Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synt...Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synthesized two redox-active PAFs(PAF-305 and PAF-306)with different nitrogen-containing motifs,and demonstrated their application as cathode materials for SIBs.Density functional theory(DFT)calculations reveal that nitrogen-rich PAF-305 exhibits a lower lowest unoccupied molecular orbital(LUMO)energy level(-3.35 eV)and a narrower energy gap(E_(g))(2.40 eV)compared with nitrogen-poor PAF-306.As expected,PAF-305 displays outstanding electrochemical performance,comprising a high reversible capacity of 145.2 mAh g^(-1)at 0.05 A g^(-1)and satisfactory cycling stability with 92% capacity retention over 1000 cycles at 0.2 A g^(-1).Remarkably,PAF-305 maintains robust electrochemical properties across a wide temperature range(-20℃ to 50℃).Through a combination of experimental characterizations and theoretical calculations,the sodium-ion storage mechanism of PAF-305 is elucidated.This study not only provides a promising strategy for exploring other redox-active organic units in the design of novel PAFs,but also expands the potential applications of PAFs in energy storage systems.展开更多
The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave fr...The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave frequency w, and pitch angle diffusion coefficient Daa were calculated at the center location of the symmetrical ring current： r ≈3.5RE with RE the Earth＇s radius. Emin is found to decrease rapidly from 10 MeV to a few keV with the increase in ca in three bands： H^＋-band, He^＋-band and O^＋-band. Moreover, EMIC waves have substantial potential to scatter energetic （～100 keV） ions （mainly H^＋ and He^＋） into the loss cone and yield precipitation loss, suggesting that wave-particle interactions contribute to ring current decay.展开更多
Head-on collisions among the single-and multi-soliton’s heavy ion acoustic waves(HIAWs) of multi-ion plasma are studied. The plasma consists of adiabatic positively charged inertial heavy ions, Boltzmann energy distr...Head-on collisions among the single-and multi-soliton’s heavy ion acoustic waves(HIAWs) of multi-ion plasma are studied. The plasma consists of adiabatic positively charged inertial heavy ions, Boltzmann energy distributed light ions and kappa energy distributed electrons. The extended poincaré-Lighthill-Kuo(e PLK) method is applied for the derivation of two-sided Korteweg–de Vries(KdV) equations(KdVEs). The KdV single-soliton solutions(KdVSSs) are determined using the hyperbolic secant method and the KdV multi-soliton solutions(KdVMSs)are obtained using the Hirota method. The effects of superthermality of electrons, temperature ratios of electron to light ion and heavy ion to electron, and the density ratio of electron to heavy ion on phase shifts are investigated for the head-on collisions between two-soliton HIAWs. The effects of plasma parameters on angular frequency, phase speed, production of multi-soliton structures, and the head-on collisions among single-, double-, triple-, quadruple-, and quintuplesolitons are also studied.展开更多
We propose a scheme for generating multi-ion graph states using many trapped ions in thermal motion.Our generation scheme is insensitive to external state since the interaction between ions and laser fields does not i...We propose a scheme for generating multi-ion graph states using many trapped ions in thermal motion.Our generation scheme is insensitive to external state since the interaction between ions and laser fields does not involvethe external degree of freedom.The scheme can be well realized within the current experimental technique.展开更多
The nonlinear propagation of the DIA (dust ion-acoustic) waves in multi-ion dense plasma system containing degener- ate electrons, both positive and negative ions, arbitrary charged dust grains has been investigated b...The nonlinear propagation of the DIA (dust ion-acoustic) waves in multi-ion dense plasma system containing degener- ate electrons, both positive and negative ions, arbitrary charged dust grains has been investigated by employing the reductive perturbation method. The nonlinear waves (solitary and shock waves) have been observed to be formed in case of both positive and negative charged dust grains from the stationary solution of the Korteweg de-Vries (K-dV) equation and Burger’s equation. The fundamental properties of such nonlinear waves have been theoretically analyzed by comparing system potential for both positive and negative dust grains. It has been shown that the basic features of these waves are significantly modified by the positive and negative ions drift speed and polarities of dust grains. The implications of our results in space and laboratory plasmas are briefly discussed.展开更多
利用多组态Dirac-Hartree-Fock方法对类碳等电子序列(Z=10,14,32,36,50)1s^(2)2s^(2)2p^(2)和1s^(2)2s2p^(3)组态的能级结构和电偶极跃迁行为进行理论研究.在构建充分包含电子关联效应、规模适当的波函数后,考虑Breit相互作用、量子电...利用多组态Dirac-Hartree-Fock方法对类碳等电子序列(Z=10,14,32,36,50)1s^(2)2s^(2)2p^(2)和1s^(2)2s2p^(3)组态的能级结构和电偶极跃迁行为进行理论研究.在构建充分包含电子关联效应、规模适当的波函数后,考虑Breit相互作用、量子电动力学效应和原子核质量效应,比较分析了价-价关联效应、实-价关联效应和实-实关联效应对原子态激发能的影响,完成了原子态激发能的高精度理论计算.与其他理论结果相比,本文计算的Ne V离子的激发能结果与NIST(National Institute of Standards and Technology)数据最为接近;其他离子的激发能也具有较好的精度.在此基础上,结合LS耦合的原子态混合成分和NIST数据,对出现的原子态命名情况进行分析,推测了相应的原子态命名.本文还计算了组态间电偶极跃迁的谱线波长、跃迁速率、线强和加权振子强度,Ne V和Si IX离子的谱线波长与NIST数据符合得很好,相对误差小于0.62%;跃迁速率与其他理论结果比较一致.另外,本文计算得到的Babushkin和Coulomb两种规范的电偶极跃迁参数具有良好的一致性,进一步证明了本文采用的理论方法的准确性和可靠性.展开更多
基金supported by the Science&Technology Department of Jilin Province(20230508057RC)。
文摘Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synthesized two redox-active PAFs(PAF-305 and PAF-306)with different nitrogen-containing motifs,and demonstrated their application as cathode materials for SIBs.Density functional theory(DFT)calculations reveal that nitrogen-rich PAF-305 exhibits a lower lowest unoccupied molecular orbital(LUMO)energy level(-3.35 eV)and a narrower energy gap(E_(g))(2.40 eV)compared with nitrogen-poor PAF-306.As expected,PAF-305 displays outstanding electrochemical performance,comprising a high reversible capacity of 145.2 mAh g^(-1)at 0.05 A g^(-1)and satisfactory cycling stability with 92% capacity retention over 1000 cycles at 0.2 A g^(-1).Remarkably,PAF-305 maintains robust electrochemical properties across a wide temperature range(-20℃ to 50℃).Through a combination of experimental characterizations and theoretical calculations,the sodium-ion storage mechanism of PAF-305 is elucidated.This study not only provides a promising strategy for exploring other redox-active organic units in the design of novel PAFs,but also expands the potential applications of PAFs in energy storage systems.
基金National Natural Science Foundation of China (Nos.40874076,40774078,40774079 and 40536029)the Special Fund for Public Welfare Industry (meteorology)GYHY200806072the Visiting Scholar Foundation of State Key Laboratory for Space Weather,Chinese Academy of Sciences
文摘The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave frequency w, and pitch angle diffusion coefficient Daa were calculated at the center location of the symmetrical ring current： r ≈3.5RE with RE the Earth＇s radius. Emin is found to decrease rapidly from 10 MeV to a few keV with the increase in ca in three bands： H^＋-band, He^＋-band and O^＋-band. Moreover, EMIC waves have substantial potential to scatter energetic （～100 keV） ions （mainly H^＋ and He^＋） into the loss cone and yield precipitation loss, suggesting that wave-particle interactions contribute to ring current decay.
文摘Head-on collisions among the single-and multi-soliton’s heavy ion acoustic waves(HIAWs) of multi-ion plasma are studied. The plasma consists of adiabatic positively charged inertial heavy ions, Boltzmann energy distributed light ions and kappa energy distributed electrons. The extended poincaré-Lighthill-Kuo(e PLK) method is applied for the derivation of two-sided Korteweg–de Vries(KdV) equations(KdVEs). The KdV single-soliton solutions(KdVSSs) are determined using the hyperbolic secant method and the KdV multi-soliton solutions(KdVMSs)are obtained using the Hirota method. The effects of superthermality of electrons, temperature ratios of electron to light ion and heavy ion to electron, and the density ratio of electron to heavy ion on phase shifts are investigated for the head-on collisions between two-soliton HIAWs. The effects of plasma parameters on angular frequency, phase speed, production of multi-soliton structures, and the head-on collisions among single-, double-, triple-, quadruple-, and quintuplesolitons are also studied.
基金National Natural Science Foundation of China under Grant Nos.60678022 and 10704001the Specialized Research Fund for the Doctoral Program of Higher Education of Anhui Province under Grant No.20060357008+2 种基金Natural Science Foundation of Anhui Province under Grant No.070412060the Talent Foundation of Anhui UniversityAnhui Key Laboratory of Information Materials and Devices (Anhui University)
文摘We propose a scheme for generating multi-ion graph states using many trapped ions in thermal motion.Our generation scheme is insensitive to external state since the interaction between ions and laser fields does not involvethe external degree of freedom.The scheme can be well realized within the current experimental technique.
文摘The nonlinear propagation of the DIA (dust ion-acoustic) waves in multi-ion dense plasma system containing degener- ate electrons, both positive and negative ions, arbitrary charged dust grains has been investigated by employing the reductive perturbation method. The nonlinear waves (solitary and shock waves) have been observed to be formed in case of both positive and negative charged dust grains from the stationary solution of the Korteweg de-Vries (K-dV) equation and Burger’s equation. The fundamental properties of such nonlinear waves have been theoretically analyzed by comparing system potential for both positive and negative dust grains. It has been shown that the basic features of these waves are significantly modified by the positive and negative ions drift speed and polarities of dust grains. The implications of our results in space and laboratory plasmas are briefly discussed.
文摘利用多组态Dirac-Hartree-Fock方法对类碳等电子序列(Z=10,14,32,36,50)1s^(2)2s^(2)2p^(2)和1s^(2)2s2p^(3)组态的能级结构和电偶极跃迁行为进行理论研究.在构建充分包含电子关联效应、规模适当的波函数后,考虑Breit相互作用、量子电动力学效应和原子核质量效应,比较分析了价-价关联效应、实-价关联效应和实-实关联效应对原子态激发能的影响,完成了原子态激发能的高精度理论计算.与其他理论结果相比,本文计算的Ne V离子的激发能结果与NIST(National Institute of Standards and Technology)数据最为接近;其他离子的激发能也具有较好的精度.在此基础上,结合LS耦合的原子态混合成分和NIST数据,对出现的原子态命名情况进行分析,推测了相应的原子态命名.本文还计算了组态间电偶极跃迁的谱线波长、跃迁速率、线强和加权振子强度,Ne V和Si IX离子的谱线波长与NIST数据符合得很好,相对误差小于0.62%;跃迁速率与其他理论结果比较一致.另外,本文计算得到的Babushkin和Coulomb两种规范的电偶极跃迁参数具有良好的一致性,进一步证明了本文采用的理论方法的准确性和可靠性.
