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Evolution of nonmetallic inclusions in 80-t 9CrMoCoB large-scale ingots during electroslag remelting process

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1525-1539页

作者： Shengchao Duan Min Joo Lee Yao Su Wangzhong mu Dong Soo Kim Joo Hyun Park School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China Department of Materials Science and Chemical Engineering Hanyang UniversityAnsan 15588Rep.of Korea Department of Materials Science and Engineering KTH Royal Institute of TechnologyBrinellvägen 23Stockholm 10044Sweden Department of Engineering Science and Mathematics Division of Materials ScienceLuleåUniversity of Technology97187 LuleåSweden Casting&Forging Business Unit Nuclear Business GroupDoosan EnerbilityChangwon 51711Rep.of Korea

In combination with theoretical calculations,experiments were conducted to investigate the evolution behavior of nonmetallic inclusions(NMIs)during the manufacture of large-scale heat-resistant steel ingots using 9CrMoCoB heat-resistant steel and CaF_(2)–CaO–Al_(2)O_(3.–SiO_(2)–B_(2)O_(3.electroslag remelting(ESR)-type slag in an 80-t industrial ESR *** main types of NMI in the consumable electrode comprised pure alumina,a multiphase oxide consisting of an Al_(2)O_(3.core and liquid CaO–Al_(2)O_(3.–SiO_(2)–MnO shell,and M_(23.C_(6)carbides with an MnS *** Al_(2)O_(3.and MnS inclusions had higher precipitation temperatures than the M_(23.C_(6)-type carbide under equilibrium and nonequilibrium solidification ***,inclusions can act as nucleation sites for carbide layer *** ESR process completely removed the liquid CaO–Al_(2)O_(3.–SiO_(2)–MnO oxide and MnS inclusion with a carbide shell,and only the Al_(2)O_(3.inclusions and Al_(2)O_(3.core with a carbide shell occupied the remelted *** M_(23.C_(6)-type carbides in steel were determined as Cr_(23.C_(6)based on the analysis of transmission electron microscopy *** substitution of Cr with W,Fe,or/and Mo in the Cr_(23.C_(6)lattice caused slight changes in the lattice parameter of the Cr_(23.C_(6)***,Cr_(21.3.)Fe_(1.66)C_(6),(Cr_(19)W_(4)C_(6),Cr_(18.4)Mo_(4.6)C_(6),and Cr_(16)Fe_(5)Mo_(2)C_(6)can match the fraction pattern of Cr_(23.C_(6)*** Al_(2)O_(3.inclusions in the remelted ingot formed due to the reduction of CaO,SiO_(2),and MnO components in the liquid *** increased Al content in liquid steel or the higher supersaturation degree of Al_(2)O_(3.precipitation in the remelted ingot than that in the electrode can be attributed to the evaporation of CaF_(2)and the increase in CaO content in the ESR-type slag.

关键词： nonmetallic inclusion heat-resistant steel electroslag remelting M_(23.C_(6) carbide MnS inclusion supersaturation degree

Distributionally robust optimization configuration method for island microgrid considering extreme scenarios

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Energy and AI

Energy and AI 2024年第3期17卷 179-194页

作者： Qingzhu Zhang Yunfei mu Hongjie Jia Xiaodan Yu Kai Hou Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin300072China Key Laboratory of Smart Energy&Information Technology of Tianjin municipality Tianjin UniversityTianjin300072China

The marine climate conditions are intricate and variable. In scenarios characterized by high proportions of wind and solar energy access, the uncertainty regarding the energy sources for island microgrid is significantly exacerbated, presenting challenges to both the economic viability and reliability of the capacity configuration for island microgrids. To address this issue, this paper proposes a distributionally robust optimization (DRO) method for island microgrids, considering extreme scenarios of wind and solar conditions. Firstly, to address the challenge of determining the probability distribution functions of wind and solar in complex island climates, a conditional generative adversarial network (CGAN) is employed to generate a scenario set for wind and solar conditions. Then, by combining k-means clustering with an extreme scenario selection method, typical scenarios and extreme scenarios are selected from the generated scenario set, forming the scenario set for the DRO model of island microgrids. On this basis, a DRO model based on multiple discrete scenarios is constructed with the objective of minimizing the sum of investment costs, operation and maintenance costs, fuel purchase costs, penalty costs of wind and solar curtailment, and penalty costs of load loss. The model is subjected to equipment operation and power balance constraints, and solved using the columns and constraints generation (CCG) algorithm. Finally, through typical examples, the effectiveness of this paper’s method in balancing the economic viability and robustness of the configuration scheme for the island microgrid, as well as reducing wind and solar curtailment and load loss, is verified.

关键词： Island microgrid Extreme scenario Distributionally robust optimization Conditi onal generative adversarial network

Tailoring crystallization zinc hydroxide sulfates growth towards stable zinc deposition chemistry

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Nano Research 2024年第6期17卷 5243-5250页

作者： Kaixin Huang Xianguang Zeng Dan Zhang Yujie Wang mu Lan Chengyan Wen Yi Guo College of Materials Science and Engineering Sichuan University of Science and EngineeringZigong 643000China Department of Chemistry College of Resource and EnvironmentBaoshan UniversityBaoshan 678000China College of Optoelectronic Engineering Chengdu University of Information TechnologyChengdu 610225China

The unstable zinc anode/electrolyte interface induced by corrosion,interfacial water splitting reaction,and dendrite growth seriously degrades the performances of metal Zn anode in aqueous ***,the nucleation and growth of zinc hydroxide sulfate(ZHS),an interfacial by-product,has been tailored by Tween 80 in the electrolyte,which thereby assists in in-situ forming a dense solid electrolyte interphase(SEI)with small-sized ZHS and evenly distributed Tween *** SEI has high corrosion resistance and uniform distribution of zinc ions,which not only contributes to blocking the interfacial side reactions but also induces stable and calm zinc plating/***,the modified electrolyte can confer the assembled Zn||Zn symmetric cell with a stable operation life over 1500 h at 1 mA·cm^(−2)and 1 mAh·cm^(−2)as well as the practical Zn||NH4V4O10 full battery with a high-rate capacity of 120 mAh·g^(−1)at the current density of 5 A·g^(−1).This work provides a way for regulating and reusing interfacial by-products,and a new sight on stabilization electrodes/electrolyte interfaces.

关键词： zinc hydroxide sulfides tailoring crystallization in-situ solid electrolyte interphase electrolyte engineering strategy aqueous zinc-ion battery

Jurassic integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth Sciences 2024年第4期67卷 1195-1228页

作者： Jianguo LI Xin RAO Lin mu Xiaohui CUI Xin LI Hui LUO Peixue LIU Center for Excellence in Life and Paleoenvironment Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China Nanjing College University of Chinese Academy of SciencesNanjing 211135China

The Qinghai-Tibetan Plateau experienced a unique geological evolution during the Jurassic,driven by the termination of the Palaeotethys and the reduction of the *** Indian Plate separated from the northern margin of Gondwana and drifted northward from the Southern *** that the timing of strata serves as the basis for reconstructing geological history,the present work aimed to develop a new multiple stratigraphic and chronologic framework for the Jurassic strata of the Qinghai-Tibetan Plateau region via a synthesis of the material on lithostratigraphy,palaeontology,iso-radiometric dating,magnetostratigraphy,and other techniques with an emphasis on recent progress and *** new framework included the Jurassic System from the four major subdivisions of the plateau:the Baryan Har,Qiangtang,Lhasa-Gandise,and Southern Xizang(Himalaya).Ultimately,a more complete,refined biostratigraphic sequence was proposed,comprising the most common fossils in the plateau and those that are stratigraphically significant for the Jurassic stratigraphy,including ammonites,bivalves,brachiopods,foraminifera,radiolarians,and dinoflagellate cysts for the marine strata,and pollen and spores,and charophytes for the terrestrial *** biostratigraphic framework was correlated with the Jurassic international standard zonation of the Geological Time Scale 2020 via standard or representative species or genera of *** on this framework,we constructed a lateral correlation of the Jurassic strata between different basins of the *** palaeontologic correlation in the present work shows that the Lhasa-Gandise Block had a closer relationship with the Qiangtang Block than with the Southern Xizang Himalaya during the Jurassic ***,the Lhasa-Gandise Block and Qiangtang Block shared similar marine fauna features of the north marginal East *** contrasts the opinion suggesting that the Yarlung Zangbo Tethys was a small back-arc basin.A c

关键词： Biostratigraphy Chronostratigraphy Correlation Yarlung Zangbo suture Bangong Co-Nujiang suture Tethys

Impact of Osmotic Pressure on Seepage in Shale Oil Reservoirs

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1365-1379页

作者： Lijun mu Xiaojia Xue Jie Bai Xiaoyan Li Xueliang Han Oil and Gas Technology Research Institute PetroChina Changqing Oilfield CompanyXi’an710018China

Following large-scale volume fracturing in shale oil reservoirs,well shut-in measures are generally *** tests and field trials have underscored the efficacy of fracturing fluid imbibition during the shut-in phase in augmenting shale oil *** conventional reservoirs,shale oil reservoirs exhibit characteristics such as low porosity,low permeability,and rich content of organic matter and clay ***,the osmotic pressure effects occurring between high-salinity formation water and low-salinity fracturing fluids are *** current understanding of the mobilization patterns of crude oil in micro-pores during the imbibition process remains nebulous,and the mechanisms underpinning osmotic pressure effects are not fully *** study introduces a theoretical approach,by which a salt ion migration control equation is derived and a mathematical model for spontaneous imbibition in shale is introduced,which is able to account for both capillary and osmotic *** indicate that during the spontaneous imbibition of low-salinity fluids,osmotic effects facilitate the migration of external fluids into shale pores,thereby complementing capillary forces in displacing shale *** considering both capillary and osmotic pressures,the calculated imbibition depth increases by 12%compared to the case where only capillary forces are *** salinity difference between the reservoir and the fracturing fluids significantly influences the imbibition *** for the shutin phase reveal that the pressure between the matrix and fractures reaches a dynamic equilibrium after 28 days of *** the production phase,the maximum seepage distance in the target block is approximately 6.02 m.

关键词： Shale oil osmotic pressure numerical simulation effective seepage distance

Energy Efficiency Maximization in Mobile Edge Computing Networks via IRS assisted UAV Communications

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1865-1884页

作者： Ying Zhang Weiming Niu Supu Xiu Guangchen mu School of Electronic Information Engineering Henan Institute of TechnologyXinxiang453003China Houde College Henan Institute of TechnologyXinxiang453003China Department of Science Henan Institute of TechnologyXinxiang453003China

In this paper,we investigate the energy efficiency maximization for mobile edge computing(MEC)in intelligent reflecting surface(IRS)assisted unmanned aerial vehicle(UAV)*** particular,UAVcan collect the computing tasks of the terrestrial users and transmit the results back to them after *** jointly optimize the users’transmitted beamforming and uploading ratios,the phase shift matrix of IRS,and the UAV trajectory to improve the energy *** formulated optimization problem is highly non-convex and difficult to be solved ***,we decompose the original problem into three *** first propose the successive convex approximation(SCA)based method to design the beamforming of the users and the phase shift matrix of IRS,and apply the Lagrange dual method to obtain a closed-form expression of the uploading *** the trajectory optimization,we propose a block coordinate descent(BCD)based method to obtain a local optimal ***,we propose the alternating optimization(AO)based overall algorithmand analyzed its complexity to be equivalent or lower than existing *** results show the superiority of the proposedmethod compared with existing schemes in energy efficiency.

关键词： Mobile edge computing(MEC) unmanned aerial vehicle(UAV) intelligent reflecting surface(IRS) energy efficiency

Improved YOLOv8n Model for Detecting Helmets and License Plates on Electric Bicycles

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Computers, Materials & Continua 2024年第7期80卷 449-466页

作者： Qunyue mu Qiancheng Yu Chengchen Zhou Lei Liu Xulong Yu The College of Computer Science and Engineering North Minzu UniversityYinchuan750021China The Key Laboratory of Images and Graphics Intelligent Processing of State Ethnic Affairs Commission North Minzu UniversityYinchuan750021China

Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic *** effectively monitor compliance,the utilization of target detection algorithms through traffic cameras plays a vital role in identifying helmet usage by electric bicycle riders and recognizing license plates on electric ***,manual enforcement by traffic police is time-consuming and *** methods face challenges in accurately identifying small targets such as helmets and license plates using deep learning *** paper proposes an enhanced model for detecting helmets and license plates on electric bicycles,addressing these *** proposedmodel improves uponYOLOv8n by deepening the network structure,incorporating weighted connections,and introducing lightweight convolutional *** modifications aim to enhance the precision of small target recognition while reducing the model’s parameters,making it suitable for deployment on low-performance devices in real traffic *** results demonstrate that the model achieves an mAP@0.5 of 91.8%,showing an 11.5%improvement over the baselinemodel,with a 16.2%reduction in ***,themodel achieves a frames per second(FPS)rate of 58,meeting the accuracy and speed requirements for detection in actual traffic scenarios.

关键词： YOLOv8 object detection electric bicycle helmet detection electric bicycle license plate detection

Assessment of the triglyceride glucose index in adult patients with chronic diarrhea and constipation

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World Journal of Clinical Cases 2024年第6期12卷 1094-1103页

作者： Jing-Yi Zhu mu-Yun Liu Chang Sun Department of Gastroenterology The First Affiliated Hospital of Naval Medical UniversityShanghai 200433China Department of Gastroenterology Navy No.905 HospitalNaval Medical UniversityShanghai 200433China

BACKGROUND Accumulating evidence suggests that the gut microbiome is involved in the pathogenesis of insulin resistance(IR).However,the link between two of the most prevalent bowel disorders,chronic diarrhea and constipation,and the triglyceride glucose(TyG)index,a marker of IR,has not yet been *** To investigate the potential association between TyG and the incidence of chronic diarrhea and *** This cross-sectional study enrolled 2400 participants from the National Health and Nutrition Examination Survey database from *** was used as an exposure variable,with chronic diarrhea and constipation as determined by the Bristol Stool Form Scale used as the outcome variables.A demographic investigation based on TyG quartile subgroups was *** application of multivariate logistic regression models and weighted generalized additive models revealed potential correlations between TyG,chronic diarrhea,and *** analyses were performed to examine the stability of any potential *** In the chosen sample,chronic diarrhea had a prevalence of 8.00%,while chronic constipation had a prevalence of 8.04%.In multiple logistic regression,a more prominent positive association was found between TyG and chronic diarrhea,particularly in model 1(OR=1.45;95%CI:1.17-1.79,P=0.0007)and model 2(OR=1.40;95%CI:1.12-1.76,P=0.003.).No definite association was observed between the TyG levels and chronic *** weighted generalized additive model findings suggested a more substantial positive association with chronic diarrhea when TyG was less than 9.63.OR=1.89;95%CI:1.05-3.41,P=0.03.4),and another positive association with chronic constipation when it was greater than 8.2(OR=1.74;95%CI:1.02-2.95,P=0.0415).The results of the subgroup analyses further strengthen the extrapolation of these results to a wide range of *** Higher TyG levels were positively associated with abnormal bowel health.

关键词： Triglyceride glucose index National Health and Nutrition Examination Survey Chronic diarrhea Chronic constipation Cross-sectional study Bowel health

Layered coordination polymer with two-dimensional covalent bismuth-organic networks:Semiconductor and lithium ion storage

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Nano Research 2024年第3期17卷 2181-2185页

作者： mu-Qing Li Yulin Cao Lei Qin Hua Cheng Weimin Yang Zhouguang Lu School of Materials Science and Environmental Engineering Shenzhen Polytechnic UniversityShenzhen 518055China Industrial Training Center Shenzhen Polytechnic UniversityShenzhen 518055China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Chemistry Southern University of Science and TechnologyShenzhen 518055China

Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully synthesized.X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure,with two-dimensional(2D)Bi-DSBDC networks alternating with layers composed of dimethylamine *** material demonstrates semiconducting properties,featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2×10^(-8) S/***,electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.

关键词： bismuth layer coordination polymer(CP) semiconductor lithium ion storage