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An Electron Microscopy Study of Vein-like Grain Boundary Microstructure in Nitrocarburized Low Carbon Steels

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Journal of Materials Science & Technology 2013年第7期29卷 669-672页

作者： Wanglin chen Cuilan Wu Jianghua chen Aigui He Center of High Resolution Electron Microscopy College of Materials Science and EngineeringHunan University

The coarsened grain boundaries （GBs） with vein-like morphology frequently appear in the nitrogen diffusion layer of nitrocarburized carbon steels. The electron probe X-ray microanalysis shows that such vein-like GBs are rich in nitrogen and carbon atoms. Transmission electron microscopy and scanning electron microscopy further reveal that the coarsened GBs consist of γ＇-nitrocarbide （Fe4（C,N）） and ε-nitrocarbide lamellas that are formed during nitrocarburizing due to high nitrogen concentration at GBs. It is shown that many of {111}〈112〉 micro twins exist in the γ＇-phase lamellas and thin ε-phase slices prefer to nucleate at their twin boundaries with the orientation relationship of {0001}ε//{111}γ＇. Upon growing large γ＇-Iamellas may become faceted and thin ε-Iamellas may grow thicker and become the main portions in the vein-like GBs. The microstructure evolution occurring in the vein-like GBs can be depicted as： α ＋ [N]/[C] → ＋ [C,N] →ε-nitrocarbides.

关键词： Nitrocarburizing Grain boundary γ'-Fe4(C,N) e-Nitrocarbide

Numerical investigation of the effect of geosynthetic clay liner chemical incompatibility on flow and contaminant transport through a defective composite liner

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第7期24卷 557-568页

作者： Shiyuan yaO Yuchao LI Shan TONG Guannian chen Yunmin chen MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Department of Civil EngineeringZhejiang UniversityHangzhou 310058 China School of Civil&Environmental Engineering and Geography Science Ningbo UniversityNingbo 315211China Ningbo ZCONE High-tech Co. Ltd.Ningbo 315000China

A composite liner consisting of a geomembrane(GMB)and a geosynthetic clay liner(GCL)can be compromised by inorganic contaminants because of a defective *** the composite liner with defective GMB is exposed to aggressive leachate conditions,the neglect of the chemical incompatibility of the GCL can potentially result in an underestimation of the leakage rate and flux through the composite *** paper proposed a numerical investigation on the effect of chemical incompatibility of GCL on the barrier performance of the composite liner with hole *** cases with leachate solutions having varied cation valencies and ionic strengths were analyzed,in which the hydraulic conductivity of GCL was *** the effect of the chemical incompatibility of GCL and the mechanisms were *** incompatibility of GCL resulted in significant increases in leakage rate and flux through the composite liner by factors of up to 4.9 and 5.0,*** incompatibility-affected area in GCL is located within 0.1 m from the center of the hole in the *** coupled increase in the hydraulic conductivity of GCL and pore water concentration impacts the flux and leakage in a short period of *** GCL chemical incompatibility considered,advection may dominate the contaminant transport through GCL.

关键词： Geosvnthetic clay liner(GCL) Chemical incompatibility Leakage Contaminant transport Hvdraulic conductivity

Silicalite-1 zeolite encapsulated Fe nanocatalyst for Fenton-like degradation of methylene blue

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Chinese Journal of Chemical Engineering 2023年第1期53卷 251-259页

作者： Hongwei Guo Linyuan chen Xueying Zhang Huanhao chen yan Shao State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China School of Environmental Science and Engineering Nanjing Tech UniversityNanjing 211816China

Encapsulation of Fe nanoparticles in zeolite is a promising way to significantly improve the catalytic activity and stability of Fe-based catalysts during the degradation process of organic ***,Fe nanocatalysts were encapsulated into silicalite-1(S-1)zeolite by using a ligand-protected method(with dicyandiamide(DCD)as a organic ligand)under direct hydrothermal synthesis ***-resolution transmission electron microscopy(HRTEM)results confirmed the high dispersion of Fe nanocatalysts which were successfully encapsulated within the voids among the primary particles of the S-1 *** developed S-1 zeolite encapsulated Fe nanocatalyst(Fe@S-1)exhibited significantly improved catalytic activity and reusability in the catalytic degradation process of methylene blue(MB).Specifically,the developed Fe0.021@S-1 catalyst showed high catalytic degradation activity,giving a high MB degradation efficiency of 100%in 30 min,outperformed the conventional impregnated catalyst(Fe/S-1).Moreover,the Fe@S-1 catalyst afforded an outstanding stability,showing only ca.7.9%activity loss after five cycling tests,while the Fe/S-1 catalyst presented a significantly activity loss of 50.9%after only three ***,the encapsulation strategy enabled a relatively lower Fe loading in the Fe@S-1 catalyst in comparison with that of the Fe/S-1 catalyst,i.e.,0.35%vs.0.81%(mass).Radical scavenging experiments along with electron spin resonance(ESR)measurements confirmed that the major role ofOH in the MB degradation ***,Fe@S-1 catalyst with high molar ratio of[Fe(DCD)]Cl3 is beneficial to form Fe complexes/nanoclusters in the voids(which has large pore size of 1–2 nm)among the primary particles of the zeolite,and thus improving the diffusion and accessibility of reactants to Fe active sites,and thus exhibiting a relatively higher degradation *** work demonstrates that zeolite-encapsulated Fe nanocatalysts present potential applications in the

关键词： Zeolite Encapsulation Fe nanocatalyst Degradation Methylene blue

公共文化服务背景下我国公共图书馆发展战略分析

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图书馆 2017年第11期 1-8页

作者：陈雅王锰南京大学信息管理学院南京210023 江苏大学科技信息研究所江苏镇江212013

文章阐释了处于环境变革中的公共图书馆进行战略规划的重要价值,将公共图书馆与战略管理理论结合,对公共图书馆战略规划进行定位。接着分析我国公共图书馆发展的宏观外部环境包括政治环境、经济环境、社会环境、技术环境,内部环境包括... 详细信息

文章阐释了处于环境变革中的公共图书馆进行战略规划的重要价值,将公共图书馆与战略管理理论结合,对公共图书馆战略规划进行定位。接着分析我国公共图书馆发展的宏观外部环境包括政治环境、经济环境、社会环境、技术环境,内部环境包括文献资源、服务理念等优势因素,图书馆布局、管理体制、人才素质培养等方面的劣势因素。最后从公共图书馆的使命、愿景、战略目标、资源建设等方面提出我国公共图书馆的发展战略。

关键词：公共图书馆图书馆战略规划战略环境公共文化服务

Modifying agent selection for Al-7Si alloy by Miedema model

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 131-135页

作者： Zhong-wei chen Cui-ying Ma Pei chen State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

To determine the modifying agents for Al-7Si alloys, microstructure observation and mixing enthalpy analysis using Miedema model for Al-7Si alloy with additions of different rare earth elements were performed, and the effects of rare earth elements on the modifica-tion of eutectic silicon morphology were investigated. The results of mixing enthalpy analysis show that these four rare earth elements, La, Sm, Pr, and Ce, which have the large negative mixing enthalpies with Si, can be selected as modifying agents for eutectic silicon morphology. The element with the largest negative mixing enthalpy is Ce. Furthermore, the microstructures indicate that these four elements can effec-tively modify the eutectic （α）Al-Si crystals in Al-7Si alloy, and the most effective one is also Ce. Differential scanning calorimetry （DSC） results show that the eutectic temperature depressions due to the additions of modifying agents are the important reasons for the modification of eutectic （α）Al-Si crystals.

关键词： aluminum alloys silicon alloys modifying agents rare earth elements microstructure enthalpy

模因论教学法对大学英语低级别学生产出性词汇学习的影响

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肇庆学院学报 2025年第1期46卷 66-72页

作者：陈宜黄洪志福建医科大学文理艺术学院福建福州350122

本研究探讨了基于模因论的英语教学方法对大学英语低级别学生产出性词汇学习效果的影响。研究选取两个英语低级别班级作为实验对象,随机分为实验组(n=51)和对照组(n=51)。实验组接受基于模因论的词汇教学,而对照组则采用传统教学方法。... 详细信息

本研究探讨了基于模因论的英语教学方法对大学英语低级别学生产出性词汇学习效果的影响。研究选取两个英语低级别班级作为实验对象,随机分为实验组(n=51)和对照组(n=51)。实验组接受基于模因论的词汇教学,而对照组则采用传统教学方法。研究通过前测和两次后测收集数据,使用独立样本t检验分析每次测试中两组学生在产出性词汇掌握程度上的差异。结果显示,实验组在两次后测中的词汇学习成绩均显著优于对照组,表明基于模因论的教学方法能有效提高大学英语低级别学生的产出性词汇能力。本研究为英语词汇教学,特别是针对低级别学习者的教学策略提供了新的思路和实证依据,对提升学生的英语表达能力具有一定意义。

关键词：模因论大学英语低级别学生产出性词汇

High-efficiency InGaN/AlInGaN multiple quantum wells with lattice-matched AlInGaN superlattices barrier

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Chinese Physics B 2017年第1期26卷 488-492页

作者： Feng Xu Peng chen Fu-Long Jiang ya-Yun Liu Zi-Li Xie Xiang-Qian Xiu Xue-Mei Hua Yi Shi Rong Zhang You-Liao Zheng Key Laboratory of Advanced Photonic and Electronic Materials School of Electronic Science and Engineering Nanjing University Nanjing 210093 China nanjing University Institute of Optoelectronics at yangzhou Yangzhou 225009 China

A new approach to fabricating high-quality AlInGaN film as a lattice-matched barrier layer in multiple quantum wells（MQWs） is presented. The high-quality AlInGaN film is realized by growing the AlGaN/InGaN short period superlattices through metalorganic chemical vapor deposition, and then being used as a barrier in the MQWs. The crystalline quality of the MQWs with the lattice-matched AlInGaN barrier and that of the conventional InGaN/GaN MQWs are characterized by x-ray diffraction and scanning electron microscopy. The photoluminescence（PL） properties of the InGaN/AlInGa N MQWs are investigated by varying the excitation power density and temperature through comparing with those of the InGaN/GaN MQWs. The integral PL intensity of InGaN/AlInGaN MQWs is over 3 times higher than that of InGaN/GaN MQWs at room temperature under the highest excitation power. Temperature-dependent PL further demonstrates that the internal quantum efficiency of InGaN/AlInGaN MQWs（76.1%） is much higher than that of InGaN/GaN MQWs（21%）.The improved luminescence performance of InGaN/AlInGaN MQWs can be attributed to the distinct reduction of the barrier-well lattice mismatch and the strain-induced non-radiative recombination centers.

关键词： AlInGaN superlattices MQWs photoluminescence x-ray diffraction spectrum

Tip-induced superconductivity commonly existing in the family of transition-metal dipnictides MPn_(2)

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Chinese Physics B 2021年第1期30卷 14-18页

作者： Meng-Di Zhang Sheng Xu Xing-Yuan Hou ya-Dong Gu Fan Zhang Tian-Long Xia Zhi-An Ren Gen-Fu chen Ning Hao Lei Shan Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Department of Physics Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano DevicesRenmin University of ChinaBeijing 100872China Songshan Lake Materials Laboratory Dongguan 523808China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031China Information Materials and Intelligent Sensing Laboratory of Anhui Province Institute of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University) Ministry of EducationHefei 230601China

We report the tip-induced superconductivity on the topological semimetal NbSb_(2), similar to the observation on TaAs_(2) and NbAs_(2). Belonging to the same family of MPn_(2), all these materials possess similar band structures, indicating that the tip-induced superconductivity may be closely related to their topological nature and share a common mechanism. Further analysis suggests that a bulk band should play the dominant role in such local superconductivity most likely through interface coupling. In addition, the compatibility between the induced superconductivity and tips’ ferromagnetism gives an evidence for its unconventional nature. These results provide further clues to elucidate the mechanism of the tip-induced superconductivity observed in topological materials.

关键词： tip-induced superconductivity topological mechanism

Hyperglycemic memory in diabetic cardiomyopathy

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Frontiers of Medicine 2022年第1期16卷 25-38页

作者： Jiabing Zhan chen chen Dao Wen Wang Huaping Li Division of Cardiology Department of Internal MedicineTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders Wuhan 430030China

Cardiovascular diseases account for approximately 80%of deaths among individuals with diabetes mellitus,with diabetic cardiomyopathy as the major diabetic cardiovascular *** is a symptom that abnormally activates multiple downstream pathways and contributes to cardiac hypertrophy,fibrosis,apoptosis,and other pathophysiological *** glycemic control has long been at the center of diabetes therapy,multicenter randomized clinical studies have revealed that intensive glycemic control fails to reduce heart failure-associated hospitalization and mortality in patients with *** finding indicates that hyperglycemic stress persists in the cardiovascular system of patients with diabetes even if blood glucose level is tightly controlled to the normal *** process is now referred to as hyperglycemic memory(HGM)*** briefly reviewed herein the current advances that have been achieved in research on the underlying mechanisms of HGM in diabetic cardiomyopathy.

关键词： diabetes diabetic cardiomyopathy hyperglycemic memory