The nucleation process of stick-slip instability was analyzed based on the experimental measurements of strain and fault slip on homogeneous and non-homogeneous faults. The results show that the nucleation process of ...The nucleation process of stick-slip instability was analyzed based on the experimental measurements of strain and fault slip on homogeneous and non-homogeneous faults. The results show that the nucleation process of stick-slip on the homogeneous fault is of weak slip-weakening behavior under constant loading point velocity. The existence of a short "weak segment" on the fault makes slip-weakening phenomenon in nucleation process more obvious, while the existence of a long "weak segment" on the fault makes the nucleation process changed. The nucleation is characterized by accelerating slip in a local region and rapid increase of shear stress along the fault in this case, which is more coincident with the rate and state friction law. During the period when fault is locked, increasing of shear stress causes lateral elastic dilation near the fault, and the rebound of the dilation at the time of instability causes an instantaneous increase of normal stress in the fault plane, which is an important factor making fault be rapidly locked and its strength recovered.展开更多
The chemistry of sulfur cycle contributes significantly to the atmospheric nucleation process,which is the first step of new particle formation(NPF).In the present study,cycloaddition reaction mechanism of sulfur trio...The chemistry of sulfur cycle contributes significantly to the atmospheric nucleation process,which is the first step of new particle formation(NPF).In the present study,cycloaddition reaction mechanism of sulfur trioxide(SO_(3))to hydrogen sulfide(H_(2)S)which is a typical air pollutant and toxic gas detrimental to the environment were comprehensively investigate through theoretical calculations and Atmospheric Cluster Dynamic Code simulations.Gas-phase stability and nucleation potential of the product thiosulfuric acid(H_(2)S_(2)O_(3),TSA)were further analyzed to evaluate its atmospheric impact.Without any catalysts,the H_(2)S+SO_(3)reaction is infeasible with a barrier of 24.2 kcal/mol.Atmospheric nucleation precursors formic acid(FA),sulfuric acid(SA),and water(H_(2)O)could effectively lower the reaction barriers as catalysts,even to a barrierless reaction with the efficiency of cis-SA>trans-FA>trans-SA>H_(2)O.Subsequently,the gas-phase stability of TSA was investigated.A hydrolysis reaction barrier of up to 61.4 kcal/mol alone with an endothermic isomerization reaction barrier of 5.1 kcal/mol under the catalytic effect of SA demonstrates the sufficient stability of TSA.Furthermore,topological and kinetic analysis were conducted to determine the nucleation potential of TSA.Atmospheric clusters formed by TSA and atmospheric nucleation precursors(SA,ammonia NH_(3),and dimethylamine DMA)were thermodynamically stable.Moreover,the gradually decreasing evaporation coefficients for TSA-base clusters,particularly for TSA-DMA,suggests that TSA may participate in NPF where the concentration of base molecules are relatively higher.The present new reaction mechanismmay contributes to a better understanding of atmospheric sulfur cycle and NPF.展开更多
The recovery of high-concentrations manganese(Mn)ion(tens of thousands of milligrams per liter)from hydrometallurgical tailing water poses considerable challenges,leading to resource wastage and environmental concerns...The recovery of high-concentrations manganese(Mn)ion(tens of thousands of milligrams per liter)from hydrometallurgical tailing water poses considerable challenges,leading to resource wastage and environmental concerns.To address this,this study proposes the nucleation crystallization pelleting process,a technique that facilitates the adherence of Mn ion onto the surface of specialized seeds,enabling the formation of nucleation pellets for recovery.A multistage series reactor was used under optimized conditions(particle sizes of 60-80 mesh,sodium carbonate dosage of 2500 mg/L influent pH of 3,and upflow velocity of 50 m/h).A stable and continuous operation of the reactor resulted in a Mn ion removal rate of>99%.Laser particle size analysis and scanning electron microscopy results revealed that seeds growth occurred progressively,forming a loose and porous surface structure that enhanced the attachment of manganese carbonate(MnCO_(3))particles.X-ray diffraction,X-ray photoelectron spectroscopy and zeta potential analyses results demonstrated that Mn ion predominantly adhered to seed surface in the form of MnCO_(3) with purity detection confirming nucleation pellets achieving a content of>95%.This study demonstrates the high efficiency and practical applicability of this nucleation crystallization pelleting process and highlights its potential to significantly reduce resource wastage and environmental impacts,offering a practical and effective solution for recovering high-concentrated Mn ion from hydrometallurgical tailing water.展开更多
The electrochemical behavior of lithium incorporated in aluminum electrode in LiTFSI/KTf （lithium bis （trifluoromethylsulfonyl） amide/CF3SO3K） molten salt electrolyte was studied by a variety of electrochemical te...The electrochemical behavior of lithium incorporated in aluminum electrode in LiTFSI/KTf （lithium bis （trifluoromethylsulfonyl） amide/CF3SO3K） molten salt electrolyte was studied by a variety of electrochemical techniques including cyclic voltammetry, chronopotentiometry and chronoamperometry. The reduction reaction is found involving a nucleation process on the aluminum electrode. The results of chronopotentiometry indicate that the process of lithium incorporation in aluminum is smooth and uniform. The galvanostatic cycle experiments show that the coulombic efficiency is very low in the first cycle, which is mainly due to the ＂retention capacity＂ of Li-Al alloys. This characteristic is testified by the results of XRD and SEM. The results of chronoamperometry indicate that the incorporation of lithium into aluminum for the formation of a-phase Li-Al alloy is limited by its diffusion rate, with a measured diffusion coefficient of 1.8× 10^-10 cm2/s.展开更多
The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor...The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.展开更多
The strong earthquakes in western Yunnan area, mainly occur along great interplate strike slip faults and have a dominant depth layer about 10～20 km; the seismic rupture is characterized by strike slip rupture. Co...The strong earthquakes in western Yunnan area, mainly occur along great interplate strike slip faults and have a dominant depth layer about 10～20 km; the seismic rupture is characterized by strike slip rupture. Considering the Yunnan lithospheric structure and dynamic background, we think that earthquakes occurring at this area might have such a kind of nucleation process: because of the multi layers and heterogeneities of lithospheric structure, a zone of concentrated shear strain or of slip might be formed at the moderate or deep portions of lithosphere, and spread upward along faulting boundary, toward the earths surface under the background field of tectonic movement of lithospheric plates. The slip front will encounter the maximum shear resistance zone on the fault surface in this process, be barried and blocked, and form a seismic gap. With the increase of tectonic load, this slip zone will continuously spread forward, traverse and lead to instable crack of the whole blocked zone, and cause a great earthquake. We have derived an approximate integral equation describing this seismic process; the numerical results show that the model has an instable nonlinear accelerating evolution period which might have important significance for the generation of earthquake precursors.展开更多
Materials and chemical scientists have tirelessly pursued the vision of creating atomically tailored materials.The promise of atomic precision in material synthesis lies in the potential to precisely control every asp...Materials and chemical scientists have tirelessly pursued the vision of creating atomically tailored materials.The promise of atomic precision in material synthesis lies in the potential to precisely control every aspect of a material's structure,thereby opening up opportunities for discovering and tuning novel physical properties[1].However,achieving atomically precise assemblies in practice remains a formidable challenge,largely due to the difficulty of controlling nucleation and growth processes at the most fundamental scale.展开更多
We constructed a more complete earthquake catalog in the 2021 Yangbi M6.4 focal area by re-scanning the continuous waveforms integrated with deep learning and template matching techniques,to explore the seismogenic st...We constructed a more complete earthquake catalog in the 2021 Yangbi M6.4 focal area by re-scanning the continuous waveforms integrated with deep learning and template matching techniques,to explore the seismogenic structures of the Yangbi mainshock and its nucleation process.The new catalog has three times the number of earthquakes than the CENC catalog,and the magnitude completeness has dropped from 1.1 to 0.5.The distribution of earthquakes indicates a broom-shaped structure consisting of several oblique secondary faults and a strike-slip main fault which strikes to 315°with 80°dipping to NE.The earthquakes extend along the fault strike about 27 km in width and 2-13 km at depth and have noticeable variations on seismicity in the mainshock’s north and south.Compared with the north,the south has denser and higher magnitude aftershocks and also has a seismic gap probably weakened by the fluid at the depth range of about 5-6 km.The foreshocks were mainly active in the 8-kilometer-long fault zone south of the mainshock,which show a steady drop in b-values over time and a migration pattern toward the epicenter of two steep jumps,stagnation,and then acceleration which finally triggered the mainshock.While in the north,seldom foreshock occurred,and the aftershocks were delayed triggered 3 hours after the mainshock,and sparsely scattered shallow at depth and small in magnitude.To summarize,the northern part of the Yangbi seismogenic fault is thought to be relatively locked,whereas the southern part has a weakening zone and promotes pre-slip.The nucleation mechanism of the mainshock and its onset at the junction of the locked and pre-slip zones may be a combination of pre-slip and cascade triggering.展开更多
文摘The nucleation process of stick-slip instability was analyzed based on the experimental measurements of strain and fault slip on homogeneous and non-homogeneous faults. The results show that the nucleation process of stick-slip on the homogeneous fault is of weak slip-weakening behavior under constant loading point velocity. The existence of a short "weak segment" on the fault makes slip-weakening phenomenon in nucleation process more obvious, while the existence of a long "weak segment" on the fault makes the nucleation process changed. The nucleation is characterized by accelerating slip in a local region and rapid increase of shear stress along the fault in this case, which is more coincident with the rate and state friction law. During the period when fault is locked, increasing of shear stress causes lateral elastic dilation near the fault, and the rebound of the dilation at the time of instability causes an instantaneous increase of normal stress in the fault plane, which is an important factor making fault be rapidly locked and its strength recovered.
基金supported by the Budget Surplus of Central Financial Science and Technology Plan (No.2021-JY-14)the Project funded by China Postdoctoral Science Foundation (No.2020M680636)+3 种基金the Fundamental Research Funds for Central Public Welfare Scientific Research Institutes of China,Chinese Research Academy of Environmental Sciences (Nos.2022YSKY-21 and 2022YSKY-27)the National Natural Science Foundation of China (No.41375133)the Science Foundation of Chinese Research Academy of Environmental Sciences (No.JY-41375133)Tian He Qingsuo Project-special fund project.
文摘The chemistry of sulfur cycle contributes significantly to the atmospheric nucleation process,which is the first step of new particle formation(NPF).In the present study,cycloaddition reaction mechanism of sulfur trioxide(SO_(3))to hydrogen sulfide(H_(2)S)which is a typical air pollutant and toxic gas detrimental to the environment were comprehensively investigate through theoretical calculations and Atmospheric Cluster Dynamic Code simulations.Gas-phase stability and nucleation potential of the product thiosulfuric acid(H_(2)S_(2)O_(3),TSA)were further analyzed to evaluate its atmospheric impact.Without any catalysts,the H_(2)S+SO_(3)reaction is infeasible with a barrier of 24.2 kcal/mol.Atmospheric nucleation precursors formic acid(FA),sulfuric acid(SA),and water(H_(2)O)could effectively lower the reaction barriers as catalysts,even to a barrierless reaction with the efficiency of cis-SA>trans-FA>trans-SA>H_(2)O.Subsequently,the gas-phase stability of TSA was investigated.A hydrolysis reaction barrier of up to 61.4 kcal/mol alone with an endothermic isomerization reaction barrier of 5.1 kcal/mol under the catalytic effect of SA demonstrates the sufficient stability of TSA.Furthermore,topological and kinetic analysis were conducted to determine the nucleation potential of TSA.Atmospheric clusters formed by TSA and atmospheric nucleation precursors(SA,ammonia NH_(3),and dimethylamine DMA)were thermodynamically stable.Moreover,the gradually decreasing evaporation coefficients for TSA-base clusters,particularly for TSA-DMA,suggests that TSA may participate in NPF where the concentration of base molecules are relatively higher.The present new reaction mechanismmay contributes to a better understanding of atmospheric sulfur cycle and NPF.
基金supported by the National Natural Science Foundation of China(No.52230001)the Project of Qinchuangyuan Platform“Scientist+Engineer”Team of Shaanxi Province,China(No.2023KXJ-149).
文摘The recovery of high-concentrations manganese(Mn)ion(tens of thousands of milligrams per liter)from hydrometallurgical tailing water poses considerable challenges,leading to resource wastage and environmental concerns.To address this,this study proposes the nucleation crystallization pelleting process,a technique that facilitates the adherence of Mn ion onto the surface of specialized seeds,enabling the formation of nucleation pellets for recovery.A multistage series reactor was used under optimized conditions(particle sizes of 60-80 mesh,sodium carbonate dosage of 2500 mg/L influent pH of 3,and upflow velocity of 50 m/h).A stable and continuous operation of the reactor resulted in a Mn ion removal rate of>99%.Laser particle size analysis and scanning electron microscopy results revealed that seeds growth occurred progressively,forming a loose and porous surface structure that enhanced the attachment of manganese carbonate(MnCO_(3))particles.X-ray diffraction,X-ray photoelectron spectroscopy and zeta potential analyses results demonstrated that Mn ion predominantly adhered to seed surface in the form of MnCO_(3) with purity detection confirming nucleation pellets achieving a content of>95%.This study demonstrates the high efficiency and practical applicability of this nucleation crystallization pelleting process and highlights its potential to significantly reduce resource wastage and environmental impacts,offering a practical and effective solution for recovering high-concentrated Mn ion from hydrometallurgical tailing water.
基金Project (70510011) supported by Scientific Research Starting Foundation of Jiaxing University,ChinaProject (84209001B3) supported by Open Fund of Key Laboratory of Clean Chemical Process of Jiaxing,China
文摘The electrochemical behavior of lithium incorporated in aluminum electrode in LiTFSI/KTf （lithium bis （trifluoromethylsulfonyl） amide/CF3SO3K） molten salt electrolyte was studied by a variety of electrochemical techniques including cyclic voltammetry, chronopotentiometry and chronoamperometry. The reduction reaction is found involving a nucleation process on the aluminum electrode. The results of chronopotentiometry indicate that the process of lithium incorporation in aluminum is smooth and uniform. The galvanostatic cycle experiments show that the coulombic efficiency is very low in the first cycle, which is mainly due to the ＂retention capacity＂ of Li-Al alloys. This characteristic is testified by the results of XRD and SEM. The results of chronoamperometry indicate that the incorporation of lithium into aluminum for the formation of a-phase Li-Al alloy is limited by its diffusion rate, with a measured diffusion coefficient of 1.8× 10^-10 cm2/s.
基金funded by the Natural Science Foundation of Shanghai(22ZR1428200)the National Natural Science Foundation of China(51950410581)+1 种基金the Shanghai Government(20JC141500)and CATL-SJTU joint funding.
文摘The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.
文摘The strong earthquakes in western Yunnan area, mainly occur along great interplate strike slip faults and have a dominant depth layer about 10～20 km; the seismic rupture is characterized by strike slip rupture. Considering the Yunnan lithospheric structure and dynamic background, we think that earthquakes occurring at this area might have such a kind of nucleation process: because of the multi layers and heterogeneities of lithospheric structure, a zone of concentrated shear strain or of slip might be formed at the moderate or deep portions of lithosphere, and spread upward along faulting boundary, toward the earths surface under the background field of tectonic movement of lithospheric plates. The slip front will encounter the maximum shear resistance zone on the fault surface in this process, be barried and blocked, and form a seismic gap. With the increase of tectonic load, this slip zone will continuously spread forward, traverse and lead to instable crack of the whole blocked zone, and cause a great earthquake. We have derived an approximate integral equation describing this seismic process; the numerical results show that the model has an instable nonlinear accelerating evolution period which might have important significance for the generation of earthquake precursors.
文摘Materials and chemical scientists have tirelessly pursued the vision of creating atomically tailored materials.The promise of atomic precision in material synthesis lies in the potential to precisely control every aspect of a material's structure,thereby opening up opportunities for discovering and tuning novel physical properties[1].However,achieving atomically precise assemblies in practice remains a formidable challenge,largely due to the difficulty of controlling nucleation and growth processes at the most fundamental scale.
基金supported by the National Natural Science Foundation of China(Grant Nos.41574050,41674058)the Project of Basic Scientific Research Foundation of Institute of Earthquake Forecasting,China Earthquake Administration(Grant Nos.2020IEF0602,2020IEF0504)the support of Academician Yong CHEN Workstation of Yunnan Province(Grant No.2014IC007)。
文摘We constructed a more complete earthquake catalog in the 2021 Yangbi M6.4 focal area by re-scanning the continuous waveforms integrated with deep learning and template matching techniques,to explore the seismogenic structures of the Yangbi mainshock and its nucleation process.The new catalog has three times the number of earthquakes than the CENC catalog,and the magnitude completeness has dropped from 1.1 to 0.5.The distribution of earthquakes indicates a broom-shaped structure consisting of several oblique secondary faults and a strike-slip main fault which strikes to 315°with 80°dipping to NE.The earthquakes extend along the fault strike about 27 km in width and 2-13 km at depth and have noticeable variations on seismicity in the mainshock’s north and south.Compared with the north,the south has denser and higher magnitude aftershocks and also has a seismic gap probably weakened by the fluid at the depth range of about 5-6 km.The foreshocks were mainly active in the 8-kilometer-long fault zone south of the mainshock,which show a steady drop in b-values over time and a migration pattern toward the epicenter of two steep jumps,stagnation,and then acceleration which finally triggered the mainshock.While in the north,seldom foreshock occurred,and the aftershocks were delayed triggered 3 hours after the mainshock,and sparsely scattered shallow at depth and small in magnitude.To summarize,the northern part of the Yangbi seismogenic fault is thought to be relatively locked,whereas the southern part has a weakening zone and promotes pre-slip.The nucleation mechanism of the mainshock and its onset at the junction of the locked and pre-slip zones may be a combination of pre-slip and cascade triggering.
