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Journal of Materials Science & Technology 2019年第12期35卷 2756-2760页

作者： yuchen deng Yaming Zhang Nanlong Zhang Qiang Zhi Bo Wang Jianfeng Yang State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University

High temperature physical vapor transport(HTPVT) was employed to grow polycrystalline SiC ceramics with high density and purity, induced by nano SiC particles as seeds. The obtained SiC ceramics were identified as 6 H-SiC with a mainly preferred orientation along the(0 0 0 6) plane, and an obvious refinement of grain size was demonstrated for the SiC seeds. Mean grain sizes of the obtained SiC ceramics were112 μm and 314 μm, by using the SiC seeds with the mean particle size of 50 nm and 500 nm, respectively,which were obviously smaller than that of the seed-free sample(960 μm). The samples obtained with the seeds also demonstrated enhanced flexural strength and hardness, attributing to the reduced mean grain size. Furthermore, SiC ceramics without seeds via HTPVT exhibited a high thermal conductivity of242 W·(m·K)^-1 at room temperature due to the highly preferred orientation. While the degree of preferred orientation of seed-induced samples was lower, the thermal conductivity of SiC ceramics induced by seeding still maintained at least 200 W·(m·K)^-1 at room temperature, this level was much higher than most other methods. Therefore, seed-induced method appears to be an effective way to control structures and behavior of SiC ceramics through HTPVT.

关键词： Dense silicon carbide Seed-induced Mechanical properties Thermal conductivity HTPVT

Highly active sites of low spin Fe^(Ⅱ)N_(4)species:The identification and the ORR performance

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Nano Research 2021年第1期14卷 122-130页

作者： Huizhu Cai Bingbing Chen Xiao Zhang yuchen deng Dequan Xiao Ding Ma Chuan Shi State Key Laboratory of Fine Chemicals College of Chemical EngineeringDalian University of TechnologyDalian 116024China College of Chemistry and Molecular Engineering and College of Engineering Peking UniversityBeijing 100871China Center for Integrative Materials Discovery Department of Chemistry and Chemical EngineeringUniversity of New HavenCT 06516USA

Over recent years,catalytic materials of Fe-N-C species have been recognized being active for oxygen reduction reaction(ORR).However,the identification of active site remains challenging as it generally involves a pyrolysis process and mixed components being *** Fe_(3)C/C and Fe_(2)N/C samples were synthesized by temperature programmed reduction of Fe precursors in 15%CH_(4)/H_(2)and pure NH_(3),*** acid leaching of Fe_(2)N/C sample,only single sites of FeN_(4)species were presented,providing an ideal model for identification of catalytic functions of the single sites of FeN_(4)in ORR.A correlation was conducted between the concentration of Fe^(Ⅱ)N_(4)in low spin state by Mossbauer spectra and the kinetic current density at 0.8 V in alkaline media,and such a structure-performance correlation assures the catalytic roles of low spin Fe^(Ⅱ)N_(4) species as highly active sites for the ORR.

关键词： single sites of FeN_(4) oxygen reduction reaction structure-performance correlation electrocatalysis

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明代中期江南地区造物设计中的商匠互动

南京艺术学院学报（美术与设计） 2021年第4期 30-35页

作者：邓雨晨上海大学美术学院上海200072

明中期抑商政策的赓续松懈和工匠制度的深入革新,推动了江南地区商人和工匠社会地位的擢升,促发了"商匠互动"的陡增。本文旨于分析商匠互动的社会渊源、形式、本质和局限,提出"商匠关系"实为具有资本主义性质的雇佣关系,"商匠互动"实质... 详细信息

明中期抑商政策的赓续松懈和工匠制度的深入革新,推动了江南地区商人和工匠社会地位的擢升,促发了"商匠互动"的陡增。本文旨于分析商匠互动的社会渊源、形式、本质和局限,提出"商匠关系"实为具有资本主义性质的雇佣关系,"商匠互动"实质根源于具有资本主义性质的生产,其促成资本主义萌芽发展的同时具有封建局限性。

关键词：明代中期江南地区商匠互动资本主义萌芽

ICON, a 3D-reconstruction algorithm using compressed sensing approach and its application in electron tomography

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Dextran prevents TE-induced intracellular Ca2+overload in isolated adult mouse ventricular myocytes

第四届全国冷冻电子显微学与结构生物学专题研讨会

作者： yuchen deng Yu Chen Yan Zhang Fa Zhang 孙飞 National Key Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of Sciences University of Chinese Academy of Sciences National Key Laboratory of Intelligent Information Processing Institute of Computing TechnologyChinese Academy of Sciences 中国科学院生物物理研究所

＜正＞Cryo-electron tomography（ET）plays an important role in revealing biological structures,ranging from macromolecule scale to subcellular *** acquiring series of pictures with different angular assignment,one per...

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Dextran prevents TE-induced intracellular Ca2+overload in is...

Atomically dispersed lr/α-MoC catalyst with high metal loading and thermal stability for water-promoted hydrogenation reaction

第12届生物毒素研究及医药应用学术大会

作者： Hui Zhang Qianqian Wang yuchen deng Jiawei Gu Liang Xiao Liming Zhang Department of Marine Biotechnology Faculty of Naval MedicineSecond Military Medical University Grade 2013 Naval Clinical MedicineSecond Military Medical University Grade 2013 Clinical MedicineSecond Military Medical University

Intracellular Ca overload plays a pivotal role in acute heart failure,which is induced by tentacle extract(TE) from jellyfish *** an intervention that inhibits the increase of cytosolic Cafrom both extracellular Ca entry and intracellular Ca release,it is maybe beneficial to the antagonistic effect of the cardiotoxicity of jellyfish ***,the polysaccharide,Dextran,with its large molecule weight 0 000 kDa and capacity to stabilize the cell function,might be able to prevent the TE-induced intracellular Ca overload by hindering the extracellular Ca entry,through the previously reported non-selective ion channel complex assembled by jellyfish venom in the cell *** mouse ventricular myocytes were isolated by the method collagenase II *** were loaded with Fluo-4 to indicate the Ca in *** Ca imaging was scanned by an Olympus confocal microscopy with the excitation wavelength 488 nm and emission wavelength longer than 505 *** myocytes were gradually turning shrunk,accompanied with intracellular Caincrease after TE administration within 10 *** cells were pretreated with 5 μg/ml Dextran,intracellular Ca and morphological characteristics of cells did not change within 10 min after perfusion with 30 μg/ml ***,no obvious difference was observed in control andDextran *** conclusion,5 μg/ml Dextran prevents TE-induced intracellular Ca overload in isolated mouse ventricular myocytes,which is a promising reagent to antagonize the cardiotoxicity of jellyfish venom.

关键词： Jellyfish Cyaneacapillata tentacle extract Ca2+ Dextran

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National Science Review 2022年第1期 118-127页

作者： Siwei Li Ruochen Cao Mingquan Xu yuchen deng Lili Lin Siyu Yao Xuan Liang Mi Peng Zirui Gao Yuzhen Ge Jin-Xun Liu Wei-Xue Li Wu Zhou Ding Ma Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering and College of Engineering and BIC-ESAT Peking University School of Chemistry and Materials Science CAS Excellence Center for Nanoscience Hefei National Laboratory for Physical Sciences at the Microscale iChEM University of Science and Technology of China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences School of Physical Sciences and CAS Key Laboratory of Vacuum Physics University of Chinese Academy of Sciences

Synthesis of atomically dispersed catalysts with high metal loading and thermal stability is challenging but particularly valuable for industrial application in heterogeneous ***,we report a facile synthesis of a thermally stable atomically dispersed Ir/α-MoC catalyst with metal loading as high as 4 wt%,an unusually high value for carbide supported metal *** strong interaction between Ir and theα-MoC substrate enables high dispersion of Ir on the α-MoC surface,and modulates the electronic structure of the supported Ir *** quinoline hydrogenation as a model reaction,we demonstrate that this atomically dispersed Ir/α-MoC catalyst exhibits remarkable reactivity,selectivity and stability,for which the presence of high-density isolated Ir atoms is the key to achieving high metal-normalized activity and mass-specific *** also show that the water-promoted quinoline hydrogenation mechanism is preferred over the Ir/α-MoC,and contributes to high sele ctivity towards 1,2,3,*** present work demonstrates a new strategy in constructing a high-loading atomically dispersed catalyst for the hydrogenation reaction.

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闭挤式精冲变形区力热行为及其对成形的影响

热加工工艺 2020年第21期49卷 71-75,78页

作者：牛江坡吕琳邓雨辰邓明重庆理工大学材料科学与工程学院重庆400054 重庆桌来科技公司重庆400050

为了探究闭挤式精冲变形区力学行为及温度变化对变形区塑性和成形的影响,采用有限元数值模拟分析了Al2024铝合金变形区的应力状态、摩擦、变形热对材料塑性以及成形的影响,研究了变形区温度分布以及不同工艺参数对温度的影响、不同摩擦... 详细信息

为了探究闭挤式精冲变形区力学行为及温度变化对变形区塑性和成形的影响,采用有限元数值模拟分析了Al2024铝合金变形区的应力状态、摩擦、变形热对材料塑性以及成形的影响,研究了变形区温度分布以及不同工艺参数对温度的影响、不同摩擦系数下材料应力应变状态以及对应的成形件表面光亮带比例。结果表明:闭挤式精冲时力热行为与变形区材料的塑性和精冲件质量有着密切的关系。

关键词：闭挤式精冲力热行为塑性摩擦热精冲

基于扰动状态概念的砂土-混凝土桩接触面荷载传递模型研究

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中南大学学报（自然科学版） 2024年第2期55卷 550-561页

作者：邓煜晨陈琛杨奇冷伍明徐方中南大学土木工程学院湖南长沙410075 湘潭大学土木工程学院湖南湘潭411105 中南大学重载铁路工程结构教育部重点实验室湖南长沙410075

基于扰动状态概念理论,考虑砂土密实度对扰动函数的影响,建立混凝土桩-砂土接触面荷载传递模型。用混凝土板表征桩侧粗糙度效应,采用大型直剪仪开展不同密实度的砂土-混凝土桩接触面力学行为的试验模拟,研究砂土密实度对混凝土桩-砂土... 详细信息

基于扰动状态概念理论,考虑砂土密实度对扰动函数的影响,建立混凝土桩-砂土接触面荷载传递模型。用混凝土板表征桩侧粗糙度效应,采用大型直剪仪开展不同密实度的砂土-混凝土桩接触面力学行为的试验模拟,研究砂土密实度对混凝土桩-砂土接触面的力学特性的影响规律,分析接触面模型初始剪切系数、模型扰动参数(A和Z)对桩-砂土接触面荷载传递模型的作用机制。研究结果表明:1)混凝土桩-砂土接触面易呈现应变软化,在低法向应力条件下,混凝土桩-密砂接触面的应变软化程度最大。2)模型扰动参数Z在数值上近似等于孔隙比。模型扰动参数A越大,砂土与混凝土桩接触面的软化显著程度越大。参数A随着密实度增大而增大。随着法向应力增大,密砂的扰动参数A呈近似线性衰减,松砂和中密砂的扰动参数A近似呈双折线衰减。3)初始剪切系数k_s随着法向应力增大而增大,密实度越大,增速越快。4)基于扰动状态概念的桩-砂土接触面荷载传递模型可靠、参数的物理意义明确且易确定,能很好地表征桩-砂土接触面的应变软化及硬化等力学特征。

关键词：密实度桩-砂土接触面荷载传递模型扰动状态概念

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凸台板件挤压成形中的几个问题

热加工工艺 2019年第11期48卷 95-99页

作者：吕琳公冶凡娇邓雨辰邓明重庆理工大学材料科学与工程学院重庆400054 重庆桌来科技公司重庆400050

以理论分析、数值模拟和物理实验相结合的方法,对板件凸台的精冲挤压复合工艺进行了分类,指出其各自的成形特点。研究了带凸台板件的精冲-挤压复合成形力计算公式,并通过实验对理论公式进行了验证。分析了板件凸台挤压过程中可能的成形... 详细信息

以理论分析、数值模拟和物理实验相结合的方法,对板件凸台的精冲挤压复合工艺进行了分类,指出其各自的成形特点。研究了带凸台板件的精冲-挤压复合成形力计算公式,并通过实验对理论公式进行了验证。分析了板件凸台挤压过程中可能的成形缺陷,指出了缺陷形成的原因:主要是板状挤压工况和摩擦导致材料流动的方式和流动速度不同。并论述了使用润滑油、控制挤压凸、凹模直径比值及增大挤压凹模圆角等措施来控制缺陷。

关键词：精冲-挤压复合成形成形力成形缺陷凸台

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浅埋土洞加筋路基变形的双梁模型解

武汉大学学报（工学版） 2024年第5期57卷 593-600页

作者：吴方宇陈志波邓煜晨福州大学紫金地质与矿业学院福建福州350116 地质工程福建省高校工程研究中心福建福州350116

浅埋土洞加筋路基受力机理十分复杂,为探究其变形和受力情况,将路面结构和土工格室简化为考虑抗弯刚度的有限长梁,路堤填土和路基土分别采用Kerr模型和Pasternak模型模拟,构建双梁模型,求解双梁竖向变形解析解。分别采用浅埋土洞加筋路... 详细信息

浅埋土洞加筋路基受力机理十分复杂,为探究其变形和受力情况,将路面结构和土工格室简化为考虑抗弯刚度的有限长梁,路堤填土和路基土分别采用Kerr模型和Pasternak模型模拟,构建双梁模型,求解双梁竖向变形解析解。分别采用浅埋土洞加筋路基数值模拟结果与无土洞加筋路基室内试验结果验证双梁模型解析结果的有效性,并基于解析结果分析了深宽比、土工格室抗弯刚度和路基土弹性模量对双梁竖向变形、弯矩和剪力的影响。结果表明:深宽比和路基弹性模量对浅埋土洞加筋路基土洞区域的受力与变形有显著影响,而土工格室抗弯刚度的影响能力与路基弹性模量有关,土洞宽度决定路面结构和土工格室的剪力分布特点。

关键词：加筋路基土洞双梁模型变形数值分析