Mo掺杂锐钛矿相TiO2磁光性能的第一性原理研究

采用密度泛函理论下的第一性原理平面波超软赝势方法研究了Ti0.97917 Mo0.02083 O2,Ti0.96875 Mo0.03125 O2和Ti30 Mo2 O64超胞模型的晶格常数,能带结构,态密度和吸收光谱分布.研究结果表明,随着Mo掺杂量的增大,掺杂体系的体积逐渐增大,形成能逐渐升高,掺杂越困难.与此同时,掺杂体系吸收带边均显著红移,禁带宽度均变小,所有掺杂体系均转化为n型简并半导体.与未掺杂TiO2相比较,随着Mo掺杂量提高,掺杂体系禁带宽度减小趋势逐渐减弱,吸收光谱红移减弱.同时,体系的磁矩减小.     

Formation and Distribution of Space—Charge in Cross—Linked Polyethylene

The formation and distribution of space-charge in a cross-linked polyethylene(XLPE) sample are investigated by means of pressure wave propagation,infrared spectroscopy and electrostatic force microscopy(EFM).The related mechanism of space-charge distribution and the structure of XLPE are discussed.The EFM images show that quite large quantitative space-charges locate at the surface of spherulites.     

Anomaly in the Charge Radii and Nuclear Structure

The axially deformed relativistic mean field theory is applied to study the isotope shift of charge distributions of odd-Z Pr isotope chain. The nuclear structure associated with the shell and the isotope effect is investigated. The mechanism of the kink in the isotope shift at the neutron magic number N = 82 is revealed to be dependent on the neutron energy level structure at the Fermi energy, demonstrating that the spin-orbit coupling interaction and p-n attraction are well described by the relativistic mean field theory.     

等势条件下两带电导体球的电荷分布

本文通过多重镜像法求解了等势条件下两个带电导体球的电荷分布问题,主要关注两球的电荷量以及平均面电荷密度随两球半径和两球间距的关系.通过选择合适的坐标,给出两导体球接触时,n级镜像电荷电量和位置的通式,及总电量的解析表达式.研究发现,当两导体球直接接触时,两球所带的电荷量可以严格求解,并给出了两球的电荷量之比表达式.随着两等势导体球间距的增大,两球所带的电荷量之比趋于半径之比.本文还讨论了一个导体球的半径趋于0的极限情况,小球与大球的电荷量之比趋于0,平均面电荷密度之比在两球不直接接触时趋于无穷大,而在两球直接接触时趋于π²/6.     

Topomerization of 2-Halo-[9] Annulen Anion at the DFT Level

Topomerization of [9] annulen anion(1)and its 2-fluoro-,2-chloro-and 2-bromo-derivatives(2,3 and 4,respectively)are studied at the HF/6-31G* and B3LYP/6-311++G** levels of theory.The relative ease of topomerization is dependent on the charge distribution and planarity of the ground state and the transition state of 9-membered rings as well as the size and electronegativity of halogen substituent.Consequently,the endo-2-halo-[9] annulen anion topomers become unstable and easily convert to related exo-topomers.Hence,according to the DFT calcu-lations,the order of topomerization energy barrier for endo exo topomerization is 1endo > 2 endo > 3endo.     

聚对苯硫醚掺杂前后的能带结构与导电性的从头计算研究

本文采用LCAO-CO/SCF ab initio方法计算了聚对苯硫醚掺杂前后的能带结构、电荷分布等。由此探讨了聚对苯硫醚可能的导电机理, 定量地研究了其结构与导电性的关系。     

含氟膦叶立德的^1^3C和^3^1P核磁共振研究

本文报道了三十一个含氟磷叶立德的^1^3C和^3^1P核磁共振研究结果, 含氟磷叶立德的通式为: (C6H5)3P=C(X)(CO)Rf, 其测定的核磁共振数据列于下表.     

一维电荷分布系统的电场线

推导一维电荷分布系统的电场线满足的方程,并使用数学软件MatLab将其电场线精确地作出来,其图像既具科学性而又优于传统的手绘图像.     

类卡宾H2C=CLiF的构型及其异构化

本文用解析梯度和RHF/STO-3G方法研究了锂卤类卡宾H2C=CLiF势能面的主要特征, 得到了四种平衡构型及其异构化的过渡态构型. 平衡构型的能量按三元环构型、四元环构型、σ-配合物构型和p-配合物构型的顺序递增. 文中分析了各构型的特点, 给出了偶极矩、电荷分布和前线分子轨道, 并对该类卡宾的化学反应性质进行了讨论.     

甲硫氨酸-脑啡肽的活性位点

用ＡＭ１方法中计算静电势的ＰＭＥＰ子程序了甲硫氨酸－脑啡肽的活性位点。通过计算得到了整个分子的三维空间静电势分布和由静电势导出的各原子的电荷分布。进一步分析,确定模型分子活性位点为酪氨酸残在的叔氨原子和苯酚基、苯丙氨酸残基的苯基及部分氧原子。