The vertical distribution and migration of Cu,Zn,Pb,and Cd in two forest soil profiles near an industrial emission source were investigated using a high resolution sampling method together with reference element Ti.On...The vertical distribution and migration of Cu,Zn,Pb,and Cd in two forest soil profiles near an industrial emission source were investigated using a high resolution sampling method together with reference element Ti.One-meter soil profile was sectioned horizontally at 2 cm intervals in the first 40 cm,5 cm intervals in the next 40 cm,and 10 cm intervals in the last 20 cm.The migration distance and rate of heavy metals in the soil profiles were calculated according to their relative concentrations in the profiles,as calibrated by the reference element Ti.The enrichment of heavy metals appeared in the uppermost layer of the forest soil,and the soil heavy metal concentrations decreased down the profile until reaching their background values.The calculated average migration rates of Cd,Cu,Pb,and Zn were 0.70,0.33,0.37,and 0.76 cm year-1,respectively,which were comparable to other methods.A simulation model was proposed,which could well describe the distribution of Cu,Zn,Pb,and Cd in natural forest soils.展开更多
In this paper,the pricing of a Credit Default Swap(CDS)contract with multiple counterparties is considered.The pricing model takes into account the credit rating migration risk of the reference.It is a new model estab...In this paper,the pricing of a Credit Default Swap(CDS)contract with multiple counterparties is considered.The pricing model takes into account the credit rating migration risk of the reference.It is a new model established under the reduced form framework,where the intensity rates are assumed to have structural styles.We derive from it a non-linear partial differential equation system where both positive and negative correlations of counterparties and the references are considered via a single factor model.Then,an ADI(Alternating Direction Implicit)difference method is used to solve the partial differential equations by iteration.From the numerical results,the comparison of multi-counterparty CDS contract and the standard one are analyzed respectively.Moreover,the impact of default parameters on value of the contracts are discussed.展开更多
A three-dimensional numerical model of sand wave dynamics,incorporating the interaction of currents and waves at various angles,has been developed using the Regional Ocean Modeling System(ROMS).This model accounts for...A three-dimensional numerical model of sand wave dynamics,incorporating the interaction of currents and waves at various angles,has been developed using the Regional Ocean Modeling System(ROMS).This model accounts for both bedload and suspended load sediment transport under combined waves and current conditions.The investigation examines the influence of several key parameters,including the rotation angle of sand waves relative to the main current,tidal current velocity amplitude,residual current,water depth,wave height,wave period,and wave direction,on sand wave evolution.The growth rate and migration rate of sand waves decrease as their rotation angle increases.For rotation angles smaller than 15°,sand wave evolution can be effectively simulated by a vertical 2D model with an error within 10%.The numerical results demonstrate that variations in tidal current velocity amplitude or residual current affect both vertical growth and horizontal migration of sand waves.As tidal current velocity amplitude and residual current increase,the growth rate initially rises to a maximum before decreasing.The migration rate shows a consistent increase with increasing tidal current amplitude and residual current.Under combined waves and current,both growth and migration rates decrease as water depth increases.With increasing wave height and period,the growth rate and migration rate initially rise to maximum values before declining,while showing a consistent increase with wave height and period.The change rate of sand waves reaches its maximum when wave propagation aligns parallel to tidal currents,and reaches its minimum when wave propagation is perpendicular to the currents.This phenomenon can be explained by the fluctuation of total bed shear stress relative to the angle of interaction between waves and current.展开更多
Pinus koraiensis(Sieb.et Zucc.) is a coniferous tree species naturally distributed in northeastern China.However,the effects of gene flow on its genetic diversity and structure remain unclear.This study investigates t...Pinus koraiensis(Sieb.et Zucc.) is a coniferous tree species naturally distributed in northeastern China.However,the effects of gene flow on its genetic diversity and structure remain unclear.This study investigates these dynamics in seven populations using ten microsatellite markers.The results show a high level of genetic diversity within the populations(Ho=0.633,He=0.746).In addition,molecular analysis of variance(AMOVA) shows that 98% of genetic diversity occurs within populations,with minimal differentiation between populations(Fst=0.009-0.033).Gene flow analysis shows significant migration rates between specific population pairs,particularly C-TH(87%),LS-Y(69%) and TH-LS(69%),suggesting genetic homogenization.Bayesian clustering(STRUCTURE) supports admixture and weak population differentiation.Environmental factors,especially temperature-related variables,significantly influence genetic patterns.Partial Mantel tests and multiple matrix regression show strong correlations between genetic distance and adaptations to cold temperatures(bio6 and bio11).Overall,this study emphasizes the robust genetic diversification and high migration rates in the populations of P.koraiensis and highlights their resilience.These results emphasize the importance of incorporating genetic and ecological factors into conservation strategies for sustainable forest management.This research provides valuable insights into the complex interplay of genetic variation,gene flow and environmental influences in forest tree species and improves our understanding of their adaptive mechanisms.展开更多
[Objective] The deliver amount and deliver rate of heavy metal elements during smoking were studied, which could provide a reference for reducing the damage of cigarette products. [Method] Two pretreatment methodsof m...[Objective] The deliver amount and deliver rate of heavy metal elements during smoking were studied, which could provide a reference for reducing the damage of cigarette products. [Method] Two pretreatment methodsof microwave di- gestion and acid extraction were used to process the ash content, the total particu- late matter of mainstream smoke （TPM） and cigarette filter. Detection results of heavy metal elements were compared by the two methods. [Result] The microwave digestion method was better than acid solution extraction method on analysis of TPM, but presented disadvantages on analysis of ash and filter. Meanwhile, the migration amount and rate were studied and resultsshowed that most heavy metal elements were escaped along with sidestream smoke between 66.89% and 95.48%, and almost all Hg escaped through sidestream smoke. Other heavy metal elements, except Hg, were separately found in ash, TPM and filter. Cr, Ni, As and Se were mostly residual in ash, followed by TPM, and filter had the least, while Cd and Pb were just in the reverse order. Normally, 5% or less heavy metal elements were transferred to TPM, only a small part of which could reach 5%-10%. [Conclusion] Most of the heavy metal elements are taken by sidestream smoke, ash and filter, while the migration amounts to mainstream smoke are extremely low.展开更多
Radionuclide fallout during nuclear accidents on the land may impair the atmosphere, contaminate farmland soils and crops, and can even reach the groundwater. Previous research focused on the field distribution of dep...Radionuclide fallout during nuclear accidents on the land may impair the atmosphere, contaminate farmland soils and crops, and can even reach the groundwater. Previous research focused on the field distribution of deposited radionuclides in farmland soils, but details of the amounts of radionuclides in the plough layer and the changes in their proportional distribution in the soil profile with time are still inadequate. In this study, a lysimeter experiment was conducted to determine the vertical migration of 137Cs and 60Co in brown and aeolian sandy soils, collected from the farmlands adjoining Shidaowan Nuclear Power Plant(NPP) in eastern China, and to identify the factors influencing their migration depths in soil. At the end of the experiment(800 d), >96% of added 137Cs and 60Co were retained in the top 0–20 cm soil layer of both soils;very little 137Cs or 60Co initially migrated to 20–30 cm, but their amounts at this depth increased with time. The migration depth of 137Cs was greater in the aeolian sandy soil than in the brown soil during 0–577 d, but at the end of the experiment, 137Cs migrated to the same depth(25 cm) in both soils. Three phases on the vertical migration rate(v) of 60Co in the aeolian sandy soil can be identified: an initial rapid movement(0–355 d, v = 219 ± 17 mm year-1), followed by a steady movement(355–577 d, v = 150 ± 24 mm year-1) and a very slow movement(577–800 d, v = 107 ± 7 mm year-1). In contrast, its migration rate in the brown soil(v = 133 ± 17 mm year-1) was steady throughout the 800-d experimental period. The migration of both 137Cs and 60Co in the two soils appears to be regulated by soil clay and silt fractions that provide most of the soil surface area, soil organic carbon(SOC), and soil pH, which were manifested by the solid-liquid distribution coefficient of 137Cs and 60Co. The results of this study suggest that most 137Cs and 60Co remained within the top layer(0–20 cm depth) of farmland soils following a simulated NPP accident, and little reached the subsurface(20–30 cm depth). Fixation of radionuclides onto clay minerals may limit their migration in soil, but some could be laterally distributed by soil erosion and taken up by crops, and migrate into groundwater in a high water table level area after several decades.Remediation measures, therefore, should focus on reducing their impact on the farmland soils, crops, and water.展开更多
An important challenge facing K-ion batteries lies in exploring earth-abundant and safe cathode materials that can provide high capacity with high migration rate of K ions.Here,we propose a simple and efficient method...An important challenge facing K-ion batteries lies in exploring earth-abundant and safe cathode materials that can provide high capacity with high migration rate of K ions.Here,we propose a simple and efficient method for searching potential K cathode materials with first principles calculations.Our screening is based on combinations of weight capacity,K ion occupation ratio,volume change per K,and valence limit.With this screening method we predicted a series of potential K ions cathodes with favorable electrochemical performance,such as K_(2)VPO_(4)CO_(3)-like structures with 1 D diffusion channels,3 D channel structures K_(2)CoSiO_(4),layered materials KCoO_(2),KCrO_(2),KVF_(4) and K_(5)V_(3)F_(14),and others.These potential cathodes have small volume changes,suitable voltage,and high capacity,with small diffusion barriers.They may be useful in K-ion batteries with high energy density and rate performance.展开更多
Meandering rivers of various scales are found globally and exhibit a high degree of regularity in their evolutionary processes.This study utilized remote sensing interpretation techniques to extract and analyze the pl...Meandering rivers of various scales are found globally and exhibit a high degree of regularity in their evolutionary processes.This study utilized remote sensing interpretation techniques to extract and analyze the planform migration characteristics of meandering rivers.Specifically,remote sensing images of three meandering rivers—the Black and White Rivers in the Tibetan Plateau and the Itui River in the Amazon Basin—were selected for this analysis.By comparing these observations with existing research data,this study quantitatively revealed the lag response patterns in the planform migration processes of meandering rivers.The findings of the study revealed several key insights.(1)The average migration rates for the three rivers were determined to be 1.74,3.84,and 2.34 m/a,respectively.The critical values of the relative curvature radius for the river channels ranged from 1.5 to 2.0,1.7 to 2.2,and 2.5 to 3.0,where local migration rate peaks were observed.These findings align with previous research that reported critical values between 2.0 and 4.0.(2)A significant lag is observed in the migration rate relative to curvature in spatial variation,with lag distances for the Black,White,and Itui Rivers measuring 227,281,and 324 m,corresponding to 2.02,2.39,and 3.15 times the river width,respectively.(3)A comparison with other meandering rivers indicates that,despite significant variations in climatic and hydrological conditions and river discharges differing by over 1,000times,the ratio of lag distance to river width(relative lag distance)for meandering rivers consistently falls within the range of 2.0to 4.0.This study suggests that the establishment of critical values for the relative curvature radius and the concentration of the relative lag distance reflects distinct quantitative relationships that emerge during the evolutionary processes of meandering rivers,aiming to minimize energy expenditure.These relationships appear to be applicable to various types of alluvial rivers.展开更多
A pricing model for a corporate bond with rating migration risk is established in this article. With the technology of utility-indifference valuation under the Markov-modulated framework, we analyze the price of a mul...A pricing model for a corporate bond with rating migration risk is established in this article. With the technology of utility-indifference valuation under the Markov-modulated framework, we analyze the price of a multi-rating bond and obtain closed formulae in a three-rating case. Based on the pricing formulae, the impacts of the parameters on the indifference price are analyzed and some reasonable financial explanations are provided as well.展开更多
This research examines the shifts in age profiles among migrants in China,utilizing microdata derived from four national censuses and two 1%population sample surveys conducted since 1990.Our findings indicate:(1)there...This research examines the shifts in age profiles among migrants in China,utilizing microdata derived from four national censuses and two 1%population sample surveys conducted since 1990.Our findings indicate:(1)there has been a surge in age-specific migration intensity across all age groups over the past two decades;(2)the age profiles of the flow floating population differ from both the entire and the residual migrant populations;and(3)the age profiles of China’s flow floating population exhibit a blend of Asian and Western patterns-a prevalence among individuals in their early 20s,typical of Asian patterns,and a broad range of ages post-peak,indicative of Western patterns.Consequently,we propose that future population projections prioritize the flow floating population over the traditionally employed entire floating population.Furthermore,recognizing heterogeneity is critical for accurately understanding migrants in China,necessitating a comprehensive migration policy that safeguards the rights and welfare of these individuals.展开更多
Monte Carlo （MC） simulations, including multiple physical and chemical mechanisms, were performed to investigate the microstructure evolution of a conducting metal filament in a typical oxide-electrolyte-based ReRAM...Monte Carlo （MC） simulations, including multiple physical and chemical mechanisms, were performed to investigate the microstructure evolution of a conducting metal filament in a typical oxide-electrolyte-based ReRAM. It has been revealed that the growth direction and geometry of the conductive filament are controlled by the ion migration rate in the electrolyte layer during the formation procedure. When the migration rate is rela- tive high, the filament is shown to grow from cathode to anode. When the migration rate is low, the growth direction is expected to start from the anode. Simulated conductive filament （CF） geometries and I-V characteristics are also illustrated and analyzed. A good agreement between the simulation results and experiment data is obtained.展开更多
基金the National Natural Science Foundation of China (No40625001)the Knowledge Innovation Pro-gram of the Chinese Academy of Sciences (NoKZCX2-YW-409)the Jiangsu Provincial Natural Science Foundation of China (NoBK2004167)
文摘The vertical distribution and migration of Cu,Zn,Pb,and Cd in two forest soil profiles near an industrial emission source were investigated using a high resolution sampling method together with reference element Ti.One-meter soil profile was sectioned horizontally at 2 cm intervals in the first 40 cm,5 cm intervals in the next 40 cm,and 10 cm intervals in the last 20 cm.The migration distance and rate of heavy metals in the soil profiles were calculated according to their relative concentrations in the profiles,as calibrated by the reference element Ti.The enrichment of heavy metals appeared in the uppermost layer of the forest soil,and the soil heavy metal concentrations decreased down the profile until reaching their background values.The calculated average migration rates of Cd,Cu,Pb,and Zn were 0.70,0.33,0.37,and 0.76 cm year-1,respectively,which were comparable to other methods.A simulation model was proposed,which could well describe the distribution of Cu,Zn,Pb,and Cd in natural forest soils.
基金Supported by the National Natural Science Foundation of China(11671301,12071349).
文摘In this paper,the pricing of a Credit Default Swap(CDS)contract with multiple counterparties is considered.The pricing model takes into account the credit rating migration risk of the reference.It is a new model established under the reduced form framework,where the intensity rates are assumed to have structural styles.We derive from it a non-linear partial differential equation system where both positive and negative correlations of counterparties and the references are considered via a single factor model.Then,an ADI(Alternating Direction Implicit)difference method is used to solve the partial differential equations by iteration.From the numerical results,the comparison of multi-counterparty CDS contract and the standard one are analyzed respectively.Moreover,the impact of default parameters on value of the contracts are discussed.
基金the National Natural Science Foundation of China(Grant Nos.52371289 and 51979192).
文摘A three-dimensional numerical model of sand wave dynamics,incorporating the interaction of currents and waves at various angles,has been developed using the Regional Ocean Modeling System(ROMS).This model accounts for both bedload and suspended load sediment transport under combined waves and current conditions.The investigation examines the influence of several key parameters,including the rotation angle of sand waves relative to the main current,tidal current velocity amplitude,residual current,water depth,wave height,wave period,and wave direction,on sand wave evolution.The growth rate and migration rate of sand waves decrease as their rotation angle increases.For rotation angles smaller than 15°,sand wave evolution can be effectively simulated by a vertical 2D model with an error within 10%.The numerical results demonstrate that variations in tidal current velocity amplitude or residual current affect both vertical growth and horizontal migration of sand waves.As tidal current velocity amplitude and residual current increase,the growth rate initially rises to a maximum before decreasing.The migration rate shows a consistent increase with increasing tidal current amplitude and residual current.Under combined waves and current,both growth and migration rates decrease as water depth increases.With increasing wave height and period,the growth rate and migration rate initially rise to maximum values before declining,while showing a consistent increase with wave height and period.The change rate of sand waves reaches its maximum when wave propagation aligns parallel to tidal currents,and reaches its minimum when wave propagation is perpendicular to the currents.This phenomenon can be explained by the fluctuation of total bed shear stress relative to the angle of interaction between waves and current.
基金funded by grants from the Innovation Project of the State Key Laboratory of Tree Genetics and Breeding(2021B01).
文摘Pinus koraiensis(Sieb.et Zucc.) is a coniferous tree species naturally distributed in northeastern China.However,the effects of gene flow on its genetic diversity and structure remain unclear.This study investigates these dynamics in seven populations using ten microsatellite markers.The results show a high level of genetic diversity within the populations(Ho=0.633,He=0.746).In addition,molecular analysis of variance(AMOVA) shows that 98% of genetic diversity occurs within populations,with minimal differentiation between populations(Fst=0.009-0.033).Gene flow analysis shows significant migration rates between specific population pairs,particularly C-TH(87%),LS-Y(69%) and TH-LS(69%),suggesting genetic homogenization.Bayesian clustering(STRUCTURE) supports admixture and weak population differentiation.Environmental factors,especially temperature-related variables,significantly influence genetic patterns.Partial Mantel tests and multiple matrix regression show strong correlations between genetic distance and adaptations to cold temperatures(bio6 and bio11).Overall,this study emphasizes the robust genetic diversification and high migration rates in the populations of P.koraiensis and highlights their resilience.These results emphasize the importance of incorporating genetic and ecological factors into conservation strategies for sustainable forest management.This research provides valuable insights into the complex interplay of genetic variation,gene flow and environmental influences in forest tree species and improves our understanding of their adaptive mechanisms.
文摘[Objective] The deliver amount and deliver rate of heavy metal elements during smoking were studied, which could provide a reference for reducing the damage of cigarette products. [Method] Two pretreatment methodsof microwave di- gestion and acid extraction were used to process the ash content, the total particu- late matter of mainstream smoke （TPM） and cigarette filter. Detection results of heavy metal elements were compared by the two methods. [Result] The microwave digestion method was better than acid solution extraction method on analysis of TPM, but presented disadvantages on analysis of ash and filter. Meanwhile, the migration amount and rate were studied and resultsshowed that most heavy metal elements were escaped along with sidestream smoke between 66.89% and 95.48%, and almost all Hg escaped through sidestream smoke. Other heavy metal elements, except Hg, were separately found in ash, TPM and filter. Cr, Ni, As and Se were mostly residual in ash, followed by TPM, and filter had the least, while Cd and Pb were just in the reverse order. Normally, 5% or less heavy metal elements were transferred to TPM, only a small part of which could reach 5%-10%. [Conclusion] Most of the heavy metal elements are taken by sidestream smoke, ash and filter, while the migration amounts to mainstream smoke are extremely low.
基金the IAEA Project (No. 18176)the National Science and Technology Major Projects of China (No. 2013ZX06002001) that supported this workpart of the project supported by the National Key Research and Development Program of China (No. 2017YFC0505402)。
文摘Radionuclide fallout during nuclear accidents on the land may impair the atmosphere, contaminate farmland soils and crops, and can even reach the groundwater. Previous research focused on the field distribution of deposited radionuclides in farmland soils, but details of the amounts of radionuclides in the plough layer and the changes in their proportional distribution in the soil profile with time are still inadequate. In this study, a lysimeter experiment was conducted to determine the vertical migration of 137Cs and 60Co in brown and aeolian sandy soils, collected from the farmlands adjoining Shidaowan Nuclear Power Plant(NPP) in eastern China, and to identify the factors influencing their migration depths in soil. At the end of the experiment(800 d), >96% of added 137Cs and 60Co were retained in the top 0–20 cm soil layer of both soils;very little 137Cs or 60Co initially migrated to 20–30 cm, but their amounts at this depth increased with time. The migration depth of 137Cs was greater in the aeolian sandy soil than in the brown soil during 0–577 d, but at the end of the experiment, 137Cs migrated to the same depth(25 cm) in both soils. Three phases on the vertical migration rate(v) of 60Co in the aeolian sandy soil can be identified: an initial rapid movement(0–355 d, v = 219 ± 17 mm year-1), followed by a steady movement(355–577 d, v = 150 ± 24 mm year-1) and a very slow movement(577–800 d, v = 107 ± 7 mm year-1). In contrast, its migration rate in the brown soil(v = 133 ± 17 mm year-1) was steady throughout the 800-d experimental period. The migration of both 137Cs and 60Co in the two soils appears to be regulated by soil clay and silt fractions that provide most of the soil surface area, soil organic carbon(SOC), and soil pH, which were manifested by the solid-liquid distribution coefficient of 137Cs and 60Co. The results of this study suggest that most 137Cs and 60Co remained within the top layer(0–20 cm depth) of farmland soils following a simulated NPP accident, and little reached the subsurface(20–30 cm depth). Fixation of radionuclides onto clay minerals may limit their migration in soil, but some could be laterally distributed by soil erosion and taken up by crops, and migrate into groundwater in a high water table level area after several decades.Remediation measures, therefore, should focus on reducing their impact on the farmland soils, crops, and water.
基金supported by the National Key R&D Program of China(Grant No.2016YFA0200400)the National Natural Science Foundation of China(Grant No.11504123 and No.51627805)。
文摘An important challenge facing K-ion batteries lies in exploring earth-abundant and safe cathode materials that can provide high capacity with high migration rate of K ions.Here,we propose a simple and efficient method for searching potential K cathode materials with first principles calculations.Our screening is based on combinations of weight capacity,K ion occupation ratio,volume change per K,and valence limit.With this screening method we predicted a series of potential K ions cathodes with favorable electrochemical performance,such as K_(2)VPO_(4)CO_(3)-like structures with 1 D diffusion channels,3 D channel structures K_(2)CoSiO_(4),layered materials KCoO_(2),KCrO_(2),KVF_(4) and K_(5)V_(3)F_(14),and others.These potential cathodes have small volume changes,suitable voltage,and high capacity,with small diffusion barriers.They may be useful in K-ion batteries with high energy density and rate performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2040215&52379079)。
文摘Meandering rivers of various scales are found globally and exhibit a high degree of regularity in their evolutionary processes.This study utilized remote sensing interpretation techniques to extract and analyze the planform migration characteristics of meandering rivers.Specifically,remote sensing images of three meandering rivers—the Black and White Rivers in the Tibetan Plateau and the Itui River in the Amazon Basin—were selected for this analysis.By comparing these observations with existing research data,this study quantitatively revealed the lag response patterns in the planform migration processes of meandering rivers.The findings of the study revealed several key insights.(1)The average migration rates for the three rivers were determined to be 1.74,3.84,and 2.34 m/a,respectively.The critical values of the relative curvature radius for the river channels ranged from 1.5 to 2.0,1.7 to 2.2,and 2.5 to 3.0,where local migration rate peaks were observed.These findings align with previous research that reported critical values between 2.0 and 4.0.(2)A significant lag is observed in the migration rate relative to curvature in spatial variation,with lag distances for the Black,White,and Itui Rivers measuring 227,281,and 324 m,corresponding to 2.02,2.39,and 3.15 times the river width,respectively.(3)A comparison with other meandering rivers indicates that,despite significant variations in climatic and hydrological conditions and river discharges differing by over 1,000times,the ratio of lag distance to river width(relative lag distance)for meandering rivers consistently falls within the range of 2.0to 4.0.This study suggests that the establishment of critical values for the relative curvature radius and the concentration of the relative lag distance reflects distinct quantitative relationships that emerge during the evolutionary processes of meandering rivers,aiming to minimize energy expenditure.These relationships appear to be applicable to various types of alluvial rivers.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant No. 11271287）.
文摘A pricing model for a corporate bond with rating migration risk is established in this article. With the technology of utility-indifference valuation under the Markov-modulated framework, we analyze the price of a multi-rating bond and obtain closed formulae in a three-rating case. Based on the pricing formulae, the impacts of the parameters on the indifference price are analyzed and some reasonable financial explanations are provided as well.
基金Funding was provided by National Planning Office of Philosophy and Social Science(Grant no.19BRK039).
文摘This research examines the shifts in age profiles among migrants in China,utilizing microdata derived from four national censuses and two 1%population sample surveys conducted since 1990.Our findings indicate:(1)there has been a surge in age-specific migration intensity across all age groups over the past two decades;(2)the age profiles of the flow floating population differ from both the entire and the residual migrant populations;and(3)the age profiles of China’s flow floating population exhibit a blend of Asian and Western patterns-a prevalence among individuals in their early 20s,typical of Asian patterns,and a broad range of ages post-peak,indicative of Western patterns.Consequently,we propose that future population projections prioritize the flow floating population over the traditionally employed entire floating population.Furthermore,recognizing heterogeneity is critical for accurately understanding migrants in China,necessitating a comprehensive migration policy that safeguards the rights and welfare of these individuals.
基金Project supported by the Ministry of Science and Technology of China(Nos.2010CB934200,2011CBA00602,2009CB930803,2011CB921804,2011AA010401,2011AA010402,XDA06020102)the National Natural Science Foundation of China(Nos.61221004,61274091,60825403,61106119,61106082,61306117)
文摘Monte Carlo （MC） simulations, including multiple physical and chemical mechanisms, were performed to investigate the microstructure evolution of a conducting metal filament in a typical oxide-electrolyte-based ReRAM. It has been revealed that the growth direction and geometry of the conductive filament are controlled by the ion migration rate in the electrolyte layer during the formation procedure. When the migration rate is rela- tive high, the filament is shown to grow from cathode to anode. When the migration rate is low, the growth direction is expected to start from the anode. Simulated conductive filament （CF） geometries and I-V characteristics are also illustrated and analyzed. A good agreement between the simulation results and experiment data is obtained.
