Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems,hydrogen energy is gaining more attention all over the world.Solid oxide fuel cell(SOFC)is a promising power gener...Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems,hydrogen energy is gaining more attention all over the world.Solid oxide fuel cell(SOFC)is a promising power generation technology operating on hydrogen with a high efficiency.To further boost the power output of a single cell and thus a single stack,increasing the cell area is an effective route.However,it was recently found that further increasing the effective area of an SOFC single cell with a flat-tubular structure and symmetric double-sided cathodes would result in a lower areal performance.In this work,a multi-physical model is built to study the effect of the effective area on the cell performance.The distribution of different physical fields is systematically analyzed.Optimization of the cell performance is also pursued by systematically tuning the cell operating condition and the current collection setup.An improvement of 42%is revealed by modifying the inlet gas flow rates and by enhancing the current collection.In the future,optimization of cell geometry will be performed to improve the homogeneity of different physical fields and thus to improve the stability of the cell.展开更多
The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened devices.However,owing to the minimum physical gate length of only 35 nm,the physical area o...The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened devices.However,owing to the minimum physical gate length of only 35 nm,the physical area of a standard 6T SRAM unit is approximately 0.16μm^(2),resulting in a significant enhancement of multi-cell charge-sharing effects.Multiple-cell upsets(MCUs)have become the primary physical mechanism behind single-event upsets(SEUs)in advanced nanometer node devices.The range of ionization track effects increases with higher ion energies,and spacecraft in orbit primarily experience SEUs caused by high-energy ions.However,ground accelerator experiments have mainly obtained low-energy ion irradiation data.Therefore,the impact of ion energy on the SEU cross section,charge collection mechanisms,and MCU patterns and quantities in advanced nanometer devices remains unclear.In this study,based on the experimental platform of the Heavy Ion Research Facility in Lanzhou,low-and high-energy heavy-ion beams were used to study the SEUs of 28 nm SRAM devices.The influence of ion energy on the charge collection processes of small-sensitive-volume devices,MCU patterns,and upset cross sections was obtained,and the applicable range of the inverse cosine law was clarified.The findings of this study are an important guide for the accurate evaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.展开更多
We study the problem of multiple node upset （MNU） using three-dimensional device simulation. The results show the transient floating node and charge lateral diffusion are the key reasons for MNU. We compare the MNU ...We study the problem of multiple node upset （MNU） using three-dimensional device simulation. The results show the transient floating node and charge lateral diffusion are the key reasons for MNU. We compare the MNU with multiple bit upset （MBU）,and find that their characteristics are different. Methods to avoid MNU are also discussed.展开更多
Background Autologous hematopoietic stem cell(HSC)transplantation remains the recommended treatment for eligible patients with multiple myeloma(MM).Increasing the number of transplanted CD34^(+)cells shorten the time ...Background Autologous hematopoietic stem cell(HSC)transplantation remains the recommended treatment for eligible patients with multiple myeloma(MM).Increasing the number of transplanted CD34^(+)cells shorten the time to hematopoietic reconstitution and increases the overall survival of patients.With the harvest of a sufficient CD34^(+)cell number being crucial,this study aimed to predict the factors that affect stem cell collection.Methods We conducted a retrospective study of 110 patients who were newly diagnosed with MM and underwent autologous HSC collection at Beijing Jishuitan Hospital between March 2016 and July 2022.Multiple factors were analyzed using the Mann-Whitney U tests for between-group comparisons.Differences were considered statistically significant at P<0.05.Results We found that patient age affected stem cell collection significantly;for patients younger than 55 years,the number of CD34^(+)cells harvested may be≥2×10^(6)/L,is unlikely to reach 5×10^(6)/L.Platelet count at initial mobilization was a predictor of the number of CD34^(+)cells collected.Collection may fail when the platelet count at initial mobilization is below 17×10^(9)/L and may be excellent when it is higher than 199×10^(9)/L.Conclusions This finding could guide us to predict the approximate number of CD34^(+)cells collected in advance during autologous transplant mobilization for MM and to decide in advance whether to apply plerixafor to improve the number of HSCs collected.展开更多
BACKGROUND Early prediction of response to percutaneous catheter drainage(PCD)of necrotic collections in acute pancreatitis(AP)using simple and objective tests is critical as it may determine patient prognosis.The rol...BACKGROUND Early prediction of response to percutaneous catheter drainage(PCD)of necrotic collections in acute pancreatitis(AP)using simple and objective tests is critical as it may determine patient prognosis.The role of white blood cell(WBC)count and neutrophil-lymphocyte ratio(NLR)has not been assessed as a tool of early prediction of PCD success and is the focus of this study.AIM To assess the value of WBC and NLR in predicting response to PCD in AP.METHODS This retrospective study comprised consecutive patients with AP who underwent PCD between June 2018 and December 2019.Severity and fluid collections were classified according to the revised Atlanta classification and organ failure was defined according to the modified Marshall Score.WBC and NLR were monitored 24 h prior PCD(WBC-0/NLR-0)and 24 h(WBC-1/NLR-1),48 h(WBC-2/NLR-2)and 72 h(WBC-3/NLR-3)after PCD.NLR was calculated by dividing the number of neutrophils by the number of lymphocytes.The association of success of PCD(defined as survival without the need for surgery)with WBC and NLR was assessed.The trend of WBC and NLR was also assessed post PCD.RESULTS One hundred fifty-five patients[median age 40±13.6(SD),64.5%males,53.5%severe AP]were included in the final analysis.PCD was done for acute necrotic collection in 99(63.8%)patients and walled-off necrosis in 56(36.1%)patients.Median pain to PCD interval was 24±69.89 d.PCD was successful in 109 patients(group 1)and 46 patients(group 2)who failed to respond.There was no significant difference in the baseline characteristics between the two groups except the severity of AP and frequency of organ failure.Both WBC and NLR showed an overall decreasing trend.There was a significant difference between WBC-0 and WBC-1(P=0.0001).WBC-1 and NLR-1 were significantly different between the two groups(P=0.048 and 0.003,respectively).The area under the curve of WBC-1 and NLR-1 for predicting the success of PCD was 0.602 and 0.682,respectively.At a cut-off value of 9.87 for NLR-1,the sensitivity and specificity for pr展开更多
Current density-voltage(J-V) hysteresis issue caused by unbalanced charge transport has greatly limited the improvement of power conversion efficiency(PCE) of halide perovskite solar cells(PSCs). Herein, hollow TiO2 m...Current density-voltage(J-V) hysteresis issue caused by unbalanced charge transport has greatly limited the improvement of power conversion efficiency(PCE) of halide perovskite solar cells(PSCs). Herein, hollow TiO2 mesoporous electron transport layer(ETL) was used to fabricate PSCs. The structure-dependent charge collection as well as its effect on PCE and hysteresis impactor(HI) of PSC were investigated. The results demonstrate that TiO2 hollow spheres in a size of around 50 nm (HS-50) can form a high quality perovskite/ETL interface with a less trap density. Moreover, the hollow TiO2 with the thin shell can help promote the extraction of electrons from perovskite layer to ETL, so as to reduce the charge accumulation and recombination at the perovskite/ETL interface and alleviate the hysteresis behavior. As a result, PSCs with HS-50 TiO2 delivered a champion PCE of 16.81% with a small HI of 0.0297, indicating a better performance than the commercial P25(PCE of 15.87%, HI of 0.2571).展开更多
基金the National Natural Science Foundation of China(Grant Nos.11802106,11932005,U20A20251,and 52102226)the Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.GJHZ20220913143009017)the Development and Reform Commission of Shenzhen Municipality,China(Grant No.XMHT20220103004).
文摘Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems,hydrogen energy is gaining more attention all over the world.Solid oxide fuel cell(SOFC)is a promising power generation technology operating on hydrogen with a high efficiency.To further boost the power output of a single cell and thus a single stack,increasing the cell area is an effective route.However,it was recently found that further increasing the effective area of an SOFC single cell with a flat-tubular structure and symmetric double-sided cathodes would result in a lower areal performance.In this work,a multi-physical model is built to study the effect of the effective area on the cell performance.The distribution of different physical fields is systematically analyzed.Optimization of the cell performance is also pursued by systematically tuning the cell operating condition and the current collection setup.An improvement of 42%is revealed by modifying the inlet gas flow rates and by enhancing the current collection.In the future,optimization of cell geometry will be performed to improve the homogeneity of different physical fields and thus to improve the stability of the cell.
基金supported by the National Natural Science Foundation of China(Nos.12105341 and 12035019)the opening fund of Key Laboratory of Silicon Device and Technology,Chinese Academy of Sciences(No.KLSDTJJ2022-3).
文摘The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened devices.However,owing to the minimum physical gate length of only 35 nm,the physical area of a standard 6T SRAM unit is approximately 0.16μm^(2),resulting in a significant enhancement of multi-cell charge-sharing effects.Multiple-cell upsets(MCUs)have become the primary physical mechanism behind single-event upsets(SEUs)in advanced nanometer node devices.The range of ionization track effects increases with higher ion energies,and spacecraft in orbit primarily experience SEUs caused by high-energy ions.However,ground accelerator experiments have mainly obtained low-energy ion irradiation data.Therefore,the impact of ion energy on the SEU cross section,charge collection mechanisms,and MCU patterns and quantities in advanced nanometer devices remains unclear.In this study,based on the experimental platform of the Heavy Ion Research Facility in Lanzhou,low-and high-energy heavy-ion beams were used to study the SEUs of 28 nm SRAM devices.The influence of ion energy on the charge collection processes of small-sensitive-volume devices,MCU patterns,and upset cross sections was obtained,and the applicable range of the inverse cosine law was clarified.The findings of this study are an important guide for the accurate evaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.
文摘We study the problem of multiple node upset （MNU） using three-dimensional device simulation. The results show the transient floating node and charge lateral diffusion are the key reasons for MNU. We compare the MNU with multiple bit upset （MBU）,and find that their characteristics are different. Methods to avoid MNU are also discussed.
文摘Background Autologous hematopoietic stem cell(HSC)transplantation remains the recommended treatment for eligible patients with multiple myeloma(MM).Increasing the number of transplanted CD34^(+)cells shorten the time to hematopoietic reconstitution and increases the overall survival of patients.With the harvest of a sufficient CD34^(+)cell number being crucial,this study aimed to predict the factors that affect stem cell collection.Methods We conducted a retrospective study of 110 patients who were newly diagnosed with MM and underwent autologous HSC collection at Beijing Jishuitan Hospital between March 2016 and July 2022.Multiple factors were analyzed using the Mann-Whitney U tests for between-group comparisons.Differences were considered statistically significant at P<0.05.Results We found that patient age affected stem cell collection significantly;for patients younger than 55 years,the number of CD34^(+)cells harvested may be≥2×10^(6)/L,is unlikely to reach 5×10^(6)/L.Platelet count at initial mobilization was a predictor of the number of CD34^(+)cells collected.Collection may fail when the platelet count at initial mobilization is below 17×10^(9)/L and may be excellent when it is higher than 199×10^(9)/L.Conclusions This finding could guide us to predict the approximate number of CD34^(+)cells collected in advance during autologous transplant mobilization for MM and to decide in advance whether to apply plerixafor to improve the number of HSCs collected.
文摘BACKGROUND Early prediction of response to percutaneous catheter drainage(PCD)of necrotic collections in acute pancreatitis(AP)using simple and objective tests is critical as it may determine patient prognosis.The role of white blood cell(WBC)count and neutrophil-lymphocyte ratio(NLR)has not been assessed as a tool of early prediction of PCD success and is the focus of this study.AIM To assess the value of WBC and NLR in predicting response to PCD in AP.METHODS This retrospective study comprised consecutive patients with AP who underwent PCD between June 2018 and December 2019.Severity and fluid collections were classified according to the revised Atlanta classification and organ failure was defined according to the modified Marshall Score.WBC and NLR were monitored 24 h prior PCD(WBC-0/NLR-0)and 24 h(WBC-1/NLR-1),48 h(WBC-2/NLR-2)and 72 h(WBC-3/NLR-3)after PCD.NLR was calculated by dividing the number of neutrophils by the number of lymphocytes.The association of success of PCD(defined as survival without the need for surgery)with WBC and NLR was assessed.The trend of WBC and NLR was also assessed post PCD.RESULTS One hundred fifty-five patients[median age 40±13.6(SD),64.5%males,53.5%severe AP]were included in the final analysis.PCD was done for acute necrotic collection in 99(63.8%)patients and walled-off necrosis in 56(36.1%)patients.Median pain to PCD interval was 24±69.89 d.PCD was successful in 109 patients(group 1)and 46 patients(group 2)who failed to respond.There was no significant difference in the baseline characteristics between the two groups except the severity of AP and frequency of organ failure.Both WBC and NLR showed an overall decreasing trend.There was a significant difference between WBC-0 and WBC-1(P=0.0001).WBC-1 and NLR-1 were significantly different between the two groups(P=0.048 and 0.003,respectively).The area under the curve of WBC-1 and NLR-1 for predicting the success of PCD was 0.602 and 0.682,respectively.At a cut-off value of 9.87 for NLR-1,the sensitivity and specificity for pr
基金This work was supported by the National Natural Science Foundation of China (Nos.21931012,52022097)the Beijing Natural Science Foundation,China (No.2202055)the Foundation of the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020048).
文摘Current density-voltage(J-V) hysteresis issue caused by unbalanced charge transport has greatly limited the improvement of power conversion efficiency(PCE) of halide perovskite solar cells(PSCs). Herein, hollow TiO2 mesoporous electron transport layer(ETL) was used to fabricate PSCs. The structure-dependent charge collection as well as its effect on PCE and hysteresis impactor(HI) of PSC were investigated. The results demonstrate that TiO2 hollow spheres in a size of around 50 nm (HS-50) can form a high quality perovskite/ETL interface with a less trap density. Moreover, the hollow TiO2 with the thin shell can help promote the extraction of electrons from perovskite layer to ETL, so as to reduce the charge accumulation and recombination at the perovskite/ETL interface and alleviate the hysteresis behavior. As a result, PSCs with HS-50 TiO2 delivered a champion PCE of 16.81% with a small HI of 0.0297, indicating a better performance than the commercial P25(PCE of 15.87%, HI of 0.2571).
