A study on the electrical conductivity of multi-walled carbon nanotube aqueous solution

The electrical conductivity was investigated for multi-walled carbon nanotubes (MWNTs) dissolved in chloroform and toluene, respectively. The electrical conductivity remarkably increased with increase in the content of MWNTs, which is in accordance with Archie's equation . Furthermore, a hypothesis of the electronic transport process was proposed to explain the difference between the solution and the solid compound. In addition, the temperature dependence of the electrical conductivity shows that log σ vs. 1/T exist in a good linear relationship. The activation energy of the electrical conductivity decreased with increase in concentration and an inflexion was observed at 60 °C in MWNT/toluene solution.     

Crystallographic report: Bis{[diacetyl‐bis(2,6‐isopropylphenylimine)]nickel(I)(µ‐chloro)}

The first α‐diimine nickel(I) complex having a chloro bridge is reported. The centrosymmetric dinuclear structure of {[ArN?C(Me)C(Me)?NAr]NiCl}₂[Ar?2,6?C₆H₃(i‐Pr)₂] features two chelating α‐diimine ligands and two bridged chlorine atoms, so that a distorted tetrahedral N₂Cl₂ coordination geometry for nickel results. Copyright © 2004 John Wiley & Sons, Ltd.     

安培

安培(1775-1836)，法国物理学家，对数学和化学也有贡献．1775年1月22日生于里昂一个富商家庭．少年时就显出数学才能．他的父亲信奉卢梭的教育思想，供给他大量图书，令其走自学道路，于是他博览群书，吸取营养．卢梭关于植物学的著作燃起他对科学的热情，1802年他在布尔让——布雷斯中央学校任物理学和化学教授；1814年被选为帝国学院教学部成员；1819年主持巴黎大学哲学讲座；1824年担任法兰西学院实验物理学教授．1836年6月10日在巡视法国各大学途经马赛时逝世．终年61岁．     

Effect of ion impinging on the microstructure and field emission of carbon nanotubes

Effects of ion impinging on the microstructure and field electron emission properties of screen-printed carbon nanotube films were investigated. We observed that the plasma treatment modified the microstructure of CNTs along with the remarkable increase of emission site density. With the prolongation of ion impinging time, the emission current falls down first, and then rises up to higher than that of the untreated films. It is proposed that the change of emission characteristics is due to the different emission mechanisms. After the treatment, electrons are emitted predominantly from the nano-nodes on the tube wall instead from the nanotube tips.     

Synthesis and characterization of new bis(1-aryliminomethylenylnaphthalen-2-oxy)nickel complexes and their catalytic behavior for vinyl polymerization of norbornene

The synthesized 1-aryliminomethylenylnaphthalen-2-ol derivatives reacted with nickel chloride to form bis(1-aryliminomethylenylnaphthalen-2-oxy)nickel complexes. All resultant compounds were structurally characterized by elemental analyses, IR and H NMR, and the structures of the formed complexes were elucidated by X-ray crystal structure analysis. The complexes show high catalytic activities for the vinyl polymerization of norbornene in the presence of methylaluminoxane. The catalytic activity variations have been followed by gas chromatography through monitoring the conversion of norbornene.     

力矩教学剖析

力矩在物理课教学中占有举足轻重的地位．力矩的概念并不难理解，但应用起来却涉及到很多知识点，且能翻出不少新花样．让我们来看下面的问题：放在地面上的板条箱(如图)，受到R=120N力的作用．试求该力对点A的力矩：(1)根据力臂计算；(2)根据该力在作用点B处的分力计算；(3)根据该力在作用线上其它某一适当点处的分力计算．