Recently,a new phase C'_(1) H_(2) hydrate was experimentally identified.In this work,the diffusive behaviors of H_(2) in C'_(1)phase clathrate hydrate are explored using classic molecular dynamics(MD)simulatio...Recently,a new phase C'_(1) H_(2) hydrate was experimentally identified.In this work,the diffusive behaviors of H_(2) in C'_(1)phase clathrate hydrate are explored using classic molecular dynamics(MD)simulations.It reveals that the cage occupancy by H_(2) molecule negligibly influences the C'_(1) phase clathrate structure but greatly dictates the diffusion coefficient of H_(2)molecule.Due to the small cage size and small windows connecting the neighboring cages in C'_(1) phase clathrate,nonoccupancy of the neighboring cages is demanded to enable the diffusion of H_(2) molecule that is primarily dominated by hopping mechanism.Moreover,the analysis of diffusive free energy landscape reveals lower energy barrier of H_(2) molecule in C'_(1) phase clathrate hydrate than that of other gases in conventional clathrate hydrates,and that H_(2) molecule travels through the windows between neighboring cages with preferential molecular orientation.This study provides critical physical insights into the diffusion behaviors of H_(2) in the C'_(1) phase clathrate hydrate,and implies that the C'_(1) clathrate hydrate is a promising solid structure for the next-generation H_(2) storage.展开更多
Thermo-electrochemical cells with inexpensive molten carbonate electrolyte and(CO2|O2) gas electrodes allow the possible conversion of high temperature waste heat from industrial processes into electricity.The cell co...Thermo-electrochemical cells with inexpensive molten carbonate electrolyte and(CO2|O2) gas electrodes allow the possible conversion of high temperature waste heat from industrial processes into electricity.The cell containing eutectic(Li,Na)2CO3 electrolyte with solid Mg O dispersion delivers a large Seebeck coefficient of-1.7 m V/K. At present, the(CO2|O2) gas electrodes use metallic gold as current collectors in order to avoid the formation of interfering oxide layers during operation. For further reduction in energy generation cost, the gold current collectors should be replaced with an inexpensive and stable alternative.In this study, the suitability of the(molten carbonate fuel cell) MCFC’s nickel-based cathodes to operate the molten-carbonate thermo-electrochemical cell, was investigated. Ni current collectors were examined in two different states, as Ni O and as lithiated Ni O(LixNi1-xO). The Ni O phase shows higher stability than the LixNi1-xO while the Seebeck coefficient remains above-1.2 m V/K.展开更多
Topological defects and smooth excitations determine the properties of systems showing collective order.We introduce a generic non-singular field theory that comprehensively describes defects and excitations in system...Topological defects and smooth excitations determine the properties of systems showing collective order.We introduce a generic non-singular field theory that comprehensively describes defects and excitations in systems with O(n)broken rotational symmetry.Within this formalism,we explore fast events,such as defect nucleation/annihilation and dynamical phase transitions where the interplay between topological defects and non-linear excitations is particularly important.To highlight its versatility,we apply this formalism in the context of Bose-Einstein condensates,active nematics,and crystal lattices.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12172314,11772278,and 11904300)the Jiangxi Provincial Outstanding Young Talents Program(Grant No.20192BCBL23029)+2 种基金the Fundamental Research Funds for the Central Universities(Xiamen University:Grant Nos.20720210025 and 20720220023)the Research Council of Norway(Grant No.262644)the 111 project(Grant No.B16029)。
文摘Recently,a new phase C'_(1) H_(2) hydrate was experimentally identified.In this work,the diffusive behaviors of H_(2) in C'_(1)phase clathrate hydrate are explored using classic molecular dynamics(MD)simulations.It reveals that the cage occupancy by H_(2) molecule negligibly influences the C'_(1) phase clathrate structure but greatly dictates the diffusion coefficient of H_(2)molecule.Due to the small cage size and small windows connecting the neighboring cages in C'_(1) phase clathrate,nonoccupancy of the neighboring cages is demanded to enable the diffusion of H_(2) molecule that is primarily dominated by hopping mechanism.Moreover,the analysis of diffusive free energy landscape reveals lower energy barrier of H_(2) molecule in C'_(1) phase clathrate hydrate than that of other gases in conventional clathrate hydrates,and that H_(2) molecule travels through the windows between neighboring cages with preferential molecular orientation.This study provides critical physical insights into the diffusion behaviors of H_(2) in the C'_(1) phase clathrate hydrate,and implies that the C'_(1) clathrate hydrate is a promising solid structure for the next-generation H_(2) storage.
基金the Research Council of Norway for financial support of the research project“Sustainable and Energy Efficient Electrochemical Production and Refining of Metals(SUPREME)”project no.228296 under the ENERGIX programthe Research Council of Norway for its Center of Excellence Funding scheme for Porelab,project no.262644。
文摘Thermo-electrochemical cells with inexpensive molten carbonate electrolyte and(CO2|O2) gas electrodes allow the possible conversion of high temperature waste heat from industrial processes into electricity.The cell containing eutectic(Li,Na)2CO3 electrolyte with solid Mg O dispersion delivers a large Seebeck coefficient of-1.7 m V/K. At present, the(CO2|O2) gas electrodes use metallic gold as current collectors in order to avoid the formation of interfering oxide layers during operation. For further reduction in energy generation cost, the gold current collectors should be replaced with an inexpensive and stable alternative.In this study, the suitability of the(molten carbonate fuel cell) MCFC’s nickel-based cathodes to operate the molten-carbonate thermo-electrochemical cell, was investigated. Ni current collectors were examined in two different states, as Ni O and as lithiated Ni O(LixNi1-xO). The Ni O phase shows higher stability than the LixNi1-xO while the Seebeck coefficient remains above-1.2 m V/K.
文摘Topological defects and smooth excitations determine the properties of systems showing collective order.We introduce a generic non-singular field theory that comprehensively describes defects and excitations in systems with O(n)broken rotational symmetry.Within this formalism,we explore fast events,such as defect nucleation/annihilation and dynamical phase transitions where the interplay between topological defects and non-linear excitations is particularly important.To highlight its versatility,we apply this formalism in the context of Bose-Einstein condensates,active nematics,and crystal lattices.
