Wangxi ZHANG
,
Jie LIU
,
Jieying LIANG
,
null
,
null
,
null
材料科学技术（英文）
Structural changes in carbon fibers at each stage of, especially, preoxidation process are well known to play a great role in achieving the ultimate product quality. Differential scanning calorimetry (DSC), scanning electron microscope (SEM), density method and optical microscope were used to characterize the preoxidation extent. A conventional approach, e:g., density aim, to evaluate the extent of preoxidation is not very exact. A DSC curve of a PAN precursor only can provide general information, major in the temperature regime of preoxidation reaction. However, the evaluation of a preoxidation extent, especially from conventional preoxidation temperature with a great span regime of 200~400℃, is put forward in this paper, in which the evolution of core/shell morphological structure is a kind of straightforward evidence.
关键词:
Preoxidation
,
null
,
null
Yunxia GUO
,
Jie LIU
,
Jieying LIANG
,
null
材料科学技术（英文）
Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that on the modified surface of carbon fibers, the carbon contents decreased by 9.7% and the oxygen and nitrogen contents increased by 53.8% and 7.5 times, respectively. The surface roughness and the hydroxyl and carbonyl contents also increased. The surface orientation index was reduced by 1.5% which decreased tensile strength of carbon fibers by 8.1%, and the microcrystalline dimension also decreased which increased the active sites of carbon fiber surface by 78%. The physical and chemical properties of carbon fibers surface were modified through the electrochemical oxidative method, which improved the cohesiveness between the fibers and resin matrix and increased the interlaminar shear strength (ILSS) of carbon fibers reinforced epoxy composite (CFRP) over 20%.
关键词:
Polyacrylonitrile (PAN)
,
null
,
null
,
null
Physics of Life Reviews
Commentaries by Philip W.T. Pong, Nongyue He, S.D. Liang, Tao Song, Yuri Gaididei and Sergey Volkov and Alexander Y. Grosberg on my review article (Pang, 2011 [1]) are answered. The validity of Davydov's mechanism of bio-energy transport, the completeness of theory, outstanding problems, the normalization and validity of wave function of the system in Pang' model as well as other related problems are elucidated in detail. (C) 2011 Elsevier B.V. All rights reserved.
关键词:
biological temperature;3 channels;soliton;model
Scripta Materialia
A recent comment on a previously published paper addressed the invalid explanation of the off diagonal interdiflusion coefficients of the beta-Ni(Al,Cr) phase in the Ni-Cr-Al system according to the symmetric property of the thermodynamic matrix. In this paper, the experimental data presented by Hou et al. was reanalyzed and the interdiffusion coefficient matrix was estimated again. The results of the analysis have been discussed in terms of a brief reply to the comments of Liu and Liang. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词:
Diffusion;Intermetallic compound;Ni-Cr-Al
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
李璟
,
金明
,
田东艳
,
兑关锁
复合材料学报
doi:10.3321/j.issn:1000-3851.2006.04.026
对NiTi形状记忆合金纤维拔出的力学模型进行了探讨.在恒温状态下,考虑纤维和基体间的界面摩擦力,分别用两种本构理论,即Tanaka的指数模型和C.Liang的余弦模型,讨论了形状记忆合金纤维在变轴力作用下的拉伸问题.推导了形状记忆合金纤维拔出量的表达式,并给出数值计算结果.由指数模型和余弦模型得到的结果非常吻合,证明了这种理论方法是正确的.
关键词:
形状记忆合金
,
NiTi纤维
,
拔出
,
本构模型
,
变轴力
吴成宝
,
盖国胜
,
杨玉芬
,
董怀
材料导报
阐述了预测聚丙烯(PP)/无机粒子复合材料弹性模量的复合法则、 Eistein方程及其修正、Kerner方程、Liang方程.从结构因素方面分析了弹性模量的影响因素.分析表明:无机粒子的粒径越小、分布越合理,其填充PP复合材料的弹性模量越大;与球形、方形等其它粒子相比,长径比较大的薄片状无机粒子具有更强的增强复合材料弹性模量的能力;复合材料的弹性模量随无机粒子含量的增加而提高;提高无机粒子-PP树脂的界面黏结强度以及改善无机粒子在树脂中的分散状态可以提高复合材料的弹性模量.最后指出,影响因素的定量表征和多因素分析是今后的主要研究方向.
关键词:
无机粒子
,
聚丙烯
,
复合材料
,
弹性模量
刘建国
,
安振涛
,
张倩
,
杜仕国
,
姚凯
,
王金
材料导报
doi:10.11896/j.issn.1005-023X.2017.04.030
为评估氧化剂硝酸羟胺的热稳定性,使用标准液体铝皿于3 K/min、4 K/min、5 K/min加热速率下进行热分析.借助非等温DSC曲线的参数值,应用Kissinger法和Ozawa法求得热分解反应的表观活化能和指前因子,根据Zhang-Hu-Xie-Li公式、Hu-Yang-Liang-Xie公式、Hu-Zhao-Gao公式以及Zhao-Hu-Gao公式,计算硝酸羟胺的自加速分解温度和热爆炸临界温度,并对热分解机理函数进行了研究.设计了7条热分解反应路径,采用密度泛函理论B3LYP/6-311++G(d,p)方法对硝酸羟胺的热分解进行了动力学和热力学计算.计算结果表明,硝酸羟胺热分解的自加速分解温度TsADT=370.05 K,热爆炸临界温度Te0=388.68K,Tbp0=397.54 K,热分解最可几机理函数的微分形式为f(a) =17×(1-α)18/17.硝酸羟胺热分解各路径中,动力学优先支持路径Path 6、Path 5、Path 4和Path 1生成NO和NO2,其次是Path 2、Path 7和Path 3生成N2和N2O.温度在373 K以下时,Path 1'反应无法自发进行,硝酸羟胺无法进行自发的热分解.从热力学的角度来看,硝酸羟胺在370.05K以下储存是安全的.
关键词:
硝酸羟胺
,
热分析
,
热稳定性
,
热分解机理
,
密度泛函理论
