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Nanopore design of sulfur doped hollow carbon nanospheres for superior potassium-ion battery anodes

Rare Metals 2024年第5期43卷 2103-2114页

作者： Zhen-Dong Liu hui-yan feng Yu-Chen Wang Fei Wang Yue Liu Jian-Xiao yang Yue Gu Jun Tan Chong Ye Cheng-Zhi Zhang Ji Hua Laboratory Foshan 528000China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology College of Materials Science and EngineeringHunan UniversityChangsha 410082China

Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term *** design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling ***,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic *** finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.

关键词： Nanopore Carbon materials Sulfur doping Anode Potassium-ionbatteries

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区块链环境下多源大数据访问加密防护仿真

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计算机仿真 2024年第5期41卷 424-428页

作者：唐文春栗强强闫会峰重庆移通学院大数据学院重庆401520 公共大数据安全技术重庆市重点实验室重庆401420 重庆邮电大学软件工程学院重庆400065

为了提高多源大数据在网络中传输和存储的安全性,提出区块链技术下多源大数据加密防护算法。对多源大数据展开降维处理,减少数据计算量,提高算法的整体效率;结合Henon映射与Logistic映射设计一种双混沌加密算法,实现多源大数据初步加密... 详细信息

为了提高多源大数据在网络中传输和存储的安全性,提出区块链技术下多源大数据加密防护算法。对多源大数据展开降维处理,减少数据计算量,提高算法的整体效率;结合Henon映射与Logistic映射设计一种双混沌加密算法,实现多源大数据初步加密;利用区块链技术设计多源大数据加密防护方案,在智能合约的基础上,大数据所有者可以将双混沌加密算法加密后的密钥上传至区块链中,同时对数据的有效访问时间展开设定,在有效访问时间内只有满足访问策略的用户才可以访问多源大数据,以此实现多源大数据的加密防护。实验结果表明,所提算法加密后的数据不容易被攻击,且具有较高的运行效率和良好的加密效果。

关键词：数据降维区块链技术多源大数据双混沌加密算法数据加密防护

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基于设备状态信息的电网设备运行效率评估模型

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自动化技术与应用 2024年第1期43卷 75-79页

作者：严慧峰向颖余旭阳隋志巍国网湖南省电力有限公司湖南长沙410007 北京国电通网络技术有限公司北京100000

为提升电网设备运行效率评估的精准性及效率,设计基于设备状态信息的电网设备运行效率评估模型,以电网设备状态的描述、应用与测试量关系作为评估标准,依靠核心包、域包、记录包、电网设备包,组建电网设备状态信息模型,同时收集设备历... 详细信息

为提升电网设备运行效率评估的精准性及效率,设计基于设备状态信息的电网设备运行效率评估模型,以电网设备状态的描述、应用与测试量关系作为评估标准,依靠核心包、域包、记录包、电网设备包,组建电网设备状态信息模型,同时收集设备历史状态记录,构建状态信息数据库,利用数据包络算法进行电网设备权重相对效率评估,同时使用随机前线分析法确定设备产出情况,利用回归分析方法,调节和修正各种随机和外界环境因素,实现对电力系统设备的操作效率的精确评价。实验证明,所提方法评估结果准确,评估效率较好。

关键词：状态信息电网设备运行效率评估模型数据库

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Contributors to tidal duration asymmetry with varied coastline configurations on western shelf of Yellow Sea

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Water Science and Engineering 2024年第1期17卷 1-12页

作者： Xi feng Zheng Li hui feng Jia-yan yang Shou-peng Xie Wei-bing feng College of Harbor.Coastal and Offshore Engineering Hohai UniversityNanjing 210098China China Harbour Engineering Co. LtdBeijing 100027China Key Laboratory of Port Waterway and Sedimentation Engineering of the Ministry of CommunicationsNanjing 210029China China South-to-North Water Diversion Corporation Limited Beijing 100036China

Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is the resilience to coastal flooding,which depends on the ability to predict tidal *** duration asymmetry(TDA)is a key parameter in determination of the arrival and duration of flood *** study selected the western inner shelf of the Yellow Sea(WYS)as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level *** responses of TDA to shoreline reconstruction yielded spatial variability locally and *** the nearshore area,the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection,bottom friction,and advection,which controlled the energy transfer from M2 or S2 constituents to their overtides or compound *** sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner *** vulnerability of tidal responses was due to the displacement of the M2 amphidrome of the Kelvin wave on the WYS,which in turn changed tidal energy fluxes over the *** relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation.

关键词： Tidal duration asymmetry Western inner shelf of Yellow Sea Natural restoration Relative sea level rise Tidal amphidrome

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A real-time intelligent lithology identification method based on a dynamic felling strategy weighted random forest algorithm

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Petroleum Science 2024年第2期21卷 1135-1148页

作者： Tie yan Rui Xu Shi-hui Sun Zhao-Kai Hou Jin-Yu feng School of Petroleum Engineering Northeast Petroleum UniversityDaqing163318HeilongjiangChina Sanya Offshore Oil&Gas Research Institute Northeast Petroleum UniversitySanya572025HainanChina

Real-time intelligent lithology identification while drilling is vital to realizing downhole closed-loop drilling. The complex and changeable geological environment in the drilling makes lithology identification face many challenges. This paper studies the problems of difficult feature information extraction,low precision of thin-layer identification and limited applicability of the model in intelligent lithologic identification. The author tries to improve the comprehensive performance of the lithology identification model from three aspects: data feature extraction, class balance, and model design. A new real-time intelligent lithology identification model of dynamic felling strategy weighted random forest algorithm(DFW-RF) is proposed. According to the feature selection results, gamma ray and 2 MHz phase resistivity are the logging while drilling(LWD) parameters that significantly influence lithology identification. The comprehensive performance of the DFW-RF lithology identification model has been verified in the application of 3 wells in different areas. By comparing the prediction results of five typical lithology identification algorithms, the DFW-RF model has a higher lithology identification accuracy rate and F1 score. This model improves the identification accuracy of thin-layer lithology and is effective and feasible in different geological environments. The DFW-RF model plays a truly efficient role in the realtime intelligent identification of lithologic information in closed-loop drilling and has greater applicability, which is worthy of being widely used in logging interpretation.

关键词： Intelligent drilling Closed-loop drilling Lithology identification Random forest algorithm Feature extraction

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Effect of TiO_(2) addition on microstructures and properties of Mgo-Cao refractory aggregates

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Journal of Iron and Steel Research International 2024年第6期31卷 1547-1554页

作者： Shuai Zhang Jing-ran Wang Yuan-gao Li feng-you Li Wen yan hui-ying Shi The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Joint International Research Laboratory of Refractories and Metallurgy Wuhan 430081HubeiChina Shanxi Luweibao Taigang Refractory Co. Ltd.Taiyuan 030003ShanxiChina

MgO-CaO(40 wt.%CaO)refractory aggregates were prepared using the calcined dolomite and light-burned magnesia fine powder as raw materials and TiO_(2) as *** effect of TiO_(2) on their phase composition,microstructures and properties was investigated by X-ray diffraction and scanning electron *** properties such as bulk density,apparent porosity,relative aggregate tube strength and hydration resistance were also *** results showed that the CaTiO_(3) generated by the reaction between CaO and TiO_(2) was distributed around the CaO grain boundaries and intermittently distributed with MgO,which formed an isolation layer around CaO and greatly improved the hydration ***,the introduction of TiO_(2) promoted sintering and increased the grain size,further improving the strengths and hydration resistance of the *** addition,the most significant enhancement in the hydration resistance and strengths of the samples was achieved when 1.0-2.0 wt.%TiO_(2) was *** this case,the relative strength of aggregate increased from 33.3% to 37.3%-43.1%,and the mass gain after the hydration test decreased from 3.13% to 1.26%-1.45%.

关键词： MgO-CaO refractory aggregate TiO_(2)addition Phase composition Microstructure Hydration resistance

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Influence of powder oxidation on powder properties and formability in H13 hot-work steels processed by electron beam melting

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Journal of Iron and Steel Research International 2024年第4期31卷 924-932页

作者： Wei Liu yan Wang Li-xiong Han Ying-kang Wei hui-ping Tang Shi-feng Liu School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina School of Engineering Zhejiang University City CollegeHangzhou 310015ZhejiangChina

The oxygen content of metal powder is decisive for the recyclability of *** research on the effect of oxygen content on powder properties and material formability has practical significance for economical production with additive manufacturing while preventing the waste of ***,we deliberately oxidized the powder by baking at high temperature to increase the oxygen content in the powder and gave the calculation method of the oxygen content in the powder oxidation *** majority of oxygen element was found in the oxide particles in the powder and the oxide flm on the powder surface,which did affect the flowability of the *** is worth noting that the increase in the oxygen content does not change the phase of H13 steel,but it can promote the molten pool flow and obtain a smoother *** increase in the oxygen content in the powder is not the decisive factor for the formability and defects of the printed *** is the combined effect of the powder deformation,the increase in the oxygen content,and the impurity pollution after repeated use,which leads to the limitation of repeated utilization of the powder.

关键词： Additive manufacturing Electron beam melting H13 steel powder-Powder oxidation

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Spatiotemporal evolution and assembly processes of ammonia-oxidizing prokaryotic communities in 1 000-year-old coastal reclaimed soils

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Pedosphere 2024年第4期34卷 709-725页

作者： Sarfraz HUSSAIN Yifan YIN Senlin LIU Shanshan yan Dongjie CHEN hui CAO feng WANG Key Laboratory of Agricultural Environmental Microbiology Ministry of Agriculture and Rural AffairsCollege of Life SciencesNanjing Agricultural UniversityNanjing 210095China Institute of Eco-Environmental Sciences Ningbo Academy of Agricultural SciencesNingbo 315040China

Coastal marshes are transitional areas between terrestrial and aquatic *** are sensitive to climate change and anthropogenic *** recent decades,the reclamation of coastal marshes has greatly increased,and its effects on microbial communities in coastal marshes have been studied with great *** of these studies have explained the short-term spatiotemporal variation in soil microbial community ***,the impact of reclamation on the community composition and assembly processes of functional microbes(e.g.,ammonia-oxidizing prokaryotes)is often *** this study,using quantitative polymerase chain reaction and the Ion S5™XL sequencing platform,we investigated the spatiotemporal dynamics,assembly processes,and diversity patterns of ammonia-oxidizing prokaryotes in 1000-year-old reclaimed coastal salt *** taxonomic and phylogenetic diversity and composition of ammonia oxidizers showed apparent spatiotemporal variations with soil *** null modelling-based analysis showed that across all sites,the archaeal ammonia-oxidizing community was assembled by a deterministic process(84.71%),and deterministic processes were also dominant(55.2%)for ammonia-oxidizing bacterial communities except for communities at 60 years of *** assembly process and nitrification activity in reclaimed soils were positively *** abundance of the amoA gene and changes in ammonia-oxidizing archaeal and bacterial diversities significantly affected the nitrification activity in reclaimed *** findings suggest that long-term coastal salt marsh reclamation affects nitrification by modulating the activities of ammonia-oxidizing microorganisms and regulating their community structures and assembly *** results provide a better understanding of the effects of long-term land reclamation on soil nitrogen-cycling microbial communities.

关键词： ammonia oxidizer beta nearest taxon index coastal salt marshes community assembly deterministic process nitrification rate stochastic process

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From non-carbon host toward carbon-free lithium-sulfur batteries

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Nano Research 2024年第3期17卷 1337-1365页

作者： yanqi feng hui Liu Qiongqiong Lu School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi’an 710021China Institute of Materials Henan Key Laboratory of Advanced Conductor MaterialsHenan Academy of SciencesZhengzhou 450046China Leibniz Institute for Solid State and Materials Research(IFW)Dresden e.V. Helmholtzstraβe 2001069 DresdenGermany School of Materials&Environment Engineering Chengdu Technological UniversityChengdu 611730China

Lithium-sulfur(Li-S)batteries with advantages of high energy densities(2600 Wh·kg^(-1)/2800 Wh·L^(-1))and sulfur abundance are regarded as promising candidates for next-generation high-energy ***,the conventional carbon host used in sulfur cathodes suffers from poor chemical adsorption towards Li-polysulfides(LPS)in liquid electrolyte and sluggish redox kinetics,leading to low capacity and rate ***,carbon host used in Li metal anode with the intrinsic property of poor lithiophilicity and high Li-nucleation barrier gives rise to uncontrollable dendrite growth and further battery ***,non-carbon hosts with chemical adsorption toward LPS and catalytic activity for accelerating LPS redox conversion as well as lithiophilic property for guiding uniform Li deposition are proposed and demonstrated a high efficiency in both sulfur cathodes and Li metal *** this review,the principle and challenges of Li-S batteries are first presented,then recent work using non-carbon hosts in Li-S batteries is summarized comprehensively,and the mechanism of non-carbon host in improving sulfur utilization and stabilizing Li metal anode is discussed in ***,remaining challenges and outlook on the implementation of non-carbon host for practical carbon-free Li-S batteries are also provided.

关键词： sulfur cathode Li metal anode polysulfides adsorption catalytic effect Li dendrite carbon-free lithium-sulfur batteries

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Higher-order expansions of powered extremes of logarithmic general error distribution

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 47-54页

作者： TAN Xiao-feng LI Li-hui School of Mathematics and Statistics Southwest UniversityChongqing 400715China

In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥***-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing *** is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v).

关键词： logarithmic general error distribution convergence rate higher-order expansion powered ex-treme

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