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Applied Mathematics and Mechanics(English Edition) 2018年第7期39卷 1031-1044页

作者： Si yuan Yue WU Qinyan xing Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil Engineering Tsinghua University

This paper presents a strategy for computation of super-convergent solutions of multi-dimensional problems in the finite element method （FEM） by recursive application of the one-dimensional （1D） element energy projection （EEP） technique. The main idea is to conceptually treat multi-dimensional problems as generalized 1D problems, based on which the concepts of generalized 1D FEM and its consequent EEP formulae have been developed in a unified manner. Equipped with these concepts, multi-dimensional problems can be recursively discretized in one dimension at each step, until a fully discretized standard finite element （FE） model is reached. This conceptual dimension-by- dimension （D-by-D） discretization procedure is entirely equivalent to a full FE discretization. As a reverse D-by-D recovery procedure, by using the unified EEP formulae together with proper extraction of the generalized nodal solutions, super-convergent displacements and first derivatives for two-dimensional （2D） and three-dimensional （3D） problems can be obtained over the domain. Numerical examples of 3D Poisson＇s equation and elasticity problem are given to verify the feasibility and effectiveness of the proposed strategy.

关键词： three-dimensional(3D)problem generalized one-dimensional(1D)finiteelement method (FEM) dimension-by-dimension(D-by-D) super-convergence elementenergy projection(EEP)

Development of an improved CBR model for predicting steel temperature in ladle furnace refining

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International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1321-1331页

作者： Fei yuan An-jun Xu Mao-qiang gu School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In the prediction of the end-point molten steel temperature of the ladle furnace, the influence of some factors is nonlinear. The prediction accuracy will be affected by directly inputting these nonlinear factors into the data-driven model. To solve this problem, an improved case-based reasoning model based on heat transfer calculation(CBR-HTC) was established through the nonlinear processing of these factors with software Ansys. The results showed that the CBR-HTC model improves the prediction accuracy of end-point molten steel temperature by5.33% and 7.00% compared with the original CBR model and 6.66% and 5.33% compared with the back propagation neural network(BPNN)model in the ranges of [-3, 3] and [-7, 7], respectively. It was found that the mean absolute error(MAE) and root-mean-square error(RMSE)values of the CBR-HTC model are also lower. It was verified that the prediction accuracy of the data-driven model can be improved by combining the mechanism model with the data-driven model.

关键词： case-based reasoning LF refining steel temperature prediction ladle lining

From atom to monatomic wire:an ab initio study of magnetism in 3d transition metals

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Acta Metallurgica Sinica(English Letters) 2010年第3期23卷 191-196页

作者： Zhili ZHU Jinhua gu Yu JIA xing HU School of Physical Engineering and Material Physics Laboratory Zheng Zhou University Zhengzhou 450052 China

A systematic ab initio study on magnetism of the 3d transition metals（TM） from atom to monoatomic wire within density functional theory with generalized gradient approximation（GGA） was *** results show that the spin coupling has strong intraatomic exchange strengths about 1 eV for isolated 3d TM *** magnetic moments are distinctly lower than those of free atoms for all dimers except Mn 2 .All the 3d TM elements exhibit magnetic ground states in the linear wire structure.

关键词： Ab initio study Magnetism Transition metals

Superconducting Single-Layer T-Graphene and Novel Synthesis Routes

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Chinese Physics Letters 2019年第9期36卷 46-63页

作者： Qinyan gu Dingyu xing Jian Sun National Laboratory of Solid State Microstructures School of Physics and Collaborative Innovation Center of Ad vanced MicrostructuresNanjing UniversityNanjing 210093

Single-layer superconductors are ideal materials for fabricating superconducting nano ***,up to date,very few single-layer elemental superconductors have been predicted and especially no one has been successfully synthesized ***,using crystal structure search techniques and ab initio calculations,we predict that a single-layer planar carbon sheet with 4-and 8-membered rings called T-graphene is a new intrinsic elemental superconductor with superconducting critical temperature(Tc)up to around 20.8 *** importantly,we propose a synthesis route to obtain such a single-layer T-graphene,that is,a T-graphene potassium intercalation compound(C4 K with P4/mmm symmetry)is firstly synthesized at high pressure(>11.5 GPa)and then quenched to ambient condition;and finally,the single-layer T-graphene can be either exfoliated using the electrochemical method from the bulk C4 K,or peeled off from bulk T-graphite C4,where C4 can be obtained from C4 K by evaporating the K ***,we find that the calculated Tc of C4 K is about 30.4 K at 0 GPa,which sets a new record for layered carbon-based *** present findings add a new class of carbon-based *** particular,once the single-layer T-graphene is synthesized,it can pave the way for fabricating superconducting devices together with other 2 D materials using the layer-by-layer growth techniques.

关键词： red Superconducting Single-Layer T-Graphene and Novel Synthesis Routes Graphene

Synthesis of a Novel Conjugate of Bromoarene and Polyamide Containing N-Methylimidazoles

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Chinese Chemical Letters 2005年第10期16卷 1330-1332页

作者： Dan LIU gu yuan Department of Chemical Biology The Key Laboratory of Bioorganic Chemistry and MolecularEngineering of Ministry of Education College of Chemistry Peking University Beijing 100871

A novel DNA cleavage conjugate of bromoarene and polyamide containing three N-methylimidazole rings was synthesized by the chloroform reaction and the DCC/HOBT coupling reaction.

关键词： DNA cleavage bromoarene polyamide chloroform reaction.

Theoretical analysis of optical force density distribution inside subwavelength-diameter optical fibers

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Chinese Physics B 2018年第10期27卷 362-367页

作者： Yun-yuan Zhang Hua-Kang Yu Xiang-Ke Wang Wan-Ling Wu Fu-xing gu Zhi-yuan Li School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510641China Shanghai Key Laboratory of Modern Optical System Engineering Research Center of Optical Instrument and System（Ministry of Education）University of Shanghai for Science and TechnologyShanghai 200093China

We investigate the microscopic optical force density distributions respectively inside a subwavelength-diameter（SD）fiber with flat endface and inside one with oblique endface by using a finite-difference time-domain（FDTD） *** force density distributions at the fiber endfaces can now be readily available. The complete knowledge of optical force density distributions not only reveal features regarding the microscopic near-field optomechanical interaction, but also provide straightforward explanations for the sideway deflections and other mechanical motions. Our results can provide a useful reference for better understanding the mechanical influence when light transports in a microscale or nanoscale structure and for developing future highly-sensitive optomechanical devices.

关键词： subwavelength-diameter optical fibers optical force

Optimal Initialization and Starting Approach of Synchronous Condenser Integrated Power Grid

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 248-260页

作者： Puyu Wang xing Liu Qingwen Mou Tao yuan Tianming gu Hemin Yang Xiao-Ping Zhang Zhengrong Xiang Chunyi guo School of Automation Nanjing University of Science and TechnologyNanjing 210094China NARI Group Corporation/State Grid EPRI and also with NARI Technology Co.Ltd. Nanjing 211106China School of Engineering University of BirminghamBirminghamB152TTUnited Kingdom State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

Synchronous condensers(SCs)are generally used at the receiving-end stations of ultra-high-voltage direct current(UHVDC)transmission systems due to their strong reactive power support and flexible regulation of reactive power according to the interconnected grids operating *** this paper,different starting control schemes of a SC integrated power grid are investigated providing four main contributions:1)The principle of reactive power support of the SC on the interconnected power grid is analytically studied,providing the establishment of mathematical models.2)Four different starting control schemes are developed for the initialization and SC integration,*** Scheme 1,a preset initial falling speed is directly utilized without initialization;in Scheme 2,a black start sequential control approach with a static frequency converter(SFC)is proposed;in Scheme 3,PI/PD/PID controllers are respectively applied for the excitation device at the speed-falling stage;in Scheme 4,a pre-insertion approach of an energy absorption component with R/L/RL is utilized to suppress the surges at the SC integration instant.3)The dynamic behaviors of four different starting schemes at specific operating stages are evaluated.4)The success rate of SC integration is analyzed to evaluate starting control *** of the SC interconnected system with four different starting control schemes is evaluated in the timedomain simulation environment PSCAD/EMTDC^(TM).The results prove the superiority of the proposed starting control approach in Scheme 4.

关键词： Black start dynamic behaviors excitation system pre-insertion of energy absorption components starting control schemes static frequency converter(SFC) success rate of integration synchronous condenser(SC)

Insight into Lithium–sulfur batteries performance enhancement:from metal nanoparticles to metal nanoclusters to single metal atoms

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Tungsten 2024年第3期6卷 504-521页

作者： Shuang Ma Qing-Ling Ruan Xue-Cheng Liu gui-Jun Zhu Die yuan Ling-Qiao Hu Yu-Mei Huang xing-xing gu Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and ResourcesChongqing Technology and Business UniversityChongqing 400067China National Research Base of Intelligent Manufacturing Service Chongqing Technology and Business UniversityChongqing 400067China

Lithium-sulfur(Li-S)batteries have attracted much attention and developed rapidly in recent years due to their high energy density,low cost,and ***,its commercialization process still encounters various *** them,the sulfur cathode is easy to dissolve and shuttle,resulting in the loss of active substances and the severe growth of lithium anode dendrites,which is one of the biggest *** the redox conversion kinetics of sulfur cathode is expected to fundamentally alleviate the shuttle phenomenon of poly ***,this paper reviews the effects of metal nanoparticles to metal nanoclusters to metal single-atom catalysts on improving the redox of Li-S batteries,to let researchers better understand the size effect on the kinetics of sulfur cathodes in Li-S batteries,which will provide important guidance for the future large-scale commercialization of Li-S batteries.

关键词： Lithium–sulfur batteries Metal nanoparticles Metal nanoclusters Metal single atoms Size effects

Synergistic effect of size-dependent PtZn nanoparticles and zinc single-atom sites for electrochemical ozone production in neutral media

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Journal of Energy Chemistry 2020年第12期29卷 312-322页

作者： Bowen yuan Zihao Yao Chenlong Qiu Haiyang Zheng Yilong Yan Qiaoqiao Zhang Xiang Sun Yu gu xing Zhong Jianguo Wang Institute of Industrial Catalysis State Key Laboratory Breeding Base of Green-Chemical Synthesis TechnologyCollege of Chemical EngineeringZhejiang University of TechnologyHangzhou 310032ZhejiangChina

Electrochemical ozone production(EOP) via water electrolysis represents an attractive method for the generation of high-purity O3. Herein, the X-PtZn/Zn-N-C electrocatalysts show a strong structural sensitive behavior depends on the size of the PtZn nanoparticles and their EOP activity exhibits a volcano-type dependence for the O3 performance in neutral media. The 7.7-PtZn/Zn-N-C exhibits EOP current efficiency of 4.2%, and shows the prominent performance in the production of gaseous O3 with a value of 1647 ppb at 30 min, which is almost 4-fold compared to 2.2-Pt Zn/Zn-N-C. Based on the experiments and theoretical calculations, the performance of the EOP process was determined by the nanoparticle size-effect and the synergistic effect between the PtZn nanoparticles and atomically dispersed Zn-N-C. Furthermore, the fivemembered cyclic structure of O3 can be stabilized between the PtZn nanoparticle and the Zn-N-C support,indicating that O3 is produced at the interface.

关键词： Electrochemical ozone production PtZn Single-atom catalysts Size effect Synergistic effect

Computational pharmacological studies on cardiovascular disease by Qishen Yiqi Diwan

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Science China Chemistry 2009年第11期52卷 1871-1878页

作者： gu JiangYong yuan gu ZHU YongHong XU XiaoJie Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Academy of Tasly Pharmaceutical Co. LTDTianjin 300410China

Computational pharmacological methods were used to study the distribution of 1729 compounds contained in a Chinese medicine,Qishen Yiqi Diwan,in chemical *** results show that most of these compounds have good drug-like *** docking was used to study the interactions between 1729 compounds of Qishen Yiqi Diwan and 26 drug targets related to cardiovascular disease and the distribution of 1729 compounds in drug-target *** results may shed light on the action mechanism and the search for the active compounds in Qishen Yiqi Diwan.

关键词： chemical space drug-target space molecular docking computational pharmacology