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Regulation of the pore structure of carbon nanosheets based electrocatalyst for efficient polysulfides phase conversions

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Journal of Materials Science & Technology 2024年第4期171卷 37-46页

作者： Xiaoyang Liu Jingbo zhang Kangli Liu Shijie zhang Rouhan hou Xiaoyi Hu Peng zhang Guosheng Shao State Center for International Cooperation on Designer Low-Carbon&Environmental Materials(CDLCEM) School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Zhengzhou Materials Genome Institute(ZMGI) Xingyang 450100China

The practical applications of lithium-sulfur(Li-S)batteries are hampered by the sluggish redox kinetics and polysulfides shuttle in the cyclic process,which leads to a series of problems including the loss of active materials and poor cycling *** this paper,the pore structures of carbon nanosheets based electrocatalysts were precisely controlled by regulating the content of water-soluble KCl *** relationship between pore structures and Li-S electrochemical behavior was studied,which demonstrates a key influence of pore structure in polysulfides phase *** the liquid-sloid redox reaction of polysulfides,the micropores and small mesopores(d20 nm)and macropores played a decisive *** a typical exhibition,the nickel-embedded carbon nanosheets(Ni-CNS)with a high content of large mesopores and macropores can aid Li-S batteries in exhibiting stable cycling performance(760.1 mAh g^(-1)at 1 C after 300 cycles)and superior rate capac-ity(847.8 mAh g^(-1)at 2 C).Furthermore,even with high sulfur loading(8 mg cm^(−2))and low electrolyte(E/S is around 6μL mg^(-1)),the high area capacity of 7.7 mAh cm^(−2)at 0.05 C could be *** work can provide a guideline for the design of the pore structure of carbon-based electrocatalysts toward high-efficiency sulfur species redox reactions,and afford a general,controllable,and simple approach to constructing high performance Li-S batteries.

关键词： Hierarchical porous carbon network Electrocatalyst Molten salt templating method Modified separators Li-S batteries

Machine Learning Analysis of Impact of Western US Fires on Central US Hailstorms

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Advances in Atmospheric Sciences 2024年第7期41卷 1450-1462页

作者： Xinming LIN Jiwen FAN Yuwei zhang ZJason hou Pacific Northwest National Laboratory RichlandWA 99354USA Argonne National Laboratory LemontIL 60439USA

Fires,including wildfires,harm air quality and essential public services like transportation,communication,and *** fires can also influence atmospheric conditions,including temperature and aerosols,potentially affecting severe convective ***,we investigate the remote impacts of fires in the western United States(WUS)on the occurrence of large hail(size:≥2.54 cm)in the central US(CUS)over the 20-year period of 2001–20 using the machine learning(ML),Random Forest(RF),and Extreme Gradient Boosting(XGB)*** developed RF and XGB models demonstrate high accuracy(>90%)and F1 scores of up to 0.78 in predicting large hail occurrences when WUS fires and CUS hailstorms coincide,particularly in four states(Wyoming,South Dakota,Nebraska,and Kansas).The key contributing variables identified from both ML models include the meteorological variables in the fire region(temperature and moisture),the westerly wind over the plume transport path,and the fire features(i.e.,the maximum fire power and burned area).The results confirm a linkage between WUS fires and severe weather in the CUS,corroborating the findings of our previous modeling study conducted on case simulations with a detailed physics model.

关键词： wildfire severe convective storm hailstorm machine learning

The abundance,distribution,and enrichment mechanism of harmful trace elements in coals from Guizhou,Southwestern China

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Acta Geochimica 2024年第5期43卷 889-903页

作者： Hui hou Wei Cheng Ruidong Yang Yan zhang College of Mining Guizhou UniversityGuiyangChina National and Local Joint Laboratory of Engineering for Effective Utilization of RegionalMineral Resources from Karst Areas GuiyangChina Guizhou Key Laboratory of Comprehensive Utilization of Non-Metallic Mineral Resources GuiyangChina College of Resource and Environment Engineering Guizhou UniversityGuiyangChina

Coal seams can enrich a variety of harmful trace elements under specific geological *** spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are *** harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human *** is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace *** on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of *** results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei *** enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical *** supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.

关键词： Harmful trace elements Distribution characteristics Enrichment law Geological and geochemical features Guizhou

Research on Improved MobileViT Image Tamper Localization Model

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Computers, Materials & Continua 2024年第8期80卷 3173-3192页

作者： Jingtao Sun Fengling zhang Huanqi Liu Wenyan hou School of Computer Science and Technology Xi’an University of Posts and TelecommunicationsXi’an710121China Shaanxi Key Laboratory of Network Data Analysis and Intelligent Processing Xi’an University of Posts and TelecommunicationsXi’an710121China

As image manipulation technology advances rapidly,the malicious use of image tampering has alarmingly escalated,posing a significant threat to social *** the realm of image tampering localization,accurately localizing limited samples,multiple types,and various sizes of regions remains a multitude of *** issues impede the model’s universality and generalization capability and detrimentally affect its *** tackle these issues,we propose FL-MobileViT-an improved MobileViT model devised for image tampering *** proposed model utilizes a dual-stream architecture that independently processes the RGB and noise domain,and captures richer traces of tampering through dual-stream ***,the model incorporating the Focused Linear Attention mechanism within the lightweight network(MobileViT).This substitution significantly diminishes computational complexity and resolves homogeneity problems associated with traditional Transformer attention mechanisms,enhancing feature extraction diversity and improving the model’s localization *** comprehensively fuse the generated results from both feature extractors,we introduce the ASPP architecture for multi-scale feature *** facilitates a more precise localization of tampered regions of various ***,to bolster the model’s generalization ability,we adopt a contrastive learning method and devise a joint optimization training strategy that leverages fused features and captures the disparities in feature distribution in tampered *** strategy enables the learning of contrastive loss at various stages of the feature extractor and employs it as an additional constraint condition in conjunction with cross-entropy *** a result,overfitting issues are effectively alleviated,and the differentiation between tampered and untampered regions is *** evaluations on five benchmark datasets(IMD-20,CASIA,NIST-16,Columbia and Coverage)validat

关键词： Image tampering localization focused linear attention mechanism MobileViT contrastive loss

Resource Allocation for Space-Air-Ground Integrated Networks:A Comprehensive Review

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Journal of Communications and Information Networks 2024年第1期9卷 1-23页

作者： Hui Liang Zhiqing Yang Guobin zhang Hanxu hou School of Electrical Engineering and Intelligentization Dongguan University of TechnologyDongguan 523808China Peng Cheng Laboratory Shenzhen 518055China School of Electronics and Information Engineering Shenzhen UniversityShenzhen 518061China School of Electrical Engineering and Intelligentization Dongguan University of TechonologyDongguan 523808China School of Information and Communication Engineering Guangzhou Maritime UniversityGuangzhou 510725China

The space-air-ground integrated networks (SAGIN) has emerged as a critical paradigm to address the growing demands for global connectivity and enhanced communication services. This paper gives a thorough review of the strategies and methodologies for resource allocation within SAGIN, focusing on the challenges and solutions within its complex structure. With the advent of technologies such as 6G, the dynamics of resource optimization have become increasingly complex, necessitating innovative approaches for efficient management. We examine the application of mathematical optimization, game theory, artificial intelligence (AI), and dynamic optimization techniques in SAGIN,offering insights into their effectiveness in ensuring optimal resource distribution, minimizing delays, and maximizing network throughput and stability. The survey highlights the significant advances in AI-based methods,particularly deep learning and reinforcement learning, in tackling the inherent challenges of SAGIN resource allocation. Through a critical review of existing literature, this paper categorizes various resource allocation strategies, identifies current research gaps, and discusses potential future directions. Our findings highlight the crucial role of integrated and intelligent resource allocation mechanisms in realizing the full potential of SAGIN for next-generation communication networks.

关键词： space-air-ground integrated networks resource allocation 6G optimization theory game theory artificial intelligence

Review on the recent progress of nearly zero energy building frontiers in China

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Science China(Technological Sciences) 2024年第9期67卷 2620-2636页

作者： LYU YanJie XU Wei zhang ShiCong SUN DeYu hou YueBin China Academy of Building Research Beijing 100013China

Energy efficiency improvement in Chinese construction has progressed rapidly over the past two *** zero energy buildings(NZEBs),as an integrated solution for energy-efficient construction,have gained significant attention during China's 13th Five-Year Plan period,with continuous maturation of the technical *** this study,a research framework built upon the accomplishments of China's National Key Research and Development Program is developed,and an in-depth analysis of the most cutting-edge research is provided by thoroughly reviewing the work conducted *** NZEB in China has been categorized into three stages based on the characteristics of technological development:(1)definition and standards,(2)demonstration and promotion,and(3)cross-domain *** study discerns four noteworthy development trends by examining comprehensive data spanning the last decade from 100 NZEB and zero energy ***,a comprehensive analysis of essential technology advancements in line with these identified trends is *** issues and challenges arising from the increased application of renewable energy in the context of China's carbon peak and carbon neutrality goals have also been ***,based on this analysis,the challenges and corresponding suggestions for future research directions were proposed to help guide future studies exploring emerging trends in the NZEB field.

关键词： nearly zero energy building energy efficiency load flexibility heat pump renewable energy

A multi-functional MgF_(2)/polydopamine/hyaluronan-astaxanthin coating on the biodegradable ZE21B alloy with better corrosion resistance and biocompatibility for cardiovascular application

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Journal of Magnesium and Alloys 2024年第3期12卷 1102-1116页

作者： Yachen hou Xueqi zhang Jingan Li Liguo Wang Shaokang Guan School of Materials Science and Engineering and Henan Key Laboratory of Advanced Magnesium Alloy and Key Laboratory of Materials Processing and Mold Technology(Ministry of Education) Zhengzhou UniversityZhengzhou 450001China

The cardiovascular diseases(CVD)continue to be the major threat to global public health over the years,while one of the effective methods to treat CVD is stent *** magnesium(Mg)alloys have great potential applications in cardiovascular stents benefit from their excellent biodegradability and ***,excessive degradation rate and the delayed surface endothelialization still limit their further *** this study,we modified a Mg-Zn-Y-Nd alloy(ZE21B)by preparing MgF_(2) as the corrosion resistance layer,the dopamine polymer film(PDA)as the bonding layer,and hyaluronic acid(HA)loaded astaxanthin(ASTA)as an important layer to directing the cardiovascular cells *** electrochemical test results showed that the MgF_(2)/PDA/HA-ASTA coating improved the corrosion resistance of *** cytocompatibility experiments also demonstrated that this novel composite coating also selectively promoted endothelial cells proliferation,inhibited hyperproliferation of smooth muscle cells and adhesion of *** with the HAloaded rapamycin(RAPA)coating,our MgF_(2)/PDA/HA-ASTA coating showed better blood compatibility and cytocompatibility,indicating stronger multi-functions for the ZE21B alloy on cardiovascular application.

关键词： Biodegradable ZE21B alloy Reendothelialization Surface modification Hyaluronic acid Astaxanthin.

The effect of selected alloying element additions on properties of Mg-based alloy as bioimplants： A literature review

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Frontiers of Materials Science 2013年第3期7卷 227-236页

作者： Li-Nan zhang Zeng-Tao hou Xin YE Zhao-Bin XU Xue-Ling BAI Peng SHANG Center for Translational Medicine Research and Development Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China

This review investigates the current application limitations of Mg and Mg alloys. The key issues hindering the application of biodegradable Mg alloys as implants are their fast degradation rate and biological consideration. We have discussed the effect of some selected alloying element additions on the properties of the Mg-based alloy, especially the nutrient elements in human （Zn, Mn, Ca, St）. Different grain sizes, phase constituents and distributions consequently influence the mechanical properties of the Mg alloys. Solution strengthening and precipitation strengthening are enhanced by the addition of alloying elements, generally improving the mechanical properties. Besides, the hot working process can also improve the mechanical properties. Combination of different processing steps is suggested to be adopted in the fabrication of Mg-based alloys. Corrosion properties of these *** alloys have been measured in vitro and in vivo. The degradation mechanism is also discussed in terms of corrosion types, rates, by- products and response of the surrounding tissues. Moreover, the clinical response and requirements of degradable implants are presented, especially for the nutrient elements （Ca, Mn, Zn, Sr）. This review provides information related to different Mg alloying elements and presents the promising candidates for an ideal implant.

关键词： magnesium alloy alloying element corrosion biodegradation

Preparation of Laser Cladding Coating Undercooling Cu-based Alloy and Co on Non-equilibrium Solidification Structure

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 463-472页

作者：田徐铭 CAO Shichao hou Kai hou Xiaopeng WANG Hongfu 张煜 Department of Outpatient Xinzhou People’s HospitalXinzhou 034099China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Department of Neurosurgery Xinzhou People’s HospitalXinzhou 034099China Department of Orthopedics Xinzhou People’s HospitalXinzhou 034099China

The effect of the gradient content of Co element on the solidification process of Cu-based alloy under deep under cooling conditions was *** non-equilibrium solidification structure of the under cooled alloy samples were *** is found that the rapidly solidified alloy has undergone twice grain refinement during the undercooling *** and significance of the maximum undercooling refinement structure of Cu60Ni35Co5 at T=253 K were ***-density defects were observed,such as dislocations,stacking faults networks,and twinning *** standard FCC diffraction pattern represents that it is still a single-phase *** on the metallographic diagram,EBSD and TEM data analysis,it is illustrated that the occurrence of grain refinement under high undercooling is due to stress induced *** addition,the laser cladding technology is used to coat Co-based alloy(Stellite12) coating on 304 stainless steel substrate;the microstructure of the coating cross-section was *** was found that the microstructure of the cross-section is presented as columnar crystals,planar crystals,and disordered growth direction,so that the coating has better hardness and wear *** electrochemical corrosion of the substrate and coating,it can be seen that the Co and Cr elements present in the coating are more likely to form a dense passivation film,which improved the corrosion resistance of the coating.

关键词： non-equilibrium solidification structure undercooling recrystallization laser cladding coating