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Sn-doped cobalt containing perovskite as the air electrode for highly active and durable reversible protonic ceramic electrochemical cells

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Journal of Advanced Ceramics 2024年第1期13卷 63-72页

作者： Min Fu Wenjing Hu hua Tong xin Ling Linggui Tan Fanglin chen Zetian Tao School of Resources Environment and Safety EngineeringUniversity of South ChinaHengyang 421001China Department of Mechanical Engineering University of South CarolinaColumbia 29208USA

One potential solution to the problems of energy storage and conversion is the use of reversible protonic ceramic electrochemical cells(R-PCEC),which are based on the solid oxide fuel cell(SOFC)technology and offer a flexible route to the generation of renewable fuels.However,the R-PCEC development faces a range of significant challenges,including slow oxygen reaction kinetics,inadequate durability,and poor round-trip efficiency resulting from the inadequacy of an air electrode.To address these issues,we report novel B-sites doped Pr_(0.5)Ba_(0.5)Co_(0.7)Fe_(0.3)O_(3−δ)(PBCF)with varying amounts of Sn as the air electrode for R-PCEC to further enhance electrochemical performance at lower temperatures.At 600℃,R-PCEC with an air electrode consisting of Pr_(0.5)Ba_(0.5)Co_(0.7)Fe_(0.25)Sn_(0.05)O_(3+δ)has achieved peak power density of 1.12 W∙cm^(−2) in the fuel cell mode and current density of 1.79 A∙cm^(−2) in the electrolysis mode at a voltage of 1.3 V.Moreover,R-PCECs have shown good stability in the electrolysis mode of 100 h.This study presents a practical method for developing durable high-performance air electrodes for R-PCECs.

关键词： triple conducting oxide dual-element doping protonic ceramic electrochemical cells(PCECs) catalytic

Challenging anticoagulation therapy for multiple primary malignant tumors combined with thrombosis:A case report and review of literature

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World Journal of Clinical Cases 2024年第9期12卷 1704-1711页

作者： Jia-xin chen Ling-Ling Xu Jing-Ping cheng Xun-hua Xu Department of Gerontology China Resources and Wisco General HospitalWuhan University of Science and TechnologyWuhan 430080Hubei ProvinceChina Medical College Wuhan University of Science and TechnologyWuhan 430065Hubei ProvinceChina Department of Gerontology China Resources and Wisco General HospitalWuhan 430080Hubei ProvinceChina Department of Radiology China Resources and Wisco General HospitalWuhan 430080Hubei ProvinceChina

BACKGROUND Venous thromboembolism significantly contributes to patient deterioration and mortality.Management of its etiology and anticoagulation treatment is intricate,necessitating a comprehensive consideration of various factors,including the bleeding risk,dosage,specific anticoagulant medications,and duration of therapy.Herein,a case of lower extremity thrombosis with multiple primary malignant tumors and high risk of bleeding was reviewed to summarize the shortcomings of treatment and prudent anticoagulation experience.CASE SUMMARY An 83-year-old female patient was admitted to the hospital due to a 2-wk history of left lower extremity edema that had worsened over 2 d.Considering her medical history and relevant post-admission investigations,it was determined that the development of left lower extremity venous thrombosis and pulmonary embolism in this case could be attributed to a combination of factors,including multiple primary malignant tumors,iliac venous compression syndrome,previous novel coronavirus infection,and inadequate treatment for prior thrombotic events.However,the selection of appropriate anticoagulant medications,determination of optimal drug dosages,and establishment of an appropriate duration of anticoagulation therapy were important because of concurrent thrombocytopenia,decreased quantitative fibrinogen levels,and renal insufficiency.CONCLUSION Anticoagulant prophylaxis should be promptly initiated in cases of high-risk thrombosis.Individualized anticoagulation therapy is required for complex thrombosis.

关键词： Venous thromboembolism Cancer-associated thrombosis Anticoagulation therapy iliac vein compression syndrome COVID-19 Thrombocytopenia Case report

Electrochemically recycling degraded superalloy and valorizing CO_(2)in the aff ordable borate-modified molten electrolyte

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Tungsten 2024年第2期6卷 382-393页

作者： Xiang chen Yuan Sun Long Wang xin Qu Yan Zhao Hong-Wei Xie Di-hua Wang hua-Yi Yin Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education School of MetallurgyNortheastern UniversityShenyang 110819China Institute of Metal Research Chinese Academy of ScienceShenyang 110016China School of Resource and Environmental Science Wuhan UniversityWuhan 430072China

Integrating electrochemical reduction of CO_(2)and electrochemical oxidation to recycle degraded superalloys is a promising solution to ease resource scarcity and safeguard environmental sustainability.Herein,we propose an electrochemical technique for the conversion of bulk superalloy scraps and CO_(2)into oxide powder at the anode and solid carbon at the cathode,respectively.In particular,a borax-modifi ed CaCl_(2)-based molten salt electrolyte is used for enhancing the electrochemical oxidation of superalloy scraps.At a temperature of 700℃and a voltage of 2.8 V,90.55 wt.%of alloy scraps were oxidized in a molten CaCl_(2)–NaCl–CaCO_(3)–Na_(2)B_(4)O_(7)with an acid–base ratio(K_(a/b))of 1.The synergy of Cl−and B_(4)O_(7)2−of electrolyte prevents the passivation of the alloy anode and enables continuous oxidation.Furthermore,the Ni and Co in the anode products are recovered by sulfation roasting with recovery efficiencies of 85.58%and 95.27%for Ni and Co,respectively.Overall,modulating the alkalinity of the electrolyte for enhancing oxidation/pulverization of alloy scrap anode provides new insight into electrochemically recovering superalloy scraps.

关键词： Superalloy scraps Recycling Molten salt Alkalinity Electrochemical oxidation Cobalt

Effect of tungsten carbide particles on microstructure and mechanical properties of Cu alloy composite bit matrix

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Journal of Iron and Steel Research(International) 2024年第2期31卷 519-530页

作者： Ding-qian Dong Feng-yuan He xin-hui chen Hui Li Kai-hua Shi Hui-wen Xiong xin Xiang Li Zhang College of Mechanical Engineering Sichuan University of Science and EngineeringZigong643000SichuanChina State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083HunanChina Zigong Cemented Carbide Co. Ltd.Zigong643011SichuanChina Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Science and EngineeringZigong643000SichuanChina

Copper alloy composite bit matrix was prepared by pressureless vacuum infiltration,using at least one of the three kinds of tungsten carbide particles,for example,irregular cast tungsten carbide,monocrystalline tungsten carbide and sintered reduced tungsten carbide particles.The effects of powder particle morphology,particle size and mass fraction of tungsten carbide on the microstructure and mechanical properties of copper alloy composite were investigated by means of scanning electron microscopy,X-ray diffraction and abrasive wear test in detail.The results show that tungsten carbide morphology and particle size have obvious effects on the mechanical properties of copper alloy composites.Cast tungsten carbide partially dissolved in the copper alloy binding phase,and layers of Cu_(0.3)W_(0.5)Ni_(0.1)Mn_(0.1)C phase with a thickness of around 8–15μm were formed on the edge of the cast tungsten carbide.When 45%irregular crushed fine cast tungsten carbide and 15%monocrystalline cast tungsten carbide were used as the skeleton,satisfactory comprehensive performance of the reinforced copper alloy composite bit matrix was obtained,with the bending strength,impact toughness and hardness reaching 1048 MPa,4.95 J/cm^(2) and 43.6 HRC,respectively.The main wear mechanism was that the tungsten carbide particles firstly protruded from the friction surface after the copper alloy matrix was worn,and then peeled off from the matrix when further wear occurred.

关键词： Polycrystalline diamond compact Pressureless vacuum infiltration Copper alloy composite bit matrix Microstructure characterization Abrasive wear behavior

Goal-Oriented Control Systems(GOCS):From HOW to WHAT

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 816-819页

作者： Wen-hua chen the Department of Aeronautical and Automotive Engineering Loughborough UniversityLeicestershireLE113TUU.K.

Brief:New control theory is required to underpin safe design and deployment of future highly automated systems to deal with uncertain environments and complicated tasks,enabled by AI and other advanced technologies.Goal-Oriented Control Systems offer potential to transform the control system design from currently instructing a control system how to perform a task to specifying what is to be achieved.

关键词： automated instru system

Evolution of interfacial heat transfer,contact behavior and microstructure during sub-rapid solidification of molten steel with different hydrogen contents

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Journal of Iron and Steel Research(International) 2024年第1期31卷 215-223页

作者： cheng Lu Wan-lin Wang chen-yang Zhu Jie Zeng xin-yuan Liu hua-long Li School of Metallurgy and Environment Central South UniversityChangsha410083HunanChina National Center for International Research of Clean Metallurgy Central South UniversityChangsha410083HunanChina Institute of Research of Iron and Steel ShasteelZhangjiagang215625JiangsuChina

Typical Q235 low-carbon steel samples with different hydrogen contents(0.0004,0.0008,and 0.0013 wt.%)were prepared by adjusting the environment humidity and moisture.The effects of hydrogen on interfacial heat transfer,contact behavior,and microstructure evolution were investigated using a novel droplet solidification technique.The results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%,the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m^(2),and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m^(2).Moreover,the final contact angle between the molten steel and substrate increases from 103.741°to 113.697°,and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in hydrogen.The surface roughness of the droplet bottom surface increases from 20.902 to 49.181 pm.In addition,the average grain size of the droplet increases from 14.778 to 33.548 pm with the increase in the hydrogen content.The interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process,which leads to the reduction in the interfacial heat transfer and the increase in the grain size.

关键词： Strip casting Hydrogen content Interfacial heat transfer behavior Contact behavior Microstructure evolution

Evaluation of water management on arsenic methylation and volatilization in arsenic-contaminated soils strengthened by bioaugmentation and biostimulation

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Journal of Environmental Sciences 2024年第3期137卷 515-526页

作者： Peng chen Yi Liu Guo-xin Sun State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China

Arsenic(As) fate in paddy fields has been one of the most significant current issues due to the strong As accumulation potential of rice plants under fooded conditions. However,no attempt was done to explore As methylation and volatilization under non-fooded conditions. Herein, we investigated the effects of water management on As methylation and volatilization in three arsenic-contaminated soils enhanced by biostimulation with strawderived organic matter and bioaugmentation with genetic engineered Pseudomonas putida KT2440(GE P. putida). Under fooded conditions, the application of biochar(BC), rice straw(RS)and their combination(BC+RS) increased total As in porewater. However, these effects were greatly attenuated under non-fooded conditions. Compared with RS amendment alone, the combination of GE P. putida and RS further promoted the As methylation and volatilization,and the promotion percentage under non-fooded conditions were significantly higher than that under fooded conditions. The combined GE P. putida and RS showed the highest efficiency in As methylation(88 μg/L) and volatilization(415.4 μg/(kg·year)) in the non-fooded soil with moderate As contamination. Finally, stepwise multiple linear regression analysis presented that methylated As, DOC and p H in porewater were the most important factors contributing to As volatilization. Overall, our findings suggest that combination of bioaugmentation with GE P. putida and biostimulation with RS/BC+RS is a potential strategy for bioremediation of arsenic-contaminated soils by enhancing As methylation and volatilization under non-fooded conditions.

关键词： Arsenic methylation Arsenic volatilization Water management Straw incorporation Bioaugmentation

Microstructure evolution of Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)amorphous alloy after semi-solid isothermal treatment

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China Foundry 2024年第3期21卷 287-294页

作者： xin-hua huang Jing-wen Pu Yong-xin Luo Yue-jun Ouyang School of Material Electricity and Intelligent ManufacturingHuaihua UniversityHuaihua 330031HunanChina Hunan Renewable Aluminum Innovation Research Center Huaihua UniversityHuaihua 330031HunanChina

The as-cast amorphous Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)composites,comprising in situ formedβ-Ti ductile crystalline precipitates,were prepared by water cooled copper mold suction casting.Then,the semi-solid composites were obtained after the as-cast composites were treated by semi-solid isothermal treatment.The microstructure evolution and kinetics of the composites were examined.Results show that the microstructures of both the as-cast and semi-solid composites comprise ofβ-Ti crystal phases and amorphous matrix phases.Before and after treatment,the crystals evolve from fine granular or fine dendritic crystals to coarse crystals.As the treatment temperature increasing or the time prolonging,the average crystal size gradually increases and the surface morphology of the crystals gradually becomes regular.By studying the microstructural evolution and dynamics during the isothermal treatment process,it is found that the final morphology ofβ-Ti crystals is influenced by the isothermal treatment temperature and time(t),and theβ-Ti evolution rate increases with an increase in treatment temperature.In addition,a linear relationship was observed between the size of cubicβ-Ti crystals(D^(3))and t;the growth kinetics factor K is 3.8μm^(3)·s^(-1).As the K value closes to 4μm^(3)·s^(-1),it is inferred the morphology evolution ofβ-Ti crystals is a coarsening behavior controlled by the diffusion of solute elements.

关键词： Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14) amorphous matrix composites semi-solid as-cast microstructure

Dominant woody plant species recognition with a hierarchical model based on multimodal geospatial data for subtropical forests

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Journal of Forestry Research 2024年第3期35卷 111-130页

作者： xin chen Yujun Sun State Forestry&Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry UniversityBeijing 100083People's Republic of China

Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable information.However,the potential of GEE for forest resource management has not been fully exploited.To extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast China.Spectral and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant species.The results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source independently.Similarly,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was accurate.Including terrain factors and removing spatial correlation from NFRI sample points further improved the recognition accuracy.The optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,respectively.The high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant species.Visualizing the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.

关键词： Google Earth Engine Sentinel Forest resource inventory data Dominant woody plant species Subtropics Model performance