Carbonatites are commonly related to the accumulation of economically valuable substances such as REE, Cu, and P. The debate over the origin of carbonatites and their relationship to associated silicate rocks has been...Carbonatites are commonly related to the accumulation of economically valuable substances such as REE, Cu, and P. The debate over the origin of carbonatites and their relationship to associated silicate rocks has been ongoing for about 45 years, Worldwide, the rocks characteristically display more geochemical enrichments in Ba, Sr and REE than sedimentary carbonate rocks. However, carbonatite＇s geochemical features are disputed because of secondary mineral effects. Rock-forming carbonates from carbonatites at Qinling, Panxi region, and Bayan Obo in China show REE distribution patterns ranging from LREE enrichment to flat patterns. They are characterized by a Sr content more than 10 times higher than that of secondary carbonates. The coarse- and fine-grained dolomites from Bayan Obo H8 dolomite marbles also show similar high Sr abundance, indicating that they are of igneous origin. Some carbonates in Chinese carbonatites show REE （especially HREE） contents and distribution patterns similar to those of the whole rocks. These intrusive carbonatites display lower platinum group elements and stronger fractionation between Pt and lr relative to high-Si extrusive carbonatite. This indicates that most intrusive carbonatites may be carbonate cumulates. Maoniuping and Daluxiang in Panxi region are large REE deposits. Hydrothermal fluorite ore veins occur outside of the carbonatite bodies and are emplaced in wallrock syenite. The fluorite in Maoniuping has Sr and Nd isotopes similar to carbonatite. The Daluxiang fluorite shows Sr and REE compositions different from those in Maoniuping. The difference is reflected by both the carbonatites and rock-forming carbonates, indicating that REE mineralization is related to carbonatites. The cumulate processes of carbonate minerals make fractionated fluids rich in volatiles and LREE as a result of low partition coefficients for REE between carbonate and carbonatite melt and an increase from LREE to HREE. The carbonatite-derived fluid has interacted with wallrock to form REE ore veins. The amount of carbonatite dykes occurring near the Bayan Obo orebodies may support the same mineralization model, i.e. that fluids evolved from the carbonatite dykes reacted with H8 dolomite marble, and thus the different REE and isotope compositions of coarse- and fine-grained dolomite may be related to reaction processes.展开更多
Lactic acid bacteria(LAB)fermentation is the simplest and safest way of food preservation,and the use of probiotics in yoghurt could provide dairy products with unique flavors,textures and health benefits.In this stud...Lactic acid bacteria(LAB)fermentation is the simplest and safest way of food preservation,and the use of probiotics in yoghurt could provide dairy products with unique flavors,textures and health benefits.In this study,Lactobacillus bulgaricus,Streptococcus thermophilus,L.reuteri DSMZ 8533 and the potential probiotic strain L.plantarum A3 were used for the milk fermentation.Results found the texture properties such as hardness,consistency,and viscosity of the yoghurt were enhanced in the mixed culture condition.Furthermore,components like amino acid(leucine),vanilla(vanillin),C;(unsaturated fatty acids)were also accumulated in L.plantarum A3 fermented yoghut,which leads to the significant sensory profiling difference compared with the former plain yoghurt.All these results proved L.plantarum A3 is a potential probiotic stom winch could enhance the sensory and nutrition profiling of the fermented milk.Future work still needs to be done on the synergistic interaction between the traditional strains and the probiotics during the fermentation process.展开更多
The branching corrected surface hopping(BCSH)has been demonstrated as a robust approach to improve the performance of the traditional fewest switches surface hopping(FSSH)for nonadiabatic dynamics simulations of stand...The branching corrected surface hopping(BCSH)has been demonstrated as a robust approach to improve the performance of the traditional fewest switches surface hopping(FSSH)for nonadiabatic dynamics simulations of standard scattering problems[J.Chem.Phys.150,164101(2019)].Here,we study how reliable populations of both adiabatic and diabatic states can be interpreted from BCSH trajectories.Using exact quantum solutions and FSSH results as references,we investigate a series of one-dimensional two-level scattering models and illustrate that excellent timedependent populations can be obtained by BCSH.Especially,we show that different trajectory analysis strategies produce noticeable differences in different representations.Namely,the method based on active states performs better to get populations of adiabatic states,while the method based on wavefunctions produces more reliable results for populations of diabatic states.展开更多
Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the poten...Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the potential rangeρ=14 and the number of atoms N up to 400.All the putative global minima reported in the literature have been successfully reproduced with relatively high success ratios.Compared to the available results for N≤240 and several larger Morse clusters,new global minima(and local minima)with lower energies have been found out for N=164,175,188,193,194,197,239,246,260,318,and 389.Clusters with magic numbers are figured out through fitting the size-dependent global minimum energies.The cluster structures tend to be close-packed for short-range potential with large N.展开更多
The emergence of digital twin technology has provided new ideas for vehicle path planning.To address autonomous vehicles’path conflicts in park logistics and enhance the efficiency of logistics and distribution,an im...The emergence of digital twin technology has provided new ideas for vehicle path planning.To address autonomous vehicles’path conflicts in park logistics and enhance the efficiency of logistics and distribution,an improved A^(*)algorithm path planning method for autonomous vehicles based on digital twin technology in parks has been proposed.This method involves creating an environment map model of the park environment and designing a conflict-free path planning algorithm based on this model.An ambient dynamic time window,combined with an improved A^(*)algorithm,is used to plan conflict-free paths for autonomous vehicles.Simulation results demonstrate that this method reduces the average completion time for single-vehicle path planning tasks within the park by 33 seconds.Additionally,there is an average decrease of 16.40%in total task completion time and a 15.45%reduction in conflict adjustment time.The application of this method can improve the efficiency of logistics and distribution within the park,ultimately reducing the economic cost of transportation.展开更多
The twist angle between two van der Waals coupled monolayers has emerged as a new and powerful degree of freedom for engineering physical properties of semiconductor homo-and hetero-bilayers.While the interlayer twist...The twist angle between two van der Waals coupled monolayers has emerged as a new and powerful degree of freedom for engineering physical properties of semiconductor homo-and hetero-bilayers.While the interlayer twist has shown prominent effect on electronic and optical properties of transition metal dichalcogenide(TMD)bilayers,it remains unclear how it could be used to manipulate the exciton dynamics,especially exciton-exciton annihilation(EEA)process which is the dominant energy loss channel in TMDs under moderate to high exciton density due to strong Coulomb interaction.Herein,we show that the twist angle in TMD bilayers can act as an effective knob to control the EEA process.Specifically,EEA rate constant increases from 1° twisted WSe_(2) bilayers(0.026 cm^(2)/s)by more than twice to 32° twisted bilayers(0.053 cm2/s)and then drops again in 60° twisted bilayers(0.019 cm^(2)/s).This twist-angle dependence can be attributed to the energy difference between indirect and direct excitons arising from the interlayer interaction.Our work opens up the possibility of artificially managing the exciton dynamics in TMD materials for optoelectronic applications via interlayer twist angle.展开更多
In colloidal quantum dots(QDs),the geometries of surface ligands may play significant roles in tuning the electronic structure,optical spectra and exciton dynamics.We here propose an effective approach to build a dive...In colloidal quantum dots(QDs),the geometries of surface ligands may play significant roles in tuning the electronic structure,optical spectra and exciton dynamics.We here propose an effective approach to build a diverse dataset of small QDs,based on which the machine learning force field(MLFF)can be obtained based on the DeePMD framework and the energy of each atom is expressed based on the local atomic structure.Using the obtained QD force field(QDFF),molecular dynamics simulation of large zinc-blende CdSe QDs passivated by carboxylate ligands is successfully carried out,and the complex surface structure is extensively studied.We find that bridging,tilted,chelating and claw geometries are the major geometries of carboxylate ligands in CdSe QDs,and the alkyl chain length of ligands plays a significant role.The Markov state model is utilized to reveal the detailed geometry transformation channels.Due to the high performance of QDFF,the present approach is promising for systematic studies of large QDs with different kinds of ligands that can be synthesized in experiment.展开更多
Chloride solid electrolytes(SEs)have attracted widespread attention due to their high room-temperature ionic conductivity and excellent cathode compatibility.However,the conventionally selected central metal elements(...Chloride solid electrolytes(SEs)have attracted widespread attention due to their high room-temperature ionic conductivity and excellent cathode compatibility.However,the conventionally selected central metal elements(e.g.,In,Y and Ta)are usually rare and heavy,inevitably causing the high cost and high density of the obtained chloride SEs.Here,by choosing abundant and light Mg and Al as central metal elements,we develop a cheap and low density Li_(1.2)Mg_(0.95)Al_(0.3)Cl_(4)SE for high active material ratio in all solid state cathode.Partial replacement of Mg^(2+)by Al^(3+)in the framework yields vacancies and lowers the non-lithium metal ions occupancy at Mg/Li co-occupied 16d site,effectively relieving the blocking effects by Mg^(2+)in the pristine spinel Li_(2-2x)Mg_(1+x)Cl_(4).Thus,a significantly improved room-temperature conductivity of 3.08×10^(-4)S·cm^(-1)is achieved,two orders of magnitude higher than that of Li_(1.2)Mg_(1.4)Cl_(4).More attractively,its low density of only 1.98 g·cm-3 enables low SE mass ratio in cathodes(only 16 wt.%)with still effective electrolyte/cathode contact and lithium-ion conduction inside.When charged to potential of 4.30 V,the asfabricated Li_(1.2)Mg_(0.95)Al_(0.3)Cl_(4)-based solid lithium battery with uncoated NCM523 cathode can be cycled for over 100 cycles with a capacity retention of 86.68%at room temperature.展开更多
基金financially supported by the Chinese National Science Foundation(Nos. 40973040,40773021)the West Light Foundation of Chinese Academy of Sciences and the Young Talent Plan of Peking University to Xu
文摘Carbonatites are commonly related to the accumulation of economically valuable substances such as REE, Cu, and P. The debate over the origin of carbonatites and their relationship to associated silicate rocks has been ongoing for about 45 years, Worldwide, the rocks characteristically display more geochemical enrichments in Ba, Sr and REE than sedimentary carbonate rocks. However, carbonatite＇s geochemical features are disputed because of secondary mineral effects. Rock-forming carbonates from carbonatites at Qinling, Panxi region, and Bayan Obo in China show REE distribution patterns ranging from LREE enrichment to flat patterns. They are characterized by a Sr content more than 10 times higher than that of secondary carbonates. The coarse- and fine-grained dolomites from Bayan Obo H8 dolomite marbles also show similar high Sr abundance, indicating that they are of igneous origin. Some carbonates in Chinese carbonatites show REE （especially HREE） contents and distribution patterns similar to those of the whole rocks. These intrusive carbonatites display lower platinum group elements and stronger fractionation between Pt and lr relative to high-Si extrusive carbonatite. This indicates that most intrusive carbonatites may be carbonate cumulates. Maoniuping and Daluxiang in Panxi region are large REE deposits. Hydrothermal fluorite ore veins occur outside of the carbonatite bodies and are emplaced in wallrock syenite. The fluorite in Maoniuping has Sr and Nd isotopes similar to carbonatite. The Daluxiang fluorite shows Sr and REE compositions different from those in Maoniuping. The difference is reflected by both the carbonatites and rock-forming carbonates, indicating that REE mineralization is related to carbonatites. The cumulate processes of carbonate minerals make fractionated fluids rich in volatiles and LREE as a result of low partition coefficients for REE between carbonate and carbonatite melt and an increase from LREE to HREE. The carbonatite-derived fluid has interacted with wallrock to form REE ore veins. The amount of carbonatite dykes occurring near the Bayan Obo orebodies may support the same mineralization model, i.e. that fluids evolved from the carbonatite dykes reacted with H8 dolomite marble, and thus the different REE and isotope compositions of coarse- and fine-grained dolomite may be related to reaction processes.
基金supported by the National Natural Science Foundation of China[32072192,31901668,31671869]Key Research and Development Project of Zhejiang Province[2020C02042]+4 种基金the Natural Science Foundation of Zhejiang Province[LY19C200005]the Natural Science Foundation of Ningbo(202003N4129)the Open Project Program of the First-Class Bioengineering Disciplines in Zhejiang Province[KF2020007]the Graduate General Program of the Education Department in Zhejiang Province[Y202045625]the K.C.Wong Magna Fund in Ningbo University。
文摘Lactic acid bacteria(LAB)fermentation is the simplest and safest way of food preservation,and the use of probiotics in yoghurt could provide dairy products with unique flavors,textures and health benefits.In this study,Lactobacillus bulgaricus,Streptococcus thermophilus,L.reuteri DSMZ 8533 and the potential probiotic strain L.plantarum A3 were used for the milk fermentation.Results found the texture properties such as hardness,consistency,and viscosity of the yoghurt were enhanced in the mixed culture condition.Furthermore,components like amino acid(leucine),vanilla(vanillin),C;(unsaturated fatty acids)were also accumulated in L.plantarum A3 fermented yoghut,which leads to the significant sensory profiling difference compared with the former plain yoghurt.All these results proved L.plantarum A3 is a potential probiotic stom winch could enhance the sensory and nutrition profiling of the fermented milk.Future work still needs to be done on the synergistic interaction between the traditional strains and the probiotics during the fermentation process.
基金supported by the National Natural Science Foundation of China(No.21922305 and No.21873080)。
文摘The branching corrected surface hopping(BCSH)has been demonstrated as a robust approach to improve the performance of the traditional fewest switches surface hopping(FSSH)for nonadiabatic dynamics simulations of standard scattering problems[J.Chem.Phys.150,164101(2019)].Here,we study how reliable populations of both adiabatic and diabatic states can be interpreted from BCSH trajectories.Using exact quantum solutions and FSSH results as references,we investigate a series of one-dimensional two-level scattering models and illustrate that excellent timedependent populations can be obtained by BCSH.Especially,we show that different trajectory analysis strategies produce noticeable differences in different representations.Namely,the method based on active states performs better to get populations of adiabatic states,while the method based on wavefunctions produces more reliable results for populations of diabatic states.
基金supported by the National Natural Science Foundation of China(No.21803053)the Natural Science Foundation of Zhejiang Province,China(No.LY20B030005)the Open Project Fund of Key Laboratory of Excited-State Materials of Zhejiang Province。
文摘Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the potential rangeρ=14 and the number of atoms N up to 400.All the putative global minima reported in the literature have been successfully reproduced with relatively high success ratios.Compared to the available results for N≤240 and several larger Morse clusters,new global minima(and local minima)with lower energies have been found out for N=164,175,188,193,194,197,239,246,260,318,and 389.Clusters with magic numbers are figured out through fitting the size-dependent global minimum energies.The cluster structures tend to be close-packed for short-range potential with large N.
基金supported by National Key Research and Development Program of China(2022YFD2100201)Key R&D Specialization of Henan Province(231111241100)+1 种基金Projects of higher Education institutions in Henan Province(22A460010)High level Talent Fund Projects of Henan University of Technology(2021BS081).
文摘The emergence of digital twin technology has provided new ideas for vehicle path planning.To address autonomous vehicles’path conflicts in park logistics and enhance the efficiency of logistics and distribution,an improved A^(*)algorithm path planning method for autonomous vehicles based on digital twin technology in parks has been proposed.This method involves creating an environment map model of the park environment and designing a conflict-free path planning algorithm based on this model.An ambient dynamic time window,combined with an improved A^(*)algorithm,is used to plan conflict-free paths for autonomous vehicles.Simulation results demonstrate that this method reduces the average completion time for single-vehicle path planning tasks within the park by 33 seconds.Additionally,there is an average decrease of 16.40%in total task completion time and a 15.45%reduction in conflict adjustment time.The application of this method can improve the efficiency of logistics and distribution within the park,ultimately reducing the economic cost of transportation.
基金We thank the financial support from the National Natural Science Foundation of China(Nos.22022305,21773208,21922305,and 21873080)the Fundamental Research Funds for the Central Universities(No.2020XZZX002-06)National Key Research and Development Program of China(No.2017YFA0207700).
文摘The twist angle between two van der Waals coupled monolayers has emerged as a new and powerful degree of freedom for engineering physical properties of semiconductor homo-and hetero-bilayers.While the interlayer twist has shown prominent effect on electronic and optical properties of transition metal dichalcogenide(TMD)bilayers,it remains unclear how it could be used to manipulate the exciton dynamics,especially exciton-exciton annihilation(EEA)process which is the dominant energy loss channel in TMDs under moderate to high exciton density due to strong Coulomb interaction.Herein,we show that the twist angle in TMD bilayers can act as an effective knob to control the EEA process.Specifically,EEA rate constant increases from 1° twisted WSe_(2) bilayers(0.026 cm^(2)/s)by more than twice to 32° twisted bilayers(0.053 cm2/s)and then drops again in 60° twisted bilayers(0.019 cm^(2)/s).This twist-angle dependence can be attributed to the energy difference between indirect and direct excitons arising from the interlayer interaction.Our work opens up the possibility of artificially managing the exciton dynamics in TMD materials for optoelectronic applications via interlayer twist angle.
基金support from the National Natural Science Foundation of China(No.22273082)the High-Performance Computing Center in Department of Chemistry,Zhejiang University.
文摘In colloidal quantum dots(QDs),the geometries of surface ligands may play significant roles in tuning the electronic structure,optical spectra and exciton dynamics.We here propose an effective approach to build a diverse dataset of small QDs,based on which the machine learning force field(MLFF)can be obtained based on the DeePMD framework and the energy of each atom is expressed based on the local atomic structure.Using the obtained QD force field(QDFF),molecular dynamics simulation of large zinc-blende CdSe QDs passivated by carboxylate ligands is successfully carried out,and the complex surface structure is extensively studied.We find that bridging,tilted,chelating and claw geometries are the major geometries of carboxylate ligands in CdSe QDs,and the alkyl chain length of ligands plays a significant role.The Markov state model is utilized to reveal the detailed geometry transformation channels.Due to the high performance of QDFF,the present approach is promising for systematic studies of large QDs with different kinds of ligands that can be synthesized in experiment.
基金the National Natural Science Foundation of China(Nos.22325505,52073271,and 22305236)the USTC Research Funds of the Double First-Class Initiative(No.YD2060002034)+1 种基金the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP018)the China Postdoctoral Science Foundation(Nos.2023M733375 and 2023T160619).
文摘Chloride solid electrolytes(SEs)have attracted widespread attention due to their high room-temperature ionic conductivity and excellent cathode compatibility.However,the conventionally selected central metal elements(e.g.,In,Y and Ta)are usually rare and heavy,inevitably causing the high cost and high density of the obtained chloride SEs.Here,by choosing abundant and light Mg and Al as central metal elements,we develop a cheap and low density Li_(1.2)Mg_(0.95)Al_(0.3)Cl_(4)SE for high active material ratio in all solid state cathode.Partial replacement of Mg^(2+)by Al^(3+)in the framework yields vacancies and lowers the non-lithium metal ions occupancy at Mg/Li co-occupied 16d site,effectively relieving the blocking effects by Mg^(2+)in the pristine spinel Li_(2-2x)Mg_(1+x)Cl_(4).Thus,a significantly improved room-temperature conductivity of 3.08×10^(-4)S·cm^(-1)is achieved,two orders of magnitude higher than that of Li_(1.2)Mg_(1.4)Cl_(4).More attractively,its low density of only 1.98 g·cm-3 enables low SE mass ratio in cathodes(only 16 wt.%)with still effective electrolyte/cathode contact and lithium-ion conduction inside.When charged to potential of 4.30 V,the asfabricated Li_(1.2)Mg_(0.95)Al_(0.3)Cl_(4)-based solid lithium battery with uncoated NCM523 cathode can be cycled for over 100 cycles with a capacity retention of 86.68%at room temperature.
