F.J. Shan
,
C.S. Liu
,
S.H. Wang
,
G.C. Qi
金属学报(英文版)
The corrosion behavior of hot dip galvanized steel
pretreated with bis-[triethoxy-\linebreak\noindent silylpropyl]
tetrasulfide (BTESPT) modified with alumina particles was studied.
The corrosion resistance of the passiving films was evaluated by
Tafel polarization curve and electrochemical impedance spectroscopy.
The films formed on the galvanized steel substrate were
characterized by Fourier transform infrared spectroscopy and energy
dispersive X-ray spectrometry. The surface morphology of the treated
hot dip galvanized steel samples was observed by Field Emission
Scanning Electron Microscope. The results show that the
pretreatments on the basis of silane films modified with nanoalumina
particles have reduced both anodic and cathodic current densities,
and increased total impedance in the measured frequency,
consequently, improving corrosion protection for hot dip galvanized
steel during immersion in NaCl solutions compared to chromate films
and silane films.
关键词:
Bis-sulfursilane
,
null
,
null
,
null
,
null
S.H. Wang
,
C.S. Liu
,
F.J.Shan
,
G.C. Qi
金属学报(英文版)
The amino-tri-(methylenephosphonic acid) layers were adsorbed on the surface of AA6061 aluminum alloy for improving the lacquer adhesion and corrosion inhibition as a substitute for chromate coatings. The surface structure and characteristic of the amino-tri-(methylenephosphonic acid) layers on AA6061 aluminum alloy were investigated by means of XPS and ATR-FTIR analysis. The analyzed results showed that the amino-tri-(methylenephosphonic acid) adsorption layers adsorb on the surface of aluminium alloy $via$ acid-base interaction in a bi-dentate conformation. After the amino-tri-(methylenephosphonic acid) layers were coated with epoxy resin, the layers showed good adhesive strength and favorable corrosion resistance in contrast to
chromate coatings.
关键词:
Amino-tri-(methylenephosphonic acid)Layer
,
null
,
null
,
null
黄爱华
,
金鸣林
,
李和兴
,
房永征
材料导报
试验是以2种含不同QI的煤沥青为原料,采用变径反应管进行热转化反应制备有序性中间相的研究.试验采用偏光显微镜和扫描电镜(SEM)观察了原料各反应阶段的微观结构,考察了QI对热转化过程中中间相有序生长的影响,分析了热转化过程中软化点及族组分的变化.结果表明:少量的喹啉不溶物含量不会阻碍中间相有序的发展.高QI(2.03%)原料易生成镶嵌结构的中间相体,高温处理后样品呈轴状、短纤维、层片松散的石墨化焦结构;含低QI(0.11%)的原料能生成较好的、大区域的中间相体,域结构的中间相体在外力导向和内部裂解气流的作用下容易生成有序的半焦,高温处理后呈大区域、片层紧密、有序性强的细纤维焦结构.同时研究发现,在热转化过程中可通过测定软化点(SP)和TI含量来确定中间相转化程度.软化点约低于250℃、TI为75%左右时为初始中间相区域体形成阶段、半焦生成的前期.
关键词:
煤沥青
,
热转化反应
,
喹啉不溶物
,
中间相
周光明
,
梁中全
,
赵谦
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2004.05.005
研究了C/G(碳/玻)层内混杂单向复合材料的力学性能,对其拉伸、弯曲、层间剪切、振动阻尼等性能进行了实验研究,并与同样铺层的纯C、G复合材料进行了对比分析.研究表明:C/G层内混杂复合材料可充分利用C、G纤维的各自优点,改善单一材料的模量、强度、断裂韧性、振动阻尼特性等力学性能,模量预测值与实验值较为接近,强度因影响因素较多,二者存在一定的差异,力学性能随C、G体积分数的变化符合混合律,说明了实验方法的合理性.通过C、G相对体积分数的合理设计可满足结构的实际要求.
关键词:
层内混杂
,
复合材料
,
力学性能
,
实验
杭祖圣
,
谈玲华
,
黄玉安
,
应三九
,
徐复铭
功能材料
在半封闭系统中采用直接热解三聚氰胺的方法制备了C3N4,XRD、XPS及元素分析的结果证明了产物是类石墨相C3N4(g-C3N4).用热分析(TG/DTG)研究了g-C3N4的热分解过程.通过迭代法计算了热分解反应活化能Ea,采用积分法结合36种动力学函数来判断g-C3N4热分解的机理函数.计算结果表明,g-C3N4的平均热分解活化能Ea为178.59kJ/mol,可能的动力学函数积分形式是g(a)=[-In(1-a)]4,指前因子A为21.67s-1,对应的热分解动力学方程为:dα/dT=(21.67/β)exp(-178.59×103/RT)×1/4(1-α)[-ln(1-α]-3
关键词:
非等温热重法
,
g-G3N4
,
热分解动力学
,
迭代法
Xifeng Lu Qilong Wang Deliang Cui
材料科学技术（英文）
g-C3N4/TiO2 composite were prepared by hydrolysis of Ti(OC4Hn 9 )4 and the precursors of g-C3N4 at room temperature and annealing in nitrogen atmosphere. X-ray diffraction results revealed that all the products were anatase structure. The chemical nature of O, N of the g-C3N4/TiO2 were identified by X-ray photoelectron spectroscopy, presenting N-Ti-O and N-Ti-N doping status of the composite. The g-C3N4/TiO2 composite showed better photocatalytic activity for the UV and visible-light degradation of Rhodamine B.
关键词:
Composite materials
,
Chemical synthesis
,
X-ray photoelectron spectroscopy (XPS)
楚增勇
,
原博
,
颜廷楠
无机材料学报
doi:10.15541/jim20130633
利用光催化剂将太阳能转化为人类可以直接利用的能量，并用其解决地球资源的枯竭和生存环境的恶化是可再生清洁能源研究的一个方向。g-C3N4的独特结构赋予其良好的光催化性能，使之成为光催化领域的研究热点。目前在光催化领域， g-C3N4主要用于催化污染物分解、水解制氢制氧、有机合成及氧气还原。在实际应用中，为进一步提高 g-C3N4的光催化效果，科研工作者开发了多种改进方法，例如物理复合改性、化学掺杂改性、微观结构调整等。本文主要论述了 g-C3N4在光催化领域的应用以及光催化性能的改进方法，简要阐述了光催化和各种改进方法的机理，分析了目前g-C3N4在光催化领域面临的问题和挑战，展望了g-C3N4的应用前景。
关键词:
g-C3N4
,
光催化
,
改进方法
,
综述
郑小刚
,
杜京城
,
李子黎
,
付孝锦
,
由耀辉
,
刘勇
人工晶体学报
采用浸渍法制备不同掺杂量的负载型光催化剂Ni/g-C3N4,并考察其在可见光照下对亚甲基蓝的光降解性能.利用XRD、FT-IR、SEM、TEM、XPS、N2-sorption和ICP-OES等手段表征Ni/g-C3N4样品.研究表明,Ni/g-C3N4催化剂的光催化活性随着金属镍粒子掺杂量的增加而增大,随着亚甲基蓝浓度的增大而减小,其中金属镍掺杂量4.0wt%的样品4-Ni/g-C3N4表现出优异的光催化活性和光降解稳定性.这是由于4-Ni/g-C3N4样品的光降解过程中产生了超氧自由基、羟基自由基和空穴等活性物质,其中超氧自由基起主导作用.金属Ni0离子在光生电子作用下生成Ni2+,O2分子得到电子生成O2·-自由基.这些活性物质的产生有助于光生电子-空穴对的分离和抑制其复合速率,从而实现可见光下高效催化降解亚甲基蓝.
关键词:
Ni/g-C3N4
,
掺杂效应
,
亚甲基蓝
,
光降解性能
