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ZrC-ZrB_2-SiC ceramic nanocomposites derived from a novel single-source precursor with high ceramic yield

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Journal of Advanced Ceramics 2019年第1期8卷 112-120页

作者： Zhaoju YU xuan lv Shuyi LAI Le YANG Wenjing LEI Xingang LUAN Ralf RIEDEL College of Materials Key Laboratory of High Performance Ceramic Fibers (Xiamen University) Ministry of Education College of Materials Fujian Key Laboratory of Advanced Materials (Xiamen University) College of Materials Science and Engineering Huaqiao University Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical University Technische Universit?t Darmstadt Institut für Materialwissenschaft

For the first time, ZrC-ZrB_2-SiC ceramic nanocomposites were successfully prepared by a single-source-precursor route, with allylhydridopolycarbosilane(AHPCS),triethylamine borane(TEAB),and bis(cyclopentadienyl) zirconium dichloride(Cp_2 ZrCl_2) as starting materials. The polymer-to-ceramic transformation and thermal behavior of obtained single-source precursor were characterized by means of Fourier transform infrared spectroscopy(FT-IR) and thermal gravimetric analysis(TGA). The results show that the precursor possesses a high ceramic yield about 85% at 1000 ℃.The phase composition and microstructure of formed ZrC-ZrB_2-SiC ceramics were investigated by means of X-ray diffraction(XRD) and high resolution transmission electron microscopy(HRTEM).Meanwhile, the weight loss and chemical composition of the resultant ZrC-ZrB_2-SiC nanocomposites were investigated after annealing at high temperature up to 1800 ℃. High temperature behavior with respect to decomposition as well as crystallization shows a promising high temperature stability of the formed ZrC-ZrB_2-SiC nanocomposites.

关键词： polymer derived ceramics single-source precursor ceramic nanocomposite

Experimental Study of Mooring Type Effect on the Hydrodynamic Characteristics of VLFS

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China Ocean Engineering 2022年第1期36卷 155-166页

作者： FENG Ming-wei SUN Zhao-chen LIANG Shu-xiu LI Zhi lv xuan JIA Song-lin HUXin-yue State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

Mooring system is a significant part of very large offshore floating structures(VLFS).In this paper,a single module pontoon type VLFS model considering four mooring types is studied through physical model tests to determine the effects of mooring conditions on the hydroelastic response,mooring force,incident coefficient,reflection coefficient and energy dissipation *** mooring cables are symmetrically arranged on both sides of the *** floating body model satisfies the similarity of stiffness and gravity,while the cable satisfies the similarity of elasticity and *** results show that the effect of mooring type on mooring force is greater than that on hydroelastic *** the initial tension of the mooring cable will reduce the amplitude of the leeward of the VLFS *** mooring angle of the mooring cable will affect the maximum mooring force and the initial tension of the mooring line will affect the wave period in which the maximum mooring force *** transmission coefficient and wave energy dissipation coefficient will change regularly with different mooring *** results may provide a reference to facilitate the mooring design of VLFS.

关键词： VLFS hydroelastic response mooring system 3D experimental test mooring force wave reflection coefficient wave transmission coefficient wave dissipation coefficient

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镍修饰WO_3膜光电化学氧化水的研究

分子催化 2014年第4期28卷 351-358页

作者：李振吕功煊中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室甘肃兰州730000 中国科学院大学北京100049

在强碱性溶液中低电压低电流条件下在W基底上经阳极氧化得到致密WO3层,而后在酸性条件下在WO3表面经光辅助电化学还原沉积镍,所获得的复合电极具有优异的光电化学氧化水的活性和稳定性.SEM,EDX,XPS和TEM等表征表明复合电极中具有体心立... 详细信息

在强碱性溶液中低电压低电流条件下在W基底上经阳极氧化得到致密WO3层,而后在酸性条件下在WO3表面经光辅助电化学还原沉积镍,所获得的复合电极具有优异的光电化学氧化水的活性和稳定性.SEM,EDX,XPS和TEM等表征表明复合电极中具有体心立方结构的W基底经阳极氧化形成了具有单斜结构的WO3层,表面修饰的镍物种以Ni(OH)2形式存在.光电化学实验表明WO3层对可见光具有良好的光响应,表面修饰镍后,光电氧化水的起始电位显著降低,电极的稳定性也得以提高.

关键词：光电分解水 WO3 镍修饰复合电极

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多孔硅形成过程中的晶态转变

硅酸盐学报 2017年第1期45卷 78-82页

作者：吕京美程璇北京理工大学珠海学院材料与环境学院广东珠海519088 厦门大学材料学院材料科学与工程系福建厦门361005 福建省特种先进材料重点实验室福建厦门361005

采用电化学阳极氧化法,对p型单晶硅施加30 mA/cm^2的恒定电流密度,在40%氢氟酸溶液中和氮气保护气氛下分别极化1、3和5 min,制备不同生长阶段的多孔硅样品,通过表面形貌观测及微观结构表征,获得从单晶硅到多孔硅形成过程所涉及的各种晶... 详细信息

采用电化学阳极氧化法,对p型单晶硅施加30 mA/cm^2的恒定电流密度,在40%氢氟酸溶液中和氮气保护气氛下分别极化1、3和5 min,制备不同生长阶段的多孔硅样品,通过表面形貌观测及微观结构表征,获得从单晶硅到多孔硅形成过程所涉及的各种晶态组成的相对比例。结果表明:不同极化时间制得的单晶硅表面均形成了海绵状均匀分布的纳米孔洞结构。在多孔硅的形成过程中,单晶硅结构发生了显著的晶态转变和晶粒尺寸变化,导致大单晶、纳米晶和无定形态并存,晶粒直径从初期的1.41 nm减小到并保持在0.65 nm,而晶态的转变和晶粒尺寸的变化被认为与晶格畸变程度有关。

关键词：多孔硅单晶硅 Raman光谱无定形晶格畸变

光照和加热条件下Pt/TiO_2催化二氧化碳加氢(英文)

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分子催化 2014年第5期28卷 436-449页

作者：陈术清吕功煊中科院兰州化学物理研究所羰基合成与选择氧化国家重点实验室甘肃兰州730000 中国科学院大学北京100080

浸渍法制备了Pt负载量为0.5 to 2%的Pt/TiO2催化剂,考察它们在光照和加热条件下二氧化碳催化加氢性能.结果表明,二氧化碳加氢反应均可在Pt/TiO2的催化下进行,但在不同反应条件下加氢反应通过不同方式进行.在加热条件下,二氧化碳可转化... 详细信息

浸渍法制备了Pt负载量为0.5 to 2%的Pt/TiO2催化剂,考察它们在光照和加热条件下二氧化碳催化加氢性能.结果表明,二氧化碳加氢反应均可在Pt/TiO2的催化下进行,但在不同反应条件下加氢反应通过不同方式进行.在加热条件下,二氧化碳可转化为一氧化碳和甲烷,且在低温加热条件下一氧化碳是主产物(CO选择性为100%,250℃,0.5%Pt/TiO2).在1.5%Pt/TiO2催化剂上,当反应温度从250℃升高到450℃时,CH4的选择性由0增加到60.94%.同时,增加Pt的负载量也会导致CH4的选择性的增加.然而,在光照条件下,产物只有甲烷.CO2-TPD结果表明,二氧化碳通过羰基基团与作为吸附中心的Pt相连接.结合催化活性与表征结果,提出在光照条件下,反应可能以二氧化碳和氢气分别被光生电子活化反应生成甲酸中间体,随后经由甲酸加氢和脱水生成甲烷的机理进行.而在加热条件下,反应可能以二氧化碳首先吸附在催化剂表面形成羰基Pt物种,随后加氢生成一氧化碳,一氧化碳继续加氢生成甲烷的机理进行.

关键词：光催化热催化 CO2加氢

A parathyroid hormone related supramolecular peptide for multi-functionalized osteoregeneration

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Bioactive Materials 2024年第4期34卷 181-203页

作者： Zhuowen Hao Qinyu Feng Yi Wang Ying Wang Hanke Li Yingkun Hu Tianhong Chen Junwu Wang Renxin Chen xuan lv Zhiqiang Yang Jiayao Chen Xiaodong Guo Jingfeng Li Department of Orthopedics Zhongnan Hospital of Wuhan UniversityWuhan430071China Department of Obstetrics and Gynecology Renmin Hospital of Wuhan UniversityWuhan430060China Department of Orthopedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

Supramolecular peptide nanofiber hydrogels are emerging biomaterials for tissue engineering,but it is difficult to fabricate multi-functional systems by simply mixing several short-motif-modified supramolecular peptides because relatively abundant motifs generally hinder nanofiber cross-linking or the formation of long *** bioactive factors to the assembling backbone is an ideal strategy to design multi-functional supramolecular peptides in spite of challenging synthesis and ***,a multi-functional supramolecular peptide,P1R16,is developed by coupling a bioactive factor,parathyroid hormone related peptide 1(PTHrP-1),to the basic supramolecular peptide RADA16-I via solid-phase *** is found that P1R16 self-assembles into long nanofibers and co-assembles with RADA16-I to form nanofiber hydrogels,thus coupling PTHrP-1 to hydrogel matrix.P1R16 nanofiber retains osteoinductive activity in a dose-dependent manner,and P1R16/RADA16-I nanofiber hydrogels promote osteogenesis,angiogenesis and osteoclastogenesis in vitro and induce multi-functionalized osteoregeneration by intramembranous ossification and bone remodeling in vivo when loaded to collagen(Col)*** red blood marrow formation,ideal osteointegration and adapted degradation are observed in the 50%P1R16/Col scaffold ***,this study provides a promising strategy to develop multi-functional supramolecular peptides and a new method to topically administrate parathyroid hormone or parathyroid hormone related peptides for non-healing bone defects.

关键词： Supramolecular peptide nanofiber hydrogels Parathyroid hormone Self-assembly Co-assembly Bone tissue engineering

基于N-(9-蒽甲基)-L-组氨酸的NOR荧光逻辑门

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物理化学学报 2008年第10期24卷 1902-1906页

作者：宗国强吕功煊中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室兰州730000 中国科学院研究生院北京100049

合成了一个新的组氨酸衍生物,N-(9-蒽甲基)-L-组氨酸(1),并对其进行了元素分析、电喷雾电离质谱(ESI-MS)、核磁共振氢谱(1H-NMR)和碳谱(13C-NMR)等波谱表征.考查了pH值及15种不同金属离子对其荧光强度的影响.实验结果表明,中性水溶液条... 详细信息

合成了一个新的组氨酸衍生物,N-(9-蒽甲基)-L-组氨酸(1),并对其进行了元素分析、电喷雾电离质谱(ESI-MS)、核磁共振氢谱(1H-NMR)和碳谱(13C-NMR)等波谱表征.考查了pH值及15种不同金属离子对其荧光强度的影响.实验结果表明,中性水溶液条件下,Zn2+和Cd2+能使体系荧光增强,而Pb2+、Co2+、Hg2+、Ni2+和Cu2+等则使体系荧光有不同程度的猝灭.其中,Cu2+和Ni2+猝灭能力最强,它们与化合物1均形成了物质的量比为1∶2的配合物,络合常数分别为2.88×106和1.12×106L2·***2+和Ni2+对化合物1的荧光猝灭为静态猝灭过程.在此基础上,以Cu2+和Ni2+作为两个输入信号,以蒽的特征荧光发射作为输出信号,构建了一个NOR荧光分子逻辑门.

关键词：荧光逻辑门 L-组氨酸蒽 Cu2+ Ni2+

纳米Au/NaZSM-5催化剂的控制制备及催化性能

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高等学校化学学报 2009年第1期30卷 129-134页

作者：毕玉水吕功煊泰山医学院化学与化学工程学院泰安271016 中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室兰州730000

采用硝基甲烷还原-胶体负载法制备了粒径可控的系列高分散纳米Au/NaZSM-5催化剂.以多相CO催化氧化为模型反应,考察了Au微粒尺寸、pH值、反应温度、反应时间、焙烧活化温度以及Au含量等条件对催化剂性能的影响,并利用透射电子显微镜(TEM)... 详细信息

采用硝基甲烷还原-胶体负载法制备了粒径可控的系列高分散纳米Au/NaZSM-5催化剂.以多相CO催化氧化为模型反应,考察了Au微粒尺寸、pH值、反应温度、反应时间、焙烧活化温度以及Au含量等条件对催化剂性能的影响,并利用透射电子显微镜(TEM)、X射线粉末衍射(XRD)、X射线光电子能谱(XPS)和氢气程序升温还原(H2-TPR)等技术对催化剂表面化学状态和体相结构进行了表征.实验结果表明,制备条件和反应条件对Au粒子尺寸及所得催化剂活性有较大影响,催化剂性能与Au微粒粒径之间存在明显的尺寸依赖关系.

关键词：纳米Au/NaZSM-5催化剂粒径可控 CO氧化

Current advances in circulating inflammatory biomarkers in atherosclerosis and related cardio-cerebrovascular diseases

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Chronic Diseases and Translational Medicine 2017年第4期3卷 207-212页

作者： Jun-xuan lv Qi Kong Xin Ma Department of Neurology Xuanwu Hospital of Capital Medical University National Clinical Research Center for Geriatric Disorders Clinical Center for Cardio-cerebrovascular Disease Capital Medical University Beijing 100053 China

Atherosclerosis (AS) is a systemic chronic disease affecting both the coronary and cerebral arteries. Inflammation plays a key role in the initiation and progression of AS, and numerous inflammatory factors have been proposed as potential biomarkers. This article reviews recent research in studies on major circulating inflammatory biomarkers to identify surrogates that may reflect processes associated with AS development and the risk of AS-related vascular events, such as Von Willebrand factor, lectin-like oxidized low-density-lipoprotein receptor-1, soluble urokinase plasminogen activator receptor, regulated upon activation, normal T-cell expressed and secreted, and microparticles, which may provide new perspectives for clinical AS evaluation and risk stratification.

关键词： Atherosclerosis Plaques Inflammatory biomarkers Risk factors