The escalating demand for lithium-ion batteries highlights the critical need for alternative lithium sources beyond limited terrestrial reserves.Seawater offers a promising yet challenging lithium resource due to its ...The escalating demand for lithium-ion batteries highlights the critical need for alternative lithium sources beyond limited terrestrial reserves.Seawater offers a promising yet challenging lithium resource due to its sub-ppm level Li+concentration and the presence of competing cations(Na+,K+,Mg2+,and Ca2+).Here,we present a multilayer graphene membrane decorated withα-phase Al_(2)O_(3) networks(α-Al_(2)O_(3)/MLG)as a selective and durable platform for lithium extraction from seawater.This membrane leverages van der Waals gaps at Al_(2)O_(3)–MLG heterointerfaces and vertical channels formed at MLG grain boundary defects to achieve high Li+selectivity.By integrating the membrane into an electrodialysis system,a stable Li+flux of 0.084 mol h m^(-2) was maintained over 100 h,which resulted in lithium purity and recovery rates of 88.9%and 88.6%from artificial seawater over three extraction cycles.These findings demonstrate the membrane’s potential for selective lithium extraction from seawater while minimizing competing ion transport.展开更多
The competing reactions between existing Ni silicides surrounded by Si and Ni were investigated by thermal annealing and MeV Si ion beam mixing. With high energy irradiation, the energy deposition at both interfaces, ...The competing reactions between existing Ni silicides surrounded by Si and Ni were investigated by thermal annealing and MeV Si ion beam mixing. With high energy irradiation, the energy deposition at both interfaces, Ni/Ni silicide and Ni silicide/Si, is equal. Two MeV He^- RBS and TEM were used to obtain the reacted layer composition and epitaxial orientation, respectively. Also glancing angle Co K_a. X-ray diffraction was utilized to identify phase formation. The main results indicate that the existing silicides preferentially react with Ni layer, and that there are pronounced differences of Ni silicide phase transition between thermal annealing and MeV Si ion beam mixing, even though the mixing was performed in radiation enhanced diffusion regime. The results can be explained in term of the heat of silicide formation and surface energy change.展开更多
Yellow-emitting BCNO phosphors,applied for white light-emitting-diodes（LEDs）,were synthesized by a facile microwave heating route at lower temperature within short duration.The prepared BCNO phosphors exhibited amor...Yellow-emitting BCNO phosphors,applied for white light-emitting-diodes（LEDs）,were synthesized by a facile microwave heating route at lower temperature within short duration.The prepared BCNO phosphors exhibited amorphous form and tunable yellow emission in the range of 510–550 nm under the excitation of 450-nm blue light.The effects of carbon content on the photoluminescence properties for these BCNO phosphors and their application performances in white LEDs were investigated in detail.The demonstrated microwave synthesis route is promising in preparing low-cost phosphors,and the prepared BCNO phosphor may find potential application in blue-based white LEDs.展开更多
In this paper,we perform two-layer high-throughput calculations.In the first layer,which involves changing the crystal structure and/or chemical composition,we analyze selected Ⅲ-Ⅴ semiconductors,filled and unfilled...In this paper,we perform two-layer high-throughput calculations.In the first layer,which involves changing the crystal structure and/or chemical composition,we analyze selected Ⅲ-Ⅴ semiconductors,filled and unfilled skutterudites,as well as rock salt and layered chalcogenides.The second layer searches the full Brillouin zone(BZ)for critical points within 1.5 eV(1 eV=1.602176×10^(-19)J)of the Fermi level and characterizes those points by computing the effective masses.We introduce several methods to compute the effective masses from first principles and compare them to each other.Our approach also includes the calculation of the density-of-states effective masses for warped critical points,where traditional approaches fail to give consistent results due to an underlying non-analytic behavior of the critical point.We demonstrate the need to consider the band structure in its full complexity and the value of complementary approaches to compute the effective masses.We also provide computational evidence that warping occurs only in the presence of degeneracies.展开更多
High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlat...High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlation was developed for certain temperatures to find an equation for the relation between time and weight. The thermal treatment was done for different quantities at certain times. The proposed equation studies the correlation between temperature, time, and weight. For each temperature, a number of points were recorded from the measured oxidation curve. The shape of the curves is well-represented in this paper. The final results will present the highest temperature, the maximum weight, and the maximum time for full oxidation at high and low temperatures.展开更多
Recently, air pollution has become more serious and started to have a dramatic effect on the health of humans in many large cities. Generally, outdoor personal protection,such as commercial masks, cannot effectively p...Recently, air pollution has become more serious and started to have a dramatic effect on the health of humans in many large cities. Generally, outdoor personal protection,such as commercial masks, cannot effectively prevent the inhalation of many pollutants. Particulate matter(PM) pollutants are a particularly serious threat to human health. Here we introduce a new efficient air filtration mat that can be used for outdoor protection. The new efficient air filter’s nanocomposite materials were successfully fabricated from poly(ε-caprolactone)/polyethylene oxide(PCL/PEO) using an electrospinning technique and solvent vapor annealing(SVA).SVA treatment endows the wrinkled fiber surface and enhances the PM2.5 capture capacity of protective masks. This nanowrinkled air filtration mat can effectively filter PM2.5 with a removal efficiency of 80.01% under seriously polluted conditions(PM2.5 particle concentration above 225 mg m-3).Our field test in Qinhuangdao indicated that the air filtration mat had a high PM2.5 removal efficiency under thick haze.Compared to commercial masks, the fabricated SVA-treated PCL/PEO air filter mat demonstrated a simpler and ecofriendly preparation process with excellent degradation characteristics, showing wide potential applications with a high filtration efficiency.展开更多
One of the most accurate approaches for calculating lattice thermal conductivity,κ_(l),is solving the Boltzmann transport equation starting from third-order anharmonic force constants.In addition to the underlying ap...One of the most accurate approaches for calculating lattice thermal conductivity,κ_(l),is solving the Boltzmann transport equation starting from third-order anharmonic force constants.In addition to the underlying approximations of ab-initio parameterization,two main challenges are associated with this path:high computational costs and lack of automation in the frameworks using this methodology,which affect the discovery rate of novel materials with ad-hoc properties.Here,the Automatic Anharmonic Phonon Library(AAPL)is presented.It efficiently computes interatomic force constants by making effective use of crystal symmetry analysis,it solves the Boltzmann transport equation to obtain κ_(l),and allows a fully integrated operation with minimum user intervention,a rational addition to the current high-throughput accelerated materials development framework AFLOW.An“experiment vs.theory”study of the approach is shown,comparing accuracy and speed with respect to other available packages,and for materials characterized by strong electron localization and correlation.Combining AAPL with the pseudo-hybrid functional ACBN0 is possible to improve accuracy without increasing computational requirements.展开更多
The correct calculation of formation enthalpy is one of the enablers of ab-initio computational materials design.For several classes of systems(e.g.oxides)standard density functional theory produces incorrect values.H...The correct calculation of formation enthalpy is one of the enablers of ab-initio computational materials design.For several classes of systems(e.g.oxides)standard density functional theory produces incorrect values.Here we propose the“coordination corrected enthalpies”method(CCE),based on the number of nearest neighbor cation–anion bonds,and also capable of correcting relative stability of polymorphs.CCE uses calculations employing the Perdew,Burke and Ernzerhof(PBE),local density approximation(LDA)and strongly constrained and appropriately normed(SCAN)exchange correlation functionals,in conjunction with a quasiharmonic Debye model to treat zero-point vibrational and thermal effects.The benchmark,performed on binary and ternary oxides(halides),shows very accurate room temperature results for all functionals,with the smallest mean absolute error of 27(24)meV/atom obtained with SCAN.The zero-point vibrational and thermal contributions to the formation enthalpies are small and with different signs—largely canceling each other.展开更多
基金supported by the National Research Foundation(NRF)of Korea Grant funded by the Ministry of Science,ICT and Future Planning of Korea(Nos.RS-2021-NR060087,RS-2024-00353762).
文摘The escalating demand for lithium-ion batteries highlights the critical need for alternative lithium sources beyond limited terrestrial reserves.Seawater offers a promising yet challenging lithium resource due to its sub-ppm level Li+concentration and the presence of competing cations(Na+,K+,Mg2+,and Ca2+).Here,we present a multilayer graphene membrane decorated withα-phase Al_(2)O_(3) networks(α-Al_(2)O_(3)/MLG)as a selective and durable platform for lithium extraction from seawater.This membrane leverages van der Waals gaps at Al_(2)O_(3)–MLG heterointerfaces and vertical channels formed at MLG grain boundary defects to achieve high Li+selectivity.By integrating the membrane into an electrodialysis system,a stable Li+flux of 0.084 mol h m^(-2) was maintained over 100 h,which resulted in lithium purity and recovery rates of 88.9%and 88.6%from artificial seawater over three extraction cycles.These findings demonstrate the membrane’s potential for selective lithium extraction from seawater while minimizing competing ion transport.
文摘The competing reactions between existing Ni silicides surrounded by Si and Ni were investigated by thermal annealing and MeV Si ion beam mixing. With high energy irradiation, the energy deposition at both interfaces, Ni/Ni silicide and Ni silicide/Si, is equal. Two MeV He^- RBS and TEM were used to obtain the reacted layer composition and epitaxial orientation, respectively. Also glancing angle Co K_a. X-ray diffraction was utilized to identify phase formation. The main results indicate that the existing silicides preferentially react with Ni layer, and that there are pronounced differences of Ni silicide phase transition between thermal annealing and MeV Si ion beam mixing, even though the mixing was performed in radiation enhanced diffusion regime. The results can be explained in term of the heat of silicide formation and surface energy change.
基金the financial support by the National Natural Science Foundation of China(Nos.50872091and 51102265)Program of Discipline Leader of Colleges and Universities(Tianjin,China)‘‘Foreign Experts’’Thousand Talents Program(Tianjin,China)
文摘Yellow-emitting BCNO phosphors,applied for white light-emitting-diodes（LEDs）,were synthesized by a facile microwave heating route at lower temperature within short duration.The prepared BCNO phosphors exhibited amorphous form and tunable yellow emission in the range of 510–550 nm under the excitation of 450-nm blue light.The effects of carbon content on the photoluminescence properties for these BCNO phosphors and their application performances in white LEDs were investigated in detail.The demonstrated microwave synthesis route is promising in preparing low-cost phosphors,and the prepared BCNO phosphor may find potential application in blue-based white LEDs.
基金financial support from the Vitreous State Laboratory。
文摘In this paper,we perform two-layer high-throughput calculations.In the first layer,which involves changing the crystal structure and/or chemical composition,we analyze selected Ⅲ-Ⅴ semiconductors,filled and unfilled skutterudites,as well as rock salt and layered chalcogenides.The second layer searches the full Brillouin zone(BZ)for critical points within 1.5 eV(1 eV=1.602176×10^(-19)J)of the Fermi level and characterizes those points by computing the effective masses.We introduce several methods to compute the effective masses from first principles and compare them to each other.Our approach also includes the calculation of the density-of-states effective masses for warped critical points,where traditional approaches fail to give consistent results due to an underlying non-analytic behavior of the critical point.We demonstrate the need to consider the band structure in its full complexity and the value of complementary approaches to compute the effective masses.We also provide computational evidence that warping occurs only in the presence of degeneracies.
文摘High temperature treatment of tungsten alloy of W-5wt.% TM （transition metals, TM = Ni, Fe, Cu, Co） nanopowder was run under different temperatures to cover the oxidation rate at different temperatures. The correlation was developed for certain temperatures to find an equation for the relation between time and weight. The thermal treatment was done for different quantities at certain times. The proposed equation studies the correlation between temperature, time, and weight. For each temperature, a number of points were recorded from the measured oxidation curve. The shape of the curves is well-represented in this paper. The final results will present the highest temperature, the maximum weight, and the maximum time for full oxidation at high and low temperatures.
基金supported by the National Natural Science Foundation of China (21473153 and 51771162)Support Program for the Top Young Talents of Hebei Province+2 种基金China Postdoctoral Science Foundation (2015M580214)Research Program of the College Science & Technology of Hebei Province (ZD2018091)the Scientific and Technological Research and Development Program of Qinhuangdao City (201701B004)
文摘Recently, air pollution has become more serious and started to have a dramatic effect on the health of humans in many large cities. Generally, outdoor personal protection,such as commercial masks, cannot effectively prevent the inhalation of many pollutants. Particulate matter(PM) pollutants are a particularly serious threat to human health. Here we introduce a new efficient air filtration mat that can be used for outdoor protection. The new efficient air filter’s nanocomposite materials were successfully fabricated from poly(ε-caprolactone)/polyethylene oxide(PCL/PEO) using an electrospinning technique and solvent vapor annealing(SVA).SVA treatment endows the wrinkled fiber surface and enhances the PM2.5 capture capacity of protective masks. This nanowrinkled air filtration mat can effectively filter PM2.5 with a removal efficiency of 80.01% under seriously polluted conditions(PM2.5 particle concentration above 225 mg m-3).Our field test in Qinhuangdao indicated that the air filtration mat had a high PM2.5 removal efficiency under thick haze.Compared to commercial masks, the fabricated SVA-treated PCL/PEO air filter mat demonstrated a simpler and ecofriendly preparation process with excellent degradation characteristics, showing wide potential applications with a high filtration efficiency.
基金support by the DOE(DE-AC02-05CH11231),specifically the Basic Energy Sciences program under Grant#EDCBEEpartial support by DOD-ONR(N00014-13-1-0635,N00014-11-1-0136,and N00014-15-1-2863)the Alexander von Humboldt Foundation for financial support(Fritz-Haber-Institut der Max-Planck-Gesellschaft,14195 Berlin-Dahlem,Germany).
文摘One of the most accurate approaches for calculating lattice thermal conductivity,κ_(l),is solving the Boltzmann transport equation starting from third-order anharmonic force constants.In addition to the underlying approximations of ab-initio parameterization,two main challenges are associated with this path:high computational costs and lack of automation in the frameworks using this methodology,which affect the discovery rate of novel materials with ad-hoc properties.Here,the Automatic Anharmonic Phonon Library(AAPL)is presented.It efficiently computes interatomic force constants by making effective use of crystal symmetry analysis,it solves the Boltzmann transport equation to obtain κ_(l),and allows a fully integrated operation with minimum user intervention,a rational addition to the current high-throughput accelerated materials development framework AFLOW.An“experiment vs.theory”study of the approach is shown,comparing accuracy and speed with respect to other available packages,and for materials characterized by strong electron localization and correlation.Combining AAPL with the pseudo-hybrid functional ACBN0 is possible to improve accuracy without increasing computational requirements.
基金Research supported by DOD-ONR(N00014-15-1-2863,N00014-15-1-2266,N00014-17-1-2090,N00014-16-1-2326,N00014-17-1-2876)R.F.acknowledges support from the Alexander von Humboldt foundation under the Feodor Lynen research fellowship+1 种基金C.O.acknowledges support from the National Science Foundation Graduate Research Fellowship under Grant no.DGF-1106401S.C.acknowledges financial support from the Alexander von Humboldt foundation.
文摘The correct calculation of formation enthalpy is one of the enablers of ab-initio computational materials design.For several classes of systems(e.g.oxides)standard density functional theory produces incorrect values.Here we propose the“coordination corrected enthalpies”method(CCE),based on the number of nearest neighbor cation–anion bonds,and also capable of correcting relative stability of polymorphs.CCE uses calculations employing the Perdew,Burke and Ernzerhof(PBE),local density approximation(LDA)and strongly constrained and appropriately normed(SCAN)exchange correlation functionals,in conjunction with a quasiharmonic Debye model to treat zero-point vibrational and thermal effects.The benchmark,performed on binary and ternary oxides(halides),shows very accurate room temperature results for all functionals,with the smallest mean absolute error of 27(24)meV/atom obtained with SCAN.The zero-point vibrational and thermal contributions to the formation enthalpies are small and with different signs—largely canceling each other.
