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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

Elevated CO_(2) increases soil redox potential by promoting root radial oxygen loss in paddy field

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Journal of Environmental Sciences 2024年第2期136卷 11-20页

作者： Jie Li han Zhang Wenyi Xie Cheng liu Xiaoyu liu Xuhui Zhang Lianqing Li Genxing Pan Institute of Resource Ecosystem and Environment of AgricultureNanjing Agricultural UniversityNanjing 210095China College of Agriculture Nanjing Agricultural UniversityNanjing 210095China

Soil redox potential(Eh)plays an important role in the biogeochemical cycling of soil *** its effect soil process and nutrients'availability under elevated atmospheric CO_(2) concentration and warming has seldom been ***,in this study,a field experiment was used to elucidate the effect of elevated CO_(2) concentration and warming on soil Eh,redox-sensitive elements and root radial oxygen loss(ROL).We hypothesized elevated CO_(2) and warming could alter soil Eh by promoting or inhibiting *** found that soil Eh in the rhizosphere was significantly higher than that of *** CO_(2) enhanced soil Eh by 11.5%,which corresponded to a significant decrease in soil Fe^(2+)and Mn^(2+)*** elevated CO_(2),the concentration of Fe^(2+)and Mn^(2+)decreased by 14.7%and 13.7%,*** also found that elevated CO_(2) altered rice root aerenchyma structure and promoted rice root *** elevated CO_(2),rice root ROL increased by 79.5%and 112.2%for Yangdao 6 and Changyou 5,*** had no effect on soil Eh and rice root *** warming increased the concentration of Mn^(2+)and SO_(4)^(2-)by 4.9%and 19.3%,*** was a significant interaction between elevated CO_(2) and warming on Fe^(2+)and Mn^(2+).Under elevated CO_(2),warming had no effect on the concentration of Fe^(2+)but decreased Mn^(2+)concentration *** study demonstrated that elevated atmospheric CO_(2) in the future could increase soil Eh by promoting rice root ROL,which will alter some soil nutrients'availability,such as Fe^(2+)and Mn^(2+).

关键词： Atmospheric CO_(2)enrichment Global warming Soil redox potential FACE Rice root aerenchyma

Recent Progress in Optical Sensors Based on MXenes Quantum Dots and MXenes Nanosheets

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Journal of Analysis and Testing 2024年第1期8卷 95-113页

作者： Chunxiao Lin Xinhong Song Weilan Ye ting liu Mingcong Rong Li Niu Guangzhou Key Laboratory of Sensing Materials and Devices/Center for Advanced Analytical Science/School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou 510006China College of Ocean Science and Engineering Shanghai Maritime UniversityShanghai 201306China

In recent years,MXenes,as a new promising two-dimensional material,have received extensive attentions in the fields of environmental remediation,catalysts,sensors,and energy *** broaden the applications of MXenes in sensing,MXenes nanosheets(MNSs) and MXenes quantum dots(MQDs) are prepared by physical etching or chemical *** are monolayered or multilayered MXenes nanosheets within several nanometers in height,and can serve as the perfect reaction substrate and fluorescence *** are spherical,fluorescent MXenes QDs within several nanometers in size,which possess favorable stability and photo *** the distinct features such as high conductivity,favorable hydrophilicity,biocompatibility,abundant surface functional groups,and easy functionalization,MNSs and MQDs show potential applications in the fields of anti-counterfeiting,environmental monitoring,biosensing and *** review focuses on the research of MNS s/MQDs-based optical sensors,including colorimetric sensors,fluorescence sensors,electrochemiluminescence sensors,surface plasmon resonance sensors,and surface-enhanced Raman scattering ***,the current challenges and prospects concerning MNSs/MQDs-based optical sensing techniques are discussed.

关键词： MXenes quantum dots Fluorescence Colorimetry Electrochemiluminescence Surface plasmon resonance

Study of PAPR mitigation in OFDM-VLC system by SCMA codebook design

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Optoelectronics Letters 2024年第9期20卷 543-548页

作者： YANG ting LI Ganggang liu Tao WANG Ping WANG Zhao School of Telecommunications Engineering Xidian UniversityXi'an 710071China

Traditional orthogonal frequency division multiplexing(OFDM)based visible light communication(VLC)system is susceptible to high peak-to-average power ratio(PAPR),thus leading to low power *** address this issue,a sparse code multiple access(SCMA)codebook design method has been proposed to lower the PAPR of the clipping based OFDM-VLC system.

关键词： OFDM SCMA code

Comparing the temperature sensitivity of organic matter decomposition in oxic and oxygen-deprived soils

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Soil Ecology Letters 2024年第1期6卷 29-32页

作者： Zhenhui Jiang Xin Wang ting liu Xiaojuan Feng State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeiing 100093China University of Chinese Academy of Sciences Bejing 100049China State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityHangzhou 311300China Henan Key Laboratory of Ecological Environment Protection and Restoration of Yellow River Basin Yellow River Institute of Hydraulic ResearchZhengzhou 450003China

No consistent variation was found in soil respiration Q10 under various O2 *** C quality had a strong effect on Q10 in oxic soils.N limitation had a large impact on Q10 in soils under O2 *** studies on the temperature sensitivity(Q10)of soil organic matter(SOM)decomposition mainly focus on aerobic ***,varia-tions and determinants of Q10 in oxygen(O2)-deprived soils remain *** we incubated three grassland soils under oxic,suboxic,and anoxic conditions subjected to varying temperatures to compare variations in Q10 in relation to changing *** consistent variation was found in Q10 under various O2 *** analysis of edaphic properties demon-strated that substrate carbon quality showed a strong influence on Q10 in oxic soils,whereas nitrogen limitation played a more important role in suboxic and anoxic *** results suggest that substrate carbon quality and nitrogen limitation may play roles of varying importance in determining the temperature sensitivity of SOM decomposition under various O2 conditions.

关键词： oxygen-limited conditions temperature sensitivity soil respiration carbon substrate nitrogen limitation

NaBH4-induced phase transition of CoSe_(2) with abundant Se deficiency for acidic oxygen reduction to hydrogen peroxide

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Rare Metals 2024年第2期43卷 500-510页

作者： Cai-Di han Yong-Chao Zhang Qian Zhang Jin-ting Wu Jian Gao Ji-Jun Zou Xiao-Dong Zhu State Key Laboratory Base of Eco-Chemical Engineering College of Chemical Engineering Qingdao University of Science and TechnologyQingdao266042China Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

Electrocatalytic oxygen reduction(ORR)via the 2e−pathway to form H_(2)O_(2) in acidic medium has attracted extensive ***,the low activity,insufficient selectivity and high cost of catalysts have been the ***,CoSe_(2) with abundant Se deficiency was synthesized by a simple hydrothermal method,and the addition of NaBH4-induced CoSe_(2) phase transition from orthorhombic to cubic phase with more Se *** cubic phase CoSe_(2) with abundant Se deficiency can effectively regulate the surface electronic structure with suitable binding energies of*OOH and*O,which shows high activity,selectivity and long-term stability for acidic ORR to H_(2)O_(2).The onset potential is as low as 0.73 V *** hydrogen electrode(RHE),the H_(2)O_(2) selectivity is 84%(0 V ***),and the average electron transfer number is about ***,the H_(2)O_(2) yield measured using a flow cell is as high as 115.92 mmol·gcat.^(−1)·h^(−1) and the Faradaic efficiency is 70%at 0 V ***,which presents high potential in electrocatalytic acidic ORR to H_(2)O_(2) and organic pollutant degradation using the electron-Fenton process.

关键词： Se defected CoSe_(2) Crystal phase transition Electrocatalysis Acidic oxygen reduction Hydrogen peroxide

Isogeometric Analysis of Hyperelastic Material Characteristics for Calcified Aortic Valve

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2773-2806页

作者： Long Chen ting Li Liang liu Wenshuo Wang Xiaoxiao Du Wei Wang School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai200093China Department of Cardiac Surgery Zhongshan HospitalFudan UniversityShanghai200093China School of Mechanical Engineering and Automation Beihang UniversityBeijing100191China

This study explores the implementation of computed tomography(CT)reconstruction and simulation techniques for patient-specific valves,aiming to dissect the mechanical attributes of calcified valves within transcatheter heart valve replacement(TAVR)*** order to facilitate this exploration,it derives pertinent formulas for 3D multi-material isogeometric hyperelastic analysis based on Hounsfield unit(HU)values,thereby unlocking foundational capabilities for isogeometric analysis in calcified aortic valves.A series of uniaxial and biaxial tensile tests is executed to obtain an accurate constitutive model for calcified active *** mitigate discretization errors,methodologies for reconstructing volumetric parametric models,integrating both geometric and material attributes,are *** these analytical formulas,constitutive models,and precise analytical models to isogeometric analyses of calcified valves,the research ascertains their close alignment with experimental results through the close fit in displacement-stress curves,compellingly validating the accuracy and reliability of the *** study presents a step-by-step approach to analyzing themechanical characteristics of patient-specific valves obtained fromCT images,holding significant clinical implications and assisting in the selection of treatment strategies and surgical intervention approaches in TAVR procedures.

关键词： Calcified aortic valves tensile test constitutive relations CT reconstruction isogeometric hyperelastic analysis

Flexible and Stretchable Electrodes for In Vivo Electrophysiological and Electrochemical Monitoring

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Chinese Journal of Chemistry 2024年第13期42卷 1523-1545页

作者： Kai-Kai Sheng Yi-Fei Lu Wen-ting Fan Yan-Ling liu College of Chemistry and Molecular Sciences Wuhan University WuhanHubei 430072China Core Facilty of Wuhan University WuhanHubei 430072China

In vivo monitoring of bioelectrical and biochemical signals with implanted electrodes has received great interest over the past ***,this faces huge challenges because of the severe mechanical mismatch between conventional rigid electrodes and soft biological *** recent years,the emergence of flexible and stretchable electrodes offers seamless and conformable biological-electronic interfaces and has demonstrated significant advantages for in vivo electrochemical and electrophysiological *** review first summarizes the strategies for electrode fabrication from the point of substrate and conductive ***,recent progress in electrode functionalization for improved performance is ***,the advances of flexible and stretchable electrodes in exploring bioelectrical and biochemical signals are ***,we present some challenges and perspectives ranging from electrode fabrication to application.

关键词： Flexible electrodes Conductive materials Stretchable structures Electrode functionalization In vivo monitoring Biochemical signals Bioelectrical signals

Androgen signaling inhibits de novo lipogenesis to alleviate lipid deposition in zebrafish

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Zoological Research 2024年第2期45卷 355-366页

作者： Jing-Yi Jia Guang-Hui Chen ting-ting Shu Qi-Yong Lou Xia Jin Jiang-Yan He Wu-han Xiao Gang Zhai Zhan Yin College of Fisheries Huazhong Agriculture UniversityWuhanHubei 430070China State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhanHubei 430072China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes Chinese Sturgeon Research InstituteChina Three Gorges CorporationYichangHubei 443100China Hubei Hongshan Laboratory Huazhong Agriculture UniversityWuhanHubei 430070China Innovative Academy of Seed Design Chinese Academy of SciencesBeijing 100049China

Testosterone is closely associated with lipid metabolism and known to affect body fat composition and muscle mass in ***,the mechanisms by which testosterone acts on lipid metabolism are not yet fully understood,especially in *** this study,cyp17a1-/-zebrafish(Danio rerio)exhibited excessive visceral adipose tissue(VAT),lipid content,and up-regulated expression and activity of hepatic de novo lipogenesis(DNL)*** assay for transposase accessible chromatinwithsequencing(ATAC-seq)results demonstrated that chromatin accessibility of DNL genes was increased in cyp17a1-/-fish compared to cyp17a1+/+male fish,including stearoyl-CoA desaturase(scd)and fatty acid synthase(fasn).Androgen response element(ARE)motifs in the androgen signaling pathway were significantly enriched in cyp17a1+/+male fish but not in cyp17a1-/-*** androgen receptor(ar)-/-and wildtype(WT)zebrafish administered with Ar antagonist flutamide displayed excessive visceral adipose tissue,lipid content,and up-regulated expression and activity of hepatic de novo lipogenesis *** Ar agonist BMS-564929 reduced the content of VAT and lipid content,and down-regulated acetyl-CoA carboxylase a(acaca),fasn,and scd ***,the rescue effect of testosterone on cyp17a1-/-fish in terms of phenotypes was abolished when ar was additionally ***,these findings reveal that testosterone inhibits lipid deposition by down-regulating DNL genes via Ar in zebrafish,thus expanding our understanding of the relationship between testosterone and lipid metabolism in teleosts.

关键词： Cyp17a1 Testosterone Androgen receptor De novo lipogenesis Fatty acid synthesis