明天物理学的构想

物理学是自然科学的基础,同时又是自然科学发展的前沿。物理学自诞生以来就具有两方面的作用。在精神上,它极大地满足了人们的求知欲,物理学帮助人们越来越深入地认识了自然界;在物质上、它有力地服务、造福于我们人类。     

NCBBH…HNa(H2O)n和CNBBH…HNa(H2O)n(n=1~5)结构与性质的理论研究

为了探索缺电子B-H键作为质子供体形成双氢键复合物的溶剂化效应,分别采用DFT-B3LYP/6-311++G**和CCSD(T)/6-311++G**方法对NCBBH…HNa和CNBBH…HNa及其水合物NCBBH…HNa(H2O)n和CNBBH…HNa(H2O)n(n=1~5)进行了结构优化和相互作用能计算,并利用AIM(atom in molecule)方法分析了H…H键特征,借助前线分子轨道理论探讨了水合物中双氢键形成H-H共价键的本质。结果表明:随着H2O分子数的增加,B-H键拉长,H…H距离缩短,双氢键由离子型向共价型过渡;当H2O分子数达到4时,双氢键相互作用能和NCBBH…HNa与水分子间的相互作用能分别达到-374.21和-306.50 kJ.mol-1,形成了H-H共价键;缺电子B-H键作为质子供体形成双氢键复合物的水合物析出H2的能力比FH…HLi(H2O)n弱。     

Magnetic properties of a Pt/Co₂ FeAl/MgO structure with perpendicular magnetic anisotropy

Microstructures and magnetic properties of Ta/Pt/Co 2 FeAl(CFA)/MgO multilayers are studied to understand perpendicular magnetic anisotropy(PMA) of half-metallic full-Heusler alloy films.PMA is realized in a 2.5-nm CFA film with B2-ordered structure observed by a high resolution transmission electron microscope.It is demonstrated that a high quality interface between the ferromagnetic layer and oxide layer is not essential for PMA.The conversions between in-plane anisotropy and PMA are investigated to study the dependence of magnetic moment on temperature.At the intersection points,the decreasing slope of the saturation magnetization(M s) changes because of the conversions.The dependence of M s on the annealing temperature and MgO thickness is also studied.     

高斯定理、静电场环路定理的成立条件和物理内涵

本文从库仑定律和叠加原理出发，运用逻辑推理，从电通量（电力线）、电场环流（涡旋电场）的角度，定性地讨论高斯定理、静电场环路定理的成立条件和物理内涵。     

A first-principles study of the magnetic properties in boron-doped ZnO

First-principles calculations based on density functional theory are performed to study the origin of ferromagnetism in boron-doped ZnO. It is found that boron atoms tend to reside at Zn sites. The induced Zn vacancy is a key factor for ferromagnetism in Zn1-xBxO (0相似文献   

Magnetic properties of a Pt/Co2FeAl/MgO structure with perpendicular magnetic anisotropy

Microstructures and magnetic properties of Ta/Pt/Co 2 FeAl（CFA）/MgO multilayers are studied to understand perpendicular magnetic anisotropy（PMA） of half-metallic full-Heusler alloy films.PMA is realized in a 2.5-nm CFA film with B2-ordered structure observed by a high resolution transmission electron microscope.It is demonstrated that a high quality interface between the ferromagnetic layer and oxide layer is not essential for PMA.The conversions between in-plane anisotropy and PMA are investigated to study the dependence of magnetic moment on temperature.At the intersection points,the decreasing slope of the saturation magnetization（M s） changes because of the conversions.The dependence of M s on the annealing temperature and MgO thickness is also studied.