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Ramsey Numbers of Trees Versus Multiple Copies of Books

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 600-612页

作者： Xiao-bing GUO Si-nan HU Yue-jian peng School of Mathematical Sciences Luoyang Normal UniversityLuoyang 471934China School of Mathematics Hunan UniversityChangsha 410082China

Given two graphs G and H,the Ramsey number R(G,H) is the minimum integer N such that any two-coloring of the edges of K_(N) in red or blue yields a red G or a blue *** v(G) be the number of vertices of G and χ(G) be the chromatic number of *** s(G) denote the chromatic surplus of G,the number of vertices in a minimum color class among all proper χ(G)-colorings of *** showed that R(G,H)≥(v(G)-1)(χ(H)-1)+s(H) if G is connected and v(G)≥s(H).A connected graph G is H-good if R(G,H)=(v(G)-1)(χ(H)-1)+s(H).Let tH denote the disjoint union of t copies of graph H,and let G∨H denote the join of G and *** a complete graph on n vertices by K_(n),and a tree on n vertices by T_(n).Denote a book with n pages by B_(n),i.e.,the join K_(2) ∨■.Erd?s,Faudree,Rousseau and Schelp proved that T_(n) is B_(m)-good if n≥*** this paper,we obtain the exact Ramsey number of T_(n) versus 2B_(2).Our result implies that T_(n) is 2B_(2)-good if n≥5.

关键词： ramsey number ramsey goodness tree book

Modulation of d-orbital to realize enriched electronic cobalt sites in cobalt sulfide for enhanced hydrogen evolution in electrocatalytic water/seawater splitting

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Rare Metals 2024年第2期43卷 511-521页

作者： jian-peng Sun Yu Zheng Zi-Sheng Zhang Xiang-Chao Meng Zi-Zhen Li Key Laboratory of Marine Chemistry Theory and Technology(Ministry of Education) College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao266100China Shanxi Institute of Energy Taiyuan030600China Department of Chemical and Biological Engineering Faculty of EngineeringUniversity of OttawaOttawaONK1N6 N5Canada

Herein,a novel single-atomic Pt doping and interface-rich CoS/Co(OH)_(2)(Pt-CoS/Co(OH)_(2)/C)electrocatalyst has been successfully *** from precise regulation of d-orbital electronic structure modulation on Co site,Pt-CoS/Co(OH)_(2)/C exhibited remarkable HER activity and high stability for hydrogen evolution in splitting both water(73 mV@10 mA·cm^(−2)) and seawater(87 mV@10 mA·cm^(−2)).Notably,atomic Pt doping was introduced into CoS/Co(OH)_(2),which could produce local unbalanced Coulombic force and significantly increased the number of S vacancies,and then expose abundant Co ***,Co(OH)_(2) in Pt-CoS/Co(OH)_(2)/C could act as the adsorption sites for H_(2)O in hydrogen evolution reaction *** functional theory results also proved that atomic Pt doping,S vacancies and Co(OH)_(2) coupling could result in the formation of enriched electronic Co sites and optimize d_(z2) orbital electronic structure,and then realize the depth upward shift of d-band center and enhance the adsorption of H*on Co sites.

关键词： Electrocatalysts Hydrogen evolution reaction Pt-CoS/Co(OH)_(2) d-band center Electronic structure Water/seawater electrolysis

Insights on advanced g‐C_(3)N_(4)in energy storage:Applications,challenges,and future

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Carbon Energy 2024年第4期6卷 22-78页

作者： Xiaojie Yang jian peng Lingfei Zhao Hang Zhang Jiayang Li peng Yu Yameng Fan Jiazhao Wang Huakun Liu Shixue Dou School of Nuclear Technology and Chemistry&Biology Hubei Key Laboratory of Radiation Chemistry and Functional MaterialsHubei University of Science and TechnologyXianningChina Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongNorth WollongongNew South WalesAustralia State Key Laboratory of Material Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhanChina Institute of Energy Materials Science University of Shanghai for Science and TechnologyShanghaiChina

Graphitic carbon nitride(g‐C_(3)N_(4))is a highly recognized two‐dimensional semiconductor material known for its exceptional chemical and physical stability,environmental friendliness,and pollution‐free *** remarkable properties have sparked extensive research in the field of energy *** review paper presents the latest advances in the utilization of g‐C_(3)N_(4)in various energy storage technologies,including lithium‐ion batteries,lithium‐sulfur batteries,sodium‐ion batteries,potassium‐ion batteries,and *** of the key strengths of g‐C_(3)N_(4)lies in its simple preparation process along with the ease of optimizing its material *** possesses abundant amino and Lewis basic groups,as well as a high density of nitrogen,enabling efficient charge transfer and electrolyte solution ***,the graphite‐like layered structure and the presence of largeπbonds in g‐C_(3)N_(4)contribute to its versatility in preparing multifunctional materials with different dimensions,element and group doping,and conjugated *** characteristics open up possibilities for expanding its application in energy storage *** article comprehensively reviews the research progress on g‐C_(3)N_(4)in energy storage and highlights its potential for future applications in this *** exploring the advantages and unique features of g‐C_(3)N_(4),this paper provides valuable insights into harnessing the full potential of this material for energy storage applications.

关键词： g‐C_(3)N_(4) lithium‐ion batteries lithium‐sulfur batteries potassium‐ion batteries sodium‐ion batteries supercapacitors

Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： Zhen-Yu ZHOU Qiu-Yang ZHENG Yu LI Cong DING Guang-jian peng Zhong-Yu PIAO College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2D-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is *** mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and *** effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(MD)*** characterization results show that the 2D-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 *** optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5,10,and 15 N loads,*** gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

A nonradical oxidation process initiated by Ti-peroxo complex showed high specificity toward the degradation of tetracycline antibiotics

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Chinese Chemical Letters 2024年第5期35卷 366-370页

作者： jian peng Yue jiang Shuangyu Wu Yanran Cheng Jingyu Liang Yixin Wang Zhuo Li Sijie Lin College of Environmental Science and Engineering Biomedical Multidisciplinary Innovation Research InstituteShanghai East HospitalTongji UniversityShanghai 200092China Key Laboratory of Yangtze River Water Environment Shanghai Institute of Pollution Control and Ecological SecurityTongji UniversityShanghai 200092China

Nonradical oxidation has received wide attention in advanced oxidation processes for environmental *** the relationship between material characteristics and their ability to initiate nonradical oxidation processes is the key to better material design and ***,a novel titanium-based metal-organic framework MIL-125-Ti/H_(2)O_(2) system was established to show a highly selective degradation efficacy toward tetracycline ***-125-Ti with the abundance of TiO6 octahedra units was found to effectively activate H_(2)O_(2) under dark conditions by forming an oxidative Ti-peroxo *** presence of the Ti-peroxo complex,confirmed by UV-visible spectrophotometer,fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy characterizations,showed superior degradation(>95%removal rate)of oxytetracycline hydrochloride(OTC),doxycycline hydrochloride,chlortetracycline hydrochloride,and *** functional theory calculations were performed to assist the elucidation on the mechanism of H_(2)O_(2) activation and antibiotics *** MIL-125-Ti/H_(2)O_(2) system was highly resistant to halogens and background organics,and could well maintain its original catalytic activity in actual water *** retained the ability to degrade 75%of OTC within ten test *** study provides new insight into the nonradical oxidation process initiated by the unique Ti-peroxo complex of Ti-based MOF.

关键词： Nonradical oxidation Metal-organic frameworks Advanced oxidation process Ti-peroxo complex Antibiotics degradation

A 30-year overview of sodium-ion batteries

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Carbon Energy 2024年第6期6卷 56-98页

作者： Yun Gao Hang Zhang jian peng Lin Li Yao Xiao Li Li Yang Liu Yun Qiao Shu-Lei Chou School of Environmental and Chemical Engineering Shanghai UniversityShanghaiChina College of Chemistry and Materials Engineering Wenzhou UniversityWenzhouZhejiangChina Institute for Superconducting and Electronic Materials University of WollongongWollongongNew South WalesAustralia

Sodium-ion batteries(NIBs)have emerged as a promising alternative to commercial lithium-ion batteries(LIBs)due to the similar properties of the Li and Na elements as well as the abundance and accessibility of Na *** of the current research has been focused on the half-cell system(using Na metal as the counter electrode)to evaluate the performance of the cathode/anode/*** relationship between the performance achieved in half cells and that obtained in full cells,however,has been neglected in much of this ***,the trade-off in the relationship between electrochemical performance and cost needs to be given more ***,systematic and comprehensive insights into the research status and key issues for the full-cell system need to be gained to advance its ***,this review evaluates the recent progress based on various cathodes and highlights the most significant challenges for full *** strategies have also been proposed to enhance the electrochemical performance of NIBs,including designing electrode materials,optimizing electrolytes,sodium compensation,and so ***,perspectives and outlooks are provided to guide future research on sodium-ion full cells.

关键词： commercial application electrode electrolyte sodium-ion full cell strategies

Universal architecture and defect engineering dual strategy for hierarchical antimony phosphate composite toward fast and durable sodium storage

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Journal of Energy Chemistry 2024年第3期90卷 110-119,I0004页

作者： Jiawei Wu Gaoyu Wang Wei Zhang Lixiang Wang jian peng Qinghua Li Zhixin Liang Wenbo Fan Jiazhao Wang Shaoming Huang School of Materials and Energy Guangzhou Key Laboratory of Low-Dimensional Materials and Energy Storage DevicesGuangdong University of TechnologyGuangzhou 510006GuangdongChina School of Mechanical and Electrical Engineering Jiaxing Nanhu UniversityJiaxing 314001ZhejiangChina Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongInnovation CampusSquires WayNorth WollongongNSW2522Australia

Antimony(Sb)-ba sed anode materials are feasible candidates for sodium-ion batteries(SIBs) due to their high theoretical specific capacity and excellent electrical ***,they still suffer from volume distortion,structural collapse,and ionic conduction interruption upon ***,a hierarchical array-like nanofiber structure was designed to address these limitations by combining architecture engineering and anion tuning strategy,in which SbPO_(4-x) with oxygen vacancy nanosheet arrays are anchored on the surface of interwoven carbon nanofibers(SbPO_(4-x)@CNFs).In particular,bulky PO_(4)^(3-) anions mitigate the large volume distortion and generate Na_(3)PO_(4) with high ionic conductivity,collectively improving cyclic stability and ionic transport *** abundant oxygen vacancies substantially boost the intrinsic electronic conductivity of SbPO_4,further accelerating the reaction *** addition,hierarchical fibrous structures provide abundant active sites,construct efficient conducting networks,and enhance the electron/ion transport *** from the advanced structural design,the SbPO_(4-x)@CNFs electrodes exhibit outstanding cycling stability(1000 cycles at 1.0 A g^(-1) with capacity decay of 0.05% per cycle) and rapid sodium storage performance(293.8 mA h g^(-1) at 5.0 A g^(-1)).Importantly,systematic in-/ex-situ techniques have revealed the "multi-step conversion-alloying" reaction process and the "battery-capacitor dual-mode" sodium-storage *** work provides valuable insights into the design of anode materials for advanced SIBs with elevated stability and superior rate performance.

关键词： SbPO_(4) anodes Hierarchical nanostructures Oxygen vacancy Stress dispersion Sodium-ion batteries

Efficient Polytelluride Anchoring for Ultralong-Life Potassium Storage: Combined Physical Barrier and Chemisorption in Nanogrid-in-Nanofiber

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Nano-Micro Letters 2024年第4期16卷 364-378页

作者： Qinghua Li Dandan Yu jian peng Wei Zhang jianlian Huang Zhixin Liang Junling Wang Zeyu Lin Shiyun Xiong Jiazhao Wang Shaoming Huang Guangzhou Key Laboratory of Low‑Dimensional Materials and Energy Storage Devices School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006People’s Republic of China College of Materials and Chemistry China Jiliang UniversityHangzhou 310018People’s Republic of China Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongInnovation CampusSquires WayNorth WollongongNSW 2522Australia

Metal tellurides(MTes) are highly attractive as promising anodes for high-performance potassium-ion batteries. The capacity attenuation of most reported MTe anodes is attributed to their poor electrical conductivity and large volume variation. The evolution mechanisms, dissolution properties, and corresponding manipulation strategies of intermediates(K-polytellurides, K-pTe_(x)) are rarely mentioned. Herein,we propose a novel structural engineering strategy to confine ultrafine CoTe_(2) nanodots in hierarchical nanogrid-in-nanofiber carbon substrates(CoTe_(2)@NC@NSPCNFs) for smooth immobilization of K-pTe_(x) and highly reversible conversion of CoTe_(2) by manipulating the intense electrochemical reaction process. Various in situ/ex situ techniques and density functional theory calculations have been performed to clarify the formation, transformation, and dissolution of K-pTe_(x)(K_(5)Te_(3) and K_(2)Te), as well as verifying the robust physical barrier and the strong chemisorption of K_(5)Te_(3) and K_(2)Te on S, N co-doped dual-type carbon substrates. Additionally, the hierarchical nanogrid-in-nanofiber nanostructure increases the chemical anchoring sites for K-pTe_(x), provides sufficient volume buffer space, and constructs highly interconnected conductive microcircuits, further propelling the battery reaction to new heights(3500 cycles at 2.0 A g^(-1)). Furthermore, the full cells further demonstrate the potential for practical applications. This work provides new insights into manipulating K-pTe_(x) in the design of ultralong-cycling MTe anodes for advanced PIBs.

关键词： Polytelluride dissolution Nanogrid-in-nanofiber structure Physicochemical adsorption Reaction mechanism Ultralonglife potassium storage

Microfacies and diagenetic alteration in a semi-deep to deep lacustrine shale: The Yanchang Formation in the Ordos Basin, China

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Petroleum Science 2024年第3期21卷 1524-1538页

作者： Bin Bai Jing-Yue Hao Ling Fu Yu-Xi Liu jian-peng Wang Lan Wang Kevin G.Taylor Lin Ma PetroChina Research Institute of Petroleum Exploration and Development Department of Earth and Environmental Sciences University of Manchester College of Earth Sciences Jilin University Department of Chemical Engineering University of Manchester

The mineralogical development and diagenetic sequence of lacustrine shales in the Chang 7 Member of the Yanchang Formation in the Ordos Basin are detailed studied. A model of their depositional system and a diagenetic diagram are proposed in this study. Through detailed petrographic, mineralogical, and elemental analyses, four distinct shale types are identified: argillaceous shale, siliceous shale, calcareous shale, and carbonate, clay, and silt-bearing shale. The main diagenetic process in argillaceous shale is the transformation of illite to smectite, negatively impacting shale porosity. Siliceous shale undergoes carbonate cementation and quartz dissolution, contributing to increased porosity, particularly in *** shale experiences diagenesis characterised by carbonate formation and dissolution, with a prevalence of siderite. In carbonate, clay, and silt-bearing shale, the dissolution of K-feldspar contributes to illitization of kaolinite. Argillaceous shale, characterised by more clay minerals and lower mesopore volume, is identified as a potential hydrocarbon seal. Siliceous shale, with the highest pore volume and abundant inter-mineral pores, emerges as a promising shale oil reservoir. These findings contribute to a comprehensive understanding of shale properties, aiding in the prediction of shale oil exploration potential in the studied area.

关键词： Ordos Basin Yanchang Formation Chang 7 Member Diagenesis Microfacies