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Universal design of three-dimensional porous graphene-iron based promotors for kinetically rationalized lithium-sulfur chemistry

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Journal of Energy Chemistry 2025年第1期100卷 192-200页

作者： hua gao Yunfeng Zhang Menglei Wang Ruoxuan Yang Shuai Feng Xuan Cao Yaping Zhang Zhongyuan Lu Yingze Song State Key Laboratory of Environment-Friendly Energy Materials School of Materials and Chemistry Southwest University of Science and Technology School of Material Science and Engineering Henan University of Technology College of Chemistry and Chemical Engineering Taishan University

Lithium-sulfur （Li-S） batteries are widely deemed to be one of the most potential candidates for future secondary batteries because of their remarkable energy ***,notorious polysulfide shuttling and retarded sulfur reaction kinetics pose significant obstacles to the further application of Li-S *** rationally designed highly active electrocatalysts can facilitate polysulfide conversion,the universal and scalable synthesis strategies need to be ***,a universal synthetic strategy to construct a series of three-dimensional （3D） porous graphene-iron （3DGr-Fe） based electrocatalysts involving 3DGr-FeP,3DGr-Fe3C,and 3DGr-Fe3Se4is exploited for manipulating the Li-S redox *** has been observed that the implementation of a 3D porous Gr architecture leads to the well-designed conductive networks,while the uniformly dispersed iron nanoparticles introduce an abundance of active sites,fostering the lithium polysulfide conversion,thereby bolstering the overall electrochemical *** Li-S battery with the 3DGr-Fe based electrocatalyst exhibits remarkable capacity retention of 94.8%upon 100 times at 0.2 ***,the soft-packaged Li-S pouch cell based on such a 3DGr-Fe electrocatalyst delivers superior capacity of 1060.71 mA h g-1and guarantees for the continuous 30 min work of fan *** investigation gives comprehensive insights into the design,synthesis,and mechanism of 3DGr-Fe based electrocatalysts with high activity toward efficient and durable Li-S batteries.

关键词： Redox reactions

Membership determination of open cluster NGC 188 based on the DBSCAN clustering algorithm

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Research in Astronomy and Astrophysics 2014年第2期14卷 159-164页

作者： Xin-hua gao School of Information Science and Engineering Changzhou University

High-precision proper motions and radial velocities of 1046 stars are used to determine member stars using three-dimensional （3D） kinematics for open clus- ter NGC 188 based on the density-based spatial clustering of applications with noise （DBSCAN） clustering algorithm. By implementing this algorithm, 472 member stars in the cluster are obtained with 3D kinematics. The color-magnitude diagram （CMD） of the 472 member stars using 3D kinematics shows a well-defined main sequence and a red giant branch, which indicate that the DBSCAN clustering algorithm is very effective for membership determination. The DBSCAN clustering algorithm can ef- fectively select probable member stars in 3D kinematic space without any assumption about the distribution of the cluster or field stars. Analysis results show that the CMD of member stars is significantly clearer than the one based on 2D kinematics, which al- lows us to better constrain the cluster members and estimate their physical parameters. Using the 472 member stars, the average absolute proper motion and radial velocity are determined to be （PMα, PMδ） = （-2.58 ± 0.22, ＋0.17 ± 0.18） mas yr-1 and Vr = -42.35 ± 0.05 km s-1, respectively. Our values are in good agreement with values derived by other authors.

关键词： Galaxy: open clusters and associations: individual (NGC 188) -- stars:kinematics -- Hertzsprung-Russell diagram -- techniques: radial velocities

An application of the KNND method for detecting nearby open clusters based on Gaia-DR1

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Research in Astronomy and Astrophysics 2017年第6期17卷 89-94页

作者： Xin-hua gao School of Information Science and Engineering Changzhou University Changzhou 213164 China

This paper presents a preliminary test of the k-th nearest neighbor distance （KNND） method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars （〈 100 pc） from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions （the Hyades and Coma Berenices （Coma Ber） open clusters）, and obtain 57 reliable cluster members. Based on these cluster members, the distances to the Hyades and Coma Ber clusters are determined to be 46.0±0.2 and 83.5±0.3 pc, respectively. Our results demonstrate that the KNND method can be used to detect open clusters based on a large volume of astrometry data.

关键词： open clusters and associations individual (Hyades, Coma Ber) - astrometry- parallaxes- stars distances

An application of the k-th nearest neighbor method to open cluster membership determination

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Research in Astronomy and Astrophysics 2016年第12期16卷 46-50页

作者： Xin-hua gao School of Information Science and Engineering Changzhou University

We introduce a non-parametric method for open cluster membership determination in threedimensional（3D） velocity space（proper motion and radial velocity）. Clean 3D cluster members can be obtained by statistically analyzing the Euclidean distance between each star and its k-th nearest neighbor in3 D velocity space. We use 513 sample stars in the direction of open cluster M67 to construct a 3D velocity space and test our method; 291 3D cluster members are obtained. The color-magnitude diagram, proper motions, radial velocities and spatial distribution of these 3D cluster members demonstrate the effectiveness of our method. From the 291 3D cluster members, the mean radial velocity and absolute proper motion of M67 are Vr = ＋33.46 ± 0.05 km s-1and（PMRA, PMDEC） =（-7.64 ± 0.07,-5.98 ± 0.07） mas yr-1,respectively. In addition, we use 640 sample stars with precise proper motions and radial velocities in the direction of open cluster NGC 188 to test our method. The test results also show that our method is effective.

关键词： open clusters and associations: individual (M67)-- Hertzsprung-Russell and C-M diagrams--stars: kinematics and dynamics

MODIFIED BERNOULLI ITERATION METHODS FOR QUADRATIC MATRIX EQUATION

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Journal of Computational Mathematics 2007年第5期25卷 498-511页

作者： Zhong-Zhi Bai Yong-hua gao LSEC ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China

We construct a modified Bernoulli iteration method for solving the quadratic matrix equation AX^2 ＋ BX ＋ C = 0, where A, B and C are square matrices. This method is motivated from the Gauss-Seidel iteration for solving linear systems and the ShermanMorrison-Woodbury formula for updating matrices. Under suitable conditions, we prove the local linear convergence of the new method. An algorithm is presented to find the solution of the quadratic matrix equation and some numerical results are given to show the feasibility and the effectiveness of the algorithm. In addition, we also describe and analyze the block version of the modified Bernoulli iteration method.

关键词： Quadratic matrix equation Quadratic eigenvalue problem Solvent Bernoulli's iteration Newton's method Local convergence.

Kinematic and chemical properties of five open clusters based on SDSS DR7

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Research in Astronomy and Astrophysics 2010年第8期10卷 761-776页

作者： Xin-hua gao Li Chen Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory for Astrophysics Shanghai 200234 China

We present metallicities and radial velocities for five old open clusters （NGC 6791, NGC 2420, NGC 2682, NGC 2158, and NGC 7789） using data from the seventh public data release of the Sloan Digital Sky Survey （SDSS）, which includes the directed stellar program SEGUE： Sloan Extension For Galactic Understanding and Exploration. The radial velocities are used to calculate cluster membership probabilities for stars in each cluster region. NGC 6791, NGC 2420, NGC 2682, NGC 2158 and NGC 7789 are found to have mean metallicities [Fe/H]= ＋0.08 ± 0.09, -0.38± 0.11, -0.08±0.05, -0.41 ±0.13 and -0.19 ± 0.13 dex （s.d.）, respectively. The mean radial velocities for NGC 6791, NGC 2420, NGC 2682, NGC 2158 and NGC 7789 are Vr = -45.9 ± 0.2, ＋76.1 ± 0.2, ＋35.0 ± 0.2, ＋26.9 ± 0.2 and -48.2± 0.2 km s^-1（s.e.m.）, respectively. We have compared our results with the values from literatures, and found that our metallicity of NGC 6791 is significantly underestimated （by about 0.3 dex） and our radial velocities of the open clusters agree well with the values derived using high-resolution spectroscopy.

关键词： open clusters and associations general -- open clusters and associations individual (NGC 6791, NGC 2420, NGC 2682, NGC 2158, NGC 7789)

Attractive natural products with strained cyclopropane and/or cyclobutane ring systems

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Science China Chemistry 2016年第9期59卷 1126-1141页

作者： Yao-Yue Fan Xin-hua gao Jian-Min Yue Shanghai Institute of Materia Medica Chinese Academy of Sciences

The strained cyclopropane and/or cyclobutane subunits occurred in many complex natural products including terpenoids, steroids and alkaloids. Natural products with cyclopropane and/or cyclobutane motifs not only furnished fascinating structures, but also exhibited versatile biological activities, such as cytotoxic, anti-HIM antimicrobial, antiviral, and immunosuppressive effects. This review covered a large array of structurally unique natural products with strained cyclopropane and/or cyclobutane motifs and summarized their structural features, distributions, biological activities, as well as biogenetic considerations.

关键词： natural products cyclopropane-containing cyclobutane-containing biological activity biosynthetic pathway

Snapping instability in prismatic tensegrities under torsion

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Applied Mathematics and Mechanics(English Edition) 2016年第3期37卷 275-288页

作者： Liyuan ZHANG Cheng ZHANG Xiqiao FENG hua jian gao School of Mechanical Engineering University of Science and Technology Beijing AML & CNMM Department of Engineering Mechanics Tsinghua University School of Engineering Brown University

Tensegrities are a class of lightweight and reticulated structures consisting of stressed strings and bars. It is shown that each prismatic tensegrity can have two self-equilibrated and stable states, leading to a snapping instability behavior under an applied torque. The predicted mechanism is experimentally validated, and can be used in areas such as advanced sensors and actuators, energy storage /alsorption equipments, and folding/unfolding devices.

关键词： tensegrity snapping instability mechanical response structure mechanics

Conservative Three-Level Linearized Finite Difference Schemes for the Fisher Equation and Its Maximum Error Estimates

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Numerical Mathematics(Theory,Methods and Applications) 2023年第3期16卷 634-667页

作者： Guang-hua gao Biao Ge Zhi-Zhong Sun College of Science Nanjing University of Posts and TelecommunicationsNanjing 210023P.R.China School of Mathematics Southeast UniversityNanjing 211189P.R.China

A three-level linearized difference scheme for solving the Fisher equation is firstly proposed in this *** has the good property of discrete conservative *** the discrete energy analysis and mathematical induction method,it is proved to be uniquely solvable and unconditionally convergent with the secondorder accuracy in both time and *** another three-level linearized compact difference scheme is derived along with its discrete energy conservation law,unique solvability and unconditional convergence of order two in time and four in *** resultant schemes preserve the maximum bound *** analysis techniques for convergence used in this paper also work for the Euler scheme,the Crank-Nicolson scheme and *** experiments are carried out to verify the computational efficiency,conservative law and the maximum bound principle of the proposed difference schemes.

关键词： Fisher equation linearized difference scheme solvability convergence conservation