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Emerging perovskite materials for supercapacitors:Structure,synthesis,modification,advanced characterization,theoretical calculation and electrochemical performance

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Journal of Energy Chemistry 2024年第2期89卷 41-70,I0003页

作者： yuehua Qian Qingqing Ruan Mengda Xue Lingyun Chen Department of Applied Chemistry School of Chemistry and Chemical EngineeringChongqing UniversityChongqing 401331China

As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good *** this review,the design and engineering progress of perovskite materials for supercapacitors(SCs)in recent years is ***,the review will focus on four types of perovskites,perovskite oxides,halide perovskites,fluoride perovskites,and multi-perovskites,within the context of their intrinsic structure and corresponding electrochemical performance.A series of experimental variables,such as synthesis,crystal structure,and electrochemical reaction mechanism,will be carefully analyzed by combining various advanced characterization techniques and theoretical *** applications of these materials as electrodes are then featured for various ***,we look forward to the prospects and challenges of perovskite-type SCs electrodes,as well as the future research direction.

关键词： Perovskite Modification engineering Oxygen vacancy Theoretical calculation methodology Supercapacitor

Westward Migration of Tropical Cyclone Activity in the Western North Pacific during 1982–2020:Features and Possible Causes

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Journal of Meteorological Research 2024年第1期38卷 1-9页

作者： Jian ZHONG Huadong DU Yuqin WU yuehua PENG China Satellite Maritime Tracking and Control Department Jiangyin 2144312 College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 4100733 Dalian Naval Academy Dalian 1160184 Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029

The westward migration of tropical cyclone(TC)activity has been identified in the western North Pacific(WNP),but the related features and causes remain ***,based on the best track data from China,Japan,and the US,and the NCEP–NCAR reanalysis data in 1982–2020,we investigate characteristics of the westward migration of the WNP TC activity with various metrics,and reveal possible causes for the migration of TC tracks through analyzing its seasonality and dependence on environmental *** results show that the WNP TCs show significant westward migrations in a number of metrics,including location of tracks,genesis,the first track point at which TC reaches its lifetime-maximum intensity,and the last track point in the TC *** is found that TC tracks exhibit more significant westward migrations in the easterly steering flow than in the westerly steering ***,the TC longitude shift shows notable seasonal variations,for which the TCs in the easterlies move further west than those in the westerlies during July–September,vice versa during October–*** dependence of the westward migration of TC tracks on background steering flow is associated with the different environmental *** westward shift in the westerly steering is mainly due to the reduced vertical wind shear(VWS),while the weakened zonal easterly steering and reduced VWS are both closely related to the westward migration in the easterly *** results have important implications for understanding current and future variations in TC longitude shift.

关键词： tropical cyclone westward migration steering flow vertical wind shear

Emerging two-dimensional Mo-based materials for rechargeable metal-ion batteries:Advances and perspectives

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Journal of Energy Chemistry 2024年第2期89卷 487-518,I0012页

作者： Qingqing Ruan yuehua Qian Mengda Xue Lingyun Chen Qichun Zhang Department of Applied Chemistry School of Chemistry and Chemical EngineeringChongqing UniversityChongqing 401331China Department of Materials Science and Engineering City University of Hong Kong999077Hong KongChina

With the rapid development of rechargeable metal-ion batteries(MIBs)with safety,stability and high energy density,significant efforts have been devoted to exploring high-performance electrode *** recent years,two-dimensional(2D)molybdenum-based(Mo-based)materials have drawn considerable attention due to their exceptional characteristics,including low cost,unique crystal structure,high theoretical capacity and controllable chemical ***,like other transition metal compounds,Mo-based materials are facing thorny challenges to overcome,such as slow electron/ion transfer kinetics and substantial volume changes during the charge and discharge *** this review,we summarize the recent progress in developing emerging 2D Mo-based electrode materials for MIBs,encompassing oxides,sulfides,selenides,*** introducing the crystal structure and common synthesis methods,this review sheds light on the charge storage mechanism of several 2D Mo-based materials by various advanced characterization *** latest achievements in utilizing 2D Mo-based materials as electrode materials for various MIBs(including lithium-ion batteries(LIBs),sodium-ion batteries(SIBs)and zinc-ion batteries(ZIBs))are discussed in ***,the modulation strategies for enhancing the electrochemical performance of 2D Mo-based materials are highlighted,focusing on heteroatom doping,vacancies creation,composite coupling engineering and nanostructure ***,we present the existing challenges and future research directions for 2D Mo-based materials to realize high-performance energy storage systems.

关键词： Molybdenum-based materials Two-dimensional materials Lithium-ion batteries Sodium-ion batteries Zinc-ion batteries

Solubility determination and comparison ofβ-HMX and RDX in two binary mixed solvents(acetonitrile+water,nitric acid+water)

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Chinese Journal of Chemical Engineering 2024年第5期69卷 238-249页

作者： yuehua Yao Fan Wang Yinguang Xu Zishuai Xu Lizhen Chen Jianlong Wang School of Chemistry and Chemical Engineering North University of ChinaTaiyuan 030051China Gansu Yinguang Chemical Industry Group Co.Ltd. Baiyin 730900China

In order to remove hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX),the main impurity,in process of polymorphic transformation of octrahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),the solubility ofβ-HMX and RDX in acetonitrile(ACN)+water in the temperature range of 288.15-333.15 K and in nitric acid(HNO_(3))+water in the temperature range of 298.15-333.15 K were measured by laser dynamic *** results showed that the solubility of bothβ-HMX and RDX in binary mixed solvents increased monotonously as the temperature increase at a given solvent composition or with increasing of mole fraction of solvent(ACN and nitric acid).Solubility data were well correlated by the modified Apelblat equation,Jouyban-Acree model,Yaws equation and van't Hoff equation,and the Yaws equation achieved the best fitting results according to the relative error and the mean square error ***,the solubility ofβ-HMX and RDX in binary mixed solvent was compared,based on the solubility difference and the solvent's own properties,the best separation degree ofβ-HMX and RDX was found when the mole fraction of nitric acid was 0.22 at room temperature,which provided data support for HMX crystallization in mixed *** solubility differences between RDX andβ-HMX in mixed solvents were explained from the formation of intermolecular and intramolecular hydrogen bonds.

关键词： Solubility Octrahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine Hexahydro-1,3,5-trinitro-1,3,5-triazine Separation Model Hydrogen bond

EG-STC: An Efficient Secure Two-Party Computation Scheme Based on Embedded GPU for Artificial Intelligence Systems

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Computers, Materials & Continua 2024年第6期79卷 4021-4044页

作者： Zhenjiang Dong Xin Ge yuehua Huang Jiankuo Dong Jiang Xu School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing210023China School of Computer Nanjing University of Information Science and TechnologyNanjing210044China

This paper presents a comprehensive exploration into the integration of Internet of Things(IoT),big data analysis,cloud computing,and Artificial Intelligence(AI),which has led to an unprecedented era of *** delve into the emerging trend of machine learning on embedded devices,enabling tasks in resource-limited ***,the widespread adoption of machine learning raises significant privacy concerns,necessitating the development of privacy-preserving *** such technique,secure multi-party computation(MPC),allows collaborative computations without exposing private *** its potential,complex protocols and communication interactions hinder performance,especially on resource-constrained *** to enhance efficiency have been made,but scalability remains a *** the success of GPUs in deep learning,lever-aging embedded GPUs,such as those offered by NVIDIA,emerges as a promising ***,we propose an Embedded GPU-based Secure Two-party Computation(EG-STC)framework for Artificial Intelligence(AI)*** the best of our knowledge,this work represents the first endeavor to fully implement machine learning model training based on secure two-party computing on the Embedded GPU *** experimental results demonstrate the effectiveness of *** an embedded GPU with a power draw of 5 W,our implementation achieved a secure two-party matrix multiplication throughput of 5881.5 kilo-operations per millisecond(kops/ms),with an energy efficiency ratio of 1176.3 kops/ms/***,leveraging our EG-STC framework,we achieved an overall time acceleration ratio of 5–6 times compared to solutions running on server-grade *** solution also exhibited a reduced runtime,requiring only 60%to 70%of the runtime of previously best-known methods on the same *** summary,our research contributes to the advancement of secure and efficient machine learning implementations on resource-constrained embedded

关键词： Secure two-party computation embedded GPU acceleration privacy-preserving machine learning edge computing

Detrital Zircon of Devonian Sandstones in ChangningMenglian Suture Zone, Yunnan, SW China: Implications for the Early Evolution of Paleo-Tethys

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Journal of Earth Science 2024年第3期35卷 786-796页

作者： Zhengqin Gan Qinglai Feng yuehua Wei Guichun Liu Xiaomei Nie Tianyu Zhao State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430078China School of Earth Sciences China University of GeosciencesWuhan 430074China

The Changning-Menglian suture zone is a critical tectonic belt pivotal to the evolution of the *** Wenquan Formation,characterized as turbidite deposited on the western side of the Changning-Menglian suture zone as well as the eastern edge of the Baoshan *** of detrital zircons from the Wenquan Formation reveals two significant age peaks approximately at 440 and 980 Ma,with additional age populations around 600,780,and 2500 *** major age peak at about 440 Ma is come from the andesitic-dominant volcanic arc within the Lancang Block and the western Simao Block,corroborated by the presence of andesite fragments in thin section ***,the zircons that form the secondary age peak at~980 Ma and other older age groups probably originate from the Baoshan *** on the western side of the Paleo-Tethyan ophiolites,the Wenquan Formation received detrital materials from the continental margin on the opposite ***,the main Paleo-Tethyan Ocean basin was not sufficiently broad enough to cut off the transference of detrital *** was a relatively narrow basin in the Early Devonian.

关键词： Changning-Menglian suture zone sandstone zircon Paleo-Tethys Devonian tectonics.

A universal cooperative assembly-oriented strategy for VS_(4) nanorod decoration on carbon nanostructures with enhanced magnesium storage properties

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Science China Chemistry 2024年第9期67卷 3153-3161页

作者： yuehua Man An Li Haowei Tang Jianlu Sun Yating Fei Yichen Du Xiaosi Zhou School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China

VS_(4) has a unique layered atomic chain structure and has the potential to become a high-performance cathode material of magnesium-ion batteries with a high capacity and long cycle ***,low conductivity and sluggish Mg^(2+)diffusivity during cycling limit its practical application in large-scale energy ***,a cooperative assembly-directed strategy is adopted to synthesize VS_(4) nanorods grown in situ on carbon nanotubes(CNTs/VS_(4)).VS_(4) nanorods are tightly anchored to CNTs through V-O-C interface covalent bonds,and CNTs can enhance the electronic conductivity of the *** addition,the ion insertion reaction using Mg^(2+)and Mg Cl^(+)as carriers reduces the polar barrier for divalent Mg^(2+)ion *** rationally designed architecture promotes ion diffusion and electron transfer,thus facilitating reaction *** cooperative assembly-oriented strategy can endow CNTs/VS_(4) with excellent magnesium storage properties,including a high reversible capacity of 223.2 m Ah g^(-1)at a current density of 50 m A g^(-1),a remarkable discharge capacity of 91.8 m Ah g^(-1)even at 2,000 m A g^(-1),and an impressive capacity retention of 85.2% after 1,000 cycles at 500 m A g^(-1).Moreover,this strategy can serve as a general synthetic method for the complexation of VS_(4) with other carbon nanostructures.

关键词： transition metal sulfides carbon nanostructure interfacial covalent bond magnesium-ion batteries cathode

Coupling Sb_(2)WO_(6)microflowers and conductive polypyrrole for efficient potassium storage by enhanced conductivity and K^(+) diffusivity

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Journal of Energy Chemistry 2024年第2期89卷 250-258,I0007页

作者： Ruiqi Tian Hehe Zhang Zeyu Yuan yuehua Man Jianlu Sun Jianchun Bao Ming-Sheng Wang Xiaosi Zhou School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023JiangsuChina State Key Lab of Physical Chemistry of Solid Surfaces College of MaterialsXiamen UniversityXiamen 361005FujianChina

Although metal oxide compounds are considered as desirable anode materials for potassium-ion batteries(PIBs)due to their high theoretical capacity,the large volume variation remains a key issue in realizing metal oxide anodes with long cycle life and excellent rate *** this study,polypyrroleencapsulated Sb_(2)WO_(6)(denoted Sb_(2)WO_(6)@PPy)microflowers are synthesized by a one-step hydrothermal method followed by in-situ polymerization and coating by *** the nanosheet-stacked Sb_(2)WO_(6)microflower structure,the improved electronic conductivity,and the architectural protection offered by the PPy coating,Sb_(2)WO_(6)@PPy exhibits boosted potassium storage properties,thereby demonstrating an outstanding rate property of 110.3 m A h g^(-1)at 5 A g^(-1)and delivering a long-period cycling stability with a reversible capacity of 197.2 m A h g^(-1)after 500 cycles at 1 A g^(-1).In addition,the conversion and alloying processes of Sb_(2)WO_(6)@PPy in PIBs with the generation of intermediates,K_(2)WO_(4)and K_(3)Sb,is determined by X-ray photoelectron spectroscopy,transmission electron microscopy,and exsitu X-ray diffraction during potassiation/*** functional theory calculations demonstrate that the robust coupling between PPy and Sb_(2)WO_(6)endues it with a much stronger total density of states and a built-in electric field,thereby increasing the electronic conductivity,and thus effectively reduces the K^(+)diffusion barrier.

关键词： Sb_(2)WO_(6) Polypyrrole coating Anode Potassium-ion battery In-situ TEM observation

The acyclic chromatic index of planar graphs without 4-,6-cycles and intersecting triangles

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Frontiers of Mathematics in China 2024年第3期19卷 117-136页

作者： yuehua BU Qi JIA Hongguo ZHU College of Mathematics and Computer Science Zhejiang Normal UniversityJinhua 321004China Xingzhi College Zhejiang Normal UniversityJinhua 321004China

A proper edge k-coloring is a mappingΦ:E(G)-→{1,2,...,k}such that any two adjacent edges receive different colors.A proper edge k-coloringΦof G is called acyclic if there are no bichromatic cycles in *** acyclic chromatic index of G,denoted by Xa(G),is the smallest integer k such that G is acyclically edge *** this paper,we show that if G is a plane graph without 4-,6-cycles and intersecting 3-cycles,△(G)≥9,then Xa(G)≤△(G)+1.

关键词： Acyclic edge coloring plane graph cycle