Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance pr...Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.展开更多
[Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the fi...[Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the first time after the disaster, and then built an assessment model to estimate the potential economic losses. [Result] The total loss reached 16.57×10^2 million Yuan, in which indirect economic loss was up to 2.42×10^2 million yaun while the actual direct economic loss was around 14.15×10^2 million Yuan. [Conclusion] The proportional coefficient method is a rapid and efficient method for evaluating the indirect loss caused by disasters.展开更多
A unified power flow controller(UPFC)combines the advantages of various flexible alternating current transmission system(FACTS)devices into a powerful format.Using a 500 kV power grid,this study evaluates the selectio...A unified power flow controller(UPFC)combines the advantages of various flexible alternating current transmission system(FACTS)devices into a powerful format.Using a 500 kV power grid,this study evaluates the selection and use of a UPFC to improve transmission capacity.The"UPFC unit capacity control proportionality coefficient"is introduced to quantify the control effect of the UPFC,and an optimal calculation method for the UPFC capacity is presented.Following the proposal of a UPFC site selection process,the data of an existing power grid is used to conduct simulations.The simulation results show that the UPFC has a strong ability to improve transmission capacity,and its use is greatly advantageous.Additionally,by applying the proposed selection method,the control effect and economic benefits of the UPFC can be comprehensively considered during project site selection.These findings have a guiding significance for UPFC site selection in ultra-high voltage power grids.展开更多
Cubature Kalman Filter(CKF)offers a promising solution to handle the data fusion of integrated nonlinear INS/GNSS(Inertial Navigation System/Global Navigation Satellite System)navigation.However,its accuracy is degrad...Cubature Kalman Filter(CKF)offers a promising solution to handle the data fusion of integrated nonlinear INS/GNSS(Inertial Navigation System/Global Navigation Satellite System)navigation.However,its accuracy is degraded by inaccurate kinematic noise statistics which originate from disturbances of system dynamics.This paper develops a method of closed-loop feedback covariance control to address the above problem of CKF.In this method,the posterior state and its covariance are fed back to the filtering process to constitute a closed-loop structure for CKF covariance propagation.Subsequently,based on the maximum likelihood principle,a control scheme of the prior state covariance is established by using the feedback state and covariance within an estimation window and further adopting a proportional coefficient to amplify the feedback terms in recent time steps for the full use of new information to reflect actual system characteristics.Since it does not directly use kinematic noise covariance,the proposed method can effectively avoid the adverse impact of inaccurate kinematic noise statistics on filtering solutions.Further,it can also guarantee the prior state covariance to be positive semi-definite without involving extra measures.The efficacy of the proposed method is validated by simulations and experiments for integrated INS/GNSS navigation.展开更多
文摘Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.
基金Supported by National Key Technology Research and Development Program(2008BAK50B06)~~
文摘[Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the first time after the disaster, and then built an assessment model to estimate the potential economic losses. [Result] The total loss reached 16.57×10^2 million Yuan, in which indirect economic loss was up to 2.42×10^2 million yaun while the actual direct economic loss was around 14.15×10^2 million Yuan. [Conclusion] The proportional coefficient method is a rapid and efficient method for evaluating the indirect loss caused by disasters.
基金supported by State Grid Corporation’s Science and Technology Project“Research and Demonstration of Technical Measures for Improving Voltage Supporting Capacity of Large-scale Urban Power Grid”(52094016000Y)
文摘A unified power flow controller(UPFC)combines the advantages of various flexible alternating current transmission system(FACTS)devices into a powerful format.Using a 500 kV power grid,this study evaluates the selection and use of a UPFC to improve transmission capacity.The"UPFC unit capacity control proportionality coefficient"is introduced to quantify the control effect of the UPFC,and an optimal calculation method for the UPFC capacity is presented.Following the proposal of a UPFC site selection process,the data of an existing power grid is used to conduct simulations.The simulation results show that the UPFC has a strong ability to improve transmission capacity,and its use is greatly advantageous.Additionally,by applying the proposed selection method,the control effect and economic benefits of the UPFC can be comprehensively considered during project site selection.These findings have a guiding significance for UPFC site selection in ultra-high voltage power grids.
基金co-supported by the Guangdong Basic and Applied Basic Research Foundation,China (No.2023A1515011560)the Key Research and Development Program of Shaanxi,China (No. 2023-YBGY-375)+2 种基金the Aeronautical Science Foundation of China (No. 20200019053003)the Shenzhen Science and Technology Program,China (Nos.JCYJ20220530161606015 and JCYJ20210324121602008)the National Natural Science Foundation of China (Nos.41904028 and 42004021)
文摘Cubature Kalman Filter(CKF)offers a promising solution to handle the data fusion of integrated nonlinear INS/GNSS(Inertial Navigation System/Global Navigation Satellite System)navigation.However,its accuracy is degraded by inaccurate kinematic noise statistics which originate from disturbances of system dynamics.This paper develops a method of closed-loop feedback covariance control to address the above problem of CKF.In this method,the posterior state and its covariance are fed back to the filtering process to constitute a closed-loop structure for CKF covariance propagation.Subsequently,based on the maximum likelihood principle,a control scheme of the prior state covariance is established by using the feedback state and covariance within an estimation window and further adopting a proportional coefficient to amplify the feedback terms in recent time steps for the full use of new information to reflect actual system characteristics.Since it does not directly use kinematic noise covariance,the proposed method can effectively avoid the adverse impact of inaccurate kinematic noise statistics on filtering solutions.Further,it can also guarantee the prior state covariance to be positive semi-definite without involving extra measures.The efficacy of the proposed method is validated by simulations and experiments for integrated INS/GNSS navigation.