Aging diagnosis of batteries is essential to ensure that the energy storage systems operate within a safe region.This paper proposes a novel cell to pack health and lifetime prognostics method based on the combination...Aging diagnosis of batteries is essential to ensure that the energy storage systems operate within a safe region.This paper proposes a novel cell to pack health and lifetime prognostics method based on the combination of transferred deep learning and Gaussian process regression.General health indicators are extracted from the partial discharge process.The sequential degradation model of the health indicator is developed based on a deep learning framework and is migrated for the battery pack degradation prediction.The future degraded capacities of both battery pack and each battery cell are probabilistically predicted to provide a comprehensive lifetime prognostic.Besides,only a few separate battery cells in the source domain and early data of battery packs in the target domain are needed for model construction.Experimental results show that the lifetime prediction errors are less than 25 cycles for the battery pack,even with only 50 cycles for model fine-tuning,which can save about 90%time for the aging experiment.Thus,it largely reduces the time and labor for battery pack investigation.The predicted capacity trends of the battery cells connected in the battery pack accurately reflect the actual degradation of each battery cell,which can reveal the weakest cell for maintenance in advance.展开更多
Surface Ag granular packs(SAgPs) have been fabricated from dual-phase Ag_(35.5)Zn_(64.5) precursor alloy consisting of both e and c phases by using a facile one-step triangle wave potential cycling in 0.5 mol·L^(...Surface Ag granular packs(SAgPs) have been fabricated from dual-phase Ag_(35.5)Zn_(64.5) precursor alloy consisting of both e and c phases by using a facile one-step triangle wave potential cycling in 0.5 mol·L^(-1) KOH.During the continuous potential cyclic sweeping, the c phases preferentially dissolve during the anodic scan and dominant reduction reactions of Ag cations lead to redeposition and accumulation of Ag atoms together to form SAg Ps during cathodic scan. The e phases stay inactive to form a continuous skeleton in the inner regions. SAg Ps with an average particle size of 94-129 nm can be obtained at scan rates of 25, 50 and 100 mV·s^(-1) for 100 triangle wave potential cycles. SAgPs formed at a scan rate of 50 mV·s^(-1) exhibit superior oxygen reduction reaction performances with the onset potential of 0.93 V, half-wave potential of 0.72 V and an electron transfer number of 4.0.The above-mentioned SAgPs have superior stabilities as ORR catalysts.展开更多
Objective:The aim of this study was to measure the leakage by two methods with ion chamber and ready packs film,and to investigate the feasibility and the advantages of using two dosimetry methods for assessing leakag...Objective:The aim of this study was to measure the leakage by two methods with ion chamber and ready packs film,and to investigate the feasibility and the advantages of using two dosimetry methods for assessing leakage radiation around the head of the linear accelerators.Methods:Measurements were performed using a 30 cm3ion chamber;the gantry at 0°,the X-ray head at 0°,the field size at between the central axis and a plane surface at a FSD of 100 as a reference,a series of concentric circles having radii of 50,75,and 100 cm with their common centre at the reference point.The absorbed dose was measured at the reference point,and this would be used as the reference dose.With the diaphragm closed,the measurements were taken along the circumference of the three circles and at 45°intervals.Results:Leakage radiations while the treatment head was in the vertical position varied between 0.016%–0.04%.With the head lying horizontally,leakage radiation was the same order magnitude and varied between 0.02%–0.07%.In the second method,the verification was accomplished by closing the collimator jaws and covering the head of the treatment unit with the ready pack films.The films were marked to permit the determination of their positions on the machine after exposed and processed.With the diaphragm closed,and the ready packs films around the linear accelerator the beam turned on for 2500 cGy(2500 MU).The optical density of these films was measured and compared with this of the reference dose.Leakage radiation varied according to the film positions and the magnitude of leakage was between 0.005%–0.075%.Conclusion:The differences between the values of the leakage radiation levels observed at different measurement points do not only reflect differences in the effective shielding thickness of the head wall,but are also related to differences in the distances between the target and the measurement points.The experimental errors involved in dosimetric measurement also contribute to such differences.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51875054,U1864212)Graduate Research and Innovation Foundation of Chongqing+2 种基金China(Grant No.CYS20018)Chongqing Municipal Natural Science Foundation for Distinguished Young Scholars of China(Grant No.cstc2019jcyjjq X0016)Chongqing Science and Technology Bureau of China。
文摘Aging diagnosis of batteries is essential to ensure that the energy storage systems operate within a safe region.This paper proposes a novel cell to pack health and lifetime prognostics method based on the combination of transferred deep learning and Gaussian process regression.General health indicators are extracted from the partial discharge process.The sequential degradation model of the health indicator is developed based on a deep learning framework and is migrated for the battery pack degradation prediction.The future degraded capacities of both battery pack and each battery cell are probabilistically predicted to provide a comprehensive lifetime prognostic.Besides,only a few separate battery cells in the source domain and early data of battery packs in the target domain are needed for model construction.Experimental results show that the lifetime prediction errors are less than 25 cycles for the battery pack,even with only 50 cycles for model fine-tuning,which can save about 90%time for the aging experiment.Thus,it largely reduces the time and labor for battery pack investigation.The predicted capacity trends of the battery cells connected in the battery pack accurately reflect the actual degradation of each battery cell,which can reveal the weakest cell for maintenance in advance.
基金financially supported by the State Key Laboratory of Advanced Metals and Materials (No.2018-ZD04)the State Key Laboratory of Metal Material for Marine Equipment and Application (No. SKLMEA-K201806)+2 种基金the Natural Science Foundation of China (Nos. 51671106 and 51931008)the Natural Science Foundation of Jiangsu Province (Nos. BK20171424and BE2019119)the National Defense Basic Scientific Research Program of China (No. JCKY08414C020)。
文摘Surface Ag granular packs(SAgPs) have been fabricated from dual-phase Ag_(35.5)Zn_(64.5) precursor alloy consisting of both e and c phases by using a facile one-step triangle wave potential cycling in 0.5 mol·L^(-1) KOH.During the continuous potential cyclic sweeping, the c phases preferentially dissolve during the anodic scan and dominant reduction reactions of Ag cations lead to redeposition and accumulation of Ag atoms together to form SAg Ps during cathodic scan. The e phases stay inactive to form a continuous skeleton in the inner regions. SAg Ps with an average particle size of 94-129 nm can be obtained at scan rates of 25, 50 and 100 mV·s^(-1) for 100 triangle wave potential cycles. SAgPs formed at a scan rate of 50 mV·s^(-1) exhibit superior oxygen reduction reaction performances with the onset potential of 0.93 V, half-wave potential of 0.72 V and an electron transfer number of 4.0.The above-mentioned SAgPs have superior stabilities as ORR catalysts.
文摘Objective:The aim of this study was to measure the leakage by two methods with ion chamber and ready packs film,and to investigate the feasibility and the advantages of using two dosimetry methods for assessing leakage radiation around the head of the linear accelerators.Methods:Measurements were performed using a 30 cm3ion chamber;the gantry at 0°,the X-ray head at 0°,the field size at between the central axis and a plane surface at a FSD of 100 as a reference,a series of concentric circles having radii of 50,75,and 100 cm with their common centre at the reference point.The absorbed dose was measured at the reference point,and this would be used as the reference dose.With the diaphragm closed,the measurements were taken along the circumference of the three circles and at 45°intervals.Results:Leakage radiations while the treatment head was in the vertical position varied between 0.016%–0.04%.With the head lying horizontally,leakage radiation was the same order magnitude and varied between 0.02%–0.07%.In the second method,the verification was accomplished by closing the collimator jaws and covering the head of the treatment unit with the ready pack films.The films were marked to permit the determination of their positions on the machine after exposed and processed.With the diaphragm closed,and the ready packs films around the linear accelerator the beam turned on for 2500 cGy(2500 MU).The optical density of these films was measured and compared with this of the reference dose.Leakage radiation varied according to the film positions and the magnitude of leakage was between 0.005%–0.075%.Conclusion:The differences between the values of the leakage radiation levels observed at different measurement points do not only reflect differences in the effective shielding thickness of the head wall,but are also related to differences in the distances between the target and the measurement points.The experimental errors involved in dosimetric measurement also contribute to such differences.
