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TEMPERING RESPONSE OF A DEFORMED LOW CARBON DUAL PHASE STRUCTURE

JIN Man , JIANG Zhonghao , NAN Shenghui , HU Jiandong , LIAN jianshe(Jilin University of Technology , Changchun , China)(Manuscript received 8 February 1995)Correspondent:LI Geping , (Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China)

金属学报(英文版)

The low carbon dual phase structure was cold de formed first,then was tempered at 200 to 600℃.The variation in strength and ductility during tempering of the steel was investigated.It was found that a fter the de formed dual phase structure was tempered at 200 to 600℃, with the increase in the tempering temperature the tensile strength decreases rapidly;the lotal elongation remains constant at 200 to 500℃ but began to rise dramatically at a critical temperature between 500 and 600℃.However,when the non-deformed dual phase structure was tempered at the same temperature range,the tensile strength decreases and the total elongation increases continuously with the increase of temperature.It was demonstrated from TEM analysis that precipitating carbides density along the boundaries ofmartensite lath and the recrystallized grains are responsible for the tempering response ofthe de formed dual phase structure.

关键词: :de formed dual phase structure , null , null

采用NaN3燃烧合成高α相氮化硅粉体

王飞 , 沈卫平 , 葛昌纯

稀有金属材料与工程

采用燃烧合成方法,以NaN3作为固态氮化剂,制备了α相含量高达97%以上的氮化硅粉体.研究了外部氮气压力对于燃烧合成氮化硅粉体的影响.NaN3的加入主要是为燃烧合成反应提供了比N2分子更高化学活性的内部氮源(N3原子团和N原子),同时作为Si-N反应的催化剂,使Si粉在氮气中的燃烧合成反应更加容易进行.适量的NaN3加入能够促进Si粉的完全氮化并提高燃烧产物中的α-Si3N4含量.详细探讨了采用NaN3作为固态氮化剂条件下可能的氮化硅燃烧合成机理.

关键词: 燃烧合成 , NaN3 , 氮化硅

天然海水中NaN3对316L不锈钢表面微生物膜催化阴极氧还原的影响

聂鸳鸳 , 段继周 , 杜敏 , 侯保荣

中国腐蚀与防护学报 doi:10.11902/1005.4537.2013.160

利用荧光显微观察技术选择临界使用浓度的NaN3,分别在O2及N2气氛下采用循环伏安及电化学阻抗技术研究其氧还原过程的电化学行为.结果表明,不锈钢表面的生物膜能够加大还原峰电流密度值,当使用临界浓度的NaN3处理不锈钢试样后,还原峰值明显减小,且峰电位均负移.微生物膜能够促进电子传递给最终电子受体O2,同时降低不锈钢材料发生腐蚀的可能性.由此推测,天然海水中,316L不锈钢表面微生物膜改变了传统阴极氧还原的电子传递途径,即加速了O2作为最终电子受体的电子传递过程,催化了O2的还原;同时,还能够抑制不锈钢材料的腐蚀.

关键词: 天然海水 , 316L不锈钢 , NaN3 , 微生物膜 , 细胞色素c氧化酶 , 氧还原

纳米Al2O3对尼龙6结晶性能的影响

张玉庆 , 钟明强 , 蔡伟乐 , 蒋东升

高分子材料科学与工程

采用硅烷偶联剂KH-560对纳米氧化铝( nano-Al2O3)进行表面处理后与尼龙6(PA6)熔融共混制备PA6/nan-Al2O3复合材料,用扫描电镜(SEM)观察了材料断面形貌,借助差示扫描量热仪(DSC)研究了原料配比及降温速率对PA6/nan-Al2O3复合材料结晶性能影响.结果表明,nan-Al2O3在PA6结晶过程中起异相成核作用,限制了PA6分子链运动,使复合材料玻璃化转变温度及结晶度提高,非等温结晶过冷度降低,结晶速率加快;材料结晶温度、结晶焓、结晶度随降温速率增加而下降.

关键词: 尼龙6 , 纳米氧化铝 , 复合材料 , 结晶性能 , 成核作用

EFFECTIVE-MEDIUM THEORY OF PIEZOELECTRIC COMPOSITES

Journal of Applied Physics

Based on the developed multiple-scattering theory [C.-W. Nan and F. S. Jin, Phys. Rev. B 48, 8578 (1993)], an effective-medium theory (EMT) is proposed to treat coupled electromechanical behavior in composite media. The explicit relations for determining effective behavior of piezoelectric composites are derived. To illustrate the technique, numerical results of piezoelectric ceramic/epoxy composites for various particle shapes are presented over the whole range of concentrations. The EMT estimates are shown to be in good agreement with available experimental results. Porous piezoelectric ceramics are also discussed. The EMT predicts a similar critical behavior for heterogeneous piezoelectric materials to recent experiments.

关键词: electromechanical properties;ceramics

利用苯热合成方法制备氮化硼纳米环

陈志 , 赖泽锋 , 孙传涛 , 伦宁 , 陆希峰 , 王琪珑 , 崔得良

功能材料

利用苯热合成方法,以BCl3和NaN3为原料制备了氮化硼纳米晶,研究了影响氮化硼微观形貌的关键因素(例如,反应温度、原料的混合速度等).在此基础上,通过调整两种原料的混合反应速度制备了BN纳米环,并利用涡旋诱导作用对BN纳米环的生成机理进行了初步讨论.

关键词: 氮化硼 , 纳米环 , 苯热合成 , 微观形貌 , 涡旋诱导

立方氮化铝纳米晶的溶剂热合成及其对二甲苯催化性质的研究

李玲 , 郝霄鹏 , 于乃森 , 徐现刚 , 崔德良 , 蒋民华

人工晶体学报 doi:10.3969/j.issn.1000-985X.2004.03.004

低温(280℃)条件下,通过二甲苯中AlCl3和NaN3的反应制备出了AlN纳米微粒.700℃退火48h后,得到了纯的立方相AlN纳米晶.通过XRD、FTIR和定域电子衍射分析,验证了立方相AlN纳米晶的生成.经XRD和TEM分析,纳米晶的平均粒度约为3nm.色质联(GC-MS)检测结果显示,由于AlN纳米颗粒对二甲苯的催化作用,使二甲苯发生聚合和杂化环反应,得到了二联苯、萘、蒽、三甲基咔唑及咔唑胺等多环芳烃.作为对比实验,分别研究了NaN3和AlCl3对二甲苯的催化性能,发现没有多环芳烃的生成.

关键词: AlN纳米晶 , 溶剂热合成 , 二甲苯 , 催化

改性对高钛渣物相组成的影响研究

徐福昌 , 廖亚龙 , 雷鹰 , 段昕辉 , 李长龙 , 王欣 , 刘建华

钛工业进展 doi:10.3969/j.issn.1009-9964.2011.01.006

以CaO,NaN03为添加剂.研究了添加剂配比和焙烧温度对高钛渣物相组成的影响.焙烧实验结果说明,改性焙烧使高钛渣中的TiO2转变为钛酸钙,且焙烧温度越高,CaO添加剂配比越大,相转变越完全.高钛渣改性的适宜条件:高钛渣与CaO,NaNO3的配比为10:8:3;焙烧温度为1200~1 300℃;焙烧时间为120 min.对改性后的高钛渣进行了初步的酸解浸出实验,在焙烧温度1 200℃、焙烧时间120 min、高钛渣与CaO,NaNO3的配比为10:8:3时,浸出率可达到96.23%.

关键词: 高钛渣 , 添加剂 , 焙烧温度 , 改性 , 浸出率

洋葱状炭纳米粒子的无催化剂合成

M.Bystrzejewski , M.H.Rummeli , T.Gemming , H.Lange , A.Huczko

新型炭材料 doi:10.1016/S1872-5805(09)60011-1

描述了基于NaN_3-C_6Cl_6混合物热解一步合成洋葱状碳纳米粒子的方法.应用EMS, XRD, Ramans研究了缓冲气体(Ar或空气)对炭产物的得率、形貌和结构的影响.产物包含洋葱炭、非晶碳和NaCl,通过简单的纯化处理即可完全除去副产物.洋葱状炭纳米粒子的形成由热解过程中压力迅速增加产生的震动波诱导苯基活性分子合并所制.

关键词: 碳纳米洋葱 , 热解 , 气相反应 , XRD , Raman光谱

Catalytic Graphitization of Phenolic Resin

Mu Zhao

材料科学技术(英文)

The catalytic graphitization of thermal plastic phenolic-formaldehyde resin with the aid of ferric nitrate (FN) was studied in detail. The morphologies and structural features of the products including onion-like carbon nanoparticles and bamboo-shaped carbon nanotubes were investigated by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction and Raman spectroscopy measurements. It was found that with the changes of loading content of FN and residence time at 1000°C, the products exhibited various morphologies. The TEM images showed that bamboo-shaped carbon nan-otube consisted of tens of bamboo sticks and onion-like carbon nanoparticle was made up of quasi-spherically
concentrically closed carbon nanocages.

关键词: Nanostructures

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