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Synthesis of higher molecular weight PAN and its copolymers for carbon fibers

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Journal of University of Science and Technology Beijing 2005年第4期12卷 376-382页

作者： wangxi zhang Yanzhi Wang Jieying Liang Jie Liu Department of Materials and Chemical Engineering Zhongyuan University of Technology Zhengzhou 450007 China Department of Carbon Fibers and Composites Beijing University of Chemical Technology Beijing 100029 China

Higher molecular weight polyacrylonitrile （PAN） was obtained by the free-radical suspension copolymerization of itaconic acid （IA） and acrylonitrile （AN） which was carded out in DMSO/H2O using 2,2＇-azodiisobutyronitrile （AIBN） as the initiator. The effects of polymerization parameters, such as IA monomer concentration and DMSO/H2O ratio, on the conversion of polymerization and number-average molecular weight are specially described. The copolymerization reaction rate and the number-average molecular weight of the resultant copolymers decrease with the result of high chain transfer constant of DMSO. For the copolymerization of AN and IA, with the inclusion of the good solvent DMSO, the solution degree of AN in DMSO/H2O is higher than that in water, as a result, the resulting copolymer pellets range from soft bulk to solid grain, as characterized by the use of SEM. Higher molecular weight P（AN-co-IA） copolymers have a lower initiation of exothermal reaction temperature and wider DSC exothermal peaks compared with PAN homopolymers, which corresponds with the results of an IR study.

关键词： polyacrylonitrile acrylonitrile polymerization polymer

A Summary of the Forum on Language Learning Theory——Editing Board of Chinese Teaching in the World Editing Board of Applied Linguistics Editing Board of Language Teaching and Linguistic Studies

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世界汉语教学 1992年第4期6卷 246-260页

作者： zhang wangxi, Liu Runqing

1. Participants Initiated by Lü Bisong from Beijing Language Institute and sponsored by the Editing Boardsof Chinese Teaching in the World, Applied Linguistics, and Language Teaching and LinguisticStudies, a forum on language learning theory was held from May 14 to 18, 1992 in Beijing, in or-der to push forward China’s research in language teaching theories and language teaching method-ology. The suggested areas for discussion at the Forum included: 1. the scope of research in lan-guage learning theory; 2. significance of these theories for language teaching; 3. relation and dif-ference between "learning" and "acquisition" ; 4. similarities and differences between L1 and L2learning; 5. relation between spoken language and written language; 6. research methods in lan-guage learning theory; 7. the state of the art of this research in other countries; 8. the state ofthe art in China; 9. direction and focus in China’s research in the field;10. the future of this re-

关键词：汉语教学世界内功习得责任编辑学得学习获得掌握

Hybrid Ti_2AlC Bonded Diamond Composites Prepared by a Self-propagation Sintering Approach

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Journal of Wuhan University of Technology(Materials Science) 2019年第1期34卷 82-85页

作者： zhang wangxi LIANG Baoyan LUO Wei WANG Yanzhi School of Materials and Chemical Engineering Zhongyuan University of Technology Department of Chemical Engineering Sichuan Vocational College of Chemical Technology

Ti, Al, graphite and diamond powders were used as raw materials to prepare Ti_2AlC matrixbonded diamond composite using self-propagating high-temperature synthesis(SHS) method. The effect of diamond size and content on the fabrication of Ti_2AlC-bonded diamond material was investigated. Results showed that Ti_2AlC matrix-bonded diamond composites could be obtained by SHS. The phase composition and microstructure of the Ti_2AlC-bonded diamond material were influenced by the diamond content and size. When the diamond(93 μm) additive amounts were 10% and 20%, the product phases included Ti_2AlC, TiC and Al_3Ti. However, excess Ti and Al persisted in the sample that contained 30% diamond. Diamond bonded well with the matrix in the sample that contained 10% diamond. Moreover, addition of coarse diamond particles with sizes of 93 and 125 μm produced a mainly Ti_2AlC matrix. However, diamond adequately reacted with Ti to form TiC when finer diamond particles(5 and 10 μm) were used.

关键词： titanium aluminum carbide diamond content size self-propagation high temperature sintering

In-situ Synthesis of Cr_(3)C_(2) Nanosheets by Carbon Reduction Route from Cr_(2)AlC

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Journal of Wuhan University of Technology(Materials Science) 2022年第3期37卷 364-369页

作者： LIANG Baoyan DAI Zhen zhang wangxi JIAO Mingli FENG Xiaochen zhang Yanli LIU Ying zhang Ruijie YANG Li Materials and Chemical Engineering School Zhongyuan University of TechnologyZhengzhou 450007China National and Local Joint Laboratory of Engineering of Diamond Technology Zhengzhou 451191China Faculty of Metallurgical and Energy Engineering Kunming University of Science and technologyKunming 650093China

Carbon black and Cr_(2)AlC were used as raw materials to obtain a large number of Cr_(3)C_(2)nanosheets by means of the molten salt heat treatment at 1100℃for 1.5 *** showed that carbon black can promote the decomposition of a large number of Cr_(2)AlC to form Cr_(3)C_(2)and Cr_(7)C_(3)nanoparticles at 1100℃in the absence of molten *** a molten salt environment,carbon black can promote the complete decomposition of Cr_(2)AlC to form Cr_(3)C_(2)and Cr_(7)C_(3)*** thickness of chromium carbide nanosheets is approximately 10-20 nm,and the length is approximately 100-200 *** addition of excess carbon black can promote the complete decomposition of Cr_(2)AlC into a material with Cr_(3)C_(2)as the main phase.

关键词： nanosheets Cr_(3)C_(2) carbon black molten salt synthesis

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化学气相沉积法合成金刚石的研究进展

陶瓷学报 2021年第4期42卷 537-546页

作者：张旺玺中原工学院材料与化工学院河南郑州451191 河南省金刚石碳素复合材料工程技术研究中心河南郑州451191 河南省金刚石工具技术国际联合实验室河南郑州451191

为了更深入地了解化学气相沉积法合成金刚石,对化学气相沉积法合成金刚石的主要类型、合成的金刚石结构及主要形态和主要应用领域进行了综述。化学气相沉积法合成金刚石的方法可分为微波等离子体化学气相沉积法、热丝化学气相沉积法和... 详细信息

为了更深入地了解化学气相沉积法合成金刚石,对化学气相沉积法合成金刚石的主要类型、合成的金刚石结构及主要形态和主要应用领域进行了综述。化学气相沉积法合成金刚石的方法可分为微波等离子体化学气相沉积法、热丝化学气相沉积法和直流电弧等离子体喷射化学气相沉积法。化学气相沉积法合成的金刚石的形态主要有金刚石单晶、微纳米级多晶金刚石膜和类金刚石膜。该法合成的金刚石主要用作钻石培育、刀具涂层、半导体器件材料、水处理电极材料以及其他功能材料。由于该合成金刚石在质量、尺寸、净度、功能等方面的众多优势,预计在未来几十年内,在产量上快速赶上高压高温法,在质量上超过高压高温法。为了加快化学气相沉积法合成金刚石的发展,应该从提高速率、提升质量、加大尺寸、细化功能四个方面深入开展化学气相沉积法合成金刚石的技术研发。

关键词：化学气相沉积金刚石超硬材料微波等离子体

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钢筋半套筒灌浆连接的高温静力拉伸性能

华南理工大学学报（自然科学版） 2019年第1期47卷 48-55页

作者：张望喜邓曦何超湖南大学工程结构损伤诊断湖南省重点实验室湖南长沙410012 湖南大学土木工程学院湖南长沙410012

对12个钢筋半套筒灌浆连接试件在高温下进行了静力拉伸试验,并将12根同批次钢筋在同条件下进行试验作为参照.研究了温度对钢筋半套筒灌浆连接的影响,以及钢筋半套筒灌浆连接与钢筋在高温下力学性能的差异.结果表明:半套筒灌浆连接试件... 详细信息

对12个钢筋半套筒灌浆连接试件在高温下进行了静力拉伸试验,并将12根同批次钢筋在同条件下进行试验作为参照.研究了温度对钢筋半套筒灌浆连接的影响,以及钢筋半套筒灌浆连接与钢筋在高温下力学性能的差异.结果表明:半套筒灌浆连接试件在高温下的极限抗拉强度与钢筋相近,试件破坏形式为钢筋被拉断、钢筋刮犁式拔出两种;钢筋半套筒灌浆连接在200℃及以下温度条件下与钢筋单向拉伸的本构关系相似,在400℃及以上温度条件下其力学性能与钢筋存在一定差异;在常温及400℃高温下,试件的破坏模式均为钢筋被拉断,在600℃高温下半套筒灌浆连接灌浆段钢筋可能先被拨出,而非拉断.

关键词：半套筒灌浆连接钢筋静力拉伸力学性能破坏形态

Synthesis of hierarchical Ni3S2 by ion exchange method for supercapacitors application

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Synthesis of hierarchical Ni3S2 by ion exchange method for s...

河南省化学会2016年学术年会

作者： Shaobo Huang wangxi zhang Liwei Mi Weihua Chen Center for Advanced Materials Research Zhongyuan University of Technology College of chemistry and Molecular Engineering Zhengzhou University

Metal sulfide with self-assembly of three dimensional(3D) hierarchical nanostructures has attracted much attention, owing to their multiple morphological features. Herein, we fabricated a series of NiS electrode materials with nickel foam as a partly self-sacrificial template by a facile one-pot hydrothermal route. The as-synthesized hierarchical Ni@NiS nanorods materials were consisted of nanosheets with the thickness of about 20 nm. To improve the electrochemical performance of Ni@NiS, different anion and cation ion were successfully introduced into the hierarchical Ni@NiSmaterial. The material structure was virtually retained and single-crystal-to-single-crystal transformation was achieved in the process. Moreover, the electrochemical properties of these three materials were studied by cyclic voltammetry measurements and galvanostatic charge–discharge tests. The results indicated that the rate performance was improved significantly by ion exchange.

关键词： Hierarchical Ni3S2 Ion exchange Supercapacitors device

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考虑施工误差影响的RC框架结构可靠性分析

湖南大学学报（自然科学版） 2017年第7期44卷 69-77页

作者：张望喜刘有程超男湖南大学土木工程学院湖南长沙410082

为分析施工误差对RC框架结构可靠性的影响,对某钢筋混凝土框架结构工程进行现场测量,获得了梁柱截面尺寸、保护层厚度、箍筋间距和混凝土抗压强度等施工误差的统计分布规律.基于工程结构可靠度的基本理论和承载能力极限状态方程,采用验... 详细信息

为分析施工误差对RC框架结构可靠性的影响,对某钢筋混凝土框架结构工程进行现场测量,获得了梁柱截面尺寸、保护层厚度、箍筋间距和混凝土抗压强度等施工误差的统计分布规律.基于工程结构可靠度的基本理论和承载能力极限状态方程,采用验算点法计算了实际工程中典型的框架梁和框架柱的可靠指标,并详细分析了各施工误差对构件可靠指标和结构可靠性分级的影响,以及影响钢筋混凝土结构框架结构可靠度的参数敏感性.分析结果表明,施工误差对结构构件的可靠性存在不可忽视的影响.本文研究结果有助于工程设计、施工和监管过程中把握施工误差中需严格控制的重点参数和偏差范围.

关键词： RC框架结构施工误差承载能力极限状态结构可靠度参数敏感性

汉语“人称代词+NP”复指结构的话语功能——基于电视剧《亮剑》台词的分析

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当代修辞学 2010年第5期 50-62页

作者：张旺熹北京语言大学汉语水平考试中心北京100083

本文在对电视剧《亮剑》台词作定量考察的基础上,对汉语中"我李云龙"一类的"人称代词+NP"复指结构进行分析。本文从结构的内部构成、NP的语义特征和句子谓语及情态特征等多侧面进行描写。本文认为:汉语"人称代词+NP"复指结构是一种隐性... 详细信息

本文在对电视剧《亮剑》台词作定量考察的基础上,对汉语中"我李云龙"一类的"人称代词+NP"复指结构进行分析。本文从结构的内部构成、NP的语义特征和句子谓语及情态特征等多侧面进行描写。本文认为:汉语"人称代词+NP"复指结构是一种隐性述谓结构,其"NP"的功能在于凸显"人称代词"所指代对象在当下话语情境中说话人所认定的某种属性特征,从而造成该种结构表达的强主观性。这种强主观性的凸显,在相当程度上制约着句子[-事件]的特征。因此我们认为,汉语"人称代词+NP"结构是一种话语功能独特的短语结构,其主要的话语功能在于凸显代词所指对象在特定话语情境中所拥有的某种特定属性要素,从而规定着言者对这一对象的主观评价或是预测代词所指对象在话语情境中所要采取的特定行为。

关键词：人称代词复指结构主观性隐性述谓关系话语功能