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Enhanced piezoelectric properties and electrical resistivity in CaHfO_(3)modified BiFeO_(3)eBaTiO_(3)lead-free piezoceramics

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Journal of Materiomics 2024年第2期10卷 416-422页

作者： Jianwei Zhao Hailan Qin Xiaoxin Chen Shuhui yu Dawei Wang Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055GuangdongChina College of Materials Science and Engineering Guilin University of TechnologyGuilin541004GuangxiChina Functional Materials and Acousto-Optic Instruments Institute School of Instrumentation Science and EngineeringHarbin Institute of TechnologyHarbin150080HeilongjiangChina

A number of CaHfO_(3)modified BiFeO_(3)-0.33BaTiO_(3)(BF-0.33BT-xCH)lead-free piezoceramics were fabri-cated through the solid-state sintering method and comprehensively investigated in this *** the optimal sintering temperature,all compositions display a typical perovskite structure in a pseudo-cubic phase with slightly larger lattice parameters as the CH content *** electrical resistivity is highly enhanced due to the addition of ***,including the grain morphology,core-shell structure,and chemistry inhomogeneities,are demonstrated upon different BF-0.33BT-xCH *** particular,the core-shell structures with non-uniform element distributions in the compositions can be eliminated by adding sufficient CH content(x>0.05).The highest saturation polarization(40.1 mC/cm^(2)),remnant polarization(26.8 mC/cm^(2)),and converse piezoelectric coefficient(290 pm/v)are achieved in the BF-0.33BT-0.01CH piezoceramic,which are significantly enhanced in comparison with the undoped BF-0.33BT *** further increasing the CH content,the piezoelectric properties of BF-0.33BT-xCH ceramics decline rapidly,and they start to exhibit characteristics of relaxor ferroelectrics.

关键词： Lead-free piezoelectric CaHfO_(3)modified BF-0.33BT Core-shell structure Impedance Piezoelectric property

农村劳动力转移对耕地利用可持续集约化的影响

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农业工程学报 2024年

作者：陈梦涵吕晓 SERGEY yu.Solodovnikov TATSIANA v.Serhiyevich 东北大学文法学院白俄罗斯国立技术大学

厘清农村劳动力转移与耕地利用可持续集约化之间的关系对于促进农业可持续发展具有重要意义。该研究基于1990—2020年中国省级面板数据，采用超效率SBM模型测算耕地利用可持续集约化水平，运用面板门槛模型探讨农村劳动力转移对耕地利... 详细信息

厘清农村劳动力转移与耕地利用可持续集约化之间的关系对于促进农业可持续发展具有重要意义。该研究基于1990—2020年中国省级面板数据，采用超效率SBM模型测算耕地利用可持续集约化水平，运用面板门槛模型探讨农村劳动力转移对耕地利用可持续集约化的影响效应。结果表明：1)1990—2020年中国耕地利用可持续集约化水平总体呈先下降后上升的趋势，区域间差异显著；2）农村劳动力转移对耕地利用可持续集约化存在非线性影响，当农村劳动力转移水平小于0.351时，农村劳动力转移不利于耕地利用可持续集约化的增长；超过这一门槛后，农村劳动力转移对耕地利用可持续集约化产生显著的增长效应；3）农村劳动力转移对耕地利用可持续集约化的影响存在非均衡效应，即农村劳动力转移对农业发达地区与平原地区的促进作用显著，但对农业欠发达地区与山地地区的促进作用尚不显著。基于此，应合理引导农村冗余劳动力非农转移，以推动耕地利用可持续集约化转型；同时，应注意耕地利用可持续集约化提升的自然环境禀赋与农业经济发展水平制约，因地制宜的探索适宜地区条件的耕地利用可持续集约化发展路径。

关键词：农村劳动力转移耕地利用可持续集约化超效率SBM模型门槛模型非均衡效应

Enhancing the activity and succinyl-CoA specificity of 3-ketoacyl-CoA thiolase Tfu_0875 through rational binding pocket engineering

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Synthetic and Systems Biotechnology 2024年第3期9卷 558-568页

作者： Lixia Liu Shuang Liu Xiangyang Hu Shenghu Zhou yu Deng National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing Jiangnan University1800 Lihu RoadWuxiJiangsu214122China Jiangsu Provincial Research Center for Bioactive Product Processing Technology Jiangnan University1800 Lihu RoadWuxiJiangsu214122China

The 3-ketoacyl-CoA thiolase is the rate-limiting enzyme for linear dicarboxylic acids ***,the promiscuous substrate specificity and suboptimal catalytic performance have restricted its *** we present both biochemical and structural analyses of a high-efficiency 3-ketoacyl-CoA thiolase Tfu_***,Tfu_0875 displayed heightened activity and substrate specificity for succinyl-CoA,a key precursor in adipic acid *** enhance its performance,a deep learning approach(DLKcat)was employed to identify effective mutants,and a computational strategy,known as the greedy accumulated strategy for protein engineering(GRAPE),was used to accumulate these effective *** the mutants,Tfu_0875N249W/L163H/E217L exhibited the highest specific activity(320%of wild-type Tfu_0875),the greatest catalytic efficiency(kcat/KM=1.00 min-1mM-1),the highest succinyl-CoA specificity(KM=0.59 mM,28.1%of Tfu_0875)and dramatically reduced substrate binding energy(-30.25 kcal mol^(-1)v.s.-15.94 kcal mol^(-1)).A structural comparison between Tfu_0875N249W/L163H/E217L and the wild type Tfu_0875 revealed that the increased interaction between the enzyme and succinyl-CoA was the primary reason for the enhanced enzyme *** interaction facilitated rapid substrate anchoring and ***,a reduced binding pocket volume improved substrate specificity by enhancing the complementarity between the binding pocket and the substrate in stereo ***,our rationally designed mutant,Tfu_0875N249W/L163H/E217L,increased the adipic acid titer by 1.35-fold compared to the wild type Tfu_0875 in shake *** demonstrated enzymatic methods provide a promising enzyme variant for the adipic acid *** above effective substrate binding pocket engineering strategy can be beneficial for the production of other industrially competitive biobased chemicals when be applied to other thiolases.

关键词： Adipic acid 3-Ketoacyl-CoA thiolase Claisen condensation Deep learning GRAPE strategy

Engineered interface of three-dimensional coralliform NiS/FeS_(2)heterostructures for robust electrocatalytic water cleavage

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Nano Research 2024年第6期17卷 4693-4701页

作者： Xin yu Jing Mei Yeshuang Du Xiaohong Cheng Xing Wang Qi Wu State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430073China Hubei Key Laboratory of Pollutant Analysis&Reuse Technology College of Chemistry and Chemical EngineeringHubei Normal UniversityHuangshi 435002China Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053China

Heterojunction structures improve the intrinsic activity of electrocatalysts by enhancing the charge transfer between the catalyst and the *** this paper,the NiS/FeS_(2)heterostructured electrocatalyst is fabricated by a simple sulfidation method using an interface engineering strategy to adjust the surface electron density of the *** expected,NiS/FeS_(2)electrocatalyst exhibits superior activity and durable oxygen evolution reaction(OER)stability,requiring only a low overpotential of 183 mv to achieve a current density of 10 mA·cm^(−2)and can be stable for more than 80 h,superior to NiS,FeS_(2)electrocatalyst individually,and precious RuO_(2).Notably,NiS/FeS_(2)is also a good bifunctional electrocatalyst with good overall water splitting performance,and it only requires a voltage 1.56 v to obtain a current density of 10 mA·cm^(−2)for more than 12 ***,the NiS/FeS_(2)hybridization facilitates the formation of coral-like structures,increasing the electrochemical surface area(ECSA)and enhancing the charge transfer efficiency,thus leading to excellent electrocatalytic *** work proposes a constructive strategy for designing efficient electrocatalysts based on interface engineering,and lays a foundation for designing a new class of electrocatalysts.

关键词： NiS/FeS_(2) interface engineering nanorods bifunctional water splitting

Electrospun carbon nanofiber-supported v_(2)O_(3) with enriched oxygen vacancies as a free-standing high-rate anode for an all-vanadium-based full battery

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Carbon Energy 2024年第9期6卷 15-28页

作者： Qi Lai Bincen Yin yu Dou Qing Zhang yunhai Zhu Yingkui Yang School of Chemistry and Materials Science South-Central Minzu UniversityWuhanChina State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhanChina

Synergistic regulation of hierarchical nanostructures and defect engineering is effective in accelerating electron and ion transport for metal oxide ***,carbon nanofiber-supported v_(2)O_(3) with enriched oxygen vacancies(Ov-v_(2)O_(3)@CNF)was fabricated using the facile electrospinning method,followed by thermal *** from the traditional particles embedded within carbon nanofibers or irregularly distributed between carbon nanofibers,the free-standing Ov-v_(2)O_(3)@CNF allows for v_(2)O_(3) nanosheets to grow vertically on one-dimensional(1D)carbon nanofibers,enabling abundant active sites,shortened ion diffusion pathway,continuous electron transport,and robust structural ***,density functional theory calculations confirmed that the oxygen vacancies can promote intrinsic electron conductivity and reduce ion diffusion energy ***,the Ov-v_(2)O_(3)@CNF anode delivers a large reversible capacity of 812 mAh g^(-1) at 0.1 A g^(-1),superior rate capability(405 mAh g^(-1) at 5 A g^(-1)),and long cycle life(378 mAh g^(-1) at 5 A g^(-1) after 1000 cycles).Moreover,an all-vanadium full battery(v2O5//Ov-v_(2)O_(3)@CNF)was assembled using an Ov-v_(2)O_(3)@CNF anode and a v2O5 cathode,which outputs a working voltage of 2.5 v with high energy density and power density,suggesting promising practical *** work offers fresh perspectives on constructing hierarchical 1D nanofiber electrodes by combining defect engineering and electrospinning technology.

关键词： electrospun electrode full battery oxygen vacancy vanadium trioxide

Enhanced Ethylene Production from Electrocatalytic Acetylene Semi-hydrogenation Over Porous Carbon-Supported Cu Nanoparticles

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Transactions of Tianjin University 2024年第4期30卷 297-304页

作者： Li Li Fanpeng Chen Bo-Hang Zhao Yifu yu Institute of Molecular Plus Department of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China

Electrocatalytic semi-hydrogenation of acetylene(C_(2)H_(2))over copper nanoparticles(Cu NPs)offers a promising non-petroleum alternative for the green production of ethylene(C2H4).However,server hydrogen evolution reaction(HER)competition in this process prominently decreases C2H4 selectivity,thereby hindering its practical ***,a Cu-based composite catalyst,wherein porous carbon with nanoscale pores was used as a support,is constructed to gather the C_(2)H_(2) feedstocks for suppressing the undesirable *** a result,the as-prepared catalyst exhibited C_(2)H_(2) conversion of 27.1%and C_(2)H_(4) selectivity of 88.4%at a C2H4 partial current density of 0.25 A/cm^(2) under optimal−1.0 v versus reversible hydrogen electrode(RHE)under the simulated coal-derived C_(2)H_(2) atmosphere,significantly outperforming the single Cu NPs *** addition,a series of in situ and ex situ experimental results show that not only the porous nature of the carbon support but also the stabilized Cu^(0)–Cu^(+) dual active sites through the strong metal–support interactions enhance the adsorption capacity of C_(2)H_(2),leading to high C_(2)H_(2) partial pressure,restraining the HER and thus improving the C2H4 selectivity.

关键词： Electrocatalysis Cu-based catalyst Hydrogenation Ethylene Selectivity

Te-doped Fe3O4 flower enabling low overpotential cycling of Li-CO2 batteries at high current density

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Double active sites promoting hydrogen evolution activity and stability of CoRuOH/Co_(2)P by rapid hydrolysis

结构化学 2024年第3期43卷 25-32页

作者： Huyi yu Renshu Huang Qian Liu Xingfa Chen Tianqi yu Haiquan Wang Xincheng Liang Shibin Yin Guangxi Key Laboratory of Electrochemical Energy Materials School of Chemistry and Chemical EngineeringGuangxi University100 Daxue RoadNanning530004China

Li-CO2 batteries(LCBs)suffer from high overpotentials caused by sluggish CO2 reaction *** work designs a Te-doped Fe3O4(Te-Fe3O4)flower-like microsphere catalyst to lower the overpotential and improve the reversibility of *** results reveal that Te doping modifies the electronic structure of Fe3O4 and reduces the *** stable Te-O bond between Te and C2O4-could effectively inhibit the dispro-portionation reaction of the latter,enabling the Te-Fe3O4 cathodes to exhibit a remarkable capacity(9485 mAh g-1)and a long cycling life(155 cycles)with an overpotential of 1.21 v and an energy efficiency of about 80％at a high current density(2000 mA g-1).Through the interaction between Te and Li2C2O4 to inhibit the dispro-portionation reaction,this work successfully achieves long-term cycling of LCBs with low overpotential at high current density.

关键词： Li-CO_2 batteries Catalyst Tellurium Li_2C_2O_4 Large current density

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Chinese Chemical Letters 2024年第7期35卷 206-211页

作者： Bin Dong Ning yu Qiu-yue Wang Jing-Ke Ren Xin-yu Zhang Zhi-Jie Zhang Ruo-Yao Fan Da-Peng Liu Yong-Ming Chai State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580China

Cobalt-based phosphides show excellent hydrogen evolution reaction(HER)performance,however,improving the intrinsic activity and stability of it in alkaline electrolyte still remains a ***,CoRuOH/Co_(2)P/CF with heterojunction structure was developed by means of molten salt and rapid hydrolysis(30 s).The OH-from rapid surface hydrolysis of Co_(2)P as a hydrogen adsorption site can facilitate the formation of thin CoRuOH layer as a water dissociation site,which may bring out better synergistic effect for alkaline ***,the covering of CoRuOH can improve the stability of Co_(2)P for *** drives at 100 mA/cm^(2),it only requires overpotential of 81 mv in 1.0 mol/L KOH(25℃).Even at higher current density(1000 mA/cm^(2)),CoRuOH/Co_(2)P/CF can also operate stability for at least 100 *** coupling with NiFe-LDH/IF in a two-electrode system,the voltage of NiFe-LDH/IF(+)||CoRuOH/Co_(2)P/CF(-)at 1000 mA/cm^(2)is merely 1.77 v with 100 h,demonstrating great potential for water *** implementation of this work provides a new strategy and reference for the further improvement of transition metal phosphides as HER electrocatalysts.

关键词： CoRuOH/Co_(2)P/CF Enhanced activity and stability Double active site Large current density Hydrogen evolution reaction

Case Studies on Time-Dependent Ginzburg-Landau Simulations for Superconducting Applications

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Electromagnetic Science 2024年第2期2卷 1-20页

作者： Cun Xue Qing-yu Wang Han-Xi Ren An He Alejandro v.Silhanek School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China College of Science Chang’an UniversityXi’an 710064China Department of Physics Universitéde LiègeB-4000 Sart TilmanBelgium

The macroscopic electromagnetic properties of type-II superconductors are mainly influenced by the behavior of micro-scopic superconducting flux quantum ***-dependent Ginzburg-Landau(TDGL)theory is a well-known tool for describing and examining both the statics and dynamics of these superconducting *** have been instrumental in replicating and elucidat-ing numerous experimental results over the past *** paper provides a comprehensive overview of the progress in TDGL simulations,focusing on three key aspects of superconductor *** delve first into vortex rectification in supercon-ductors described within the TDGL framework,specifically highlighting the achievement of superconducting diode effect through asymmetric pinning landscapes and the reversible manipulation of vortex ratchets with dynamic pinning *** terms of the achievements of TDGL simulations concerning the critical current density of superconductors,we emphasize particularly on the optimization of pinning sites,including vortex pinning and dynamics in polycrystalline Nb3Sn with grain *** the third aspect,we concentrate on numerical modeling of vortex penetration and dynamics in superconducting radio-frequency cavities,including a discussion on superconductor-insulator-superconductor multilayer ***,we present key findings,insights,and perspectives derived from the discussed simulations.

关键词： Time-dependent Ginzburg-Landau vortex rectification Critical current density Superconducting radio-frequen-cy cavities