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Hierarchical porous(Ta_(0.2)Nb_(0.2)Ti_(0.2)Zr_(0.2)Hf_(0.2))C high-entropy ceramics prepared by a self-foaming method for thermal insulation

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Journal of Advanced Ceramics 2024年第7期13卷 956-966页

作者： cuiyan li Ruinan Gao Haibo Ouyang Tianzhan Shen Zihao Chen Yanlei li Key Laboratory for Green Manufacturing&Functional Application of Inorganic Materials School of Materials Science and EngineeringShaanxi University of Science and TechnologyXi’an 710021China

To meet the emerging demands for thermal protection materials for hypersonic aircraft,developing porous ultrahigh-temperature ceramics with both robust mechanical properties and superior thermal insulation performance is a critical ***,we report novel porous(Ta_(0.2)Nb_(0.2)Ti_(0.2)Zr_(0.2)Hf_(0.2))C high-entropy carbide(PHEC)ceramics fabricated by a self-foaming method using commercially available metal chloride and furfuryl alcohol(FA)as *** PHEC ceramics are constructed of microspheres with a size of 2µm,leading to a high porosity of 91.3%and an interconnected *** microspheres consist of high-entropy carbide grains(20 nm),resulting in abundant interfaces and nanosized pores in the PHEC *** to its unique hierarchical structure,the prepared PHEC ceramics have outstanding compressive strength(28.1±2 MPa)and exceptionally low thermal conductivity(κ_(T),0.046 W·m^(-1)·K^(-1))at room *** makes it a promising thermal insulation materials for ultrahigh temperature *** work provides a cost-effective and facile strategy for producing porous ultrahigh-temperature ceramics.

关键词： porous ceramics high-entropy carbides hierarchical structure thermal insulation self-foaming

Stable Thiophene-sulfur Covalent Organic Frameworks for Oxygen Reduction Reaction(ORR)

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Chemical Research in Chinese Universities 2022年第2期38卷 396-401页

作者： CHANG Shunkai li cuiyan li Hui ZHU liangkui FANG Qianrong State Key Laboratory of Inorganic Synthesis&Preparative Chemistry Jilin UniversityChangchun 130012P.R.China

Exploring novel materials deriving from earth resources to substitute for platinum(Pt) electrocatalyst to promote oxygen reduction reaction(ORR) of fuel cell cathode is very important. Herein, we have exploited two crystallographic thiophene-sulfur covalent organic frameworks(COFs), termed JUC-607 and JUC-608, as electrocatalysts that exhibited good ORR performances. These thiophene-sulfur COFs exhibited high stability, and their functional groups acting as active centers in the ORR can be precisely determined. Notably, due to a larger aperture for mass transfer and electrons transport, JUC-608 displayed a growing electrochemical performance, leading to a better ORR activity. Thus, this study will provide a new strategy for designing heteroatom-based COF materials for high-performance electrochemical catalysis.

关键词： Covalent organic framework(COF) Oxygen reduction reaction Thiophene-sulfur

A Nitrogen, Sulfur co-Doped Porphyrin-based Covalent Organic Framework as an Efficient Catalyst for Oxygen Reduction

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Chemical Research in Chinese Universities 2022年第1期38卷 167-172页

作者： YU Xiaoming MA Yunchao li cuiyan GUAN Xinyu FANG Qianrong QIU Shilun State Key Laboratory of Inorganic Synthesis&Preparative Chemistry Jilin UniversityChangchun 130012P.R.China Key Laboratory of Preparation and Application of Environmental Friendly Materials Ministry of Education Jilin Normal UniversityChangchun 130103P.R.China

Oxygen reduction reaction(ORR) is a significant reaction for energy conversion systems(such as fuel cells, metal-air batteries, etc.). It is an urgent need to develop cheap, durable and highly-active catalysts for efficient ORR. Hence, we report a metal-free nitrogen and sulfur co-doped porphyrin-based covalent organic framework(COF) as a high-efficiency ORR catalyst[the onset potential(Eo) is 0.79 V and the half-wave potential(E1/2) is 0.70 V]. The double doping of N and S atoms causes uneven charge distribution around carbon atoms, which can act as catalytic active centers, improving ORR activity. Compared with single-atom doping, double atoms doping exhibits a higher activity due to the synergistic effect between different elements. These results demonstrate that reasonable design of stable metal-free COFs with a high electrochemical activity can promote their wide applications.

关键词： Covalent organic framework(COF) Oxygen reduction reaction co-Doped material

Quasi-Three-Dimensional Cyclotriphosphazene-Based Covalent Organic Framework Nanosheet for Efficient Oxygen Reduction

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Nano-Micro Letters 2023年第9期15卷 550-561页

作者： Jianhong Chang cuiyan li Xiaoxia Wang Daohao li Jie Zhang Xiaoming Yu Hui li Xiangdong Yao Valentin Valtchev Shilun Qiu Qianrong Fang State Key Laboratory of Inorganic Synthesis and Preparative Chemistry Jilin UniversityChangchun 130012People’s Republic of China State Key Laboratory of Bio-Fibers and Eco-Textiles College of Materials Science and EngineeringQingdao UniversityQingdao 266071People’s Republic of China Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences189 Song Ling RdQingdao 266101ShandongPeople’s Republic of China Laboratoire Catalyse et Spectrochimie CNRSENSICAENUNICAENNormandie Univ6 Marechal Juin14050 CaenFrance

Metal-free carbon-based materials are considered as promising oxygen reduction reaction(ORR)electrocatalysts for clean energy conversion,and their highly dense and exposed carbon active sites are crucial for efficient *** this work,two unique quasi-three-dimensional cyclotriphosphazene-based covalent organic frameworks(Q3CTP-COFs)and their nanosheets were successfully synthesized and applied as ORR *** abundant electrophilic structure in Q3CTP-COFs induces a high density of carbon active sites,and the unique bilayer stacking of[6+3]imine-linked backbone facilitates the exposure of active carbon sites and accelerates mass diffusion during *** particular,bulk Q3CTP-COFs can be easily exfoliated into thin COF nanosheets(NSs)due to the weak interlayerπ-πinteractions.Q3CTP-COF NSs exhibit highly efficient ORR catalytic activity(half-wave potential of 0.72 V *** in alkaline electrolyte),which is one of the best COF-based ORR electrocatalysts reported so ***,Q3CTP-COF NSs can serve as a promising cathode for Zn-air batteries(delivered power density of 156 mW cm-2 at 300 mA cm^(-2)).This judicious design and accurate synthesis of such COFs with highly dense and exposed active sites and their nanosheets will promote the development of metal-free carbon-based electrocatalysts.

关键词： Covalent organic framework Quasi-three-dimensional structures Oxygen reduction reaction Metal-free electrocatalyst

1939～1940年知识界关于“宪政与抗战”的讨论及其价值体现

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抗日战争研究 2006年第4期 84-103页

作者：李翠艳河北省社会科学院历史研究所

抗战全面爆发两年后,国统区发生了第一次宪政运动的浪潮。关注中国命运的知识界站在这个潮头,应时开展了关于宪政与抗战的讨论,想借此引起民众对宪政的认识,并将宪政的理论转化为救亡图存的工具。本文对这一讨论过程作了较为详细的阐述... 详细信息

抗战全面爆发两年后,国统区发生了第一次宪政运动的浪潮。关注中国命运的知识界站在这个潮头,应时开展了关于宪政与抗战的讨论,想借此引起民众对宪政的认识,并将宪政的理论转化为救亡图存的工具。本文对这一讨论过程作了较为详细的阐述,客观评价了正、反两类观点,同时对这次讨论的价值体现作了分析。

关键词：抗战时期知识界宪政抗战

Surgical treatment of myasthenia gravis

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吉林大学学报(医学版) 1993年第6期 562-564页

作者： Zhang Zhenhe. Ji Zhendong, Hao Xingjia. li Zhijun,Fu Qiang, Tong Ti, Cui Yongsheng. li cuiyan (Department of Thoracic Surgery, First Teaching Hospital)

From March 1966 to July 1991, 63 patients with myasthenia gravis (MG) were treated surgically. Age of the patients ranged from 2 to 64 years. Pathological diagnosis of resected thymus in 63 patients with MG was as follows; tumor (27), hyperplasia (27), hypoplasia (5), tuberculosis (1), no abnormality found in thymus (3). Forty-five patients were followed-up from 5 months to 23 years. Seventeen patients showed remission, nineteen improved, three unchanged, and eight died. From the results in this series, we considered that a small tumor in the thymus cannot always be found by chest roentgenography or CT scanning, and thymectomy is still the effective treatment for MG, regardless of age of the patient or type of thymic pathology

关键词： myasthenia gravis/SU thymus/SU thymoma/SU

基于Wiki的高校知识共享平台的实现及应用研究

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图书馆学研究（应用版） 2011年第7期 71-73页

作者：李翠艳武警石家庄指挥学院

MediaWiki是一款用PHP开发的免费wiki开源包,功能强大且配制管理简单,很适合用来构建高校的知识共享平台。图书馆具有硬件和软件方面的优势,可以承担知识共享平台的构建和管理工作。基于Wiki的知识共享平台可以给知识库的构建、新型参... 详细信息

MediaWiki是一款用PHP开发的免费wiki开源包,功能强大且配制管理简单,很适合用来构建高校的知识共享平台。图书馆具有硬件和软件方面的优势,可以承担知识共享平台的构建和管理工作。基于Wiki的知识共享平台可以给知识库的构建、新型参考咨询服务、科研团队的管理、资源的共享以及基于问题的学习提供良好的支撑。

关键词： Wiki 知识共享平台 MediaWiki 应用模式

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HfC改性炭／炭复合材料的烧蚀性能

稀有金属材料与工程 2006年第A02期35卷 365-368页

作者：李翠艳李克智欧阳海波李贺军西北工业大学陕西西安710072

采用金属盐溶液浸渍-TCVI(Thermal Gradient Chemical Vapor Infiltration)法制备了HfC改性炭／炭复合材料。通过氧-乙炔烧蚀实验测试了不同含量HfC改性炭／炭复合材料的抗烧蚀性能;利用DSC-TG,SEM,XRD分析了HfC的形成过程、材料烧蚀前... 详细信息

采用金属盐溶液浸渍-TCVI(Thermal Gradient Chemical Vapor Infiltration)法制备了HfC改性炭／炭复合材料。通过氧-乙炔烧蚀实验测试了不同含量HfC改性炭／炭复合材料的抗烧蚀性能;利用DSC-TG,SEM,XRD分析了HfC的形成过程、材料烧蚀前后的微观形貌及物相组成。结果表明:HfC的加入降低了炭／炭复合材料的线烧蚀率,其中HfC含量为6．5％(质量分数,下同)的炭／炭复合材料的线烧蚀率最低。HfC具有抑制氧化及弥补缺陷的作用,从而降低了炭／炭复合材料的热化学烧蚀和机械剥蚀。

关键词：炭/炭复合材料烧蚀 HfC 微观形貌

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炭布/树脂复合摩擦材料的湿式摩擦学性能

复合材料学报 2013年第3期30卷 70-75页

作者：费杰黄剑锋曹丽云李翠艳陕西科技大学材料科学与工程学院西安710021

基于炭布优异的摩擦磨损性能、自润滑性能以及低密度等特点,将其应用于湿式摩擦材料中,以适应高转速、大压力或润滑不充分等极端工况。分别以1K、3K和6K碳布为增强体,制备出三种炭布/树脂复合摩擦材料,研究了其湿式摩擦学性能。结果表明... 详细信息

基于炭布优异的摩擦磨损性能、自润滑性能以及低密度等特点,将其应用于湿式摩擦材料中,以适应高转速、大压力或润滑不充分等极端工况。分别以1K、3K和6K碳布为增强体,制备出三种炭布/树脂复合摩擦材料,研究了其湿式摩擦学性能。结果表明:随着纤维束内单丝数量的增加,摩擦材料的瞬时制动稳定性降低,动摩擦系数减小,但是耐磨性能提高。所有摩擦材料的磨损率小于1.10×10-5 mm3/J,表现出较好的耐磨性能,并且对偶材料的磨损率很小,仅为0.40×10-5 mm3/J。磨损主要表现为纤维断裂、拔出及树脂脱粘等形式,但是在磨损表面没有形成大尺寸磨屑和明显的"第三体"磨粒,导致摩擦材料和对偶材料的磨损率较小。

关键词：湿式摩擦材料炭布摩擦系数摩擦稳定性磨损率