Globally,many lakes are drying up,leaving exposed lakebeds where wind erosion releases dust and sand rich in salt and harmful heavy metals into the atmosphere.Therefore,understanding the characteristics and spatial di...Globally,many lakes are drying up,leaving exposed lakebeds where wind erosion releases dust and sand rich in salt and harmful heavy metals into the atmosphere.Therefore,understanding the characteristics and spatial distribution of playa surface crusts is important to recognize the manifestation of salt dust storms.The objective of this study was to explore the playa surface crust types as well as their spatial distribution and evolution of Qehan Lake in Inner Mongolia Autonomous Region,China to understand the salt dust release potential of different types of playa surface crusts.Various crust characteristics were investigated by field sampling in Qehan Lake,and playa surface crusts were further divided into five types:vegetated areas,salt crusts,clay flats,curly crusts,and margins.It should be noted that curly crusts were distributed in clay flats and covered only a small area in Qehan Lake.The spatial distribution characteristics of playa surface crust types were obtained by supervised classification of remote sensing images,and the salt dust release potential of crusts was explored by the wind tunnel experiments.The field investigation of Qehan Lake revealed that playa surface crust types had a circum-lake band distribution from the inside to the outside of this lake,which were successively vegetated areas,clay flats,salt crusts,and margins.The spatial distribution patterns of playa surface crust types were mainly controlled by the hydrodynamics of the playa,soil texture,and groundwater.There was a significant negative correlation between crust thickness and electrical conductivity.The results of the wind tunnel experiments showed that the initial threshold of friction wind velocity for the salt dust release was higher in clay flats(0.7–0.8 m/s)than in salt crusts(0.5–0.6 m/s).Moreover,the particle leap impact processes occurring under natural conditions may reduce this threshold value.Salinity was the main factor controlling the difference in the initial threshold of friction wind velocity for the salt dus展开更多
A Li/KNO_(3) composite(LKNO),with KNO_(3) uniformly implanted in bulk metallic Li,is fabricated for battery anode via a facile mechanical kneading approach,which exhibits high Coulombic efficiency and prolonged cycle ...A Li/KNO_(3) composite(LKNO),with KNO_(3) uniformly implanted in bulk metallic Li,is fabricated for battery anode via a facile mechanical kneading approach,which exhibits high Coulombic efficiency and prolonged cycle life.The mechanism behind the enhanced electrochemical performance of the“salt-in-metal”composite is investigated,where KNO_(3) in metallic Li composite electrode would be sustainably released into the electrolyte.The presence of NO_(3)-stabilizes the solid electrolyte interphase by producing functional Li_(3)N,LiNxOy,and Li_(2)O species.K^(+)from KNO_(3) also helps to form an electrostatic shield after its adsorption on the electrode protrusions,which suppresses the dendritic growth of metallic Li.With the above advantages,uniform Li plating with dense and planar structure is realized for the LKNO electrode.These findings reveal a deep understanding of the effect of the“saltin-metal”anode and provide new insights into the use of nitrate additives for high-energy-density Li metal batteries.展开更多
In coastal areas, excessive exploitation of groundwater causes seawater intrusion. In artificial recharge of aquifer remediation process, the replacement of saltwater and freshwater with each other causes colloid rele...In coastal areas, excessive exploitation of groundwater causes seawater intrusion. In artificial recharge of aquifer remediation process, the replacement of saltwater and freshwater with each other causes colloid release, and permeability also decreases. In this paper, the aquifer samples containing minimal clay mineral(mainly illite) in Dagu River aquifer were used. Adopting horizontal column experiments, we studied the influences of seepage velocity and ionic strength on particle release, as well as the relationship between them. In the column experiments, the Critical Salt Concentration(CSC) of the Dagu River aquifer was determined as 0.05 mol L^(-1) approximately. This result was basically consistent with the DLVO theoretical calculation. For the constant seepage velocity, the salinity descending rate and partical release were slower, and the peak of particle concentration was lower. However, the total amount of released particles was almost constant at different salinity descending rate. For constant salinity descending rates, the peak of particle concentration decreased as seepage velocity increased, but the total amount of released particles rose up. The experiments also indicated the existence of a critical seepage velocity, which dropped with the decrease of salt concentration. When the concentration of Na Cl solution decreased from 0.17 mol L^(-1) to 0.06 mol L^(-1), the critical seepage velocity decreased from 3 cm min^(-1)to 2.5 cm min^(-1), which is consistent to the results predicted by DLVO theory.展开更多
基金funded by the National Natural Science Foundation of China (42067013, 41571090)
文摘Globally,many lakes are drying up,leaving exposed lakebeds where wind erosion releases dust and sand rich in salt and harmful heavy metals into the atmosphere.Therefore,understanding the characteristics and spatial distribution of playa surface crusts is important to recognize the manifestation of salt dust storms.The objective of this study was to explore the playa surface crust types as well as their spatial distribution and evolution of Qehan Lake in Inner Mongolia Autonomous Region,China to understand the salt dust release potential of different types of playa surface crusts.Various crust characteristics were investigated by field sampling in Qehan Lake,and playa surface crusts were further divided into five types:vegetated areas,salt crusts,clay flats,curly crusts,and margins.It should be noted that curly crusts were distributed in clay flats and covered only a small area in Qehan Lake.The spatial distribution characteristics of playa surface crust types were obtained by supervised classification of remote sensing images,and the salt dust release potential of crusts was explored by the wind tunnel experiments.The field investigation of Qehan Lake revealed that playa surface crust types had a circum-lake band distribution from the inside to the outside of this lake,which were successively vegetated areas,clay flats,salt crusts,and margins.The spatial distribution patterns of playa surface crust types were mainly controlled by the hydrodynamics of the playa,soil texture,and groundwater.There was a significant negative correlation between crust thickness and electrical conductivity.The results of the wind tunnel experiments showed that the initial threshold of friction wind velocity for the salt dust release was higher in clay flats(0.7–0.8 m/s)than in salt crusts(0.5–0.6 m/s).Moreover,the particle leap impact processes occurring under natural conditions may reduce this threshold value.Salinity was the main factor controlling the difference in the initial threshold of friction wind velocity for the salt dus
基金Y.Sun acknowledges the financial support of the National Natural Science Foundation of China(No.52072137)Z.W.Seh acknowledges the support of the Singapore National Research Foundation(NRF-NRFF2017-04).
文摘A Li/KNO_(3) composite(LKNO),with KNO_(3) uniformly implanted in bulk metallic Li,is fabricated for battery anode via a facile mechanical kneading approach,which exhibits high Coulombic efficiency and prolonged cycle life.The mechanism behind the enhanced electrochemical performance of the“salt-in-metal”composite is investigated,where KNO_(3) in metallic Li composite electrode would be sustainably released into the electrolyte.The presence of NO_(3)-stabilizes the solid electrolyte interphase by producing functional Li_(3)N,LiNxOy,and Li_(2)O species.K^(+)from KNO_(3) also helps to form an electrostatic shield after its adsorption on the electrode protrusions,which suppresses the dendritic growth of metallic Li.With the above advantages,uniform Li plating with dense and planar structure is realized for the LKNO electrode.These findings reveal a deep understanding of the effect of the“saltin-metal”anode and provide new insights into the use of nitrate additives for high-energy-density Li metal batteries.
基金provided by the Natural Science Foundation of Shandong,China,under Grant No.ZR2014DL005Zhou Jun was supported by the China Scholarship Council+1 种基金provided by the National Natural Science Foundation of China(No.40902066)Key Project of Science and Technology of China(No.2013ZX07202-007)
文摘In coastal areas, excessive exploitation of groundwater causes seawater intrusion. In artificial recharge of aquifer remediation process, the replacement of saltwater and freshwater with each other causes colloid release, and permeability also decreases. In this paper, the aquifer samples containing minimal clay mineral(mainly illite) in Dagu River aquifer were used. Adopting horizontal column experiments, we studied the influences of seepage velocity and ionic strength on particle release, as well as the relationship between them. In the column experiments, the Critical Salt Concentration(CSC) of the Dagu River aquifer was determined as 0.05 mol L^(-1) approximately. This result was basically consistent with the DLVO theoretical calculation. For the constant seepage velocity, the salinity descending rate and partical release were slower, and the peak of particle concentration was lower. However, the total amount of released particles was almost constant at different salinity descending rate. For constant salinity descending rates, the peak of particle concentration decreased as seepage velocity increased, but the total amount of released particles rose up. The experiments also indicated the existence of a critical seepage velocity, which dropped with the decrease of salt concentration. When the concentration of Na Cl solution decreased from 0.17 mol L^(-1) to 0.06 mol L^(-1), the critical seepage velocity decreased from 3 cm min^(-1)to 2.5 cm min^(-1), which is consistent to the results predicted by DLVO theory.
