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Rational design of porous carbon allotropes as anchoring materials for lithium sulfur batteries

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Journal of Energy Chemistry 2021年第1期30卷 121-129,I0005页

作者： Tongtong Li cheng he Wenxue Zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina School of Materials Science and Engineering Chang’an UniversityXi’an 710064ShaanxiChina

The shuttle effect seriously impedes the development and practical application of lithium sulfur(Li-S)*** is still a long-term challenge to find effective anchoring materials to hinder the shuttle effect of Li-S *** carbon allotrope as anchoring materials is an effective strategy to alleviate the shuttling ***,the influence factors of carbon allotrope on the adsorption performance of LIPSS at the atomic level are not clear,which limits the application of carbon allotrope in Li-S ***,using first-principles simulations,a systematical calculation of carbon allotropes with various ring size(6 ≤S≤16) and shape is conducted to understand the adsorption *** results show that the T-G monolayers with suitable ring structure and high charge transfer can significantly enhance the interaction between the monolayer and LiPSs,allowing them to have high capacity and high coulombic *** diffusion studies show that LiPSs on the T-G monolayer have the low diffusion barriers,which ensures the charging and discharging rate of *** studies could provide material design principles of carbon allotrope monolayers used as anchoring materials of the high performance Li-S batteries.

关键词： Lithium-sulfur battery Anchoring material Shuttle effect Density functional theory

Building up a general selection strategy and catalytic performance prediction expressions of heteronuclear double-atom catalysts for N_(2)reduction

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Journal of Energy Chemistry 2023年第7期82卷 375-386,I0009页

作者： Yibo Wu cheng he Wenxue Zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi'an Jiaotong UniversityXi'an 710049ShannxiChina School of Materials Science and Engineering Chang'an UniversityXi'an 710064ShannxiChina

The severe environmental problems and the demand for energy urgently require electrocatalysis to replace Haber-Bosch for the nitrogen reduction reaction(NRR).The descriptors and important properties of single-atom and homonuclear double-atom catalysts have been preliminarily explored,but the relationship between the inherent properties and catalytic activity of heteronuclear double-atom catalysts with better performance remains ***,it is very significant to explore the prediction expressions of catalytic activity of heteronuclear double-atom catalysts based on their inherent properties and find the rule for selecting catalytic ***,by summarizing the free energy for the key steps of NRR on 55 catalysts calculated through the first-principle,the expressions of predicting the free energy and the corresponding descriptors are deduced by the machine learning,and the strategy for selecting the appropriate catalytic center is *** selection strategy for the central atom of heteronuclear double-atom catalysts is that the atomic number of central B atom should be between group VB and VIIIB,and the electron difference between central A atom and B atom should be large enough,and the selectivity of NRR or hydrogen evolution reaction(heR)could be calculated through the prediction ***,five catalysts are screened to have low limiting potential and excellent selectivity,and are further analyzed by electron *** work explores the relationship between the inherent properties of heteronuclear double-atom catalysts and the catalytic activity,and puts forward the rules for selecting the heteronuclear double-atom catalytic center,which has guiding significance for the experiment.

关键词： heteronuclear double-atom catalyst Nitrogen reduction reaction Density functional theory Prediction expression Selection strategy

The Minimum Centroid Branch Spanning Tree Problem

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Journal of the Operations Research Society of China 2024年第2期12卷 528-539页

作者： Hao Lin cheng he School of Science Henan University of TechnologyZhengzhou450001HenanChina

For a spanning tree T of graph G,the centroid of T is a vertex v for which the largest component of T-v has as few vertices as *** number of vertices of this component is called the centroid branch weight of *** minimum centroid branch spanning tree problem is to find a spanning tree T of G such that the centroid branch weight is *** application to design of communication networks,the loads of all branches leading from the switch center should be as balanced as *** this paper,we prove that the problem is strongly NP-hard even for bipartite ***,the problem is shown to be polynomially solvable for split graphs,and exact formulae for special graph familis,say Kn_(1),n_(2),...,n_(k)and P_(m)×P_(n),are presented.

关键词： Spanning tree optimization Centroid branch-NP-hardness Polynomial-time algorithm

Dwell scheduling algorithm for multifunction phased array radars based on the scheduling gain

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Journal of Systems Engineering and Electronics 2008年第3期19卷 479-485页

作者： cheng Ting he Zishu Tang Ting School of Electronic Engineering Univ. of Electronic Science and Technology Chengdu 610054 P. R. China

A real-time dwell scheduling model, which takes the time and energy constraints into account is founded from the viewpoint of scheduling gain. Scheduling design is turned into a nonlinear programming procedure. The real-time dwell scheduling algorithm based on the scheduling gain is presented with the help of two heuristic rules. The simulation results demonstrate that compared with the conventional adaptive scheduling method, the algorithm proposed not only increases the scheduling gain and the time utility but also decreases the task drop rate.

关键词： multifunction phased array radar dwell scheduling pulse interleaving time and energy constraint.

Novel radar dwell scheduling algorithm based on pulse interleaving

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Journal of Systems Engineering and Electronics 2009年第2期20卷 247-253页

作者： cheng Ting he Zishu Tang Ting School of Electronic Engineering Univ. of Electronic Science and Technology Chengdu 610054 P. R. China

The problem of scheduling radar dwells in multifunction phased array radar systems is addressed. A novel dwell scheduling algorithm is proposed. The whole scheduling process is based on an online pulse interleaving technique. It takes the system timing and energy constraints into account. In order to adapt the dynamic task load, the algorithm considers both the priorities and deadlines of tasks. The simulation results demonstrate that compared with the conventional adaptive dwell scheduling algorithm, the proposed one can improve the task drop rate and system resource utility effectively.

关键词： dwell scheduling pulse interleaving energy constraint priority deadline

“Capture-activation-recapture” mechanism-guided design of double-atom catalysts for electrocatalytic nitrogen reduction

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Journal of Energy Chemistry 2024年第9期96卷 437-447页

作者： cheng he Shiqi Yan Wenxue Zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina School of Materials Science and Engineering Chang’an UniversityXi’an 710064ShaanxiChina

Compared with the traditional industrial nitrogen fixation, electrocatalytic methods, especially those utilizing double-atom catalysts containing nonmetals, can give good consideration to the economy and environmental protection. However, the existing “acceptance-donation” mechanism is only applicable to bimetallic catalysts and nonmetallic double-atom catalysts containing boron atoms. herein, a novel “capture-activation-recapture” mechanism for metal-nonmetal double-atom catalyst is proposed to solve the problem by adjusting the coordination environments of nonmetallic atoms and utilizing the activation effect of metal atoms on nitrogen. Based on this mechanism, the nitrogen reduction reaction (NRR) activity of 48 structures is calculated by density functional theory calculation, and four candidates are selected as outstanding electrocatalytic nitrogen reduction catalysts: Si-Fe@NG (U_(L) = –0.14 V), Si-Co@NG (U_(L)= –0.15 V), Si-Mo@BP1 (U_(L) = 0 V), and Si-Re@BP1 (U_(L) = –0.02 V). The analyses of electronic properties further confirm “capture-activation-recapture” mechanism and suggest that the difference in valence electron distribution between metal and Si atoms triggers the activation of N≡N bonds. In addition, a machine learning approach is utilized to generate an expression and an intrinsic descriptor that considers the coordination environment to predict the limiting potential. This study offers profound insight into the synergistic mechanism of TM and Si for NRR and guidance in the design of novel double-atom nitrogen fixation catalysts.

关键词： "Capture-activation-recapture"mechanism Double-atom catalyst Nitrogen reduction reaction Density functional theory

On Fixed-Parameter Solvability of the Minimax Path Location Problem

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Communications on Applied Mathematics and Computation 2023年第4期5卷 1644-1654页

作者： Hao Lin cheng he School of Science Henan University of TechnologyZhengzhou450001HenanChina

The minimax path location problem is to find a path P in a graph G such that the maximum distance d_(G)(v,P)from every vertex v∈V(G)to the path P is *** is a well-known NP-hard problem in network *** paper studies the fixed-parameter solvability,that is,for a given graph G and an integer k,to decide whether there exists a path P in G such that max v∈V(G)d_(G)(v,P)≤*** the answer is affirmative,then graph G is called *** show that this decision problem is NP-complete even for k=*** the other hand,we characterize the family of 1-path-eccentric graphs,including the traceable,interval,split,permutation graphs and ***,some polynomially solvable special graphs are discussed.

关键词： Discrete location Path location Fixed-parameter solvability Graph characterization Polynomial-time algorithm

A hierarchical updating method for finite element model of airbag buffer system under landing impact

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Chinese Journal of Aeronautics 2015年第6期28卷 1629-1639页

作者： he Huan Chen Zhe he cheng Ni Lei Chen Guoping State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Institute of Vibration Engineering Research Nanjing University of Aeronautics and Astronautics Research Institute of Pilotless Aircraft Nanjing University of Aeronautics and Astronautics China Aviation Industry General Aircraft Co.Ltd.

In this paper, we propose an impact finite element （FE） model for an airbag landing buf- fer system. First, an impact FE model has been formulated for a typical airbag landing buffer system. We use the independence of the structure FE model from the full impact FE model to develop a hierarchical updating scheme for the recovery module FE model and the airbag system FE model. Second, we define impact responses at key points to compare the computational and experimental results to resolve the inconsistency between the experimental data sampling frequency and experi- mental triggering. To determine the typical characteristics of the impact dynamics response of the airbag landing buffer system, we present the impact response confidence factors （IRCFs） to evalu- ate how consistent the computational and experiment results are. An error function is defined between the experimental and computational results at key points of the impact response （KPIR） to serve as a modified objective function. A radial basis function （RBF） is introduced to construct updating variables for a surrogate model for updating the objective function, thereby converting the FE model updating problem to a soluble optimization problem. Finally, the developed method has been validated using an experimental and computational study on the impact dynamics of a classic airbag landing buffer system.

关键词： Airbag Hierarchical model Impact Model updating Radial basis function

The InSe/g-CN van der Waals hybrid heterojunction as a photocatalyst for water splitting driven by visible light

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Chinese Chemical Letters 2022年第1期33卷 404-409页

作者： cheng he Fusheng Han Wenxue Zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi'an Jiaotong UniversityXi'an 710049China. School of Materials Science and Engineering Chang'an UniversityXi'an 710064China

Designing and developing the highly efficient photocatalysts is full of significance to achieve spontaneous photolysis *** this work,using the first-principles calculations,we have performed a systematic theoretical study of water splitting photocatalytic activity of the InS e/g-CN *** is concluded that the In Se/g-CN heterojunction is a typical type-II semiconductor,whose electrons and holes can be effectively *** the potential of the conduction band minimum(CBM)and valence band maximum(VBM)satisfy the requirements for photolysis ***,the changes of Gibbs free energy(ΔG)of the oxygen evolution reaction(OER)and the hydrogen evolution reaction(heR)are calculated to investigate thermodynamic sustainability of photolysis *** results show that when pH=7,the potential driving force provided by the InSe/g-CN heterojunction can ensure the spontaneous progress of heR and *** addition,it is found that the solar conversion efficiency(η;)of the In Se/g-CN heterojunction is up to 13.7%,which indicates it has broad commercial application ***,the In Se/g-CN heterojunction is expected to be an excellent candidate for photolysis water.

关键词： Photolysis water First-principles Type-Ⅱsemiconductor Solar-to-hydrogen