Giant magnetic moment at open ends of multiwalled carbon nanotubes

The attractions of cantilevers made of multiwalled carbon nanotubes(MWNTs)and secured on one end are studied in the non-uniform magnetic field of a permanent magnet.Under an optical microscope,the positions and the corresponding deflections of the original cantilevers(with iron catalytic nanoparticles at the free end)and corresponding cut-off cantilevers(the free ends consisting of open ends of MWNTs)are studied.Both kinds of CNT cantilevers are found to be attracted by the magnet,and the point of application of force is proven to be at the tip of the cantilever.By measuring and comparing deflections between these two kinds of cantilevers,the magnetic moment at the open ends of the CNTs can be quantified.Due to the unexpectedly high value of the magnetic moment at the open ends of carbon nanotubes,it is called giant magnetic moment,and its possible mechanisms are proposed and discussed.     

均匀带电线状体与导体的作用力

基于电磁学理论中的镜像法,利用叠加原理和Mathematica数学软件,计算了均匀带电线状体与接地无限大导体平面和带电导体球的电场力,给出了解析结果,同时绘出了电场力随角度和距离变化的图像.     

Dynamic surface wettability of three-dimensional graphene foam

In this work, three-dimensional graphene foams （GFs） are synthesized and characterized by scanning electron micro- scope （SEM） and Raman spectroscopy. The SEM images indicate that after the growth of graphene, the graphene covers the surface of nickel （Ni） foam uniformly. Raman spectra show that the percentages of monolayer, bilayer, trilayer, and multilayer graphenes are - 58%, - 32%, - 8%, and ,.o 2%, respectively. The contact angle （CA） （-- 12°） of water droplet （3 p-L） on GF is found to be larger than that on Ni foam （,- 107°）, indicating that graphenes have changed the surface wettability of the Ni foam. Meanwhile, the dynamic characteristics of CA of water droplet on GF are different from those on Ni foam. The mechanisms for different behaviors are discussed, which are attributed to volatilization and seepage of water droplets.     

用电势能法求带电细圆环与导体球的作用力

本文用电动力学中的镜像法,利用Mathematica软件计算了当导体球的球心在带电细圆环的轴线上时,在均匀带电细圆环作用下处于静电平衡的导体球外空间的电势,同时绘出导体球外空间的电势分布图像;再运用电势能与电场力的关系求出带电细圆环与导体球的相互作用力,并绘出电场力随距离变化的图像.     

苯酚及其硝基衍生物的酸性递变规律

运用量子化学中HMO和CNDO/2方法,研究苯酚及其硝基衍生物的液相酸性,发现其pk_a和分子中羟基氧上的电荷密度(尤其是π电子密度、π轨道可极化率),以及氧、氢原子间的Wiberg和Mulliken键序之间,存在着良好的线性关系。这有助于从分子的电子微观层次深刻认识本系列炸药及其相关物的酸性递变规律,并可通过简单计算预示一些难以实测分子的离解常数。