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Grain-boundary segregation and grain growth in nanocrystalline substitutional solid solution alloys

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Journal of materials Science & Technology 2024年第1期168卷 239-249页

作者： Fawei Tang Chao Hou Hao Lu Zhi Zhao Xiaoyan Song Faculty of materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were described.Based on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been proposed.This study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.

关键词： Substitutional solid solution Grain boundary segregation Thermal stabilization Solute concentration Grain size

A hybrid bacterium with tumor-associated macrophage polarization for enhanced photothermal-immunotherapy

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Acta Pharmaceutica Sinica B 2022年第6期12卷 2683-2694页

作者： Jingya Zhao Huabei Huang Jinyan Zhao Xiang Xiong Sibo Zheng Xiaoqing Wei Shaobing Zhou key laboratory of advanced Technologies of materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Remodeling the tumor microenvironment through reprogramming tumor-associated macrophages(TAMs) and increasing the immunogenicity of tumors via immunogenic cell death(ICD) have been emerging as promising anticancer immunotherapy strategies.However,the heterogeneous distribution of TAMs in tumor tissues and the heterogeneity of the tumor cells make the immune activation challenging.To overcome these dilemmas,a hybrid bacterium with tumor targeting and penetration,TAM polarization,and photo thermal conversion capabilities is developed for improving antitumor immunotherapy in vivo.The hybrid bacteria(B.b@QDs) are prepared by loading Ag;S quantum dots(QDs) on the Bifidobacterium bifidum(B.b) through electrostatic interactions.The hybrid bacteria with hypoxia targeting ability can effectively accumulate and penetrate the tumor tissues,enabling the B.b to fully contact with the TAMs and mediate their polarization toward M1 phenotype to reverse the immunosuppressive tumor microenvironment.It also enables to overcome the intratumoral heterogeneity and obtain abundant tumor-associated antigens by coupling tumor penetration of the B.b with photo thermal effect of the QDs,resulting in an enhanced immune effect.This strategy that combines B.b-triggered TAM polarization and QD-induced ICD achieved a remarkable inhibition of tumor growth in orthotopic breast cancer.

关键词： Immunotherapy Tumor-associated macrophage Immunogenic cell death Bifidobacterium Quantum dot

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Wound microenvironment self-adaptive hydrogel with efficient angiogenesis for promoting diabetic wound healing

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Bioactive materials 2023年第2期20卷 561-573页

作者： Zijian Shao Tianyu Yin Jinbo Jiang Yang He Tao Xiang Shaobing Zhou key laboratory of advanced Technologies of materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu610031PR China

Neovascularization is critical to improve the diabetic microenvironment,deliver abundant nutrients to the wound and promote wound closure.However,the excess of oxidative stress impedes the healing process.Herein,a self-adaptive multifunctional hydrogel with self-healing property and injectability is fabricated through a boronic ester-based reaction between the phenylboronic acid groups of the 3-carboxyl-4-fluorophenylboronic acid-grafted quaternized chitosan and the hydroxyl groups of the polyvinyl alcohol,in which pro-angiogenic drug of desferrioxamine(DFO)is loaded in the form of gelatin microspheres(DFO@G).The boronic ester bonds of the hydrogel can self-adaptively react with hyperglycemic and hydrogen peroxide to alleviate oxidative stress and release DFO@G in the early phase of wound healing.A sustained release of DFO is then realized by responding to overexpressed matrix metalloproteinases.In a full-thickness diabetic wound model,the DFO@G loaded hydrogel accelerates angiogenesis by upregulating expression of hypoxia-inducible factor-1 and angiogenic growth factors,resulting in collagen deposition and rapid wound closure.This multifunctional hydrogel can not only self-adaptively change the microenvironment to a pro-healing state by decreasing oxidative stress,but also respond to matrix metalloproteinases to release DFO.The self-adaptive multifunctional hydrogel has a potential for treating diabetic wounds.

关键词： Wound microenvironment Self-adaptive hydrogel MMP-9 responsive Angiogenesis Diabetic wound healing

Investigation on UV-curing Reprocessable Thermosets Bearing Hindered Urea Bonds and Their Composites with Modified Zinc Oxide Nanoparticles

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Chinese Journal of Polymer Science 2024年第6期42卷 751-765页

作者： Jun-Hao Zhou Li-Ming Tang key laboratory of advanced materials of ministry of education of China Department of Chemical EngineeringTsinghua UniversityBeijing100084China

In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the reactive diluent via one-pot procedure.The prepolymers were characterized fully by various techniques.Then,their thermosets were fabricated via UV curing in presence of a photo initiator,and their mechanical property and thermal behavior were investigated and compared.Different from the none HUB containing thermoset,the HUB containing thermosets(defined as PUT)could be recycled and reprocessed by hot press under relatively mild conditions with high recovery ratio of mechanical property.Furthermore,zinc oxide(ZnO)nanoparticles were modified with 3-(trimethoxysilyl)propyl methacrylate and the modified ZnO(defined as ZnO-TPM)was dispersed and polymerized into PUT matrix to prepare their nanocomposites.The influence of ZnO-TPM on the mechanical performance of the composites was evaluated,which indicated that the Young’s modulus and tensile strength increased gradually to the maximum values at ZnO-TPM content of 1 wt%and then decreased.The composites also displayed good reprocessability with improved recovery ratio compared to the pure PUT sample.In addition,the composite materials exhibited strong UV absorption capacity,implying their potential application in the circumstance where UV-shielding was required.

关键词： Polyurethane-urea methacrylate Hindered urea bond ZnO nanoparticles Reprocessing UV curing

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Piezocatalytic performance of Fe_(2)O_(3)−Bi_(2)MoO_(6) catalyst for dye degradation

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Frontiers of Chemical Science and Engineering 2023年第6期17卷 716-725页

作者： Lili Cheng Xiaoyao Yu Danyao Huang Hao Wang Ying Wu key laboratory of the ministry of education for advanced Catalysis materials School of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua 321004China

A Fe_(2)O_(3)−Bi_(2)MoO_(6) heterojunction was synthesized via a hydrothermal method.Scanning electron microscopy,transmission electron microscopy,energy-dispersive X-ray,powder X-ray diffraction,Fourier transform infrared spectroscopy and ultra-violet−visible near-infrared spectrometry were performed to measure the structures,morphologies and optical properties of the as-prepared samples.The various factors that affected the piezocatalytic property of composite catalyst were studied.The highest rhodamine B degradation rate of 96.6%was attained on the 3% Fe_(2)O_(3)−Bi_(2)MoO_(6) composite catalyst under 60 min of ultrasonic vibration.The good piezocatalytic activity was ascribed to the formation of a hierarchical flower-shaped microsphere structure and the heterostructure between Fe_(2)O_(3) and Bi_(2)MoO_(6),which effectively separated the ultrasound-induced electron–hole pairs and suppressed their recombination.Furthermore,a potential piezoelectric catalytic dye degradation mechanism of the Fe_(2)O_(3)−Bi_(2)MoO_(6) catalyst was proposed based on the band potential and quenching effect of radical scavengers.The results demonstrated the potential of using Fe_(2)O_(3)−Bi_(2)MoO_(6) nanocomposites in piezocatalytic applications.

关键词： piezocatalysis Fe_(2)O_(3)−Bi_(2)MoO_(6) dye decomposition ultrasonic vibration

Recent Advances in High‑Efficiency Electrocatalytic Water Splitting Systems

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Electrochemical Energy Reviews 2023年第1期6卷 1-38页

作者： Xian‑Wei Lv Wen‑Wen Tian Zhong‑Yong Yuan key laboratory of advanced Energy materials Chemistry(ministry of education) School of Materials Science and EngineeringNankai UniversityTianjin 300350China

Electrocatalytic water splitting driven by renewable energy input to produce clean hydrogen(H_(2))has been widely considered a prospective approach for a future hydrogen-based society.However,the development of industrial alkaline water electrolyzers is hindered due to their unfavorable thermodynamics with high overpotential for delivering the whole process,caused by sluggish kinetics involving four-electron transfer.Further exploration of water electrolysis with low energy consumption and high efficiency is urgently required to meet the ever-growing energy storage and portfolio demands.This review emphasizes the strategies proposed thus far to pursue high-efficiency water electrolysis systems,including from the aspects of electro-catalysts(from monofunctional to bifunctional),electrode engineering(from powdery to self-supported),energy sources(from nonrenewable to renewable),electrolytes(from pure to hybrid),and cell configurations(from integrated to decoupled).Critical appraisals of the pivotal electrochemistry are highlighted to address the challenges in elevating the overall efficiency of water splitting.Finally,valuable insights for the future development directions and bottlenecks of advanced,sustainable,and high-efficiency water splitting systems are outlined.

关键词： Electrocatalytic water splitting Hydrogen-based society Electrode engineering Cell configurations Challenges and perspectives

Highly selective photocatalytic CO_(2) reduction to ethylene in pure water by Nb_(2)O_(5) nanoparticles with enriched surface –OH groups under simulated solar illumination

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先进陶瓷(英文) 2023年第8期12卷 1641-1654页

作者： Haoyu Zhang Shuang Gao Haitao Guan Weiyi Yang Qi Li key laboratory of advanced Technologies of materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Photocatalytic CO_(2) reduction to valuable chemical compounds could be a promising approach for carbon-neutral practice.In this work,a simple and robust thermal decomposition process was developed with ammonium carbonate((NH4)2CO3)as both precipitation agent and sacrificial template to produce fine Nb_(2)O_(5) nanoparticles with the rich existence of surface hydroxyl(–OH)groups.It was found by density functional theory(DFT)calculations and experiments that the rich existence of the surface–OH groups enhanced the adsorption of both reactants(CO_(2) and H_(2)O molecules)for the photocatalytic CO_(2) reduction on these fine Nb_(2)O_(5) nanoparticles,and the highly selective conversion of CO_(2) to the high-value chemical compound of ethylene(C_(2)H_(4),~68μmol·g^(−1)·h^(−1) with~100%product selectivity)was achieved under simulated solar illumination without usage of any sacrificial agents or noble metal cocatalysts.This synthesis process may also be readily applied as a surface engineering method to enrich the existence of the surface–OH groups on various metal oxide-based photocatalysts for a broad range of technical applications.

关键词： photocatalytic CO_(2)reduction niobium oxide nanoparticles thermal decomposition surface hydroxyl(-OH)groups simulated solar illumination

Effect of oxygen addition and annealing time on microstructure and mechanical properties of Ti-34Nb alloy

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Journal of Iron and Steel Research(International) 2023年第1期30卷 158-164页

作者： Jun-shuai Wang Wen-long Xiao Lei Ren Yu Fu Chao-li Ma key laboratory of Aerospace advanced materials and Performance of ministry of education School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

The effect of oxygen addition and annealing time on microstructure and mechanical properties of Ti-34Nb and Ti-34Nb-0.2O alloys was investigated.The addition of O suppresses the martensitic transformation.The phase composition changes from singleα''phase toα''+βphases with oxygen addition.The addition of oxygen increases strength significantly at as-received,cold-rolled,and annealed alloys through solid solution strengthening.The accumulation of abundance of defects and grain refinement introduced by cold rolling have a significant strengthening effect but also damage plasticity.The addition of oxygen increasesα/βtransformation temperature and promotes the precipitation ofαphase during annealing in Ti-34Nb-0.2O alloy.αprecipitates can inhibit grain growth during annealing.The strength decreases with annealing time increased due to the increase in grain size in Ti-34Nb alloy,while the strength increases in Ti-34Nb-0.2O alloy mainly due to the precipitation ofαphase.The cold rolling followed by annealing and addition of oxygen can improve the properties of alloys.

关键词： Titanium alloy Oxygen addition Annealing time αprecipitate

界面工程用于提高CoP-Co_(2)P多晶型物在全pH值析氢反应和碱性全解水反应中的电催化性能

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Science China materials 2022年第9期65卷 2433-2444页

作者：陈蕾任金涛袁忠勇 key laboratory of advanced Energy materials Chemistry(ministry of education) National Institute for Advanced MaterialsSchool of Materials Science and EngineeringNankai UniversityTianjin 300350China

开发具有丰富活性位点和高本征活性的磷化钴催化剂,用于高效且稳定的析氢反应(HER)和析氧反应(OER)具有重要意义.本工作通过精准地控制球形膦酸钴的热还原温度合理地构建了新型的碳包裹的CoP-Co_(2)P多晶型物.独特的多级孔结构和CoP-Co_... 详细信息

开发具有丰富活性位点和高本征活性的磷化钴催化剂,用于高效且稳定的析氢反应(HER)和析氧反应(OER)具有重要意义.本工作通过精准地控制球形膦酸钴的热还原温度合理地构建了新型的碳包裹的CoP-Co_(2)P多晶型物.独特的多级孔结构和CoP-Co_(2)P之间的异质界面不仅提高了活性位点的数量,而且还保证了优异的内在催化活性.所制备的催化剂展现出优异的电催化活性和稳定性(对于全pH值HER(0.5 mol L^(-1) H_(2)SO_(4):81 mV@10 mA cm^(-2);1.0 mol L^(-1) KOH:109 mV@10 mA cm^(-2);1.0 mol L^(-1) PBS:227 mV@10 mA cm^(-2))和碱性OER(1.0 mol L^(-1) KOH:1.53 V@10 mA cm^(-2))).在作为双电极电解槽中全解水反应的双功能电催化剂时,该材料可以在1.60 V的低电压下,1.0 mol L^(-1) KOH电解液中提供10 mA cm^(-2)的电流密度.本文还详细研究了CoP-Co_(2)P多晶型物在催化反应过程中的结构析出.本工作为用于各种电化学技术中的高效且价格合理的金属磷化物的设计和制备提供了一种新的方法.

关键词： cobalt phosphides polymorphs heterointerface hydrogen evolution oxygen evolution

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