Induction melting was used as a routine method to synthesize Mg_（23）Ni_（10）, Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys, and followed by a detailed microstructural characterization which included X-ray...Induction melting was used as a routine method to synthesize Mg_（23）Ni_（10）, Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys, and followed by a detailed microstructural characterization which included X-ray diffraction（XRD）, scanning electron microscopy（SEM） with energy dispersive spectrometer（EDS）, high resolution transmission electron microscope（HRTEM） and hydrogen absorption/desorption measurements. XRD analysis results showed that Mg_2Ni and Mg phases were detected in the XRD pattern of the Mg_（23）Ni_（10） alloy, however, the La addition results in conversion from Mg to LaMg_3 and La_2Mg_（17） phases and appearance of crystal defects included dislocations, twin grain boundary and vacancy in the Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloy textures. The total maximum hydrogen absorption capacity was 4.45 wt% for the Mg_（23）Ni_（10） alloy, however, the Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys with vacancy, dislocations and twin grain boundary, absorbed 3.66 wt% and 3.60 wt%, respectively, indicating that the La addition led to decreasing of the maximum hydrogen absorption capacity. Besides, hydrogen absorption/desorption of 90% of saturated state expended for about 456 and 990 s for pristine Mg_（23）Ni_（10） alloy, by contrast, the time decreased owing to improvement of hydrogen absorption and desorption kinetics in the alloy with La element, with which the uptake time for hydrogen content to 90% of saturated state was 150 and 78 s, and 90% hydrogen can be released in 930 and 804 s for Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys in the experimental condition.展开更多
Naturally occurring radium(^(223)Ra,^(224)Ra,^(226)Ra,and^(228)Ra)isotopes have been widely applied as geochemical tracers in marine environments,especially when estimating the submarine groundwater discharge(SGD).In ...Naturally occurring radium(^(223)Ra,^(224)Ra,^(226)Ra,and^(228)Ra)isotopes have been widely applied as geochemical tracers in marine environments,especially when estimating the submarine groundwater discharge(SGD).In this sense,the influencing factors and transport mechanism of radium isotope activity in aquifers can be key information for SGD estimation.This work evaluates the adsorption/desorption behavior of^(224)Ra and^(226)Ra in the solid-liquid phase through a leaching experiment and analysis of field data.The results suggested that radium isotope activity was positively correlated with salinity and grain size,in the case of abundant sediments.Through ion analysis,we found that the ions(Na^(+),Ca^(2+),Mg^(2+),and Ba^(2+))exchanged with radium isotopes in the process of transport.A 1-D reactive transport model was established to simulate the transport process of radium isotope in aquifers.The model successfully simulated the variation of radium isotope desorption activity with salinity and was subsequently verified in the field.This study contributes to the understanding of the geochemical behavior of radium isotopes in aquifers and provides guidance for selecting a suitable groundwater endmember in SGD estimation.展开更多
The ever-increasing prevalence of microplastics and different bisphenols made the presence of bisphenol-attached microplastics a critical concern.In this study,experiments were performed to examine desorption behavior...The ever-increasing prevalence of microplastics and different bisphenols made the presence of bisphenol-attached microplastics a critical concern.In this study,experiments were performed to examine desorption behaviors and cytotoxicity performance of contaminated microplastics in aquatic surroundings and intestinal environment after ingestion by organisms(cold-/warm-blooded).The kinetic study shows that the rate of desorption for bisphenols can be enhanced threefold under simulated warm intestinal conditions.The Freundlich isotherms indicate multiple-layer desorption of the bisphenols on the heterogeneous surfaces of polyvinyl chloride(PVC)microplastics.Hysteresis was detected in the adsorption/desorption of bisphenols in a water environment,but no adsorption/desorption hysteresis was observed in the simulated intestinal conditions of warm-blooded organisms.Due to enhanced bioaccessibility,the desorption results imply that the environmental risk of contaminated PVC microplastics may be significantly increased after ingestion at a high bisphenols dosage.Although with different IC_(50),the five bisphenols released under the intestinal conditions of warm-blooded organisms can cause higher proliferation reduction in fish and human cell lines than the bisphenols released in water.This study helps elucidate the consequential fate and potential cytotoxicity of contaminated microplastics and the possible implications of the microplastics as a critical vector for bisphenols to increase the potential health risks.展开更多
基金Founded by the National Natural Science Foundation of China(51371094 and 51161015)the Hebei University Experiment Center Project(sy2015091)
文摘Induction melting was used as a routine method to synthesize Mg_（23）Ni_（10）, Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys, and followed by a detailed microstructural characterization which included X-ray diffraction（XRD）, scanning electron microscopy（SEM） with energy dispersive spectrometer（EDS）, high resolution transmission electron microscope（HRTEM） and hydrogen absorption/desorption measurements. XRD analysis results showed that Mg_2Ni and Mg phases were detected in the XRD pattern of the Mg_（23）Ni_（10） alloy, however, the La addition results in conversion from Mg to LaMg_3 and La_2Mg_（17） phases and appearance of crystal defects included dislocations, twin grain boundary and vacancy in the Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloy textures. The total maximum hydrogen absorption capacity was 4.45 wt% for the Mg_（23）Ni_（10） alloy, however, the Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys with vacancy, dislocations and twin grain boundary, absorbed 3.66 wt% and 3.60 wt%, respectively, indicating that the La addition led to decreasing of the maximum hydrogen absorption capacity. Besides, hydrogen absorption/desorption of 90% of saturated state expended for about 456 and 990 s for pristine Mg_（23）Ni_（10） alloy, by contrast, the time decreased owing to improvement of hydrogen absorption and desorption kinetics in the alloy with La element, with which the uptake time for hydrogen content to 90% of saturated state was 150 and 78 s, and 90% hydrogen can be released in 930 and 804 s for Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys in the experimental condition.
基金The Joint Funds of the National Natural Science Foundation of China under contract Nos U22A20580 and U2106203the National Natural Science Foundation of China under contract No.41706067the Open Project Program of Key Laboratory of Ecological Warning,Protection&Restoration for Bohai Sea,Ministry of Natural Resources under contract No.2022108.
文摘Naturally occurring radium(^(223)Ra,^(224)Ra,^(226)Ra,and^(228)Ra)isotopes have been widely applied as geochemical tracers in marine environments,especially when estimating the submarine groundwater discharge(SGD).In this sense,the influencing factors and transport mechanism of radium isotope activity in aquifers can be key information for SGD estimation.This work evaluates the adsorption/desorption behavior of^(224)Ra and^(226)Ra in the solid-liquid phase through a leaching experiment and analysis of field data.The results suggested that radium isotope activity was positively correlated with salinity and grain size,in the case of abundant sediments.Through ion analysis,we found that the ions(Na^(+),Ca^(2+),Mg^(2+),and Ba^(2+))exchanged with radium isotopes in the process of transport.A 1-D reactive transport model was established to simulate the transport process of radium isotope in aquifers.The model successfully simulated the variation of radium isotope desorption activity with salinity and was subsequently verified in the field.This study contributes to the understanding of the geochemical behavior of radium isotopes in aquifers and provides guidance for selecting a suitable groundwater endmember in SGD estimation.
基金supported financially by the National Natural Science Foundation of China(NSFC)(41977329)the State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control.
文摘The ever-increasing prevalence of microplastics and different bisphenols made the presence of bisphenol-attached microplastics a critical concern.In this study,experiments were performed to examine desorption behaviors and cytotoxicity performance of contaminated microplastics in aquatic surroundings and intestinal environment after ingestion by organisms(cold-/warm-blooded).The kinetic study shows that the rate of desorption for bisphenols can be enhanced threefold under simulated warm intestinal conditions.The Freundlich isotherms indicate multiple-layer desorption of the bisphenols on the heterogeneous surfaces of polyvinyl chloride(PVC)microplastics.Hysteresis was detected in the adsorption/desorption of bisphenols in a water environment,but no adsorption/desorption hysteresis was observed in the simulated intestinal conditions of warm-blooded organisms.Due to enhanced bioaccessibility,the desorption results imply that the environmental risk of contaminated PVC microplastics may be significantly increased after ingestion at a high bisphenols dosage.Although with different IC_(50),the five bisphenols released under the intestinal conditions of warm-blooded organisms can cause higher proliferation reduction in fish and human cell lines than the bisphenols released in water.This study helps elucidate the consequential fate and potential cytotoxicity of contaminated microplastics and the possible implications of the microplastics as a critical vector for bisphenols to increase the potential health risks.
