材料期刊网

LiMn₂O₄/CNTs and LiNi_0.5Mn_1.5O₄/CNTs Nanocomposites as High-Performance Cathode Materials for Lithium-Ion Batteries

Thang Van Le , Ha Tran Nguyen , Anh Tuan Luu , Man Van Tran , Phung Loan My Le

金属学报(英文版) doi:10.1007/s40195-014-0181-9

关键词: Nanocomposites , Carbon nanotubes (CNTs) , Spinel materials , Lithium-ion batteries (LIBs)

PEB-g-MAN的合成与表征

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 , 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

Simple approach to estimating the van der Waals interaction between carbon nanotubes

Physical Review B

The van der Waals (vdW) interactions between carbon nanotubes (CNTs) were studied based on the continuum Lennard-Jones model. It was found that all the vdW potentials between two arbitrary CNTs fall on the same curve when plotted in terms of certain reduced parameters, the well depth, and the equilibrium vdW gap. Based on this observation, an approximate approach is developed to obtain the vdW potential between two CNTs without time-consuming computations. The vdW potential estimated by this approach is close to that obtained from complex integrations. Therefore, the developed approach can greatly simplify the calculation of vdW interactions between CNTs.

关键词: molecules;clusters;bundles;growth;phase;c-60

Van der Waals interactions between two parallel infinitely long single-walled nanotubes

Chemical Physics Letters

The potential energies of van der Waals (VDW) interactions between two parallel, infinitely long and perfect SWNTs with identical, and different sizes were studied based on the continuum Lennard-Jones model. The conclusion of Girifalco's work on (n, n) SWNTs that the potentials of SWNT-SWNT fell on a single curve, is also applicable to SWNTs with different sizes. We further obtained the corresponding constants of the well depth \phi(0)\ and equilibrium VDW gap g(0) for SWNTs with a radius from 2 to 25 Angstrom. (C) 2005 Elsevier B.V. All rights reserved.

关键词: carbon nanotubes;graphite;bundles;c-60;moduli;ropes

Purification of multiwalled carbon nanotubes by annealing and extraction based on the difference in van der Waals potential

Journal of Physical Chemistry B

The potential energies of van der Waals interactions between two multiwalled carbon nanotubes (MWNTs) as well as two carbon nanoparticles (CNPs) were calculated and compared on the basis of the continuum Lennard-Jones model. The well depth of the potential is 1 order of magnitude higher for MWNTs than for CNPs, indicating that MWNTs and CNPs can be separated from each other through polymer-induced steric stabilization. On the basis of this prediction, a novel method for the purification of MWNTs was proposed. The method involves a high-temperature annealing ( 2600 degrees C, 1 h) followed by an extraction treatment with a selected dispersing agent. While the annealing process evaporates the metal particles, the extraction treatment removes CNPs. The quality of the nanotubes obtained after purification was examined by laser Raman, thermogravimetric analysis, and electron microscopy observations.

关键词: decomposition;hydrocarbons;temperature;nanofibers;pyrolysis;monoxide;bundles;purity;gas

Van Hove奇异性、非电声作用与HgBa2Cun-1CunO2n+2+δ(n=1,2,3)系统的超导电性

张霞 , 苏希玉 , 侯芹英 , 侯艳丽

低温物理学报 doi:10.3969/j.issn.1000-3258.2008.03.011

考虑态密度的Van Hove奇异性和非电声作用,我们在BCS理论框架内研究了HgBa2Cun-1CunO2n+2+δ(n=1,2,3)系统的超导转变温度和同位素效应.结果表明,当同时考虑Van Hove奇异性和非电声作用时,可以更好地解释HgBa2Cun-1CunO2n+2+δ(n=1,2,3)系统的超导性质.

关键词: Van Hove奇异性 , 非电声作用 , 超导转变温度 , 同位素效应

Van Vleck paramagnetism of europium oxyhydroxide

Hiroaki Samata , Naoki Wada , Tadashi C Ozawa

稀土学报(英文版) doi:10.1016/S1002-0721(14)60399-9

关键词:

Zee-Man石墨炉原子吸收法测定生铁中痕量砷和铅

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

MAn体系分子前线轨道能级与共聚合Q-e概念关系的研究

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

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Potential Response Analysis of Exponentially Decaying Polarizing Current of Electrode and its Use in the Study of Stress Corrosion Cracking(SCC)of Stainless Steel

Yanliang HUANG Ming LU Chunan CAO Haichao LIN Ming LU Corrosion Science Laboratory , Institute of Corrosion and Protection of Metals , Academia Sinica , Shenyang , 110015 , China

材料科学技术（英）

A study on the potential response of exponentially decaying polarizing current of electrode was car- ried out.The appearance of critical point of the potential-time response of exponentially decaying current was ensured from theoretical analysis,and this is the theoretical foundation of the critical point method for the measurement of corrosion current of metals.The comparison of the corrosion currents measured by the critical point and static methods for the system of 321 stainless steel in 0.5N HCI+0.5N NaCI solution at static state shows that the results agree very well.Finally.the tran- sient corrosion currents of 321 stainless steel in 0.5N HCI+0.5N NaCl solution at different strain level are listed.

关键词: exponentially decaying current , null , null