As cathode materials for alkali-ion batteries,sodium manganese oxides have been receiving considerable and continuous attention in recent decades.In this work,the structure and environment-dependent stability of NaMn_...As cathode materials for alkali-ion batteries,sodium manganese oxides have been receiving considerable and continuous attention in recent decades.In this work,the structure and environment-dependent stability of NaMn_(2)O_(4) surface were studied based on the first principles calculations.The surface stability diagram of NaMn_(2)O_(4) involving various different terminations of(100),(110)and(111)surfaces was constructed,and the stability of these different terminations could be compared as a function of chemical environment.It is found that the(100)-MnO and(111)-ONa terminations are two more stable terminations under the investigated chemical conditions.And the surface energies of(110)surfaces are negative under the investigated chemical potential,hence,(110)surfaces are unstable.The surface energy of NaMn_(2)O_(4) as a function of O chemical potential is also investigated under constant Na chemical potential.The structure relaxation indicates that the surface rumpling and surface reconstruction can affect the electronic structure of the surface,thereby reducing surface energy and stabilizing the surface.Furthermore,the Wulff shape of NaMn_(2)O_(4) was also constructed based on Gibbs-Wulff theorem.展开更多
Command, control, communication, computing, intel- ligence, surveillance and reconnaissance （C^4ISR） in information age is a complex system whose structure always changes ac- tively or passively during the warfare. ...Command, control, communication, computing, intel- ligence, surveillance and reconnaissance （C^4ISR） in information age is a complex system whose structure always changes ac- tively or passively during the warfare. Therefore, it is important to optimize the structure, especially in ambiguous and quick-tempo modern warfare. This paper proposes an adaptive evolvement mechanism for the C^4ISR structure to survive the changeable warfare. Firstly, the information age C^4ISR structure is defined and modeled based on the complex network theory. Secondly, taking the observe, orient, decide and act （OODA） model into consideration, four kinds of loops in the C^4ISR structure are pro- posed and their coefficient of networked effects （CNE） is further defined. Then, the adaptive evolvement mechanisms of the four kinds of loops are presented respectively. Finally, taking the joint air-defense C^4ISR as an example, simulation experiments are im- plemented, which validate the evolvement mechanism and show that the information age C41SR structure has some characteristics of small-world network and scale-free network.展开更多
基金Project(BK20241969)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(51971249)supported by the National Natural Science Foundation of China。
文摘As cathode materials for alkali-ion batteries,sodium manganese oxides have been receiving considerable and continuous attention in recent decades.In this work,the structure and environment-dependent stability of NaMn_(2)O_(4) surface were studied based on the first principles calculations.The surface stability diagram of NaMn_(2)O_(4) involving various different terminations of(100),(110)and(111)surfaces was constructed,and the stability of these different terminations could be compared as a function of chemical environment.It is found that the(100)-MnO and(111)-ONa terminations are two more stable terminations under the investigated chemical conditions.And the surface energies of(110)surfaces are negative under the investigated chemical potential,hence,(110)surfaces are unstable.The surface energy of NaMn_(2)O_(4) as a function of O chemical potential is also investigated under constant Na chemical potential.The structure relaxation indicates that the surface rumpling and surface reconstruction can affect the electronic structure of the surface,thereby reducing surface energy and stabilizing the surface.Furthermore,the Wulff shape of NaMn_(2)O_(4) was also constructed based on Gibbs-Wulff theorem.
基金supported by the National Defense Basic Research Program of China and National Defense Pre-Research Foundation of China
文摘Command, control, communication, computing, intel- ligence, surveillance and reconnaissance （C^4ISR） in information age is a complex system whose structure always changes ac- tively or passively during the warfare. Therefore, it is important to optimize the structure, especially in ambiguous and quick-tempo modern warfare. This paper proposes an adaptive evolvement mechanism for the C^4ISR structure to survive the changeable warfare. Firstly, the information age C^4ISR structure is defined and modeled based on the complex network theory. Secondly, taking the observe, orient, decide and act （OODA） model into consideration, four kinds of loops in the C^4ISR structure are pro- posed and their coefficient of networked effects （CNE） is further defined. Then, the adaptive evolvement mechanisms of the four kinds of loops are presented respectively. Finally, taking the joint air-defense C^4ISR as an example, simulation experiments are im- plemented, which validate the evolvement mechanism and show that the information age C41SR structure has some characteristics of small-world network and scale-free network.
