A novel control strategy for three-phase shunt active power filter (SAPF) was proposed to improve its performance under non-ideal mains voltages. The approach was inspired by our finding that the classic instantaneous...A novel control strategy for three-phase shunt active power filter (SAPF) was proposed to improve its performance under non-ideal mains voltages. The approach was inspired by our finding that the classic instantaneous reactive power theory based algorithm was unsatisfactory in terms of isolating positive sequence fundamental active components exactly under non-ideal mains voltages. So, a modified ip-iq reference current calculation method was presented. With usage of the new method, not only the positive sequence but also the fundamental active current components can be accurately isolated from load current. A deadbeat closed-loop control model is built in order to eliminate both delay error and tracking error between reference voltages and compensation voltages under unbalanced and distorted mains voltages. Computer simulation results show that the proposed strategy is effective with better tracking ability and lower total harmonic distortion (THD). The strategy is also applied to a 10 kV substation with a local electrolysis manganese plant injecting a large amount of harmonics into the power system, and is proved to be more practical and efficient.展开更多
Using Global Positioning System(GPS) data to analyze the earthquake preparation characteristics of the Kunlun Ms8.1 and the Wenchuan Ms8.0 earthquakes, we review the main research developments of earthquake forecastin...Using Global Positioning System(GPS) data to analyze the earthquake preparation characteristics of the Kunlun Ms8.1 and the Wenchuan Ms8.0 earthquakes, we review the main research developments of earthquake forecasting and the mechanisms of earthquake preparation using crustal deformation data from recent periods, and discuss the similarities and differences in the scientific approaches adopted by the Chinese and foreign scholars. We then analyze the deformation characteristics of earthquake preparation, with respect to slip and dip-slip faults. Our results show that, in order to understand the relationship between crustal deformation and earthquake preparation, research focus should be expanded from fault-scale to larger scale regions. Furthermore, the dynamic deformation characteristics associated with earthquake preparation must be considered as a multiscale, spatial-temporal process, in order to obtain the necessary criteria for strong earthquake forecasts.展开更多
A new type lead paste mixed with binders used in thin-plate, spirally wound lead acid batteries is introduced. The utility of positive active material can obtain 54.17% and 37.71% at discharge currents of 0.5C and 5.0...A new type lead paste mixed with binders used in thin-plate, spirally wound lead acid batteries is introduced. The utility of positive active material can obtain 54.17% and 37.71% at discharge currents of 0.5C and 5.0C. The investigation was performed by means of X-ray diffraction (XRD), scaning electron microscopy (SEM), infrared spectroscopy (IR), cylic voltammetry (CV), the results revealed more details on the reaction mechanism of paste-mixing. Further conclusion can be obtained that the reaction of paste-mixin is a physical process, and the chemical reactions is local reaction, which is different from traditional mixing process, the binders has some effect on the formation of battery process. The binders can dissolve in elec trolyte, which have no disadvantageous effect on the charge-discharge performance.展开更多
In an attempt to search for more potent positive inotropic agents, a series of 1-(benzylamino)-3-(4,5-dihydro[ 1,2,4]trizaolo[4,3- a]quinolin-7-yloxy)propan-2-ol derivatives was synthesized in four steps using 6-h...In an attempt to search for more potent positive inotropic agents, a series of 1-(benzylamino)-3-(4,5-dihydro[ 1,2,4]trizaolo[4,3- a]quinolin-7-yloxy)propan-2-ol derivatives was synthesized in four steps using 6-hydroxy-3,4-dihydro-2(1H)-quinolinone as a starting material, and their positive inotropic activities were evaluated by measuring the coronary blood flow (CBF) and the left ventricular pressure (LVP) followed by calculating the rate of pressure development (dp/dtmax values) in the preparation of rat Langendorff's heart. Three compounds (5d, 5g, 5j) showed favorable activities, among which 5g was shown the most potent with dp/dtmax value of 9.7% and CBF value of 17.8% at a concentration of 1×10^-5 mol/L in our in vitro study.展开更多
The aim of this investigation is to define a model of an alternating current impedance response that can identify the state of health of a porous electrode due to the blocked diffusion effect. To identify and simulate...The aim of this investigation is to define a model of an alternating current impedance response that can identify the state of health of a porous electrode due to the blocked diffusion effect. To identify and simulate different pore geometries, an analytical differential equations system was studied. Standard and low performance battery products were simulated by the model and validated with electrochemical impedance spectroscopy (EIS) experimental data. The correlation between pore structure geometries and the related battery efficiency is also addressed. This investigation may clarify the possible reasons for low performance batteries. Identifying the benchmark pore geometry, parameters may be useful for the battery producers to improve the efficiency of their products. Various recovery methods are also included in this investigation to disperse the build-up of lead sulphate crystal that limits the electrolysis process in the low performance batteries.展开更多
Production Recovery China’s apparel industry saw a sharp increase in the output for the January-September period, according to data collected from statistics-worthy
基金Project(JC200903180555A) supported by Shenzhen City Science and Technology Plan, China
文摘A novel control strategy for three-phase shunt active power filter (SAPF) was proposed to improve its performance under non-ideal mains voltages. The approach was inspired by our finding that the classic instantaneous reactive power theory based algorithm was unsatisfactory in terms of isolating positive sequence fundamental active components exactly under non-ideal mains voltages. So, a modified ip-iq reference current calculation method was presented. With usage of the new method, not only the positive sequence but also the fundamental active current components can be accurately isolated from load current. A deadbeat closed-loop control model is built in order to eliminate both delay error and tracking error between reference voltages and compensation voltages under unbalanced and distorted mains voltages. Computer simulation results show that the proposed strategy is effective with better tracking ability and lower total harmonic distortion (THD). The strategy is also applied to a 10 kV substation with a local electrolysis manganese plant injecting a large amount of harmonics into the power system, and is proved to be more practical and efficient.
基金sponsored by the National Science and Technology Support Program (2012BAK19B01)the National Natural Science Fund (41274008)
文摘Using Global Positioning System(GPS) data to analyze the earthquake preparation characteristics of the Kunlun Ms8.1 and the Wenchuan Ms8.0 earthquakes, we review the main research developments of earthquake forecasting and the mechanisms of earthquake preparation using crustal deformation data from recent periods, and discuss the similarities and differences in the scientific approaches adopted by the Chinese and foreign scholars. We then analyze the deformation characteristics of earthquake preparation, with respect to slip and dip-slip faults. Our results show that, in order to understand the relationship between crustal deformation and earthquake preparation, research focus should be expanded from fault-scale to larger scale regions. Furthermore, the dynamic deformation characteristics associated with earthquake preparation must be considered as a multiscale, spatial-temporal process, in order to obtain the necessary criteria for strong earthquake forecasts.
文摘A new type lead paste mixed with binders used in thin-plate, spirally wound lead acid batteries is introduced. The utility of positive active material can obtain 54.17% and 37.71% at discharge currents of 0.5C and 5.0C. The investigation was performed by means of X-ray diffraction (XRD), scaning electron microscopy (SEM), infrared spectroscopy (IR), cylic voltammetry (CV), the results revealed more details on the reaction mechanism of paste-mixing. Further conclusion can be obtained that the reaction of paste-mixin is a physical process, and the chemical reactions is local reaction, which is different from traditional mixing process, the binders has some effect on the formation of battery process. The binders can dissolve in elec trolyte, which have no disadvantageous effect on the charge-discharge performance.
基金supported by the National Natural Science Foundation of China(No.30560177)the Natural Science Foundation of Jilin Province of China(No.20060567).
文摘In an attempt to search for more potent positive inotropic agents, a series of 1-(benzylamino)-3-(4,5-dihydro[ 1,2,4]trizaolo[4,3- a]quinolin-7-yloxy)propan-2-ol derivatives was synthesized in four steps using 6-hydroxy-3,4-dihydro-2(1H)-quinolinone as a starting material, and their positive inotropic activities were evaluated by measuring the coronary blood flow (CBF) and the left ventricular pressure (LVP) followed by calculating the rate of pressure development (dp/dtmax values) in the preparation of rat Langendorff's heart. Three compounds (5d, 5g, 5j) showed favorable activities, among which 5g was shown the most potent with dp/dtmax value of 9.7% and CBF value of 17.8% at a concentration of 1×10^-5 mol/L in our in vitro study.
基金the financial support from the Knowledge Economy Skills Scholarships (KESS)Yuasa Battery Ltdthe University of South Wales (USW) during this research project
文摘The aim of this investigation is to define a model of an alternating current impedance response that can identify the state of health of a porous electrode due to the blocked diffusion effect. To identify and simulate different pore geometries, an analytical differential equations system was studied. Standard and low performance battery products were simulated by the model and validated with electrochemical impedance spectroscopy (EIS) experimental data. The correlation between pore structure geometries and the related battery efficiency is also addressed. This investigation may clarify the possible reasons for low performance batteries. Identifying the benchmark pore geometry, parameters may be useful for the battery producers to improve the efficiency of their products. Various recovery methods are also included in this investigation to disperse the build-up of lead sulphate crystal that limits the electrolysis process in the low performance batteries.
文摘Viscose and terylene staple fi ber market is very hot as prices rise this year.The main reason for the positive market activity is that cotton prices
文摘Production Recovery China’s apparel industry saw a sharp increase in the output for the January-September period, according to data collected from statistics-worthy