有限分枝分形上的自迴避迹行走

本文考虑在Sierpinski gasket及分支Koch曲线上的自迴避迹行走,运用实空间重整化群技术求出了相应的关联长度临界指数ν。结果表明,在Sierpinski gasket上,自迴避迹行走与自迴避行走属同一普适类;而在较高分枝度(R_max>3)的Koch曲线上,两者属不同普适类。 关键词：     

电偶极子和磁偶极子在外场中受力和力矩公式的一种简明推导

利用电偶极子的电荷密度和磁偶极子的电流密度的表达式,并借助δ函数导出了电偶极子和磁偶极子在外场中所受的力和力矩公式.     

电场方向对电流变液剪切应力的影响

采用分子动力学模拟的方法,研究了电场方向对电流变液剪切应力的影响结果表明由于流体中自发倾斜链的形成,剪切应力对电场方向有明显的依赖关系,并且在某些特定方向应力会显著增强一种关于电流变液理想结构的理论模型计算证实了该结果,这样人们可通过选择电场的最优方向来增强电流变效应,而不需要额外的能量消耗,从而为电流变液走向实用提供了一条可能的途径 关键词：     

Spin plasmonics in magnetism

We discuss a new class of phenomena that we call ＂spin plasmonics＂. It is motivated by three different recent trends of physics research： （i） spintronics, （ii） plasmonics, and （iii） topological properties as is exemplified by the quantized Hall effect. This involves the physics of the ＂magnetic surface plasmon＂ （MSP） which provides for an analog of the edge states discussed in the quantized Hall effect. Their properties can be easily tuned by an external magnetic field. They are coupled to the electromagnetic field and can be injected into metallic structures and induce spin and charge currents and hold the promise of miniturization of nonreciprocal devices.     

Optical pulling force on nanoparticle clusters with gain due to Fano-like resonance

We demonstrate that, in a simple linearly-polarized plane wave, the optical pulling forces on nanoparticle clusters with gain can be induced by the Fano-like resonance. The numerical results based on the full-wave calculation show that the optical pulling forces can be attributed to the recoil forces for the nanoparticle clusters composed of dipolar nanoparticles with three different configurations. Interestingly, the recoil forces giving rise to optical pulling forces are exactly dominated by the coupling term between the electric and magnetic dipoles excited in the nanoparticle clusters, while other higher-order terms have a negligible contribution. In addition, the optical pulling force can be tailored by modulating the Fano-like resonance via either the particle size or the gain magnitude, offering an alternative freedom degree for optical manipulations of particle clusters.     

η配对超导性的平均场理论

我们把在简单 Hubbard 哈密顿中具有非对角长程有序的杨振宁的(?)配对超导图象,在平均场近似的基础上,推广到热力学的研究.获得了决定超导过渡温度 T_c 和能隙参量(?)的方程组并给出数值解.     

用力定理计算hcp-WC的基态性质

本文用Kohn-Sham局域密度泛函理论与力定理,在线性丸盒轨道原子球(LMTO-ASA)近似下,计算了hcp-WC的基态性质,包括平衡晶格常数a,体模量B和纵声波速率v。计算结果与实验值对比表明,晶格常数的误差小于10％,讨论了原子球半径比δ的不同选择方案对计算结果的影响。由电子分波压力随晶格常数的变化,分析了hcp-WC的键合特性。 关键词：