熊凯
,
朱勇平
,
王炼石
,
蔡彤旻
,
张安强
,
曾祥斌
高分子材料科学与工程
用悬浮接枝共聚法合成了乙烯-1-丁烯共聚物(PEB)与甲基丙烯酸甲酯(MMA)-丙烯腈(AN)的接枝共聚物(PEB-g-MAN).用不同性质的溶剂以抽提法将接枝共聚产物所含组分逐步分离,用傅立叶变换红外光谱(FT-IR)分析了各组分聚合物的归属.研究了AN/(MMA+AN)投料质量比(fAN)对接枝共聚反应行为及产物各组分含量的影响.用凝胶渗透色谱法(GPC)对各组分相对分子质量及其分布进行了表征.结果发现,接枝共聚体系存在PEB与MMA-AN接枝共
聚、PEB与MMA接枝均聚、MMA与AN共聚和MMA均聚等基元反应.
关键词:
乙烯-1-丁烯共聚物与甲基丙烯酸甲酯-丙烯腈接枝共聚反应
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橡胶接枝率
,
组分分离
,
傅立叶变换红外光谱
,
基元反应
,
凝胶渗透色谱法
王丽晖
,
高晓军
,
张虹
,
武吉生
兵器材料科学与工程
doi:10.3969/j.issn.1004-244X.2009.02.032
采用日立公司Z-2000原子吸收光谱仪对生铁中痕量砷和铅进行测定并讨论相关的实验条件,石墨管性能比较、酸的选择、试剂空白的控制、干扰因素及消除、基体改进剂的选择、加热参数的选择、共存离子的影响等.用10 g/LNi(NO3)2作基体改进剂,提高砷的灰化温度,检测信号得到扩大,回收率为102%和105%.方法的相对标准偏差为4.73%和4.09%,As的线性范围为0～80μg/L,Pb的线性范围为0～100μg/L.
关键词:
石墨炉原子吸收法
,
基体改进剂
,
痕量
,
灰化
,
原子化
徐军
,
张秀龙
材料研究学报
<正> 合成指定序列结构的材料是高分子设计的重要内容。交替共聚的方法是一个简单的极限例子。理论和实践上的兴趣是交替共聚的机理以及据此应用单体分子结构的或经验的参数预言交替共聚的可能性。对于后者,根据机理的不同,交替共聚的判据分为两种,即CTC 平衡常数K 的判据和基于Q-e 概念的竞聚率(r_1·r_2)判据。目前判断交替共聚的可能性仍用这宏观可测量而不是所期望的微观结构参数。但这宏观量与分子结构的联系,对于动力学判据途径,已由Alfrey,Price 的工作完成~([1]),而热力学途径,K 与
关键词:
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:
Z.A. Luo
,
H.L. Su
,
D.H. Zhang
,
G.D. Wang a
金属学报(英文版)
A new multifunction thermo-mechanical simulator was successfully developed. The accuracy of measurement and control is very high through all digital control. More than twenty tests may be fulled including tension, compression, torsion, combination large deformation that meets the study of supersteel, etc. Its performance is introduced in the paper, such as designed ideas, machine structure, man-machine interface, con- trol system, etc.
关键词:
thermo-mechanical simulator
,
null
,
null
ZHOU Ban JIN Shiming SHAO Jun CHEN Nianyi Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
China
金属学报(英文版)
An expert system,IMEC,for the retrieval and prediction of binary intermetallic compounds has been built.The rules found by chenlieal bond parameter-pattern recognition method have been used for computerized prediction.Data base of known mtermetallic compounds and chemical bond parameters of metallic elements and the knowledge proeessing system are in cluded in the expert system.By man-machine interfacing,the formation,stoichiometry and crystal type o fall binary intermetallic compounds can be predicted or retrieved.
关键词:
binary system
,
null
,
null
Physical Review B
We reconsider and interpret the mechanical properties of the recently proposed allotrope of carbon, T-carbon [Sheng et al., Phys. Rev. Lett. 106, 155703 (2011)], using density functional theory in combination with different empirical hardness models. In contrast with the early estimation based on Gao et al.'s model, which attributes to T-carbon a high Vickers hardness of 61 GPa comparable to that of superhard cubic boron nitride (c-BN), we find that T-carbon is not a superhard material, since its Vickers hardness does not exceed 10 GPa. Besides providing clear evidence for the absence of superhardness in T-carbon, we discuss the physical reasons behind the failure of Gao et al.'s and Simunek and Vackar's (SV) models in predicting the hardness of T-carbon, residing in their improper treatment of the highly anisotropic distribution of quasi-sp(3)-like C-C hybrids. A possible remedy for the Gao et al. and SV models based on the concept of the superatom is suggested, which indeed yields a Vickers hardness of about 8 GPa.
关键词:
superhard rhenium diboride;elastic-constants;ambient-pressure;metal;borides;crystals;diamond;search;boron
