Lack of up-to-date information on efficient operation and maintenance of EPDS （electric power distribution systems）, Nigeria is addressed by designing and implementing an indigenous real-time monitoring and diagnosi...Lack of up-to-date information on efficient operation and maintenance of EPDS （electric power distribution systems）, Nigeria is addressed by designing and implementing an indigenous real-time monitoring and diagnosis system. The system encompasses the development of software driven hardware positioned at the remotely located sub-stations at the low voltage level to keep track of the network in real-time. The detection of faults exploits threshold passing algorithm through continuous monitoring of the network power quality. Communication between the RTU （remote terminal unit） and the DCC （distribution control center） which is based on GSM is initiated by disturbance. The DCC performs fault evaluation processing using the received data and predetermined faults signatures to determine the nature of disturbance and presents the result in graphic user interface environment. A fault reporting time of 2 s was achieved. The developed system exhibits a high degree of accuracy and manifests no spurious reports during testing. The resultant system limits the effects of interruption and increases power availability by reducing the down time. The system strengthens engineering and management capabilities required to enhance reliability by providing information about the network health status.展开更多
Objectives:This study is aimed to explore the blending process of Dahuang soda tablets.These are composed of two active pharmaceutical ingredients(APIs,emodin and emodin methyl ether)and four kinds of excipients(sodiu...Objectives:This study is aimed to explore the blending process of Dahuang soda tablets.These are composed of two active pharmaceutical ingredients(APIs,emodin and emodin methyl ether)and four kinds of excipients(sodium bicarbonate,starch,sucrose,and magnesium stearate).Also,the objective is to develop a more robust model to determine the blending end-point.Methods:Qualitative and quantitative methods based on near-infrared(NIR)spectroscopy were established to monitor the homogeneity of the powder during the blending process.A calibration set consisting of samples from 15 batches was used to develop two types of calibration models with the partial least squares regression(PLSR)method to explore the influence of density on the model robustness.The principal component analysis-moving block standard deviation(PCA-MBSD)method was used for the end-point determination of the blending with the process spectra.Results:The model with different densities showed better prediction performance and robustness than the model with fixed powder density.In addition,the blending end-points of APIs and excipients were inconsistent because of the differences in the physical properties and chemical contents among the materials of the design batches.For the complex systems of multi-components,using the PCA-MBSD method to determine the blending end-point of each component is difficult.In these conditions,a quantitative method is a more suitable alternative.Conclusions:Our results demonstrated that the effect of density plays an important role in improving the performance of the model,and a robust modeling method has been developed.展开更多
The scandium terminal imido complex supported by a monoanionic tetradentate NNNN ligand, [LSc=N(DIPP)](L = [MeC(N(DIPP))CHC(Me)(NCH2CH2N(Me)CH2CH2NMe2]-, DIPP = 2,6-(iPr)2C6H3)(1), undergoes a C–N bond cleavage at el...The scandium terminal imido complex supported by a monoanionic tetradentate NNNN ligand, [LSc=N(DIPP)](L = [MeC(N(DIPP))CHC(Me)(NCH2CH2N(Me)CH2CH2NMe2]-, DIPP = 2,6-(iPr)2C6H3)(1), undergoes a C–N bond cleavage at elevated temperature to give a mononuclear scandium anilido intermediate 2a, which subsequently aggregates into a binuclear scandium anilido complex 2. The mononuclear intermediate 2a reacts with alkyne or imine to provide two scandium anilido complexes 3 and 4, which contain a dianionic tetradentate NNNC ligand or a dianionic tetradentate NNNN ligand. DFT calculations on the reaction mechanism of C–N bond cleavage in 1 were also performed.展开更多
文摘Lack of up-to-date information on efficient operation and maintenance of EPDS （electric power distribution systems）, Nigeria is addressed by designing and implementing an indigenous real-time monitoring and diagnosis system. The system encompasses the development of software driven hardware positioned at the remotely located sub-stations at the low voltage level to keep track of the network in real-time. The detection of faults exploits threshold passing algorithm through continuous monitoring of the network power quality. Communication between the RTU （remote terminal unit） and the DCC （distribution control center） which is based on GSM is initiated by disturbance. The DCC performs fault evaluation processing using the received data and predetermined faults signatures to determine the nature of disturbance and presents the result in graphic user interface environment. A fault reporting time of 2 s was achieved. The developed system exhibits a high degree of accuracy and manifests no spurious reports during testing. The resultant system limits the effects of interruption and increases power availability by reducing the down time. The system strengthens engineering and management capabilities required to enhance reliability by providing information about the network health status.
基金the National S&T Major Project of China(No.2018ZX09201011)。
文摘Objectives:This study is aimed to explore the blending process of Dahuang soda tablets.These are composed of two active pharmaceutical ingredients(APIs,emodin and emodin methyl ether)and four kinds of excipients(sodium bicarbonate,starch,sucrose,and magnesium stearate).Also,the objective is to develop a more robust model to determine the blending end-point.Methods:Qualitative and quantitative methods based on near-infrared(NIR)spectroscopy were established to monitor the homogeneity of the powder during the blending process.A calibration set consisting of samples from 15 batches was used to develop two types of calibration models with the partial least squares regression(PLSR)method to explore the influence of density on the model robustness.The principal component analysis-moving block standard deviation(PCA-MBSD)method was used for the end-point determination of the blending with the process spectra.Results:The model with different densities showed better prediction performance and robustness than the model with fixed powder density.In addition,the blending end-points of APIs and excipients were inconsistent because of the differences in the physical properties and chemical contents among the materials of the design batches.For the complex systems of multi-components,using the PCA-MBSD method to determine the blending end-point of each component is difficult.In these conditions,a quantitative method is a more suitable alternative.Conclusions:Our results demonstrated that the effect of density plays an important role in improving the performance of the model,and a robust modeling method has been developed.
基金This work was supported by the National Natural Science Foundation of China(21325210,21132002,21121062)the State Key Basic Research&Development Program(2012CB821600)the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The scandium terminal imido complex supported by a monoanionic tetradentate NNNN ligand, [LSc=N(DIPP)](L = [MeC(N(DIPP))CHC(Me)(NCH2CH2N(Me)CH2CH2NMe2]-, DIPP = 2,6-(iPr)2C6H3)(1), undergoes a C–N bond cleavage at elevated temperature to give a mononuclear scandium anilido intermediate 2a, which subsequently aggregates into a binuclear scandium anilido complex 2. The mononuclear intermediate 2a reacts with alkyne or imine to provide two scandium anilido complexes 3 and 4, which contain a dianionic tetradentate NNNC ligand or a dianionic tetradentate NNNN ligand. DFT calculations on the reaction mechanism of C–N bond cleavage in 1 were also performed.
