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Achieving high mechanical properties and corrosion resistance of Al-Zn-Mg matrix composites via regulating intragranular reinforcements

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Journal of Materials Science & Technology 2023年第22期153卷 1-7页

作者： xudong rong Yue Li Xiaofeng Chen Xiang Zhang Dongdong Zhao Chunnian He Chunsheng Shi Naiqin Zhao Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou 350207China School of Materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional Materials Tianjin UniversityTianjin 300350China Collaborative Innovation Center of Chemical Science and Engineering Tianjin 300072China

1.Introduction Driven by the engineering application of transportation and aerospace,simultaneously achieving excellent mechanical properties and corrosion resistance are urgently required for the next-generation Al m... 详细信息

关键词： corrosion resistance composites

Si-Assisted Solidification Path and Microstructure Control of 7075 Aluminum Alloy with Improved Mechanical Properties by Selective Laser Melting

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Acta Metallurgica Sinica(English Letters) 2022年第9期35卷 1424-1438页

作者： Junwei Sha Meixian Li Lizhuang Yang xudong rong Bowen Pu Dongdong Zhao Simi Sui Xiang Zhang Chunnian He Jianglin Lan Naiqin Zhao School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials Tianjin UniversityTianjin300350China Collaborative Innovation Center of Chemical Science and Engineering Tianjin300350China Key Laboratory of Advanced Ceramics and Machining Technology Ministry of EducationTianjin300350China Central Iron and Steel Research Institute(CISRI) Beijing100081China

The construction and application of traditional high-strength 7075 aluminum alloy(Al7075) through selective laser melting(SLM) are currently restricted by the serious hot cracking phenomenon. To address this critical issue, in this study, Si is employed to assist the SLM printing of high-strength Al7075. The laser energy density during SLM is optimized, and the eff ects of Si element on solidification path, relative density, microstructure and mechanical properties of Al7075 alloy are studied systematically. With the modified solidification path, laser energy density, and the dense microstructure with refined grain size and semi-continuous precipitates network at grain boundaries, which consists of fine Si, β-MgSi, Q-phase and θ-AlCu, the hot cracking phenomenon and mechanical properties are eff ectively improved. As a result, the tensile strength of the SLM-processed Si-modified Al7075 can reach 486 ± 3 MPa, with a high relative density of ~ 99.4%, a yield strength of 291 ± 8 MPa, fracture elongation of(6.4 ± 0.4)% and hardness of 162 ± 2(HV) at the laser energy density of 112.5 J/mm~3. The main strengthening mechanism with Si modification is demonstrated to be the synergetic enhancement of grain refinement, solution strengthening, load transfer, and dislocation strengthening. This work will inspire more new design of high-strength alloys through SLM.

关键词： Selective laser melting(SLM) 7075 aluminum alloy High-strength alloy Microstructure control Solidification path

Regulating the conductance of tungsten diselenide by oxygen plasma and improving its electrical stability by encapsulation

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Nano Research 2024年第4期17卷 3253-3260页

作者： Zhaofang Cheng Shaodan He Shimin Zhang Shijun Duan Min Wang Ziyu Liu rong Zhang Wenya Qiang xudong Zhang Minggang Xia MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter School of PhysicsXi’an Jiaotong UniversityXi’an 710049China Department of Applied Physics School of PhysicsXi’an Jiaotong UniversityXi’an 710049China Shaanxi Province Key Laboratory of Quantum Information and Optoelectronic Quantum Devices School of PhysicsXi’an Jiaotong UniversityXi’an 710049China

Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-based field-effect transistors(FETs),the modification of surface properties is essential.In this study,the seamless structural phase transition in WSe_(2) lattice is achieved by soft oxygen plasma,regulating the electrical conductance of WSe_(2)-based FETs.We found that during the soft oxygen plasma treatment with optimal processing time,the generated oxygen ions can substitute some selenium atoms and thus locally modify the bond length,inducing 2H→1T phase transition in WSe_(2) with seamless interfaces.The mosaic structures have been proven to tailor the electronic structure and increase the hole carrier concentration inside WSe_(2),significantly increasing the channel conductance of WSe_(2) FETs.With the further increase of the oxygen plasma treatment time,the creation of more selenium vacancy defects leads to the electronic doping,resulting in the reduction of conductance.Benefiting from the hexagonal boron nitride(h-BN)encapsulation to interrupt the partial structural relaxation from 1T to 2H phase,our WSe_(2) FET exhibits high electronic stability with conductance of 6.8×10^(-4) S,which is about four orders of magnitude higher than 2H WSe_(2)(5.8×10^(-8) S).This study could further broaden the WSe_(2) FETs in applications for functionalization and integration in electronics.

关键词： tungsten selenide(WSe2) structural phase transition oxygen plasma conductance hexagonal boron nitride(h-BN)encapsulation

Fibroblast-localized lncRNA CFIRL promotes cardiac fibrosis and dysfunction in dilated cardiomyopathy

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Science China(Life Sciences) 2024年第6期67卷 1155-1169页

作者： Shuai Yuan xudong Zhang Jiabing Zhan rong Xie Jiahui Fan Beibei Dai Yanru Zhao Zhongwei Yin Qian Liu Dao Wen Wang Huaping Li Chen Chen Division of Cardiology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders Wuhan 430030China Department of Forensic Medicine Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

CFIRL is a long noncoding RNA(lnc RNA),we previously identified as the most significantly upregulated lnc RNA in the failing hearts of patients with dilated cardiomyopathy(DCM).In this study,we determined the function of CFIRL and its role in DCM.Real-time polymerase chain reaction and in situ hybridization assays revealed that CFIRL was primarily localized in the nucleus of cardiac fibroblasts and robustly increased in failing hearts.Global knockdown or fibroblast-specific knockout of CFIRL attenuated transverse aortic constriction(TAC)-induced cardiac dysfunction and fibrosis in vivo.Overexpression of CFIRL in vitro promoted fibroblast proliferation and aggravated angiotensin II-induced differentiation to myofibroblasts.CFIRL knockdown attenuated these effects.Mechanistically,RNA pull-down assay and gene expression profiling revealed that CFIRL recruited ENO1,a newly identified noncanonical transcriptional factor,to activate IL-6transcription.IL-6 exerted a paracrine effect on cardiomyocytes to promote cardiac hypertrophy,which can be prevented by CFIRL knockdown.These findings uncover the critical role of CFIRL,a fibroblast-associated lnc RNA,in heart failure by facilitating crosstalk between fibroblasts and cardiomyocytes.CFIRL knockdown might be a potent strategy to prevent cardiac remodeling in heart failure,particularly in DCM.

关键词： lncRNA fibroblast fibrosis dilated cardiomyopathy heart failure

节段拼装变截面波形钢腹板连续组合箱梁的剪切性能试验研究

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湖南大学学报（自然科学版） 2024年第3期51卷 170-181页

作者：赵品邵旭东荣学亮刘鑫道路与铁道工程安全保障省部共建教育部重点实验室(石家庄铁道大学) 河北石家庄050043 石家庄铁道大学土木工程学院河北石家庄050043 湖南大学土木工程学院湖南长沙410082 河北自贸区汉曹铁路有限公司河北唐山063200

为了研究节段预制拼装波形钢腹板连续组合箱梁的抗剪性能,制作两片缩尺试验梁,包括节段拼装变截面波形钢腹板连续箱梁和相同尺寸的整体浇筑变截面波形钢腹板连续箱梁.通过静力试验和数值分析,得到了节段拼装梁的剪应力分布规律、波形钢... 详细信息

为了研究节段预制拼装波形钢腹板连续组合箱梁的抗剪性能,制作两片缩尺试验梁,包括节段拼装变截面波形钢腹板连续箱梁和相同尺寸的整体浇筑变截面波形钢腹板连续箱梁.通过静力试验和数值分析,得到了节段拼装梁的剪应力分布规律、波形钢腹板承剪比例等.结果表明:在中跨对称加载作用下,中跨1/4位置处节段拼装梁与整体梁波形钢腹板的剪应力沿梁高方向均匀分布,节段拼装梁的剪应力值要大于整体梁的相应值.推导出节段拼装变截面波形钢腹板组合箱梁的剪应力计算公式,并考虑施工工艺对剪应力的影响,通过与实测值对比验证公式的准确性.两片试验梁的波形钢腹板的承剪比受荷载影响较小,保持一个恒定的比例;两片试验梁在中支座位置处的钢腹板承剪比均为50%,并沿着试验梁纵向方向向两侧不断增大;在中跨1/4位置,节段拼装梁钢腹板的承剪比达到85%以上,整体梁的钢腹板在该位置的承剪比在75%左右,两片试验梁在边跨相应位置承剪比相差不大.将适用于节段拼装混凝土箱梁的AASHTO接缝抗剪强度计算公式乘0.9可用于接缝截面抗剪承载力计算;上述公式值与试验值、有限元结果的误差在5%左右,可以较好地预测钢混组合结构胶接缝的抗剪强度.

关键词：桥梁工程节段拼装剪切性能室内试验变截面波形钢腹板抗剪承载力

职前教师社会情感能力的现状及影响因素——基于我国45所高校8483名职前教师的调查

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国家教育行政学院学报 2024年第5期317卷 85-95页

作者：郭绒朱旭东杭州师范大学浙江杭州311121 北京师范大学北京100875

职前教师社会情感能力是关涉职前教师全面发展、应对未来工作复杂挑战、维持职业幸福感以及培育学生社会情感能力的关键能力,它对回应全球教师教育新重点、落实党和国家关于“建设高素质教师队伍”“促进人的全面发展”等政策要求至关... 详细信息

职前教师社会情感能力是关涉职前教师全面发展、应对未来工作复杂挑战、维持职业幸福感以及培育学生社会情感能力的关键能力,它对回应全球教师教育新重点、落实党和国家关于“建设高素质教师队伍”“促进人的全面发展”等政策要求至关重要。调查我国45所高校的8483名职前教师发现:我国职前教师社会情感能力总体水平中等偏上,但能力结构失衡、专业关系建设力较弱,尤其是他人意识较弱;群体差异明显,从教意愿低、性格内向、社会实践经历欠缺、家庭氛围冷淡、学前和小学教育专业、专业综合成绩低(班级后20%)、教育实践天数短(30天及以下)的职前教师社会情感能力相对较低。从教意愿、性格倾向、家庭情感氛围、教育实践天数均正向影响职前教师社会情感能力,但前三者影响效应更大。为促进职前教师社会情感能力发展,建议健全教师教育政策法规和制度标准、建设教师社会情感能力培育课程、为职前教师提供“情感-实践-专业”三重支持。

关键词：职前教师社会情感能力调查研究教师教育质量教师质量

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“界面素化”策略改善铝基复合材料腐蚀性能

Science China Materials 2023年第11期66卷 4295-4305页

作者：戎旭东李乐陈小丰张翔赵冬冬何春年赵乃勤 School of Materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional Materials Tianjin UniversityTianjin 300350China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China

添加增强相可以提高铝基复合材料的力学性能,但同时也会促进界面上原电池网络的形成,从而提升铝基复合材料的腐蚀敏感性.因此,优化界面结构是改善复合材料耐腐蚀性能的重要途径.对此,我们提出固相铝热反应结合热处理的策略,在Al-CuO复... 详细信息

添加增强相可以提高铝基复合材料的力学性能,但同时也会促进界面上原电池网络的形成,从而提升铝基复合材料的腐蚀敏感性.因此,优化界面结构是改善复合材料耐腐蚀性能的重要途径.对此,我们提出固相铝热反应结合热处理的策略,在Al-CuO复合材料中构建包括晶界和增强体-基体界面在内的“素化界面”.本文通过浸渍/电化学腐蚀试验和微观结构表征系统研究了复合材料的晶间腐蚀行为和应力腐蚀开裂敏感性,强调了晶内分布纳米第二相(Al_(2)O_(3)增强相和Al-Cu沉淀相)对消除沿晶界连续原电池网络和阻断腐蚀路径的贡献.此外,研究发现具有低应变能且紧密结合的Al_(2)O_(3)-Al界面显著降低了局部腐蚀敏感性.这项工作阐明了复合材料界面特性与腐蚀机制之间的相关性,为发展耐腐蚀复合材料提供了新思路.

关键词： interface Al matrix composite intragranular dis-tribution corrosion mechanism

基于网络药理学和分子对接法分析5种中药活性成分治疗心肌缺血再灌注损伤的机制

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辽宁中医杂志 2024年第6期51卷 5-10,I0003-I0005页

作者：戎嘉诚洪俊黄磊陈旭东宁波市杭州湾医院浙江宁波315000

目的利用网络药理学和分子对接法的分析技术,预测大黄素、木香烃内酯、水甘草碱、表儿茶素没食子酸酯、冬凌草甲素等中药活性成分治疗心肌缺血再灌注损伤的作用机制。方法使用中药系统药理数据库和分析平台(Traditional Chinese Medicin... 详细信息

目的利用网络药理学和分子对接法的分析技术,预测大黄素、木香烃内酯、水甘草碱、表儿茶素没食子酸酯、冬凌草甲素等中药活性成分治疗心肌缺血再灌注损伤的作用机制。方法使用中药系统药理数据库和分析平台(Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,TCMSP)、HERB和SwissTargetPrediction数据库寻找5种药物活性成分的作用靶点,并通过Genecards数据库寻找心肌缺血再灌注损伤的疾病靶点,两组靶点相交得到5种活性成分针对于心肌缺血再灌注损伤的潜在治疗靶点组合。接着对上述靶点合集进行功能富集(采用R语言程序,“ClusterProfiler”包),并进一步分析,随后构建活性成分、靶点、通路、疾病和富集结果间的多种关系网络,使用Cytoscape进行美化。使用String数据库和Cytoscape软件构建靶点蛋白互作网络(protein-protein interaction networks,PPI)集合,并利用Cytoscape的CytoHubba功能筛选关键(hub)靶基因。使用PyMOL和Autodock软件进行分子对接和结果可视化及美化。结果5种活性成分治疗心肌缺血再灌注损伤的潜在作用靶点共有51个,我们发现在整体的蛋白互作网络中排名前5位的关键基因分别为编码丝氨酸/苏氨酸蛋白激酶1(Akt serine/threonine kinase 1,AKT1)、白细胞介素1β(interleukin-1β,IL-1β)、半胱天冬酶3(Caspase 3,CASP3)、血管内皮生长因子A(vascular endothelial growth factor A,VEGFA)、信号转导子和转录激活子3(signal transolucer and activator of transcription 3,STAT3),它们涉及基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)相关富集通路74条、基因本体论(gene ontology,GO)生物过程富集条目1007条、GO细胞功能富集条目39条。随后的分子对接结果发现,这5种活性成分各自与关键基因中的一种或多种结合较好。结论大黄素、木香烃内酯、水甘草碱、表儿茶素没食子酸酯、冬凌草甲素5种中草药药物活性成分可能主要通过AKT1、IL-1β、CASP3、VEGFA、STAT3等靶点作用于多种通路来发挥治疗心肌缺血再灌注损伤的作用。

关键词：中草药大黄素木香烃内酯水甘草碱表儿茶素没食子酸酯冬凌草甲素心肌缺血再灌注损伤网络药理学分子对接

超临界CO_(2)辅助热塑性聚氨酯/热塑性聚酯弹性体的发泡及其回弹特性

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高分子材料科学与工程 2024年第2期40卷 74-82页

作者：周梓傲唐文卓刘清亭张荣付旭东胡圣飞湖北工业大学绿色轻工材料湖北省重点实验室新材料与绿色制造人才引进创新示范基地湖北武汉430068

为克服热塑性聚氨酯(TPU)发泡后,其发泡材料回弹性不足、压缩强度低及收缩率大等问题,采用热塑性聚酯弹性体(TPEE)改性TPU,并以超临界CO_(2)为发泡剂,制备了TPU/TPEE发泡材料。研究了TPU/TPEE共混物的熔融及结晶行为、流变性能以及TPEE... 详细信息

为克服热塑性聚氨酯(TPU)发泡后,其发泡材料回弹性不足、压缩强度低及收缩率大等问题,采用热塑性聚酯弹性体(TPEE)改性TPU,并以超临界CO_(2)为发泡剂,制备了TPU/TPEE发泡材料。研究了TPU/TPEE共混物的熔融及结晶行为、流变性能以及TPEE含量对TPU/TPEE发泡材料循环压缩性能、回弹性能、压缩永久变形及发泡性能的影响。差示扫描量热仪与落球回弹、压缩永久形变结果表明,TPEE的加入能使TPU分子链排列的有序性降低,回弹性提高;旋转流变仪结果表明,TPEE的引入可以有效改善共混物熔体的黏弹性,使得弹性作为主导,并显著改善发泡性能;循环压缩结果表明,加入TPEE可以进一步改善泡沫的压缩性能。当添加TPEE的质量分数为7%时,TPU/TPEE发泡体相对于纯TPU泡沫,发泡体落球回弹性提高了7.25%、压缩永久变形值降低了2.84%、压缩强度提高了326%。

关键词：热塑性聚氨酯热塑性聚酯弹性体超临界CO_(2) 发泡材料