The practical application of energy-dense lithium(Li)metal batteries is severely hindered by the lack of suitable electrolytes.Weakening solvent coordination to enhance Li+kinetics has become a critical principle in e...The practical application of energy-dense lithium(Li)metal batteries is severely hindered by the lack of suitable electrolytes.Weakening solvent coordination to enhance Li+kinetics has become a critical principle in electrolyte design.Here,we propose an electrolyte design strategy that weakens Li^(+)-solvent coordination through the synergistic drag effects of dual diluents.Specifically,the-CF_(2)H group in ethyl 1,1,2,2-tetrafluoroethyl ether(ETE)forms hydrogen bonds with the oxygen atom in 1,2-dimethoxyethane(DME),while the electron-donating-N=and C_(2)H_(5)O-groups in ethoxy(pentafluoro)cyclotriphosphazene(PFPN)coordinate synergistically with Li^(+).The combined effects of hydrogen bonding between ETE and DME,along with the coordination of PFPN with Li^(+),weaken the Li^(+)-DME interaction and promote anion-enriched solvation structure,thereby facilitating Li^(+)desolvation process and forming an inorganic-rich solid-electrolyte interphase.In a Li metal battery with a 30μm ultrathin Li anode and high-loading LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)cathode(23.5 mg cm^(-2)),80% of capacity was achieved after 430 cycles at 4.3 V and 84% after 310 cycles at 4.5 V.Furthermore,a 331 mAh pouch cell achieved 148 cycles with 94.9% of capacity retention.展开更多
To address the issue of deteriorated PCB image quality in the quality inspection process due to insufficient or uneven lighting, we proposed an image enhancement fusion algorithm based on different color spaces. First...To address the issue of deteriorated PCB image quality in the quality inspection process due to insufficient or uneven lighting, we proposed an image enhancement fusion algorithm based on different color spaces. Firstly, an improved MSRCR method was employed for brightness enhancement of the original image. Next, the color space of the original image was transformed from RGB to HSV, followed by processing the S-channel image using bilateral filtering and contrast stretching algorithms. The V-channel image was subjected to brightness enhancement using adaptive Gamma and CLAHE algorithms. Subsequently, the processed image was transformed back to the RGB color space from HSV. Finally, the images processed by the two algorithms were fused to create a new RGB image, and color restoration was performed on the fused image. Comparative experiments with other methods indicated that the contrast of the image was optimized, texture features were more abundantly preserved, brightness levels were significantly improved, and color distortion was prevented effectively, thus enhancing the quality of low-lit PCB images.展开更多
Fine particulate matter(PM2.5)is a major contributor to infant mortality.However,the attributable global burden remains unclear due to the absence of a nonlinear exposure-response function that links all-cause infant ...Fine particulate matter(PM2.5)is a major contributor to infant mortality.However,the attributable global burden remains unclear due to the absence of a nonlinear exposure-response function that links all-cause infant mortality to various PM2.5 concentrations.In this study,we systematically reviewed the literature on PM2.5 exposure and under-five child mortality,then conducted multicenter epidemiological analyses using Demographic and Health Survey(DHS)data with fixed-effects logit regression.We integrated literature-derived estimates with local PM2.5-mortality associations across multiple regions.Using meta-regression,we quantified per unit exposure effects to develop a nonlinear exposure-response function,subsequently extrapolated to 189 countries(1998–2019)to estimate the global infant mortality burden attributable to PM2.5 exposure.The results showed that prenatal exposure was more strongly associated with increased infant mortality in both linear and nonlinear analyses.The local effect of prenatal exposure was higher at the low-concentration end(<20μg/m^(3))than at the high-concentration end(>20μg/m^(3)).The attributable deaths declined from 2.22 to 1.44 million,yet the attributable fraction rose from 32.6%to 39.3%,indicating persistent PM2.5 risks despite child health improvements.These findings suggest that,although the improved child health partially mitigated the adverse effects of worsening air quality between 1998 and 2019,prenatal PM2.5 exposure remained a significant risk factor.展开更多
From sport to business,success follows China’s Prince of Gymnastics People around the world gasped in awe when the final torchbearer at the opening ceremony of the Beijing Olympics lifted into the air
The Lagrangian integral time scale(LITS)is a crucial characteristic for investigating the changes in fluid dynamics induced by the chaotic nature,and the finitetime Lyapunov exponent(FTLE)serves as a key measure in th...The Lagrangian integral time scale(LITS)is a crucial characteristic for investigating the changes in fluid dynamics induced by the chaotic nature,and the finitetime Lyapunov exponent(FTLE)serves as a key measure in the analysis of chaos.In this study,a new LITS model with an explicit theoretical basis and broad applicability is proposed based on the FTLE,along with a verification and evaluation criterion grounded in the Lagrangian velocity correlation coefficient.The model is used to cavitating the flow around a Clark-Y hydrofoil,and the LITS is investigated.It leads to the determination of model constants applicable to cavitating flow.The model is evaluated by the Lagrangian velocity correlation coefficient in comparison with other solution methods.All the results show that the LITS model can offer a new perspective and a new approach for studying the changes in fluid dynamics from a Lagrangian viewpoint.展开更多
基金supported by the Fund of University of South China(201RGC013 and 200XQD052)the Youth Science Fund Project of Hunan Provincial Natural Science Foundation(2224SZ048)。
文摘The practical application of energy-dense lithium(Li)metal batteries is severely hindered by the lack of suitable electrolytes.Weakening solvent coordination to enhance Li+kinetics has become a critical principle in electrolyte design.Here,we propose an electrolyte design strategy that weakens Li^(+)-solvent coordination through the synergistic drag effects of dual diluents.Specifically,the-CF_(2)H group in ethyl 1,1,2,2-tetrafluoroethyl ether(ETE)forms hydrogen bonds with the oxygen atom in 1,2-dimethoxyethane(DME),while the electron-donating-N=and C_(2)H_(5)O-groups in ethoxy(pentafluoro)cyclotriphosphazene(PFPN)coordinate synergistically with Li^(+).The combined effects of hydrogen bonding between ETE and DME,along with the coordination of PFPN with Li^(+),weaken the Li^(+)-DME interaction and promote anion-enriched solvation structure,thereby facilitating Li^(+)desolvation process and forming an inorganic-rich solid-electrolyte interphase.In a Li metal battery with a 30μm ultrathin Li anode and high-loading LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)cathode(23.5 mg cm^(-2)),80% of capacity was achieved after 430 cycles at 4.3 V and 84% after 310 cycles at 4.5 V.Furthermore,a 331 mAh pouch cell achieved 148 cycles with 94.9% of capacity retention.
文摘To address the issue of deteriorated PCB image quality in the quality inspection process due to insufficient or uneven lighting, we proposed an image enhancement fusion algorithm based on different color spaces. Firstly, an improved MSRCR method was employed for brightness enhancement of the original image. Next, the color space of the original image was transformed from RGB to HSV, followed by processing the S-channel image using bilateral filtering and contrast stretching algorithms. The V-channel image was subjected to brightness enhancement using adaptive Gamma and CLAHE algorithms. Subsequently, the processed image was transformed back to the RGB color space from HSV. Finally, the images processed by the two algorithms were fused to create a new RGB image, and color restoration was performed on the fused image. Comparative experiments with other methods indicated that the contrast of the image was optimized, texture features were more abundantly preserved, brightness levels were significantly improved, and color distortion was prevented effectively, thus enhancing the quality of low-lit PCB images.
基金supported by the National Key R&D Program of China(2023YFC3708304,2022YFC3703000)National Natural Science Foundation of China(42422507,42375179)+1 种基金Beijing Natural Science Foundation(JQ24052)Shanghai Tongji Gao Tingyao Environmental Science&Technology Development Foundation,China.
文摘Fine particulate matter(PM2.5)is a major contributor to infant mortality.However,the attributable global burden remains unclear due to the absence of a nonlinear exposure-response function that links all-cause infant mortality to various PM2.5 concentrations.In this study,we systematically reviewed the literature on PM2.5 exposure and under-five child mortality,then conducted multicenter epidemiological analyses using Demographic and Health Survey(DHS)data with fixed-effects logit regression.We integrated literature-derived estimates with local PM2.5-mortality associations across multiple regions.Using meta-regression,we quantified per unit exposure effects to develop a nonlinear exposure-response function,subsequently extrapolated to 189 countries(1998–2019)to estimate the global infant mortality burden attributable to PM2.5 exposure.The results showed that prenatal exposure was more strongly associated with increased infant mortality in both linear and nonlinear analyses.The local effect of prenatal exposure was higher at the low-concentration end(<20μg/m^(3))than at the high-concentration end(>20μg/m^(3)).The attributable deaths declined from 2.22 to 1.44 million,yet the attributable fraction rose from 32.6%to 39.3%,indicating persistent PM2.5 risks despite child health improvements.These findings suggest that,although the improved child health partially mitigated the adverse effects of worsening air quality between 1998 and 2019,prenatal PM2.5 exposure remained a significant risk factor.
文摘From sport to business,success follows China’s Prince of Gymnastics People around the world gasped in awe when the final torchbearer at the opening ceremony of the Beijing Olympics lifted into the air
基金Project supported by the Key Project of the National Natural Science Foundation of China(No.52336001)the Natural Science Foundation of Zhejiang Province of China(No.LR20E090001)。
文摘The Lagrangian integral time scale(LITS)is a crucial characteristic for investigating the changes in fluid dynamics induced by the chaotic nature,and the finitetime Lyapunov exponent(FTLE)serves as a key measure in the analysis of chaos.In this study,a new LITS model with an explicit theoretical basis and broad applicability is proposed based on the FTLE,along with a verification and evaluation criterion grounded in the Lagrangian velocity correlation coefficient.The model is used to cavitating the flow around a Clark-Y hydrofoil,and the LITS is investigated.It leads to the determination of model constants applicable to cavitating flow.The model is evaluated by the Lagrangian velocity correlation coefficient in comparison with other solution methods.All the results show that the LITS model can offer a new perspective and a new approach for studying the changes in fluid dynamics from a Lagrangian viewpoint.
