Spin-polarized zero-energy states in BN/C core–shell quantum dots

Boron-nitride (BN) domains in graphene or graphene domains in BN monolayer offer additional freedoms for tuning the electronic properties of these BN/C nanostructures, which is quite crucial for the applications in nanoscale devices. Based on first-principles calculations combined with a simple Hubbard model, we show that the electron zero-energy states (ZESs) of BN/graphene core–shell quantum dots (QDs) in triangular shapes can be well tuned by varying the size and topology of each domain. The net spin of the systems is dominated by the graphene segment which can be described by a Lieb?s theorem. We also demonstrated that a π-electron Hubbard model within a mean-field approximation is implementable in dealing with the electron spin-polarization of BN/C hetero-structured graphene-like materials. This provides an efficient theoretical approach for the BN/C systems where electron spin-polarization is involved.     

纳米银/高聚物复合材料的合成及其抑菌性研究进展

纳米银/高聚物复合材料以其优异的物理化学性质,在近几年得到快速发展。而其在高效抑菌灭菌方面的突出性更是引起科研人员的广泛关注。因此,纳米银/高聚物复合材料的合成方式和抑菌性能具有很大应用研究价值。本文综述了近年来纳米银/高聚物复合材料的制备方法和抑菌效果的比较,并展望了纳米银/高聚物的发展方向及应用前景。