分别为0．81和0．44。结果表明：近红外光谱法可用于棉粕中NDF和ADF含量的快速测量。建模过程中选取有效的光谱区间可以提高模型的稳健性。展开更多
The adjustable parameters in the popular conductor-like screening model for real solvents(COSMO-RS)within the Amsterdam density functional(ADF)framework have been re-optimized to fit for the systems containing ionic l...The adjustable parameters in the popular conductor-like screening model for real solvents(COSMO-RS)within the Amsterdam density functional(ADF)framework have been re-optimized to fit for the systems containing ionic liquids(ILs).To get the optimal values of misfit energy constant a^0,hydrogen bond coefficient c_(hb)and effective contact surface area of a segment a_(eff),2283 activity coefficient data points at infinite dilution and 1433 CO_2 solubility data points exhaustively collected from references were used as training set.The average relative deviations(ARDs)of activity coefficients at infinite dilution and CO_2 solubility between experimental data and predicted values are 32.22%and17.61%,respectively,both of which are significantly lower than the original COSMO-RS versions.Predictions for other activity coefficients of solutes in ILs,solubility data of CO_2 in pure ILs and the binary mixtures of ILs at either high or low temperatures,and vapor–liquid equilibrium(VLE)for binary systems involving ILs have also been performed to demonstrate the validity of the parameterization of COSMO-RS model for ILs.The results showed that the predicted results by COSMO-RS model with the new optimized parameters are in much better agreement with experimental data than those by the original versions over a wide temperature and pressure range.The COSMO-RS model for ILs presented in this work improves the prediction accuracy of thermodynamic properties for the systems containing ILs,which is always highly desirable for general chemical engineers.展开更多
对强磁场装置电源所需的有源直流滤波器ADF(Active DC Filter)进行了设计,利用脉宽调制(PWM)及并联有源滤波技术提出了新的滤波方案。给出了系统结构并对工作原理进行了说明,论述了该系统的设计方法。根据其实际负载特性,通过检测负载...对强磁场装置电源所需的有源直流滤波器ADF(Active DC Filter)进行了设计,利用脉宽调制(PWM)及并联有源滤波技术提出了新的滤波方案。给出了系统结构并对工作原理进行了说明,论述了该系统的设计方法。根据其实际负载特性,通过检测负载端电压,利用电流的PWM控制技术产生所需电流,通过对负载侧的滤波电容进行充、放电调整负载端电压,从而实现负载电流的低纹波。基于传递函数建立了该系统的数学模型,并对控制系统进行了详细的分析,分析表明该系统具有良好的快速跟踪性能及对谐波很好的抑制效果。最后,给出了仿真结果,验证了该有源滤波器的良好性能,尤其对低次谐波的抑制更为明显。展开更多
文摘应用近红外光谱分析技术（Near infrared spectroscopy，NIRS）和偏最小二乘法（Partial least squares，PLS）建立棉粕中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）定量分析模型，并对模型优化方法进行研究。模型的交叉验证决定系数（R^2ev）分别为0．94和0．95；交叉验证标准差（RMSECV）分别为0．668和0．441；模型外部验证决定系数（R^2val）分别为0．95和0．92；外部验证标准差（RMSEP）分别为0．81和0．44。结果表明：近红外光谱法可用于棉粕中NDF和ADF含量的快速测量。建模过程中选取有效的光谱区间可以提高模型的稳健性。
基金financially supported by the National Natural Science Foundation of China under Grants (Nos. 21476009, 21406007 and U1462104)
文摘The adjustable parameters in the popular conductor-like screening model for real solvents(COSMO-RS)within the Amsterdam density functional(ADF)framework have been re-optimized to fit for the systems containing ionic liquids(ILs).To get the optimal values of misfit energy constant a^0,hydrogen bond coefficient c_(hb)and effective contact surface area of a segment a_(eff),2283 activity coefficient data points at infinite dilution and 1433 CO_2 solubility data points exhaustively collected from references were used as training set.The average relative deviations(ARDs)of activity coefficients at infinite dilution and CO_2 solubility between experimental data and predicted values are 32.22%and17.61%,respectively,both of which are significantly lower than the original COSMO-RS versions.Predictions for other activity coefficients of solutes in ILs,solubility data of CO_2 in pure ILs and the binary mixtures of ILs at either high or low temperatures,and vapor–liquid equilibrium(VLE)for binary systems involving ILs have also been performed to demonstrate the validity of the parameterization of COSMO-RS model for ILs.The results showed that the predicted results by COSMO-RS model with the new optimized parameters are in much better agreement with experimental data than those by the original versions over a wide temperature and pressure range.The COSMO-RS model for ILs presented in this work improves the prediction accuracy of thermodynamic properties for the systems containing ILs,which is always highly desirable for general chemical engineers.
文摘对强磁场装置电源所需的有源直流滤波器ADF(Active DC Filter)进行了设计,利用脉宽调制(PWM)及并联有源滤波技术提出了新的滤波方案。给出了系统结构并对工作原理进行了说明,论述了该系统的设计方法。根据其实际负载特性,通过检测负载端电压,利用电流的PWM控制技术产生所需电流,通过对负载侧的滤波电容进行充、放电调整负载端电压,从而实现负载电流的低纹波。基于传递函数建立了该系统的数学模型,并对控制系统进行了详细的分析,分析表明该系统具有良好的快速跟踪性能及对谐波很好的抑制效果。最后,给出了仿真结果,验证了该有源滤波器的良好性能,尤其对低次谐波的抑制更为明显。
